WorldWideScience

Sample records for non-contact linear motors

  1. Flux modeling and analysis of a linear induction motor for steel mill non-contacting conveyance system application

    International Nuclear Information System (INIS)

    Liu, C.-T.; Lin, S.-Y.; Yang, Y.-Y.

    2005-01-01

    A detailed mathematical approach for analyzing static/dynamic characteristics of a linear induction motor for steel mill non-contacting conveyance system application will be provided. The dependent reluctances among the motor secondary steel plate and primary poles have been systematically formulated; hence, the operational performance of the system can be derived conveniently. Results showed that not only the motor structure is suitable for the design objective, but also the proposed magnetic equivalent circuit can provide appropriate and convenient modeling for relative analytical investigations

  2. Non-contact measurement of linear external dimensions of the mouse eye.

    Science.gov (United States)

    Wisard, Jeffrey; Chrenek, Micah A; Wright, Charles; Dalal, Nupur; Pardue, Machelle T; Boatright, Jeffrey H; Nickerson, John M

    2010-03-30

    Biometric analyses of quantitative traits in eyes of mice can reveal abnormalities related to refractive or ocular development. Due to the small size of the mouse eye, highly accurate and precise measurements are needed to detect meaningful differences. We sought a non-contact measuring technique to obtain highly accurate and precise linear dimensions of the mouse eye. Laser micrometry was validated with gauge block standards. Simple procedures to measure eye dimensions on three axes were devised. Mouse eyes from C57BL/6J and rd10 on a C57BL/6J background were dissected and extraocular muscle and fat removed. External eye dimensions of axial length (anterior-posterior (A-P) axis) and equatorial diameter (superior-inferior (S-I) and nasal-temporal (N-T) axes) were obtained with a laser micrometer. Several approaches to prevent or ameliorate evaporation due to room air were employed. The resolution of the laser micrometer was less than 0.77 microm, and it provided accurate and precise non-contact measurements of eye dimensions on three axes. External dimensions of the eye strongly correlated with eye weight. The N-T and S-I dimensions of the eye correlated with each other most closely from among the 28 pair-wise combinations of the several parameters that were collected. The equatorial axis measurements correlated well from the right and left eye of each mouse. The A-P measurements did not correlate or correlated poorly in each pair of eyes. The instrument is well suited for the measurement of enucleated eyes and other structures from most commonly used species in experimental vision research and ophthalmology. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  3. Handbook on linear motor application

    International Nuclear Information System (INIS)

    1988-10-01

    This book guides the application for Linear motor. It lists classification and speciality of Linear Motor, terms of linear-induction motor, principle of the Motor, types on one-side linear-induction motor, bilateral linear-induction motor, linear-DC Motor on basic of the motor, linear-DC Motor for moving-coil type, linear-DC motor for permanent-magnet moving type, linear-DC motor for electricity non-utility type, linear-pulse motor for variable motor, linear-pulse motor for permanent magneto type, linear-vibration actuator, linear-vibration actuator for moving-coil type, linear synchronous motor, linear electromagnetic motor, linear electromagnetic solenoid, technical organization and magnetic levitation and linear motor and sensor.

  4. Linear induction motor

    International Nuclear Information System (INIS)

    Barkman, W.E.; Adams, W.Q.; Berrier, B.R.

    1978-01-01

    A linear induction motor has been operated on a test bed with a feedback pulse resolution of 5 nm (0.2 μin). Slewing tests with this slide drive have shown positioning errors less than or equal to 33 nm (1.3 μin) at feedrates between 0 and 25.4 mm/min (0-1 ipm). A 0.86-m (34-in)-stroke linear motor is being investigated, using the SPACO machine as a test bed. Initial results were encouraging, and work is continuing to optimize the servosystem compensation

  5. Segmented rail linear induction motor

    Science.gov (United States)

    Cowan, Jr., Maynard; Marder, Barry M.

    1996-01-01

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces.

  6. Segmented rail linear induction motor

    Science.gov (United States)

    Cowan, M. Jr.; Marder, B.M.

    1996-09-03

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces. 6 figs.

  7. Simulation of linear Switched Reluctance Motor drives

    OpenAIRE

    Garcia Amoros, Jordi; Blanqué Molina, Balduino; Andrada Gascón, Pedro

    2011-01-01

    This paper presents a simulation model of linear switched reluctance motor drives. A Matlab-Simulink environment coupled with finite element analysis is used to perform the simulations. Experimental and simulation results for a double sided linear switched motor drive prototype are reported and compared to verify the simulation model.

  8. Linear Motor for Drive of Belt Conveyor

    Directory of Open Access Journals (Sweden)

    Milan Krasl

    2006-01-01

    Full Text Available This paper introduces a novel approach on the design of a linear motor for drive of belt conveyor (LMBC. The motor is a simple combination of asynchronous motor in plane. The electromagnetic forces is one of the most important parameters of electrical machines. This parameter is necessary for the checking of the design. This paper describes several variants: linear motor with slots in platens, slots in one half of platens and optimization of slots. The electromagnetic force can be found with the help of a Finite Elements Method – based program. For solution was used QuickField program.

  9. Levitation Linear Motors for Precision Positioning

    Science.gov (United States)

    Trumper, David L.

    The author has been active in the development of levitation devices for precision positioning during the last 18 years. Principal among the techniques studied has been the use of two-force or levitation linear motors. These motors have been designed into stages for precision positioning in lithography, scanned probe microscopy, and other precision measurement systems. In such devices, the use of levitation linear motors allows the control of six stage degrees of freedom to nanometer resolution with a single moving part. This paper presents an overview of the operating principles, electromagnetic configurations, and system level performance of levitation linear motors for precision applications. The configuration of such motors is most commonly an iron-free permanent magnet array in the Halbach configuration which is driven by an iron-free multiphase coil set. By properly choosing the phase drive currents, forces in levitation and translation can be controlled. This opens possibilities for novel positioning system configurations and performance capabilities.

  10. Comparison of linear synchronous and induction motors

    Science.gov (United States)

    2004-06-01

    A propulsion prade study was conducted as part of the Colorado Maglev Project of FTA's Urban Maglev Technology Development Program to identify and evaluate prospective linear motor designs that could potentially meet the system performance requiremen...

  11. A linear magnetic motor and generator

    Science.gov (United States)

    Studer, P. A.

    1980-01-01

    In linear magnetic motor and generator suitable for remote and hostile environments, magnetic forces drive reciprocating shaft along its axis. Actuator shaft is located in center of cylindrical body and may be supported by either contacting or noncontacting bearings. When device operates as bidirectional motor, drive coil selectively adds and subtracts magnetic flux to and from flux paths, producing forces that drive actuator along axis. When actuator is driven by external reciprocating engine, device becomes ac generator.

  12. Linear Parameter Varying Control of Induction Motors

    DEFF Research Database (Denmark)

    Trangbæk, Klaus

    The subject of this thesis is the development of linear parameter varying (LPV) controllers and observers for control of induction motors. The induction motor is one of the most common machines in industrial applications. Being a highly nonlinear system, it poses challenging control problems...... for high performance applications. This thesis demonstrates how LPV control theory provides a systematic way to achieve good performance for these problems. The main contributions of this thesis are the application of the LPV control theory to induction motor control as well as various contributions...

  13. High Speed Linear Induction Motor Efficiency Optimization

    Science.gov (United States)

    2005-06-01

    John Wiley and Sons, 1972. [7] Old Dominion University Maglev Train News Report, "Glitches Postpone Debut of Maglev ," October 10, 2002, http...High speed trains and monorails as well as EMALS are just a few of the recent designs using linear motors [7]. 15 In high-speed applications, there is...to the short primary DSLIM and its effect on rapid transit trains with respect to efficiency [6], [14]. As the primary field of the short primary

  14. Comparison of Linear Induction Motor Theories for the LIMRV and TLRV Motors

    Science.gov (United States)

    1978-01-01

    The Oberretl, Yamamura, and Mosebach theories of the linear induction motor are described and also applied to predict performance characteristics of the TLRV & LIMRV linear induction motors. The effect of finite motor width and length on performance ...

  15. Linear pneumatic motors – a comparative study

    Directory of Open Access Journals (Sweden)

    Deaconescu Tudor

    2017-01-01

    Full Text Available The paper presents a comparative study of the performance of single-acting cylinders, diaphragm cylinders and pneumatic muscles, and offers users information that allows the selection of an optimum technical solution. Such a study was necessary, in view of the numerous papers on pneumatic muscle applications found in literature, that assert the superiority of pneumatic muscles over other pneumatic linear motors in relation to quantities like dimensions, mass, developed force or energy-to-mass ratios, however without offering concrete data.

  16. A seismic vertical vibrator driven by linear synchronous motors

    NARCIS (Netherlands)

    Noorlandt, R.P.; Drijkoningen, G.G.; Dams, J.; Jenneskens, R.

    2015-01-01

    A linear synchronous motor (LSM) is an electric motor that can produce large controllable forces and is therefore suitable as a driving engine for a seismic vibrator. This motor consists of two independent elements, a magnet track and a coil track, allowing practically unlimited motor displacements.

  17. Study of linear induction motor characteristics : the Oberretl model

    Science.gov (United States)

    1975-05-30

    The Oberretl theory of the double-sided linear induction motor (LIM) is examined, starting with the idealized model and accompanying assumptions, and ending with relations for predicted thrust, airgap power, and motor efficiency. The effect of varyin...

  18. Study of linear induction motor characteristics : the Mosebach model

    Science.gov (United States)

    1976-05-31

    This report covers the Mosebach theory of the double-sided linear induction motor, starting with the ideallized model and accompanying assumptions, and ending with relations for thrust, airgap power, and motor efficiency. Solutions of the magnetic in...

  19. Quad-copter UAV BLDC Motor Control: Linear v/s non-linear control maps

    Directory of Open Access Journals (Sweden)

    Deep Parikh

    2015-08-01

    Full Text Available This paper presents some investigations and comparison of using linear versus non-linear static motor-control maps for the speed control of a BLDC (Brush Less Direct Current motors used in quad-copter UAV (Unmanned Aerial Vehicles. The motor-control map considered here is the inverse of the static map relating motor-speed output to motor-voltage input for a typical out-runner type Brushless DC Motors (BLDCM.  Traditionally, quad-copter BLDC motor speed control uses simple linear motor-control map defined by the motor-constant specification. However, practical BLDC motors show non-linear characteristic, particularly when operated across wide operating speed-range as is commonly required in quad-copter UAV flight operations. In this paper, our investigations to compare performance of linear versus non-linear motor-control maps are presented. The investigations cover simulation-based and experimental study of BLDC motor speed control systems for  quad-copter vehicle available. First the non-linear map relating rotor RPM to motor voltage for quad-copter BLDC motor is obtained experimentally using an optical speed encoder. The performance of the linear versus non-linear motor-control-maps for the speed control are studied. The investigations also cover study of time-responses for various standard test input-signals e.g. step, ramp and pulse inputs, applied as the reference speed-commands. Also, simple 2-degree of freedom test-bed is developed in our laboratory to help test the open-loop and closed-loop experimental investigations. The non-linear motor-control map is found to perform better in BLDC motor speed tracking control performance and thereby helping achieve better quad-copter roll-angle attitude control.

  20. Experimental development of an ultrasonic linear motor

    CSIR Research Space (South Africa)

    M'Boungui, G

    2010-01-01

    Full Text Available and first trials of the structure characterization are presented. 2 Motor design and working principle Traditionally, ultrasonic motors (USM) exploit the propagation of a travelling wave in a resonator (stator) and the friction intermittently created...

  1. PREFACE: Non-contact AFM Non-contact AFM

    Science.gov (United States)

    Giessibl, Franz J.; Morita, Seizo

    2012-02-01

    This special issue is focussed on high resolution non-contact atomic force microscopy (AFM). Non-contact atomic force microscopy was established approximately 15 years ago as a tool to image conducting and insulating surfaces with atomic resolution. Since 1998, an annual international conference has taken place, and although the proceedings of these conferences are a useful source of information, several key developments warrant devoting a special issue to this subject. In the theoretic field, the possibility of supplementing established techniques such as scanning tunneling microscopy (STM) and Kelvin probe microscopy with atomically resolved force micrsoscopy poses many challenges in the calculation of contrast and contrast reversal. The surface science of insulators, self-assembled monolayers and adsorbates on insulators is a fruitful field for the application of non-contact AFM: several articles in this issue are devoted to these subjects. Atomic imaging and manipulation have been pioneered using STM, but because AFM allows the measurement of forces, AFM has had a profound impact in this field as well. Three-dimensional force spectroscopy has allowed many important insights into surface science. In this issue a combined 3D tunneling and force microscopy is introduced. Non-contact AFM typically uses frequency modulation to measure force gradients and was initially used mainly in a vacuum. As can be seen in this issue, frequency modulation is now also used in ambient conditions, allowing better spatial and force resolution. We thank all of the contributors for their time and efforts in making this special issue possible. We are also very grateful to the staff of IOP Publishing for handling the administrative aspects and for steering the refereeing process. Non-contact AFM contents Relation between the chemical force and the tunnelling current in atomic point contacts: a simple model Pavel Jelínek, Martin Ondrácek and Fernando Flores Theoretical simulation of

  2. A new linear type hydraulic motor

    Science.gov (United States)

    Jiang, Dong; Zhang, Tong; Li, Wenhua; Chen, Xinyang

    2017-08-01

    This paper proposes the design of liner type hydraulic motor on the base of inner curved radial piston hydraulic motor. The hydraulic cylinders of the new type motor are in the straight line which will improve the utilization of the axial space and different out power can be supplied by changes the number of cylinders. In this paper, the structure and working principle of the liner type hydraulic motor is introduced.

  3. A seismic vertical vibrator driven by linear motors

    NARCIS (Netherlands)

    Noorlandt, R.P.; Drijkoningen, G.G.; Schneider, R.M.

    2012-01-01

    In this paper we present a newly developed vertical seismic vibrator driven by linear motors. We explain the different components the vibrator consists of. We show that the harmonic distortion of the linear-motor vibrator signal is very small. We also show that, without applying a feedback loop on

  4. Development of the Floating Centrifugal Pump by Use of Non Contact Magnetic Drive and Its Performance

    Directory of Open Access Journals (Sweden)

    Mitsuo Uno

    2004-01-01

    Full Text Available This article focuses on the impeller construction, non contact driving method and performance of a newly developed shaftless floating pump with centrifugal impeller. The drive principle of the floating impeller pump used the magnet induction method similar to the levitation theory of the linear motor. In order to reduce the axial thrust by the pressure different between shroud and disk side, the balance hole and the aileron blade were installed in the floating impeller. Considering the above effect, floating of an impeller in a pump was realized. Moreover, the performance curves of a developed pump are in agreement with a general centrifugal pump, and the dimensionless characteristic curve also agrees under the different rotational speed due to no mechanical friction of the rotational part. Therefore, utility of a non contacting magnetic-drive style pump with the floating impeller was made clear.

  5. Development of Torsional and Linear Piezoelectrically Driven Motors

    Science.gov (United States)

    Duong, Khanh; Newton, David; Garcia, Ephrahim

    1996-01-01

    The development of rotary and linear inchworm-motors using piezoelectric actuators is presented. The motors' design has the advantage of a macro and micro stepper motor with high load and speed. The torsional design is capable of fast angular positioning with micro level accuracy. Additionally, the rotary motor, as designed, can be used as a clutch/brake mechanism. Constructed prototype motors of both types along with their characteristics are presented. The torsional motor consists of a torsional section that provides angular displacement and torque, and two alternating clamping sections which provide the holding force. The motor relies on the principal piezoelectric coupling coefficient (d33) with no torsional elements, increasing its torque capability. The linear motor consists of a longitudinal vibrator that provides displacement and load, and two alternating clamping sections which provide the holding force. This design eliminates bending moment, tension and shear applied to the actuator elements, increase its load capability and life. Innovative flexure designs have been introduced for both motor types. Critical issues that affect the design and performance of the motors are explored and discussed. Experiments are performed demonstrating the motor prototypes based on the aforementioned design considerations.

  6. Implementation of feedback-linearization-modelled induction motor ...

    Indian Academy of Sciences (India)

    RABI NARAYAN MISHRA

    2017-11-27

    Nov 27, 2017 ... single input introduced here is an error (speed and torque) instead of two inputs, error and change in error, as in the conventional NFC. ... Feedback linearization; induction motor; neuro-fuzzy controller; stationary reference frame. 1. Introduction ... replacing costly, heavy DC motor drive. However, FOC.

  7. Direct Torque Control With Feedback Linearization for Induction Motor Drives

    DEFF Research Database (Denmark)

    Lascu, Cristian; Jafarzadeh, Saeed; Fadali, Sami M.

    2017-01-01

    This paper describes a direct-torque-controlled (DTC) induction motor (IM) drive that employs feedback linearization and sliding-mode control (SMC). A new feedback linearization approach is proposed, which yields a decoupled linear IM model with two state variables: torque and stator flux magnitu...... in simulations. The sliding controller is compared with a linear DTC scheme with and without feedback linearization. Extensive experimental results for a sensorless IM drive validate the proposed solution.......This paper describes a direct-torque-controlled (DTC) induction motor (IM) drive that employs feedback linearization and sliding-mode control (SMC). A new feedback linearization approach is proposed, which yields a decoupled linear IM model with two state variables: torque and stator flux magnitude...

  8. Linear stability analysis in a solid-propellant rocket motor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.M.; Kang, K.T.; Yoon, J.K. [Agency for Defense Development, Taejon (Korea, Republic of)

    1995-10-01

    Combustion instability in solid-propellant rocket motors depends on the balance between acoustic energy gains and losses of the system. The objective of this paper is to demonstrate the capability of the program which predicts the standard longitudinal stability using acoustic modes based on linear stability analysis and T-burner test results of propellants. Commercial ANSYS 5.0A program can be used to calculate the acoustic characteristic of a rocket motor. The linear stability prediction was compared with the static firing test results of rocket motors. (author). 11 refs., 17 figs.

  9. Robust linear parameter varying induction motor control with polytopic models

    Directory of Open Access Journals (Sweden)

    Dalila Khamari

    2013-01-01

    Full Text Available This paper deals with a robust controller for an induction motor which is represented as a linear parameter varying systems. To do so linear matrix inequality (LMI based approach and robust Lyapunov feedback controller are associated. This new approach is related to the fact that the synthesis of a linear parameter varying (LPV feedback controller for the inner loop take into account rotor resistance and mechanical speed as varying parameter. An LPV flux observer is also synthesized to estimate rotor flux providing reference to cited above regulator. The induction motor is described as a polytopic model because of speed and rotor resistance affine dependence their values can be estimated on line during systems operations. The simulation results are presented to confirm the effectiveness of the proposed approach where robustness stability and high performances have been achieved over the entire operating range of the induction motor.

  10. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    Science.gov (United States)

    Coffey, Howard T.

    1993-01-01

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.

  11. Research of Linear Translation Devices with Stepper Motor

    Directory of Open Access Journals (Sweden)

    Dmitrij Komissarov

    2016-04-01

    Full Text Available In order to ensure accuracy of motorized linear translation stages theoretical and experimental investigations were performed, that allow to establish moving platform vibration level depending of operating modes (different velocities and used lubricant in the system. Lubricants had different viscosity, which has effect to the system moving smoothness, sound level and vibration level of the stage. Such work gives possibility to done conclusions: with what lubricant or with what viscosity of the lubricant motorized linear translation stage works smoother, with less noise and vib-ration level, and also show best movement characteristics.

  12. A novel linear switched reluctance motor : Investigation and experimental verification

    Directory of Open Access Journals (Sweden)

    Rengasamy Arumugam

    2011-02-01

    Full Text Available A novel stator geometry for a linear switched reluctance motor (LSRM that improves the force profile is presented inthis paper. In the new geometry, pole shoes are affixed on the stator poles. Static characteristics for the proposed structurehave been highlighted using two dimensional (2-D finite element analyses (FEA. A detailed sensitivity analysis of the effectof several geometrical parameters on the performance of the proposed LSRM is presented. Further, motor performance forvariable load conditions is discussed. The 2-D FEA results and the experimental results of this paper prove that LSRMs areone of the strong candidates for linear propulsion drives.

  13. Comparative analysis of linear motor geometries for Stirling coolers

    Science.gov (United States)

    R, Rajesh V.; Kuzhiveli, Biju T.

    2017-12-01

    Compared to rotary motor driven Stirling coolers, linear motor coolers are characterized by small volume and long life, making them more suitable for space and military applications. The motor design and operational characteristics have a direct effect on the operation of the cooler. In this perspective, ample scope exists in understanding the behavioural description of linear motor systems. In the present work, the authors compare and analyze different moving magnet linear motor geometries to finalize the most favourable one for Stirling coolers. The required axial force in the linear motors is generated by the interaction of magnetic fields of a current carrying coil and that of a permanent magnet. The compact size, commercial availability of permanent magnets and low weight requirement of the system are quite a few constraints for the design. The finite element analysis performed using Maxwell software serves as the basic tool to analyze the magnet movement, flux distribution in the air gap and the magnetic saturation levels on the core. A number of material combinations are investigated for core before finalizing the design. The effect of varying the core geometry on the flux produced in the air gap is also analyzed. The electromagnetic analysis of the motor indicates that the permanent magnet height ought to be taken in such a way that it is under the influence of electromagnetic field of current carrying coil as well as the outer core in the balanced position. This is necessary so that sufficient amount of thrust force is developed by efficient utilisation of the air gap flux density. Also, the outer core ends need to be designed to facilitate enough room for the magnet movement under the operating conditions.

  14. Evaluation of linear induction motor characteristics : the Yamamura model

    Science.gov (United States)

    1975-04-30

    The Yamamura theory of the double-sided linear induction motor (LIM) excited by a constant current source is discussed in some detail. The report begins with a derivation of thrust and airgap power using the method of vector potentials and theorem of...

  15. CONTRIBUTIONS TO THE FINITE ELEMENT MODELING OF LINEAR ULTRASONIC MOTORS

    Directory of Open Access Journals (Sweden)

    Oana CHIVU

    2013-05-01

    Full Text Available The present paper is concerned with the main modeling elements as produced by means of thefinite element method of linear ultrasonic motors. Hence, first the model is designed and then a modaland harmonic analysis are carried out in view of outlining the main outcomes

  16. Implementation of feedback-linearization-modelled induction motor ...

    Indian Academy of Sciences (India)

    RABI NARAYAN MISHRA

    2017-11-27

    Nov 27, 2017 ... It is evident from the comparative results that the system performance is not deteriorated using the proposed simple NFC as compared to the conventional NFC; rather, it shows superior performance over PI-controller-based drive. Keywords. Feedback linearization; induction motor; neuro-fuzzy controller; ...

  17. Position sensor for linear synchronous motors employing halbach arrays

    Science.gov (United States)

    Post, Richard Freeman

    2014-12-23

    A position sensor suitable for use in linear synchronous motor (LSM) drive systems employing Halbach arrays to create their magnetic fields is described. The system has several advantages over previously employed ones, especially in its simplicity and its freedom from being affected by weather conditions, accumulated dirt, or electrical interference from the LSM system itself.

  18. Thermally driven molecular linear motors - A molecular dynamics study

    DEFF Research Database (Denmark)

    Zambrano, Harvey A; Walther, Jens Honore; Jaffe, Richard Lawrence

    2009-01-01

    We conduct molecular dynamics simulations of a molecular linear motor consisting of coaxial carbon nanotubes with a long outer carbon nanotube confining and guiding the motion of an inner short, capsule-like nanotube. The simulations indicate that the motion of the capsule can be controlled...

  19. Generate stepper motor linear speed profile in real time

    Science.gov (United States)

    Stoychitch, M. Y.

    2018-01-01

    In this paper we consider the problem of realization of linear speed profile of stepper motors in real time. We considered the general case when changes of speed in the phases of acceleration and deceleration are different. The new and practical algorithm of the trajectory planning is given. The algorithms of the real time speed control which are suitable for realization to the microcontroller and FPGA circuits are proposed. The practical realization one of these algorithms, using Arduino platform, is given also.

  20. Linear motor driven Stirling coolers for military and commercial applications

    International Nuclear Information System (INIS)

    Berry, R.

    1992-01-01

    This paper discusses the design and performance of a miniature, closed cycle, split stirling, cryogenic cooler that provides 1 watt of cooling at 80 K. The compressor uses two opposed linear motors to drive opposed pistons and the expander uses a pneumatically driven displacer. A single electronics module and compressor has been developed to drive three different expanders that have nominal cold cylinder diameters of 5, 8 and 13 mm

  1. NASTRAN buckling study of a linear induction motor reaction rail

    Science.gov (United States)

    Williams, J. G.

    1973-01-01

    NASTRAN was used to study problems associated with the installation of a linear induction motor reaction rail test track. Specific problems studied include determination of the critical axial compressive buckling stress and establishment of the lateral stiffness of the reaction rail under combined loads. NASTRAN results were compared with experimentally obtained values and satisfactory agreement was obtained. The reaction rail was found to buckle at an axial compressive stress of 11,400 pounds per square inch. The results of this investigation were used to select procedures for installation of the reaction rail.

  2. Analysis of Nonlinear Dynamics in Linear Compressors Driven by Linear Motors

    Science.gov (United States)

    Chen, Liangyuan

    2018-03-01

    The analysis of dynamic characteristics of the mechatronics system is of great significance for the linear motor design and control. Steady-state nonlinear response characteristics of a linear compressor are investigated theoretically based on the linearized and nonlinear models. First, the influence factors considering the nonlinear gas force load were analyzed. Then, a simple linearized model was set up to analyze the influence on the stroke and resonance frequency. Finally, the nonlinear model was set up to analyze the effects of piston mass, spring stiffness, driving force as an example of design parameter variation. The simulating results show that the stroke can be obtained by adjusting the excitation amplitude, frequency and other adjustments, the equilibrium position can be adjusted by adjusting the DC input, and to make the more efficient operation, the operating frequency must always equal to the resonance frequency.

  3. 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.

  4. Linear magnetic spring and spring/motor combination

    Science.gov (United States)

    Patt, Paul J. (Inventor); Stolfi, Fred R. (Inventor)

    1991-01-01

    A magnetic spring, or a spring and motor combination, providing a linear spring force characteristic in each direction from a neutral position, in which the spring action may occur for any desired coordinate of a typical orthogonal coordinate system. A set of magnets are disposed, preferably symmetrically about a coordinate axis, poled orthogonally to the desired force direction. A second set of magnets, respectively poled opposite the first set, are arranged on the sprung article. The magnets of one of the sets are spaced a greater distance apart than those of the other, such that an end magnet from each set forms a pair having preferably planar faces parallel to the direction of spring force, the faces being offset so that in a neutral position the outer edge of the closer spaced magnet set is aligned with the inner edge of the greater spaced magnet set. For use as a motor, a coil can be arranged with conductors orthogonal to both the magnet pole directions and the direction of desired spring force, located across from the magnets of one set and fixed with respect to the magnets of the other set. In a cylindrical coordinate system having axial spring force, the magnets are radially poled and motor coils are concentric with the cylinder axis.

  5. Dynamic Performance of Subway Vehicle with Linear Induction Motor System

    Science.gov (United States)

    Wu, Pingbo; Luo, Ren; Hu, Yan; Zeng, Jing

    The light rail vehicle with Linear Induction Motor (LIM) bogie, which is a new type of urban rail traffic tool, has the advantages of low costs, wide applicability, low noise, simple maintenance and better dynamic behavior. This kind of vehicle, supported and guided by the wheel and rail, is not driven by the wheel/rail adhesion force, but driven by the electromagnetic force between LIM and reaction plate. In this paper, three different types of suspensions and their characteristic are discussed with considering the interactions both between wheel and rail and between LIM and reaction plate. A nonlinear mathematical model of the vehicle with LIM bogie is set up by using the software SIMPACK, and the electromechanical model is also set up on Simulink roof. Then the running behavior of the LIM vehicle is simulated, and the influence of suspension on the vehicle dynamic performance is investigated.

  6. 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)

  7. Optimization of a piezoelectric linear motor in terms of the contact parameters

    International Nuclear Information System (INIS)

    Ko, Hyun-Phill; Kim, Sangsig; Kang, Chong-Yun; Kim, Hyun-Jai; Yoon, Seok-Jin

    2005-01-01

    The contact kinetics of piezoelectric linear motors determines the operational characteristics like speed and torque or transmitted mechanical power and efficiency. Piezoelectric linear motors are driven by tangential stress in the interface between tip of shaking beam and slider. A good contact between the tip and slider is necessary for a reliable analysis of the motor, which is needed for the optimization of its performance. The piezoelectric linear motor was fabricated and the characteristics of the motor were investigated by external conditions such as tip shape with different curvatures and contact force between the tip and the slider. It was found in this investigation that the optimal curvature of the tip and the contact force are curvature of 1 and 10, respectively, for the high actuating speed, and curvature of 1 and 40 N, respectively, for the high actuating force. Finally, tip shape has an influence on the characteristics of linear motor

  8. Direct torque control via feedback linearization for permanent magnet synchronous motor drives

    DEFF Research Database (Denmark)

    Lascu, Cristian; Boldea, Ion; Blaabjerg, Frede

    2012-01-01

    The paper describes a direct torque controlled (DTC) permanent magnet synchronous motor (PMSM) drive that employs feedback linearization and uses sliding-mode and linear controllers. We introduce a new feedback linearization approach that yields a decoupled linear PMSM model with two state...

  9. Influence analysis of structural parameters on electromagnetic properties of HTS linear induction motor

    International Nuclear Information System (INIS)

    Zhao, J.; Zheng, T.Q.; Zhang, W.; Fang, J.; Liu, Y.M.

    2011-01-01

    A new type high temperature superconductor linear induction motor is designed and analyzed as a prototype to ensure applicability aimed at industrial motors. Made of Bi-2223/Ag, primary windings are distributed with the double-layer concentrated structure. The motor is analyzed by 2D electromagnetic Finite Element Method to get magnetic field distribution, thrust force, vertical force and so on. The critical current of motor and the electromagnetic force are mostly decided by the leakage flux density of primary slot and by the main magnetic flux and eddy current respectively. The structural parameters of motor have a great influence on the distribution of magnetic field. Under constant currents, the properties of motor are analyzed with different slot widths, slot heights and winding turns. The properties of motor, such as the maximum slot leakage flux density, motor thrust and motor vertical force, are analyzed with different structural parameters.

  10. Analysis and comparison of end effects in linear switched reluctance and hybrid motors

    Science.gov (United States)

    Barhoumi, El Manaa; Abo-Khalil, Ahmed Galal; Berrouche, Youcef; Wurtz, Frederic

    2017-03-01

    This paper presents and discusses the longitudinal and transversal end effects which affects the propulsive force of linear motors. Generally, the modeling of linear machine considers the forces distortion due to the specific geometry of linear actuators. The insertion of permanent magnets on the stator allows improving the propulsive force produced by switched reluctance linear motors. Also, the inserted permanent magnets in the hybrid structure allow reducing considerably the ends effects observed in linear motors. The analysis was conducted using 2D and 3D finite elements method. The permanent magnet reinforces the flux produced by the winding and reorients it which allows modifying the impact of end effects. Presented simulations and discussions show the importance of this study to characterize the end effects in two different linear motors.

  11. Dynamic Model Based Vector Control of Linear Induction Motor

    Science.gov (United States)

    2012-05-01

    sensorless control is critical for LIM control in some special case. Reference [13] introduces a direct torque and flux control based on space...Industry Applications, IEEE Transactions on, vol. 28, no. 5, pp. 1054–1061, 1992. [4] J. Nash, “ Direct torque control , induction motor vector ...13] C. Lascu, I. Boldea, and F. Blaabjerg, “A modified direct torque control for induction motor sensorless drive,” Industry Applications,

  12. Direct torque control with feedback linearization for induction motor drives

    DEFF Research Database (Denmark)

    Lascu, Cristian; Jafarzadeh, Saeed; Fadali, Sami M.

    2015-01-01

    This paper describes a Direct Torque Controlled (DTC) Induction Machine (IM) drive that employs feedback linearization and sliding-mode control. A feedback linearization approach is investigated, which yields a decoupled linear IM model with two state variables: torque and stator flux magnitude...

  13. Linear summation of outputs in a balanced network model of motor cortex.

    Science.gov (United States)

    Capaday, Charles; van Vreeswijk, Carl

    2015-01-01

    Given the non-linearities of the neural circuitry's elements, we would expect cortical circuits to respond non-linearly when activated. Surprisingly, when two points in the motor cortex are activated simultaneously, the EMG responses are the linear sum of the responses evoked by each of the points activated separately. Additionally, the corticospinal transfer function is close to linear, implying that the synaptic interactions in motor cortex must be effectively linear. To account for this, here we develop a model of motor cortex composed of multiple interconnected points, each comprised of reciprocally connected excitatory and inhibitory neurons. We show how non-linearities in neuronal transfer functions are eschewed by strong synaptic interactions within each point. Consequently, the simultaneous activation of multiple points results in a linear summation of their respective outputs. We also consider the effects of reduction of inhibition at a cortical point when one or more surrounding points are active. The network response in this condition is linear over an approximately two- to three-fold decrease of inhibitory feedback strength. This result supports the idea that focal disinhibition allows linear coupling of motor cortical points to generate movement related muscle activation patterns; albeit with a limitation on gain control. The model also explains why neural activity does not spread as far out as the axonal connectivity allows, whilst also explaining why distant cortical points can be, nonetheless, functionally coupled by focal disinhibition. Finally, we discuss the advantages that linear interactions at the cortical level afford to motor command synthesis.

  14. A T-shape linear piezoelectric motor with single foot.

    Science.gov (United States)

    Liu, Yingxiang; Chen, Weishan; Yang, Xiaohui; Liu, Junkao

    2015-02-01

    A new T-shape piezoelectric motor using the hybrid of two orthogonal longitudinal vibrations is proposed in this work. Six pieces of PZT ceramic plates are bonded on the upside and downside surfaces of a T-shape duralumin alloy base respectively to form the proposed motor. Elliptical movement can be generated on the driving tip by applying sine and cosine voltages to the PZT elements. The horizontal displacement of the driving tip will push the runner while the vertical displacement can overcome the preload. Finite element method is used to accomplish the design and analysis process. The resonance frequencies of the two vibration modes are tuned to be close by modal analysis, while the motion trajectory of the driving tip is observed by transient analysis. After the fabrication of a prototype, the vibration characteristics and mechanical output ability are measured. The no-load speed and the maximum output thrust force of the proposed motor are tested to be 718 mm/s and 3.5 N under an exciting frequency of 53.1 kHz. The proposed T-shape piezoelectric motor exhibits merits of simple structure, easy to realize miniaturization, easy to be fabricated, and high power-to-weight ratio. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Effect of Frequency and Spatial-Harmonics on Rotary and Linear Induction Motor Characteristics

    Science.gov (United States)

    1972-03-01

    A computer analysis is made of the effect of current and MMF airgap harmonics on the output characteristics of rotary and linear induction motors. The current harmonics accompanying thyristor-control operation are evaluated by Fourier analyzing the p...

  16. Coreless Linear Induction Motor (LIM) for Space-borne Electro-magnetic Mass Driver Applications

    Data.gov (United States)

    National Aeronautics and Space Administration — Large scale linear induction motors use ferromagnetic cores, but at high speed these cores choke the system’s ability to transform electrical energy into mechanical...

  17. Development of a sub-nanometer positioning device: combining a new linear motor with linear motion ball guide ways

    International Nuclear Information System (INIS)

    Otsuka, J; Tanaka, T; Masuda, I

    2010-01-01

    A new type of linear motor described in this note has some advantages compared with conventional motors. The attractive magnetic force between the stator (permanent magnets) and mover (armature) is diminished almost to zero. The efficiency is better because the magnetic flux leakage is very small, the size of motor is smaller and detent (force ripple) is smaller than for conventional motors. Therefore, we think that this motor is greatly suitable for ultra-precision positioning as an actuator. An ultra-precision positioning device using this motor and linear motion ball guide ways is newly developed by making the device very rigid and using a suitable control method. Moreover, the positioning performance is evaluated by a positioning resolution, and deviation and dispersion errors. As a result of repeated step response tests, the positioning resolution is 0.3 nm, with the deviation error and dispersion error (3σ) being sub-nanometer. Consequently, the positioning device achieves sub-nanometer positioning. (technical design note)

  18. Principle and analysis of a linear motor driving system for HTS levitation applications

    International Nuclear Information System (INIS)

    Jin, Jian X.; Guo, You G.; Zhu, Jian G.

    2007-01-01

    High temperature superconductor (HTS) high levitation force density with passive and self-stabilizing features allows a number of special applications to be developed. Linear motor driving systems are commonly required for those applications such as levitated transport systems. In this paper a prototype linear motor driving system with HTS is analyzed with calculation details including its magnetic fields and driving forces presented in the paper

  19. Motor and Thermodynamic Losses in Linear Cryocooler Compressors

    Science.gov (United States)

    Reed, J.; Bailey, P. B.; Dadd, M. W.; Davis, T.

    2006-04-01

    Stirling cycle and Pulse Tube cryocoolers can be described by ideal thermodynamic cycles with discrete losses, however experiments show a systematic underestimate of power consumed. Existing correlations have been unable to explain the magnitude of this additional `compression loss', but it can account for up to 50% of the power delivered to the gas. It appears that even a modest decrease could significantly improve the efficiency of future machines. One problem inherent in studying this effect is the complex geometry of cryocoolers. Experiments have therefore been performed on an existing `Oxford type' moving coil compressor with the simplest compression space geometry, a flat cylinder head. Measurements were made of the intrinsic motor losses (including windage), and the power delivered to the gas. The results show that for this machine the motor losses are greater than previously thought, accounting for up to 30% of the compression loss in the original cryocooler configuration. Measurements of the heat transfer losses are also presented.

  20. Evaluation of synthetic linear motor-molecule actuation energetics

    OpenAIRE

    Brough, Branden; Northrop, Brian H.; Schmidt, Jacob J.; Tseng, Hsian-Rong; Houk, Kendall N.; Stoddart, J. Fraser; Ho, Chih-Ming

    2006-01-01

    By applying atomic force microscope (AFM)-based force spectroscopy together with computational modeling in the form of molecular force-field simulations, we have determined quantitatively the actuation energetics of a synthetic motor-molecule. This multidisciplinary approach was performed on specifically designed, bistable, redox-controllable [2]rotaxanes to probe the steric and electrostatic interactions that dictate their mechanical switching at the single-molecule level. The fusion of expe...

  1. Stepping motor adaptor actuator for a commercial uhv linear motion feedthrough

    International Nuclear Information System (INIS)

    Iarocci, M.; Oversluizen, T.

    1989-01-01

    An adaptor coupling has been developed that will allow the attachment of a standard stepping motor to a precision commercial (Varian) uhv linear motion feedthrough. The assembly, consisting of the motor, motor adaptor, limit switches, etc. is clamped to the feedthrough body which can be done under vacuum conditions if necessary. With a 500 step/rev. stepping motor the resolution is 1.27 μm per step. We presently use this assembly in a remote location for the precise positioning of a beam sensing monitor. 2 refs., 3 figs

  2. Design optimization of a linear permanent magnet synchronous motor for extra low force pulsations

    International Nuclear Information System (INIS)

    Isfahani, Aarsh Hassanpour; Vaez-Zadeh, Sadegh

    2007-01-01

    Air cored linear permanent magnet synchronous motors have essentially low force pulsations due to the lack of the primary iron core and teeth. However, a motor design with much lower force pulsations is required for many precise positioning systems, as in fabrication of microelectronic chips. This paper presents the design optimization of an air cored linear permanent magnet synchronous motor with extra low force pulsations for such applications. In order to achieve the goal, an analytical layer model of the machine is developed. A very effective objective function regarding force pulsations is then proposed; while the selected motor dimensions are regarded as the design variables. A genetic algorithm is used to find the optimal motor dimensions. This results in a substantial ninety percent reduction in the force pulsations. The design optimization is verified by a finite element method

  3. Analysis and modeling of different topologies for linear switched reluctance motor using finite element method

    Directory of Open Access Journals (Sweden)

    Babak Ganji

    2016-09-01

    Full Text Available In the present paper, an electromagnetic simulation model is introduced for the conventional type of linear switched reluctance motor (LSRM in which the dynamic characteristics of the motor are predicted precisely by carrying out 2D finite element (FE transient analysis using ANSYS FE package. The simulation model is created totally in ANSYS parametric design language (APDL as a parametric model and it can be used easily for different designs of the conventional LSRMs. Introducing linear switched reluctance motor with segmental translator as a new type of LSRM, performance principles and design criteria are presented for two various topologies of this motor. Carrying out 2D FE transient analysis, dynamic characteristics of these two motors are predicted and compared to those obtained for the conventional LSRM.

  4. Modular Architecture of a Non-Contact Pinch Actuation Micropump

    Directory of Open Access Journals (Sweden)

    Ruzairi Abdul Rahim

    2012-09-01

    Full Text Available This paper demonstrates a modular architecture of a non-contact actuation micropump setup. Rapid hot embossing prototyping was employed in micropump fabrication by using printed circuit board (PCB as a mold material in polymer casting. Actuator-membrane gap separation was studied, with experimental investigation of three separation distances: 2.0 mm, 2.5 mm and 3.5 mm. To enhance the micropump performance, interaction surface area between plunger and membrane was modeled via finite element analysis (FEA. The micropump was evaluated against two frequency ranges, which comprised a low driving frequency range (0–5 Hz, with 0.5 Hz step increments and a nominal frequency range (0–80 Hz, with 10 Hz per step increments. The low range frequency features a linear relationship of flow rate with the operating frequency function, while two magnitude peaks were captured in the flow rate and back pressure characteristic in the nominal frequency range. Repeatability and reliability tests conducted suggest the pump performed at a maximum flow rate of 5.78 mL/min at 65 Hz and a backpressure of 1.35 kPa at 60 Hz.

  5. Cogging force rejection method of linear motor based on internal model principle

    Science.gov (United States)

    Liu, Yang; Chen, Zhenyu; Yang, Tianbo

    2015-02-01

    The cogging force disturbance of linear motor is one of the main factors affecting the positioning accuracy of ultraprecision moving platform. And this drawback could not be completely overcome by improving the design of motor body, such as location modification of permanent magnet array, or optimization design of the shape of teeth-slot. So the active compensation algorithms become prevalent in cogging force rejection area. This paper proposed a control structure based on internal mode principle to attenuate the cogging force of linear motor which deteriorated the accuracy of position, and this structure could make tracking and anti-disturbing performance of close-loop designed respectively. In the first place, the cogging force was seen as the intrinsic property of linear motor and its model constituting controlled object with motor ontology model was obtained by data driven recursive identification method. Then, a control structure was designed to accommodate tracking and anti-interference ability separately by using internal model principle. Finally, the proposed method was verified in a long stroke moving platform driven by linear motor. The experiment results show that, by employing this control strategy, the positioning error caused by cogging force was decreased by 70%.

  6. A rod type linear ultrasonic motor utilizing longitudinal traveling waves: proof of concept

    Science.gov (United States)

    Wang, Liang; Wielert, Tim; Twiefel, Jens; Jin, Jiamei; Wallaschek, Jörg

    2017-08-01

    This paper proposes a non-resonant linear ultrasonic motor utilizing longitudinal traveling waves. The longitudinal traveling waves in the rod type stator are generated by inducing longitudinal vibrations at one end of the waveguide and eliminating reflections at the opposite end by a passive damper. Considering the Poisson’s effect, the stator surface points move on elliptic trajectories and the slider is driven forward by friction. In contrast to many other flexural traveling wave linear ultrasonic motors, the driving direction of the proposed motor is identical to the wave propagation direction. The feasibility of the motor concept is demonstrated theoretically and experimentally. First, the design and operation principle of the motor are presented in detail. Then, the stator is modeled utilizing the transfer matrix method and verified by experimental studies. In addition, experimental parameter studies are carried out to identify the motor characteristics. Finally, the performance of the proposed motor is investigated. Overall, the results indicate very dynamic drive characteristics. The motor prototype achieves a maximum mean velocity of 115 mm s-1 and a maximum load of 0.25 N. Thereby, the start-up and shutdown times from the maximum speed are lower than 5 ms.

  7. Torque linearizing hardware for the electric joint motors of a direct-drive robot

    Science.gov (United States)

    Muir, P. F.; Bryan, J. R.

    Many emerging high-performance robot control algorithms require the command of the joint torques, yet no known commercial robots provide such a capability. We describe the design, development, testing, and application of a VMEbus-based torque linearizing joint interface board (JIB). One JIB resides between the robot control processor and each joint motor amplifier. The JIB provides the control processor with the capability to read the motor position and apply accurate motor torques. The torque command capability derives from the application of a 128k x 8 EPROM lookup table for each motor phase. Because joint motor torque is dependent upon the torque command and the motor position, the hardware is designed to utilize the torque command and the current motor position as the address to retrieve the proper pulse-width for the PWM motor amplifier. The table look-up cycle operates independently of the robot controller at a 40KHz rate to provide constant joint torque as the motor rotates. We identify the proper table entries by an automated in situ data collection procedure. Static torque generation results show that the torque deviations are reduced from as much as 76 percent to below 5 percent for each of the three direct-drive motors (two are variable reluctance motors and one is brushless DC) on an AdeptTwo robot. These torque deviations are reduced below 2.5 percent if only the upper 90 percent of the torque range is considered. The torque deviations of the non-direct-drive joint are reduced by 50 percent. Dynamic robot edge following experiments show that the robot speed of operation can be more than doubled for a given applied force accuracy by utilizing the joint torque linearizing boards.

  8. Inductive Non-Contact Position Sensor

    Science.gov (United States)

    Youngquist, Robert; Garcia, Alyssa; Simmons, Stephen

    2010-01-01

    Optical hardware has been developed to measure the depth of defects in the Space Shuttle Orbiter's windows. In this hardware, a mirror is translated such that its position corresponds to the defect's depth, so the depth measurement problem is transferred to a mirror-position measurement problem. This is preferable because the mirror is internal to the optical system and thus accessible. Based on requirements supplied by the window inspectors, the depth of the defects needs to be measured over a range of 200 microns with a resolution of about 100 nm and an accuracy of about 400 nm. These same requirements then apply to measuring the position of the mirror, and in addition, since this is a scanning system, a response time of about 10 ms is needed. A market search was conducted and no sensor that met these requirements that also fit into the available housing volume (less than one cubic inch) was found, so a novel sensor configuration was constructed to meet the requirements. This new sensor generates a nearly linearly varying magnetic field over a small region of space, which can easily be sampled, resulting in a voltage proportional to position. Experiments were done with a range of inductor values, drive voltages, drive frequencies, and inductor shapes. A rough mathematical model was developed for the device that, in most aspects, describes how it operates and what electrical parameters should be chosen for best performance. The final configuration met all the requirements, yielding a small rugged sensor that was easy to use and had nanometer resolution over more than the 200-micron range required. The inductive position sensor is a compact device (potentially as small as 2 cubic centimeters), which offers nanometer-position resolution over a demonstrated range of nearly 1 mm. One of its advantages is the simplicity of its electrical design. Also, the sensor resolution is nearly uniform across its operational range, which is in contrast to eddy current and

  9. Induction Motor Drive System Based on Linear Active Disturbance Rejection Controller

    Science.gov (United States)

    Liu, Liying; Zhang, Yongli; Yao, Qingmei

    It is difficult to establish an exact mathematical model for the induction motor and the robustness is poor of the vector control system using PI regulator. This paper adopts the linear active disturbance rejection controller (LADRC) to control inductor motor. LADRC doesn't need the exact mathematical model of motor and it can not only estimate but also compensate the general disturbance that includes the coupling items in model of motor and parameters perturbations by linear extended state observer (LESO), so the rotor flux and torque fully decouple. As a result, the performance is improved. To prove the above control scheme, the proposed control system has been simulated in MATLAB/SIMULINK, and the comparison was made with PID. Simulation results show that LADRC' has better performance and robustness than PID.

  10. Linear summation of outputs in a balanced network modelof motor cortex

    Directory of Open Access Journals (Sweden)

    Charles eCapaday

    2015-06-01

    Full Text Available Given the nonlinearities of the the neural circuitry's elements, we would expect corticalcircuits to respond nonlinearly when activated. Surprisingly, when two points in the motorcortex are activated simultaneously, the EMG responses are the linear sum of the responsesevoked by each of the points activated separately. Additionally, the corticospinal transferfunction is close to linear, implying that the synaptic interactions in motor cortex must beeffectively linear. To account for this, here we develop a model of motor cortex composedof multiple interconnected points, each comprised of reciprocally connected excitatory andinhibitory neurons. We show how nonlinearities in neuronal transfer functions areeschewed by strong synaptic interactions within each point. Consequently, thesimultaneous activation of multiple points results in a linear summation of their respectiveoutputs. We also consider the effects of reduction of inhibition at a cortical point when oneor more surrounding points are active. The network response in this condition is linear overan approximately two to three fold decrease of inhibitory feedback strength. This resultsupports the idea that focal disinhibition allows linear coupling of motor cortical points togenerate movement related muscle activation patterns; albeit with a limitation on gaincontrol. The model also explains why neural activity does not spread as far out as the axonalconnectivity allows, whilst also explaining why distant cortical points can be, nonetheless,functionally coupled by focal disinhibition. Finally, we discuss the advantages that linearinteractions at the cortical level afford to motor command synthesis.

  11. Efficiency Improvement of a High Dynamic BLDC Linear Motor by Multiphase Control

    OpenAIRE

    Lemmens, Joris; Vanvlasselaer, Kris; Mulier, Kristof; Goossens, Stijn; Symens, Wim; Driesen, Johan

    2013-01-01

    This paper proposes a multiphase control strategy for a high dynamic brushless DC linear motor as an alternative for conventional three-phase field-oriented control. Analysis of the magnetic field waveforms shows that three-phase control is not optimal for the 6-slot 7-pole motor topology. Therefore, a multiphase control strategy is elaborated which injects currents proportional to the electromotive force into each of the nine stator coil groups. This results in a maximal alignment force ...

  12. Computation of magnetic field in DC brushless linear motors built with NdFeB magnets

    International Nuclear Information System (INIS)

    Basak, A.; Shirkoohi, G.H.

    1990-01-01

    A software package based on finite element technique has been used to compute three-dimensional magnetic fields and static forces developed in brushless d.c. linear motors. As the field flux-source two different types of permanent magnets, one of them being the high energy neodymium- iron-boron type, has been used in computer models. Motors with the same specifications as the computer models were built and experimental results obtained from them are compared with the computed results

  13. A novel tubular linear motor equipped with radially anisotropic NdFeB ring magnets

    International Nuclear Information System (INIS)

    Hor, P.J.

    1998-01-01

    The paper describes the design synthesis and optimisation of a novel tubular linear motor employing radially magnetised anisotropic ring magnets. Design issues, related to optimising the dimensions for maximum acceleration capability, minimum cogging force and low harmonic distortion in the emf waveform, are discussed. The influence of inhomogeneities in the magnets on the performance of a prototype motor is discussed, and its dynamic performance is validated experimentally against a typical target specification for automated high-speed manufacturing applications. (orig.)

  14. Linear switched reluctance motor control with PIC18F452 microcontroller

    OpenAIRE

    DURSUN, Mahir; KOÇ, Fatmagül

    2014-01-01

    This paper presents the simulation, control, and experimental results of the velocity of a double-sided, 6/4-poled, 3-phased, 8 A, 24 V, 250 W, and 250 N pull force linear switched reluctance motor (LSRM). In the simulation and experimental study, the reference velocity is constant depending on the position and time. The velocity versus the position of the translator was controlled with fuzzy logic control (FLC) and proportional-integral (PI) control techniques. The motor was control...

  15. Numerical studies on the force characteristic of superconducting linear synchronous motor with HTS bulk magnet

    Science.gov (United States)

    Tang, Junjie; Li, Jing; Li, Xiang; Han, Le

    2018-03-01

    High temperature superconductor (HTS) bulks have significant potential use in linear motor application act as quasi-permanent magnet to replace traditional magnets. Force characteristic between HTS bulk magnet and traveling magnetic field was investigated with numerical simulation and experimental measurement in this paper. Influences of bulk height and number on the force characteristic were studied by the finite element model considering the nonlinear E-J relationship. Study was also made on addition of a back iron plate to the bulk magnet. Besides, force characteristic of bulk was compared with the permanent magnet results. The small initial decrease of the thrust could be explained by inside superconducting current redistribution. It was found that efficiency of linear motor did not increase by adding more bulk magnets. The bulk magnet will be remagnetized instead of erasing trapped field with the increase of the traveling magnetic field strength. The conclusions are helpful in prediction and design the linear motor with HTS bulk magnet.

  16. Analysis and Design of Double-sided Air core Linear Servo Motor with Trapezoidal Permanent Magnets

    DEFF Research Database (Denmark)

    Zhang, Yuqiu; Yang, Zilong; Yu, Minghu

    2011-01-01

    In order to reduce the thrust ripple of linear servo system, a double-sided air core permanent magnet linear servo motor with trapezoidal shape permanent magnets (TDAPMLSM) is proposed in this paper. An analytical model of the motor for predicting the magnetic field in the air-gap at no......-load is introduced. This model is derived based on the equivalent magnetization intensity method, and its accuracy is validated by using the results obtained from the finite-element method. The key dimensions that affect the air-gap magnetic field are analyzed based on the analytical model, and the design...

  17. Apparatus and method to pulverize rock using a superconducting electromagnetic linear motor

    Science.gov (United States)

    Ignatiev, Alex (Inventor)

    2009-01-01

    A rock pulverizer device based on a superconducting linear motor. The superconducting electromagnetic rock pulverizer accelerates a projectile via a superconducting linear motor and directs the projectile at high speed toward a rock structure that is to be pulverized by collision of the speeding projectile with the rock structure. The rock pulverizer is comprised of a trapped field superconducting secondary magnet mounted on a movable car following a track, a wire wound series of primary magnets mounted on the track, and the complete magnet/track system mounted on a vehicle used for movement of the pulverizer through a mine as well as for momentum transfer during launch of the rock breaking projectile.

  18. Investigation and Calculation of Magnetic Field in Tubular Linear Reluctance Motor Using FEM

    Directory of Open Access Journals (Sweden)

    MOSALLANEJAD, A.

    2010-11-01

    Full Text Available In this paper the magnetic flux density of tubular linear reluctance motor (TLRM in open type magnetic circuit is studied. Also, all magnetic flux density calculation methods in winding of tubular linear reluctance motor are described. The effect of structure parameters on magnetic flux density is also discussed. Electromagnetic finite-element analysis is used for simulation of magnetic field, and simulation results of the magnetic field analysis with DC voltage excitation are compared with results obtained from calculation methods. The comparison yields a good agreement.

  19. Force Profiles of a Linear Switched Reluctance Motor Having Special Pole Face Shapes

    Directory of Open Access Journals (Sweden)

    CHADRESEKAR, V.

    2010-11-01

    Full Text Available In this paper, the results of a finite element analysis are carried out on an new stator geometry of a three phase longitudinal flux Linear Switched Reluctance Motor (LSRM. In the new geometry, pole shoes are affixed to the stator poles. Static and dynamic characteristics for the proposed structure have been highlighted. Motor performance for variable load conditions is discussed. Frequency spectrum analyses of force profile using the fast Fourier transform (FFT are described to predict the vibration frequencies. The 2-Dimensional (2-D finite element analysis (FEA and the experimental results of this paper prove that LSRMs are one of the strong candidates for linear propulsion drives.

  20. Force prediction in permanent magnet flat linear motors (abstract)

    International Nuclear Information System (INIS)

    Eastham, J.F.; Akmese, R.

    1991-01-01

    The advent of neodymium iron boron rare-earth permanent magnet material has afforded the opportunity to construct linear machines of high force to weight ratio. The paper describes the design and construction of an axial flux machine and rotating drum test rig. The machine occupies an arc of 45 degree on a drum 1.22 m in diameter. The excitation is provided by blocks of NdFeB material which are skewed in order to minimize the force variations due to slotting. The stator carries a three-phase short-chorded double-layer winding of four poles. The machine is supplied by a PWM inverter the fundamental component of which is phase locked to the rotor position so that a ''dc brushless'' drive system is produced. Electromagnetic forces including ripple forces are measured at supply frequencies up to 100 Hz. They are compared with finite-element analysis which calculates the force variation over the time period. The paper then considers some of the causes of ripple torque. In particular, the force production due solely to the permanent magnet excitation is considered. This has two important components each acting along the line of motion of the machine, one is due to slotting and the other is due to the finite length of the primary. In the practical machine the excitation poles are skewed to minimize the slotting force and the effectiveness of this is confirmed by both results from the experiments and the finite-element analysis. The end effect force is shown to have a space period of twice that of the excitation. The amplitude of this force and its period are again confirmed by practical results

  1. Modeling and experimental validation of a linear ultrasonic motor considering rough surface contact

    Science.gov (United States)

    Lv, Qibao; Yao, Zhiyuan; Li, Xiang

    2017-04-01

    Linear ultrasonic motor is driven by the interface friction between the stator and the slider. The performance of the motor is significantly affected by the contact state between the stator and slider which depends considerably on the morphology of the contact interface. A novel fiction model is developed to evaluate the output characteristics of a linear ultrasonic motor. The proposed model, where the roughness and plastic deformation of contact surfaces are considered, differs from the previous spring model. Based on the developed model, the effects of surface roughness parameters on motor performance are investigated. The behavior of the force transmission between the stator and the slider is studied to understand the driving mechanism. Furthermore, a comparison between the proposed model and the spring model is made. An experiment is designed to verify the feasibility and effectiveness of this proposed model by comparing the simulation results with the measured one. The results show that the proposed model is more accurate than the spring model. These discussions will be very useful for the improvement of control and the optimal design of linear ultrasonic motor.

  2. Thrust Reduction of Magnetic Levitation Vehicle Driven by Long Stator Linear Synchronous Motor

    Directory of Open Access Journals (Sweden)

    Wan-Tsun Tseng

    2013-01-01

    Full Text Available The propulsion technology of long stator linear synchronous motors is used to drive high-speed maglev trains. The linear synchronous motor stator is divided into sections placed on guideway. The electric power supplies to stator sections in which the train just passes in change-step mode for long-distance operation. However, a thrust drop will be caused by change-step machinery for driving magnetic vehicle. According to the train speed and vehicle data, the change-step mode has three types of operation, namely premature commutation, simultaneous commutation, and late commutation. Each type of operation has a different thrust drop which can be affected by several parameters such as jerk, running speed, motor section length, and vehicle data. This paper focuses on determining the thrust drop of the change-step mode. The study results of this paper can be used to improve the operation system of high-speed maglev trains.

  3. A speed estimation unit for induction motors based on adaptive linear combiner

    International Nuclear Information System (INIS)

    Marei, Mostafa I.; Shaaban, Mostafa F.; El-Sattar, Ahmed A.

    2009-01-01

    This paper presents a new induction motor speed estimation technique, which can estimate the rotor resistance as well, from the measured voltage and current signals. Moreover, the paper utilizes a novel adaptive linear combiner (ADALINE) structure for speed and rotor resistance estimations. This structure can deal with the multi-output systems and it is called MO-ADALINE. The model of the induction motor is arranged in a linear form, in the stationary reference frame, to cope with the proposed speed estimator. There are many advantages of the proposed unit such as wide speed range capability, immunity against harmonics of measured waveforms, and precise estimation of the speed and the rotor resistance at different dynamic changes. Different types of induction motor drive systems are used to evaluate the dynamic performance and to examine the accuracy of the proposed unit for speed and rotor resistance estimation.

  4. Linear Motor Motion Control Experiment System Design Based on LabVIEW

    Directory of Open Access Journals (Sweden)

    Cuixian He

    2018-01-01

    Full Text Available In order to meet the needs of experimental training of electrical information industry, a linear motor motion experiment system based on LabVIEW was developed. This system is based on the STM32F103ZET6 system processor controller, a state signal when the motor moves through the grating encoder feedback controller to form a closed loop, through the RS232 serial port communication with the host computer, the host computer is designed in the LabVIEW interactive environment monitoring software. Combined with the modular design concept proposed overall program, given the detailed hardware circuit, targeted for the software function design, to achieve man-machine interface. The system control of high accuracy, good stability, meet the training requirements for laboratory equipment, but also as a reference embodiment of the linear motor monitoring system.

  5. Comparison of Thrust Characteristics in Pencil Sized Cylinder-type Linear Motors with Different Magnet Arrays

    OpenAIRE

    Nakaiwa, K; Yamada, A; Tashiro, K; Wakiwaka, H

    2009-01-01

    From a strong demand on the miniaturization of a chip mounter or a semiconductor device, the thrust improvement considering the magnets arrangement is studied. We accept a core stator with a Halbach type magnet array for a current linear motor. The thrust characteristics are compared with two kinds of mover, a NS magnet array and a Halbach magnet array.

  6. Performance improvement of rectangular-plate linear ultrasonic motors using dual-frequency drive.

    Science.gov (United States)

    Ming, Yang; Richardson, Robert C; Levesley, Martin C; Walker, Peter G; Watterson, Kevin

    2004-12-01

    To improve the performances of a rectangular-plate linear ultrasonic motor for specific applications, a dual-frequency drive has been proposed and investigated. Through careful design of the rectangular piezoelectric ceramic plate, its first longitudinal resonant frequency coincides with its second lateral bending resonant frequency and is one-third of its higher lateral bending resonant frequency. When a square-wave voltage is used to drive the motor, its first longitudinal and second bending and the higher bending vibration modes are excited. Experimental results show that the maximum thrust force and maximum velocity of the motor are over 170% of those obtained from the single-frequency sine-wave drive when the voltage performance of the motor becomes saturated.

  7. Application of Quadratic Linearization for the Control of Permanent Magnet Synchronous Motor

    Directory of Open Access Journals (Sweden)

    Parvathy Ayalur Krishnamoorthy

    2011-01-01

    Full Text Available Many of the existing control methods for the permanent magnet synchronous motor (PMSM either deal with steady state models or consider dynamic models under particular cases. A dynamic model of the PM machine allows powerful control-theoretic techniques such as linearization to be applied to the system. Existing exact feedback linearization of dynamic model of PMSM suffers from singularity issues. In this paper, we propose a quadratic linearization approach for PMSM based on the approximate linearization technique which does not introduce singularities. A MATLAB simulation is used to verify the effectiveness of the linearization technique proposed. Also, to account for higher-order and unmodelled dynamics of PMSM, tuning of the linearizing transformation is proposed and verified using simulation.

  8. Design and testing of a coaxial linear magnetic spring with integral linear motor. [for spacecraft energy storage

    Science.gov (United States)

    Patt, P. J.

    1985-01-01

    The design of a coaxial linear magnetic spring which incorporates a linear motor to control axial motion and overcome system damping is presented, and the results of static and dynamic tests are reported. The system has nominal stiffness 25,000 N/m and is designed to oscillate a 900-g component over a 4.6-mm stroke in a Stirling-cycle cryogenic refrigerator being developed for long-service (5-10-yr) space applications (Stolfi et al., 1983). Mosaics of 10 radially magnetized high-coercivity SmCO5 segments enclosed in Ti cans are employed, and the device is found to have quality factor 70-100, corresponding to energy-storage efficiency 91-94 percent. Drawings, diagrams, and graphs are provided.

  9. Universal linear motor driven Leg Press Dynamometer and concept of Serial Stretch Loading

    Directory of Open Access Journals (Sweden)

    Dušan Hamar

    2015-08-01

    Full Text Available Paper deals with backgrounds and principles of universal linear motor driven leg press dynamometer and concept of serial stretch loading. The device is based on two computer controlled linear motors mounted to the horizontal rails. As the motors can keep either constant resistance force in selected position or velocity in both directions, the system allows simulation of any mode of muscle contraction. In addition, it also can generate defined serial stretch stimuli in a form of repeated force peaks. This is achieved by short segments of reversed velocity (in concentric phase or acceleration (in eccentric phase. Such stimuli, generated at the rate of 10 Hz, have proven to be a more efficient means for the improvement of rate of the force development. This capability not only affects performance in many sports, but also plays a substantial role in prevention of falls and their consequences. Universal linear motor driven and computer controlled dynamometer with its unique feature to generate serial stretch stimuli seems to be an efficient and useful tool for enhancing strength training effects on neuromuscular function not only in athletes, but as well as in senior population and rehabilitation patients.

  10. A superconducting linear motor drive for a positive displacement bellows pump for use in the g-2 cryogenics system

    International Nuclear Information System (INIS)

    Green, M.A.

    1994-10-01

    Forced two-phase cooling of indirectly cooled magnets requires circulation of liquid helium through the magnet cooling channel. A bellows helium pump is one possible way of providing helium flow to a magnet cooling system. Since the bellows type of helium pump is immersed in liquid helium, a superconducting linear motor drive appears to be an attractive option. This report describes a linear motor drive that employs oriented permanent magnet materials such as samarium-cobalt as the stator magnet system and a superconducting loud speaker voice coil type of drive as the armature of the linear motor. This report examines drive motor requirements for a helium pump

  11. Contact and Non-contact Measurements of Grinding Pins

    Directory of Open Access Journals (Sweden)

    Magdziak Marek

    2015-01-01

    Full Text Available The paper presents the results of contact and non-contact measurements of external profiles of selected grinding pins. The measurements were conducted in order to choose the appropriate measuring technique in the case of the considered measurement task. In the case of contact measurements the coordinate measuring machine ACCURA II was applied. The used coordinate measuring machine was equipped with the contact scanning probe VAST XT and the Calypso inspection software. Contact coordinate measurements were performed by using of different measurement strategies. The applied strategies included different scanning velocities and distances between measured points. Non-contact measurements were conducted by means of the tool presetter produced by the Mahr company. On the basis of gained results the guidelines concerning measurements of grinding pins were formulated. The measurements of analyzed grinding pins performed by means of the non-contact measuring system are characterized by higher reproducibility than the contact measurements. The low reproducibility of contact measurements may be connected with the inaccuracy of the selected coordinate measuring machine and the measuring probe, the measurement parameters and environmental conditions in the laboratory where the coordinate measuring machine is located. Moreover, the paper presents the possible application of results of conducted investigations. The results of non-contact measurements can be used in the simulation studies of grinding processes. The simulations may reduce the costs of machining processes.

  12. Continuous control systems for non-contact ECG

    Science.gov (United States)

    Kodkin, Vladimir L.; Yakovleva, Galina V.; Smirnov, Alexey S.

    2017-03-01

    South Ural State University is still conducting the research work dedicated to innovations in biomedicine. Development of system for continuous control and diagnosis of the functional state in large groups of people is based on studies of non-contact ECG recording reported by the authors at the SPIE conference in 2016. The next stage of studies has been performed this year.

  13. Application of an imperialist competitive algorithm to the design of a linear induction motor

    International Nuclear Information System (INIS)

    Lucas, Caro; Nasiri-Gheidari, Zahra; Tootoonchian, Farid

    2010-01-01

    In this paper a novel optimization algorithm based on imperialist competitive algorithm (ICA) is used for the design of a low speed single sided linear induction motor (LIM). This type of motors is used increasingly in industrial process specially in transportation systems. In these applications having high efficiency with high power factor is very important. So in this paper the objective function of design is presented considering both efficiency and power factor. Finally the results of ICA are compared with the ones of genetic algorithm and conventional design. Comparison shows the success of ICA for design of LIMs.

  14. Torque ripple reduction of brushless DC motor based on adaptive input-output feedback linearization.

    Science.gov (United States)

    Shirvani Boroujeni, M; Markadeh, G R Arab; Soltani, J

    2017-09-01

    Torque ripple reduction of Brushless DC Motors (BLDCs) is an interesting subject in variable speed AC drives. In this paper at first, a mathematical expression for torque ripple harmonics is obtained. Then for a non-ideal BLDC motor with known harmonic contents of back-EMF, calculation of desired reference current amplitudes, which are required to eliminate some selected harmonics of torque ripple, are reviewed. In order to inject the reference harmonic currents to the motor windings, an Adaptive Input-Output Feedback Linearization (AIOFBL) control is proposed, which generates the reference voltages for three phases voltage source inverter in stationary reference frame. Experimental results are presented to show the capability and validity of the proposed control method and are compared with the vector control in Multi-Reference Frame (MRF) and Pseudo-Vector Control (P-VC) method results. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  15. A high-power linear ultrasonic motor using longitudinal vibration transducers with single foot.

    Science.gov (United States)

    Liu, Yingxiang; Chen, Weishan; Liu, Junkao; Shi, Shengjun

    2010-08-01

    A high-power linear ultrasonic motor using longitudinal vibration transducers with single foot was proposed in this paper. The stator of proposed motor contains a horizontal transducer and a vertical transducer. Longitudinal vibrations are superimposed in the stator and generate an elliptical trajectory at the driving foot. The sensitivity analysis of structural parameters to the resonance frequencies of two working modes of the stator was performed using the finite element method. The resonance frequencies of two working modes were degenerated by adjusting the structural parameters. The vibration characteristics of stator were studied and discussed. A prototype motor was fabricated and measured. Typical output of the prototype is a no-load speed of 1160 mm/s and maximum thrust force of 20 N at a voltage of 200 V(rms).

  16. Linear magnetic motor/generator. [to generate electric energy using magnetic flux for spacecraft power supply

    Science.gov (United States)

    Studer, P. A. (Inventor)

    1982-01-01

    A linear magnetic motor/generator is disclosed which uses magnetic flux to provide mechanical motion or electrical energy. The linear magnetic motor/generator includes an axially movable actuator mechanism. A permament magnet mechanism defines a first magnetic flux path which passes through a first end portion of the actuator mechanism. Another permament magnet mechanism defines a second magnetic flux path which passes through a second end portion of the actuator mechanism. A drive coil defines a third magnetic flux path passing through a third central portion of the actuator mechanism. A drive coil selectively adds magnetic flux to and subtracts magnetic flux from magnetic flux flowing in the first and second magnetic flux path.

  17. A new direct torque control scheme for induction motors using linear state feedback

    Energy Technology Data Exchange (ETDEWEB)

    Kandianis, A.; Manias, S.N. [National Technical Univ. of Athens (Greece). Dept. of Electrical Engineering; Griva, G.; Profumo, F. [Politecnico di Torino (Italy). Dept. of Electrical Engineering

    1995-12-31

    In this paper a new Direct Torque Control (DTC) scheme for induction motor drives is described, based on the linear state feedback method with dynamic output feedback. The DTC has been shown to be a good solution in torque controlled drives applications when the speed control is not required (e.g. traction drives for electric vehicles). In such cases, the torque command comes directly from the user input. By considering the torque and flux as the outputs of the linearized motor model, it is possible to design an optimum controller with constant gain state feedback and dynamic output feedback through an integral term. The design procedure of the proposed control scheme is described and the simulation results are presented to show the overall performance of the system.

  18. Position Control of Linear Synchronous Motor Drives with Exploitation of Forced Dynamics Control Principles

    Directory of Open Access Journals (Sweden)

    Jan Vittek

    2004-01-01

    Full Text Available Closed-loop position control of mechanisms directly driven by linear synchronous motors with permanent magnets is presented. The control strategy is based on forced dynamic control, which is a form of feedback linearisation, yielding a non-liner multivariable control law to obtain a prescribed linear speed dynamics together with the vector control condition of mutal orthogonality between the stator current and magnetic flux vectors (assuming perfect estimates of the plant parameters. Outer position control loop is closed via simple feedback with proportional gain. Simulations of the design control sysstem, including the drive with power electronic switching, predict the intended drive performance.

  19. Experimental Manufacture and Performance Evaluation of Linear Switched Reluctance Motor with HTS Excitation Windings

    Science.gov (United States)

    Hirayama, Tadashi; Oto, Satoshi; Higashijima, Atsushi; Kawabata, Shuma

    This paper presents an experimental manufacture and performance evaluation of prototype linear switched reluctance motor with HTS excitation windings (HTS-LSRM). The Ag-alloy sheathed Bi-2223 tapes are used for HTS coils. We first present a structure of the prototype HTS-LSRM. Next, current-carrying properties of the HTS coils are measured. Furthermore, current and voltage waveforms are measured and we evaluation a control performance of the current and voltage.

  20. Electrohydraulic linear actuator with two stepping motors controlled by overshoot-free algorithm

    Science.gov (United States)

    Milecki, Andrzej; Ortmann, Jarosław

    2017-11-01

    The paper describes electrohydraulic spool valves with stepping motors used as electromechanical transducers. A new concept of a proportional valve in which two stepping motors are working differentially is introduced. Such valve changes the fluid flow proportionally to the sum or difference of the motors' steps numbers. The valve design and principle of its operation is described. Theoretical equations and simulation models are proposed for all elements of the drive, i.e., the stepping motor units, hydraulic valve and cylinder. The main features of the valve and drive operation are described; some specific problem areas covering the nature of stepping motors and their differential work in the valve are also considered. The whole servo drive non-linear model is proposed and used further for simulation investigations. The initial simulation investigations of the drive with a new valve have shown that there is a significant overshoot in the drive step response, which is not allowed in positioning process. Therefore additional effort is spent to reduce the overshoot and in consequence reduce the settling time. A special predictive algorithm is proposed to this end. Then the proposed control method is tested and further improved in simulations. Further on, the model is implemented in reality and the whole servo drive system is tested. The investigation results presented in this paper, are showing an overshoot-free positioning process which enables high positioning accuracy.

  1. Influence of a high vacuum on the precise positioning using an ultrasonic linear motor.

    Science.gov (United States)

    Kim, Wan-Soo; Lee, Dong-Jin; Lee, Sun-Kyu

    2011-01-01

    This paper presents an investigation of the ultrasonic linear motor stage for use in a high vacuum environment. The slider table is driven by the hybrid bolt-clamped Langevin-type ultrasonic linear motor, which is excited with its different modes of natural frequencies in both lateral and longitudinal directions. In general, the friction behavior in a vacuum environment becomes different from that in an environment of atmospheric pressure and this difference significantly affects the performance of the ultrasonic linear motor. In this paper, to consistently provide stable and high power of output in a high vacuum, frequency matching was conducted. Moreover, to achieve the fine control performance in the vacuum environment, a modified nominal characteristic trajectory following control method was adopted. Finally, the stage was operated under high vacuum condition, and the operating performances were investigated compared with that of a conventional PI compensator. As a result, robustness of positioning was accomplished in a high vacuum condition with nanometer-level accuracy.

  2. Numerical calculation of primary slot leakage inductance of a Single-sided HTS linear induction motor used for linear metro

    Science.gov (United States)

    Li, Dong; Wen, Yinghong; Li, Weili; Fang, Jin; Cao, Junci; Zhang, Xiaochen; Lv, Gang

    2017-03-01

    In the paper, the numerical method calculating asymmetric primary slot leakage inductances of Single-sided High-Temperature Superconducting (HTS) Linear Induction Motor (HTS LIM) is presented. The mathematical and geometric models of three-dimensional nonlinear transient electromagnetic field are established and the boundary conditions are also given. The established model is solved by time-stepping Finite Element Method (FEM). Then, the three-phase asymmetric primary slot leakage inductances under different operation conditions are calculated by using the obtained electromagnetic field distribution. The influences of the special effects such as longitudinal end effects, transversal edge effects, etc. on the primary slot leakage inductance are investigated. The presented numerical method is validated by experiments carried out on a 3.5 kW prototype with copper wires which has the same structures with the HTS LIM.

  3. A non-contact time-domain scanning brain imaging system: first in-vivo results

    Science.gov (United States)

    Mazurenka, M.; Di Sieno, L.; Boso, G.; Contini, D.; Pifferi, A.; Dalla Mora, A.; Tosi, A.; Wabnitz, H.; Macdonald, R.

    2013-06-01

    We present results of first in-vivo tests of an optical non-contact scanning imaging system, intended to study oxidative metabolism related processes in biological tissue by means of time-resolved near-infrared spectroscopy. Our method is a novel realization of the short source-detector separation approach and based on a fast-gated single-photon avalanche diode to detect late photons only. The scanning system is built in quasi-confocal configuration and utilizes polarizationsensitive detection. It scans an area of 4×4 cm2, recording images with 32×32 pixels, thus creating a high density of source-detector pairs. To test the system we performed a range of in vivo measurements of hemodynamic changes in several types of biological tissues, i.e. skin (Valsalva maneuver), muscle (venous and arterial occlusions) and brain (motor and cognitive tasks). Task-related changes in hemoglobin concentrations were clearly detected in skin and muscle. The brain activation shows weaker, but yet detectable changes. These changes were localized in pixels near the motor cortex area (C3). However, it was found that even very short hair substantially impairs the measurement. Thus the applicability of the scanner is limited to hairless parts of body. The results of our first in-vivo tests prove the feasibility of non-contact scanning imaging as a first step towards development of a prototype for biological tissue imaging for various medical applications.

  4. Optimization of a one-frequency-two-mode traveling-wave piezoelectric linear motor by electrode design

    Science.gov (United States)

    Wu, Sheng-Hsun; Li, Chia-Chin; Chen, Tsun-Hsu; Hsu, Yu-Hsiang; Wu, Wen-Jong; Lee, Chih-Kung

    2017-04-01

    Piezoelectric motor is based on generating traveling waves on a finite structure. It can be classified into linear and rotary types. Among them, linear motors have an inevitable problem since finite boundaries are always exist, and reflected waves can hinder the formation of propagating waves. To solve this problem, a linear motor based on a single driving frequency and two induced resonant molds are previously reported. However, the driving frequencies are not at structure resonant frequency, the efficiency of linear motor is based on the superposition of two adjacent bending modes. The traveling wave is created by two piezoelectric actuators driven by a single frequency in between these two resonant molds with a 90° phase difference. Based on previous report, it shows that by placing these two 0.178/L length actuators at 0.22/L and 0.78/L on a one-dimensional beam with length L, an optimal performance could be reached. It suggested that the location and size of the two piezoelectric actuators can be used to optimize the performance of the linear motor. In this study, finite element simulation was used to study the contributions of the temporal and spatial correlations between the two actuators with respect to a 1-D linear motor. The position and size of these two piezoelectric actuators are studied for optimizing the performance of the linear motor.

  5. Non-contact fluid characterization in containers using ultrasonic waves

    Science.gov (United States)

    Sinha, Dipen N [Los Alamos, NM

    2012-05-15

    Apparatus and method for non-contact (stand-off) ultrasonic determination of certain characteristics of fluids in containers or pipes are described. A combination of swept frequency acoustic interferometry (SFAI), wide-bandwidth, air-coupled acoustic transducers, narrowband frequency data acquisition, and data conversion from the frequency domain to the time domain, if required, permits meaningful information to be extracted from such fluids.

  6. Non-contacting "snubber bearing" for passive magnetic bearing systems

    Science.gov (United States)

    Post, Richard F

    2017-08-22

    A new non-contacting magnetic "snubber" bearing is provided for application to rotating systems such as vehicular electromechanical battery systems subject to frequent accelerations. The design is such that in the equilibrium position the drag force of the snubber is very small (milliwatts). However in a typical case, if the rotor is displaced by as little as 2 millimeters a large restoring force is generated without any physical contact between the stationary and rotating parts of the snubber bearing.

  7. CONFIRMATION OF THE MATHEMATICAL MODEL ADEQUACY OF A LINEAR SYNCHRONOUS MOTOR

    Directory of Open Access Journals (Sweden)

    V. F. Novikov

    2015-06-01

    Full Text Available Purpose.To reduce labor costs and the amount of computer time in the design of linear synchronous motors with excitation from a source of a constant magnetic field of high-speed ground transportation it is necessary to use engineering methods. The purpose of this study is to confirm the adequacy of the previously proposed mathematical model of this engine and assumptions. It is also intended to confirm the possibility of applying the method of calculation of traction that occurs in the engine in the interaction of the permanent magnetic field of the excitation system of a vehicle with a coil track structure.Methodology. As for empirical theories the positive result of the experiment is not absolute proof of the truth, for an unambiguous conclusion about the adequacy of the developed model and the effectiveness of the developed methods need to be tested for falsification. In accordance with this criterion, it is necessary to conduct an experiment, the results of which will coincide with the calculation but you also need to avoid errors caused by random coincidences. For this purpose the experiments with varying parameters are conducted. Findings. In a critical experiment configuration changes of the excitation system were held so that the shape dependence of traction from displacement is differed significantly. The comparison of the results of the calculated and experimental values of traction for different configurations showed that the differences are minor and easily explained by measurement error and uneven gaps between the poles and excitation coils of the track structure. Originality. The adequacy of the mathematical model of a linear synchronous motor without a ferromagnetic magnetic circuit and the assumptions and applicability of the calculation method of traction forces involved in it, at the interaction of a permanent magnetic field of the excitation system of a vehicle with a coil track structure were proved. This proof is built on

  8. Bond Graph Modelling for Fault Detection and Isolation of an Ultrasonic Linear Motor

    Directory of Open Access Journals (Sweden)

    Mabrouk KHEMLICHE

    2010-12-01

    Full Text Available In this paper Bond Graph modeling, simulation and monitoring of ultrasonic linear motors are presented. Only the vibration of piezoelectric ceramics and stator will be taken into account. Contact problems between stator and rotor are not treated here. So, standing and travelling waves will be briefly presented since the majority of the motors use another wave type to generate the stator vibration and thus obtain the elliptic trajectory of the points on the surface of the stator in the first time. Then, electric equivalent circuit will be presented with the aim for giving a general idea of another way of graphical modelling of the vibrator introduced and developed. The simulations of an ultrasonic linear motor are then performed and experimental results on a prototype built at the laboratory are presented. Finally, validation of the Bond Graph method for modelling is carried out, comparing both simulation and experiment results. This paper describes the application of the FDI approach to an electrical system. We demonstrate the FDI effectiveness with real data collected from our automotive test. We introduce the analysis of the problem involved in the faults localization in this process. We propose a method of fault detection applied to the diagnosis and to determine the gravity of a detected fault. We show the possibilities of application of the new approaches to the complex system control.

  9. Optimization and Analysis of a U-Shaped Linear Piezoelectric Ultrasonic Motor Using Longitudinal Transducers

    Directory of Open Access Journals (Sweden)

    Hongpeng Yu

    2018-03-01

    Full Text Available A novel U-shaped piezoelectric ultrasonic motor that mainly focused on miniaturization and high power density was proposed, fabricated, and tested in this work. The longitudinal vibrations of the transducers were excited to form the elliptical movements on the driving feet. Finite element method (FEM was used for design and analysis. The resonance frequencies of the selected vibration modes were tuned to be very close to each other with modal analysis and the movement trajectories of the driving feet were gained with transient simulation. The vibration modes and the mechanical output abilities were tested to evaluate the proposed motor further by a prototype. The maximum output speed was tested to be 416 mm/s, the maximum thrust force was 21 N, and the maximum output power was 5.453 W under frequency of 29.52 kHz and voltage of 100 Vrms. The maximum output power density of the prototype reached 7.59 W/kg, which was even greater than a previous similar motor under the exciting voltage of 200 Vrms. The proposed motor showed great potential for linear driving of large thrust force and high power density.

  10. Adaptive H∞ nonlinear velocity tracking using RBFNN for linear DC brushless motor

    Science.gov (United States)

    Tsai, Ching-Chih; Chan, Cheng-Kain; Li, Yi Yu

    2012-01-01

    This article presents an adaptive H ∞ nonlinear velocity control for a linear DC brushless motor. A simplified model of this motor with friction is briefly recalled. The friction dynamics is described by the Lu Gre model and the online tuning radial basis function neural network (RBFNN) is used to parameterise the nonlinear friction function and un-modelled errors. An adaptive nonlinear H ∞ control method is then proposed to achieve velocity tracking, by assuming that the upper bounds of the ripple force, the changeable load and the nonlinear friction can be learned by the RBFNN. The closed-loop system is proven to be uniformly bounded using the Lyapunov stability theory. The feasibility and the efficacy of the proposed control are exemplified by conducting two velocity tracking experiments.

  11. A linear motor and compact cylinder-piston driver for left ventricular bypass.

    Science.gov (United States)

    Qian, K X

    1990-01-01

    A simple, portable, reliable and noise-free pneumatic driver has been developed. It consists of a linear motor attached to a cylinder piston, in one unit. The motor coil is directly wound on the cylinder, and the permanent magnet is fixed to the piston. As a continuous voltage square wave is applied to the coil, the cylinder reciprocates on the piston periodically, producing air pressure and vacuum alternately. In conjunction with a locally made diaphragm pump, the driver was tested in vitro and in vivo. Results demonstrated that the device could drive the diaphragm pump and so support the circulation of an experimental animal. The driver weighs 12 kg. For 200 mmHg air pressure and -80 mmHg vacuum the power consumed is 30 W. Its noise is about 30 dB, less than that of an artificial valve and pump.

  12. Simulation of magnetic induction distribution in a coaxial linear motor with axial and radial direction of permanent magnets magnetization

    Directory of Open Access Journals (Sweden)

    G.M. Golenkov

    2014-03-01

    Full Text Available The paper presents results of computer simulation and experimental study of magnetic induction distribution in a coaxial linear motor air gap throughout the length of the runner active part at different heights of the air gap between the runner and the inductor magnetic core for motors with axial and radial direction of the permanent magnets magnetization.

  13. Microwave non-contact imaging of subcutaneous human body tissues

    Science.gov (United States)

    Chernokalov, Alexander; Khripkov, Alexander; Cho, Jaegeol; Druchinin, Sergey

    2015-01-01

    A small-size microwave sensor is developed for non-contact imaging of a human body structure in 2D, enabling fitness and health monitoring using mobile devices. A method for human body tissue structure imaging is developed and experimentally validated. Subcutaneous fat tissue reconstruction depth of up to 70 mm and maximum fat thickness measurement error below 2 mm are demonstrated by measurements with a human body phantom and human subjects. Electrically small antennas are developed for integration of the microwave sensor into a mobile device. Usability of the developed microwave sensor for fitness applications, healthcare, and body weight management is demonstrated. PMID:26609415

  14. Algorithm describing pressure distribution of non-contact TNT explosion

    Directory of Open Access Journals (Sweden)

    Radosław Kiciński

    2014-12-01

    Full Text Available [b]Abstract[/b]. The aim of this study is to develop a computational algorithm, describing the shock wave pressure distribution in the space induced by non-contact TNT explosion. The procedure describes pressure distribution on a damp surface of the hull. Simulations have been carried out using Abaqus/CAE. The study also shows the pressure waveform descriptions provided by various authors and presents them in charts. The formulated conclusions convince efficiency of the algorithm application.[b]Keywords:[/b] Underwater explosion, shock wave, CAE, TNT, Kobben class submarine

  15. Microwave non-contact imaging of subcutaneous human body tissues.

    Science.gov (United States)

    Kletsov, Andrey; Chernokalov, Alexander; Khripkov, Alexander; Cho, Jaegeol; Druchinin, Sergey

    2015-10-01

    A small-size microwave sensor is developed for non-contact imaging of a human body structure in 2D, enabling fitness and health monitoring using mobile devices. A method for human body tissue structure imaging is developed and experimentally validated. Subcutaneous fat tissue reconstruction depth of up to 70 mm and maximum fat thickness measurement error below 2 mm are demonstrated by measurements with a human body phantom and human subjects. Electrically small antennas are developed for integration of the microwave sensor into a mobile device. Usability of the developed microwave sensor for fitness applications, healthcare, and body weight management is demonstrated.

  16. Non-Contact Cardiac Activity Monitoring using Pulsed Laser Vibrometer

    Directory of Open Access Journals (Sweden)

    Chen Chia WANG

    2014-01-01

    Full Text Available We demonstrate experimentally the detection of detailed human cardiac mechanical activity in a remote, non-contacting, and non-ionizing manner using a pulsed laser vibrometer. The highly sensitive pulsed laser vibrometer allows the detection of the temporally-phased mechanical events occurring in individual cardiac cycles even from the surface of clothing-covered extremities of the subjects. Fine structures of the detected cardiac traces are identified with their meanings assigned and corroborated using accelerometer and electrocardiogram measurements obtained concurrently with the pulsed laser vibrometer studies.

  17. Decentralized control of the COFS-I Mast using linear dc motors

    Science.gov (United States)

    Lindner, Douglas K.; Celano, Tom; Ide, Eric

    1989-01-01

    Consideration is given to a decentralized control design for vibration suppression in the COFS-I Mast using linear dc motors for actuators. The decentralized control design is based results from power systems using root locus techniques that are not well known. The approach is effective because the loop gain is low due to low actuator authority. The frequency-dependent nonlinearities of the actuator are taken into account. Because of the tendency of the transients to saturate the the stroke length of the actuator, its effectiveness is limited.

  18. Incremental Adaptive Fuzzy Control for Sensorless Stroke Control of A Halbach-type Linear Oscillatory Motor

    Science.gov (United States)

    Lei, Meizhen; Wang, Liqiang

    2018-01-01

    The halbach-type linear oscillatory motor (HT-LOM) is multi-variable, highly coupled, nonlinear and uncertain, and difficult to get a satisfied result by conventional PID control. An incremental adaptive fuzzy controller (IAFC) for stroke tracking was presented, which combined the merits of PID control, the fuzzy inference mechanism and the adaptive algorithm. The integral-operation is added to the conventional fuzzy control algorithm. The fuzzy scale factor can be online tuned according to the load force and stroke command. The simulation results indicate that the proposed control scheme can achieve satisfied stroke tracking performance and is robust with respect to parameter variations and external disturbance.

  19. Particle Swarm Based Approach of a Real-Time Discrete Neural Identifier for Linear Induction Motors

    Directory of Open Access Journals (Sweden)

    Alma Y. Alanis

    2013-01-01

    Full Text Available This paper focusses on a discrete-time neural identifier applied to a linear induction motor (LIM model, whose model is assumed to be unknown. This neural identifier is robust in presence of external and internal uncertainties. The proposed scheme is based on a discrete-time recurrent high-order neural network (RHONN trained with a novel algorithm based on extended Kalman filter (EKF and particle swarm optimization (PSO, using an online series-parallel con…figuration. Real-time results are included in order to illustrate the applicability of the proposed scheme.

  20. Improvement of superconducting cylindrical linear induction motor; Chodendo entokeitan ichiji rinia yudo mota no tokusei kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Kikuma, T.; Tomita, M.; Ishiyama, A. [Waseda Univ., Tokyo (Japan)

    1999-11-10

    For the purpose of we examining the effect of characteristics and ac loss under real machine operating environment of the alternating current superconductivity winding for a realization of the superconductive AC machine vessel, cylindrical shortness first linear guiding motor which used NbTi/CuNi superconducting cable for the primary winding was produced experimentally. The coil number was increased from 6 in 14 this time, and the optimization of the primary current was done, and the improvement on characteristics was attempted. Here, starting torque characteristics, quenching detection protection control circuit are reported. (NEDO)

  1. Non-Contact Conductivity Measurement for Automated Sample Processing Systems

    Science.gov (United States)

    Beegle, Luther W.; Kirby, James P.

    2012-01-01

    A new method has been developed for monitoring and control of automated sample processing and preparation especially focusing on desalting of samples before analytical analysis (described in more detail in Automated Desalting Apparatus, (NPO-45428), NASA Tech Briefs, Vol. 34, No. 8 (August 2010), page 44). The use of non-contact conductivity probes, one at the inlet and one at the outlet of the solid phase sample preparation media, allows monitoring of the process, and acts as a trigger for the start of the next step in the sequence (see figure). At each step of the muti-step process, the system is flushed with low-conductivity water, which sets the system back to an overall low-conductivity state. This measurement then triggers the next stage of sample processing protocols, and greatly minimizes use of consumables. In the case of amino acid sample preparation for desalting, the conductivity measurement will define three key conditions for the sample preparation process. First, when the system is neutralized (low conductivity, by washing with excess de-ionized water); second, when the system is acidified, by washing with a strong acid (high conductivity); and third, when the system is at a basic condition of high pH (high conductivity). Taken together, this non-contact conductivity measurement for monitoring sample preparation will not only facilitate automation of the sample preparation and processing, but will also act as a way to optimize the operational time and use of consumables

  2. Automatic Human Movement Assessment With Switching Linear Dynamic System: Motion Segmentation and Motor Performance.

    Science.gov (United States)

    de Souza Baptista, Roberto; Bo, Antonio P L; Hayashibe, Mitsuhiro

    2017-06-01

    Performance assessment of human movement is critical in diagnosis and motor-control rehabilitation. Recent developments in portable sensor technology enable clinicians to measure spatiotemporal aspects to aid in the neurological assessment. However, the extraction of quantitative information from such measurements is usually done manually through visual inspection. This paper presents a novel framework for automatic human movement assessment that executes segmentation and motor performance parameter extraction in time-series of measurements from a sequence of human movements. We use the elements of a Switching Linear Dynamic System model as building blocks to translate formal definitions and procedures from human movement analysis. Our approach provides a method for users with no expertise in signal processing to create models for movements using labeled dataset and later use it for automatic assessment. We validated our framework on preliminary tests involving six healthy adult subjects that executed common movements in functional tests and rehabilitation exercise sessions, such as sit-to-stand and lateral elevation of the arms and five elderly subjects, two of which with limited mobility, that executed the sit-to-stand movement. The proposed method worked on random motion sequences for the dual purpose of movement segmentation (accuracy of 72%-100%) and motor performance assessment (mean error of 0%-12%).

  3. A new standing-wave-type linear ultrasonic motor based on in-plane modes.

    Science.gov (United States)

    Shi, Yunlai; Zhao, Chunsheng

    2011-05-01

    This paper presents a new standing-wave-type linear ultrasonic motor using combination of the first longitudinal and the second bending modes. Two piezoelectric plates in combination with a metal thin plate are used to construct the stator. The superior point of the stator is its isosceles triangular structure part of the stator, which can amplify the displacement in horizontal direction of the stator in perpendicular direction when the stator is operated in the first longitudinal mode. The influence of the base angle θ of the triangular structure part on the amplitude of the driving foot has been analyzed by numerical analysis. Four prototype stators with different angles θ have been fabricated and the experimental investigation of these stators has validated the numerical simulation. The overall dimensions of the prototype stators are no more than 40 mm (length) × 20 mm (width) × 5 mm (thickness). Driven by an AC signal with the driving frequency of 53.3 kHz, the no-load speed and the maximal thrust of the prototype motor using the stator with base angle 20° were 98 mm/s and 3.2N, respectively. The effective elliptical motion trajectory of the contact point of the stator can be achieved by the isosceles triangular structure part using only two PZTs, and thus it makes the motor low cost in fabrication, simple in structure and easy to realize miniaturization. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Non-contacting creep strain determination at 550 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Z.; Zarrabi, K.; Humphries, S.; Croker, A.; Small, R

    2003-06-01

    The digital speckle correlation technique (DSCT) is a non-contacting and whole field displacement/strain measurement system that has been successfully applied to a variety of applications. The technique is based on correlating the speckle surface of the object before and after deformation. It is best suited for flat surfaces. Creep deformation may, however, cause decorrelation of the speckle surface. The ability of DSCT to measure creep displacement/strain fields at 550 deg. C using 2.25%Cr 1%Mo steel specimens was evaluated. The specimens were cylindrical so that the effect of a non-flat surface was also included. Results show that DSCT can measure creep displacement and strain fields under laboratory conditions with less than 5% error. Further research and development work are required to assess the applicability of DSCT for creep displacement/strain measurements under field conditions.

  5. Non-contact measurement of rotation angle with solo camera

    Science.gov (United States)

    Gan, Xiaochuan; Sun, Anbin; Ye, Xin; Ma, Liqun

    2015-02-01

    For the purpose to measure a rotation angle around the axis of an object, a non-contact rotation angle measurement method based on solo camera was promoted. The intrinsic parameters of camera were calibrated using chessboard on principle of plane calibration theory. The translation matrix and rotation matrix between the object coordinate and the camera coordinate were calculated according to the relationship between the corners' position on object and their coordinates on image. Then the rotation angle between the measured object and the camera could be resolved from the rotation matrix. A precise angle dividing table (PADT) was chosen as the reference to verify the angle measurement error of this method. Test results indicated that the rotation angle measurement error of this method did not exceed +/- 0.01 degree.

  6. Predictive current control of permanent magnet synchronous motor based on linear active disturbance rejection control

    Science.gov (United States)

    Li, Kunpeng

    2017-01-01

    The compatibility problem between rapidity and overshooting in the traditional predictive current control structure is inevitable and difficult to solve by reason of using PI controller. A novel predictive current control (PCC) algorithm for permanent magnet synchronous motor (PMSM) based on linear active disturbance rejection control (LADRC) is presented in this paper. In order to displace PI controller, the LADRC strategy which consisted of linear state error feedback (LSEF) control algorithm and linear extended state observer (LESO), is designed based on the mathematic model of PMSM. The purpose of LSEF is to make sure fast response to load mutation and system uncertainties, and LESO is designed to estimate the uncertain disturbances. The principal structures of the proposed system are speed outer loop based on LADRC and current inner loop based on predictive current control. Especially, the instruction value of qaxis current in inner loop is derived from the control quantity which is designed in speed outer loop. The simulation is carried out in Matlab/Simulink software, and the results illustrate that the dynamic and static performances of proposed system are satisfied. Moreover the robust against model parameters mismatch is enhanced obviously.

  7. Electromagnetic Performance Calculation of HTS Linear Induction Motor for Rail Systems

    Science.gov (United States)

    Liu, Bin; Fang, Jin; Cao, Junci; Chen, Jie; Shu, Hang; Sheng, Long

    2017-07-01

    According to a high temperature superconducting (HTS) linear induction motor (LIM) designed for rail systems, the influence of electromagnetic parameters and mechanical structure parameters on the electromagnetic horizontal thrust, vertical force of HTS LIM and the maximum vertical magnetic field of HTS windings are analyzed. Through the research on the vertical field of HTS windings, the development regularity of the HTS LIM maximum input current with different stator frequency and different thickness value of the secondary conductive plate is obtained. The theoretical results are of great significance to analyze the stability of HTS LIM. Finally, based on theory analysis, HTS LIM test platform was built and the experiment was carried out with load. The experimental results show that the theoretical analysis is correct and reasonable.

  8. Improved linear ultrasonic motor performance with square-wave based driving-tip trajectory

    International Nuclear Information System (INIS)

    Le, Adam Y; Mills, James K; Benhabib, Beno

    2015-01-01

    This paper proposes the application of a non-sinusoidal periodic excitation voltage to induce a near-square-wave driving tip trajectory in linear ultrasonic motors (LUSMs). A square-wave-based trajectory can deliver superior frictional force to the moving stage in the forward stroke of the driving tip motion and reduced frictional force during the return stroke. This would reduce lost power in the periodic driving tip motion, thereby, increasing the output force and power of the LUSM. An implementation procedure is suggested to achieve the near-square-wave driving tip trajectory. The proposed approach is illustrated through realistic finite-element-based simulations using a bimodal LUSM configuration. (technical note)

  9. Recession in a linear stepper motor based on piezoelectric actuator and electrorheological clampers

    International Nuclear Information System (INIS)

    Li, Cuihong; Meng, Yonggang; Tian, Yu

    2012-01-01

    A linear inchworm-type stepper motor based on piezoelectric actuator and comb shape electrorheological (ER) clampers was developed and tested. A recession phenomenon in the movement of the motor was found and was significantly affected by the driving voltage of the piezoelectric actuator and ER fluids. A dynamic model to analyze the mechanism of the recession was established. The force ratio of the viscoelastic clamping force (applied high electric field) to the viscous damping force (zero field) of ER fluids is the critical factor which determines the recession. The ratio is also affected by the extension or contraction rate of the actuator during movement, which is affected by the charging and discharging processes. With a relatively large distance between the clamper electrodes and a small displacement activated by the extension of the piezoelectric actuator, the instantaneous shear rate might not be sufficiently high, preventing ER fluids from attaining a shear-thickened and high-strength state. The ratio of yield strength to the viscous strength of ER fluids during movement should be as large as possible to reduce the recession displacement. (paper)

  10. A novel L-shaped linear ultrasonic motor operating in a single resonance mode

    Science.gov (United States)

    Zhang, Bailiang; Yao, Zhiyuan; Liu, Zhen; Li, Xiaoniu

    2018-01-01

    In this study, a large thrust linear ultrasonic motor using an L-shaped stator is described. The stator is constructed by two mutually perpendicular rectangular plate vibrators, one of which is mounted in parallel with the slider to make the motor structure to be more compact. The symmetric and antisymmetric modes of the stator based on the first order bending vibration of two vibrators are adopted, in which each resonance mode is assigned to drive the slider in one direction. The placement of piezoelectric ceramics in a stator could be determined by finite element analysis, and the influence of slots in the head block on the vibration amplitudes of driving foot was studied as well. Three types of prototypes (non-slotted, dual-slot, and single-slot) were fabricated and experimentally investigated. Experimental results demonstrated that the prototype with one slot exhibited the best mechanical output performance. The maximum loads under the excitation of symmetric mode and antisymmetric mode were 65 and 90 N, respectively.

  11. Development of linear pulse motor type control element drive mechanism for smart

    International Nuclear Information System (INIS)

    Je-Yong, Yu; Jong-in, Kim; Ji-ho, Kim; Hyung, Huh; Moon-Hee, Chang

    2001-01-01

    The system-integrated modular advanced reactor (SMART) currently under development at the Korea Atomic Energy Research Institute is being designed with soluble boron free operation and the use of nuclear heating for reactor start-up. These design features require a Control Element Drive Mechanism(CEDM) for SMART to have fine-step movement capability as well as high reliability for fine reactivity control. In this paper, the design characteristics of a new concept CEDM driven by a Linear Pulse Motor (LPM) which meets the design requirements of the integral reactor SMART are introduced. The primary dimensions of the linear pulse motor are determined by electro-magnetic analysis and the results are also presented. In parallel with the electro-magnetic analysis, the conceptual design of the CEDM is visualized and checked for interferences among parts by assembling three dimensional (3D) models on computer. A prototype of the LPM with double air-gaps for the CEDM sub-assemblies to lift 100 kg is designed, analysed, manufactured and tested to confirm the validity of the CEDM design concept. A converter and test facility are manufactured to verify the dynamic performance of the LPM. The mover of the LPM is welded with ferromagnetic material and non-ferromagnetic material to get the magnetic flux path between the inner stator and outer stator. The thrust forces of LPM predicted by the analytic model have shown good agreement with experimental results from the prototype LPM. It is found that the LPM type CEDM has high force density and a simple drive mechanism to reduce volume and satisfy reactor operating circumstances with high pressure and temperature. (authors)

  12. Linear pulse motor type control element drive mechanism for the integral reactor

    International Nuclear Information System (INIS)

    Yu, J. Y.; Choi, S.; Kim, J. H.; Huh, H.; Park, K. B.

    2007-01-01

    The integral reactor SMART currently under development at Korea Atomic Energy Research Institute is designed with soluble boron free operation and use of nuclear heating for reactor startup. These design features require the Control Element Drive Mechanism (CEDM) for SMART to have fine-step movement capability as well as high reliability for the fine reactivity control. In this paper, design characteristics of a new concept CEDM driven by the Linear Pulse Motor (LPM) which meets the design requirements of the integral reactor SMART are introduced. The primary dimensions of the linear pulse motor are determined by the electro-magnetic analysis and the results are also presented. In parallel with the electro-magnetic analysis, the conceptual design of the CEDM is visualized and checked for interferences among parts by assembling three dimensional (3D) models on the computer. Prototype of LPM with double air-gaps for the CEDM sub-assemblies to lift 100 kg is designed, analysed, manufactured and tested to confirm the validity of the CEDM design concept. A converter and a test facility are manufactured to verify the dynamic performance of the LPM. The mover of the LPM is welded with ferromagnetic material and non-ferromagnetic material to get the magnetic flux path between inner stator and outer stator. The thrust forces of LPM predicted by analytic model have shown good agreement with experimental results from the prototype LPM. It is found that the LPM type CEDM has high force density and simple drive mechanism to reduce volume and satisfy the reactor operating circumstances with high pressure and temperature

  13. Novel Synchronous Linear and Rotatory Micro Motors Based on Polymer Magnets with Organic and Inorganic Insulation Layers

    Directory of Open Access Journals (Sweden)

    Andreas WALDSCHIK

    2008-12-01

    Full Text Available In this work, we report on the development of several synchronous motors with rotatory or linear movements. The synchronous micro motors are brushless DC motors or stepper motors with electrically controlled commutation consisting of a stator and a rotor. The rotor is mounted onto the stator and is adjusted by an integrated guidance. Inside the stator different coil systems are realized, like double layer sector coils or special nested coils. The coil systems can be controlled by three or six phases depending on the operational mode. Furthermore, inorganic insulation layers were used in order to reduce the thickness of the system. By this means four layers of electrical conductors can be realized especially for the 2D devices. The smallest diameter of the rotatory motor is 1 mm and could be successfully driven.

  14. Mathematical Model and Computational Analysis of Selected Transient States of Cylindrical Linear Induction Motor Fed via Frequency Converter

    Directory of Open Access Journals (Sweden)

    Andrzej Rusek

    2008-01-01

    Full Text Available The mathematical model of cylindrical linear induction motor (C-LIM fed via frequency converter is presented in the paper. The model was developed in order to analyze numerically the transient states. Problems concerning dynamics of ac-machines especially linear induction motor are presented in [1 – 7]. Development of C-LIM mathematical model is based on circuit method and analogy to rotary induction motor. The analogy between both: (a stator and rotor windings of rotary induction motor and (b winding of primary part of C-LIM (inductor and closed current circuits in external secondary part of C-LIM (race is taken into consideration. The equations of C-LIM mathematical model are presented as matrix together with equations expressing each vector separately. A computational analysis of selected transient states of C-LIM fed via frequency converter is presented in the paper. Two typical examples of C-LIM operation are considered for the analysis: (a starting the motor at various static loads and various synchronous velocities and (b reverse of the motor at the same operation conditions. Results of simulation are presented as transient responses including transient electromagnetic force, transient linear velocity and transient phase current.

  15. Study on Thrust Improvement and Ripple Suppression of HTS Linear Switched Reluctance Motor with Coreless HTS Excitation Windings

    Science.gov (United States)

    Oto, Satoshi; Hirayama, Tadashi; Kawabata, Shuma

    This paper describes a linear switched reluctance motor (LSRM) in which HTS tapes are used for coreless excitation windings in order to reduce the thrust ripple and normal force. This LSRM consists of a mover with saliency structure, coreless HTS coils and a stator back yoke. In this paper, we first describe the operating principle of the HTS-LSRM. Next, we calculate performances of the HTS-LSRM using 3-D FEM analysis. The effects of the motor structure on the thrust characteristic and normal force characteristics are clarified from the numerical results. Furthermore, we investigate the motor structure for thrust improvement, thrust ripple and normal force reduction.

  16. Fuzzy virtual reference model sensorless tracking control for linear induction motors.

    Science.gov (United States)

    Hung, Cheng-Yao; Liu, Peter; Lian, Kuang-Yow

    2013-06-01

    This paper introduces a fuzzy virtual reference model (FVRM) synthesis method for linear induction motor (LIM) speed sensorless tracking control. First, we represent the LIM as a Takagi-Sugeno fuzzy model. Second, we estimate the immeasurable mover speed and secondary flux by a fuzzy observer. Third, to convert the speed tracking control into a stabilization problem, we define the internal desired states for state tracking via an FVRM. Finally, by solving a set of linear matrix inequalities (LMIs), we obtain the observer gains and the control gains where exponential convergence is guaranteed. The contributions of the approach in this paper are threefold: 1) simplified approach--speed tracking problem converted into stabilization problem; 2) omit need of actual reference model--FVRM generates internal desired states; and 3) unification of controller and observer design--control objectives are formulated into an LMI problem where powerful numerical toolboxes solve controller and observer gains. Finally, experiments are carried out to verify the theoretical results and show satisfactory performance both in transient response and robustness.

  17. High magnetic field ohmically decoupled non-contact technology

    Science.gov (United States)

    Wilgen, John [Oak Ridge, TN; Kisner, Roger [Knoxville, TN; Ludtka, Gerard [Oak Ridge, TN; Ludtka, Gail [Oak Ridge, TN; Jaramillo, Roger [Knoxville, TN

    2009-05-19

    Methods and apparatus are described for high magnetic field ohmically decoupled non-contact treatment of conductive materials in a high magnetic field. A method includes applying a high magnetic field to at least a portion of a conductive material; and applying an inductive magnetic field to at least a fraction of the conductive material to induce a surface current within the fraction of the conductive material, the surface current generating a substantially bi-directional force that defines a vibration. The high magnetic field and the inductive magnetic field are substantially confocal, the fraction of the conductive material is located within the portion of the conductive material and ohmic heating from the surface current is ohmically decoupled from the vibration. An apparatus includes a high magnetic field coil defining an applied high magnetic field; an inductive magnetic field coil coupled to the high magnetic field coil, the inductive magnetic field coil defining an applied inductive magnetic field; and a processing zone located within both the applied high magnetic field and the applied inductive magnetic field. The high magnetic field and the inductive magnetic field are substantially confocal, and ohmic heating of a conductive material located in the processing zone is ohmically decoupled from a vibration of the conductive material.

  18. Anthropometry of external auditory canal by non-contactable measurement.

    Science.gov (United States)

    Yu, Jen-Fang; Lee, Kun-Che; Wang, Ren-Hung; Chen, Yen-Sheng; Fan, Chun-Chieh; Peng, Ying-Chin; Tu, Tsung-Hsien; Chen, Ching-I; Lin, Kuei-Yi

    2015-09-01

    Human ear canals cannot be measured directly with existing general measurement tools. Furthermore, general non-contact optical methods can only conduct simple peripheral measurements of the auricle and cannot obtain the internal ear canal shape-related measurement data. Therefore, this study uses the computed tomography (CT) technology to measure the geometric shape of the ear canal and the shape of the ear canal using a non-invasive method, and to complete the anthropometry of external auditory canal. The results of the study show that the average height and width of ear canal openings, and the average depth of the first bend for men are generally longer, wider and deeper than those for women. In addition, the difference between the height and width of the ear canal opening is about 40% (p < 0.05). Hence, the circular cross-section shape of the earplugs should be replaced with an elliptical cross-section shape during manufacturing for better fitting. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  19. Non-contact wearable single forearm cardiac biopotential acquisition device

    International Nuclear Information System (INIS)

    Gonçalves, Sérgio; Martins, Raul Carneiro

    2013-01-01

    In this work the authors propose a novel approach to obtain the electrocardiogram in the forearm using non-contact sensing. This new solution should be at same time portable, ergonomic and robust, enabling its use in different set of applications. A system of four electrodes was used in an adjustable sleeve to be wrapped in the forearm. No additional electrode references were used in other body parts. In order to increase the sensitivity of the system, an harmonium like approach was used in the design of the electrodes. The prototype was then compared with a similar system with a flat conformation. The developed prototype enabled the acquisition of an ECG signal in the forearm and the inclusion of the harmonium like electrode conformation resulted in a considerable increase of the sensitivity of the system. The acquired signal did not enable the identification of all characteristic cardiac waves. However, it was possible to identify clearly a signal pattern, characteristic of the QRS complex. The properties of the acquired signal restrict their use in rigorous electrocardiographic studies, allowing, however, its application in heart rate variability monitoring and biometric identification without the disadvantages usually associated with conventional electrodes. This makes it specially useful for man-machine interfaces and automated identification

  20. Comparison of non-contact infrared skin thermometers.

    Science.gov (United States)

    Fletcher, Thomas; Whittam, Aaron; Simpson, Rob; Machin, Graham

    2018-03-01

    Non-contact infra-red skin thermometers (NCITs) are becoming more prevalent for use in medical diagnostics. Not only are they used as an alternative means of estimating core body temperature but also to assess the diabetic foot for signs of inflammation prior to ulceration. Previous investigations have compared the performance of NCITs in a clinical setting against other gold standard methods. However, there have been no previous investigations comparing the performance of NCITs in assessing temperature measurement capability traceable to the International Temperature Scale of 1990 (ITS-90). A metrological assessment of nine common NCITs was carried out over the temperature range of 15-45 °C using the National Physical Laboratory's blackbody reference sources to identify their accuracy, repeatability, size-of-source and distance effects. The results are concerning in that five of the NCITs fell far outside the accuracy range stated by their manufacturers as well as the medical standard to which the NCITs are supposed to adhere. Furthermore, a 6 °C step change in measurement error over the temperature range of interest for the diabetic foot was found for one NCIT. These results have implications for all clinicians using NCITs for temperature measurement and demonstrate the need for traceable calibration to ITS-90.

  1. Application of the Hyper-Poisson Generalized Linear Model for Analyzing Motor Vehicle Crashes.

    Science.gov (United States)

    Khazraee, S Hadi; Sáez-Castillo, Antonio Jose; Geedipally, Srinivas Reddy; Lord, Dominique

    2015-05-01

    The hyper-Poisson distribution can handle both over- and underdispersion, and its generalized linear model formulation allows the dispersion of the distribution to be observation-specific and dependent on model covariates. This study's objective is to examine the potential applicability of a newly proposed generalized linear model framework for the hyper-Poisson distribution in analyzing motor vehicle crash count data. The hyper-Poisson generalized linear model was first fitted to intersection crash data from Toronto, characterized by overdispersion, and then to crash data from railway-highway crossings in Korea, characterized by underdispersion. The results of this study are promising. When fitted to the Toronto data set, the goodness-of-fit measures indicated that the hyper-Poisson model with a variable dispersion parameter provided a statistical fit as good as the traditional negative binomial model. The hyper-Poisson model was also successful in handling the underdispersed data from Korea; the model performed as well as the gamma probability model and the Conway-Maxwell-Poisson model previously developed for the same data set. The advantages of the hyper-Poisson model studied in this article are noteworthy. Unlike the negative binomial model, which has difficulties in handling underdispersed data, the hyper-Poisson model can handle both over- and underdispersed crash data. Although not a major issue for the Conway-Maxwell-Poisson model, the effect of each variable on the expected mean of crashes is easily interpretable in the case of this new model. © 2014 Society for Risk Analysis.

  2. Non-contact measurement of ocular microtremor using laser speckle

    Science.gov (United States)

    Kenny, E.; Coakley, D.; Boyle, G.

    2010-04-01

    The human eye moves continuously even while it appears to be at rest. The involuntary eye movements causing this motion are called fixational eye movements. Ocular Microtremor (OMT) is the smallest (150 - 2500nm amplitude) and fastest (~ 80Hz) of these eye movements. OMT has been proven to provide useful clinical information regarding depth of consciousness and neurological disorders. Most quantitative clinical investigations of OMT have been carried out using an eye-contacting piezoelectric probe. However, this measurement procedure suffers from a number of disadvantages which limit the potential of the technique in the clinical environment. The need for eye contact requires the eye to be anaesthetised and not all subjects can tolerate the procedure. A promising alternative to the piezoelectric technique is speckle metrology. A speckle correlation instrument for measuring OMT was first described by Al-Kalbani et al. The approach presented in this paper is a non contact measurement technique implementing laser speckle correlation and using a highly light sensitive video camera operating at 500Hz. The OMT measurement technique in this paper was investigated using a human subject and an eye movement simulator. Using this system, measurement of speckle on the eye takes only a few minutes, no eye drops are necessary and no discomfort is caused to the subject. The paper describes the preliminary results of capturing speckle from the simulator and from the human eye in-vivo at eye safe laser powers. The effects of tear flow, biospeckle and speckle shifting by larger eye movements on the displacement information carried by the speckle are also discussed.

  3. Signal transmission from motor axons to group Ia muscle spindle afferents: frequency responses and second-order non-linearities.

    Science.gov (United States)

    Windhorst, U; Kokkoroyiannis, T; Laouris, Y; Meyer-Lohmann, J

    1994-03-01

    Spinal recurrent inhibition via Renshaw cells and proprioceptive feedback via skeletal muscle and muscle spindle afferents have been hypothesized to constitute a compound feedback system [Windhorst (1989) Afferent Control of Posture and Locomotion; Windhorst (1993) Robots and Biological Systems--Towards a New Bionics]. To assess their detailed functions, it is necessary to know their dynamic characteristics. Previously we have extensively described the properties of signal transmission from motor axons to Renshaw cells using random motor axon stimulation and data analysis methods based thereupon. Using the same methods, we here compare these properties, in the cat, with those between motor axons and group Ia muscle spindle afferents in terms of frequency responses and nonlinear features. The frequency responses depend on the mean rate (carrier rate) of activation of motor axons and on the strength of coupling between motor units and spindles. In general, they are those of a second-order low-pass system with a cut-off at fairly low frequencies. This contrasts with the dynamics of motor axon-Renshaw cell couplings which are those of a much broader band-pass with its peak in the range of c. 2-15 Hz [Christakos (1987) Neuroscience 23, 613-623]. The second-order non-linearities in motor unit-muscle spindle signal lines are much more diverse than those in motor axon-Renshaw cell couplings. Although the average strength of response declines with mean stimulus rate in both subsystems, there is no systematic relationship between the amount of non-linearity and the average response in the former, whilst there is in the latter. The qualitative appearance of motor unit-muscle spindle non-linearities was complicated as was the average response to motor unit twitches. Thus, whilst Renshaw cells appear to dynamically reflect motor output rather faithfully, muscle spindles seem to signal local muscle fibre length changes and their dynamics. This would be consistent with the

  4. Analysis and testing of a double armature brushless dc linear motor with NdFeB permanent magnets

    International Nuclear Information System (INIS)

    Filho, A.F.F.

    1998-01-01

    The use of high-energy product NdFeB permanent magnets benefits the design and features of a double armature brushless dc linear motor. As the linear motor is also slotless, its 5 mm airgap requires a source of high flux to overcome the reluctance and produce an adequate amount of force. The linear motor employs a topology that makes use of five permanent magnets to provide excitation flux. The permanent magnets are arranged in such a way that maximises the force the linear motor can deliver. The actuator produces a force up to 86.2 N at an armature current of 4.5 A. However, the topology makes the actuator prone to saturation. It affects the operation point of the permanent magnets, reduces the airgap flux density and the force, and increases flux leakage. To avoid saturation, a flux compensation scheme was conceived. The results are presented and assessed by means of finite element simulation and by experimental results that presented a good agreement. (orig.)

  5. Barriers to Predicting the Mechanisms and Risk Factors of Non-Contact Anterior Cruciate Ligament Injury

    OpenAIRE

    Ali, Nicholas; Rouhi, Gholamreza

    2010-01-01

    High incidences of non-contact anterior cruciate ligament (ACL) injury, frequent requirements for ACL reconstruction, and limited understanding of ACL mechanics have engendered considerable interest in quantifying the ACL loading mechanisms. Although some progress has been made to better understand non-contact ACL injuries, information on how and why non-contact ACL injuries occur is still largely unavailable. In other words, research is yet to yield consensus on injury mechanisms and risk fa...

  6. Integrating optopiezoelectric actuators and a two-mode excited linear ultrasonic motor for microfluidics

    Science.gov (United States)

    Chen, Tsun-Hsu; Wang, Hsin-Hu; Hsu, Yu-Hsiang; Lee, Chih-Kung

    2016-03-01

    In comparison to more developed optical method for microparticle manipulation like optical tweezers, an optopiezoelectric actuating system could provide force output that is several orders higher. Taking advantages of photoconductive materials, the concept of integrating a virtual electrode in a distributed opto-piezoelectric actuators was developed for real-time in-situ spatial tailoring for vast varieties of applications in biochips, smart structures, etc. In this study, photoconductive material titanium oxide phthalocyanine (TiOPc) was used as the active ingredient to enable the virtual electrode in an opto-piezoelectric material based distributed actuator. By illuminating light of proper wavelength and enough intensity onto TiOPc photoconductive material, the effective impedance of the illuminated portion of TiOPc could drop significantly. The contributions of using additives in the TiOPc photoconductive electrode to adjust the electrical properties was investigated for optimization. Further, the two-mode excited linear ultrasonic motor was also studied and the feasibility to integrate the TiOPc photoconductive electrode was discussed. The flexibility provided by this newly developed system could potential deliver versatile performance in biochip applications.

  7. Non-contact luminescence lifetime cryothermometry for macromolecular crystallography.

    Science.gov (United States)

    Mykhaylyk, V B; Wagner, A; Kraus, H

    2017-05-01

    Temperature is a very important parameter when aiming to minimize radiation damage to biological samples during experiments that utilize intense ionizing radiation. A novel technique for remote, non-contact, in situ monitoring of the protein crystal temperature has been developed for the new I23 beamline at the Diamond Light Source, a facility dedicated to macromolecular crystallography (MX) with long-wavelength X-rays. The temperature is derived from the temperature-dependent decay time constant of luminescence from a minuscule scintillation sensor (<0.05 mm 3 ) located in very close proximity to the sample under test. In this work the underlying principle of cryogenic luminescence lifetime thermometry is presented, the features of the detection method and the choice of temperature sensor are discussed, and it is demonstrated how the temperature monitoring system was integrated within the viewing system of the endstation used for the visualization of protein crystals. The thermometry system was characterized using a Bi 4 Ge 3 O 12 crystal scintillator that exhibits good responsivity of the decay time constant as a function of temperature over a wide range (8-270 K). The scintillation sensor was calibrated and the uncertainty of the temperature measurements over the primary operation temperature range of the beamline (30-150 K) was assessed to be ±1.6 K. It has been shown that the temperature of the sample holder, measured using the luminescence sensor, agrees well with the expected value. The technique was applied to characterize the thermal performance of different sample mounts that have been used in MX experiments at the I23 beamline. The thickness of the mount is shown to have the greatest impact upon the temperature distribution across the sample mount. Altogether, these tests and findings demonstrate the usefulness of the thermometry system in highlighting the challenges that remain to be addressed for the in-vacuum MX experiment to become a

  8. Analysis and Design of a Maglev Permanent Magnet Synchronous Linear Motor to Reduce Additional Torque in dq Current Control

    Directory of Open Access Journals (Sweden)

    Feng Xing

    2018-03-01

    Full Text Available The maglev linear motor has three degrees of motion freedom, which are respectively realized by the thrust force in the x-axis, the levitation force in the z-axis and the torque around the y-axis. Both the thrust force and levitation force can be seen as the sum of the forces on the three windings. The resultant thrust force and resultant levitation force are independently controlled by d-axis current and q-axis current respectively. Thus, the commonly used dq transformation control strategy is suitable for realizing the control of the resultant force, either thrust force and levitation force. However, the forces on the three windings also generate additional torque because they do not pass the mover mass center. To realize the maglev system high-precision control, a maglev linear motor with a new structure is proposed in this paper to decrease this torque. First, the electromagnetic model of the motor can be deduced through the Lorenz force formula. Second, the analytic method and finite element method are used to explore the reason of this additional torque and what factors affect its change trend. Furthermore, a maglev linear motor with a new structure is proposed, with two sets of 90 degrees shifted winding designed on the mover. Under such a structure, the mover position dependent periodic part of the additional torque can be offset. Finally, the theoretical analysis is validated by the simulation result that the additionally generated rotating torque can be offset with little fluctuation in the proposed new-structure maglev linear motor. Moreover, the control system is built in MATLAB/Simulink, which shows that it has small thrust ripple and high-precision performance.

  9. 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.

  10. EEG sensorimotor rhythms' variation and functional connectivity measures during motor imagery: linear relations and classification approaches.

    Science.gov (United States)

    Stefano Filho, Carlos A; Attux, Romis; Castellano, Gabriela

    2017-01-01

    Hands motor imagery (MI) has been reported to alter synchronization patterns amongst neurons, yielding variations in the mu and beta bands' power spectral density (PSD) of the electroencephalography (EEG) signal. These alterations have been used in the field of brain-computer interfaces (BCI), in an attempt to assign distinct MI tasks to commands of such a system. Recent studies have highlighted that information may be missing if knowledge about brain functional connectivity is not considered. In this work, we modeled the brain as a graph in which each EEG electrode represents a node. Our goal was to understand if there exists any linear correlation between variations in the synchronization patterns-that is, variations in the PSD of mu and beta bands-induced by MI and alterations in the corresponding functional networks. Moreover, we (1) explored the feasibility of using functional connectivity parameters as features for a classifier in the context of an MI-BCI; (2) investigated three different types of feature selection (FS) techniques; and (3) compared our approach to a more traditional method using the signal PSD as classifier inputs. Ten healthy subjects participated in this study. We observed significant correlations ( p  classification, with mean accuracies of (90 ± 8)% and (87 ± 7)% for the mu and beta band, respectively, versus (83 ± 8)% and (83 ± 7)% for the same bands for the graph method. Moreover, the number of features for the graph method was considerably larger. However, results for both methods were relatively close, and even overlapped when the uncertainties of the accuracy rates were considered. Further investigation regarding a careful exploration of other graph metrics may provide better alternatives.

  11. Magnetic induction distribution in a linear synchronus motor with magnetic suspension

    OpenAIRE

    Голенков, Геннадій Михайлович; Пархоменко, Дмитро Ігорович

    2013-01-01

    Представлені результати комп'ютерного моделювання та експериментального дослідження розподілу магнітної індукції коаксіально-лінійного синхронного двигуна з магнітним підвісом (КЛСД-МП). Дослідження розподілу магнітної індукції проводилося в магнітному зазорі КЛСД-МП, а також на поверхні бігуна. Results of computer simulation and experimental investigations of magnetic induction distribution in a coaxial linear synchronous motor with magnetic suspension are presented. The magnetic inductio...

  12. Energy transfer, volumetric expansion, and removal of oral biofilms by non-contact brushing

    NARCIS (Netherlands)

    Busscher, H. J.; Jager, D.; Finger, G.; Schaefer, N.; van der Mei, H. C.

    Non-contact removal of oral biofilms offers advantages beyond the reach of bristles, but it is unknown how energy transfer for removal from brush-to-biofilm occurs. In the present study we evaluated non-contact, oral biofilm removal by oscillating-rotating and sonic toothbrushes, and their acoustic

  13. Comparison of experimental and theoretical reaction rail currents, rail voltages, and airgap fields for the linear induction motor research vehicle

    Science.gov (United States)

    Elliott, D. G.

    1977-01-01

    Measurements of reaction rail currents, reaction rail voltages, and airgap magnetic fields in tests of the Linear Induction Motor Research Vehicle (LIMRV) were compared with theoretical calculations from the mesh/matrix theory. It was found that the rail currents and magnetic fields predicted by the theory are within 20 percent of the measured currents and fields at most motor locations in most of the runs, but differ by as much as a factor of two in some cases. The most consistent difference is a higher experimental than theoretical magnetic field near the entrance of the motor and a lower experimental than theoretical magnetic field near the exit. The observed differences between the theoretical and experimental magnetic fields and currents do not account for the differences of as much as 26 percent between the theoretical and experimental thrusts.

  14. An analytical method for the calculation of static characteristics of linear step motors for control rod drives in nuclear reactors

    International Nuclear Information System (INIS)

    Khan, S.H.; Ivanov, A.A.

    1995-01-01

    An analytical method for calculating static characteristics of linear dc step motors (LSM) is described. These multiphase passive-armature motors are now being developed for control rod drives (CRD) in large nuclear reactors. The static characteristics of such LSM is defined by the variation of electromagnetic force with armature displacement and it determines motor performance in its standing and dynamic modes of operation. The proposed analytical technique for calculating this characteristic is based on the permeance analysis method applied to phase magnetic circuits of LSM. Reluctances of various parts of phase magnetic circuit is calculated analytically by assuming probable flux paths and by taking into account complex nature of magnetic field distribution in it. For given armature positions stator and armature iron saturations are taken into account by an efficient iterative algorithm which gives fast convergence. The method is validated by comparing theoretical results with experimental ones which shows satisfactory agreement for small stator currents and weak iron saturation

  15. Development of Propulsion Inverter Control System for High-Speed Maglev based on Long Stator Linear Synchronous Motor

    Directory of Open Access Journals (Sweden)

    Jeong-Min Jo

    2017-02-01

    Full Text Available In the case of a long-stator linear drive, unlike rotative drives for which speed or position sensors are a single unit attached to the shaft, these sensors extend along the guideway. The position signals transmitted from a maglev vehicle cannot meet the need of the real-time propulsion control in the on-ground inverter power substations. In this paper the design of the propulsion inverter control system with a position estimator for driving a long-stator synchronous motor in a high-speed maglev train is proposed. The experiments have been carried out at the 150 m long guideway at the O-song test track. To investigate the performance of the position estimator, the propulsion control system with, and without, the position estimator are compared. The result confirms that the proposed strategy can meet the dynamic property needs of the propulsion inverter control system for driving long-stator linear synchronous motors.

  16. Non-Contact Linear Actuator Position Sensor Having a PID-Compensating Controller

    Science.gov (United States)

    Alhorn, Dean C. (Inventor); Howard, David E. (Inventor)

    2001-01-01

    A position sensor or controller generates a response signal in existing armature windings of an actuator and detects the response signal to determine the position of the armature. To generate the response signal, the actuator includes a sensor excitation winding near the armature. Two sensor excitation windings can be provided, above and below the armature, to cancel out z components and thus allow for a variable gap. The sensor excitation winding or windings are supplied with an excitation signal to induce the response signal in the armature windings. The response signal is derived by differentially amplifying and frequency filtering a raw output of the armature windings. The response signal is demodulated to determine position. If a position controller rather than a mere sensor is desired, the position signal can be buffered, PID compensated, amplified, and fed back to the armature windings.

  17. Evaluation of anti-tuberculosis antibodies in healthy contact and non-contacts persons

    International Nuclear Information System (INIS)

    Aziz, N; Bukhari, M.H; Muneer, M; Tayyab, M; Chaudhry, N.A.

    2006-01-01

    This study was conducted to see the presence of the antimycobacterial antibodies in healthy household contacts of tuberculosis patients and healthy normal subjects who have never been in contact with tuberculosis patients. A total of 200 subjects, 120 with history of household contact and 80 without such history were included in the study. Routine Haematological investigations were performed and all the sera of 200 subjects were tested who 19M, 19G and IgA anti tuberculosis antibodies using ELISA technique. There was no difference in the average age of the household contacts and non-contacts. The complaints of pyrexia, night sweats and loss of weight was more in house hold contacts as compared to non-contacts. The awareness about BCG vaccination was equal among the household contacts and non-contacts. The combined serological positivity of the household contacts was 65.8% and the combined serological positivity for non-contacts was 34.1%. There was no statistically significant difference in the presence of 19M among household contacts as compared to non-contacts. However both IgG and 19A were present in significantly higher number of household contacts as compared to non contacts. This study concludes that the persons living in the house with a patient suffering from active pulmonary tuberculosis (household contact) have more chances of being infected with Mycobacterium tuberculosis as compared to the healthy non-contacts. (author)

  18. A novel large thrust-weight ratio V-shaped linear ultrasonic motor with a flexible joint

    Science.gov (United States)

    Li, Xiaoniu; Yao, Zhiyuan; Yang, Mojian

    2017-06-01

    A novel large thrust-weight ratio V-shaped linear ultrasonic motor with a flexible joint is proposed in this paper. The motor is comprised of a V-shaped transducer, a slider, a clamp, and a base. The V-shaped transducer consists of two piezoelectric beams connected through a flexible joint to form an appropriate coupling angle. The V-shaped motor is operated in the coupled longitudinal-bending mode. Longitudinal and bending movements are transferred by the flexible joint between the two beams. Compared with the coupled longitudinal-bending mode of the single piezoelectric beam or the symmetrical and asymmetrical modes of the previous V-shaped transducer, the coupled longitudinal-bending mode of the V-shaped transducer with a flexible joint provides higher vibration efficiency and more convenient mode conformance adjustment. A finite element model of the V-shaped transducer is created to numerically study the influence of geometrical parameters and to determine the final geometrical parameters. In this paper, three prototypes were then fabricated and experimentally investigated. The modal test results match well with the finite element analysis. The motor mechanical output characteristics of three different coupling angles θ indicate that V-90 (θ = 90°) is the optimal angle. The mechanical output experiments conducted using the V-90 prototype (Size: 59.4 mm × 30.7 mm × 4 mm) demonstrate that the maximum unloaded speed is 1.2 m/s under a voltage of 350 Vpp, and the maximum output force is 15 N under a voltage of 300 Vpp. The proposed novel V-shaped linear ultrasonic motor has a compact size and a simple structure with a large thrust-weight ratio (0.75 N/g) and high speed.

  19. METHOD OF NON-CONTACT PHOTOLUMINESCENT DIAGNOSTICS OF THE EYE FIBROUS TUNIC CONDITION

    Directory of Open Access Journals (Sweden)

    S. Yu. Petrov

    2018-01-01

    Full Text Available Non-contact optical diagnostics of structural disorders of the eye has a number of advantages: high speed, accuracy and a large range of parameters available for analysis. The paper presents the results of studies of the photoluminescence of the fibrous tunic of the eye, excited by polarized light, depending on the intraocular pressure. In the experiments, isolated de-epithelized eyes of the rabbit were used, inside of which pressure up to 50 mm Hg was artificially created. Under these conditions, the cornea and sclera were illuminated with linearly polarized light at wavelengths of 250, 350 and 450 nm, exciting photoluminescence in the wavelength range up to 700 nm. Cross and co-polarized photoluminescence spectra excited by linearly polarized light were obtained. It has been established that, when excited by polarized light, the photoluminescence of the cornea is partially polarized. Depending on the wavelength of the photoluminescence, the degree of polarization varies from 0.2 to 0.35. It is shown that the degree of polarization of the photoluminescence of the cornea of the eye upon excitation by linearly polarized light can be used as a measurable parameter for assessing the physiological state of the eye. It is shown that the photoluminescence spectrum consists of two bands with maxima near 460-470 and 430-440 nm. These bands are assigned, respectively, to pyridinnucleotides and glycosylated collagen. A significant contribution can be made by the epithelium of the eye, which contains riboflavin with characteristic absorption bands near 450 and 365 nm. When excited at 450 nm, the photoluminescence maximum is located near 540 nm, which corresponds to the spectrum of fluorophores in the endothelium and epithelium. The spectrum of photoluminescence upon excitation at a wavelength of 250 nm can be attributed to tryptophan located in the intraocular lens.

  20. Behaviour of human motor units in different muscles during linearly varying contractions

    Science.gov (United States)

    de Luca, C. J.; LeFever, R. S.; McCue, M. P.; Xenakis, A. P.

    1982-01-01

    1. The electrical activity of up to eight concurrently active motor units has been recorded from the human deltoid and first dorsal interosseous (f.d.i.) muscles. The detected myoelectric signals have been decomposed into their constituent motor-unit action potential trains using a recently developed technique. 2. Concurrently active motor unit behaviour has been examined during triangular force-varying isometric contractions reaching 40 and 80% of maximal voluntary contraction (m.v.c.). Experiments were performed on four normal subjects and three groups of highly trained performers (long-distance swimmers, powerlifters and pianists). 3. Results revealed a highly ordered recruitment and decruitment scheme, based on motoneurone excitability, in both muscles and in all subject groups. 4. Differences were observed between the initial (recruitment) and final (decruitment) firing rates in each muscle. These parameters were invariant with respect to the force rates studied, although some differences were observed among subject groups. 5. In general, firing rates of f.d.i. motor units increased steadily with increasing force (up to 80% m.v.c.). The firing rates of deltoid motor units rose sharply just after recruitment and then increased only slightly thereafter. 6. Recruitment was found to be the major mechanism for generating extra force between 40 and 80% m.v.c. in the deltoid, while rate coding played the major role in the f.d.i. 7. The potential of rate coding for increasing force levels up to m.v.c. is discussed. PMID:7143246

  1. Sensor-Motor Maps for Describing Linear Reflex Composition in Hopping

    Directory of Open Access Journals (Sweden)

    Christian Schumacher

    2017-11-01

    Full Text Available In human and animal motor control several sensory organs contribute to a network of sensory pathways modulating the motion depending on the task and the phase of execution to generate daily motor tasks such as locomotion. To better understand the individual and joint contribution of reflex pathways in locomotor tasks, we developed a neuromuscular model that describes hopping movements. In this model, we consider the influence of proprioceptive length (LFB, velocity (VFB and force feedback (FFB pathways of a leg extensor muscle on hopping stability, performance and efficiency (metabolic effort. Therefore, we explore the space describing the blending of the monosynaptic reflex pathway gains. We call this reflex parameter space a sensor-motor map. The sensor-motor maps are used to visualize the functional contribution of sensory pathways in multisensory integration. We further evaluate the robustness of these sensor-motor maps to changes in tendon elasticity, body mass, segment length and ground compliance. The model predicted that different reflex pathway compositions selectively optimize specific hopping characteristics (e.g., performance and efficiency. Both FFB and LFB were pathways that enable hopping. FFB resulted in the largest hopping heights, LFB enhanced hopping efficiency and VFB had the ability to disable hopping. For the tested case, the topology of the sensor-motor maps as well as the location of functionally optimal compositions were invariant to changes in system designs (tendon elasticity, body mass, segment length or environmental parameters (ground compliance. Our results indicate that different feedback pathway compositions may serve different functional roles. The topology of the sensor-motor map was predicted to be robust against changes in the mechanical system design indicating that the reflex system can use different morphological designs, which does not apply for most robotic systems (for which the control often follows a

  2. ChemCam-like Spectrometer for Non-Contact Measurements of Key Isotopes, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This project addresses the need for a non-contact instrument capable of measuring the isotopic ratios O-18/O-16 and D/H from water ice and other solid materials...

  3. ChemCam-like Spectrometer for Non-Contact Measurements of Key Isotopes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project addresses the need for a non-contact instrument capable of measuring the isotopic ratios O-18/O-16 and D/H from water ice and other solid materials...

  4. Practical Non-contact ECG Electrodes for Prep-free Monitoring, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Cognionics has developed a high-quality, low-noise, dry/non-contact ECG electrode that can obtain signals even through layers of clothing without any skin...

  5. Freeform optics: a non-contact "test plate" for manufacturing, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this NASA SBIR Phase I study is to determine the feasibility of measuring precision (fractional wave) freeform optics using non-contact areal (imaging)...

  6. INNOVATIVE NON-CONTACT METROLOGY SOLUTIONS FOR LARGE OPTICAL TELESCOPES, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has unique non-contact precision metrology requirements for dimensionally inspecting the global position and orientation of large and highly-polished...

  7. Calculation of static characteristics of linear step motors for control rod drives of nuclear reactors - an approximate approach

    International Nuclear Information System (INIS)

    Khan, S.H.; Ivanov, A.A.

    1993-01-01

    This paper describes an approximate method for calculating the static characteristics of linear step motors (LSM), being developed for control rod drives (CRD) in large nuclear reactors. The static characteristic of such an LSM which is given by the variation of electromagnetic force with armature displacement determines the motor performance in its standing and dynamic modes. The approximate method of calculation of these characteristics is based on the permeance analysis method applied to the phase magnetic circuit of LSM. This is a simple, fast and efficient analytical approach which gives satisfactory results for small stator currents and weak iron saturation, typical to the standing mode of operation of LSM. The method is validated by comparing theoretical results with experimental ones. (Author)

  8. MODELING OF OPERATION OF COAXIAL-LINEAR MOTORS WITH AXIAL AND RADIAL DIRECTIONS OF MAGNETIZATION OF PERMANENT MAGNETS IN DYNAMIC MODE

    Directory of Open Access Journals (Sweden)

    G.M. Golenkov

    2014-12-01

    Full Text Available Theoretical and experimental investigations of the amplitude, phase and inertia-power frequency characteristics of two types of coaxial-linear electric motors of back-and-forth motion with permanent magnets, which magnetization vector is directed axially and radially relative to the axis of the runner are carried out. The comparative analysis of characteristics of these motors is presented.

  9. Optimal design of a double-sided linear motor with a multi-segmented trapezoidal magnet array for a high precision positioning system

    International Nuclear Information System (INIS)

    Lee, Moon G.; Gweon, Dae-Gab

    2004-01-01

    A comparative analysis is performed for linear motors adopting conventional and multi-segmented trapezoidal (MST) magnet arrays, respectively, for a high-precision positioning system. The proposed MST magnet array is a modified version of a Halbach magnet array. The MST array has trapezoidal magnets with variable shape and dimensions while the Halbach magnet array generally has a rectangular magnet with identical dimensions. We propose a new model that can describe the magnetic field resulting from the complex-shaped magnets. The model can be applied to both MST and conventional magnet arrays. Using the model, a design optimization of the two types of linear motors is performed and compared. The magnet array with trapezoidal magnets can produce more force than one with rectangular magnets when they are arrayed in a linear motor where there is a yoke with high permeability. After the optimization and comparison, we conclude that the linear motor with the MST magnet array can generate more actuating force per volume than the motor with the conventional array. In order to satisfy the requirements of next generation systems such as high resolution, high speed, and long stroke, the use of a linear motor with a MST array as an actuator in a high precision positioning system is recommended from the results obtained here

  10. Non Linear, Time Variant Speed Control of a Single Phase Hybrid Switched Reluctance Motor

    DEFF Research Database (Denmark)

    Jakobsen, Uffe; Ahn, Jin Woo

    2009-01-01

    A high torque ripple in a given motor always presents a challenge for the speed control, since this ripple may lead to excessive actuation and ultimately may even lead to instability. The conventional solution is to low pass filter the measured speed, but this lowers dynamic control performance. ....... This paper presents a new method to accurately calculate the average speed and a time variant approximation of the integrator to achieve good dynamics. Both simulation and measurement shows a good steady state performance, with a steady state error less than 0.4%....

  11. Non-contact magnetic coupled power and data transferring system for an electric vehicle

    Science.gov (United States)

    Matsuda, Y.; Sakamoto, H.

    2007-03-01

    We have developed a system which transmits electric power and communication data simultaneously in a non-contact method using a magnetic coupling coil. Already, we are developing the fundamental technology of a non-contact charging system, and this is applied in electric shavers, electric toothbrushes, etc. Moreover, basic experiments are being conducted for applying this non-contact charging system to electric equipments such as an electric vehicle (EV), which is a zero emission vehicle and environmentally excellent and will be the transportation means of the next generation. The technology can also be applied in other electronic equipment, etc. However, since the power supply route for these individual devices is independent, the supply system is complicated. EV also has to perform the transmission of electric power and the transmission of information (data), such as the amount of the charge, in a separate system, and thus is quite complicated. In this study, by performing simultaneously the transmission of electric power and information (data) using magnetic coupling technology in which it does not contact, the basic experiment aimed at attaining and making unification of a system simple was conducted, and the following good results were obtained: (1) Electric power required for load can be transmitted easily by non-contact. (2) A signal can easily be transmitted bidirectionally by non-contact. (3) This system is reliable, and is widely applicable.

  12. Complex motor task associated with non-linear BOLD responses in cerebro-cortical areas and cerebellum.

    Science.gov (United States)

    Alahmadi, Adnan A S; Samson, Rebecca S; Gasston, David; Pardini, Matteo; Friston, Karl J; D'Angelo, Egidio; Toosy, Ahmed T; Wheeler-Kingshott, Claudia A M

    2016-06-01

    Previous studies have used fMRI to address the relationship between grip force (GF) applied to an object and BOLD response. However, whilst the majority of these studies showed a linear relationship between GF and neural activity in the contralateral M1 and ipsilateral cerebellum, animal studies have suggested the presence of non-linear components in the GF-neural activity relationship. Here, we present a methodology for assessing non-linearities in the BOLD response to different GF levels, within primary motor as well as sensory and cognitive areas and the cerebellum. To be sensitive to complex forms, we designed a feasible grip task with five GF targets using an event-related visually guided paradigm and studied a cohort of 13 healthy volunteers. Polynomial functions of increasing order were fitted to the data. (1) activated motor areas irrespective of GF; (2) positive higher-order responses in and outside M1, involving premotor, sensory and visual areas and cerebellum; (3) negative correlations with GF, predominantly involving the visual domain. Overall, our results suggest that there are physiologically consistent behaviour patterns in cerebral and cerebellar cortices; for example, we observed the presence of a second-order effect in sensorimotor areas, consistent with an optimum metabolic response at intermediate GF levels, while higher-order behaviour was found in associative and cognitive areas. At higher GF levels, sensory-related cortical areas showed reduced activation, interpretable as a redistribution of the neural activity for more demanding tasks. These results have the potential of opening new avenues for investigating pathological mechanisms of neurological diseases.

  13. Non-contact optoacoustic imaging with focused air-coupled transducers

    Energy Technology Data Exchange (ETDEWEB)

    Deán-Ben, X. Luís [Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg (Germany); Pang, Genny A.; Razansky, Daniel, E-mail: dr@tum.de [Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg (Germany); School of Medicine, Technische Universität München (TUM), Munich (Germany); Montero de Espinosa, Francisco [CSIC, Institute of Physics and Communication Technologies, Madrid (Spain)

    2015-08-03

    Non-contact optoacoustic imaging employing raster-scanning of a spherically focused air-coupled ultrasound transducer is showcased herein. Optoacoustic excitation with laser fluence within the maximal permissible human exposure limits in the visible and near-infrared spectra is applied to objects with characteristic dimensions smaller than 1 mm and absorption properties representative of the whole blood at near-infrared wavelengths, and these signals are shown to be detectable without contact to the sample using an air-coupled transducer with reasonable signal averaging. Optoacoustic images of vessel-mimicking tubes embedded in an agar phantom captured with this non-contact sensing technique are also showcased. These initial results indicate that an air-coupled ultrasound detection approach can be suitable for non-contact biomedical imaging with optoacoustics.

  14. Amplitude modulation drive to rectangular-plate linear ultrasonic motors with vibrators dimensions 8 mm x 2.16 mm X 1 mm.

    Science.gov (United States)

    Ming, Yang; Hanson, Ben; Levesley, Martin C; Walker, Peter G; Watterson, Kevin G

    2006-12-01

    In this paper, to exploit the contribution from not only the stators but also from other parts of miniature ultrasonic motors, an amplitude modulation drive is proposed to drive a miniature linear ultrasonic motor consisting of two rectangular piezoelectric ceramic plates. Using finite-element software, the first longitudinal and second lateral-bending frequencies of the vibrator are shown to be very close when its dimensions are 8 mm x 2.16 mm x 1 mm. So one single frequency power should be able to drive the motor. However, in practice the motor is found to be hard to move with a single frequency power because of its small vibration amplitudes and big frequency difference between its longitudinal and bending resonance, which is induced by the boundary condition variation. To drive the motor effectively, an amplitude modulation drive is used by superimposing two signals with nearly the same frequencies, around the resonant frequency of the vibrators of the linear motor. When the amplitude modulation frequency is close to the resonant frequency of the vibrator's surroundings, experimental results show that the linear motor can move back and forward with a maximum thrust force (over 0.016 N) and a maximum velocity (over 50 mm/s).

  15. Barriers to predicting the mechanisms and risk factors of non-contact anterior cruciate ligament injury.

    Science.gov (United States)

    Ali, Nicholas; Rouhi, Gholamreza

    2010-01-01

    High incidences of non-contact anterior cruciate ligament (ACL) injury, frequent requirements for ACL reconstruction, and limited understanding of ACL mechanics have engendered considerable interest in quantifying the ACL loading mechanisms. Although some progress has been made to better understand non-contact ACL injuries, information on how and why non-contact ACL injuries occur is still largely unavailable. In other words, research is yet to yield consensus on injury mechanisms and risk factors. Biomechanics, video analysis, and related study approaches have elucidated to some extent how ACL injuries occur. However, these approaches are limited because they provide estimates, rather than precise measurements of knee - and more specifically ACL - kinematics at the time of injury. These study approaches are also limited in their inability to simultaneously capture many of the contributing factors to injury.This paper aims at elucidating and summarizing the key challenges that confound our understanding in predicting the mechanisms and subsequently identifying risk factors of non-contact ACL injury. This work also appraise the methodological rigor of existing study approaches, review testing protocols employed in published studies, as well as presents a possible coupled approach to better understand injury mechanisms and risk factors of non-contact ACL injury. Three comprehensive electronic databases and hand search of journal papers, covering numerous full text published English articles were utilized to find studies on the association between ACL and injury mechanisms, ACL and risk factors, as well as, ACL and investigative approaches. This review unveils that new research modalities and/or coupled research methods are required to better understand how and why the ACL gets injured. Only by achieving a better understanding of ACL loading mechanisms and the associated contributing factors, one will be able to develop robust prevention strategies and exercise

  16. A fast non-contact imaging photoplethysmography method using a tissue-like model

    Science.gov (United States)

    McDuff, Daniel J.; Blackford, Ethan B.; Estepp, Justin R.; Nishidate, Izumi

    2018-02-01

    Imaging photoplethysmography (iPPG) allows non-contact, concomitant measurement and visualization of peripheral blood flow using just an RGB camera. Most iPPG methods require a window of temporal data and complex computation, this makes real-time measurement and spatial visualization impossible. We present a fast,"window-less", non-contact imaging photoplethysmography method, based on a tissue-like model of the skin, that allows accurate measurement of heart rate and heart rate variability parameters. The error in heart rate estimates is equivalent to state-of-the-art techniques and computation is much faster.

  17. Non-contact optical measurement of lens capsule thickness during simulated accommodation

    Science.gov (United States)

    Ziebarth, Noel; Manns, Fabrice; Acosta, Ana-Carolina; Parel, Jean-Marie

    2005-04-01

    Purpose: To non-invasively measure the thickness of the anterior and posterior lens capsule, and to determine if it significantly changes during accommodation. Methods: Anterior and posterior capsule thickness was measured on post-mortem lenses using a non-contact optical system using a focus-detection technique. The optical system uses a 670nm laser beam delivered to a single-mode fiber coupler. The output of the fiber coupler is focused on the tissue surface using an aspheric lens (NA=0.68) mounted on a translation stage with a motorized actuator. Light reflected from the sample surface is collected by the fiber coupler and sent to a photoreceiver connected to a computer-controlled data acquisition system. Optical intensity peaks are detected when the aspheric lens is focused on the capsule boundaries. The capsule thickness is equal to the distance traveled between two peaks multiplied by the capsule refractive index. Anterior and posterior lens capsule thickness measurements were performed on 18 cynomolgus (age average: 6+/-1 years, range: 4-7 years) eyes, 1 rhesus (age: 2 years) eye, and 12 human (age average: 65+/-16, range: 47-92) eyes during simulated accommodation. The mounted sample was placed under the focusing objective of the optical system so that the light was incident on the center pole. Measurements were taken of the anterior lens capsule in the unstretched and the stretched 5mm states. The lens was flipped, and the same procedure was performed for the posterior lens capsule. Results: The precision of the optical system was determined to be +/-0.5um. The resolution is 4um and the sensitivity is 52dB. The human anterior lens capsule thickness was 6.0+/-1.2um unstretched and 4.9+/-0.9um stretched (p=0.008). The human posterior lens capsule was 5.7+/-1.2um unstretched and 5.7+/-1.4um stretched (p=0.974). The monkey anterior lens capsule thickness was 5.9+/-1.9um unstretched and 4.8+/-1.0um stretched (p=0.002). The monkey posterior lens capsule was 5

  18. Nonlinear SVM-DTC for induction motor drive using input-output feedback linearization and high order sliding mode control.

    Science.gov (United States)

    Ammar, Abdelkarim; Bourek, Amor; Benakcha, Abdelhamid

    2017-03-01

    This paper presents a nonlinear Direct Torque Control (DTC) strategy with Space Vector Modulation (SVM) for an induction motor. A nonlinear input-output feedback linearization (IOFL) is implemented to achieve a decoupled torque and flux control and the SVM is employed to reduce high torque and flux ripples. Furthermore, the control scheme performance is improved by inserting a super twisting speed controller in the outer loop and a load torque observer to enhance the speed regulation. The combining of dual nonlinear strategies ensures a good dynamic and robustness against parameters variation and disturbance. The system stability has been analyzed using Lyapunov stability theory. The effectiveness of the control algorithm is investigated by simulation and experimental validation using Matlab/Simulink software with real-time interface based on dSpace 1104. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  19. Bayesian integration and non-linear feedback control in a full-body motor task.

    Directory of Open Access Journals (Sweden)

    Ian H Stevenson

    2009-12-01

    Full Text Available A large number of experiments have asked to what degree human reaching movements can be understood as being close to optimal in a statistical sense. However, little is known about whether these principles are relevant for other classes of movements. Here we analyzed movement in a task that is similar to surfing or snowboarding. Human subjects stand on a force plate that measures their center of pressure. This center of pressure affects the acceleration of a cursor that is displayed in a noisy fashion (as a cloud of dots on a projection screen while the subject is incentivized to keep the cursor close to a fixed position. We find that salient aspects of observed behavior are well-described by optimal control models where a Bayesian estimation model (Kalman filter is combined with an optimal controller (either a Linear-Quadratic-Regulator or Bang-bang controller. We find evidence that subjects integrate information over time taking into account uncertainty. However, behavior in this continuous steering task appears to be a highly non-linear function of the visual feedback. While the nervous system appears to implement Bayes-like mechanisms for a full-body, dynamic task, it may additionally take into account the specific costs and constraints of the task.

  20. Injury profile of non-contact sports for Perak SUKMA athletes | Lee ...

    African Journals Online (AJOL)

    The purpose of this study is to identify the injury profile of non-contact sports among Perak SUKMA athletes. The data from this injury is examined based on the five research questions which are nature of injury, body part, severity of injury (mild, moderate, severe), types of injury (acute or chronic), and factors of injury.

  1. Non-contact detection of pulsed acoustic displacements for the evaluation of sub-surface defects

    NARCIS (Netherlands)

    Bruinsma, A.J.A.

    1987-01-01

    The development of optical methods for detection of ultrasound is important for the technology of non-contact Non-Destructive Evaluation of materials. Several optical methods are limited in their application by their sensitivity for ambient vibrations or their complexity. In this paper a Fiber Time

  2. Quantification of tip-broadening in non-contact atomic force microscopy with carbon nanotube tips

    DEFF Research Database (Denmark)

    Meinander, Kristoffer; Jensen, Thomas N.; Simonsen, Soren B.

    2012-01-01

    Carbon nanotube terminated atomic force microscopy (AFM) probes have been used for the imaging of 5 nm wide surface supported Pt nanoclusters by non-contact (dynamic mode) AFM in an ultra-high vacuum. The results are compared to AFM measurements done with conventional Si-tips, as well...

  3. Using a generalized linear mixed model approach to explore the role of age, motor proficiency, and cognitive styles in children's reach estimation accuracy.

    Science.gov (United States)

    Caçola, Priscila M; Pant, Mohan D

    2014-10-01

    The purpose was to use a multi-level statistical technique to analyze how children's age, motor proficiency, and cognitive styles interact to affect accuracy on reach estimation tasks via Motor Imagery and Visual Imagery. Results from the Generalized Linear Mixed Model analysis (GLMM) indicated that only the 7-year-old age group had significant random intercepts for both tasks. Motor proficiency predicted accuracy in reach tasks, and cognitive styles (object scale) predicted accuracy in the motor imagery task. GLMM analysis is suitable to explore age and other parameters of development. In this case, it allowed an assessment of motor proficiency interacting with age to shape how children represent, plan, and act on the environment.

  4. Secondary seal effects in hydrostatic non-contact seals for reactor coolant pump shaft

    International Nuclear Information System (INIS)

    Fujita, T.; Koga, T.; Tanoue, H.; Hirabayashi, H.

    1987-01-01

    The paper presents a seal flow analysis in a hydrostatic non-contact seal for a PWR coolant pump shaft. A description is given of the non-contact seal for the reactor coolant pump. Results are presented for a distortion analysis of the seal ring, along with the seal flow characteristics and the contact pressure profiles of the secondary seals. The results of the work confirm previously reported findings that the seal ring distortion is sensitive to the o-ring location (which was placed between the ceramic seal face and the seal ring retainer). The paper concludes that the seal flow characteristics and the tracking performance depend upon the dynamic properties of the secondary seal. (U.K.)

  5. Non-Contact Translation-Rotation Sensor Using Combined Effects of Magnetostriction and Piezoelectricity

    Directory of Open Access Journals (Sweden)

    Guang Meng

    2012-10-01

    Full Text Available Precise displacement sensors are an important topic in precision engineering. At present, this type of sensors typically have a single feature of either translation or rotation measurement. They are also inconvenient to integrate with the host devices. In this report we propose a new kind of sensor that enables both translation and rotation measurement by using the combined effect of magnetostriction and piezoelectricity. As a proof of concept, we experimentally realized a prototype of non-contact translation-rotation precise sensor. In the current research stage, through both theoretical and experimental study, the non-contact displacement sensor is shown to be feasible for measuring both translation and rotation either in coarse or fine measurement. Moreover, owing to its compact, rigid structure and fewer components, it can be easily embedded in host equipment.

  6. Non-contact translation-rotation sensor using combined effects of magnetostriction and piezoelectricity.

    Science.gov (United States)

    Yang, Bintang; Liu, Qingwei; Zhang, Ting; Cao, Yudong; Feng, Zhiqiang; Meng, Guang

    2012-10-15

    Precise displacement sensors are an important topic in precision engineering. At present, this type of sensors typically have a single feature of either translation or rotation measurement. They are also inconvenient to integrate with the host devices. In this report we propose a new kind of sensor that enables both translation and rotation measurement by using the combined effect of magnetostriction and piezoelectricity. As a proof of concept, we experimentally realized a prototype of non-contact translation-rotation precise sensor. In the current research stage, through both theoretical and experimental study, the non-contact displacement sensor is shown to be feasible for measuring both translation and rotation either in coarse or fine measurement. Moreover, owing to its compact, rigid structure and fewer components, it can be easily embedded in host equipment.

  7. Contact and non-contact ultrasonic measurement in the food industry: a review

    International Nuclear Information System (INIS)

    Mohd Khairi, Mohd Taufiq; Ibrahim, Sallehuddin; Md Yunus, Mohd Amri; Faramarzi, Mahdi

    2016-01-01

    The monitoring of the food manufacturing process is vital since it determines the safety and quality level of foods which directly affect the consumers’ health. Companies which produce high quality products will gain trust from consumers. This factor helps the companies to make profits. The use of efficient and appropriate sensors for the monitoring process can also reduce cost. The food assessing process based on an ultrasonic sensor has attracted the attention of the food industry due to its excellent capabilities in several applications. The utilization of low or high frequencies for the ultrasonic transducer has provided an enormous benefit for analysing, modifying and guaranteeing the quality of food. The contact and non-contact ultrasonic modes for measurement also contributed significantly to the food processing. This paper presents a review of the application of the contact and non-contact mode of ultrasonic measurement focusing on safety and quality control areas. The results from previous researches are shown and elaborated. (topical review)

  8. Non-Contacting Finger Seals Static Performance Test Results at Ambient and High Temperatures

    Science.gov (United States)

    Proctor, Margaret P.

    2016-01-01

    The non-contacting finger seal is an advanced seal concept with potential to reduce specific fuel consumption in gas turbine engines by 2 to 3 with little to no wear of the seal or rotor. Static performance tests and bind-up tests of eight different non-contacting finger seal configurations were conducted in air at pressure differentials up to 689.4 kPa and temperatures up to 922 K. Four of the seals tested were designed to have lift pads concentric to a herringbone-grooved rotor which generates hydrodynamic lift when rotating. The remaining seals were tested with a smooth rotor; one seal had a circumferential taper and one had an axial taper on the lift pad inner diameter to create hydrodynamic lift during rotation. The effects of the aft finger axial thickness and of the forward finger inner diameter on leakage performance were investigated as well and compared to analytical predictions.

  9. Acanthamoeba keratitis in a non-contact lens wearer with human immunodeficiency virus

    DEFF Research Database (Denmark)

    Hansen, Birgitte Rønde; Kronborg, Gitte

    2003-01-01

    Acanthamoeba keratitis is potentially blinding and often associated with contact lens wearing. A human immunodeficiency virus (HIV)-positive patient, a non-contact lens wearer, presented with keratitis. She experienced a protracted course of disease, characterized by exacerbations and remissions......, and was treated with various topical antibiotics and steroids. 13 months after symptom onset the eye was removed owing to serious scarring of cornea and unbearable pain. Microbiological and histopathological examination of the cornea showed Acanthamoeba. In non-contact lens wearers suffering from Acanthamoeba...... keratitis the diagnosis is delayed, pathognomonic features are often not seen and visual outcome is usually poor. There is no known relation between HIV infection and Acanthamoeba keratitis....

  10. Modeling leukocyte-leukocyte non-contact interactions in a lymph node.

    Directory of Open Access Journals (Sweden)

    Nicola Gritti

    Full Text Available The interaction among leukocytes is at the basis of the innate and adaptive immune-response and it is largely ascribed to direct cell-cell contacts. However, the exchange of a number of chemical stimuli (chemokines allows also non-contact interaction during the immunological response. We want here to evaluate the extent of the effect of the non-contact interactions on the observed leukocyte-leukocyte kinematics and their interaction duration. To this aim we adopt a simplified mean field description inspired by the Keller-Segel chemotaxis model, of which we report an analytical solution suited for slowly varying sources of chemokines. Since our focus is on the non-contact interactions, leukocyte-leukocyte contact interactions are simulated only by means of a space dependent friction coefficient of the cells. The analytical solution of the Keller-Segel model is then taken as the basis of numerical simulations of interactions between leukocytes and their duration. The mean field interaction force that we derive has a time-space separable form and depends on the chemotaxis sensitivity parameter as well as on the chemokines diffusion coefficient and their degradation rate. All these parameters affect the distribution of the interaction durations. We draw a successful qualitative comparison between simulated data and sets of experimental data for DC-NK cells interaction duration and other kinematic parameters. Remarkably, the predicted percentage of the leukocyte-leukocyte interactions falls in the experimental range and depends (~25% increase upon the chemotactic parameter indicating a non-negligible direct effect of the non-contact interaction on the leukocyte interactions.

  11. Acanthamoeba keratitis in a non-contact lens wearer with human immunodeficiency virus

    DEFF Research Database (Denmark)

    Hansen, Birgitte Rønde; Kronborg, Gitte

    2003-01-01

    Acanthamoeba keratitis is potentially blinding and often associated with contact lens wearing. A human immunodeficiency virus (HIV)-positive patient, a non-contact lens wearer, presented with keratitis. She experienced a protracted course of disease, characterized by exacerbations and remissions...... keratitis the diagnosis is delayed, pathognomonic features are often not seen and visual outcome is usually poor. There is no known relation between HIV infection and Acanthamoeba keratitis....

  12. Modeling leukocyte-leukocyte non-contact interactions in a lymph node.

    Science.gov (United States)

    Gritti, Nicola; Caccia, Michele; Sironi, Laura; Collini, Maddalena; D'Alfonso, Laura; Granucci, Francesca; Zanoni, Ivan; Chirico, Giuseppe

    2013-01-01

    The interaction among leukocytes is at the basis of the innate and adaptive immune-response and it is largely ascribed to direct cell-cell contacts. However, the exchange of a number of chemical stimuli (chemokines) allows also non-contact interaction during the immunological response. We want here to evaluate the extent of the effect of the non-contact interactions on the observed leukocyte-leukocyte kinematics and their interaction duration. To this aim we adopt a simplified mean field description inspired by the Keller-Segel chemotaxis model, of which we report an analytical solution suited for slowly varying sources of chemokines. Since our focus is on the non-contact interactions, leukocyte-leukocyte contact interactions are simulated only by means of a space dependent friction coefficient of the cells. The analytical solution of the Keller-Segel model is then taken as the basis of numerical simulations of interactions between leukocytes and their duration. The mean field interaction force that we derive has a time-space separable form and depends on the chemotaxis sensitivity parameter as well as on the chemokines diffusion coefficient and their degradation rate. All these parameters affect the distribution of the interaction durations. We draw a successful qualitative comparison between simulated data and sets of experimental data for DC-NK cells interaction duration and other kinematic parameters. Remarkably, the predicted percentage of the leukocyte-leukocyte interactions falls in the experimental range and depends (~25% increase) upon the chemotactic parameter indicating a non-negligible direct effect of the non-contact interaction on the leukocyte interactions.

  13. Simulation and Experiment Research of Non-contact Micro-liquid Reagent Dispensing

    OpenAIRE

    Yao Yufeng; Lu Shizhou; Liu Yaxin

    2013-01-01

    With the development of biological analytical techniques and high throughput screening techniques, a large number of automated biological agents dispensing systems are widely used in the field of life science research. Non-contact dispensing method characterized by its small dispensing volume, high dispensing precision and quick service speed which satisfies the requirements of biological agent’s distribution, becomes the mainstream dispensing method used in reagent dispensing systems. Howeve...

  14. Non-Contact Circuit for Real-Time Electric and Magnetic Field Measurements

    Science.gov (United States)

    2015-10-01

    s FFT length. Our noise floor is shaped as expected for D-dot sensor, including visible effects from both 1/f noise and our 1-kHz low- pass filter...referred noise spectral density GOTS Government-off-the-shelf IC integrated circuit IIDGWN independently distributed Gaussian white noise LED light...ARL-TR-7507 ● OCT 2015 US Army Research Laboratory Non-Contact Circuit for Real-Time Electric and Magnetic Field Measurements

  15. A non-contact complete knee dislocation with popliteal artery disruption, a rare martial arts injury

    OpenAIRE

    Viswanath, Y; Rogers, I

    1999-01-01

    Complete knee dislocation is a rare injury and an associated incidence of popliteal artery damage ranges from 16-60% of cases. It occurs commonly in road traffic accidents and in high velocity trauma where significant contact remains as the usual mode of injury. We describe a rare case of non-contact knee dislocation with popliteal artery injury sustained while practising Aikido, a type of martial art. This patient successfully underwent closed reduction of the knee with an emergency vein byp...

  16. Non-contact evaluation of milk-based products using air-coupled ultrasound

    Science.gov (United States)

    Meyer, S.; Hindle, S. A.; Sandoz, J.-P.; Gan, T. H.; Hutchins, D. A.

    2006-07-01

    An air-coupled ultrasonic technique has been developed and used to detect physicochemical changes of liquid beverages within a glass container. This made use of two wide-bandwidth capacitive transducers, combined with pulse-compression techniques. The use of a glass container to house samples enabled visual inspection, helping to verify the results of some of the ultrasonic measurements. The non-contact pulse-compression system was used to evaluate agglomeration processes in milk-based products. It is shown that the amplitude of the signal varied with time after the samples had been treated with lactic acid, thus promoting sample destabilization. Non-contact imaging was also performed to follow destabilization of samples by scanning in various directions across the container. The obtained ultrasonic images were also compared to those from a digital camera. Coagulation with glucono-delta-lactone of skim milk poured into this container could be monitored within a precision of a pH of 0.15. This rapid, non-contact and non-destructive technique has shown itself to be a feasible method for investigating the quality of milk-based beverages, and possibly other food products.

  17. Non-Contact Plant Growth Measurement Method and System Based on Ubiquitous Sensor Network Technologies

    Directory of Open Access Journals (Sweden)

    Intae Ryoo

    2011-04-01

    Full Text Available This paper proposes a non-contact plant growth measurement system using infrared sensors based on the ubiquitous sensor network (USN technology. The proposed system measures plant growth parameters such as the stem radius of plants using real-time non-contact methods, and generates diameter, cross-sectional area and thickening form of plant stems using this measured data. Non-contact sensors have been used not to cause any damage to plants during measurement of the growth parameters. Once the growth parameters are measured, they are transmitted to a remote server using the sensor network technology and analyzed in the application program server. The analyzed data are then provided for administrators and a group of interested users. The proposed plant growth measurement system has been designed and implemented using fixed-type and rotary-type infrared sensor based measurement methods and devices. Finally, the system performance is compared and verified with the measurement data that have been obtained by practical field experiments.

  18. Simulation Test System of Non-Contact D-dot Voltage Transformer

    Science.gov (United States)

    Yang, Jie; Wang, Jingang; Luo, Ruixi; Gao, Can; Songnong, Li; Kongjun, Zhou

    2016-04-01

    The development trend of future voltage transformer in smart grid is non-contact measurement, miniaturization and intellectualization. This paper proposes one simulation test system of non-contact D-dot transformer for voltage measurement. This simulation test system consists of D-dot transformer, signal processing circuit and ground PC port. D-dot transformer realizes the indirect voltage measurement by measuring the change rate of electric displacement vector, a non-contact means (He et al. 2004, Principles and experiments of voltage transformer based on self-integrating D-dot probe. Proc CSEE 2014;15:2445-51). Specific to the characteristics of D-dot transformer signals, signal processing circuits with strong resistance to interference and distortion-free amplified sensor output signal are designed. WIFI wireless network is used to transmit the voltage detection to LabVIEW-based ground collection port and LabVIEW technology is adopted for signal reception, data processing and analysis and other functions. Finally, a test platform is established to simulate the performance of the whole test system of single-phase voltage transformer. Test results indicate that this voltage transformer has sound real-time performance, high accuracy and fast response speed and the simulation test system is stable and reliable and can be a new prototype of voltage transformers.

  19. Non-contact radio frequency shielding and wave guiding by multi-folded transformation optics method.

    Science.gov (United States)

    Madni, Hamza Ahmad; Zheng, Bin; Yang, Yihao; Wang, Huaping; Zhang, Xianmin; Yin, Wenyan; Li, Erping; Chen, Hongsheng

    2016-11-14

    Compared with conventional radio frequency (RF) shielding methods in which the conductive coating material encloses the circuits design and the leakage problem occurs due to the gap in such conductive material, non-contact RF shielding at a distance is very promising but still impossible to achieve so far. In this paper, a multi-folded transformation optics method is proposed to design a non-contact device for RF shielding. This "open-shielded" device can shield any object at a distance from the electromagnetic waves at the operating frequency, while the object is still physically open to the outer space. Based on this, an open-carpet cloak is proposed and the functionality of the open-carpet cloak is demonstrated. Furthermore, we investigate a scheme of non-contact wave guiding to remotely control the propagation of surface waves over any obstacles. The flexibilities of such multi-folded transformation optics method demonstrate the powerfulness of the method in the design of novel remote devices with impressive new functionalities.

  20. Non-Contact Stiffness Measurement of a Suspended Single Walled Carbon Nanotube Device

    Science.gov (United States)

    Zheng, Yun; Su, Chanmin; Getty, Stephanie

    2010-01-01

    A new nanoscale electric field sensor was developed for studying triboelectric charging in terrestrial and Martian dust devils. This sensor is capable to measure the large electric fields for large dust devils without saturation. However, to quantify the electric charges and the field strength it is critical to calibrate the mechanical stiffness of the sensor devices. We performed a technical feasibility study of the Nano E-field Sensor stiffness by a non-contact stiffness measurement method. The measurement is based on laser Doppler vibrometer measurement of the thermal noise due to energy flunctuations in the devices. The experiment method provides a novel approach to acquire data that is essential in analyzing the quantitative performance of the E-field Nano Sensor. To carry out the non-contact stiffness measurement, we fabricated a new Single-Walled Carbon Nanotube (SWCNT) E-field sensor with different SWCNTs suspension conditions. The power spectra of the thermal induced displacement in the nano E-field sensor were measured at the accuracy of picometer. The power spectra were then used to derive the mechanical stiffness of the sensors. Effect of suspension conditions on stiffness and sensor sensitivty was discussed. After combined deformation and resistivity measurement, we can compare with our laboratory testing and field testing results. This new non-contact measurement technology can also help to explore to other nano and MEMS devices in the future.

  1. An investigation of highly accurate and precise robotic hole measurements using non-contact devices

    Directory of Open Access Journals (Sweden)

    Usman Zahid

    2016-01-01

    Full Text Available Industrial robots arms are widely used in manufacturing industry because of their support for automation. However, in metrology, robots have had limited application due to their insufficient accuracy. Even using error compensation and calibration methods, robots are not effective for micrometre (μm level metrology. Non-contact measurement devices can potentially enable the use of robots for highly accurate metrology. However, the use of such devices on robots has not been investigated. The research work reported in this paper explores the use of different non-contact measurement devices on an industrial robot. The aim is to experimentally investigate the effects of robot movements on the accuracy and precision of measurements. The focus has been on assessing the ability to accurately measure various geometric and surface parameters of holes despite the inherent inaccuracies of industrial robot. This involves the measurement of diameter, roundness and surface roughness. The study also includes scanning of holes for measuring internal features such as start and end point of a taper. Two different non-contact measurement devices based on different technologies are investigated. Furthermore, effects of eccentricity, vibrations and thermal variations are also assessed. The research contributes towards the use of robots for highly accurate and precise robotic metrology.

  2. Improvement of superconducting cylindrical linear induction motor; Chodendo entogata tan'ichiji rinia yudo mota no tokusei kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Kikuma, T.; Ishiyama, A. [Waseda Univ., Tokyo (Japan)

    2000-05-29

    For the purpose of examining the characteristics (effect of stability and ac loss by the higher harmonic wave etc.) of an alternating current superconductivity winding under a real machine operating environment of the super-conductive AC machine vessel, authors produced a cylindrical shortness first linear guiding motor (SCLIM) which used the NbTi/CuNi super-conducting cable for the first excitation winding experimentally. In this study, the evaluation of the start up thrust and operation confirmation of the quenching detection protection circuit were carried out using the produced SCLIM. In the quenching detection protection control circuit, the first excitation winding was divided into an internal layer and an outer layer, and both layers were excited in the 2 layer division and a quenching detection protection circuit was installed on the 2 layers respectively. The circuit of a part of fact by this of the phase in which the quench was generated and observed was cut off, and the operation would be able to be continued in part of the remainder of the phase and other two phases. Here, it is to cut off the quenched phase from the circuit, when the phase current becomes zero, and the other effect on the phase is held as small as possible. (NEDO)

  3. Modification of The Field-Weakening Control Strategy for Linear Induction Motor Drives Considering The End Effect

    Directory of Open Access Journals (Sweden)

    HAMEDANI, P.

    2015-08-01

    Full Text Available Accurate vector control of a linear induction motor (LIM drive is a complicated subject because of the end effect phenomenon especially in the field-weakening region. This paper concentrates on a novel field-weakening speed control strategy for LIM drive in which the end effect is taken into account. Considering the end effect, new voltage and current limits have been calculated using the Duncan's model. Accordingly, control strategies such as constant force region, partial field-weakening region, and full field-weakening region have been analytically calculated for the first time in this work. In order to improve the control characteristics of the LIM drive, Fuzzy Logic Controller (FLC has been also implemented. Simulation results manifest the satisfactory resultants of the proposed FLC based LIM in the field-weakening region including fast response, no overshoot, negligible steady-state error, and adaptability to load changes. In addition, a new constant force pattern is introduced in this paper by which the reductions of the LIM thrust due to the end effect will be compensated and thus, the current and voltage amplitudes in steady state will remarkably decrease.

  4. Entropic potential field formed for a linear-motor protein near a filament: Statistical-mechanical analyses using simple models

    Science.gov (United States)

    Amano, Ken-ichi; Yoshidome, Takashi; Iwaki, Mitsuhiro; Suzuki, Makoto; Kinoshita, Masahiro

    2010-07-01

    We report a new progress in elucidating the mechanism of the unidirectional movement of a linear-motor protein (e.g., myosin) along a filament (e.g., F-actin). The basic concept emphasized here is that a potential field is entropically formed for the protein on the filament immersed in solvent due to the effect of the translational displacement of solvent molecules. The entropic potential field is strongly dependent on geometric features of the protein and the filament, their overall shapes as well as details of the polyatomic structures. The features and the corresponding field are judiciously adjusted by the binding of adenosine triphosphate (ATP) to the protein, hydrolysis of ATP into adenosine diphosphate (ADP)+Pi, and release of Pi and ADP. As the first step, we propose the following physical picture: The potential field formed along the filament for the protein without the binding of ATP or ADP+Pi to it is largely different from that for the protein with the binding, and the directed movement is realized by repeated switches from one of the fields to the other. To illustrate the picture, we analyze the spatial distribution of the entropic potential between a large solute and a large body using the three-dimensional integral equation theory. The solute is modeled as a large hard sphere. Two model filaments are considered as the body: model 1 is a set of one-dimensionally connected large hard spheres and model 2 is a double helical structure formed by two sets of connected large hard spheres. The solute and the filament are immersed in small hard spheres forming the solvent. The major findings are as follows. The solute is strongly confined within a narrow space in contact with the filament. Within the space there are locations with sharply deep local potential minima along the filament, and the distance between two adjacent locations is equal to the diameter of the large spheres constituting the filament. The potential minima form a ringlike domain in model 1

  5. A descrição do funcionamento de um motor Homopolar linear e suas aplicações: Ilustrando o funcionamento de um acelerador de partículas

    OpenAIRE

    Doff,Adriano; Szmoski,Romeu M.

    2016-01-01

    Neste trabalho exploramos o potencial didático de um motor homopolar linear com o objetivo de ilustrar o princípio de funcionamento de um acelerador de partículas. A fim de estabelecer o mecanismo de funcionamento de um motor homopolar linear, consideramos uma analogia com a descrição de um motor homopolar rotatório, e partir deste apresentamos os princípios de funcionamento deste dispositivo e estabelecemos um limite teórico para a velocidade do motor linear. De posse dos dados gerados exper...

  6. Neonatal non-contact respiratory monitoring based on real-time infrared thermography

    Directory of Open Access Journals (Sweden)

    Abbas Abbas K

    2011-10-01

    Full Text Available Abstract Background Monitoring of vital parameters is an important topic in neonatal daily care. Progress in computational intelligence and medical sensors has facilitated the development of smart bedside monitors that can integrate multiple parameters into a single monitoring system. This paper describes non-contact monitoring of neonatal vital signals based on infrared thermography as a new biomedical engineering application. One signal of clinical interest is the spontaneous respiration rate of the neonate. It will be shown that the respiration rate of neonates can be monitored based on analysis of the anterior naris (nostrils temperature profile associated with the inspiration and expiration phases successively. Objective The aim of this study is to develop and investigate a new non-contact respiration monitoring modality for neonatal intensive care unit (NICU using infrared thermography imaging. This development includes subsequent image processing (region of interest (ROI detection and optimization. Moreover, it includes further optimization of this non-contact respiration monitoring to be considered as physiological measurement inside NICU wards. Results Continuous wavelet transformation based on Debauches wavelet function was applied to detect the breathing signal within an image stream. Respiration was successfully monitored based on a 0.3°C to 0.5°C temperature difference between the inspiration and expiration phases. Conclusions Although this method has been applied to adults before, this is the first time it was used in a newborn infant population inside the neonatal intensive care unit (NICU. The promising results suggest to include this technology into advanced NICU monitors.

  7. Neonatal non-contact respiratory monitoring based on real-time infrared thermography

    Science.gov (United States)

    2011-01-01

    Background Monitoring of vital parameters is an important topic in neonatal daily care. Progress in computational intelligence and medical sensors has facilitated the development of smart bedside monitors that can integrate multiple parameters into a single monitoring system. This paper describes non-contact monitoring of neonatal vital signals based on infrared thermography as a new biomedical engineering application. One signal of clinical interest is the spontaneous respiration rate of the neonate. It will be shown that the respiration rate of neonates can be monitored based on analysis of the anterior naris (nostrils) temperature profile associated with the inspiration and expiration phases successively. Objective The aim of this study is to develop and investigate a new non-contact respiration monitoring modality for neonatal intensive care unit (NICU) using infrared thermography imaging. This development includes subsequent image processing (region of interest (ROI) detection) and optimization. Moreover, it includes further optimization of this non-contact respiration monitoring to be considered as physiological measurement inside NICU wards. Results Continuous wavelet transformation based on Debauches wavelet function was applied to detect the breathing signal within an image stream. Respiration was successfully monitored based on a 0.3°C to 0.5°C temperature difference between the inspiration and expiration phases. Conclusions Although this method has been applied to adults before, this is the first time it was used in a newborn infant population inside the neonatal intensive care unit (NICU). The promising results suggest to include this technology into advanced NICU monitors. PMID:22243660

  8. Continuous non-contact vital sign monitoring in neonatal intensive care unit.

    Science.gov (United States)

    Villarroel, Mauricio; Guazzi, Alessandro; Jorge, João; Davis, Sara; Watkinson, Peter; Green, Gabrielle; Shenvi, Asha; McCormick, Kenny; Tarassenko, Lionel

    2014-09-01

    Current technologies to allow continuous monitoring of vital signs in pre-term infants in the hospital require adhesive electrodes or sensors to be in direct contact with the patient. These can cause stress, pain, and also damage the fragile skin of the infants. It has been established previously that the colour and volume changes in superficial blood vessels during the cardiac cycle can be measured using a digital video camera and ambient light, making it possible to obtain estimates of heart rate or breathing rate. Most of the papers in the literature on non-contact vital sign monitoring report results on adult healthy human volunteers in controlled environments for short periods of time. The authors' current clinical study involves the continuous monitoring of pre-term infants, for at least four consecutive days each, in the high-dependency care area of the Neonatal Intensive Care Unit (NICU) at the John Radcliffe Hospital in Oxford. The authors have further developed their video-based, non-contact monitoring methods to obtain continuous estimates of heart rate, respiratory rate and oxygen saturation for infants nursed in incubators. In this Letter, it is shown that continuous estimates of these three parameters can be computed with an accuracy which is clinically useful. During stable sections with minimal infant motion, the mean absolute error between the camera-derived estimates of heart rate and the reference value derived from the ECG is similar to the mean absolute error between the ECG-derived value and the heart rate value from a pulse oximeter. Continuous non-contact vital sign monitoring in the NICU using ambient light is feasible, and the authors have shown that clinically important events such as a bradycardia accompanied by a major desaturation can be identified with their algorithms for processing the video signal.

  9. A non-contact 3D method to characterize the surface roughness of castings

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat; Hansen, Hans Nørgaard

    2013-01-01

    A non-contact technique using a 3D optical system was used to measure the surface roughness of two selected standard surface roughness comparators used in the foundry industry. Profile and areal analyses were performed using scanning probe image processor (SPIP) software. The results show that th...... and the surface roughness parameter (Sa) values were compared with those of the standards. Sa parameter suffices for the evaluation of casting surface texture. The S series comparators showed a better description of the surface of castings after shot blasting than the A series....

  10. Scanning, non-contact, hybrid broadband diffuse optical spectroscopy and diffuse correlation spectroscopy system

    OpenAIRE

    Johansson, Johannes D.; Mireles, Miguel; Morales-Dalmau, Jordi; Farzam, Parisa; Martínez-Lozano, Mar; Casanovas, Oriol; Durduran, Turgut

    2016-01-01

    A scanning system for small animal imaging using non-contact, hybrid broadband diffuse optical spectroscopy (ncDOS) and diffuse correlation spectroscopy (ncDCS) is presented. The ncDOS uses a two-dimensional spectrophotometer retrieving broadband (610-900 nm) spectral information from up to fifty-seven source-detector distances between 2 and 5 mm. The ncDCS data is simultaneously acquired from four source-detector pairs. The sample is scanned in two dimensions while tracking variations in hei...

  11. Non-contact metrology of aspheric surfaces based on MWLI technology

    Science.gov (United States)

    Berger, G.; Petter, J.

    2013-09-01

    A non-contact optical scanning metrology solution measuring aspheric surfaces is presented, which is based on multi wavelength interferometry (MWLI). The technology yields high density 3D data in short measurement times (including set up time) and provides high, reproducible form measurement accuracy. It measures any asphere without restrictions in terms of spherical departures. In addition, measurement of a large variety of special optics is enabled, such as annular lenses, segmented optics, optics with diffractive steps, ground optics, optics made of opaque and transparent materials, and small and thin optics (e.g. smart phone lenses). The measurement instrument can be used under production conditions.

  12. A non-contact complete knee dislocation with popliteal artery disruption, a rare martial arts injury.

    Science.gov (United States)

    Viswanath, Y K; Rogers, I M

    1999-09-01

    Complete knee dislocation is a rare injury and an associated incidence of popliteal artery damage ranges from 16-60% of cases. It occurs commonly in road traffic accidents and in high velocity trauma where significant contact remains as the usual mode of injury. We describe a rare case of non-contact knee dislocation with popliteal artery injury sustained while practising Aikido, a type of martial art. This patient successfully underwent closed reduction of the knee with an emergency vein bypass graft. Similar injury in association with Aikido has not been described in the English literature previously. Various martial art injuries are briefly discussed and safety recommendations made.

  13. Non-contact local temperature measurement inside an object using an infrared point detector

    Science.gov (United States)

    Hisaka, Masaki

    2017-04-01

    Local temperature measurement in deep areas of objects is an important technique in biomedical measurement. We have investigated a non-contact method for measuring temperature inside an object using a point detector for infrared (IR) light. An IR point detector with a pinhole was constructed and the radiant IR light emitted from the local interior of the object is photodetected only at the position of pinhole located in imaging relation. We measured the thermal structure of the filament inside the miniature bulb using the IR point detector, and investigated the temperature dependence at approximately human body temperature using a glass plate positioned in front of the heat source.

  14. Non-contact angle measurement based on parallel multiplex laser feedback interferometry

    International Nuclear Information System (INIS)

    Zhang Song; Tan Yi-Dong; Zhang Shu-Lian

    2014-01-01

    We present a novel precise angle measurement scheme based on parallel multiplex laser feedback interferometry (PLFI), which outputs two parallel laser beams and thus their displacement difference reflects the angle variation of the target. Due to its ultrahigh sensitivity to the feedback light, PLFI realizes the direct non-contact measurement of non-cooperative targets. Experimental results show that PLFI has an accuracy of 8″ within a range of 1400″. The yaw of a guide is also measured and the experimental results agree with those of the dual-frequency laser interferometer Agilent 5529A. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  15. Long wavelength infrared radiation thermometry for non-contact temperature measurements in gas turbines

    Science.gov (United States)

    Manara, J.; Zipf, M.; Stark, T.; Arduini, M.; Ebert, H.-P.; Tutschke, A.; Hallam, A.; Hanspal, J.; Langley, M.; Hodge, D.; Hartmann, J.

    2017-01-01

    The objective of the EU project "Sensors Towards Advanced Monitoring and Control of Gas Turbine Engines (acronym STARGATE)" is the development of a suite of advanced sensors, instrumentation and related systems in order to contribute to the developing of the next generation of green and efficient gas turbine engines. One work package of the project deals with the design and development of a long wavelength infrared (LWIR) radiation thermometer for the non-contact measurement of the surface temperature of thermal barrier coatings (TBCs) during the operation of gas turbine engines. For opaque surfaces (e.g. metals or superalloys) radiation thermometers which are sensitive in the near or short wavelength infrared are used as state-of-the-art method for non-contact temperature measurements. But this is not suitable for oxide ceramic based TBCs (e.g. partially yttria stabilized zirconia) as oxide ceramics are semi-transparent in the near and short wavelength infrared spectral region. Fortunately the applied ceramic materials are non-transparent in the long wavelength infrared and additionally exhibit a high emittance in this wavelength region. Therefore, a LWIR pyrometer can be used for non-contact temperature measurements of the surfaces of TBCs as such pyrometers overcome the described limitation of existing techniques. For performing non-contact temperature measurements in gas turbines one has to know the infrared-optical properties of the applied TBCs as well as of the hot combustion gas in order to properly analyse the measurement data. For reaching a low uncertainty on the one hand the emittance of the TBC should be high (>0.9) in order to reduce reflections from the hot surrounding and on the other hand the absorbance of the hot combustion gas should be low (pyrometer and the selection of the optimal wavelength band where the detector should be sensitive. Besides determining the spectral infrared-optical properties (emittance, transmittance and absorbance) of the

  16. Speckle-based off-axis holographic detection for non-contact photoacoustic tomography

    Directory of Open Access Journals (Sweden)

    Buj C.

    2015-09-01

    Full Text Available A very fast innovative holographic off-axis non-contact detection method for Photoacoustic Tomography (PAT is introduced. It overcomes the main problems of most state-of-the-art photoacoustic imaging approaches that are long acquisition times and the requirement of acoustic contact. In order to increase the acquisition speed significantly, the surface displacements of the object, caused by the photoacoustic pressure waves, are measured interferometrically in two dimensions. Phase alterations in the observed speckle field are used to identify changes in the object’s topography. A sampling rate of up to 80 MHz is feasible, which reduces the occurrence of motion artefacts.

  17. Dynamic modeling and simulation of an induction motor with adaptive backstepping design of an input-output feedback linearization controller in series hybrid electric vehicle

    Directory of Open Access Journals (Sweden)

    Jalalifar Mehran

    2007-01-01

    Full Text Available In this paper using adaptive backstepping approach an adaptive rotor flux observer which provides stator and rotor resistances estimation simultaneously for induction motor used in series hybrid electric vehicle is proposed. The controller of induction motor (IM is designed based on input-output feedback linearization technique. Combining this controller with adaptive backstepping observer the system is robust against rotor and stator resistances uncertainties. In additional, mechanical components of a hybrid electric vehicle are called from the Advanced Vehicle Simulator Software Library and then linked with the electric motor. Finally, a typical series hybrid electric vehicle is modeled and investigated. Various tests, such as acceleration traversing ramp, and fuel consumption and emission are performed on the proposed model of a series hybrid vehicle. Computer simulation results obtained, confirm the validity and performance of the proposed IM control approach using for series hybrid electric vehicle.

  18. Analysis on the multi-dimensional spectrum of the thrust force for the linear motor feed drive system in machine tools

    Science.gov (United States)

    Yang, Xiaojun; Lu, Dun; Ma, Chengfang; Zhang, Jun; Zhao, Wanhua

    2017-01-01

    The motor thrust force has lots of harmonic components due to the nonlinearity of drive circuit and motor itself in the linear motor feed drive system. What is more, in the motion process, these thrust force harmonics may vary with the position, velocity, acceleration and load, which affects the displacement fluctuation of the feed drive system. Therefore, in this paper, on the basis of the thrust force spectrum obtained by the Maxwell equation and the electromagnetic energy method, the multi-dimensional variation of each thrust harmonic is analyzed under different motion parameters. Then the model of the servo system is established oriented to the dynamic precision. The influence of the variation of the thrust force spectrum on the displacement fluctuation is discussed. At last the experiments are carried out to verify the theoretical analysis above. It can be found that the thrust harmonics show multi-dimensional spectrum characteristics under different motion parameters and loads, which should be considered to choose the motion parameters and optimize the servo control parameters in the high-speed and high-precision machine tools equipped with the linear motor feed drive system.

  19. Proposal of Non-Contact Type Interface of Command Input Using Lip Motion Features

    Science.gov (United States)

    Sato, Yoshiyuki; Kageyama, Yoichi; Nishida, Makoto

    Lip motion features are of practical use in identifying individuals. It is therefore important to develop non-contact type interface. For the interface using lip motion features, individual differences such as accents and dialects in commands should be accepted. In this paper, we propose a method to identify commands by analyzing three kinds of lip motion features. They are lip width, lip length, and ratio of width and length. The analysis is made on the basis of these features' relative values obtained from the primary and object frame. The proposed method has three steps. First, we extracted the lip motion features on the basis of both positions and shapes of lip in each frame of facial images. Second, standard patterns were created from features of six utterances per command. The standard pattern is able to reduce the relative difference in the lip motion features. Third, similarities among commands were computed by Dynamic-Programming (DP) matching. And then, the command with the largest similarity was selected as the target one. Our experimental results suggest that proposed method is useful to construct the non-contact type interface of command input using lip motion features.

  20. Smart Garment Fabrics to Enable Non-Contact Opto-Physiological Monitoring.

    Science.gov (United States)

    Iakovlev, Dmitry; Hu, Sijung; Hassan, Harnani; Dwyer, Vincent; Ashayer-Soltani, Roya; Hunt, Chris; Shen, Jinsong

    2018-03-29

    Imaging photoplethysmography (iPPG) is an emerging technology used to assess microcirculation and cardiovascular signs by collecting backscattered light from illuminated tissue using optical imaging sensors. The aim of this study was to study how effective smart garment fabrics could be capturing physiological signs in a non-contact mode. The present work demonstrates a feasible approach of, instead of using conventional high-power illumination sources, integrating a grid of surface-mounted light emitting diodes (LEDs) into cotton fabric to spotlight the region of interest (ROI). The green and the red LEDs (525 and 660 nm) placed on a small cotton substrate were used to locally illuminate palm skin in a dual-wavelength iPPG setup, where the backscattered light is transmitted to a remote image sensor through the garment fabric. The results show that the illuminations from both wavelength LEDs can be used to extract heart rate (HR) reaching an accuracy of 90% compared to a contact PPG probe. Stretching the fabric over the skin surface alters the morphology of iPPG signals, demonstrating a significantly higher pulsatile amplitude in both channels of green and red illuminations. The skin compression by the fabric could be potentially utilised to enhance the penetration of illumination into cutaneous microvascular beds. The outcome could lead a new avenue of non-contact opto-physiological monitoring and assessment with functional garment fabrics.

  1. Fully-Non-Contact Masking-Based Holography Inspection on Dimensionally Responsive Artwork Materials

    Directory of Open Access Journals (Sweden)

    Vivi Tornari

    2008-12-01

    Full Text Available Environmental control in galleries and museums is a necessity and is informed by the knowledge of ongoing processes of deterioration which can threaten the integrity and stability of artworks. Invisible dimensional changes in many works of art occur following environmental fluctuations as materials respond to the changes in humidity and temperature. The constant influence of dimensional changes usually remains invisible until displacement generates visible deterioration and irreversible damage. This paper exploits fully non contact coherent interferometry in a sequential masking procedure for visualising and studying surface deformation which is the direct effect of dimensional alterations induced by humidity changes. Surface deformation during dimensional displacements of constituent materials may occur on any artwork within an unstable environment. In this context, the presented research study explores the diagnostic potential of fully non contact sensors for the direct structural assessment of environmental effects as they occur in real time on works of art. The method is employed to characterise material responses, complementing and improving understanding of material behaviour in unstable environments.

  2. Non-contact assessment of obstructive sleep apnea cardiovascular biomarkers using photoplethysmography imaging

    Science.gov (United States)

    Amelard, Robert; Pfisterer, Kaylen J.; Jagani, Shubh; Clausi, David A.; Wong, Alexander

    2018-02-01

    Obstructive sleep apnea (OSA) affects 20% of the adult population, and is associated with cardiovascular and cognitive morbidities. However, it is estimated that up to 80% of treatable OSA cases remain undiagnosed. Cur- rent methods for diagnosing OSA are expensive, labor-intensive, and involve uncomfortable wearable sensors. This study explored the feasibility of non-contact biophotonic assessment of OSA cardiovascular biomarkers via photoplethysmography imaging (PPGI). In particular, PPGI was used to monitor the hemodynamic response to obstructive respiratory events. Sleep apnea onset was simulated using Muller's maneuver in which breathing was obstructed by a respiratory clamp. A custom PPGI system, coded hemodynamic imaging (CHI), was positioned 1 m above the bed and illuminated the participant's head with 850 nm light, providing non-intrusive illumination for night-time monitoring. A video was recorded before, during and following an apnea event at 60 fps, yielding 17 ms temporal resolution. Per-pixel absorbance signals were extracted using a Beer-Lambert derived light transport model, and subsequently denoised. The extracted hemodynamic signal exhibited dynamic temporal modulation during and following the apnea event. In particular, the pulse wave amplitude (PWA) decreased during obstructed breathing, indicating vasoconstriction. Upon successful inhalation, the PWA gradually increased toward homeostasis following a temporal phase delay. This temporal vascular tone modulation provides insight into autonomic and vascular response, and may be used to assess sleep apnea using non-contact biophotonic imaging.

  3. Design of novel non-contact multimedia controller for disability by using visual stimulus.

    Science.gov (United States)

    Pan, Jeng-Shyang; Lo, Chi-Chun; Tsai, Shang-Ho; Lin, Bor-Shyh

    2015-12-01

    The design of a novel non-contact multimedia controller is proposed in this study. Nowadays, multimedia controllers are generally used by patients and nursing assistants in the hospital. Conventional multimedia controllers usually involve in manual operation or other physical movements. However, it is more difficult for the disabled patients to operate the conventional multimedia controller by themselves; they might totally depend on others. Different from other multimedia controllers, the proposed system provides a novel concept of controlling multimedia via visual stimuli, without manual operation. The disabled patients can easily operate the proposed multimedia system by focusing on the control icons of a visual stimulus device, where a commercial tablet is used as the visual stimulus device. Moreover, a wearable and wireless electroencephalogram (EEG) acquisition device is also designed and implemented to easily monitor the user's EEG signals in daily life. Finally, the proposed system has been validated. The experimental result shows that the proposed system can effectively measure and extract the EEG feature related to visual stimuli, and its information transfer rate is also good. Therefore, the proposed non-contact multimedia controller exactly provides a good prototype of novel multimedia controlling scheme. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. A Case of Non-Contact Lens related Acanthamoeba keratitis in Malaysia

    Directory of Open Access Journals (Sweden)

    Mohamed Kamel, A. G.

    2005-01-01

    Full Text Available Acanthamoeba is a ubiquitous free-living amoeba and is responsible for an uncommon yet increasingly diagnosed keratitis in humans. Acanthamoeba keratitis is perhaps the most challenging ocular infection to manage successfully and it can result in permanently impaired vision or blindness. Although contact lens use is the principal risk factor, about 10% of cases occur following trauma and exposure to contaminated soil or water. Cases of Acanthamoeba keratitis involving contact lens wearers have previously been reported in Malaysia but this is the first time, a non-contact lens relatedAcanthamoeba keratitis is reported. The case involved a 28 year old Indonesian male construction worker who had a trauma of the right eye. While working his eye was struck by some sand and dust particles and he quickly washed his eye with water from an open tank at the construction site. He then experienced pain, redness, glaring and blurring of vision of the right eye. The diagnosis was missed at the initial presentation but subsequent culture of the corneal scraping demonstrated Acanthamoeba as the aetiological agent. The history, clinical findings, diagnosis and treatment of non-contact lens related Acanthamoeba keratitis are briefly discussed in this communication. We hope to create awareness especially among the medical and paramedical staff about the existence of this infection in the country and fully support the consideration of Acanthamoeba keratitis as part of the differential diagnosis of most cases of presumed microbial keratitis.

  5. Image-based non-contact monitoring of skin texture changed by piloerection for emotion estimation

    Science.gov (United States)

    Uchida, Mihiro; Akaho, Rina; Ogawa, Keiko; Tsumura, Norimichi

    2018-02-01

    In this paper, we find the effective feature values of skin textures captured by non-contact camera to monitor piloerection on the skin for emotion estimation. Recently, emotion estimation is required for service robots to interact with human more naturally. There are a lot of researches of estimating emotion and additional methods are required to improve emotion estimation because using only a few methods may not give enough information for emotion estimation. In the previous study, it is necessary to fix a device on the subject's arm for detecting piloerection, but the contact monitoring can be stress itself and distract the subject from concentrating in the stimuli and evoking strong emotion. So, we focused on the piloerection as the object obtained with non-contact methods. The piloerection is observed as goose bumps on the skin when the subject is emotionally moved, scared and so on. This phenomenon is caused by contraction of arrector pili muscles with the activation of sympathetic nervous system. This piloerection changes skin texture. Skin texture is important in the cosmetic industry to evaluate skin condition. Therefore, we thought that it will be effective to evaluate the condition of skin texture for emotion estimation. The evaluations were performed by extracting the effective feature values from skin textures captured with a high resolution camera. The effective feature values should have high correlation with the degree of piloerection. In this paper, we found that standard deviation of short-line inclination angles in the texture is well correlated with the degree of piloerection.

  6. Development of Non-contact Respiratory Monitoring System for Newborn Using a FG Vision Sensor

    Science.gov (United States)

    Kurami, Yoshiyuki; Itoh, Yushi; Natori, Michiya; Ohzeki, Kazuo; Aoki, Yoshimitsu

    In recent years, development of neonatal care is strongly hoped, with increase of the low-birth-weight baby birth rate. Especially respiration of low-birth-weight baby is incertitude because central nerve and respiratory function is immature. Therefore, a low-birth-weight baby often causes a disease of respiration. In a NICU (Neonatal Intensive Care Unit), neonatal respiration is monitored using cardio-respiratory monitor and pulse oximeter at all times. These contact-type sensors can measure respiratory rate and SpO2 (Saturation of Peripheral Oxygen). However, because a contact-type sensor might damage the newborn's skin, it is a real burden to monitor neonatal respiration. Therefore, we developed the respiratory monitoring system for newborn using a FG (Fiber Grating) vision sensor. FG vision sensor is an active stereo vision sensor, it is possible for non-contact 3D measurement. A respiratory waveform is calculated by detecting the vertical motion of the thoracic and abdominal region with respiration. We attempted clinical experiment in the NICU, and confirmed the accuracy of the obtained respiratory waveform was high. Non-contact respiratory monitoring of newborn using a FG vision sensor enabled the minimally invasive procedure.

  7. Using non-contact therapeutic touch to manage post-surgical pain in the elderly.

    Science.gov (United States)

    McCormack, Guy L

    2009-01-01

    The purpose of this study was to investigate the effects of non-contact therapeutic touch on post-surgical pain in an elderly population receiving occupational therapy in an acute care hospital unit in the United States. Ninety participants were randomly assigned to three groups (experimental, control and placebo) using a three-group experimental pre-test-post-test design and a randomized clinical trial. The experimental group received the non-contact touch intervention, the control group received routine care and the placebo group received the sound of a metronome set at a steady slow pace. Objective measures included the Memorial Pain Scale, the Tellegen Absorption Scale, the Health Attribution Scale and measures of pulse rate and pupil size, which were performed as repeated measures. In the experimental group, 22 out of 30 (73%) demonstrated a statistically significant decrease in pain intensity scores from pre-test to post-test (t [7] = 7.24, p < 0.01) and were better able to participate in occupations. Further research is recommended to replicate this study. 2009 John Wiley & Sons, Ltd

  8. A high-stability non-contact dilatometer for low-amplitude temperature-modulated measurements

    Energy Technology Data Exchange (ETDEWEB)

    Luckabauer, Martin; Sprengel, Wolfgang; Würschum, Roland [Institute of Materials Physics, Graz University of Technology, A-8010 Graz (Austria)

    2016-07-15

    Temperature modulated thermophysical measurements can deliver valuable insights into the phase transformation behavior of many different materials. While especially for non-metallic systems at low temperatures numerous powerful methods exist, no high-temperature device suitable for modulated measurements of bulk metallic alloy samples is available for routine use. In this work a dilatometer for temperature modulated isothermal and non-isothermal measurements in the temperature range from room temperature to 1300 K is presented. The length measuring system is based on a two-beam Michelson laser interferometer with an incremental resolution of 20 pm. The non-contact measurement principle allows for resolving sinusoidal length change signals with amplitudes in the sub-500 nm range and physically decouples the length measuring system from the temperature modulation and heating control. To demonstrate the low-amplitude capabilities, results for the thermal expansion of nickel for two different modulation frequencies are presented. These results prove that the novel method can be used to routinely resolve length-change signals of metallic samples with temperature amplitudes well below 1 K. This high resolution in combination with the non-contact measurement principle significantly extends the application range of modulated dilatometry towards high-stability phase transformation measurements on complex alloys.

  9. A rapid, fully non-contact, hybrid system for generating Lamb wave dispersion curves.

    Science.gov (United States)

    Harb, M S; Yuan, F G

    2015-08-01

    A rapid, fully non-contact, hybrid system which encompasses an air-coupled transducer (ACT) and a laser Doppler vibrometer (LDV) is presented for profiling A0 Lamb wave dispersion of an isotropic aluminum plate. The ACT generates ultrasonic pressure incident upon the surface of the plate. The pressure waves are partially refracted into the plate. The LDV is employed to measure the out-of-plane velocity of the excited Lamb wave mode at some distances where the Lamb waves are formed in the plate. The influence of the ACT angle of incidence on Lamb wave excitation is investigated and Snell's law is used to directly compute Lamb wave dispersion curves including phase and group velocity dispersion curves in aluminum plates from incident angles found to generate optimal A0 Lamb wave mode. The measured curves are compared to results obtained from a two-dimensional (2-D) Fast Fourier transform (FFT), Morlet wavelet transform (MWT) and theoretical predictions. It was concluded that the experimental results obtained using Snell's law concept are well in accordance with the theoretical solutions. The high degree of accuracy in the measured data with the theoretical results proved a high sensitivity of the air-coupled and laser ultrasound in characterizing Lamb wave dispersion in plate-like structures. The proposed non-contact hybrid system can effectively characterize the dispersive relation without knowledge of neither the materials characteristics nor the mathematical model. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Performance of Magnetic-Superconductor Non-Contact Harmonic Drive for Cryogenic Space Applications

    Directory of Open Access Journals (Sweden)

    Jose Luis Perez-Diaz

    2015-07-01

    Full Text Available Harmonic drives are profusely used in aerospace mainly because of their compactness and large reduction ratio. However, their use in cryogenic environments is still a challenge. Lubrication and fatigue are non-trivial issues under these conditions. The objective of the Magnetic-Superconductor Cryogenic Non-contact Harmonic Drive (MAGDRIVE project, funded by the EU Space FP7, is to design, build, and test a new concept of MAGDRIVE. Non-contact interactions among magnets, soft magnetic materials, and superconductors are efficiently used to provide a high reduction ratio gear that smoothly and naturally operates at cryogenic environments. The limiting elements of conventional harmonic drives (teeth, flexspline, and ball bearings are substituted by contactless mechanical components (magnetic gear and superconducting magnetic bearings. The absence of contact between moving parts prevents wear, lubricants are no longer required, and the operational lifetime is greatly increased. This is the first mechanical reducer in mechanical engineering history without any contact between moving parts. In this paper, the test results of a −1:20 inverse reduction ratio MAGDRIVE prototype are reported. In these tests, successful operation at 40 K and 10−3 Pa was demonstrated for more than 1.5 million input cycles. A maximum torque of 3 N·m and an efficiency of 80% were demonstrated. The maximum tested input speed was 3000 rpm, six times the previous existing record for harmonic drives at cryogenic temperatures.

  11. Diode laser-induced tissue effects: in vitro tissue model study and in vivo evaluation of wound healing following non-contact application.

    Science.gov (United States)

    Havel, Miriam; Betz, Christian S; Leunig, Andreas; Sroka, Ronald

    2014-08-01

    The basic difference between the various common medical laser systems is the wavelength of the emitted light, leading to altered light-tissue interactions due to the optical parameters of the tissue. This study examines laser induced tissue effects in an in vitro tissue model using 1,470 nm diode laser compared to our standard practice for endonasal applications (940 nm diode laser) under standardised and reproducible conditions. Additionally, in vivo induced tissue effects following non-contact application with focus on mucosal healing were investigated in a controlled intra-individual design in patients treated for hypertrophy of nasal turbinate. A certified diode laser system emitting the light of λ = 1470 nm was evaluated with regards to its tissue effects (ablation, coagulation) in an in vitro setup on porcine liver and turkey muscle tissue model. To achieve comparable macroscopic tissue effects the laser fibres (600 µm core diameter) were fixed to a computer controlled stepper motor and the laser light was applied in a reproducible procedure under constant conditions. For the in vivo evaluation, 20 patients with nasal obstruction due to hyperplasia of inferior nasal turbinates were included in this prospective randomised double-blinded comparative trial. The endoscopic controlled endonasal application of λ = 1470 nm on the one and λ = 940 nm on the other side, both in 'non-contact' mode, was carried out as an outpatient procedure under local anaesthesia. The postoperative wound healing process (mucosal swelling, scab formation, bleeding, infection) was endoscopically documented and assessed by an independent physician. In the experimental setup, the 1,470 nm laser diode system proved to be efficient in inducing tissue effects in non-contact mode with a reduced energy factor of 5-10 for highly perfused liver tissue to 10-20 for muscle tissue as compared to the 940 nm diode laser system. In the in vivo evaluation scab formation

  12. A Research Based on the metering and detecting Device for Industrial dispenser of non-contact technology

    Science.gov (United States)

    Chen, Xin; Li, Jingjing; Wang, Jingying

    2017-12-01

    Based on the non-contact detection technology, for the needs of on-site measurement for industrial dispenser, the dispenser device is designed and utilized non-contact laser measuring technology with high precision for measurement of length and speed to measure the coordination of displacement stroke and speed. According to “GBT 26799-2011 technical conditions for General Dispenser”, several key parameters are detected by comparing the experimental results, to meet the metering requirements of industrial dispenser.

  13. Control de velocidad del motor de indución empleando linealización por realimentación de estados Speed control of induction motor using state feedback linearization

    Directory of Open Access Journals (Sweden)

    Eduardo Giraldo Suárez

    2009-01-01

    Full Text Available Este documento presenta la aplicación de la técnica de control no lineal clásica llamada linealización por realimentación de variables de estado. Se hace una aplicación en el motor de inducción, la variable a controlar es la velocidad del eje del motor, el sistema emplea el esquema de control vectorial para máquinas de corriente alterna desarrollado en las últimas décadas; este método es análogo a la técnica de control del motor de corriente directa. El modelo del motor de inducción se describe en el sistema de coordenadas de campo orientado del flujo de rotor y se muestra una introducción al producto y la derivada de Lie, empleados en el diseño del controlador no lineal.This articles shows the application of a classic non-linear control technique called "linearization by feedback of status variables." An application on the induction engine is made. Variable to be controlled is speed of the engine shaft. The system employs a vectorial control scheme for AC engines developed during the last decades. This is a method analogous to the DC engine control technique. Induction engine model is described in the guided field coordinate system of rotor flow. Introduction to the product and Lie derivative used for designing the non-linear controller are shown.

  14. Patient characteristics, diagnosis, and treatment of non-contact lens related Acanthamoeba keratitis.

    Science.gov (United States)

    Sharma, S; Garg, P; Rao, G N

    2000-10-01

    To review the clinical characteristics, diagnosis, and visual outcome in patients with non-contact lens related Acanthamoeba keratitis and compare the findings with reported series of contact lens associated Acanthamoeba keratitis. Medical and microbiology records of 39 consecutive patients with a diagnosis of Acanthamoeba keratitis, at a tertiary eyecare centre in India between January 1996 and June 1998, were analysed retrospectively. A majority of the patients presented with poor visual acuity and large corneal stromal infiltrates (mean size 38.20 (SD 26. 18) mm). A predisposing factor was elicited in 19/39 (48.7%) patients (trauma 15, dirty water splash three, leaf juice one). None of the patients had worn contact lenses. Most patients (26/39 (66. 6%)) came from a low socioeconomic background. Complaint of severe pain was not a significant feature and radial keratoneuritis was seen in 1/39 (2.5%) patients. A ring infiltrate was present in 41.1% of cases. A clinical diagnosis of fungal keratitis was made in 45% of the patients before they were seen by us. However, all patients were diagnosed microbiologically at our institute based on demonstration of Acanthamoeba cysts in corneal scrapings (34/39) and/or culture of Acanthamoeba (34/39). Treatment with biguanides (PHMB, 15/38 (39.4%), PHMB with CHx, 23/38 (60.5%), one patient did not return for treatment) resulted in healing with scar formation in 27 out of 31(87.0%) followed up patients (mean time to healing 106.9 days). Overall visual outcome was poor with no statistical difference between cases diagnosed within 30 days (early) or 30 days after (late) start of symptoms. The visual outcome in cases requiring tissue adhesive (five) and keratoplasty (three) was also poor. This is thought to be the largest series of cases of Acanthamoeba keratitis in non-contact lens wearers. In such cases, the disease is advanced at presentation in most patients, pathognomonic clinical features are often not seen, disease

  15. Investigation of the Sintering Process Using Non-Contact Electromagnetic Acoustic Transducers

    Energy Technology Data Exchange (ETDEWEB)

    James C. Foley; David K. Rehbein; Daniel J. Barnard

    2001-05-30

    In-situ characterizations of green state part density and sintering state have long been desired in the powder metal community. Recent advances in non-contact electromagnetic acoustic transducer (EMAT) technology have enabled in-situ monitoring of acoustic amplitude and velocity as sintering proceeds. Samples were made from elemental powders of Al (99.99%), Al (99.7%), Ag, (99.99%), Cu (99.99%) and Fe (99.9%). The powders were pressed in a uniaxial die and examined with acoustic waves for changes in velocity and amplitude during sintering for the samples containing Al, Ag, and Cu. The changes in acoustic properties were correlated with sample microstructures and mechanical properties. Evolution of a series of reverberating echoes during sintering is shown to provide information on the state of sintering, and changes in sintering kinetics as well as having the potential for detection of interior flaws.

  16. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

    Science.gov (United States)

    Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

    2015-11-01

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants.

  17. Plate-shaped non-contact ultrasonic transporter using flexural vibration.

    Science.gov (United States)

    Ishii, Takahiko; Mizuno, Yosuke; Koyama, Daisuke; Nakamura, Kentaro; Harada, Kana; Uchida, Yukiyoshi

    2014-02-01

    We developed a plate-shaped non-contact transporter based on ultrasonic vibration, exploiting a phenomenon that a plate can be statically levitated at the place where its gravity and the acoustic radiation force are balanced. In the experiment, four piezoelectric zirconate titanate elements were attached to aluminum plates, on which lattice flexural vibration was excited at 22.3 kHz. The vibrating plates were connected to a loading plate via flexible posts that can minimize the influence of the flexure induced by heavy loads. The distribution of the vibration displacement on the plate was predicted through finite-element analysis to find the appropriate positions of the posts. The maximum levitation height of this transporter was 256 μm with no load. When two vibrating plates were connected to a loading plate, the maximum transportable load was 4.0 kgf. Copyright © 2013. Published by Elsevier B.V.

  18. Non-contact optical sensor for detection of glucose concentration using a magneto-optic effect

    Science.gov (United States)

    Ozana, Nisan; Beiderman, Yevgeny; Anand, Arun; Javidi, Baharam; Polani, Sagi; Schwarz, Ariel; Shemer, Amir; García, Javier; Zalevsky, Zeev

    2016-03-01

    In this paper we aim to experimentally verify a speckle based technique for non-contact measurement of glucose concentration in blood stream while the vision for the final device aims to contain a single wristwatch-style device containing an AC (alternating) electro-magnet generated by a solenoid, a laser and a camera. The experiments presented in work are performed in-vitro in order to verify the effects that are responsible for the operation principle. When a glucose substance is inserted into a solenoid generating an alternating magnetic field it exhibits Faraday rotation which affects the temporal changes of the secondary speckle patterns distribution. The temporal frequency resulting from the AC magnetic field was found to have a lock-in amplification role which increased the observability of the relatively small magneto-optic effect. Experimental results to support the proposed concept are presented.

  19. Sub-Angstrom oscillation amplitude non-contact atomic force microscopy for lateral force gradient measurement

    International Nuclear Information System (INIS)

    Atabak, Mehrdad; Unverdi, Ozhan; Ozer, H. Ozguer; Oral, Ahmet

    2009-01-01

    We report the first results from novel sub-Angstrom oscillation amplitude non-contact atomic force microscopy developed for lateral force gradient measurements. Quantitative lateral force gradients between a tungsten tip and Si(1 1 1)-(7 x 7) surface can be measured using this microscope. Simultaneous lateral force gradient and scanning tunnelling microscope images of single and multi atomic steps are obtained. In our measurement, tunnel current is used as feedback. The lateral stiffness contrast has been observed to be 2.5 N/m at single atomic step, in contrast to 13 N/m at multi atomic step on Si(1 1 1) surface. We also carried out a series of lateral stiffness-distance spectroscopy. We observed lateral stiffness-distance curves exhibit sharp increase in the stiffness as the sample is approached towards the surface. We usually observed positive stiffness and sometimes going into slightly negative region.

  20. Investigation of human body potential measured by a non-contact measuring system.

    Science.gov (United States)

    Ichikawa, Norimitsu

    2016-12-07

    A human body is occasionally electrified in a room. This charged object will be a source of electrostatic accidents, including the malfunction of electronic equipment. Hence, prevention of these accidents is required. Accidents occasionally occur, even though antistatic clothes and shoes are used. One of the causes for these accidents is that there is a lack of the preventive measures. This situation occurs when using, for example, unconductive wax. In this study, human body potential (voltage) is measured using a non-contact measuring system. An investigation of the human body's voltage when using this system is conducted. The result demonstrates that the voltage of a human body wearing antistatic clothes and shoes or light clothes and slippers exceeds a malfunctioning voltage of a microelectronics device when the body walks on floors. Thus, accidents may occur even if a human body wearing the antistatic clothes walks on flooring. These results will be useful in estimating determination whether electrostatic accidents occur or not.

  1. A comparison of hamstring muscle activity during different screening tests for non-contact ACL injury

    DEFF Research Database (Denmark)

    Husted, Rasmus S; Bencke, Jesper; Andersen, Lars Louis

    2016-01-01

    BACKGROUND: Reduced ability to activate the medial hamstring muscles during a sports-specific sidecutting movement has been found to be a potential risk factor for non-contact ACL injury. However, whether a reduced ability to activate the medial hamstring muscle is a general neuromuscular...... phenomenon and thereby observable independently of the type of clinical screening tests used is not known. This cross sectional study investigated the rank correlation of knee joint neuromuscular activity between three different ACL injury risk screening tests. METHODS: Sixty-two adolescent female elite...... football and handball players (16.7±1.3years) participated in the study. Using surface electromyography (EMG) assessment, the neuromuscular activity of medial hamstring muscle (semitendinosus, ST), lateral hamstring muscle (biceps femoris, BF) and quadriceps muscle (vastus lateralis, VL) were monitored...

  2. A non-contact complete knee dislocation with popliteal artery disruption, a rare martial arts injury

    Science.gov (United States)

    Viswanath, Y; Rogers, I

    1999-01-01

    Complete knee dislocation is a rare injury and an associated incidence of popliteal artery damage ranges from 16-60% of cases. It occurs commonly in road traffic accidents and in high velocity trauma where significant contact remains as the usual mode of injury. We describe a rare case of non-contact knee dislocation with popliteal artery injury sustained while practising Aikido, a type of martial art. This patient successfully underwent closed reduction of the knee with an emergency vein bypass graft. Similar injury in association with Aikido has not been described in the English literature previously. Various martial art injuries are briefly discussed and safety recommendations made.


Keywords: Aikido; knee dislocation; popliteal artery disruption; sports injury PMID:10616692

  3. A real-time non-contact monitoring method of subsea pipelines

    Directory of Open Access Journals (Sweden)

    Song Dalei

    2015-01-01

    Full Text Available To monitoring the subsea pipeline in real-time, a special potentiometric sensor array and a potential prediction model are presented in this paper. Firstly, to measure the potential of seawater, a special potentiometric sensor array with Ag/AgCl all-solid-state reference electrodes is first developed in this paper. Secondly, according to the obtained distribution law of electric field intensities a prediction model of the pipeline potentials is developed. Finally, the potentiometric sensor array is applied in sink experiment and the prediction model is validated by the sink measurements. The maximum error for pipeline potential prediction model is 1.1 mV. The proposed non-contact monitoring method for subsea pipeline can predict the potential of sea pipeline in real-time, thus providing important information for further subsea pipeline maintenance.

  4. Non-contact excitation of fundamental resonance frequencies of an asphalt concrete specimen

    Science.gov (United States)

    Gudmarsson, Anders; Ryden, Nils; Birgisson, Björn

    2015-03-01

    Impact hammer and non-contact speaker excitation were applied to an asphalt concrete, a PVC-U and a concrete specimen to measure the fundamental longitudinal resonance frequency at different strain levels. The impact and the noncontact excitation methods resulted in similar resonance frequencies for the undamaged asphalt concrete and for the PVC-U specimen. However, the two excitation approaches gave different results for the concrete specimen, which was shown to have a nonlinear response to increasing strain levels. A reduction and a following recovery of the resonance frequency of the asphalt concrete were shown after the specimen was exposed to a small amount of damage. However, no fast nonlinear dynamics were observed for the asphalt concrete through the speaker measurements.

  5. Magnetic induction spectroscopy: non-contact measurement of the electrical conductivity spectra of biological samples

    International Nuclear Information System (INIS)

    Barai, A; Watson, S; Patz, R; Griffiths, H

    2012-01-01

    Measurement of the electrical conductivity of biological tissues as a function of frequency, often termed ‘bioelectrical impedance spectroscopy (BIS)’, provides valuable information on tissue structure and composition. In implementing BIS though, there can be significant practical difficulties arising from the electrode–sample interface which have likely limited its deployment in industrial applications. In magnetic induction spectroscopy (MIS) these difficulties are eliminated through the use of fully non-contacting inductive coupling between the sensors and sample. However, inductive coupling introduces its own set of technical difficulties, primarily related to the small magnitudes of the induced currents and their proportionality with frequency. This paper describes the design of a practical MIS system incorporating new, highly-phase-stable electronics and compares its performance with that of electrode-based BIS in measurements on biological samples including yeast suspensions in saline (concentration 50–400 g l −1 ) and solid samples of potato, cucumber, tomato, banana and porcine liver. The shapes of the MIS spectra were in good agreement with those for electrode-based BIS, with a residual maximum discrepancy of 28%. The measurement precision of the MIS was 0.05 S m −1 at 200 kHz, improving to 0.01 S m −1 at a frequency of 20 MHz, for a sample volume of 80 ml. The data-acquisition time for each MIS measurement was 52 s. Given the value of spectroscopic conductivity information and the many advantages of obtaining these data in a non-contacting manner, even through electrically-insulating packaging materials if necessary, it is concluded that MIS is a technique with considerable potential for monitoring bio-industrial processes and product quality. (paper)

  6. Study and Experiment on Non-Contact Voltage Sensor Suitable for Three-Phase Transmission Line.

    Science.gov (United States)

    Zhou, Qiang; He, Wei; Xiao, Dongping; Li, Songnong; Zhou, Kongjun

    2015-12-30

    A voltage transformer, as voltage signal detection equipment, plays an important role in a power system. Presently, more and more electric power systems are adopting potential transformer and capacitance voltage transformers. Transformers are often large in volume and heavyweight, their insulation design is difficult, and an iron core or multi-grade capacitance voltage division structure is generally adopted. As a result, the detection accuracy of transformer is reduced, a huge phase difference exists between detection signal and voltage signal to be measured, and the detection signal cannot accurately and timely reflect the change of conductor voltage signal to be measured. By aiming at the current problems of electric transformation, based on electrostatic induction principle, this paper designed a non-contact voltage sensor and gained detection signal of the sensor through electrostatic coupling for the electric field generated by electric charges of the conductor to be measured. The insulation structure design of the sensor is simple and its volume is small; phase difference of sensor measurement is effectively reduced through optimization design of the electrode; and voltage division ratio and measurement accuracy are increased. The voltage sensor was tested on the experimental platform of simulating three-phase transmission line. According to the result, the designed non-contact voltage sensor can realize accurate and real-time measurement for the conductor voltage. It can be applied to online monitoring for the voltage of three-phase transmission line or three-phase distribution network line, which is in accordance with the development direction of the smart grid.

  7. Study and Experiment on Non-Contact Voltage Sensor Suitable for Three-Phase Transmission Line

    Directory of Open Access Journals (Sweden)

    Qiang Zhou

    2015-12-01

    Full Text Available A voltage transformer, as voltage signal detection equipment, plays an important role in a power system. Presently, more and more electric power systems are adopting potential transformer and capacitance voltage transformers. Transformers are often large in volume and heavyweight, their insulation design is difficult, and an iron core or multi-grade capacitance voltage division structure is generally adopted. As a result, the detection accuracy of transformer is reduced, a huge phase difference exists between detection signal and voltage signal to be measured, and the detection signal cannot accurately and timely reflect the change of conductor voltage signal to be measured. By aiming at the current problems of electric transformation, based on electrostatic induction principle, this paper designed a non-contact voltage sensor and gained detection signal of the sensor through electrostatic coupling for the electric field generated by electric charges of the conductor to be measured. The insulation structure design of the sensor is simple and its volume is small; phase difference of sensor measurement is effectively reduced through optimization design of the electrode; and voltage division ratio and measurement accuracy are increased. The voltage sensor was tested on the experimental platform of simulating three-phase transmission line. According to the result, the designed non-contact voltage sensor can realize accurate and real-time measurement for the conductor voltage. It can be applied to online monitoring for the voltage of three-phase transmission line or three-phase distribution network line, which is in accordance with the development direction of the smart grid.

  8. Non-contact ulcer area calculation system for neuropathic foot ulcer.

    Science.gov (United States)

    Shah, Parth; Mahajan, Siddaram; Nageswaran, Sharmila; Paul, Sathish Kumar; Ebenzer, Mannam

    2017-08-11

    Around 125,785 new cases in year 2013-14 of leprosy were detected in India as per WHO report on leprosy in September 2015 which accounts to approximately 62% of the total new cases. Anaesthetic foot caused by leprosy leads to uneven loading of foot leading to ulcer in approximately 20% of the cases. Much efforts have gone in identifying newer techniques to efficiently monitor the progress of ulcer healing. Current techniques followed in measuring the size of ulcers, have not been found to be so accurate but are still is followed by clinicians across the globe. Quantification of prognosis of the condition would be required to understand the efficacy of current treatment methods and plan for further treatment. This study aims at developing a non contact technique to precisely measure the size of ulcer in patients affected by leprosy. Using MATLAB software, GUI was designed to process the acquired ulcer image by segmenting and calculating the pixel area of the image. The image was further converted to a standard measurement using a reference object. The developed technique was tested on 16 ulcer images acquired from 10 leprosy patients with plantar ulcers. Statistical analysis was done using MedCalc analysis software to find the reliability of the system. The analysis showed a very high correlation coefficient (r=0.9882) between the ulcer area measurements done using traditional technique and the newly developed technique, The reliability of the newly developed technique was significant with a significance level of 99.9%. The designed non-contact ulcer area calculating system using MATLAB is found to be a reliable system in calculating the size of ulcers. The technique would help clinicians have a reliable tool to monitor the progress of ulcer healing and help modify the treatment protocol if needed. Copyright © 2017 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  9. A comparison of hamstring muscle activity during different screening tests for non-contact ACL injury.

    Science.gov (United States)

    Husted, Rasmus S; Bencke, Jesper; Andersen, Lars L; Myklebust, Grethe; Kallemose, Thomas; Lauridsen, Hanne B; Hölmich, Per; Aagaard, Per; Zebis, Mette K

    2016-06-01

    Reduced ability to activate the medial hamstring muscles during a sports-specific sidecutting movement has been found to be a potential risk factor for non-contact ACL injury. However, whether a reduced ability to activate the medial hamstring muscle is a general neuromuscular phenomenon and thereby observable independently of the type of clinical screening tests used is not known. This cross sectional study investigated the rank correlation of knee joint neuromuscular activity between three different ACL injury risk screening tests. Sixty-two adolescent female elite football and handball players (16.7±1.3years) participated in the study. Using surface electromyography (EMG) assessment, the neuromuscular activity of medial hamstring muscle (semitendinosus, ST), lateral hamstring muscle (biceps femoris, BF) and quadriceps muscle (vastus lateralis, VL) were monitored during three standardized screening tests - i.e. one-legged horizontal hop (OLH), drop vertical jump (DJ) and sidecutting (SC). Neuromuscular pre-activity was measured in the time interval 10ms prior to initial contact on a force plate. For neuromuscular hamstring muscle pre-activity, correlation analysis (Spearman correlation coefficient) showed low-to-moderate correlations between SC and 1) DJ (rs=0.34-0.36, Phamstring pre-activity share some common variance during the examined tests. However, a lack of strong correlation suggests that we cannot generalize one risk factor during one test to another test. The present data demonstrate that one-legged horizontal hop and drop vertical jump testing that are commonly used in the clinical setting does not resemble the specific neuromuscular activity patterns known to exist during sidecutting, a well known high risk movement for non-contact ACL injury. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Modal analysis of a loaded tire with non-contact measurements and piezoelectric excitation

    Science.gov (United States)

    Ferhat, Ipar; Tarazaga, Pablo A.

    2017-04-01

    The complex nature of tires requires very precise test data to model the structure accurately. The highly damped characteristics, geometric features and operational conditions of tires cause various testing difficulties that affect the reliability of the modal testing. One of the biggest challenges of tire testing is exciting the whole tire at once. Conventionally, impact hammers, shakers, and cleats are used as an excitation input. The shortcomings of these excitation methods are the directional and force inconsistency of hammer impacts, coupled dynamics of shakers and speed limitations of cleat excitation. Other challenges of modal testing of tires are the effect of added mass due to sensor placements and difficulty of vibration measurement of a rotating tire with accelerometers. In order to remedy these problems, we conduct experimental modal analysis (EMA) using a non-contact measurement technique and piezoelectric excitation. For non-contact measurement, a 3-D scanning laser doppler vibrometer (SLDV) is used. For the piezoelectric excitation, Micro Fiber Composite (MFC) patches are used due to their flexible nature and power capacity. This excitation method can also be crucial to the excitation of rotating tires since the cleat excitation is not adequate for low-speed measurements. Furthermore, the piezoelectric actuation could be used as sensors as well as noise controllers in operating conditions. For this work, we run experiments for a loaded tire in non-rotating condition. Experiments are carried out for the frequency bandwidth up to 500Hz to capture the structural behavior under high-frequency excitations and its potential coupled behavior to airborne noise.

  11. DistancePPG: Robust non-contact vital signs monitoring using a camera

    Science.gov (United States)

    Kumar, Mayank; Veeraraghavan, Ashok; Sabharwal, Ashutosh

    2015-01-01

    Vital signs such as pulse rate and breathing rate are currently measured using contact probes. But, non-contact methods for measuring vital signs are desirable both in hospital settings (e.g. in NICU) and for ubiquitous in-situ health tracking (e.g. on mobile phone and computers with webcams). Recently, camera-based non-contact vital sign monitoring have been shown to be feasible. However, camera-based vital sign monitoring is challenging for people with darker skin tone, under low lighting conditions, and/or during movement of an individual in front of the camera. In this paper, we propose distancePPG, a new camera-based vital sign estimation algorithm which addresses these challenges. DistancePPG proposes a new method of combining skin-color change signals from different tracked regions of the face using a weighted average, where the weights depend on the blood perfusion and incident light intensity in the region, to improve the signal-to-noise ratio (SNR) of camera-based estimate. One of our key contributions is a new automatic method for determining the weights based only on the video recording of the subject. The gains in SNR of camera-based PPG estimated using distancePPG translate into reduction of the error in vital sign estimation, and thus expand the scope of camera-based vital sign monitoring to potentially challenging scenarios. Further, a dataset will be released, comprising of synchronized video recordings of face and pulse oximeter based ground truth recordings from the earlobe for people with different skin tones, under different lighting conditions and for various motion scenarios. PMID:26137365

  12. The numerical assessment of motion strategies for integrated linear motor during starting of a free-piston engine generator

    Science.gov (United States)

    Razali Hanipah, M.; Razul Razali, Akhtar

    2017-10-01

    Free-piston engine generator (FPEG) provides a novel method for electrical power generation in hybrid electric vehicle applications with scarcely reported prototype development and testing. This paper is looking into the motion control strategy for motoring the FPEG during starting. There are two motion profiles investigated namely, trapezoidal velocity and Scurve velocity. Both motion profiles were investigated numerically and the results have shown that the S-curve motion can only achieve 80% of the stroke when operated at the proposed motoring speed of 10Hz.

  13. Balancing Vibrations at Harmonic Frequencies by Injecting Harmonic Balancing Signals into the Armature of a Linear Motor/Alternator Coupled to a Stirling Machine

    Science.gov (United States)

    Holliday, Ezekiel S. (Inventor)

    2014-01-01

    Vibrations at harmonic frequencies are reduced by injecting harmonic balancing signals into the armature of a linear motor/alternator coupled to a Stirling machine. The vibrations are sensed to provide a signal representing the mechanical vibrations. A harmonic balancing signal is generated for selected harmonics of the operating frequency by processing the sensed vibration signal with adaptive filter algorithms of adaptive filters for each harmonic. Reference inputs for each harmonic are applied to the adaptive filter algorithms at the frequency of the selected harmonic. The harmonic balancing signals for all of the harmonics are summed with a principal control signal. The harmonic balancing signals modify the principal electrical drive voltage and drive the motor/alternator with a drive voltage component in opposition to the vibration at each harmonic.

  14. Partially non-linear stimulation intensity-dependent effects of direct current stimulation on motor cortex excitability in humans.

    Science.gov (United States)

    Batsikadze, G; Moliadze, V; Paulus, W; Kuo, M-F; Nitsche, M A

    2013-04-01

    Transcranial direct current stimulation (tDCS) of the human motor cortex at an intensity of 1 mA with an electrode size of 35 cm(2) has been shown to induce shifts of cortical excitability during and after stimulation. These shifts are polarity-specific with cathodal tDCS resulting in a decrease and anodal stimulation in an increase of cortical excitability. In clinical and cognitive studies, stronger stimulation intensities are used frequently, but their physiological effects on cortical excitability have not yet been explored. Therefore, here we aimed to explore the effects of 2 mA tDCS on cortical excitability. We applied 2 mA anodal or cathodal tDCS for 20 min on the left primary motor cortex of 14 healthy subjects. Cathodal tDCS at 1 mA and sham tDCS for 20 min was administered as control session in nine and eight healthy subjects, respectively. Motor cortical excitability was monitored by transcranial magnetic stimulation (TMS)-elicited motor-evoked potentials (MEPs) from the right first dorsal interosseous muscle. Global corticospinal excitability was explored via single TMS pulse-elicited MEP amplitudes, and motor thresholds. Intracortical effects of stimulation were obtained by cortical silent period (CSP), short latency intracortical inhibition (SICI) and facilitation (ICF), and I wave facilitation. The above-mentioned protocols were recorded both before and immediately after tDCS in randomized order. Additionally, single-pulse MEPs, motor thresholds, SICI and ICF were recorded every 30 min up to 2 h after stimulation end, evening of the same day, next morning, next noon and next evening. Anodal as well as cathodal tDCS at 2 mA resulted in a significant increase of MEP amplitudes, whereas 1 mA cathodal tDCS decreased corticospinal excitability. A significant shift of SICI and ICF towards excitability enhancement after both 2 mA cathodal and anodal tDCS was observed. At 1 mA, cathodal tDCS reduced single-pulse TMS-elicited MEP amplitudes and shifted SICI

  15. Reliability of the non-contact tono-pachymeter Tonopachy NT-530P in healthy eyes.

    Science.gov (United States)

    García-Resúa, Carlos; Pena-Verdeal, Hugo; Miñones, Mercedes; Giraldez, M Jesus; Yebra-Pimentel, Eva

    2013-05-01

    Non-contact Tonopachy NT-530P (Nidek Co., LTD) provides intraocular pressure (IOP) and central corneal thickness (CCT) measurements. This study assesses the reliability and repeatability of its IOP measurements in young healthy adult subjects. IOP was determined in the right eye of 64 healthy patients using Tonopachy followed by the Canon TX-10 non-contact and Goldmann applanation (GAT) tonometers. Tonopachy IOP measurements were corrected (Tonopachy-C) or not (Tonopachy-NC) by the instrument for central corneal thickness. Central corneal thickness measurements provided by Tonopachy were also used to correlate (Pearson's coefficient) central corneal thickness with the GAT and Canon TX-10 IOPs. Repeatability of Tonopachy and GAT was assessed in the right eye of 31 subjects in two separate sessions one week apart. Differences between pairs of instruments and between sessions were determined using Bland-Altman plots. The coefficient of repeatability was calculated as the 95% limits of agreement (LoA) of differences between the two sessions. Tonopachy-NC, Tonopachy-C, Canon TX-10 and the Goldmann tonometers showed a mean IOP of 14.62, 15.64, 15.02 and 14.68 mmHg, respectively. Tonopachy-NC and Canon TX-10 readings did not differ significantly from the Goldmann (p > 0.05), with close agreement with both tonometers (GAT versus Tonopachy-NC: -3.84 to 3.96 mmHg; Goldmann versus Canon TX-10: -4.75 to 4.07 mmHg). Tonopachy-C readings differed significantly from Goldmann (mean difference -0.96 mmHg, p = 0.001, LoA from -5.09 to 3.17). Coefficients of repeatability were ± 3.70, ± 3.14 and ± 3.33 mmHg for GAT, Tonopachy-NC and Tonopachy-C, respectively. Central corneal thickness measured with Tonopachy was 530.42 ± 34.96 μm. There was a significant correlation between central corneal thickness and IOP for all tonometers except Tonopachy-C. Reasonable agreement was observed between the Goldmann and Tonopachy. This instrument provides reliable and repeatable IOP

  16. Selective Non-contact Field Radiofrequency Extended Treatment Protocol: Evaluation of Safety and Efficacy.

    Science.gov (United States)

    Moradi, Amir; Palm, Melanie

    2015-09-01

    Currently there are many non-invasive radiofrequency (RF) devices on the market that are utilized in the field of aesthetic medicine. At this time, there is only one FDA cleared device on the market that emits RF energy using a non-contact delivery system for circumferential reduction by means of adipocyte disruption. Innovation of treatment protocols is an integral part of aesthetic device development. However, when protocol modifications are made it is important to look at the safety as well as the potential for improved efficacy before initiating change. The purpose of this study was to evaluate the safety and efficacy of a newly designed extended treatment protocol using an operator independent selective non-contact RF device for the improvement in the contour and circumferential reduction of the abdomen and flanks (love handles). Twenty-five subjects enrolled in the IRB approved multi-center study to receive four weekly 45-minute RF treatments to the abdomen and love handles. Standardized digital photographs and circumference measurements were taken at baseline and at the 1- and 3-month follow-up visits. Biometric measurements including weight, hydration and body fat were obtained at baseline and each study visit. A subset of 4 subjects were randomly selected to undergo baseline serum lipid and liver-related blood tests with follow-up labs taken: 1 day post-treatment 1, 1 day post-treatment 4, and at the 1- and 3-month follow-up visits. Twenty-four subjects (22 female, 2 male), average age of 47.9 years (30-69 years), completed the study. The data of the twenty-four subjects revealed a statistically significant change in circumference P<.001 with an average decrease in circumference of 4.22cm at the 3-month follow-up visit. Lab values for the subset of 4 subjects remained relatively unchanged with only minor fluctuations noted in the serum lipid values in two of the subjects. Three independent evaluators viewed pre-treatment and 3-month post treatment

  17. Non-Contact Thermal Properties Measurement with Low-Power Laser and IR Camera System

    Science.gov (United States)

    Hudson, Troy L.; Hecht, Michael H.

    2011-01-01

    As shown by the Phoenix Mars Lander's Thermal and Electrical Conductivity Probe (TECP), contact measurements of thermal conductivity and diffusivity (using a modified flux-plate or line-source heat-pulse method) are constrained by a number of factors. Robotic resources must be used to place the probe, making them unavailable for other operations for the duration of the measurement. The range of placement is also limited by mobility, particularly in the case of a lander. Placement is also subject to irregularities in contact quality, resulting in non-repeatable heat transfer to the material under test. Most important from a scientific perspective, the varieties of materials which can be measured are limited to unconsolidated or weakly-cohesive regolith materials, rocks, and ices being too hard for nominal insertion strengths. Accurately measuring thermal properties in the laboratory requires significant experimental finesse, involving sample preparation, controlled and repeatable procedures, and, practically, instrumentation much more voluminous than the sample being tested (heater plates, insulation, temperature sensors). Remote measurements (infrared images from orbiting spacecraft) can reveal composite properties like thermal inertia, but suffer both from a large footprint (low spatial resolution) and convolution of the thermal properties of a potentially layered medium. In situ measurement techniques (the Phoenix TECP is the only robotic measurement of thermal properties to date) suffer from problems of placement range, placement quality, occupation of robotic resources, and the ability to only measure materials of low mechanical strength. A spacecraft needs the ability to perform a non-contact thermal properties measurement in situ. Essential components include low power consumption, leveraging of existing or highly-developed flight technologies, and mechanical simplicity. This new in situ method, by virtue of its being non-contact, bypasses all of these

  18. Tracking Control of an Ultrasonic Linear Motor Actuated Stage Using a Sliding-mode Controller with Friction Compensation

    Directory of Open Access Journals (Sweden)

    Chih-Jer Lin

    2015-02-01

    Full Text Available The purpose of this paper is to investigate the nonlinear friction and compensation for a piezoelectric ceramic ultrasonic motor (USM. Although the architecture of the USM is different from the general electric-mechanical motor, the mathematic model for the USM motor can use the same friction model to formulate the friction phenomenon. To establish the feed-forward controller, the system identification for the USM is needed to study to design the model-based controller. To obtain the optimal system parameters of the USM, PSO and CSS algorithms are studied to identify the system parameters for the nonlinear friction model. For the controller design, a non-model based controller, using back-propagation neural network controller to perform tracking tasks, and the model-based controller, which consists of the feed-forward controller based on the system identification and the sliding-mode control, are discussed in this paper. Finally, the two real-time tracking tasks are used to validate the proposed method.

  19. Non-Contact Surface Roughness Measurement by Implementation of a Spatial Light Modulator.

    Science.gov (United States)

    Aulbach, Laura; Salazar Bloise, Félix; Lu, Min; Koch, Alexander W

    2017-03-15

    The surface structure, especially the roughness, has a significant influence on numerous parameters, such as friction and wear, and therefore estimates the quality of technical systems. In the last decades, a broad variety of surface roughness measurement methods were developed. A destructive measurement procedure or the lack of feasibility of online monitoring are the crucial drawbacks of most of these methods. This article proposes a new non-contact method for measuring the surface roughness that is straightforward to implement and easy to extend to online monitoring processes. The key element is a liquid-crystal-based spatial light modulator, integrated in an interferometric setup. By varying the imprinted phase of the modulator, a correlation between the imprinted phase and the fringe visibility of an interferogram is measured, and the surface roughness can be derived. This paper presents the theoretical approach of the method and first simulation and experimental results for a set of surface roughnesses. The experimental results are compared with values obtained by an atomic force microscope and a stylus profiler.

  20. Novel non-contact control system of electric bed for medical healthcare.

    Science.gov (United States)

    Lo, Chi-Chun; Tsai, Shang-Ho; Lin, Bor-Shyh

    2017-03-01

    A novel non-contact controller of the electric bed for medical healthcare was proposed in this study. Nowadays, the electric beds are widely used for hospitals and home-care, and the conventional control method of the electric beds usually involves in the manual operation. However, it is more difficult for the disabled and bedridden patients, who might totally depend on others, to operate the conventional electric beds by themselves. Different from the current controlling method, the proposed system provides a new concept of controlling the electric bed via visual stimuli, without manual operation. The disabled patients could operate the electric bed by focusing on the control icons of a visual stimulus tablet in the proposed system. Besides, a wearable and wireless EEG acquisition module was also implemented to monitor the EEG signals of patients. The experimental results showed that the proposed system successfully measured and extracted the EEG features related to visual stimuli, and the disabled patients could operate the adjustable function of the electric bed by themselves to effectively reduce the long-term care burden.

  1. Non-contact assessment of melanin distribution via multispectral temporal illumination coding

    Science.gov (United States)

    Amelard, Robert; Scharfenberger, Christian; Wong, Alexander; Clausi, David A.

    2015-03-01

    Melanin is a pigment that is highly absorptive in the UV and visible electromagnetic spectra. It is responsible for perceived skin tone, and protects against harmful UV effects. Abnormal melanin distribution is often an indicator for melanoma. We propose a novel approach for non-contact melanin distribution via multispectral temporal illumination coding to estimate the two-dimensional melanin distribution based on its absorptive characteristics. In the proposed system, a novel multispectral, cross-polarized, temporally-coded illumination sequence is synchronized with a camera to measure reflectance under both multispectral and ambient illumination. This allows us to eliminate the ambient illumination contribution from the acquired reflectance measurements, and also to determine the melanin distribution in an observed region based on the spectral properties of melanin using the Beer-Lambert law. Using this information, melanin distribution maps can be generated for objective, quantitative assessment of skin type of individuals. We show that the melanin distribution map correctly identifies areas with high melanin densities (e.g., nevi).

  2. Non-contact measurement of facial surface vibration patterns during singing by scanning laser Doppler vibrometer

    Directory of Open Access Journals (Sweden)

    Tatsuya eKitamura

    2015-11-01

    Full Text Available This paper presents a method of measuring the vibration patterns onfacial surfaces by using a scanning laser Doppler vibrometer(LDV. The surfaces of the face, neck, and body vibrate duringphonation and, according to Titze (2001, these vibrations occur whenaerodynamic energy is efficiently converted into acoustic energy atthe glottis. A vocalist's vibration velocity patterns may thereforeindicate his or her phonatory status or singing skills. LDVs enablelaser-based non-contact measurement of the vibration velocity anddisplacement of a certain point on a vibrating object, and scanningLDVs permit multipoint measurements. The benefits of scanning LDVsoriginate from the facts that they do not affect the vibrations ofmeasured objects and that they can rapidly measure the vibrationpatterns across planes. A case study is presented herein todemonstrate the method of measuring vibration velocity patterns with ascanning LDV. The objective of the experiment was to measure thevibration velocity differences between the modal and falsettoregisters while three professional soprano singers sang sustainedvowels at four pitch frequencies. The results suggest that there is apossibility that pitch frequency are correlated with vibrationvelocity. However, further investigations are necessary to clarify therelationships between vibration velocity patterns and phonation statusand singing skills.

  3. Non-contact measurement of facial surface vibration patterns during singing by scanning laser Doppler vibrometer.

    Science.gov (United States)

    Kitamura, Tatsuya; Ohtani, Keisuke

    2015-01-01

    This paper presents a method of measuring the vibration patterns on facial surfaces by using a scanning laser Doppler vibrometer (LDV). The surfaces of the face, neck, and body vibrate during phonation and, according to Titze (2001), these vibrations occur when aerodynamic energy is efficiently converted into acoustic energy at the glottis. A vocalist's vibration velocity patterns may therefore indicate his or her phonatory status or singing skills. LDVs enable laser-based non-contact measurement of the vibration velocity and displacement of a certain point on a vibrating object, and scanning LDVs permit multipoint measurements. The benefits of scanning LDVs originate from the facts that they do not affect the vibrations of measured objects and that they can rapidly measure the vibration patterns across planes. A case study is presented herein to demonstrate the method of measuring vibration velocity patterns with a scanning LDV. The objective of the experiment was to measure the vibration velocity differences between the modal and falsetto registers while three professional soprano singers sang sustained vowels at four pitch frequencies. The results suggest that there is a possibility that pitch frequency are correlated with vibration velocity. However, further investigations are necessary to clarify the relationships between vibration velocity patterns and phonation status and singing skills.

  4. A non-contact high resolution piezoelectric film based sensor for monitoring breathing during sleep

    Science.gov (United States)

    Johnston, Robert; Nakano, Katsuya; Fujita, Kento; Misaki, Shinya; Fujii, Hiroyuki; Misaki, Yukinori

    2017-07-01

    Currently, research for measuring human breathing during sleep is actively being conducted into using technologies that include piezoelectric, ultrasonic, microwave and infrared rays. But various problems have led to not many practical applications. As such, it was decided to develop a PVDF (PolyVinylidene DiFluoride) based non-contact high resolution sensor for monitoring a subject's breathing as they sleep. Development of the high resolution respiration sensor was possible through the use of PVDF piezoelectric film and the development of a new sensor configuration. Although there was already an existing respiration sensor research resulting product available, is weak signal strength made it very sensitive to noise and difficult to measure respiration accurately. As such, complicated circuits and signal processing were needed. A new high resolution breathing sensor was developed with greater signal strength and with just the use of some simple circuits and signal processing, was able to accurately measure subject breathing. Also due to the greater signal strength, it became possible to measure both heart rate and respiration rate simultaneously.

  5. Motion Tracking System for Robust Non-Contact Blood Perfusion Sensor

    Directory of Open Access Journals (Sweden)

    Masaaki Hashimoto

    2018-01-01

    Full Text Available We propose a motion-robust laser Doppler flowmetry (LDF system that can be used as a non-contact blood perfusion sensor for medical diagnosis. Endoscopic LDF systems are typically limited in their usefulness in clinical contexts by the need for the natural organs to be immobilized, as serious motion artifacts due to the axial surface displacement can interfere with blood perfusion measurements. In our system, the focusing lens moves to track the motion of the target using a low-frequency reference signal in the optical data, enabling the suppression of these motion artifacts in the axial direction. This paper reports feasibility tests on a prototype of this system using a microfluidic phantom as a measurement target moving in the direction of the optical axis. The frequency spectra detected and the perfusion values calculated from those spectra show that the motion tracking system is capable of suppressing motion artifacts in perfusion readings. We compared the prototype LDF system’s measurements with and without motion feedback, and found that motion tracking improves the fidelity of the perfusion signal by as much as 87%.

  6. Investigation of human body potential measured by a non-contact measuring system

    Science.gov (United States)

    ICHIKAWA, Norimitsu

    2016-01-01

    A human body is occasionally electrified in a room. This charged object will be a source of electrostatic accidents, including the malfunction of electronic equipment. Hence, prevention of these accidents is required. Accidents occasionally occur, even though antistatic clothes and shoes are used. One of the causes for these accidents is that there is a lack of the preventive measures. This situation occurs when using, for example, unconductive wax. In this study, human body potential (voltage) is measured using a non-contact measuring system. An investigation of the human body’s voltage when using this system is conducted. The result demonstrates that the voltage of a human body wearing antistatic clothes and shoes or light clothes and slippers exceeds a malfunctioning voltage of a microelectronics device when the body walks on floors. Thus, accidents may occur even if a human body wearing the antistatic clothes walks on flooring. These results will be useful in estimating determination whether electrostatic accidents occur or not. PMID:27319403

  7. Automatic detection of measurement points for non-contact vibrometer-based diagnosis of cardiac arrhythmias

    Science.gov (United States)

    Metzler, Jürgen; Kroschel, Kristian; Willersinn, Dieter

    2017-03-01

    Monitoring of the heart rhythm is the cornerstone of the diagnosis of cardiac arrhythmias. It is done by means of electrocardiography which relies on electrodes attached to the skin of the patient. We present a new system approach based on the so-called vibrocardiogram that allows an automatic non-contact registration of the heart rhythm. Because of the contactless principle, the technique offers potential application advantages in medical fields like emergency medicine (burn patient) or premature baby care where adhesive electrodes are not easily applicable. A laser-based, mobile, contactless vibrometer for on-site diagnostics that works with the principle of laser Doppler vibrometry allows the acquisition of vital functions in form of a vibrocardiogram. Preliminary clinical studies at the Klinikum Karlsruhe have shown that the region around the carotid artery and the chest region are appropriate therefore. However, the challenge is to find a suitable measurement point in these parts of the body that differs from person to person due to e. g. physiological properties of the skin. Therefore, we propose a new Microsoft Kinect-based approach. When a suitable measurement area on the appropriate parts of the body are detected by processing the Kinect data, the vibrometer is automatically aligned on an initial location within this area. Then, vibrocardiograms on different locations within this area are successively acquired until a sufficient measuring quality is achieved. This optimal location is found by exploiting the autocorrelation function.

  8. Air microjet system for non-contact force application and the actuation of micro-structures

    International Nuclear Information System (INIS)

    Khare, S M; Venkataraman, V

    2016-01-01

    We demonstrate a non-contact technique to apply calibrated and localized forces in the micro-Newton to milli-Newton range using an air microjet. An electromagnetically actuated diaphragm controlled by a signal generator is used to generate the air microjet. With a nozzle diameter of 150 μm, the microjet diameter was maintained to a maximum of 1 mm at a distance of 5 mm from the nozzle. The force generated by the microjet was measured using a commercial force sensor to determine the velocity profile of the jet. Axial flow velocities of up to 25 m s −1 were obtained at distances as long as 6 mm. The microjet exerted a force up to 1 μN on a poly dimethyl siloxane (PDMS) micropillar (50 μm in diameter, 157 μm in height) and 415 μN on a PDMS membrane (3 mm in diameter, 28 μm thick). We also demonstrate that from a distance of 6 mm our microjet can exert a peak pressure of 187 Pa with a total force of about 84 μN on a flat surface with 8 V operating voltage. Out of the cleanroom fabrication and robust design make this system cost effective and durable. (technical note)

  9. The importance of illumination in a non-contact photoplethysmography imaging system for burn wound assessment

    Science.gov (United States)

    Mo, Weirong; Mohan, Rachit; Li, Weizhi; Zhang, Xu; Sellke, Eric W.; Fan, Wensheng; DiMaio, J. Michael; Thatcher, Jeffery E.

    2015-02-01

    We present a non-contact, reflective photoplethysmogram (PPG) imaging method and a prototype system for identifying the presence of dermal burn wounds during a burn debridement surgery. This system aims to provide assistance to clinicians and surgeons in the process of dermal wound management and wound triage decisions. We examined the system variables of illumination uniformity and intensity and present our findings. An LED array, a tungsten light source, and eventually high-power LED emitters were studied as illumination methods for our PPG imaging device. These three different illumination sources were tested in a controlled tissue phantom model and an animal burn model. We found that the low heat and even illumination pattern using high power LED emitters provided a substantial improvement to the collected PPG signal in our animal burn model. These improvements allow the PPG signal from different pixels to be comparable in both time-domain and frequency-domain, simplify the illumination subsystem complexity, and remove the necessity of using high dynamic range cameras. Through the burn model output comparison, such as the blood volume in animal burn data and controlled tissue phantom model, our optical improvements have led to more clinically applicable images to aid in burn assessment.

  10. Modelling atomic scale manipulation with the non-contact atomic force microscope

    International Nuclear Information System (INIS)

    Trevethan, T; Watkins, M; Kantorovich, L N; Shluger, A L; Polesel-Maris, J; Gauthier, S

    2006-01-01

    We present the results of calculations performed to model the process of lateral manipulation of an oxygen vacancy in the MgO(001) surface using the non-contact atomic force microscope (NC-AFM). The potential energy surfaces for the manipulation as a function of tip position are determined from atomistic modelling of the MgO(001) surface interacting with a Mg terminated MgO tip. These energies are then used to model the dynamical evolution of the system as the tip oscillates and at a finite temperature using a kinetic Monte Carlo method. The manipulation process is strongly dependent on the lateral position of the tip and the system temperature. It is also found that the expectation value of the point at which the vacancy jumps depends on the trajectory of the oscillating cantilever as the surface is approached. The effect of the manipulation on the operation of the NC-AFM is modelled with a virtual dynamic AFM, which explicitly simulates the entire experimental instrumentation and control loops. We show how measurable experimental signals can result from a single controlled atomic scale event and suggest the most favourable conditions for achieving successful atomic scale manipulation experimentally

  11. Torque Ripple Reduction of a Novel Modular Arc-Linear Flux-Switching Permanent-Magnet Motor with Rotor Step Skewing

    Directory of Open Access Journals (Sweden)

    Xiangdong Liu

    2016-05-01

    Full Text Available A novel modular arc-linear flux-switching permanent-magnet motor (MAL-FSPM used for scanning system instead of reduction gearboxes and kinematic mechanisms is proposed and researched in this paper by the finite element method (FEM. The MAL-FSPM combines characteristics of flux-switching permanent-magnet motor and linear motor and can realize the direct driving and limited angular movement. Structure and operation principle of the MAL-FSPM are analyzed. Cogging torque model of the MAL-FSPM is established. The characteristics of cogging torque and torque ripple are investigated for: (1 distance (dend between left end of rotor and left end of stator is more than two rotor tooth pitch (τp; and (2 dend is less than two rotor tooth pitch. Cogging torque is an important component of torque ripple and the period ratio of the cogging torque to the back electromotive force (EMF equals one for the MAL-FSPM before optimization. In order to reduce the torque ripple as much as possible and affect the back EMF as little as possible, influence of period ratio of cogging torque to back EMF on rotor step skewing is investigated. Rotor tooth width and stator slot open width are optimized to increase the period ratio of cogging torque to back EMF. After the optimization, torque ripple is decreased by 79.8% for dend > τp and torque ripple is decreased by 49.7% for dend < τp. Finally, 3D FEM model is established to verify the 2D results.

  12. Endoluminal non-contact soft tissue ablation using fiber-based Er:YAG laser delivery

    Science.gov (United States)

    Kundrat, Dennis; Fuchs, Alexander; Schoob, Andreas; Kahrs, Lüder A.; Ortmaier, Tobias

    2016-03-01

    The introduction of Er:YAG lasers for soft and hard tissue ablation has proven promising results over the last decades due to strong absorption at 2.94 μm wavelength by water molecules. An extension to endoluminal applications demands laser delivery without mirror arms due to dimensional constraints. Therefore, fiber-based solutions are advanced to provide exible access while keeping space requirements to a minimum. Conventional fiber-based treatments aim at laser-tissue interactions in contact mode. However, this procedure is associated with disadvantages such as advancing decrease in power delivery due to particle coverage of the fiber tip, tissue carbonization, and obstructed observation of the ablation progress. The objective of this work is to overcome aforementioned limitations with a customized fiber-based module for non-contact robot-assisted endoluminal surgery and its associated experimental evaluation. Up to the authors knowledge, this approach has not been presented in the context of laser surgery at 2.94 μm wavelength. The preliminary system design is composed of a 3D Er:YAG laser processing unit enabling automatic laser to fiber coupling, a GeO2 solid core fiber, and a customized module combining collimation and focusing unit (focal length of 20 mm, outer diameter of 8 mm). The performance is evaluated with studies on tissue substitutes (agar-agar) as well as porcine samples that are analysed by optical coherence tomography measurements. Cuts (depths up to 3mm) with minimal carbonization have been achieved under adequate moistening and sample movement (1.5mms-1). Furthermore, an early cadaver study is presented. Future work aims at module miniaturization and integration into an endoluminal robot for scanning and focus adaptation.

  13. RELIABILITY OF A CONTACT AND NON-CONTACT SIMULATED TEAM GAME CIRCUIT

    Directory of Open Access Journals (Sweden)

    Tarveen K.R. Singh

    2010-12-01

    Full Text Available Most team sports are characterised by repeated short maximal sprint efforts interspersed with longer periods of active recovery or rest. Although a variety of testing protocols have been devised to simulate these activity patterns under controlled conditions, a common limitation is the lack of 'body contact' to simulate the tackling efforts seen in contact sports. Therefore, the purpose of this study was to assess the reliability of a simulated team game protocol with and without 'contact'. Eleven male, team-sport athletes (mean ± SD; age 22 ± 2 yr; BMI 23.0 ± 1.7 kg·m-2 completed four separate testing trials; two 'non-contact' trials (NCON and two 'contact' (CON trials of a simulated game to determine the reliability of a range of team sport performance indicators including repeated 15-m sprint time, vertical jump height, heart rate response and ratings of perceived exertion (RPE. The team game protocol involved four sets of 15-min of intermittent running around a circuit replicating the movement patterns observed in team sports, either with or without simulated contact. Within-subject reliability of each performance measure was determined by expressing the typical error of measurement as the coefficient of variation, as well as determining intra-class correlations. Both CON and NCON produced reliable results for a variety of team sport performance indicators including repeated 15-m sprint time, vertical jump height, heart rate response and RPE. Repeated sprint and jump performance declined over time throughout the simulated game (p < 0.05, while heart rate and RPE increased. There was no difference in these performance measures between CON and NCON protocols. As such, these simulated game protocols provide reliable options for assessing team game performance parameters in response to training or other interventions under controlled conditions

  14. Measurements of anterior segment parameters using three different non-contact optical devices in keratoconus patients

    Directory of Open Access Journals (Sweden)

    Ahmet Taylan Yazıcı

    2013-08-01

    Full Text Available AIM: To evaluate the measurements of anterior segment parameters using three different non-contact optical devices in keratoconus patients.METHODS:A hundred and one eyes of 55 keratoconus patients were enrolled in this study. The mean age was 26.2±8.9 years. The inclusion criteria were keratoconus stage I to III according to the Amsler-Krumeich keratoconus classification. All the measurements were done by the same operator, under the mesopic light condition and repeated with three different optical methods; Visante , Orbscan and Pentacam. The evaluated anterior segment parameters were anterior chamber depth (ACD, central and thinnest corneal thickness (CCT and TCT and pupil diameter (PD.RESULTS: The mean CCT measured by Visante, Orbscan and Pentacam were as follows:462.0±48.1µm, 463.9±60.9µm, 476.5±45.3µm, respectively (P=0.873. The mean ACD values were 3.34±0.33mm, 3.26±0.33mm, 3.49±0.40mm, respectively (P=0.118. The mean PD measurements were 5.11±1.14mm, 4.80±0.85mm, 3.80±1.38mm, respectively (PP=0.214. The Visante and Orbscan measured CCT similarly, while Pentacam measured CCT thicker than the other two. The Visante measured TCT thinner than the other two devices. In ACD measurements, Orbscan was the one giving the lowest values. PD was measured differently by the devices.CONCLUSION: Although TCT, CCT and ACD measurements acquired by Visante, Orbscan and Pentacam in keratoconus patients are similar, PD measurements show large differences among the devices.

  15. Quantitative assessment of contact and non-contact lateral force calibration methods for atomic force microscopy

    International Nuclear Information System (INIS)

    Tran Khac, Bien Cuong; Chung, Koo-Hyun

    2016-01-01

    Atomic Force Microscopy (AFM) has been widely used for measuring friction force at the nano-scale. However, one of the key challenges faced by AFM researchers is to calibrate an AFM system to interpret a lateral force signal as a quantifiable force. In this study, five rectangular cantilevers were used to quantitatively compare three different lateral force calibration methods to demonstrate the legitimacy and to establish confidence in the quantitative integrity of the proposed methods. The Flat-Wedge method is based on a variation of the lateral output on a surface with flat and changing slopes, the Multi-Load Pivot method is based on taking pivot measurements at several locations along the cantilever length, and the Lateral AFM Thermal-Sader method is based on determining the optical lever sensitivity from the thermal noise spectrum of the first torsional mode with a known torsional spring constant from the Sader method. The results of the calibration using the Flat-Wedge and Multi-Load Pivot methods were found to be consistent within experimental uncertainties, and the experimental uncertainties of the two methods were found to be less than 15%. However, the lateral force sensitivity determined by the Lateral AFM Thermal-Sader method was found to be 8–29% smaller than those obtained from the other two methods. This discrepancy decreased to 3–19% when the torsional mode correction factor for an ideal cantilever was used, which suggests that the torsional mode correction should be taken into account to establish confidence in Lateral AFM Thermal-Sader method. - Highlights: • Quantitative assessment of three lateral force calibration methods for AFM. • Advantages and disadvantages of three different lateral force calibration method. • Implementation of Multi-Load Pivot method as non-contact calibration technique. • The torsional mode correction for Lateral AFM Thermal-Sader method.

  16. Evaluation techniques of accuracy characteristics for non-contact photonic track inspection system

    Science.gov (United States)

    Popov, Dmitry V.; Ryabichenko, Roman B.; Krivosheina, Elena A.

    2005-06-01

    The most important task in Moscow metro is increasing safety of railway traffic. For safety purposes six track parameters are measured in Moscow Metro with help of track measurement car. Equipment mounted on this car works only in contact mode and doesn't provide modem requirements for accuracy. Also important task is measurement at high speeds, but contact technology limits speed of movement up to 25mph on rail switches. Current system can't measure in real-time mode. For decision of these field of tasks non-contact photonic measurement system (KSIR) is constructed. The KSIR works at speeds up to 70 mph and measure seven track parameters. The KSIR contains four subsystems: rail wear, height and track gauge measurement (BFSM); rail slump measurement (FTP); contact rail measurement (FKR); speed, level and car locating (USI). KSIR contains five CCD matrix cameras, four line CCD cameras, five infrared stripe lasers and four spot infrared lasers. Laser forms shape on the rail. CCD-camera acquires rail image and transfers it into the digital signal processor which produces preliminary calculation ofrail shape. Then image is transferred into the central computer to calculate values of rail characteristics. Angles between photonic unit and rail bring distortions in images from cameras. Additional distortions are caused by short-focus optics and small distance between camera and track. This distance is limited by structure clearance. The transformation algorithms for distortions elimination are applied. It's based on surfaces spline-approximation. As a result the KSIR calculates coefficients of approximating polynomials. The calibration is performed for checking accuracy of measurement in BFSM, FTP and FKR units. Evaluation techniques of accuracy characteristics are considered.

  17. Sleep stage classification by non-contact vital signs indices using Doppler radar sensors.

    Science.gov (United States)

    Kagawa, Masayuki; Suzumura, Kazuki; Matsui, Takemi

    2016-08-01

    Disturbed sleep has become more common in recent years. To improve the quality of sleep, undergoing sleep observation has gained interest as a means to resolve possible problems. In this paper, we evaluate a non-restrictive and non-contact method for classifying real-time sleep stages and report on its potential applications. The proposed system measures heart rate (HR), heart rate variability (HRV), body movements, and respiratory signals of a sleeping person using two 24-GHz microwave radars placed beneath the mattress. We introduce a method that dynamically selects the window width of the moving average filter to extract the pulse waves from the radar output signals. The Pearson correlation coefficient between two HR measurements derived from the radars overnight, and the reference polysomnography was the average of 88.3% and the correlation coefficient for HRV parameters was the average of 71.2%. For identifying wake and sleep periods, the body-movement index reached sensitivity of 76.0%, and a specificity of 77.0% with 10 participants. Low-frequency (LF) components of HRV and the LF/HF ratio had a high degree of contribution and differed significantly across the three sleep stages (REM, LIGHT, and DEEP; p 0.05). We applied a canonical discriminant analysis to identify wake or sleep periods and to classify the three sleep stages with leave-one-out cross validation. Classification accuracy was 66.4% for simply identifying wake and sleep, 57.1% for three stages (wake, REM, and NREM) and 34% for four stages (wake, REM, LIGHT, and DEEP). This is a novel system for measuring HRs, HRV, body movements, and respiratory intervals and for measuring high sensitivity pulse waves using two radar signals. It simplifies measurement of sleep stages and may be employed at nursing care facilities or by the general public to improve sleep quality.

  18. Comparison of corneal endothelial cell measurements by two non-contact specular microscopes.

    Science.gov (United States)

    Gasser, Laura; Reinhard, Thomas; Böhringer, Daniel

    2015-07-29

    Measurement of corneal endothelial cell density is important both for clinical diagnosis as well as clinical studies. Since endothelial cell loss is considered irreversible in humans, even small changes in endothelial cell density are relevant. Therefore it is important to know whether different instruments for endothelial cell density measurements give the same results and can thus be used interchangeably. In this study we compare corneal endothelial cell density and morphometry measurements from two widely used non-contact specular microscopes, the Topcon SP3000P and Konan Noncon Robo SP8000. Endothelial cell measurements were performed with both the Topcon SP3000P and Konan Noncon Robo SP8000 on 34 eyes of 18 consecutive patients of our cornea clinics with poor image quality being the only exclusion criterion. Images were obtained using the auto-focussing method and manual cell selection. Endothelial cell density (ECD), hexagonal cell ratio (HEX) and coefficient of value (CV) of the endothelial cell layer were calculated by the instruments' built-in software. ECD values calculated by the Konan were systematically higher than Topcon values: in 94 % of eyes Konan gave a higher value than Topcon, leading to a mean difference in ECD between the instruments of 187 cells/mm(2) (P < 0.001 in paired Wilcoxon test). HEX showed a broad range of values and differed greatly with only weak correlation between the two instruments. CV values for Konan mostly exceeded Topcon values, and only showed a weak correlation between the two instruments as well. Values for ECD between the Konan and the Topcon do correlate well, but the ECDs calculated by the Konan are systematically higher than Topcon values. Both HEX and CV vary greatly and do not correlate sufficiently. Thus we recommend not to use the Konan and the Topcon instrument interchangeably.

  19. Quantitative assessment of contact and non-contact lateral force calibration methods for atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tran Khac, Bien Cuong; Chung, Koo-Hyun, E-mail: khchung@ulsan.ac.kr

    2016-02-15

    Atomic Force Microscopy (AFM) has been widely used for measuring friction force at the nano-scale. However, one of the key challenges faced by AFM researchers is to calibrate an AFM system to interpret a lateral force signal as a quantifiable force. In this study, five rectangular cantilevers were used to quantitatively compare three different lateral force calibration methods to demonstrate the legitimacy and to establish confidence in the quantitative integrity of the proposed methods. The Flat-Wedge method is based on a variation of the lateral output on a surface with flat and changing slopes, the Multi-Load Pivot method is based on taking pivot measurements at several locations along the cantilever length, and the Lateral AFM Thermal-Sader method is based on determining the optical lever sensitivity from the thermal noise spectrum of the first torsional mode with a known torsional spring constant from the Sader method. The results of the calibration using the Flat-Wedge and Multi-Load Pivot methods were found to be consistent within experimental uncertainties, and the experimental uncertainties of the two methods were found to be less than 15%. However, the lateral force sensitivity determined by the Lateral AFM Thermal-Sader method was found to be 8–29% smaller than those obtained from the other two methods. This discrepancy decreased to 3–19% when the torsional mode correction factor for an ideal cantilever was used, which suggests that the torsional mode correction should be taken into account to establish confidence in Lateral AFM Thermal-Sader method. - Highlights: • Quantitative assessment of three lateral force calibration methods for AFM. • Advantages and disadvantages of three different lateral force calibration method. • Implementation of Multi-Load Pivot method as non-contact calibration technique. • The torsional mode correction for Lateral AFM Thermal-Sader method.

  20. Automatic Detection of Whole Night Snoring Events Using Non-Contact Microphone

    Science.gov (United States)

    Dafna, Eliran; Tarasiuk, Ariel; Zigel, Yaniv

    2013-01-01

    Objective Although awareness of sleep disorders is increasing, limited information is available on whole night detection of snoring. Our study aimed to develop and validate a robust, high performance, and sensitive whole-night snore detector based on non-contact technology. Design Sounds during polysomnography (PSG) were recorded using a directional condenser microphone placed 1 m above the bed. An AdaBoost classifier was trained and validated on manually labeled snoring and non-snoring acoustic events. Patients Sixty-seven subjects (age 52.5±13.5 years, BMI 30.8±4.7 kg/m2, m/f 40/27) referred for PSG for obstructive sleep apnea diagnoses were prospectively and consecutively recruited. Twenty-five subjects were used for the design study; the validation study was blindly performed on the remaining forty-two subjects. Measurements and Results To train the proposed sound detector, >76,600 acoustic episodes collected in the design study were manually classified by three scorers into snore and non-snore episodes (e.g., bedding noise, coughing, environmental). A feature selection process was applied to select the most discriminative features extracted from time and spectral domains. The average snore/non-snore detection rate (accuracy) for the design group was 98.4% based on a ten-fold cross-validation technique. When tested on the validation group, the average detection rate was 98.2% with sensitivity of 98.0% (snore as a snore) and specificity of 98.3% (noise as noise). Conclusions Audio-based features extracted from time and spectral domains can accurately discriminate between snore and non-snore acoustic events. This audio analysis approach enables detection and analysis of snoring sounds from a full night in order to produce quantified measures for objective follow-up of patients. PMID:24391903

  1. Automatic detection of whole night snoring events using non-contact microphone.

    Directory of Open Access Journals (Sweden)

    Eliran Dafna

    Full Text Available OBJECTIVE: Although awareness of sleep disorders is increasing, limited information is available on whole night detection of snoring. Our study aimed to develop and validate a robust, high performance, and sensitive whole-night snore detector based on non-contact technology. DESIGN: Sounds during polysomnography (PSG were recorded using a directional condenser microphone placed 1 m above the bed. An AdaBoost classifier was trained and validated on manually labeled snoring and non-snoring acoustic events. PATIENTS: Sixty-seven subjects (age 52.5 ± 13.5 years, BMI 30.8 ± 4.7 kg/m(2, m/f 40/27 referred for PSG for obstructive sleep apnea diagnoses were prospectively and consecutively recruited. Twenty-five subjects were used for the design study; the validation study was blindly performed on the remaining forty-two subjects. MEASUREMENTS AND RESULTS: To train the proposed sound detector, >76,600 acoustic episodes collected in the design study were manually classified by three scorers into snore and non-snore episodes (e.g., bedding noise, coughing, environmental. A feature selection process was applied to select the most discriminative features extracted from time and spectral domains. The average snore/non-snore detection rate (accuracy for the design group was 98.4% based on a ten-fold cross-validation technique. When tested on the validation group, the average detection rate was 98.2% with sensitivity of 98.0% (snore as a snore and specificity of 98.3% (noise as noise. CONCLUSIONS: Audio-based features extracted from time and spectral domains can accurately discriminate between snore and non-snore acoustic events. This audio analysis approach enables detection and analysis of snoring sounds from a full night in order to produce quantified measures for objective follow-up of patients.

  2. Automatic detection of whole night snoring events using non-contact microphone.

    Science.gov (United States)

    Dafna, Eliran; Tarasiuk, Ariel; Zigel, Yaniv

    2013-01-01

    Although awareness of sleep disorders is increasing, limited information is available on whole night detection of snoring. Our study aimed to develop and validate a robust, high performance, and sensitive whole-night snore detector based on non-contact technology. Sounds during polysomnography (PSG) were recorded using a directional condenser microphone placed 1 m above the bed. An AdaBoost classifier was trained and validated on manually labeled snoring and non-snoring acoustic events. Sixty-seven subjects (age 52.5 ± 13.5 years, BMI 30.8 ± 4.7 kg/m(2), m/f 40/27) referred for PSG for obstructive sleep apnea diagnoses were prospectively and consecutively recruited. Twenty-five subjects were used for the design study; the validation study was blindly performed on the remaining forty-two subjects. To train the proposed sound detector, >76,600 acoustic episodes collected in the design study were manually classified by three scorers into snore and non-snore episodes (e.g., bedding noise, coughing, environmental). A feature selection process was applied to select the most discriminative features extracted from time and spectral domains. The average snore/non-snore detection rate (accuracy) for the design group was 98.4% based on a ten-fold cross-validation technique. When tested on the validation group, the average detection rate was 98.2% with sensitivity of 98.0% (snore as a snore) and specificity of 98.3% (noise as noise). Audio-based features extracted from time and spectral domains can accurately discriminate between snore and non-snore acoustic events. This audio analysis approach enables detection and analysis of snoring sounds from a full night in order to produce quantified measures for objective follow-up of patients.

  3. Effects of puff times on intraocular pressure agreement between non-contact and Goldmann applanation tonometers

    Directory of Open Access Journals (Sweden)

    Ibrahim Toprak

    2014-07-01

    Full Text Available AIM: To compare intraocular pressure(IOPvalues obtained from two different puff modes of Canon TX-F non-contact tonometer(NCTand Goldmann applanation tonometer(GATin patients with primary open angle glaucoma(POAG. METHODS: The study group comprised 55 right eyes of 55 patients with a confirmed diagnosis of POAG, which were under treatment. All patients underwent detailed ophthalmological examinations, optical coherence tomography imaging and automated perimetry. Intraocular pressure measurements were performed using 1-puff mode of NCT(NCT1, 3-puffs mode of NCT(NCT3and GAT with 5 minutes intervals in order. RESULTS: Fifty-five eyes of 55 patients with POAG(mean age of 64.1±8.1 yearswere enrolled into the study. NCT1 and NCT3 gave similar IOP values when compared with GAT measurements(14.22±3.42, 14.28±3.29, 14.66±3.49mmHg respectively, P=0.291. Intertonometer agreement was assessed using the Bland-Altman method. The 95% limits of agreement(LoAfor NCT1-GAT, NCT3-GAT and NCT1-NCT3 comparisons were -4.9 to +4.4mmHg, -4.1 to +3.4mmHg, and -3.4 to +3.3mmHg respectively.CONCLUSION: Although IOP measurements obtained from two puff modes of NCT and GAT showed similar values, wide range of LoA might restrict use of NCT1, NCT3 and GAT interchangeably in POAG patients.

  4. Non-contact Real-time heart rate measurements based on high speed circuit technology research

    Science.gov (United States)

    Wu, Jizhe; Liu, Xiaohua; Kong, Lingqin; Shi, Cong; Liu, Ming; Hui, Mei; Dong, Liquan; Zhao, Yuejin

    2015-08-01

    In recent years, morbidity and mortality of the cardiovascular or cerebrovascular disease, which threaten human health greatly, increased year by year. Heart rate is an important index of these diseases. To address this status, the paper puts forward a kind of simple structure, easy operation, suitable for large populations of daily monitoring non-contact heart rate measurement. In the method we use imaging equipment video sensitive areas. The changes of light intensity reflected through the image grayscale average. The light change is caused by changes in blood volume. We video the people face which include the sensitive areas (ROI), and use high-speed processing circuit to save the video as AVI format into memory. After processing the whole video of a period of time, we draw curve of each color channel with frame number as horizontal axis. Then get heart rate from the curve. We use independent component analysis (ICA) to restrain noise of sports interference, realized the accurate extraction of heart rate signal under the motion state. We design an algorithm, based on high-speed processing circuit, for face recognition and tracking to automatically get face region. We do grayscale average processing to the recognized image, get RGB three grayscale curves, and extract a clearer pulse wave curves through independent component analysis, and then we get the heart rate under the motion state. At last, by means of compare our system with Fingertip Pulse Oximeter, result show the system can realize a more accurate measurement, the error is less than 3 pats per minute.

  5. Non-contact hematoma damage and healing assessment using reflectance photoplethysmographic imaging

    Science.gov (United States)

    Amelard, Robert; Pfisterer, Kaylen J.; Clausi, David A.; Wong, Alexander

    2016-03-01

    Impact trauma may cause a hematoma, which is the leakage of venous blood into surrounding tissues. Large hematomas can be dangerous as they may inhibit local blood ow. Hematomas are often diagnosed visually, which may be problematic if the hematoma leaks deeper than the visible penetration depth. Furthermore, vascular wound healing is often monitored at home without the aid of a clinician. We therefore investigated the use of near infrared (NIR) re ectance photoplethysmographic imaging (PPGI) to assess vascular damage resulting from a hematoma, and monitor the healing process. In this case study, the participant experienced internal vascular damage in the form of a hematoma. Using a PPGI system with dual-mode temporally coded illumination for ambient-agnostic data acquisition and mounted optical elements, the tissue was illuminated with a spatially uniform irradiance pattern of 850 nm wavelength light for increased tissue penetration and high oxy-to-deoxyhemoglobin absorption ratio. Initial and follow-up PPGI data collection was performed to assess vascular damage and healing. The tissue PPGI sequences were spectrally analyzed, producing spectral maps of the tissue area. Experimental results show that spatial differences in spectral information can be observed around the damaged area. In particular, the damaged site exhibited lower pulsatility than the surrounding healthy tissue. This pulsatility was largely restored in the follow-up data, suggesting that the tissue had undergone vascular healing. These results indicate that hematomas can be assessed and monitored in a non-contact visual manner, and suggests that PPGI can be used for tissue health assessment, with potential extensions to peripheral vascular disease.

  6. An adaptive Kalman filter approach for cardiorespiratory signal extraction and fusion of non-contacting sensors.

    Science.gov (United States)

    Foussier, Jerome; Teichmann, Daniel; Jia, Jing; Misgeld, Berno; Leonhardt, Steffen

    2014-05-09

    Extracting cardiorespiratory signals from non-invasive and non-contacting sensor arrangements, i.e. magnetic induction sensors, is a challenging task. The respiratory and cardiac signals are mixed on top of a large and time-varying offset and are likely to be disturbed by measurement noise. Basic filtering techniques fail to extract relevant information for monitoring purposes. We present a real-time filtering system based on an adaptive Kalman filter approach that separates signal offsets, respiratory and heart signals from three different sensor channels. It continuously estimates respiration and heart rates, which are fed back into the system model to enhance performance. Sensor and system noise covariance matrices are automatically adapted to the aimed application, thus improving the signal separation capabilities. We apply the filtering to two different subjects with different heart rates and sensor properties and compare the results to the non-adaptive version of the same Kalman filter. Also, the performance, depending on the initialization of the filters, is analyzed using three different configurations ranging from best to worst case. Extracted data are compared with reference heart rates derived from a standard pulse-photoplethysmographic sensor and respiration rates from a flowmeter. In the worst case for one of the subjects the adaptive filter obtains mean errors (standard deviations) of -0.2 min(-1) (0.3 min(-1)) and -0.7 bpm (1.7 bpm) (compared to -0.2 min(-1) (0.4 min(-1)) and 42.0 bpm (6.1 bpm) for the non-adaptive filter) for respiration and heart rate, respectively. In bad conditions the heart rate is only correctly measurable when the Kalman matrices are adapted to the target sensor signals. Also, the reduced mean error between the extracted offset and the raw sensor signal shows that adapting the Kalman filter continuously improves the ability to separate the desired signals from the raw sensor data. The average total computational time needed

  7. Development of a Nondestructive Non-Contact Acousto-Thermal Evaluation Technique for Damage Detection in Materials (Preprint)

    Science.gov (United States)

    2011-11-01

    evaluate incipient thermal damage in composite structures. An aluminum aircraft wheel with a crack was used to show the applicability of the technique...ultrasonic and thermography NDE techniques have been valuable in detecting damage due to sub-surface delamination. Thermal exposure of PMCs can cause...AFRL-RX-WP-TP-2011-4366 DEVELOPMENT OF A NONDESTRUCTIVE NON- CONTACT ACOUSTO-THERMAL EVALUATION TECHNIQUE FOR DAMAGE DETECTION IN MATERIALS

  8. Development of Nondestructive Non-Contact Acousto-Thermal Evaluation Technique for Damage Detection in Materials (Postprint)

    Science.gov (United States)

    2012-09-01

    used to demonstrate the capability of the NCATS technique to evaluate incipient thermal damage in composite structures. An aluminum alloy aircraft wheel...extensive damage that can be detected visually without much difficulty. When the damage is not visible, ultrasonic and thermography NDE techniques have...AFRL-RX-WP-JA-2014-0223 DEVELOPMENT OF NONDESTRUCTIVE NON- CONTACT ACOUSTO-THERMAL EVALUATION TECHNIQUE FOR DAMAGE DETECTION IN MATERIALS

  9. Antennas for Terahertz Applications: Focal Plane Arrays and On-chip Non-contact Measurement Probes

    Science.gov (United States)

    Trichopoulos, Georgios C.

    . Additionally, a butterfly-shaped antenna layout is introduced that enables broadband imaging. The alternative design presented here, allows for video-rate imaging in the 0.6--1.2 THz band and maintains a small antenna footprint, resulting in densely packed FPAs. In both antenna designs, we optimize the impedance matching between the antennas and the integrated electronic devices, thus achieving optimum responsivity levels for high sensitivity and low noise performance. Subsequently, we present the design details of the first THz camera and the first THz camera images captured. With the realized THz camera, imaging of concealed objects is achieved with computer tomography system that allows rapid cross-sectional imaging (˜2 min). For the design and analysis of the THz camera performance, we developed an in-house hybrid electromagnetic model, combining full-wave and high-frequency computational methods. The antenna radiation and impedance computation is first carried out using full-wave modeling of the FPA. Subsequently, we employ scalar diffraction theory to compute the field distribution at any point in space. Thus, the hybrid electromagnetic model allows fast and accurate design of THz antennas and modeling of the complete THz imaging system. Finally, motivated by the novel THz antenna layouts and the quasioptical techniques, we developed a novel non-contact probe measurement method for on-chip device characterization. In the THz regime, traditional contact probes are too small and fragile, thus inhibiting accurate and reliable circuit measurements. By integrating the device under test (DUT) with THz antennas that act as the measurement probes, we may couple the incident and reflected signal from and to the network analyzer without residing to any physical connection.

  10. Development and application of a portable manual non-contact-type goniometric instrument for measuring human anatomical angular parameters.

    Science.gov (United States)

    Susato, Shin-ichi

    2013-02-01

    Several manual contact-type goniometric instruments have previously been developed to measure joint range of motion (ROM) during physical-therapy evaluation. These include the universal goniometer and the gravity-dependent goniometer, or inclinometer, which are used to measure the ROM angle of a subject in a fully erect posture. Here, we developed a manual non-contact-type portable goniometric instrument for the measurement of anatomical angular parameters based on the principle of spot irradiation by using laser markers. The accuracy of the developed instrument was tested and its performance was compared with that of a contact-type instrument by using a skeletal model (14 static angle assessments), a free posture manikin (18 static angle assessments), and healthy human bodies (5 males and 5 females; 11 dynamic angle assessments). Measurement errors were examined also. When taking the measurements, a visual landmark-detection method was used in place of the conventional palpation method, which is inappropriate for a non-contact measuring system. The instrument developed here is applicable for practical non-contact goniometry and ROM measurements. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  11. Design and Parametric Study of the Magnetic Sensor for Position Detection in Linear Motor Based on Nonlinear Parametric model order reduction.

    Science.gov (United States)

    Paul, Sarbajit; Chang, Junghwan

    2017-07-01

    This paper presents a design approach for a magnetic sensor module to detect mover position using the proper orthogonal decomposition-dynamic mode decomposition (POD-DMD)-based nonlinear parametric model order reduction (PMOR). The parameterization of the sensor module is achieved by using the multipolar moment matching method. Several geometric variables of the sensor module are considered while developing the parametric study. The operation of the sensor module is based on the principle of the airgap flux density distribution detection by the Hall Effect IC. Therefore, the design objective is to achieve a peak flux density (PFD) greater than 0.1 T and total harmonic distortion (THD) less than 3%. To fulfill the constraint conditions, the specifications for the sensor module is achieved by using POD-DMD based reduced model. The POD-DMD based reduced model provides a platform to analyze the high number of design models very fast, with less computational burden. Finally, with the final specifications, the experimental prototype is designed and tested. Two different modes, 90° and 120° modes respectively are used to obtain the position information of the linear motor mover. The position information thus obtained are compared with that of the linear scale data, used as a reference signal. The position information obtained using the 120° mode has a standard deviation of 0.10 mm from the reference linear scale signal, whereas the 90° mode position signal shows a deviation of 0.23 mm from the reference. The deviation in the output arises due to the mechanical tolerances introduced into the specification during the manufacturing process. This provides a scope for coupling the reliability based design optimization in the design process as a future extension.

  12. Comparison of Thrust Characteristics in Pencil Sized Cylinder-type Linear Motors with Different Magnet Arrays(Asia-Pacific Symposium on Applied Electromagnetics and Mechanics (APSAEM08))

    OpenAIRE

    K., Nakaiwa; A., Yamada; K., Tashiro; H., Wakiwaka; Tamagawa-Seiki Co., Ltd; Shinshu University; Shinshu University; Shinshu University

    2009-01-01

    From a strong demand on the miniaturization of a chip mounter or a semiconductor device, the thrust improvement considering the magnets arrangement is studied. We accept a core stator with a Halbach type magnet array for a current linear motor. The thrust characteristics are compared with two kinds of mover, a NS magnet array and a Halbach magnet array.

  13. Non-contact lens use-related Acanthamoeba keratitis in southern Turkey: evaluation of risk factors and clinical features.

    Science.gov (United States)

    Erdem, Elif; Evcil, Yusuf; Yagmur, Meltem; Eroglu, Fadime; Koltas, Soner; Ersoz, Reha

    2014-01-01

    To assess the diagnostic methods, risk factors, and clinical features of Acanthamoeba keratitis cases in patients who do not wear contact lenses. Medical records of 26 consecutive patients with non-contact lens-related Acanthamoeba keratitis, who were followed up at the tertiary eye care center between May 2010 and May 2012, were analyzed. Laboratory, demographic, and clinical findings were evaluated pertaining to the patients. Twenty-six non-contact lens-related Acanthamoeba keratitis cases were included in the study. The main risk factors were trauma (group 1, n = 13 patients) and ocular surface disease (group 2, n = 12 patients). One patient had both of the risk factors mentioned above. Overall test results showed that Acanthamoeba positivity rates were 15.3% for direct microscopy, 46.1% for culture, 92.3% for conventional polymerase chain reaction (PCR), and 100% for real-time PCR. The rates of full-thickness corneal involvement and ring-shaped infiltrations were higher in group 2, whereas superficial keratitis and radial keratoneuritis were higher in group 1. The final visual acuities were significantly better in group 1 than group 2 (pAcanthamoeba keratitis in non-contact lens users. A majority of cases admitted to a tertiary eye care center were related to trauma or ocular surface disease. Physician suspicion is critically important for the timely diagnosis of these cases. At this point, molecular diagnostic tests (PCR or real-time PCR) seem to support the clinical diagnosis of Acanthamoeba keratitis with the help of fast and reliable results.

  14. Multi-Objective Optimization of Moving-magnet Linear Oscillatory Motor Using Response Surface Methodology with Quantum-Behaved PSO Operator

    Science.gov (United States)

    Lei, Meizhen; Wang, Liqiang

    2018-01-01

    To reduce the difficulty of manufacturing and increase the magnetic thrust density, a moving-magnet linear oscillatory motor (MMLOM) without inner-stators was Proposed. To get the optimal design of maximum electromagnetic thrust with minimal permanent magnetic material, firstly, the 3D finite element analysis (FEA) model of the MMLOM was built and verified by comparison with prototype experiment result. Then the influence of design parameters of permanent magnet (PM) on the electromagnetic thrust was systematically analyzed by the 3D FEA to get the design parameters. Secondly, response surface methodology (RSM) was employed to build the response surface model of the new MMLOM, which can obtain an analytical model of the PM volume and thrust. Then a multi-objective optimization methods for design parameters of PM, using response surface methodology (RSM) with a quantum-behaved PSO (QPSO) operator, was proposed. Then the way to choose the best design parameters of PM among the multi-objective optimization solution sets was proposed. Then the 3D FEA of the optimal design candidates was compared. The comparison results showed that the proposed method can obtain the best combination of the geometric parameters of reducing the PM volume and increasing the thrust.

  15. Scanning slit for HIE-ISOLDE: vibrations test (linear motion actuator from UHV design, MAXON brushless motor, speed = 10 mm/s)

    CERN Document Server

    Bravin, E; Sosa, A

    2014-01-01

    This report summarizes the results of a series of tests performed on the prototype HIE-ISOLDE diagnostic box (HIE-DB) regarding the vibrations and drifts in the transverse position of the scanning blade while moving in and out of beam path in the HIE-ISOLDE short box prototype. To monitor the transverse position of the blade, a series of 0.1 mm diameter holes were drilled on it and their positions were tracked with an optical system. The linear motion actuator was acquired from UHV design (model LSM38-150-SS), and it was adapted to be driven by a brushless EC motor from MAXON. The speed of the scanning blade during the tests was 10 mm/s. The transverse movement of the slit in the direction perpendicular to the movement was lower than 40 m, and is dominated by the displacement of the contact point of the applied force on the lead-screw. An offset on the slit position was observed while changing the direction of movement of the blade, its amplitude being of the order of 30 m. The amplitudes of the displacements...

  16. Optimum Performances for Non-Linear Finite Elements Model of 8/6 Switched Reluctance Motor Based on Intelligent Routing Algorithms

    Directory of Open Access Journals (Sweden)

    Chouaib Labiod

    2017-01-01

    Full Text Available This paper presents torque ripple reduction with speed control of 8/6 Switched Reluctance Motor (SRM by the determination of the optimal parameters of the turn on, turn off angles Theta_(on, Theta_(off, and the supply voltage using Particle Swarm Optimization (PSO algorithm and steady state Genetic Algorithm (ssGA. With SRM model, there is difficulty in the control relapsed into highly non-linear static characteristics. For this, the Finite Elements Method (FEM has been used because it is a powerful tool to get a model closer to reality. The mechanism used in this kind of machine control consists of a speed controller in order to determine current reference which must be produced to get the desired speed, hence, hysteresis controller is used to compare current reference with current measured up to achieve switching signals needed in the inverter. Depending on this control, the intelligent routing algorithms get the fitness equation from torque ripple and speed response so as to give the optimal parameters for better results. Obtained results from the proposed strategy based on metaheuristic methods are compared with the basic case without considering the adjustment of specific parameters. Optimized results found clearly confirmed the ability and the efficiency of the proposed strategy based on metaheuristic methods in improving the performances of the SRM control considering different torque loads.

  17. Sugeno-Fuzzy Expert System Modeling for Quality Prediction of Non-Contact Machining Process

    Science.gov (United States)

    Sivaraos; Khalim, A. Z.; Salleh, M. S.; Sivakumar, D.; Kadirgama, K.

    2018-03-01

    Modeling can be categorised into four main domains: prediction, optimisation, estimation and calibration. In this paper, the Takagi-Sugeno-Kang (TSK) fuzzy logic method is examined as a prediction modelling method to investigate the taper quality of laser lathing, which seeks to replace traditional lathe machines with 3D laser lathing in order to achieve the desired cylindrical shape of stock materials. Three design parameters were selected: feed rate, cutting speed and depth of cut. A total of twenty-four experiments were conducted with eight sequential runs and replicated three times. The results were found to be 99% of accuracy rate of the TSK fuzzy predictive model, which suggests that the model is a suitable and practical method for non-linear laser lathing process.

  18. A novel non-contact profiler design for measuring synchrotron radiation mirrors

    International Nuclear Information System (INIS)

    Lin, Yao; Takacs, P.Z.; Furenlid, K.; DeBiasse, R.A.; Wang, Run-Wen

    1990-08-01

    A novel optical profiler is described in this paper for measurement of surface profiles of synchrotron radiation (SR) mirrors. The measurement is based on a combination of an optical heterodyne technique and a precise phase measurement procedure without a reference surface. A Zeeman two-frequency He-Ne laser is employed as the light source. The common-path optical system, which uses a birefringent lens as the beam splitter, minimizes the effects of air turbulence, sample vibration and temperature variation. A special autofocus system allows the profiler to measure the roughness and shape of a sample surface. The optical system is mounted on a large linear air-bearing slide, and is capable of scanning over distances covering the spatial period range from several microns to nearly one meter with a high measurement accuracy. 9 refs., 5 figs

  19. A non-contact technique for evaluation of elastic structures at large stand-off distances: applications to classification of fluids in steel vessels.

    Science.gov (United States)

    Kaduchak, G; Sinha, D N; Lizon, D C; Kelecher, M J

    2000-01-01

    A novel technique for non-contact evaluation of structures in air at large stand-off distances (on the order of several meters) has been developed. It utilizes a recently constructed air-coupled, parametric acoustic array to excite the resonance vibrations of elastic, fluid-filled vessels. The parametric array is advantageous for NDE applications in that it is capable of producing a much narrower beamwidth and broader bandwidth than typical devices that operate under linear acoustic principles. In the present experiments, the array operates at a carrier frequency of 217 kHz, and the sound field several meters from the source is described spectrally by the envelope of the drive voltage. An operating bandwidth of more than 25 kHz at a center frequency of 15 kHz is demonstrated. For the present application, the array is used to excite vibrations of fluid-filled, steel containers at stand-off distances of greater than 3 m. The vibratory response of a container is detected with a laser vibrometer in a monostatic configuration with the acoustic source. By analyzing the change in the response of the lowest order, antisymmetric Lamb wave as the interior fluid loading conditions of the container are changed, the fluid contained within the steel vessel is classified.

  20. Non-contact versus contact-based sensing methodologies for in-home upper arm robotic rehabilitation.

    Science.gov (United States)

    Howard, Ayanna; Brooks, Douglas; Brown, Edward; Gebregiorgis, Adey; Chen, Yu-Ping

    2013-06-01

    In recent years, robot-assisted rehabilitation has gained momentum as a viable means for improving outcomes for therapeutic interventions. Such therapy experiences allow controlled and repeatable trials and quantitative evaluation of mobility metrics. Typically though these robotic devices have been focused on rehabilitation within a clinical setting. In these traditional robot-assisted rehabilitation studies, participants are required to perform goal-directed movements with the robot during a therapy session. This requires physical contact between the participant and the robot to enable precise control of the task, as well as a means to collect relevant performance data. On the other hand, non-contact means of robot interaction can provide a safe methodology for extracting the control data needed for in-home rehabilitation. As such, in this paper we discuss a contact and non-contact based method for upper-arm rehabilitation exercises that enables quantification of upper-arm movements. We evaluate our methodology on upper-arm abduction/adduction movements and discuss the advantages and limitations of each approach as applied to an in-home rehabilitation scenario.

  1. Design and Optimal Research of a Non-Contact Adjustable Magnetic Adhesion Mechanism for a Wall-Climbing Welding Robot

    Directory of Open Access Journals (Sweden)

    Minghui Wu

    2013-01-01

    Full Text Available Wall-climbing welding robots (WCWRs can replace workers in manufacturing and maintaining large unstructured equipment, such as ships. The adhesion mechanism is the key component of WCWRs. As it is directly related to the robot's ability in relation to adsorbing, moving flexibly and obstacle-passing. In this paper, a novel non-contact adjustably magnetic adhesion mechanism is proposed. The magnet suckers are mounted under the robot's axils and the sucker and wall are in non-contact. In order to pass obstacles, the sucker and the wheel unit can be pulled up and pushed down by a lifting mechanism. The magnetic adhesion force can be adjusted by changing the height of the gap between the sucker and the wall by the lifting mechanism. In order to increase the adhesion force, the value of the sucker's magnetic energy density (MED is maximized by optimizing the magnet sucker's structure parameters with a finite element method. Experiments prove that the magnetic adhesion mechanism has enough adhesion force and that the WCWR can complete wall-climbing work within a large unstructured environment.

  2. Air-coupled acoustic radiation force for non-contact generation of broadband mechanical waves in soft media

    Energy Technology Data Exchange (ETDEWEB)

    Ambroziński, Łukasz [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); AGH University of Science and Technology, Krakow 30059 (Poland); Pelivanov, Ivan, E-mail: ivanp3@uw.edu [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Faculty of Physics, Moscow State University, Moscow 119991 (Russian Federation); Song, Shaozhen; Yoon, Soon Joon; Gao, Liang; O' Donnell, Matthew [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Li, David [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Department of Chemical Engineering, University of Washington Seattle, Washington 98195 (United States); Shen, Tueng T.; Wang, Ruikang K. [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Department of Ophthalmology, University of Washington, Seattle, Washington 98104 (United States)

    2016-07-25

    A non-contact method for efficient, non-invasive excitation of mechanical waves in soft media is proposed, in which we focus an ultrasound (US) signal through air onto the surface of a medium under study. The US wave reflected from the air/medium interface provides radiation force to the medium surface that launches a transient mechanical wave in the transverse (lateral) direction. The type of mechanical wave is determined by boundary conditions. To prove this concept, a home-made 1 MHz piezo-ceramic transducer with a matching layer to air sends a chirped US signal centered at 1 MHz to a 1.6 mm thick gelatin phantom mimicking soft biological tissue. A phase-sensitive (PhS)-optical coherence tomography system is used to track/image the mechanical wave. The reconstructed transient displacement of the mechanical wave in space and time demonstrates highly efficient generation, thus offering great promise for non-contact, non-invasive characterization of soft media, in general, and for elasticity measurements in delicate soft tissues and organs in bio-medicine, in particular.

  3. Portable Piezospectroscopy system: non-contact in-situ stress sensing through high resolution photo-luminescent mapping

    International Nuclear Information System (INIS)

    Hanhan, I.; Durnberg, E.; Freihofer, G.; Akin, P.; Raghavan, S.

    2014-01-01

    Through the piezospectroscopic effect, certain photo-luminescent materials, once excited with a laser, produce spectral emissions which are sensitive to the stress or strain that the material experiences. A system that utilizes the piezospectroscopic effect for non-contact stress detection over a material's surface can capture important information on the evolution of mechanical response under various conditions. Therefore, the components necessary for piezospectroscopic mapping and analysis have now been integrated into a versatile and transportable system that can be used with photo-luminescent materials in any load frame or on a variety of structures. This system combines compact hardware components such as a portable laser source, fiber optics, spectrograph, charge-coupled device (CCD), and an X-Y-Z stage (with focusing capabilities) with a series of data analysis algorithms capable of analyzing and outputting high resolution photo-luminescent (PL) maps on-site. Through a proof of concept experiment using a compressed polycrystalline alumina sample with sharp machined corners, this system successfully captured high resolution PL maps with a step size of 28.86μm/pixel and located high stress concentrations in critical areas, which correlated closely with the results of a finite element model. This work represents an important step in advancing the portability of piezospectroscopy for in-situ and non-contact stress detection. The instrumentation developed here has strong implications for the future of non-destructive evaluation and non-invasive structural health monitoring

  4. Non-contact assessment of COD and turbidity concentrations in water using diffuse reflectance UV-Vis spectroscopy.

    Science.gov (United States)

    Agustsson, Jon; Akermann, Oliver; Barry, D Andrew; Rossi, Luca

    2014-08-01

    Water contamination is an important environmental concern underlining the need for reliable real-time information on contaminant concentrations in natural waters. Here, a new non-contact UV-Vis spectroscopic approach for monitoring contaminants in water, and especially wastewater, is proposed. Diffuse reflectance UV-Vis spectroscopy was applied to measure simultaneously the chemical oxygen demand (COD) and turbidity (TUR) concentrations in water. The measurements were carried out in the wavelength range from 200-1100 nm. The measured spectra were analysed using partial-least-squares (PLS) regression. The correlation coefficient between the measured and the reference concentrations of COD and TUR in the water samples were R(2) = 0.85 and 0.96, respectively. These results highlight the potential of non-contact UV-Vis spectroscopy for the assessment of water contamination. A system built on the concept would be able to monitor wastewater pollution continuously, without the need for laborious sample collection and subsequent laboratory analysis. Furthermore, since no parts of the system are in contact with the wastewater stream the need for maintenance is minimised.

  5. Effect of water desorption on the rheology and dynamic response of human hair to a non-contact impact.

    Science.gov (United States)

    Jamart, J; Djaghloul, M; Bergheau, J M; Zahouani, H

    2015-06-01

    Human hair is a non-homogeneous complex material made of keratin fibers oriented along the longitudinal axis which offer anisotropic mechanical properties. Nowadays, it is possible to measure the mechanical properties of hairs with the classical tests, but most often, these tests are destructive and make hard to measure the influence of some external factors or treatments on the behavior of a same hair fiber. In the current paper, vibrations induced by a non-contact impact have been utilized as a representative response of the mechanical behavior of hair. The characteristics of the vibratory response allow measuring the variation in the mechanical properties and the instantaneous effect of an external factor on the properties of a same sample. First, load relaxation tests have been performed on hair samples after moisturization and for different times of an air-drying process in order to characterize the change in the visco-elastic behavior of hair during the water desorption. Other hair samples have been tested with our non-contact impact and vibration technique in order to observe the change in the vibratory response during the water desorption. The vibratory response has then been correlated to the mechanical properties of the hair fiber. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. A New Method to Detect Driver Fatigue Based on EMG and ECG Collected by Portable Non-Contact Sensors

    Directory of Open Access Journals (Sweden)

    Lin Wang

    2017-11-01

    Full Text Available Recently, detection and prediction on driver fatigue have become interest of research worldwide. In the present work, a new method is built to effectively evaluate driver fatigue based on electromyography (EMG and electrocardiogram (ECG collected by portable real-time and non-contact sensors. First, under the non-disturbance condition for driver’s attention, mixed physiological signals (EMG, ECG and artefacts are collected by non-contact sensors located in a cushion on the driver’s seat. EMG and ECG are effectively separated by FastICA, and de-noised by empirical mode decomposition (EMD. Then, three physiological features, complexity of EMG, complexity of ECG, and sample entropy (SampEn of ECG, are extracted and analysed. Principal components are obtained by principal components analysis (PCA and are used as independent variables. Finally, a mathematical model of driver fatigue is built, and the accuracy of the model is up to 91%. Moreover, based on the questionnaire, the calculation results of model are consistent with real fatigue felt by the participants. Therefore, this model can effectively detect driver fatigue.

  7. High spatial and temporal resolution measurement of mechanical properties in hydrogels by non-contact laser excitation

    Directory of Open Access Journals (Sweden)

    N. Hosoya

    2016-09-01

    Full Text Available Gels have received increased attention as potential materials for biological materials because they can exhibit similar mechanical properties. One obstacle for using gels is that their mechanical properties are significantly altered by defects, such as an inhomogeneous crosslink density distribution. If these defects could be detected and the values and spatial distributions of mechanical properties in the gel could be determined, it would be possible to apply gels for several fields. To achieve the high spatial and temporal resolution measurement of mechanical properties in hydrogels, in our method, a conventional contact excitation device is replaced with a non-contact excitation using laser ablation for the input and magnetic resonance elastography to measure stress waves is replaced with the Schlieren method with a high-speed camera. Magnetic resonance elastography is a local measurement technique, and consequently, requires a lot of time to characterize a sample, as well as does not have sufficient spatial resolution to obtain a broad range of elasticity coefficients of gels. We use laser ablation to apply non-contact impulse excitations to gels to generate stress waves inside them. We can determine mechanical properties of gels using the stress waves’ propagation velocity.

  8. Dynamic Behavior Analysis of Non-Contacting Hydrodynamic Finger Seal Based on Fluid-Solid-Interaction Method

    Directory of Open Access Journals (Sweden)

    Su Hua

    2018-01-01

    Full Text Available Finger seal is an advanced compliant seal and can be utilized to separate high (HP and low pressure (LP zones in high speed rotating shaft environment. The work to be presented concerns the dynamic behavior of a repetitive section of a two-layer finger seal with high-and padded low-pressure laminates. The dynamic performance of the finger seal are analyzed by the coupled fluid-solid-interaction (FSI simulations. By using the commercial software ANSYS-CFX, the numerical simulation results of interactions between the gas flow and fingers structural deformation are described when the radial periodic excitation from the shaft applies to the finger seal. And the gas film loading capacity, gas film stiffness and leakage varied with time are put forward in different working conditions. Compared with the dynamic performance analysis results based on equivalent dynamic method, the FSI dynamic analysis shows some different characteristics which are more accordance with actual circumstance. Moreover, it is shown that under low pressure differential and high rotation speed the non-contacting finger seal with advance features both in sealing effectiveness and potential unlimited life span can be obtained by rational structure design. But for the non-contacting finger seal with circumferential convergent pad working in high pressure and low rotating speed conditions, it is difficult to improve the sealing performance by the way of changing the structure parameters of finger seal. It is because the high pressure plays a major role on this sealing situation.

  9. Efficacy Evaluation of a non-contact automatic articulating paper dispenser in controlling articulating paper microbial contamination.

    Science.gov (United States)

    Li, Yajin; Chen, Litong; Yuan, Fusong; Li, Yugui; Zhou, Yongsheng; Sun, Yuchun

    2017-05-03

    This study is to quantitatively evaluate the efficacy of using a non-contact automatic articulating paper dispenser for reducing microbial articulating paper contamination. Articulating papers in four-handed mode, non-four-handed mode, and via an automatic articulating paper dispenser were evaluated. An adenosine triphosphate bioluminescence assay was used to quantitatively measure the relative light unit (RLU) values of the rest unused articulating papers in the same package to detect contamination at 4 time points, and triplicate examinations were performed for all three methods. The RLUs were recorded, compared, and evaluated. For four-handed mode (n = 36), the RLUs at the four time points were 2.44, 32.89, 37.89, and 27.22, with a satisfactory rate of 94%. The RLUs for non-four-handed mode (n = 36) were 2.22, 286.44, 299.44, and 493.56, with a satisfactory rate of 36%. The RLUs for using the automatic dispenser (n = 36) were all 0 with a satisfactory rate of 100%. The satisfactory rates were significantly different among three methods. No significant differences were observed in the satisfactory rates for the four time points samples. Contact by gloved hands can cause severe biological contamination of articulating paper. However, by using standard four-handed mode or a non-contact automatic articulating paper dispenser, contamination can be controlled.

  10. Rapid, non-destructive and non-contact inspection of solid foods by means of photothermal radiometry; thermal effusivity and initial heating coefficient

    NARCIS (Netherlands)

    Gijsbertsen, A.; Bicanic, D.D.; Gielen, J.L.W.; Chirtoc, M.

    2004-01-01

    CO2-laser photothermal radiometry (PTR) was demonstrated to be suitable for the nondestructive and non-contact characterization (both optical and thermal) of solid phase agricultural commodities (fres vegetables, fruits) and confectionery products (candy).

  11. Range of motion and radiographic analysis of the hip in patients with contact and non-contact anterior cruciate ligament injury.

    Science.gov (United States)

    Lopes, Osmar Valadão; Gomes, João Luiz Ellera; de Freitas Spinelli, Leandro

    2016-09-01

    To compare the range of motion (ROM) and radiography of the hip joints in male patients with contact anterior cruciate ligament (ACL) injury and non-contact ACL injury. ROM of the ipsilateral hip was evaluated in 35 male patients with contact ACL injury (contact group) and compared to that of 45 male patients with a non-contact ACL injury (non-contact group). Radiographic evaluation of hip joints was also performed to assess the presence of cam and pincer-type deformity . ROM of the hip joint was statistically higher in patients with contact ACL injury. The average sum of hip rotation in the non-contact group was 66.1 ± 8.4° compared to 79.4 ± 10.6° for the contact group (p hip rotation hip. Individuals with contact ACL injury had greater ROM of the hip joints than those with non-contact ACL injury. The presence of cam or pincer deformity was similar in both groups and was not related to decreased ROM of the hip joints. These findings may assist the surgeons to identify new risk factors for non-contact ACL injury and, additionally, develop prevention program of injury. III.

  12. Quantifying non-contact tip-sample thermal exchange parameters for accurate scanning thermal microscopy with heated microprobes

    Science.gov (United States)

    Wilson, Adam A.; Borca-Tasciuc, Theodorian

    2017-07-01

    Simplified heat-transfer models are widely employed by heated probe scanning thermal microscopy techniques for determining thermal conductivity of test samples. These parameters have generally been assumed to be independent of sample properties; however, there has been little investigation of this assumption in non-contact mode, and the impact calibration procedures have on sample thermal conductivity results has not been explored. However, there has been little investigation of the commonly used assumption that thermal exchange parameters are sample independent in non-contact mode, or of the impact calibration procedures have on sample thermal conductivity results. This article establishes conditions under which quantitative, localized, non-contact measurements using scanning thermal microscopy with heated microprobes may be most accurately performed. The work employs a three-dimensional finite element (3DFE) model validated using experimental results and no fitting parameters, to determine the dependence of a heated microprobe thermal resistance as a function of sample thermal conductivity at several values of probe-to-sample clearance. The two unknown thermal exchange parameters were determined by fitting the 3DFE simulated probe thermal resistance with the predictions of a simplified probe heat transfer model, for two samples with different thermal conductivities. This calibration procedure known in experiments as the intersection method was simulated for sample thermal conductivities in the range of 0.1-50 W m-1 K-1 and clearance values in the 260-1010 nm range. For a typical Wollaston wire microprobe geometry as simulated here, both the thermal exchange radius and thermal contact resistance were found to increase with the sample thermal conductivity in the low thermal conductivity range while they remained approximately constant for thermal conductivities >1 W m-1 K-1, with similar trends reported for all clearance values investigated. It is shown that

  13. Non-contact analysis of the adsorptive ink capacity of nano silica pigments on a printing coating base.

    Science.gov (United States)

    Jiang, Bo; Huang, Yu Dong

    2014-01-01

    Near infrared spectra combined with partial least squares were proposed as a means of non-contact analysis of the adsorptive ink capacity of recording coating materials in ink jet printing. First, the recording coating materials were prepared based on nano silica pigments. 80 samples of the recording coating materials were selected to develop the calibration of adsorptive ink capacity against ink adsorption (g/m2). The model developed predicted samples in the validation set with r2  = 0.80 and SEP = 1.108, analytical results showed that near infrared spectra had significant potential for the adsorption of ink capacity on the recording coating. The influence of factors such as recording coating thickness, mass ratio silica: binder-polyvinyl alcohol and the solution concentration on the adsorptive ink capacity were studied. With the help of the near infrared spectra, the adsorptive ink capacity of a recording coating material can be rapidly controlled.

  14. Non-contact measurement of the coefficient of thermal expansion of Al 6061-T6 with fiber Bragg grating sensors

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, Khazar; Ha, Sung Kyu [Hanyang University, Ansan (Korea, Republic of)

    2014-02-15

    An experimental study describing the non-contact measurement of the coefficient of thermal expansion of an aluminum (Al-6061-T6) specimen with two fiber Bragg grating sensors using a pair of C-lens collimators was carried out. The collimators were used for the free space coupling between the fiber Bragg sensors and the optical sensing interrogator. During the experiment, the wavelength distortion of the optical signals was observed. Consequently, the measured thermal strains were corrected using an estimated collimator correction factor of 0.8466. The coefficient of thermal expansion of the specimen was then calculated to be (22.0 ± 0.1)X10{sup -60} C{sup -1} for every 5 .deg. C step in the range 35 .deg. C ∼ 75 .deg. C, which was in good agreement with the typical value of 23.6X10{sup -60}C{sup -1} for aluminum.

  15. Effect of 0.4% benoxinate hydrochloride on corneal sensitivity, measured using the non-contact corneal aesthesiometer (NCCA).

    Science.gov (United States)

    Murphy, P J; Blades, K J; Patel, S

    1997-12-01

    The Non-Contact Corneal Aesthesiometer (NCCA) was used to monitor the effect of topical anesthesia on corneal sensitivity loss and recovery. In a single masked randomized study, one drop of nonpreserved 0.4% benoxinate hydrochloride was instilled in either the right, left, or both eyes of 20 subjects on separate days, and measurements were made of the central corneal sensitivity in the right eye over a 60-min period. As controls, 10 subjects were retested, without any anesthetic instillation, over the same time period. No significant differences were found between these two benoxinate treatments, nor between the contralateral treatment and controls. Results indicate that there is no contralateral effect of benoxinate anesthesia, and that full recovery does not occur until 60 min after instillation. No effect on the depth and duration of anesthesia was found for iris color.

  16. Non-contact XUV metrology of Ru/B4C multilayer optics by means of Hartmann wavefront analysis.

    Science.gov (United States)

    Ruiz-Lopez, Mabel; Dacasa, Hugo; Mahieu, Benoit; Lozano, Magali; Li, Lu; Zeitoun, Philippe; Bleiner, Davide

    2018-02-20

    Short-wavelength imaging, spectroscopy, and lithography scale down the characteristic length-scale to nanometers. This poses tight constraints on the optics finishing tolerances, which is often difficult to characterize. Indeed, even a tiny surface defect degrades the reflectivity and spatial projection of such optics. In this study, we demonstrate experimentally that a Hartmann wavefront sensor for extreme ultraviolet (XUV) wavelengths is an effective non-contact analytical method for inspecting the surface of multilayer optics. The experiment was carried out in a tabletop laboratory using a high-order harmonic generation as an XUV source. The wavefront sensor was used to measure the wavefront errors after the reflection of the XUV beam on a spherical Ru/B 4 C multilayer mirror, scanning a large surface of approximately 40 mm in diameter. The results showed that the technique detects the aberrations in the nanometer range.

  17. Physical Non-Contact Communication between Microscopic Aquatic Species: Novel Experimental Evidences for an Interspecies Information Exchange

    Directory of Open Access Journals (Sweden)

    Daniel Fels

    2016-01-01

    Full Text Available Previous experiments on physical non-contact communication within same species gave rise to test for this type of communication also across the species border, which was the aim of the present study. It was found that autotrophic unicellular organisms (Euglena viridis, separated by cuvettes, affected the proliferation rate of heterotrophic unicellular organisms (Paramecium caudatum. Further, the heterotrophic unicellular organism affected also the proliferation rate of a multicellular heterotrophic organism (Rotatoria sp. and vice versa. In the case when populations (of Euglena viridis and Paramecium caudatum were shielded against electromagnetic fields in the optical spectrum from each other, no effects were measured. The results may support the notion that the organisation of ecosystems relies also on the exchange of electromagnetic fields from their constituting biosystems.

  18. Application of the HHT Method to the Non-contact Thickness Measurement of an Axially Moving Thin Plate

    Science.gov (United States)

    Wu, Yangfang; Lu, Qianqian; Xia, Chunlin; Ding, Fan

    2017-08-01

    Non-contact thickness measuring systems can be found in a wide spectrum of technologies. In this paper, Hilbert-Huang transform method is used to analyze the real time signals of a measuring system which includes two round conveyor strings carrying a thin plate, a solar wafer as a sample under test. The vibrations of moving strings and the plate, which are sensitive to moving speed and initial tension in the string, are introduced briefly; the relevant analyses should be helpful for the system design. Using EMD-based time-domain filtering and complementary method, thickness variations and error bands are estimated for different cases. The results show that HHT method as an adaptive time-frequency method, should be potential in measurement engineering applications.

  19. A Low-Cost, Normally Closed, Solenoid Valve for Non-Contact Dispensing in the Sub-µL Range

    Directory of Open Access Journals (Sweden)

    Peter Koltay

    2013-02-01

    Full Text Available We present a disposable, normally closed, non-contact dispensing valve for the sub-µL range. The miniaturized solenoid valve (diameter: 8 mm, height: 27.25 mm is compatible to standard Luer-Lock interfaces. A highly dynamic actuation principle enables opening times down to 1 ms. The dispensing performance was evaluated for water (η = 1.03 mPas and a 66% (w/w glycerol/water solution (η = 16.98 mPas, at pressures varying from 200 to 800 mbar. The experimentally determined minimal dispensing volume was 163 nL (CV 1.6% for water and 123 nL (CV 4.5% for 66% (w/w glycerol/water. The low-cost polymer valve enables high precision dispensing of liquid volumes down to the lower end of the sub-µL range comparable to high-end non-disposable micro-dispensing valves.

  20. Clinical correlates to laboratory measures for use in non-contact anterior cruciate ligament injury risk prediction algorithm.

    Science.gov (United States)

    Myer, Gregory D; Ford, Kevin R; Khoury, Jane; Succop, Paul; Hewett, Timothy E

    2010-08-01

    Prospective measures of high knee abduction moment during landing identify female athletes at high risk for non-contact anterior cruciate ligament injury. Biomechanical laboratory measurements predict high knee abduction moment landing mechanics with high sensitivity (85%) and specificity (93%). The purpose of this study was to identify correlates to laboratory-based predictors of high knee abduction moment for use in a clinic-based anterior cruciate ligament injury risk prediction algorithm. The hypothesis was that clinically obtainable correlates derived from the highly predictive laboratory-based models would demonstrate high accuracy to determine high knee abduction moment status. Female basketball and soccer players (N=744) were tested for anthropometrics, strength and landing biomechanics. Pearson correlation was used to identify clinically feasible correlates and logistic regression to obtain optimal models for high knee abduction moment prediction. Clinical correlates to laboratory-based measures were identified and predicted high knee abduction moment status with 73% sensitivity and 70% specificity. The clinic-based prediction algorithm, including (Odds Ratio: 95% confidence interval) knee valgus motion (1.43:1.30-1.59 cm), knee flexion range of motion (0.98:0.96-1.01 degrees ), body mass (1.04:1.02-1.06 kg), tibia length (1.38:1.25-1.52 cm) and quadriceps to hamstring ratio (1.70:1.06-2.70) predicted high knee abduction moment status with C statistic 0.81. The combined correlates of increased knee valgus motion, knee flexion range of motion, body mass, tibia length and quadriceps to hamstrings ratio predict high knee abduction moment status in female athletes with high sensitivity and specificity. Utilization of clinically obtainable correlates with the prediction algorithm facilitates high non-contact anterior cruciate ligament injury risk athletes' entry into appropriate interventions with the greatest potential to prevent injury. Copyright (c) 2010

  1. Feasibility on Ultrasonic Velocity using Contact and Non-Contact Nondestructive Techniques for Carbon/Carbon Composites

    Science.gov (United States)

    Im, K. H.; Chang, M.; Hsu, D. K.; Song, S. J.; Cho, H.; Park, J. W.; Kweon, Y. S.; Sim, J. K.; Yang, I. Y.

    2007-03-01

    Advanced materials are to be required to have specific functions associated with extremely environments. One of them is carbon/carbon(C/C) composite material, which has obvious advantages over conventional materials. The C/Cs have become to be utilized as parts of aerospace applications and its low density, high thermal conductivity and excellent mechanical properties at elevated temperatures make it an ideal material for aircraft brake disks. Because of permeation of coupling medium such as water, it is desirable to perform contact-less nondestructive evaluation to assess material properties and part homogeneity. In this work, a C/C composite material was characterized with non-contact and contact ultrasonic methods using a scanner with automatic-data acquisition function. Also through transmission mode was performed because of the main limitation for air-coupled transducers, which is the acoustic impedance mismatch between most materials and air. Especially ultrasonic images and velocities for C/C composite disk brake were compared and found to be consistent to some degree with the non-contact and contact ultrasonic measurement methods. Low frequency through-transmission scans based on both amplitude of the ultrasonic pulse was used for mapping out the material property inhomogeneity. Measured results were compared with those obtained by the dry-coupling ultrasonic UT system and through transmission method in immersion. Finally, feasibility has been found to measure and compare ultrasonic velocities of C/C composites with using the contact/noncontact peak-delay measurement method based on the pulse overlap method.

  2. Scleral Buckling Using a Non-contact Wide-Angle Viewing System with a 25-Gauge Chandelier Endoilluminator.

    Science.gov (United States)

    Jo, Jaehyuck; Moon, Byung Gil; Lee, Joo Yong

    2017-12-01

    To report the outcome of scleral buckling using a non-contact wide-angle viewing system with a 25-gauge chandelier endoilluminator. Retrospective analyses of medical records were performed for 17 eyes of 16 patients with primary rhegmatogenous retinal detachment (RRD) without proliferative vitreoretinopathy who had undergone conventional scleral buckling with cryoretinopexy using the combination of a non-contact wide-angle viewing system and chandelier endoillumination. The patients were eight males and five females with a mean age of 26.8 ± 10.2 (range, 11 to 47) years. The mean follow-up period was 7.3 ± 3.1 months. Baseline best-corrected visual acuity was 0.23 ± 0.28 logarithm of the minimum angle of resolution units. Best-corrected visual acuity at the final visit showed improvement (0.20 ± 0.25 logarithm of the minimum angle of resolution units), but the improvement was not statistically significant (p = 0.722). As a surgery-related complication, there was vitreous loss at the end of surgery in one eye. As a postoperative complication, increased intraocular pressure (four cases) and herpes simplex epithelial keratitis (one case) were controlled postoperatively with eye drops. One case of persistent RRD after primary surgery needed additional vitrectomy, and the retina was postoperatively attached. Scleral buckling with chandelier illumination as a surgical technique for RRD has the advantages of relieving the surgeon's neck pain from prolonged use of the indirect ophthalmoscope and sharing the surgical procedure with another surgical team member. In addition, fine retinal breaks that are hard to identify using an indirect ophthalmoscope can be easily found under the microscope by direct endoillumination. © 2017 The Korean Ophthalmological Society

  3. ACCURACY EVALUATION FOR THE NON-CONTACT DEFECT AREA MEASUREMENT AT THE COMPLEX-SHAPE SURFACES UNDER VIDEOENDOSCOPIC CONTROL

    Directory of Open Access Journals (Sweden)

    A. V. Gorevoy

    2014-07-01

    Full Text Available The problem of non-contact surface defect area measurement at complex-shape objects under videoendoscopic control is considered. Major factors contributing to the measurement uncertainty are analyzed for the first time. The proposed method of accuracy analysis is based on the evaluation of 3D coordinates of surface points from 2D projections under assumption of projective camera model and Mahalanobis distance minimization in the image plane. Expressions for area measurement error caused by sum-of-triangles approximation are obtained analytically for practically important cases of cylindrical and spherical surfaces. It is shown that the magnitude of this error component for a single triangle does not exceed 1% for the real values of parameters of the endoscopic imaging system. Expressions are derived for area measurement uncertainty evaluation on arbitrary shape surfaces, caused by measurement errors of 3D coordinates of individual points with and without a priori information about surface shape. Verification of the obtained expressions with real experiment data showed that area measurement error for a complex figure, given by a set of points, is mainly caused by ignoring the fact that these points belong to the surface. It is proved that the use of a priori information about investigated surface shape, which is often available from the design documentation, in many cases would radically improve the accuracy of surface defects area measurement. The presented results are valid for stereoscopic, shadow and phase methods of video endoscopic measurements and can be effectively used in development of new non-contact measuring endoscopic systems and modernization of existing ones.

  4. The influence of central corneal thickness and age on intraocular pressure measured by pneumotonometry, non-contact tonometry, the Tono-Pen XL, and Goldmann applanation tonometry.

    Science.gov (United States)

    Tonnu, P-A; Ho, T; Newson, T; El Sheikh, A; Sharma, K; White, E; Bunce, C; Garway-Heath, D

    2005-07-01

    To evaluate the influence of central corneal thickness (CCT) on intraocular pressure (IOP) measurements made with the Goldmann applanation tonometer (GAT), Tono-Pen XL, ocular blood flow tonograph (OBF), and Canon TX-10 non-contact tonometer (NCT). CCT was recorded for either eye (randomly selected) of each of 105 untreated patients with ocular hypertension and glaucoma attending the glaucoma research unit at Moorfields Eye Hospital. For each of the selected eyes, IOP was measured with the GAT (two observers), Tono-Pen, OBF, and NCT in a randomised order. The relation of measured IOP and of inter-tonometer differences with CCT and subject age was explored by linear regression analysis. A significant association between measured IOP and CCT was found with each instrument. The change in measured IOP for a 10 mum increase in CCT was 0.28, 0.31, 0.38, and 0.46 for the GAT, Tono-Pen, OBF, and NCT, respectively (all p< or = 0.05). There was a significant association between the NCT/GAT differences and CCT, with a tendency of NCT to overestimate GAT in eyes with thicker corneas. There was a significant association between GAT/Tono-Pen and OBF/Tono-Pen differences and age, with a tendency of GAT and OBF to overestimate the Tono-Pen in eyes of older subjects. IOP measurement by all four methods is affected by CCT. The NCT is affected by CCT significantly more than the GAT. Subject age has a differential effect on the IOP measurements made by the GAT and OBF compared to the Tono-Pen.

  5. The influence of central corneal thickness and age on intraocular pressure measured by pneumotonometry, non-contact tonometry, the Tono-Pen XL, and Goldmann applanation tonometry

    Science.gov (United States)

    Tonnu, P-A; Ho, T; Newson, T; El Sheikh, A; Sharma, K; White, E; Bunce, C; Garway-Heath, D

    2005-01-01

    Aims: To evaluate the influence of central corneal thickness (CCT) on intraocular pressure (IOP) measurements made with the Goldmann applanation tonometer (GAT), Tono-Pen XL, ocular blood flow tonograph (OBF), and Canon TX-10 non-contact tonometer (NCT). Methods: CCT was recorded for either eye (randomly selected) of each of 105 untreated patients with ocular hypertension and glaucoma attending the glaucoma research unit at Moorfields Eye Hospital. For each of the selected eyes, IOP was measured with the GAT (two observers), Tono-Pen, OBF, and NCT in a randomised order. The relation of measured IOP and of inter-tonometer differences with CCT and subject age was explored by linear regression analysis. Results: A significant association between measured IOP and CCT was found with each instrument. The change in measured IOP for a 10 μm increase in CCT was 0.28, 0.31, 0.38, and 0.46 for the GAT, Tono-Pen, OBF, and NCT, respectively (all p⩽0.05). There was a significant association between the NCT/GAT differences and CCT, with a tendency of NCT to overestimate GAT in eyes with thicker corneas. There was a significant association between GAT/Tono-Pen and OBF/Tono-Pen differences and age, with a tendency of GAT and OBF to overestimate the Tono-Pen in eyes of older subjects. Conclusion: IOP measurement by all four methods is affected by CCT. The NCT is affected by CCT significantly more than the GAT. Subject age has a differential effect on the IOP measurements made by the GAT and OBF compared to the Tono-Pen. PMID:15965165

  6. Automated pipeline to analyze non-contact infrared images of the paraventricular nucleus specific leptin receptor knock-out mouse model

    Science.gov (United States)

    Diaz Martinez, Myriam; Ghamari-Langroudi, Masoud; Gifford, Aliya; Cone, Roger; Welch, E. B.

    2015-03-01

    Evidence of leptin resistance is indicated by elevated leptin levels together with other hallmarks of obesity such as a defect in energy homeostasis.1 As obesity is an increasing epidemic in the US, the investigation of mechanisms by which leptin resistance has a pathophysiological impact on energy is an intensive field of research.2 However, the manner in which leptin resistance contributes to the dysregulation of energy, specifically thermoregulation,3 is not known. The aim of this study was to investigate whether the leptin receptor expressed in paraventricular nucleus (PVN) neurons plays a role in thermoregulation at different temperatures. Non-contact infrared (NCIR) thermometry was employed to measure surface body temperature (SBT) of nonanesthetized mice with a specific deletion of the leptin receptor in the PVN after exposure to room (25 °C) and cold (4 °C) temperature. Dorsal side infrared images of wild type (LepRwtwt/sim1-Cre), heterozygous (LepRfloxwt/sim1-Cre) and knock-out (LepRfloxflox/sim1-Cre) mice were collected. Images were input to an automated post-processing pipeline developed in MATLAB to calculate average and maximum SBTs. Linear regression was used to evaluate the relationship between sex, cold exposure and leptin genotype with SBT measurements. Findings indicate that average SBT has a negative relationship to the LepRfloxflox/sim1-Cre genotype, the female sex and cold exposure. However, max SBT is affected by the LepRfloxflox/sim1-Cre genotype and the female sex. In conclusion this data suggests that leptin within the PVN may have a neuroendocrine role in thermoregulation and that NCIR thermometry combined with an automated imaging-processing pipeline is a promising approach to determine SBT in non-anesthetized mice.

  7. Er:YAG laser radiation: contact versus non-contact enamel ablation and sonic-activated bulk composite placement: microleakage evaluation

    Science.gov (United States)

    Dostalova, T.; Jelinkova, H.; Kasparova, M.; Ginzelova, K.; Feberova, J.; Sulc, J.; Nemec, M.; Fibrich, M.; Bradna, P.

    2015-02-01

    Our study aims to analyze the bond after the Er:YAG laser-radiation-prepared cavity was filled with a new kind of bulk-filled composite material. The laser radiation acted in a contact and non-contact mode. The setting for contact ablation was as follows: energy 250 mJ/pulse with a pulse repetition rate 15 Hz, giving an average power of 3.75 W. For non-contact ablation these values were 600 mJ/pulse, 6 Hz, and 3.6 W. Scanning ablation was provided in non-contact mode (1440 pulses/cavity) and the parameters were: energy 300 mJ/pulse, repetition rate 1 Hz, and mean power 0.3 W. Three types of laser cavities were filled with sonic activated composite resin. Four longitudinal sections were prepared after immersion in 5% methylene blue for 24 h. Microleakage was assessed quantitatively by the degree of dye penetration; the data were analyzed by the Fisher exact test with the level of significance set at p treatments prepared similar cavities (5167.31 versus 5356.31 µm). Defocusing of non-contact therapy has a direct influence on the presence of dye penetration microleakage (481.19 versus 611.94 µm). The non-contact scan is a more effective method for laser ablation (8508.05 µm). For that reason the dye penetration (microleakage) is higher (1458.65 µm). These results are statistically significant.

  8. Contact versus non-contact ablation of the artificial enamel caries by Er:YAG and CTH:YAG laser radiation

    Science.gov (United States)

    Dostálová, Tat'jana; Jelínková, Helena; Å ulc, Jan; Němec, Michal; Bučková, Michaela; Kašparová, Magdalena; Miyagi, Mitsunobu

    The aim of study is to compare the ablation effect of contact and non-contact interaction of Er:YAG and CTH:YAG laser radiation with artificial enamel caries lesion. The artificial caries was prepared in intact teeth to simulate demineralized surface and the laser radiation was applied. Contact and non-contact ablation was compared. Two laser systems Er:YAG 2.94 μm and CTH:YAG 2.1 μm were used. The enamel artificial caries were gently removed by laser radiation and flow Sonic fill composite resin was inserted. Scanning electron microscope was use to evaluate the enamel surface.

  9. Association between maximal hamstring strength and hamstring muscle pre-activity during a movement associated with non-contact ACL injury

    DEFF Research Database (Denmark)

    Skov Husted, Rasmus; Bencke, Jesper; Thorborg, Kristian

    2014-01-01

    Introduction Reduced hamstring pre-activity during side-cutting may predispose for non-contact ACL injury. During the last decade resistance training of the lower limb muscles has become an integral part of ACL injury prevention in e.g. soccer and handball. However, it is not known whether a strong...... translate into high levels of muscle pre-activity during movements like the sidecutting maneuver. Thus, other exercise modalities (i.e. neuromuscular training) are needed to optimize hamstring muscle pre-activity during movements associated with non-contact ACL injury....

  10. Association between maximal hamstring muscle strength and hamstring muscle pre-activity during a movement associated with non-contact ACL injury

    DEFF Research Database (Denmark)

    Zebis, M. K.; Sorensen, R. S.; Thorborg, K.

    2015-01-01

    Background: Reduced hamstring pre-activity during sidecutting increases the risk for non-contact ACL injury. During the last decade resistance training of the lower limb muscles has become an integral part ofACLinjury prevention in e.g. soccer and handball. However, it is not known whether a strong...... levels of muscle pre-activity during movements like the sidecutting maneuver. Implications: Other exercise modalities (i.e. neuromuscular training) are needed to optimize hamstring muscle pre-activity during movements associated with non-contact ACL injury....

  11. Development of a Non-Contact, Inductive Depth Sensor for Free-Surface, Liquid-Metal Flows

    Science.gov (United States)

    Bruhaug, Gerrit; Kolemen, Egemen; Fischer, Adam; Hvasta, Mike

    2017-10-01

    This paper details a non-contact based, inductive depth measurement system that can sit behind a layer of steel and measure the depth of the liquid metal flowing over the steel. Free-surface liquid metal depth measurement is usually done with invasive sensors that impact the flow of the liquid metal, or complex external sensors that require lasers and precise alignment. Neither of these methods is suitable for the extreme environment encountered in the diverter region of a nuclear fusion reactor, where liquid metal open channel flows are being investigated for future use. A sensor was developed that used the inductive coupling of a coil to liquid metal to measure the height of the liquid metal present. The sensor was built and tested experimentally, and modeled with finite element modeling software to further understand the physics involved. Future work will attempt to integrate the sensor into the Liquid Metal eXperiment (LMX) at the Princeton Plasma Physics Laboratory for more refined testing. This work was made possible by funding from the Department of Energy for the Summer Undergraduate Laboratory Internship (SULI) program. This work is supported by the US DOE Contract No.DE-AC02-09CH11466.

  12. The non-contact measure of the heart rate variability by laser Doppler vibrometry: comparison with electrocardiography

    Science.gov (United States)

    Cosoli, G.; Casacanditella, L.; Tomasini, E. P.; Scalise, L.

    2016-06-01

    The assessment of the heart rate variability (HRV) is of utmost importance, being one of the most promising markers of the activity of the autonomic nervous system and associated to cardiovascular mortality. Different signals can be used to perform HRV, primarily electrocardiography (ECG), photoplethysmography (PPG), phonocardiography (PCG) or vibrocardiography (VCG), since the fundamental aspect is the individuation of a periodic feature strictly correlated with cardiac activity (i.e. R-peak in ECG or the first sound in PCG). In this work, the authors demonstrate that the VCG performances in HRV analysis are sufficiently accurate if compared to the ones measured by ECG (i.e. standard methodology); moreover, the authors want to prove the feasibility of such measurement in correspondence of different measurement points (i.e. carotid artery—which is the typical VCG measurement point—and the radial artery on the wrist)1. Results show that VCG has a mean deviation of  heart rate (HR) measurement; carotid artery is the most accurate site for the assessment, but also the radial artery is a valid site, even if with a reduced SNR. With regards to HRV parameters, the mean percentage deviation is  <10% in correspondence of carotid artery, and  ≈16% for the radial artery. So, VCG allows for non-contact monitoring of the cardiac activity.

  13. 3D Blade Vibration Measurements on an 80 m Diameter Wind Turbine by Using Non-contact Remote Measurement Systems

    Science.gov (United States)

    Ozbek, Muammer; Rixen, Daniel J.

    Non-contact optical measurement systems photogrammetry and laser interferometry are introduced as cost efficient alternatives to the conventional wind turbine/farm monitoring systems that are currently in use. The proposed techniques are proven to provide an accurate measurement of the dynamic behavior of a 2.5 MW—80 m diameter—wind turbine. Several measurements are taken on the test turbine by using 4 CCD cameras and 1 laser vibrometer and the response of the turbine is monitored from a distance of 220 m. The results of the infield tests and the corresponding analyses show that photogrammetry (also can be called as videogrammetry or computer vision technique) enable the 3D deformations of the rotor to be measured at 33 different points simultaneously with an average accuracy of ±25 mm, while the turbine is rotating. Several important turbine modes can also be extracted from the recorded data. Similarly, laser interferometry (used for the parked turbine only) provides very valuable information on the dynamic properties of the turbine structure. Twelve different turbine modes can be identified from the obtained response data.

  14. Mimicking and Measuring Occlusal Erosive Tooth Wear with the "Rub&Roll" and Non-contact Profilometry.

    Science.gov (United States)

    Ruben, Jan L; Truin, Gert-Jan; Loomans, Bas A C; Huysmans, Marie-Charlotte D N J M

    2018-02-02

    Chewing, drinking, and occasional tooth grinding will result in physiological tooth wear during a lifetime. Extreme challenges, such as bruxism or habitual chewing on foreign objects, may lead to excessive wear. Recently, the role of erosion in accelerating mechanical tooth wear has been recognized, but the interplay between chemical and mechanical wear processes has not been extensively studied. Our laboratory recently introduced a novel oral wear simulation device, the Rub&Roll, that enables the user to perform wear and loading studies separately or simultaneously in an erosive and/or abrasive environment. This manuscript describes an application of the device: the combined mechanical and erosive loading of extracted human (pre)molars in a simulated chewing movement, with a controlled application of force, velocity, fluid, and time, and the application of non-contact profilometry in visualizing and measuring the resulting wear pattern. The occlusal morphology that was created in the experiment with the highest loading level is very similar to the clinical presentation of erosive wear.

  15. Non-contact multi-frequency magnetic induction spectroscopy system for industrial-scale bio-impedance measurement

    International Nuclear Information System (INIS)

    O'Toole, M D; Marsh, L A; Davidson, J L; Tan, Y M; Armitage, D W; Peyton, A J

    2015-01-01

    Biological tissues have a complex impedance, or bio-impedance, profile which changes with respect to frequency. This is caused by dispersion mechanisms which govern how the electromagnetic field interacts with the tissue at the cellular and molecular level. Measuring the bio-impedance spectra of a biological sample can potentially provide insight into the sample’s properties and its cellular structure. This has obvious applications in the medical, pharmaceutical and food-based industrial domains. However, measuring the bio-impedance spectra non-destructively and in a way which is practical at an industrial scale presents substantial challenges. The low conductivity of the sample requires a highly sensitive instrument, while the demands of industrial-scale operation require a fast high-throughput sensor of rugged design. In this paper, we describe a multi-frequency magnetic induction spectroscopy (MIS) system suitable for industrial-scale, non-contact, spectroscopic bio-impedance measurement over a bandwidth of 156 kHz–2.5 MHz. The system sensitivity and performance are investigated using calibration and known reference samples. It is shown to yield rapid and consistently sensitive results with good long-term stability. The system is then used to obtain conductivity spectra of a number of biological test samples, including yeast suspensions of varying concentration and a range of agricultural produce, such as apples, pears, nectarines, kiwis, potatoes, oranges and tomatoes. (paper)

  16. Uncertainties in forces extracted from non-contact atomic force microscopy measurements by fitting of long-range background forces

    Directory of Open Access Journals (Sweden)

    Adam Sweetman

    2014-04-01

    Full Text Available In principle, non-contact atomic force microscopy (NC-AFM now readily allows for the measurement of forces with sub-nanonewton precision on the atomic scale. In practice, however, the extraction of the often desired ‘short-range’ force from the experimental observable (frequency shift is often far from trivial. In most cases there is a significant contribution to the total tip–sample force due to non-site-specific van der Waals and electrostatic forces. Typically, the contribution from these forces must be removed before the results of the experiment can be successfully interpreted, often by comparison to density functional theory calculations. In this paper we compare the ‘on-minus-off’ method for extracting site-specific forces to a commonly used extrapolation method modelling the long-range forces using a simple power law. By examining the behaviour of the fitting method in the case of two radically different interaction potentials we show that significant uncertainties in the final extracted forces may result from use of the extrapolation method.

  17. Kinematic self-calibration of non-contact five-axis measuring machine using improved genetic algorithm

    Science.gov (United States)

    Fei, Zhigen; Xu, Xiaojie; Xiao, Yanqiu; Meier, Nicolas; Georgiadis, Anthimos

    2016-02-01

    A novel non-contact, five-axis measuring machine with high measurement accuracy of workpiece dimensions is introduced in this paper. The kinematic model, as well as the kinematic error model, is developed. A self-calibration method using a steel ball is proposed to improve the measurement accuracy in the workspace. The calibration process is low-budget and easy-to-operate due to the fact there is no need to rely on other instruments or devices except for the laser probe carried by the measuring machine itself. The objective function is defined in terms of center-to-center distance deviation, namely the theoretical ball center and tested ball center, and to improve the speed of the convergence rate and to increase the optimization accuracy of the genetic algorithm. The simulation and practical experiments both illustrate the feasibility and validity of the proposed kinematic model and self-calibration method. Finally, the actual measurement results of a Φ12 sphere illustrate that the measurement accuracy of this machine has improved greatly by using calibrated parameters against nominal parameters.

  18. Non-contact measurement of tremor for the characterisation of Parkinsonian individuals: comparison between Kinect and Laser Doppler vibrometer

    Science.gov (United States)

    Casacanditella, L.; Cosoli, G.; Ceravolo, MG; Tomasini, EP

    2017-08-01

    Parkinson’s disease is a progressive neurodegenerative disorder affecting the central nervous system. One of its main and most evident symptoms is the tremor, which usually manifests at rest with varying intensity during time. An important diagnostic challenge is the differential diagnosis between Parkinson’s disease and the other most widely represented tremor syndrome, i.e. Essential (or senile) tremor. At present there are no standard methods for the quantification of tremor and the diagnosis of both Parkinson’s disease and Essential tremor is mainly done on the base of clinical criteria and by using rating scales. The aim of this work is to objectively and non-invasively assess the tremor linked to the quoted diseases, using non-contact techniques: Laser Doppler Vibrometer (LDV) and Kinect for Windows device. Two subjects with Parkinson’s disease and one with Essential tremor were tested in different conditions: at rest, during a cognitive task, with forward stretched arms and in “Wing position”. The results from data processing in terms of tremor frequency seem to be comparable, with a mean deviation of 0.31 Hz. Furthermore, the values computed are consistent with what is stated in the literature (i.e. 4-12 Hz). So, both LDV and Kinect device can be considered suitable to be used as an objective means for the assessment and monitoring of Parkinson’s disease tremor, helping the clinician in the choice of the most suitable treatment for the patients.

  19. [Study of cytogenetic and cytotoxic effect of non-contact electrochemically-activated waters in the five organs of rats].

    Science.gov (United States)

    Sycheva, L P; Mikhaĭlova, R I; Beliaeva, N N; Zhurkov, V S; Iurchenko, V V; Savostikova, O N; Alekseeva, A V; Kribtsova, E K; Kovalenko, M A; Akhal'tseva, L V; Sheremet'eva, S M; Iurtseva, N A; Murav'eva, L V; Kamenetskaia, D B

    2014-01-01

    For the first time the multiorgan karyological analysis of five organs of rats was applied for the study of the cytogenetic and cytotoxic action of the four types of non-contact electrochemically activated water in the 30-days in vivo experiment. The effects of investigated waters were not detected in bone marrow polychromatic erythrocytes. "Anolyte" (ORP = -362 mV) did not have a negative effect on rats. "Catholyte-5" (ORP = +22 mV) and "Catholyte-25" (ORP = -60 mV) induced cytogenetic abnormalities in the bladder and fore stomach. The same catholytes and "Catholyte-40" (ORP = -10 mV) changed the proliferation indices: increased the mitotic index in the fore stomach epithelium and reduced the frequency of binucleated cells in the fore stomach, bladder and lungs. The increase in the rate of cells with cytogenetic abnormalities on the background of the promotion of mitotic activity can be considered as a manifestation of the negative effect, typical for catolytes, but the effect of each out of them has its own features.

  20. A comparison of muscle damage, soreness and performance following a simulated contact and non-contact team sport activity circuit.

    Science.gov (United States)

    Singh, Tarveen K R; Guelfi, Kym J; Landers, Grant; Dawson, Brian; Bishop, David

    2011-09-01

    The aim was to compare the effect of a simulated team sport activity circuit (reflective of the activity demands of Australian football) either with or without body 'contact' on muscle soreness, damage, and performance when the circuit was repeated 48 h later. Eleven male, team-sport athletes completed a 'non-contact' (NCON) and a 'contact' (CON) version of the team sport activity circuit in a crossover design with at least 1 week between trials. The effect of CON and NCON on repeated 15m sprint and vertical jump performance was assessed by completing the same version of the circuit 48 h after the initial trial. The effect on perceived soreness and blood markers of muscle damage and inflammation was also determined. Subsequent performance was affected to a greater extent by CON, with both best and mean sprint times significantly slower 48h following CON (psoreness and pressure sensitivity were elevated following both NCON and CON (psoreness was greater with CON (p=0.012). Both CON and NCON resulted in elevated serum creatine kinase, myoglobin and lactate dehydrogenase, while c-reactive protein increased following CON but not NCON. In conclusion, Greater perceived soreness and decrements in performance of the simulated team sport activity circuit when repeated 48 h later were observed following CON. Copyright © 2011 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. Non-contact and Unrestrained Respiration Monitoring System for Sleeping Person Using Near-infrared Bright Spots Matrix Irradiation

    Science.gov (United States)

    Aoki, Hirooki; Aoki, Hiroichi; Nakajima, Masato

    Measurement of biological information appears to be an effective method to obtain an understanding of health conditions measures to maintain and improve the health of elderly people. However, every conventional bioinstrumentation technique imposes a sense of restraint that results in aversion against measurements that would last over consecutive days. To solve this problem, we propose a system for monitoring the respiration of sleepers, and it uses a fiber grating vision sensor, which is a type of optical range finder, to achieve non-contact and unrestrained monitoring. The signals obtained by the system include the respiration rate, shifts of the ventilation, and the body movement interval of the sleeper. The information enables to investigate the stability of the sleeper throughout the night. We examined the measuring accuracy, validity, and effectiveness of our proposed system. And all-night monitoring performed at elderly care facility revealed that respiratory disturbances during sleep occurred in many of the residents and that sleep apnea is a common syndrome, especially among residents who have senile dementia or have had a stroke. We were able to carry out the all-night monitoring with this system for a total of about 370 times, according to our schedule, without experiencing any failure, accident, or interruption. Our proposed system is highly effective for monitoring elderly dementia patients who are likely to become uncooperative during measurement with existing monitoring methods that use certain amounts of restraint.

  2. Design of a machine for the universal non-contact measurement of large free-form optics with 30 nm uncertainty

    NARCIS (Netherlands)

    Henselmans, R.; Rosielle, P.C.J.N.; Steinbuch, M.; Saunders, I.; Bergmans, R.

    2005-01-01

    A new universal non-contact measurement machine design for measuring free-form optics with 30 nm expanded uncertainty is presented. In the cylindrical machine concept, an optical probe with 5 mm range is positioned over the surface by a motion system. Due to a 2nd order error effect when measuring

  3. Development of a baby friendly non-contact method for measuring vital signs: First results of clinical measurements in an open incubator at a neonatal intensive care unit

    Science.gov (United States)

    Klaessens, John H.; van den Born, Marlies; van der Veen, Albert; Sikkens-van de Kraats, Janine; van den Dungen, Frank A.; Verdaasdonk, Rudolf M.

    2014-02-01

    For infants and neonates in an incubator vital signs, such as heart rate, breathing, skin temperature and blood oxygen saturation are measured by sensors and electrodes sticking to the skin. This can damage the vulnerable skin of neonates and cause infections. In addition, the wires interfere with the care and hinder the parents in holding and touching the baby. These problems initiated the search for baby friendly 'non-contact' measurement of vital signs. Using a sensitive color video camera and specially developed software, the heart rate was derived from subtle repetitive color changes. Potentially also respiration and oxygen saturation could be obtained. A thermal camera was used to monitor the temperature distribution of the whole body and detect small temperature variations around the nose revealing the respiration rate. After testing in the laboratory, seven babies were monitored (with parental consent) in the neonatal intensive care unit (NICU) simultaneously with the regular monitoring equipment. From the color video recordings accurate heart rates could be derived and the thermal images provided accurate respiration rates. To correct for the movements of the baby, tracking software could be applied. At present, the image processing was performed off-line. Using narrow band light sources also non-contact blood oxygen saturation could be measured. Non-contact monitoring of vital signs has proven to be feasible and can be developed into a real time system. Besides the application on the NICU non-contact vital function monitoring has large potential for other patient groups.

  4. Non-contact video-based vital sign monitoring using ambient light and auto-regressive models

    International Nuclear Information System (INIS)

    Tarassenko, L; Villarroel, M; Guazzi, A; Jorge, J; Clifton, D A; Pugh, C

    2014-01-01

    Remote sensing of the reflectance photoplethysmogram using a video camera typically positioned 1 m away from the patient’s face is a promising method for monitoring the vital signs of patients without attaching any electrodes or sensors to them. Most of the papers in the literature on non-contact vital sign monitoring report results on human volunteers in controlled environments. We have been able to obtain estimates of heart rate and respiratory rate and preliminary results on changes in oxygen saturation from double-monitored patients undergoing haemodialysis in the Oxford Kidney Unit. To achieve this, we have devised a novel method of cancelling out aliased frequency components caused by artificial light flicker, using auto-regressive (AR) modelling and pole cancellation. Secondly, we have been able to construct accurate maps of the spatial distribution of heart rate and respiratory rate information from the coefficients of the AR model. In stable sections with minimal patient motion, the mean absolute error between the camera-derived estimate of heart rate and the reference value from a pulse oximeter is similar to the mean absolute error between two pulse oximeter measurements at different sites (finger and earlobe). The activities of daily living affect the respiratory rate, but the camera-derived estimates of this parameter are at least as accurate as those derived from a thoracic expansion sensor (chest belt). During a period of obstructive sleep apnoea, we tracked changes in oxygen saturation using the ratio of normalized reflectance changes in two colour channels (red and blue), but this required calibration against the reference data from a pulse oximeter. (paper)

  5. Non-contact measurement of partial gas pressure and distribution of elemental composition using energy-resolved neutron imaging

    Science.gov (United States)

    Tremsin, A. S.; Losko, A. S.; Vogel, S. C.; Byler, D. D.; McClellan, K. J.; Bourke, M. A. M.; Vallerga, J. V.

    2017-01-01

    Neutron resonance absorption imaging is a non-destructive technique that can characterize the elemental composition of a sample by measuring nuclear resonances in the spectrum of a transmitted beam. Recent developments in pixelated time-of-flight imaging detectors coupled with pulsed neutron sources pose new opportunities for energy-resolved imaging. In this paper we demonstrate non-contact measurements of the partial pressure of xenon and krypton gases encapsulated in a steel pipe while simultaneously passing the neutron beam through high-Z materials. The configuration was chosen as a proof of principle demonstration of the potential to make non-destructive measurement of gas composition in nuclear fuel rods. The pressure measured from neutron transmission spectra (˜739 ± 98 kPa and ˜751 ± 154 kPa for two Xe resonances) is in relatively good agreement with the pressure value of ˜758 ± 21 kPa measured by a pressure gauge. This type of imaging has been performed previously for solids with a spatial resolution of ˜ 100 μm. In the present study it is demonstrated that the high penetration capability of epithermal neutrons enables quantitative mapping of gases encapsulate within high-Z materials such as steel, tungsten, urania and others. This technique may be beneficial for the non-destructive testing of bulk composition of objects (such as spent nuclear fuel assemblies and others) containing various elements opaque to other more conventional imaging techniques. The ability to image the gaseous substances concealed within solid materials also allows non-destructive leak testing of various containers and ultimately measurement of gas partial pressures with sub-mm spatial resolution.

  6. The role of domestic tap water on Acanthamoeba keratitis in non-contact lens wearers and validation of laboratory methods.

    Science.gov (United States)

    Koltas, Ismail Soner; Eroglu, Fadime; Erdem, Elif; Yagmur, Meltem; Tanır, Ferdi

    2015-09-01

    Acanthamoeba is increasingly recognized as an important cause of keratitis in non-contact lens wearers while contact lens wear is the leading risk factor for Acanthamoeba keratitis (AK). It is unlikely that the Acanthamoeba colonization is a feature which is effective only in patient's homes with infectious keratitis since the organism has been isolated from domestic tap water. Two hundred and thirty-one (231) corneal scrapings were taken from infectious keratitis cases, and four contact lens solutions and domestic tap waters were taken from 22 out of 44 AK-diagnosed patient's homes. Microscopic examination, culture, PCR, real-time PCR and DNA sequencing analyses were used for AK-diagnosed samples. The real-time PCR was the most sensitive (100 %) one among the methods used in diagnosis of AK. The 44 (19.0 %) out of 231 corneal scrapings, 4/4 (100 %) contact lens solution and 11/22 (50 %) of domestic tap water samples were found to be positive by real-time PCR for Acanthamoeba. A. griffini (T3), A. castellanii (T4) and A. jacobsi (T15) genotypes were obtained from corneal scrapings, contact lens solutions and domestic tap water samples taken from the patient's homes diagnosed with AK. The isolation of Acanthamoeba containing 6/22 (27.3 %) A. griffini (T3), 14/22 (63.6 %) A. castellanii (T4) and 2/22 (9.1 %) A. jacobsi (T15) from the domestic tap water outlets of 22 of 44 (50 %) of patient's homes revealed that is a significant source of these organisms. A. griffini (T3) and A. jacobsi (T15) genotypes have not been determined from AK cases in Turkey previously. Thus, we conclude that Acanthamoeba keratitis is associated with exposition of patients who has ocular trauma or ocular surface disease to domestic tap water in endemic or potentially endemic countries.

  7. Non-contact measurement of partial gas pressure and distribution of elemental composition using energy-resolved neutron imaging

    Directory of Open Access Journals (Sweden)

    A. S. Tremsin

    2017-01-01

    Full Text Available Neutron resonance absorption imaging is a non-destructive technique that can characterize the elemental composition of a sample by measuring nuclear resonances in the spectrum of a transmitted beam. Recent developments in pixelated time-of-flight imaging detectors coupled with pulsed neutron sources pose new opportunities for energy-resolved imaging. In this paper we demonstrate non-contact measurements of the partial pressure of xenon and krypton gases encapsulated in a steel pipe while simultaneously passing the neutron beam through high-Z materials. The configuration was chosen as a proof of principle demonstration of the potential to make non-destructive measurement of gas composition in nuclear fuel rods. The pressure measured from neutron transmission spectra (∼739 ± 98 kPa and ∼751 ± 154 kPa for two Xe resonances is in relatively good agreement with the pressure value of ∼758 ± 21 kPa measured by a pressure gauge. This type of imaging has been performed previously for solids with a spatial resolution of ∼ 100 μm. In the present study it is demonstrated that the high penetration capability of epithermal neutrons enables quantitative mapping of gases encapsulate within high-Z materials such as steel, tungsten, urania and others. This technique may be beneficial for the non-destructive testing of bulk composition of objects (such as spent nuclear fuel assemblies and others containing various elements opaque to other more conventional imaging techniques. The ability to image the gaseous substances concealed within solid materials also allows non-destructive leak testing of various containers and ultimately measurement of gas partial pressures with sub-mm spatial resolution.

  8. Two-dimensional motion analysis of dynamic knee valgus identifies female high school athletes at risk of non-contact anterior cruciate ligament injury.

    Science.gov (United States)

    Numata, Hitoaki; Nakase, Junsuke; Kitaoka, Katsuhiko; Shima, Yosuke; Oshima, Takeshi; Takata, Yasushi; Shimozaki, Kengo; Tsuchiya, Hiroyuki

    2018-02-01

    Female athletes are at greater risk of non-contact ACL injury. Three-dimensional kinematic analyses have shown that at-risk female athletes have a greater knee valgus angle during drop jumping. The purpose of this study was to evaluate the relationship between knee valgus angle and non-contact ACL injury in young female athletes using coronal-plane two-dimensional (2D) kinematic analyses of single-leg landing. Two hundred ninety-one female high school athletes newly enrolled in basketball and handball clubs were assessed. Dynamic knee valgus was analysed during single-leg drop jumps using 2D coronal images at hallux-ground contact and at maximal knee valgus. All subjects were followed up for 3 years for ACL injury. Twenty-eight (9.6%) of 291 athletes had ACL rupture, including 27 non-contact ACL injuries. The injured group of 27 knees with non-contact ACL injury was compared with a control group of 27 randomly selected uninjured knees. The relationship between initial 2D movement analysis results and subsequent ACL injury was investigated. Dynamic knee valgus was significantly greater in the injured group compared to the control group at hallux-ground contact (2.1 ± 2.4 vs. 0.4 ± 2.2 cm, P = 0.006) and at maximal knee valgus (8.3 ± 4.3 vs. 5.1 ± 4.1 cm, P = 0.007). The results of this study confirm that dynamic knee valgus is a potential risk factor for non-contact ACL injury in female high school athletes. Fully understanding the risk factors that increase dynamic knee valgus will help in designing more appropriate training and interventional strategies to prevent injuries in at-risk athletes. Prognostic studies, Level II.

  9. Piezoelectric Motors, an Overview

    Directory of Open Access Journals (Sweden)

    Karl Spanner

    2016-02-01

    Full Text Available Piezoelectric motors are used in many industrial and commercial applications. Various piezoelectric motors are available in the market. All of the piezoelectric motors use the inverse piezoelectric effect, where microscopically small oscillatory motions are converted into continuous or stepping rotary or linear motions. Methods of obtaining long moving distance have various drive and functional principles that make these motors categorized into three groups: resonance-drive (piezoelectric ultrasonic motors, inertia-drive, and piezo-walk-drive. In this review, a comprehensive summary of piezoelectric motors, with their classification from initial idea to recent progress, is presented. This review also includes some of the industrial and commercial applications of piezoelectric motors that are presently available in the market as actuators.

  10. Transmission Geometry Laser Ablation into a Non-Contact Liquid Vortex Capture Probe for Mass Spectrometry Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ovchinnikova, Olga S [ORNL; Bhandari, Deepak [ORNL; Lorenz, Matthias [ORNL; Van Berkel, Gary J [ORNL

    2014-01-01

    RATIONALE: Capture of material from a laser ablation plume into a continuous flow stream of solvent provides the means for uninterrupted sampling, transport and ionization of collected material for coupling with mass spectral analysis. Reported here is the use of vertically aligned transmission geometry laser ablation in combination with a new non-contact liquid vortex capture probe coupled with electrospray ionization for spot sampling and chemical imaging with mass spectrometry. Methods: A vertically aligned continuous flow liquid vortex capture probe was positioned directly underneath a sample surface in a transmission geometry laser ablation (355 nm, 10 Hz, 7 ns pulse width) setup to capture into solution the ablated material. The outlet of the vortex probe was coupled to the Turbo V ion source of an AB SCIEX TripleTOF 5600+ mass spectrometer. System operation and performance metrics were tested using inked patterns and thin tissue sections. Glass slides and slides designed especially for laser capture microdissection, viz., DIRECTOR slides and PEN 1.0 (polyethylene naphthalate) membrane slides, were used as sample substrates. Results: The estimated capture efficiency of laser ablated material was 24%, which was enabled by the use of a probe with large liquid surface area (~ 2.8 mm2) and with gravity to help direct ablated material vertically down towards the probe. The swirling vortex action of the liquid surface potentially enhanced capture and dissolution of not only particulates, but also gaseous products of the laser ablation. The use of DIRECTOR slides and PEN 1.0 (polyethylene naphthalate) membrane slides as sample substrates enabled effective ablation of a wide range of sample types (basic blue 7, polypropylene glycol, insulin and cyctochrome c) without photodamage using a UV laser. Imaging resolution of about 6 m was demonstrated for stamped ink on DIRECTOR slides based on the ability to distinguish features present both in the optical and in the

  11. Prevalence of non-contact and contact childhood sexual abuse: An Internet-based sample of men who have sex with men in China.

    Directory of Open Access Journals (Sweden)

    Wenjian Xu

    Full Text Available The prevalence of childhood sexual abuse (CSA is high among Western men who have sex with men (MSM, and CSA is associated with certain socio-demographic variables and with human immunodeficiency virus (HIV status. Little is known about CSA among Chinese MSM; therefore, we explored the prevalence and frequency of non-contact (e.g., sexual invitations, exhibitionism and contact (e.g., intercourse, genital contact forms of CSA in an Internet-based sample of MSM in China. We also examined the associations between the participants' socio-demographic characteristics and HIV status, and their histories of CSA.We surveyed MSM from 30 Chinese provinces in 2014-2015; 1,030 (mean age = 25.15 years, SD = 6.32 and 1,020 (mean age = 25.05 years, SD = 5.95 respondents were eligible for inclusion in the non-contact and contact CSA groups, respectively.Prevalence of non-contact and contact CSA was 36.2% and 29.8%, respectively; 20.4% and 15.0% had experienced non-contact and contact CSA ≥ 3 times, respectively. Most respondents were young adults, well educated, single, had never "come out," and self-identified as gay or bisexual men. Univariate analyses showed that respondents who had experienced contact CSA were more likely to be HIV-positive than those who had never experienced contact CSA. Multivariate analyses showed that non-contact CSA was associated with less education, being in a relationship with a woman or a man, and having "come out." Contact CSA was associated with less education, higher income, and being in a relationship with a man. Respondents who had experienced non-contact CSA ≥ 3 times were more likely to be less educated, "out," and to be in a relationship with a woman or a man. Respondents who had experienced contact CSA ≥ 3 times were more likely to be less educated and to be in a relationship with a man.It is necessary to pay closer attention to CSA among MSM and other sexual minorities in China.

  12. Stepping Motor - Hydraulic Motor Servo Drives for an NC Milling ...

    African Journals Online (AJOL)

    In this paper the retrofit design of the control system of an NC milling machine with a stepping motor and stepping motor - actuated hydraulic motor servo mechanism on the machines X-axis is described. The servo designed in the course of this study was tested practically and shown to be linear - the velocity following errors ...

  13. Characterization of a time-resolved non-contact scanning diffuse optical imaging system exploiting fast-gated single-photon avalanche diode detection

    Energy Technology Data Exchange (ETDEWEB)

    Di Sieno, Laura, E-mail: laura.disieno@polimi.it; Dalla Mora, Alberto; Contini, Davide [Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Wabnitz, Heidrun; Macdonald, Rainer [Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin (Germany); Pifferi, Antonio [Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Mazurenka, Mikhail [Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin (Germany); Hannoversches Zentrum für Optische Technologien, Nienburger Str. 17, 30167 Hannover (Germany); Hoshi, Yoko [Department of Biomedical Optics, Medical Photonics Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Boso, Gianluca; Tosi, Alberto [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Becker, Wolfgang [Becker and Hickl GmbH, Nahmitzer Damm 30, 12277 Berlin (Germany); Martelli, Fabrizio [Dipartimento di Fisica e Astronomia dell’Università degli Studi di Firenze, Via G. Sansone 1, Sesto Fiorentino, Firenze 50019 (Italy)

    2016-03-15

    We present a system for non-contact time-resolved diffuse reflectance imaging, based on small source-detector distance and high dynamic range measurements utilizing a fast-gated single-photon avalanche diode. The system is suitable for imaging of diffusive media without any contact with the sample and with a spatial resolution of about 1 cm at 1 cm depth. In order to objectively assess its performances, we adopted two standardized protocols developed for time-domain brain imagers. The related tests included the recording of the instrument response function of the setup and the responsivity of its detection system. Moreover, by using liquid turbid phantoms with absorbing inclusions, depth-dependent contrast and contrast-to-noise ratio as well as lateral spatial resolution were measured. To illustrate the potentialities of the novel approach, the characteristics of the non-contact system are discussed and compared to those of a fiber-based brain imager.

  14. Can two-dimensional video analysis during single-leg drop vertical jumps help identify non-contact knee injury risk? A one-year prospective study.

    Science.gov (United States)

    Dingenen, Bart; Malfait, Bart; Nijs, Stefaan; Peers, Koen H E; Vereecken, Styn; Verschueren, Sabine M P; Staes, Filip F

    2015-10-01

    Previous studies showed that the amount of hip flexion and the combination of knee valgus and lateral trunk motion, measured with two-dimensional video analysis, were related to three-dimensional measured knee joint moments during single-leg drop vertical jumps, but it remains unclear whether these measurements can be used to identify non-contact knee injury risk. Fifty injury-free female athletes participated in the study. Two-dimensional video analysis was used to measure hip flexion, knee valgus and lateral trunk motion angles during single-leg drop vertical jumps. Time loss non-contact knee injuries were registered during a one-year follow-up. Independent t-tests and receiver operating characteristic analysis were used to analyze the predictive ability of the two-dimensional angles. Seven participants sustained a time loss non-contact knee injury. Hip flexion was not significantly different between groups (P>.05). The combination of knee valgus and lateral trunk motion was significantly smaller in the injured (P=.036) and non-injured legs (P=.009) of the future injured group compared with the respective matched leg of the non-injured group. The receiver operating characteristic analysis showed a significant discriminative accuracy between groups for the combination of knee valgus and lateral trunk motion of the uninjured leg of the future injured group with the matched leg of the non-injured group (area under curve=0.803; P=.012). The measurement of a combination of increased knee valgus and ipsilateral trunk motion during the single-leg drop vertical jump with two-dimensional video analysis can be used to help identify female athletes with increased non-contact knee injury risk. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Non-linear stimulus-response behavior of the human stance control system is predicted by optimization of a system with sensory and motor noise.

    Science.gov (United States)

    van der Kooij, Herman; Peterka, Robert J

    2011-06-01

    We developed a theory of human stance control that predicted (1) how subjects re-weight their utilization of proprioceptive and graviceptive orientation information in experiments where eyes closed stance was perturbed by surface-tilt stimuli with different amplitudes, (2) the experimentally observed increase in body sway variability (i.e. the "remnant" body sway that could not be attributed to the stimulus) with increasing surface-tilt amplitude, (3) neural controller feedback gains that determine the amount of corrective torque generated in relation to sensory cues signaling body orientation, and (4) the magnitude and structure of spontaneous body sway. Responses to surface-tilt perturbations with different amplitudes were interpreted using a feedback control model to determine control parameters and changes in these parameters with stimulus amplitude. Different combinations of internal sensory and/or motor noise sources were added to the model to identify the properties of noise sources that were able to account for the experimental remnant sway characteristics. Various behavioral criteria were investigated to determine if optimization of these criteria could predict the identified model parameters and amplitude-dependent parameter changes. Robust findings were that remnant sway characteristics were best predicted by models that included both sensory and motor noise, the graviceptive noise magnitude was about ten times larger than the proprioceptive noise, and noise sources with signal-dependent properties provided better explanations of remnant sway. Overall results indicate that humans dynamically weight sensory system contributions to stance control and tune their corrective responses to minimize the energetic effects of sensory noise and external stimuli.

  16. PREFACE: NC-AFM 2005: Proceedings of the 8th International Conference on Non-Contact Atomic Force Microscopy

    Science.gov (United States)

    Reichling, M.; Mikosch, W.

    2006-04-01

    The 8th International Conference on Non-Contact Atomic Force Microscopy, held in Bad Essen, Germany, from 15 18th August 2005, attracted a record breaking number of participants presenting excellent contributions from a variety of scientific fields. This clearly demonstrated the high level of activity and innovation present in the community of NC-AFM researchers and the continuous growth of the field. The strongest ever participation of companies for a NC-AFM meeting is a sign for the emergence of new markets for the growing NC-AFM community; and the high standard of the products presented at the exhibition, many of them brand-new developments, reflected the unbroken progress in technology. The development of novel technologies and the sophistication of known techniques in research laboratories and their subsequent commercialization is still a major driving force for progress in this area of nanoscience. The conference was a perfect demonstration of how progress in the development of enabling technologies can readily be transcribed into basic research yielding fundamental insight with an impact across disciplines. The NC-AFM 2005 scientific programme was based on five cornerstones, each representing an area of vivid research and scientific progress. Atomic resolution imaging on oxide surfaces, which has long been a vision for the catalysis community, appears to be routine in several laboratories and after a period of demonstrative experiments NC-AFM now makes unique contributions to the understanding of processes in surface chemistry. These capabilities also open up new routes for the analysis of clusters and molecules deposited on dielectric surfaces where resolution limits are pushed towards the single atom level. Atomic precision manipulation with the dynamic AFM left the cradle of its infancy and flourishes in the family of bottom-up fabrication nanotechnologies. The systematic development of established and the introduction of new concepts of contrast

  17. Prevention of non-contact anterior cruciate ligament injuries in soccer players. Part 1: Mechanisms of injury and underlying risk factors.

    Science.gov (United States)

    Alentorn-Geli, Eduard; Myer, Gregory D; Silvers, Holly J; Samitier, Gonzalo; Romero, Daniel; Lázaro-Haro, Cristina; Cugat, Ramón

    2009-07-01

    Soccer is the most commonly played sport in the world, with an estimated 265 million active soccer players by 2006. Inherent to this sport is the higher risk of injury to the anterior cruciate ligament (ACL) relative to other sports. ACL injury causes the most time lost from competition in soccer which has influenced a strong research focus to determine the risk factors for injury. This research emphasis has afforded a rapid influx of literature defining potential modifiable and non-modifiable risk factors that increase the risk of injury. The purpose of the current review is to sequence the most recent literature that reports potential mechanisms and risk factors for non-contact ACL injury in soccer players. Most ACL tears in soccer players are non-contact in nature. Common playing situations precluding a non-contact ACL injury include: change of direction or cutting maneuvers combined with deceleration, landing from a jump in or near full extension, and pivoting with knee near full extension and a planted foot. The most common non-contact ACL injury mechanism include a deceleration task with high knee internal extension torque (with or without perturbation) combined with dynamic valgus rotation with the body weight shifted over the injured leg and the plantar surface of the foot fixed flat on the playing surface. Potential extrinsic non-contact ACL injury risk factors include: dry weather and surface, and artificial surface instead of natural grass. Commonly purported intrinsic risk factors include: generalized and specific knee joint laxity, small and narrow intercondylar notch width (ratio of notch width to the diameter and cross sectional area of the ACL), pre-ovulatory phase of menstrual cycle in females not using oral contraceptives, decreased relative (to quadriceps) hamstring strength and recruitment, muscular fatigue by altering neuromuscular control, decreased "core" strength and proprioception, low trunk, hip, and knee flexion angles, and high

  18. Precision magnetic suspension linear bearing

    Science.gov (United States)

    Trumper, David L.; Queen, Michael A.

    1992-01-01

    We have shown the design and analyzed the electromechanics of a linear motor suitable for independently controlling two suspension degrees of freedom. This motor, at least on paper, meets the requirements for driving an X-Y stage of 10 Kg mass with about 4 m/sq sec acceleration, with travel of several hundred millimeters in X and Y, and with reasonable power dissipation. A conceptual design for such a stage is presented. The theoretical feasibility of linear and planar bearings using single or multiple magnetic suspension linear motors is demonstrated.

  19. Nonlinear dynamics and control strategies: On a energy harvester vibrating system with a linear form to non-ideal motor torquet

    Directory of Open Access Journals (Sweden)

    de Pontes B. R.

    2012-07-01

    Full Text Available In this paper, we deal with the research of a vibrating model of an energy harvester device, including the nonlinearities in the model of the piezoelectric coupling and the non-ideal excitation. We show, using numerical simulations, in the analysis of the dynamic responses, that the harvested power is influenced by non-linear vibrations of the structure. Chaotic behavior was also observed, causing of the loss of energy throughout the simulation time. Using a perturbation technique, we find an approximate analytical solution for the non-ideal system. Then, we apply both two control techniques, to keep the considered system, into a stable condition. Both the State Dependent Ricatti Equation (SDRE control as the feedback control by changing the energy of the oscillator, were efficient in controlling of the considered non-ideal system.

  20. Non-Contact Sensor for Long-Term Continuous Vital Signs Monitoring: A Review on Intelligent Phased-Array Doppler Sensor Design.

    Science.gov (United States)

    Hall, Travis; Lie, Donald Y C; Nguyen, Tam Q; Mayeda, Jill C; Lie, Paul E; Lopez, Jerry; Banister, Ron E

    2017-11-15

    It has been the dream of many scientists and engineers to realize a non-contact remote sensing system that can perform continuous, accurate and long-term monitoring of human vital signs as we have seen in many Sci-Fi movies. Having an intelligible sensor system that can measure and record key vital signs (such as heart rates and respiration rates) remotely and continuously without touching the patients, for example, can be an invaluable tool for physicians who need to make rapid life-and-death decisions. Such a sensor system can also effectively help physicians and patients making better informed decisions when patients' long-term vital signs data is available. Therefore, there has been a lot of research activities on developing a non-contact sensor system that can monitor a patient's vital signs and quickly transmit the information to healthcare professionals. Doppler-based radio-frequency (RF) non-contact vital signs (NCVS) monitoring system are particularly attractive for long term vital signs monitoring because there are no wires, electrodes, wearable devices, nor any contact-based sensors involved so the subjects may not be even aware of the ubiquitous monitoring. In this paper, we will provide a brief review on some latest development on NCVS sensors and compare them against a few novel and intelligent phased-array Doppler-based RF NCVS biosensors we have built in our labs. Some of our NCVS sensor tests were performed within a clutter-free anechoic chamber to mitigate the environmental clutters, while most tests were conducted within the typical Herman-Miller type office cubicle setting to mimic a more practical monitoring environment. Additionally, we will show the measurement data to demonstrate the feasibility of long-term NCVS monitoring. The measured data strongly suggests that our latest phased array NCVS system should be able to perform long-term vital signs monitoring intelligently and robustly, especially for situations where the subject is sleeping

  1. The in vitro and in vivo validation of a mobile non-contact camera-based digital imaging system for tooth colour measurement.

    Science.gov (United States)

    Smith, Richard N; Collins, Luisa Z; Naeeni, Mojgan; Joiner, Andrew; Philpotts, Carole J; Hopkinson, Ian; Jones, Clare; Lath, Darren L; Coxon, Thomas; Hibbard, James; Brook, Alan H

    2008-01-01

    To assess the reproducibility of a mobile non-contact camera-based digital imaging system (DIS) for measuring tooth colour under in vitro and in vivo conditions. One in vitro and two in vivo studies were performed using a mobile non-contact camera-based digital imaging system. In vitro study: two operators used the DIS to image 10 dry tooth specimens in a randomised order on three occasions. In vivo study 1:25 subjects with two natural, normally aligned, upper central incisors had their teeth imaged using the DIS on four consecutive days by one operator to measure day-to-day variability. On one of the four test days, duplicate images were collected by three different operators to measure inter- and intra-operator variability. In vivo study 2:11 subjects with two natural, normally aligned, upper central incisors had their teeth imaged using the DIS twice daily over three days within the same week to assess day-to-day variability. Three operators collected images from subjects in a randomised order to measure inter- and intra-operator variability. Subject-to-subject variability was the largest source of variation within the data. Pairwise correlations and concordance coefficients were > 0.7 for each operator, demonstrating good precision and excellent operator agreement in each of the studies. Intraclass correlation coefficients (ICCs) for each operator indicate that day-to-day reliability was good to excellent, where all ICC's where > 0.75 for each operator. The mobile non-contact camera-based digital imaging system was shown to be a reproducible means of measuring tooth colour in both in vitro and in vivo experiments.

  2. Robust, accurate, and non-contacting vibration measurement systems: Summary of comparison measurements of the robust laser interferometer and typical accelerometer systems. Volume 1

    International Nuclear Information System (INIS)

    Goodenow, T.C.; Shipman, R.L.; Holland, H.M.

    1995-06-01

    Epoch Engineering, Incorporated (EEI) has completed a series of vibration measurements comparing their newly-developed Robust Laser Interferometer (RLI) with accelerometer-based instrumentation systems. EEI has successfully demonstrated, on several pieces of commonplace machinery, that non-contact, line-of-sight measurements are practical and yield results equal to or, in some cases, better than customary field implementations of accelerometers. The demonstration included analysis and comparison of such phenomena as nonlinearity, transverse sensitivity, harmonics, and signal-to-noise ratio. Fast Fourier Transformations were performed on the accelerometer and the laser system outputs to provide a comparison basis. The RLI was demonstrated, within the limits of the task, to be a viable, line-of-sight, non-contact alternative to accelerometer systems. Several different kinds of machinery were instrumented and compared, including a small pump, a gear-driven cement mixer, a rotor kit, and two small fans. Known machinery vibration sources were verified and RLI system output file formats were verified to be compatible with commercial computer programs used for vibration monitoring and trend analysis. The RLI was also observed to be less subject to electromagnetic interference (EMI) and more capable at very low frequencies

  3. Development and test of model apparatus of non-contact spin processor for photo mask production applying radial-type superconducting magnetic bearing

    International Nuclear Information System (INIS)

    Saito, Kimiyo; Fukui, Satoshi; Maezawa, Masaru; Ogawa, Jun; Oka, Tetsuo; Sato, Takao

    2013-01-01

    Highlights: ► We develop test spinner for non-contact spinning process in photo mask production. ► This test spinner shows improved spinning ability compared with our previous one. ► Large vertical movement of turn table still occurs during acceleration. ► Method to control vertical movement of turn table should be developed in next step. -- Abstract: In semiconductor devices, miniaturization of circuit patterning on wafers is required for higher integrations of circuit elements. Therefore, very high tolerance and quality are also required for patterning of microstructures of photo masks. The deposition of particulate dusts generated from mechanical bearings of the spin processor in the patterns of the photo mask is one of main causes of the deterioration of pattern preciseness. In our R and D, application of magnetic bearing utilizing bulk high temperature superconductors to the spin processors has been proposed. In this study, we develop a test spinner for the non-contact spinning process in the photo mask production system. The rotation test by using this test spinner shows that this test spinner accomplishes the improvement of the spinning ability compared with the test spinner developed in our previous study. This paper describes the rotation test results of the new test spinner applying the magnetic bearing with bulk high temperature superconductors

  4. Development of a novel non-contact inspection technique to detect micro cracks under the surface of a glass substrate by thermal stress-induced light scattering method

    Science.gov (United States)

    Sakata, Yoshitaro; Terasaki, Nao; Nonaka, Kazuhiro

    2017-05-01

    Fine polishing techniques, such as a chemical mechanical polishing treatment, are important techniques in glass substrate manufacturing. However, these techniques may cause micro cracks under the surface of glass substrates because they used mechanical friction. A stress-induced light scattering method (SILSM), which was combined with light scattering method and mechanical stress effects, was proposed for inspecting surfaces to detect polishing-induced micro cracks. However, in the conventional SILSM, samples need to be loaded with physical contact, and the loading point is invisible in transparent materials. Here, we introduced a novel non-contact SILSM using a heating device. A glass substrate was heated first, and then the light scattering intensity of micro cracks was detected by a cooled charge-couple device camera during the natural cooling process. Results clearly showed during the decreasing surface temperature of a glass substrate, appropriate thermal stress is generated for detecting micro cracks by using the SILSM and light scattering intensity from micro cracks changes. We confirmed that non-contact thermal SILSM (T-SILSM) can detect micro cracks under the surface of transparent materials.

  5. Robust, accurate, and non-contacting vibration measurement systems: Supplemental appendices presenting comparison measurements of the robust laser interferometer and typical accelerometer systems. Volume 2

    International Nuclear Information System (INIS)

    Goodenow, T.C.; Shipman, R.L.; Holland, H.M.

    1995-06-01

    Epoch Engineering, Incorporated (EEI) has completed a series of vibration measurements comparing their newly-developed Robust Laser Interferometer (RLI) with accelerometer-based instrumentation systems. EEI has successfully demonstrated, on several pieces of commonplace machinery, that non-contact, line-of-sight measurements are practical and yield results equal to or, in some cases, better than customary field implementations of accelerometers. The demonstration included analysis and comparison of such phenomena as nonlinearity, transverse sensitivity, harmonics, and signal-to-noise ratio. Fast Fourier Transformations were performed on the accelerometer and the laser system outputs to provide a comparison basis. The RLI was demonstrated, within the limits o the task, to be a viable, line-of-sight, non-contact alternative to accelerometer systems. Several different kinds of machinery were instrumented and. compared, including a small pump, a gear-driven cement mixer, a rotor kit, and two small fans. Known machinery vibration sources were verified and RLI system output file formats were verified to be compatible with commercial computer programs used for vibration monitoring and trend analysis. The RLI was also observed to be less subject to electromagnetic interference (EMI) and more capable at very low frequencies. This document, Volume 2, provides the appendices to this report

  6. Detailed rock failure susceptibility mapping in steep rocky coasts by means of non-contact geostructural surveys: the case study of the Tigullio Gulf (Eastern Liguria, Northern Italy

    Directory of Open Access Journals (Sweden)

    P. De Vita

    2012-04-01

    Full Text Available In this study, an engineering geological analysis for the assessment of the rock failure susceptibility of a high, steep, rocky coast was developed by means of non-contact geostructural surveys. The methodology was applied to a 6-km coastal cliff located in the Gulf of Tigullio (Northern Tyrrhenian Sea between Rapallo and Chiavari.

    The method is based on the geostructural characterisation of outcropping rock masses through meso- and macroscale stereoscopic analyses of digital photos that were taken continuously from a known distance from the coastline. The results of the method were verified through direct surveys of accessible sample areas. The rock failure susceptibility of the coastal sector was assessed by analysing the fundamental rock slope mechanisms of instability and the results were implemented into a Geographic Information System (GIS.

    The proposed method is useful for rock failure susceptibility assessments in high, steep, rocky coastal areas, where accessibility is limited due to cliffs or steep slopes. Moreover, the method can be applied to private properties or any other area where a complete and systematic analysis of rock mass structural features cannot be achieved.

    Compared to direct surveys and to other non-contact methods based on digital terrestrial photogrammetry, the proposed procedure provided good quality data of the structural features of the rock mass at a low cost. Therefore, the method could be applied to similar coastal areas with a high risk of rock failure occurrence.

  7. A quantitative and non-contact technique to characterise microstructural variations of skin tissues during photo-damaging process based on Mueller matrix polarimetry.

    Science.gov (United States)

    Dong, Yang; He, Honghui; Sheng, Wei; Wu, Jian; Ma, Hui

    2017-10-31

    Skin tissue consists of collagen and elastic fibres, which are highly susceptible to damage when exposed to ultraviolet radiation (UVR), leading to skin aging and cancer. However, a lack of non-invasive detection methods makes determining the degree of UVR damage to skin in real time difficult. As one of the fundamental features of light, polarization can be used to develop imaging techniques capable of providing structural information about tissues. In particular, Mueller matrix polarimetry is suitable for detecting changes in collagen and elastic fibres. Here, we demonstrate a novel, quantitative, non-contact and in situ technique based on Mueller matrix polarimetry for monitoring the microstructural changes of skin tissues during UVR-induced photo-damaging. We measured the Mueller matrices of nude mouse skin samples, then analysed the transformed parameters to characterise microstructural changes during the skin photo-damaging and self-repairing processes. Comparisons between samples with and without the application of a sunscreen showed that the Mueller matrix-derived parameters are potential indicators for fibrous microstructure in skin tissues. Histological examination and Monte Carlo simulations confirmed the relationship between the Mueller matrix parameters and changes to fibrous structures. This technique paves the way for non-contact evaluation of skin structure in cosmetics and dermatological health.

  8. Er:YAG and CTH:YAG laser radiation: contact versus non-contact enamel ablation and sonic-activated bulk composite placement

    Science.gov (United States)

    Buckova, M.; Kasparova, M.; Dostalova, T.; Jelinkova, H.; Sulc, J.; Nemec, M.; Fibrich, M.; Bradna, P.; Miyagi, M.

    2013-05-01

    Laser radiation can be used for effective caries removal and cavity preparation without significant thermal effects, collateral damage of tooth structure, or patient discomfort. The aim of this study was to compare the quality of tissue after contact or non-contact Er:YAG and CTH:YAG laser radiation ablation. The second goal was to increase the sealing ability of hard dental tissues using sonic-activated bulk filling material with change in viscosity during processing. The artificial caries was prepared in intact teeth to simulate a demineralized surface and then the Er:YAG or CTH:YAG laser radiation was applied. The enamel artificial caries was gently removed by the laser radiation and sonic-activated composite fillings were inserted. A stereomicroscope and then a scanning electron microscope were used to evaluate the enamel surface. Er:YAG contact mode ablation in enamel was quick and precise; the cavity was smooth with a keyhole shaped prism and rod relief arrangement without a smear layer. The sonic-activated filling material was consistently regularly distributed; no cracks or microleakage in the enamel were observed. CTH:YAG irradiation was able to clean but not ablate the enamel surface; in contact and also in non-contact mode there was evidence of melting and fusing of the enamel.

  9. Preconception Micronutrient Supplementation with Iron and Folic Acid Compared with Folic Acid Alone Affects Linear Growth and Fine Motor Development at 2 Years of Age: A Randomized Controlled Trial in Vietnam.

    Science.gov (United States)

    Nguyen, Phuong H; Gonzalez-Casanova, Ines; Young, Melissa F; Truong, Truong Viet; Hoang, Hue; Nguyen, Huong; Nguyen, Son; DiGirolamo, Ann M; Martorell, Reynaldo; Ramakrishnan, Usha

    2017-08-01

    Background: Maternal health and nutrition play a crucial role in early child growth and development. However, little is known about the benefits of preconception micronutrient interventions beyond the role of folic acid (FA) and neural tube defects. Objective: We evaluated the impact of weekly preconception multiple micronutrient (MM) or iron and folic acid (IFA) supplementation on child growth and development through the age of 2 y compared with FA alone. Methods: We followed 1599 offspring born to women who participated in a randomized controlled trial of preconception supplementation in Vietnam. Women received weekly supplements that contained either 2800 μg FA, 60 mg Fe and 2800 μg FA, or 15 MMs including IFA, from baseline until conception followed by daily prenatal IFA supplements until delivery. Child anthropometry was measured at birth and at 3, 6, 12, 18, and 24 mo. Child development was measured with the use of the Bayley Scales for Infant Development III at 24 mo. Results: The groups were similar for baseline maternal and offspring birth characteristics. At 24 mo of age, the offspring in the IFA group had significantly higher length-for-age z scores (LAZs) (0.14; 95% CI: 0.03, 0.26), reduced risk of being stunted (0.87; 95% CI: 0.76, 0.99), and smaller yearly decline in LAZs (0.10; 95% CI: 0.04, 0.15) than the offspring in the FA group. Similar trends were found for the offspring in the MM group compared with the FA group for LAZs (0.10; 95% CI: -0.02, 0.22) and the risk of being stunted (0.88; 95% CI: 0.77, 1.01). Offspring in the IFA group had improved motor development ( P = 0.03), especially fine motor development (0.41; 95% CI: 0.05, 0.77), at the age of 24 mo, but there were no differences for measures of cognition or language. Conclusions: Preconception supplementation with IFA improved linear growth and fine motor development at 2 y of age compared with FA. Future studies should examine whether these effects persist and improve child health and

  10. A non-contact, thermal noise based method for the calibration of lateral deflection sensitivity in atomic force microscopy

    International Nuclear Information System (INIS)

    Mullin, Nic; Hobbs, Jamie K.

    2014-01-01

    Calibration of lateral forces and displacements has been a long standing problem in lateral force microscopies. Recently, it was shown by Wagner et al. that the thermal noise spectrum of the first torsional mode may be used to calibrate the deflection sensitivity of the detector. This method is quick, non-destructive and may be performed in situ in air or liquid. Here we make a full quantitative comparison of the lateral inverse optical lever sensitivity obtained by the lateral thermal noise method and the shape independent method developed by Anderson et al. We find that the thermal method provides accurate results for a wide variety of rectangular cantilevers, provided that the geometry of the cantilever is suitable for torsional stiffness calibration by the torsional Sader method, in-plane bending of the cantilever may be eliminated or accounted for and that any scaling of the lateral deflection signal between the measurement of the lateral thermal noise and the measurement of the lateral deflection is eliminated or corrected for. We also demonstrate that the thermal method may be used to characterize the linearity of the detector signal as a function of position, and find a deviation of less than 8% for the instrument used

  11. Non-Contact Sensor for Long-Term Continuous Vital Signs Monitoring: A Review on Intelligent Phased-Array Doppler Sensor Design

    Directory of Open Access Journals (Sweden)

    Travis Hall

    2017-11-01

    Full Text Available It has been the dream of many scientists and engineers to realize a non-contact remote sensing system that can perform continuous, accurate and long-term monitoring of human vital signs as we have seen in many Sci-Fi movies. Having an intelligible sensor system that can measure and record key vital signs (such as heart rates and respiration rates remotely and continuously without touching the patients, for example, can be an invaluable tool for physicians who need to make rapid life-and-death decisions. Such a sensor system can also effectively help physicians and patients making better informed decisions when patients’ long-term vital signs data is available. Therefore, there has been a lot of research activities on developing a non-contact sensor system that can monitor a patient’s vital signs and quickly transmit the information to healthcare professionals. Doppler-based radio-frequency (RF non-contact vital signs (NCVS monitoring system are particularly attractive for long term vital signs monitoring because there are no wires, electrodes, wearable devices, nor any contact-based sensors involved so the subjects may not be even aware of the ubiquitous monitoring. In this paper, we will provide a brief review on some latest development on NCVS sensors and compare them against a few novel and intelligent phased-array Doppler-based RF NCVS biosensors we have built in our labs. Some of our NCVS sensor tests were performed within a clutter-free anechoic chamber to mitigate the environmental clutters, while most tests were conducted within the typical Herman-Miller type office cubicle setting to mimic a more practical monitoring environment. Additionally, we will show the measurement data to demonstrate the feasibility of long-term NCVS monitoring. The measured data strongly suggests that our latest phased array NCVS system should be able to perform long-term vital signs monitoring intelligently and robustly, especially for situations where the

  12. Design of a Bearingless Outer Rotor Induction Motor

    Directory of Open Access Journals (Sweden)

    Yuxin Sun

    2017-05-01

    Full Text Available A bearingless induction (BI motor with an outer rotor for flywheel energy storage systems is proposed due to the perceived advantages of simple rotor structure, non-contact support and high speed operation. Firstly, the configuration and operation principle of the proposed motor are described. Then several leading dimensional parameters are optimally calculated for achieving the maximum average values and the minimum ripples of torque output and suspension force. Finally, by using the finite element method, the characteristics and performance of the proposed machine are analyzed and verified.

  13. Linear Algebra and Linear Models

    Indian Academy of Sciences (India)

    Linear Algebra and Linear. Models. Kalyan Das. Linear Algebra and linear Models. (2nd Edn) by R P Bapat. Hindustan Book Agency, 1999 pp.xiii+180, Price: Rs.135/-. This monograph provides an introduction to the basic aspects of the theory oflinear estima- tion and that of testing linear hypotheses. The primary objective ...

  14. Control of non-conventional synchronous motors

    CERN Document Server

    Louis, Jean-Paul

    2013-01-01

    Classical synchronous motors are the most effective device to drive industrial production systems and robots with precision and rapidity. However, numerous applications require efficient controls in non-conventional situations. Firstly, this is the case with synchronous motors supplied by thyristor line-commutated inverters, or with synchronous motors with faults on one or several phases. Secondly, many drive systems use non-conventional motors such as polyphase (more than three phases) synchronous motors, synchronous motors with double excitation, permanent magnet linear synchronous motors,

  15. Light-driven molecular motors

    NARCIS (Netherlands)

    van Delden, RA; Feringa, BL; Kuzmany, H; Fink, J; Mehring, M; Roth, S

    2004-01-01

    Molecular motors can be defined as molecules that are able to convert any type of energy input (a fuel) into controlled motion. These systems can be categorized into linear and rotary motors, depending on the motion induced. This brief account will discuss the state of affairs of the research on

  16. Rapid, non-destructive and non-contact inspection of solid foods by means of photothermal radiometry; thermal effusivity and initial heating coefficient

    Science.gov (United States)

    Gijsbertsen, A.; Bicanic, D.; Gielen, J. L. W.; Chirtoc, M.

    2004-03-01

    CO 2-laser photothermal radiometry (PTR) was demonstrated to be suitable for the non-destructive and non-contact characterization (both optical and thermal) of solid phase agricultural commodities (fresh vegetables, fruits) and confectionery products (candy). Proper interpretation of PTR signals enable one to calculate two parameters, i.e. the well known thermal effusivity e ( e= λρc p, where λ and ρcp are the thermal conductivity and the volume specific heat, respectively) and a newly introduced physical quantity termed 'initial heating coefficient' chi ( χ= β/( ρcp), β is the absorption coefficient). Obtained values for e are in a good agreement with data reported in the literature. PTR enables one to rapidly determine e via a single measurement. As opposed to this, the knowledge of two out of three thermophysical parameters (thermal diffusivity, thermal conductivity and volume specific heat) is a condition sine qua non for determining effusivity in the conventional manner.

  17. Study on the Rotation Properties and the Design Issue of Non-Contact Rotating System Using HTS Bulks and Permanent Magnets

    Science.gov (United States)

    Okamura, R.; Kim, S. B.; Ozaki, Y.; Ueda, H.

    2017-07-01

    In previous study, non-contact rotating system consisting of the ring-shaped high temperature superconducting (HTS) bulks, ring-shaped permanent magnets (PMs) and stator coil was proposed. In this system, HTS bulks were magnetized by PMs and PMs were levitated with strong restoring force. In our previous study, we have constructed the rotating system with the ring-shaped HTS bulks with ID 20 mm, OD 60 mm, and 15-mm thickness. However, since these bulks costs too much, we switched to use HTS bulks with ID 20 mm, OD 60 mm, and 5-mm-thickness to miniaturize the system. However, this system have potential to fail the radial stability of rotating shaft. Therefore, we focused on the rotating and the radial restoring force in terms of the stability of the rotating shaft in the rotating system with 5-mm thickness HTS bulks.

  18. Preparation of n-type Bi{sub 2}Te{sub 3} thermoelectric materials by non-contact dispenser printing combined with selective laser melting

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Keping; Yan, Yonggao; Zhang, Jian; Mao, Yu; Xie, Hongyao; Zhang, Qingjie; Tang, Xinfeng [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, Hubei (China); Yang, Jihui [Department of Materials Science and Engineering, University of Washington, Seattle, WA (United States); Uher, Ctirad [Department of Physics, University of Michigan, Ann Arbor, MI (United States)

    2017-06-15

    The manufacturing cost has been a bottle neck for broader applications of thermoelectric (TE) modules. We have developed a rapid, facile, and low cost method that combines non-contact dispenser printing with selective laser melting (SLM) and we demonstrate it on n-type Bi{sub 2}Te{sub 3}-based materials. Using this approach, single phase n-type Bi{sub 2}Te{sub 2.7}Se{sub 0.3} thin layers with the Seebeck coefficient of -152 μV K{sup -1} at 300 K have been prepared. Assembling such thin layers on top of each other, the performance of thus prepared bulk sample is comparable to Bi{sub 2}Te{sub 3}-based materials fabricated by the conventional techniques. Dispenser printing combined with SLM is a promising manufacturing process for TE materials. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Pulse electrochemical machining on Invar alloy: Optical microscopic/SEM and non-contact 3D measurement study of surface analyses

    Science.gov (United States)

    Kim, S. H.; Choi, S. G.; Choi, W. K.; Yang, B. Y.; Lee, E. S.

    2014-09-01

    In this study, Invar alloy (Fe 63.5%, Ni 36.5%) was electrochemically polished by PECM (Pulse Electro Chemical Machining) in a mixture of NaCl, glycerin, and distilled water. A series of PECM experiments were carried out with different voltages and different electrode shapes, and then the surfaces of polished Invar alloy were investigated. The polished Invar alloy surfaces were investigated by optical microscope, scanning electron microscope (SEM), and non-contact 3D measurement (white light microscopes) and it was found that different applied voltages produced different surface characteristics on the Invar alloy surface because of the locally concentrated applied voltage on the Invar alloy surface. Moreover, we found that the shapes of electrode also have an effect on the surface characteristics on Invar alloy surface by influencing the applied voltage. These experimental findings provide fundamental knowledge for PECM of Invar alloy by surface analysis.

  20. The Effectiveness of Injury Prevention Programs to Modify Risk Factors for Non-Contact Anterior Cruciate Ligament and Hamstring Injuries in Uninjured Team Sports Athletes: A Systematic Review.

    Science.gov (United States)

    Monajati, Alireza; Larumbe-Zabala, Eneko; Goss-Sampson, Mark; Naclerio, Fernando

    2016-01-01

    Hamstring strain and anterior cruciate ligament injuries are, respectively, the most prevalent and serious non-contact occurring injuries in team sports. Specific biomechanical and neuromuscular variables have been used to estimate the risk of incurring a non-contact injury in athletes. The aim of this study was to systematically review the evidences for the effectiveness of injury prevention protocols to modify biomechanical and neuromuscular anterior cruciate and/or hamstring injuries associated risk factors in uninjured team sport athletes. PubMed, Science Direct, Web of Science, Cochrane Libraries, U.S. National Institutes of Health clinicaltrials.gov, Sport Discuss and Google Scholar databases were searched for relevant journal articles published until March 2015. A manual review of relevant articles, authors, and journals, including bibliographies was performed from identified articles. Nineteen studies were included in this review. Four assessment categories: i) landing, ii) side cutting, iii) stop-jump, and iv) muscle strength outcomes, were used to analyze the effectiveness of the preventive protocols. Eight studies using multifaceted interventions supported by video and/or technical feedback showed improvement in landing and/or stop-jump biomechanics, while no effects were observed on side-cutting maneuver. Additionally, multifaceted programs including hamstring eccentric exercises increased hamstring strength, hamstring to quadriceps functional ratio and/or promoted a shift of optimal knee flexion peak torque toward a more open angle position. Multifaceted programs, supported by proper video and/or technical feedback, including eccentric hamstring exercises would positively modify the biomechanical and or neuromuscular anterior cruciate and/or hamstring injury risk factors.

  1. The Effectiveness of Injury Prevention Programs to Modify Risk Factors for Non-Contact Anterior Cruciate Ligament and Hamstring Injuries in Uninjured Team Sports Athletes: A Systematic Review.

    Directory of Open Access Journals (Sweden)

    Alireza Monajati

    Full Text Available Hamstring strain and anterior cruciate ligament injuries are, respectively, the most prevalent and serious non-contact occurring injuries in team sports. Specific biomechanical and neuromuscular variables have been used to estimate the risk of incurring a non-contact injury in athletes.The aim of this study was to systematically review the evidences for the effectiveness of injury prevention protocols to modify biomechanical and neuromuscular anterior cruciate and/or hamstring injuries associated risk factors in uninjured team sport athletes.PubMed, Science Direct, Web of Science, Cochrane Libraries, U.S. National Institutes of Health clinicaltrials.gov, Sport Discuss and Google Scholar databases were searched for relevant journal articles published until March 2015. A manual review of relevant articles, authors, and journals, including bibliographies was performed from identified articles.Nineteen studies were included in this review. Four assessment categories: i landing, ii side cutting, iii stop-jump, and iv muscle strength outcomes, were used to analyze the effectiveness of the preventive protocols. Eight studies using multifaceted interventions supported by video and/or technical feedback showed improvement in landing and/or stop-jump biomechanics, while no effects were observed on side-cutting maneuver. Additionally, multifaceted programs including hamstring eccentric exercises increased hamstring strength, hamstring to quadriceps functional ratio and/or promoted a shift of optimal knee flexion peak torque toward a more open angle position.Multifaceted programs, supported by proper video and/or technical feedback, including eccentric hamstring exercises would positively modify the biomechanical and or neuromuscular anterior cruciate and/or hamstring injury risk factors.

  2. Non-contact full-field optical coherence tomography: a novel tool for in vivo imaging of the human cornea (Conference Presentation)

    Science.gov (United States)

    Mazlin, Viacheslav; Dalimier, Eugénie; Grieve, Katharine F.; Irsch, Kristina; Sahel, José-Alain; Fink, Mathias; Boccara, A. Claude

    2017-02-01

    According to the World Health Organization (WHO), corneal diseases alongside with cataract and retinal diseases are major causes of blindness worldwide. For the 95.5% of corneal blindness cases, prevention or rehabilitation could have been possible without negative consequences for vision, provided that disease is diagnosed early. However, diagnostics at the early stage requires cellular-level resolution, which is not achieved with routinely used Slit-lamp and OCT instruments. Confocal microscopy allows examination of the cornea at a resolution approaching histological detail, however requires contact with a patient's eye. The recently developed full-field OCT technique, in which 2D en face tangential optical slices are directly recorded on a camera, was successfully applied for ex vivo eye imaging. However, in vivo human eye imaging has not been demonstrated yet. Here we present a novel non-contact full-field OCT system, which is capable of imaging in air and, therefore, shows potential for in vivo cornea imaging in patients. The first cellular-level resolution ex vivo images of cornea, obtained in a completely non-contact way, were demonstrated. We were able to scan through the entire cornea (400 µm) and resolve epithelium, Bowman's layer, stroma and endothelium. FFOCT images of the human cornea in vivo were obtained for the first time. The epithelium structures and stromal keratocyte cells were distinguishable. Both ex vivo and in vivo images were acquired with a large (1.26 mm x 1.26 mm) field of view. Cellular details in obtained images make this device a promising candidate for realization of high-resolution in vivo cornea imaging.

  3. Linear step drive

    International Nuclear Information System (INIS)

    Haniger, L.; Elger, R.; Kocandrle, L.; Zdebor, J.

    1986-01-01

    A linear step drive is described developed in Czechoslovak-Soviet cooperation and intended for driving WWER-1000 control rods. The functional principle is explained of the motor and the mechanical and electrical parts of the drive, power control, and the indicator of position are described. The motor has latches situated in the reactor at a distance of 3 m from magnetic armatures, it has a low structural height above the reactor cover, which suggests its suitability for seismic localities. Its magnetic circuits use counterpoles; the mechanical shocks at the completion of each step are damped using special design features. The position indicator is of a special design and evaluates motor position within ±1% of total travel. A drive diagram and the flow chart of both the control electronics and the position indicator are presented. (author) 4 figs

  4. Linear algebra

    CERN Document Server

    Shilov, Georgi E

    1977-01-01

    Covers determinants, linear spaces, systems of linear equations, linear functions of a vector argument, coordinate transformations, the canonical form of the matrix of a linear operator, bilinear and quadratic forms, Euclidean spaces, unitary spaces, quadratic forms in Euclidean and unitary spaces, finite-dimensional space. Problems with hints and answers.

  5. Prevention of non-contact anterior cruciate ligament injuries in soccer players. Part 2: a review of prevention programs aimed to modify risk factors and to reduce injury rates.

    Science.gov (United States)

    Alentorn-Geli, Eduard; Myer, Gregory D; Silvers, Holly J; Samitier, Gonzalo; Romero, Daniel; Lázaro-Haro, Cristina; Cugat, Ramón

    2009-08-01

    Soccer is the most commonly played sport in the world, with an estimated 265 million active soccer players participating in the game as on 2006. Inherent to this sport is the higher risk of injury to the anterior cruciate ligament (ACL) relative to other sports. ACL injury causes a significant loss of time from competition in soccer, which has served as the strong impetus to conduct research that focuses to determine the risk factors for injury, and more importantly, to identify and teach techniques to reduce this injury in the sport. This research emphasis has afforded a rapid influx of literature aimed to report the effects of neuromuscular training on the risk factors and the incidence of non-contact ACL injury in high-risk soccer populations. The purpose of the current review is to sequence the most recent literature relating the effects of prevention programs that were developed to alter risk factors associated with non-contact ACL injuries and to reduce the rate of non-contact ACL injuries in soccer players. To date there is no standardized intervention program established for soccer to prevent non-contact ACL injuries. Multi-component programs show better results than single-component preventive programs to reduce the risk and incidence of non-contact ACL injuries in soccer players. Lower extremity plyometrics, dynamic balance and strength, stretching, body awareness and decision-making, and targeted core and trunk control appear to be successful training components to reduce non-contact ACL injury risk factors (decrease landing forces, decrease varus/valgus moments, and increase effective muscle activation) and prevent non-contact ACL injuries in soccer players, especially in female athletes. Pre-season injury prevention combined with an in-season maintenance program may be advocated to prevent injury. Compliance may in fact be the limiting factor to the overall success of ACL injury interventions targeted to soccer players regardless of gender. Thus

  6. Motor Neurons

    DEFF Research Database (Denmark)

    Hounsgaard, Jorn

    2017-01-01

    Motor neurons translate synaptic input from widely distributed premotor networks into patterns of action potentials that orchestrate motor unit force and motor behavior. Intercalated between the CNS and muscles, motor neurons add to and adjust the final motor command. The identity and functional...... properties of this facility in the path from synaptic sites to the motor axon is reviewed with emphasis on voltage sensitive ion channels and regulatory metabotropic transmitter pathways. The catalog of the intrinsic response properties, their underlying mechanisms, and regulation obtained from motoneurons...... in in vitro preparations is far from complete. Nevertheless, a foundation has been provided for pursuing functional significance of intrinsic response properties in motoneurons in vivo during motor behavior at levels from molecules to systems....

  7. A review of linear compressors for refrigeration

    OpenAIRE

    Liang, Kun

    2017-01-01

    Linear compressor has no crank mechanism compared with conventional reciprocating compressor. This allows higher efficiency, oil-free operation, lower cost and smaller size when linear compressors are used for vapour compression refrigeration (VCR) system. Typically, a linear compressor consists of a linear motor (connected to a piston) and suspension springs, operated at resonant frequency. This paper presents a review of linear compressors for refrigeration system. Different designs and mod...

  8. Self-calibrated non-contact fibre-optic Fabry–Perot interferometric vibration displacement sensor system using laser emission frequency modulated phase generated carrier demodulation scheme

    International Nuclear Information System (INIS)

    Jia, P G; Wang, D H

    2012-01-01

    In this paper, the principle of a self-calibrated non-contact fibre-optic Fabry–Perot interferometric vibration displacement sensor (FOFPIVDS) system is described and experimentally demonstrated. According to the principle, the Fabry–Perot cavity, constituted by placing the end face of a gradient-index lens in parallel with the measured vibration surface, is used to translate the vibration displacement of the measured vibration surface into phase shifts in the interference signal output from the FOFPIVDS, and the laser emission frequency modulated phase generated carrier (FMPGC) demodulation scheme based on the arctangent (Arctan) algorithm is adapted to demodulate the phase shifts. After eliminating the optical power modulation in the laser emission frequency modulation, the sensing model for the FOFPIVDS system using the FMPGC–Arctan demodulation scheme is established. On these bases, the FOFPIVDS is designed and fabricated, and the prototyping FOFPIVDS system is built and experimentally tested. The research results indicate that the fabricated FOFPIVDS system possesses the characteristics as follows: (1) the sensitivity is only determined by the laser wavelength and the vibration displacement measurement is self-calibrated, (2) the nonlinearity is 0.29% and (3) the resolution is less than 2.06 nm. (paper)

  9. Non-contact, non-destructive, quantitative probing of interfacial trap sites for charge carrier transport at semiconductor-insulator boundary

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Wookjin; Miyakai, Tomoyo; Sakurai, Tsuneaki; Saeki, Akinori [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan); Yokoyama, Masaaki [Kaneka Fundamental Technology Research Alliance Laboratories, Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan); Seki, Shu, E-mail: seki@chem.eng.osaka-u.ac.jp [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan); Kaneka Fundamental Technology Research Alliance Laboratories, Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan)

    2014-07-21

    The density of traps at semiconductor–insulator interfaces was successfully estimated using microwave dielectric loss spectroscopy with model thin-film organic field-effect transistors. The non-contact, non-destructive analysis technique is referred to as field-induced time-resolved microwave conductivity (FI-TRMC) at interfaces. Kinetic traces of FI-TRMC transients clearly distinguished the mobile charge carriers at the interfaces from the immobile charges trapped at defects, allowing both the mobility of charge carriers and the number density of trap sites to be determined at the semiconductor-insulator interfaces. The number density of defects at the interface between evaporated pentacene on a poly(methylmethacrylate) insulating layer was determined to be 10{sup 12 }cm{sup −2}, and the hole mobility was up to 6.5 cm{sup 2} V{sup −1} s{sup −1} after filling the defects with trapped carriers. The FI-TRMC at interfaces technique has the potential to provide rapid screening for the assessment of interfacial electronic states in a variety of semiconductor devices.

  10. Non-contact, non-destructive, quantitative probing of interfacial trap sites for charge carrier transport at semiconductor-insulator boundary

    Science.gov (United States)

    Choi, Wookjin; Miyakai, Tomoyo; Sakurai, Tsuneaki; Saeki, Akinori; Yokoyama, Masaaki; Seki, Shu

    2014-07-01

    The density of traps at semiconductor-insulator interfaces was successfully estimated using microwave dielectric loss spectroscopy with model thin-film organic field-effect transistors. The non-contact, non-destructive analysis technique is referred to as field-induced time-resolved microwave conductivity (FI-TRMC) at interfaces. Kinetic traces of FI-TRMC transients clearly distinguished the mobile charge carriers at the interfaces from the immobile charges trapped at defects, allowing both the mobility of charge carriers and the number density of trap sites to be determined at the semiconductor-insulator interfaces. The number density of defects at the interface between evaporated pentacene on a poly(methylmethacrylate) insulating layer was determined to be 1012 cm-2, and the hole mobility was up to 6.5 cm2 V-1 s-1 after filling the defects with trapped carriers. The FI-TRMC at interfaces technique has the potential to provide rapid screening for the assessment of interfacial electronic states in a variety of semiconductor devices.

  11. Quantitative assessment of hemodynamic and structural characteristics of in vivo brain tissue using total diffuse reflectance spectrum measured in a non-contact fashion.

    Science.gov (United States)

    Song, Yinchen; Garcia, Sarahy; Frometa, Yisel; Ramella-Roman, Jessica C; Soltani, Mohammad; Almadi, Mohamed; Riera, Jorge J; Lin, Wei-Chiang

    2017-01-01

    Here we present a new methodology that investigates the intrinsic structural and hemodynamic characteristics of in vivo brain tissue, in a non-contact fashion, and can be easily incorporated in an intra-operative environment. Within this methodology, relative total diffuse reflectance spectra (R TD (λ)) were acquired from targets using a hybrid spectroscopy imaging system. A spectral interpretation algorithm was subsequently applied to R TD (λ) to retrieve optical properties related to the compositional and structural characteristics of each target. Estimation errors of the proposed methodology were computationally evaluated using a Monte Carlo simulation model for photon migration under various conditions. It was discovered that this new methodology could handle moderate noise and achieve very high accuracy, but only if the refractive index of the target is known. The accuracy of the technique was also validated using a series of tissue phantom studies, and consistent and accurate estimates of μ s '(λ)/μ a (λ) were obtained from all the phantoms tested. Finally, a small-scale animal study was conducted to demonstrate the clinical utility of the reported method, wherein a forepaw stimulation model was utilized to induce transient hemodynamic responses in somatosensory cortices. With this approach, significant stimulation-related changes (p < 0.001) in cortical hemodynamic and structural characteristics were successfully measured.

  12. Non-contact electric potential measurements of electrode components in an operating polymer electrolyte fuel cell by near ambient pressure XPS.

    Science.gov (United States)

    Yu, Liwei; Takagi, Yasumasa; Nakamura, Takahiro; Sekizawa, Oki; Sakata, Tomohiro; Uruga, Tomoya; Tada, Mizuki; Iwasawa, Yasuhiro; Samjeské, Gabor; Yokoyama, Toshihiko

    2017-11-22

    Photoelectron spectroscopy has the advantage of providing electric potentials by non-contact measurements based on the kinetic energy shift in component potential. We performed operando hard X-ray photoelectron spectroscopy (HAXPES) measurements with an 8 keV excitation source to measure the shift in electron kinetic energies as a function of the voltages of all the components at the anode and cathode electrodes of a polymer electrolyte fuel cell (PEFC). At the cathode electrode, when we increase the voltage between the cathode and anode from 0.2 to 1.2 V, the O 1s and F 1s peaks shift to a lower binding energy and the magnitude of the energy shift is equal to the voltage. The Pt 3d and C 1s peaks do not shift with the voltage since platinum nanoparticles and carbon supports at the cathode electrode have ground contact. In contrast to the cathode electrode, the peak shifts of all the components at the anode electrode show the same amount of shift as the voltages. It is clear that the change in the potential difference occurs only in an electrical double layer at the interface between the cathode electrode (Pt/C) and the electrolyte (Nafion and water), and that the anode electrode is in equilibrium as a pseudo-hydrogen electrode. Moreover, the electric potential variation of the cathode electrode in a PEFC under a power generation condition was also directly detected by operando HAXPES.

  13. Conformational studies of self-organized regioregular poly(3-dodecylthiophene)s using non-contact atomic force microscopy in ultra high vacuum condition

    International Nuclear Information System (INIS)

    Tanaka, Shukichi; Grevin, Benjamin; Rannou, Patrice; Suzuki, Hitoshi; Mashiko, Shinro

    2006-01-01

    Conformations of one of the variations of π-conjugated poly-alkylthiophene, poly(3-dodecylthiophene)s (P3DDT)s on the surface in ultra high vacuum (UHV) were investigated by non-contact atomic force microscopy (NC-AFM) operated by frequency-modulation mode (FM-mode). From individual molecules to several multi-layered ones, polymer chains on the surface were clearly resolved on conducting highly oriented pyrolytic graphite (HOPG) substrates and insulating mica ones, respectively. Solvent evaporation was found to have two stages, which influenced the diffusion, ordering, and adhesion processes of polymer chains on the substrate. To keep the ordered conformations of deposited polymer chains when they are transferred from ambient condition to UHV, these evaporation processes should be carefully considered. The initial conformation of polymers on the substrate was found to depend strongly on the lattice matching conditions and interactions between polymers and substrates. Formations of stripe-like structures of P3DDT polymers were found on the mica substrates, which is promising for device application

  14. A Reference-Free and Non-Contact Method for Detecting and Imaging Damage in Adhesive-Bonded Structures Using Air-Coupled Ultrasonic Transducers

    Directory of Open Access Journals (Sweden)

    Timotius Yonathan Sunarsa

    2017-12-01

    Full Text Available Adhesive bonded structures have been widely used in aerospace, automobile, and marine industries. Due to the complex nature of the failure mechanisms of bonded structures, cost-effective and reliable damage detection is crucial for these industries. Most of the common damage detection methods are not adequately sensitive to the presence of weakened bonding. This paper presents an experimental and analytical method for the in-situ detection of damage in adhesive-bonded structures. The method is fully non-contact, using air-coupled ultrasonic transducers (ACT for ultrasonic wave generation and sensing. The uniqueness of the proposed method relies on accurate detection and localization of weakened bonding in complex adhesive bonded structures. The specimens tested in this study are parts of real-world structures with critical and complex damage types, provided by Hyundai Heavy Industries® and IKTS Fraunhofer®. Various transmitter and receiver configurations, including through transmission, pitch-catch scanning, and probe holder angles, were attempted, and the obtained results were analyzed. The method examines the time-of-flight of the ultrasonic waves over a target inspection area, and the spatial variation of the time-of-flight information was examined to visualize and locate damage. The proposed method works without relying on reference data obtained from the pristine condition of the target specimen. Aluminum bonded plates and triplex adhesive layers with debonding and weakened bonding were used to examine the effectiveness of the method.

  15. Use of a laser displacement sensor with a non-contact electromagnetic vibration device for assessment of simulated periodontal tissue conditions.

    Science.gov (United States)

    Kobayashi, Hiroshi; Yamaoka, Masaru; Hayashi, Makoto; Ogiso, Bunnai

    2016-01-01

    A non-contact electromagnetic vibration device (NEVD) was previously developed to monitor the condition of periodontal tissues by assessing mechanical parameters. This system requires placement of an accelerometer on the target tooth, to detect vibration. Using experimental tooth models, we evaluated the performance of an NEVD system with a laser displacement sensor (LDS), which does not need an accelerometer. Simulated teeth (polyacetal rods) were submerged at various depths in simulated bone (polyurethane or polyurethane foam) containing simulated periodontal ligament (tissue conditioner). Then, mechanical parameters (resonant frequency, elastic modulus, and viscosity coefficient) were assessed using the NEVD with the following detection methods: Group 1, measurement with an accelerometer; Group 2, measurement with an LDS in the presence of the accelerometer; and Group 3, measurement with an LDS in the absence of the accelerometer. Statistical analyses were performed using nonparametric methods (n = 5) (P < 0.05). The three mechanical parameters significantly increased with increasing depth. In addition, the mechanical parameters significantly differed between the polyurethane and polyurethane foam models. Although Groups 1 and 2 did not significantly differ, most all mechanical parameters in Group 3 were significantly larger and more distinguishable than those in Groups 1 and 2. The LDS was more accurate in measuring mechanical parameters and better able to differentiate periodontal tissue conditions. (J Oral Sci 58, 93-99, 2016).

  16. Motor teams :

    Indian Academy of Sciences (India)

    Stochastic transitions between two species of motor yields Bidirectional motion. • Tuning of single-motor parameters. • No need to invoke a third “coordination complex”. Page 8. PNAS, 2009. 5.5 pN. 1.1 x 5 = 5.5 pN. Page 9. Kinesin motors have a problem working together. D istance (x) or. Force = Distance * K. TRAP ...

  17. Motor Starters

    Science.gov (United States)

    1986-01-01

    The power factor controller (PFC) was invented by a NASA engineer. It matches voltage with a motor's actual need by sensing shifts in the relationship between voltage and current flow. With the device, power can be trimmed as much as 65%. Intellinet adopted this technology and designed "soft start" and "load-responsive" control modes to start engines gradually and recycle voltage without reducing motor speed. Other features are lower motor heat and faster fault identification.

  18. Linear gate

    International Nuclear Information System (INIS)

    Suwono.

    1978-01-01

    A linear gate providing a variable gate duration from 0,40μsec to 4μsec was developed. The electronic circuity consists of a linear circuit and an enable circuit. The input signal can be either unipolar or bipolar. If the input signal is bipolar, the negative portion will be filtered. The operation of the linear gate is controlled by the application of a positive enable pulse. (author)

  19. Advanced AC Motor Control

    Energy Technology Data Exchange (ETDEWEB)

    Kazmierkowski, M.P. [Institute of Control and Industrial Electronics, Warsaw University of Technology, Warszawa (Poland)

    1997-12-31

    In this paper a review of control methods for high performance PWM inverter-fed induction motor drives is presented. Starting from the description of an induction motor by the help of the space vectors, three basic control strategic are discussed. As first, the most popular Field Oriented Control (FOC) is described. Secondly, the Direct Torque and Flux vector Control (DTFC) method, which - in contrast to FOC - depart from idea of coordinate transformation and analogy with DC motor, is briefly characterized. The last group is based on Feedback Linearization Control (FLC) and can be easy combined with sliding mode control. The simulation and experimental oscillograms that illustrate the performance of the discussed control strategies are shown. (orig.) 35 refs.

  20. Linearization Method and Linear Complexity

    Science.gov (United States)

    Tanaka, Hidema

    We focus on the relationship between the linearization method and linear complexity and show that the linearization method is another effective technique for calculating linear complexity. We analyze its effectiveness by comparing with the logic circuit method. We compare the relevant conditions and necessary computational cost with those of the Berlekamp-Massey algorithm and the Games-Chan algorithm. The significant property of a linearization method is that it needs no output sequence from a pseudo-random number generator (PRNG) because it calculates linear complexity using the algebraic expression of its algorithm. When a PRNG has n [bit] stages (registers or internal states), the necessary computational cost is smaller than O(2n). On the other hand, the Berlekamp-Massey algorithm needs O(N2) where N(≅2n) denotes period. Since existing methods calculate using the output sequence, an initial value of PRNG influences a resultant value of linear complexity. Therefore, a linear complexity is generally given as an estimate value. On the other hand, a linearization method calculates from an algorithm of PRNG, it can determine the lower bound of linear complexity.

  1. Motor teams :

    Indian Academy of Sciences (India)

    . Switch. Welte et al, 1998, Gross et al, 2002. Motion of Lipid droplets in Drosophila embryos. Page 7. • Stochastic transitions between two species of motor yields Bidirectional motion. • Tuning of single-motor parameters. • No need to invoke a ...

  2. Linear position sensing using magnetoresistive sensors

    Energy Technology Data Exchange (ETDEWEB)

    Bratland, T.; Wan, H. [Honeywell Inc., Plymouth, MN (United States). Solid State Electronics Center

    2001-07-01

    This paper presents a non-contact, non-wear-out solution for long span absolute linear position sensing. This solution utilizes an array of magnetoresistive (MR) sensors, a magnet and signal conditioning electronics. The sensors are used to determine the position of a magnet that is attached to a moving object. In addition to mechanical benefits, this solution offers a high accuracy, low power solution. In this paper we will discuss the operating principles, system error and applications of this approach. This approach will be beneficial in applications for linear position or displacement, LVDT replacements, proximity detection, valve positioning, shaft travel, automotive steering, brake and throttle position systems. This will be used in industries including automotive, aviation and industrial process control. (orig.)

  3. Comparison of three methods of tonometry in normal subjects: Goldmann applanation tonometer, non-contact airpuff tonometer, and Tono-Pen XL.

    Science.gov (United States)

    Yilmaz, Ihsan; Altan, Cigdem; Aygit, Ebru Demet; Alagoz, Cengiz; Baz, Okkes; Ahmet, Sibel; Urvasizoglu, Semih; Yasa, Dilek; Demirok, Ahmet

    2014-01-01

    WE AIMED TO COMPARE INTRAOCULAR PRESSURE (IOP) MEASUREMENTS VIA THREE DIFFERENT TONOMETERS: the Goldmann applanation tonometer (GAT), the Tono-Pen(®) XL (TPXL), and a non-contact airpuff tonometer (NCT). This was a cross-sectional study of 200 eyes from 200 patients. Right eyes of all patients were included in this study. IOP was measured via GAT, NCT, and TPXL by three physicians. Each physician used one of the tonometers. Measurements via the three devices were compared. The mean IOP was 15.5±2.2 mmHg (range 10-22) with the GAT, 16.1±3.0 (range 9-25) with the TPXL, and 16.1±2.8 (range 10-26) with the NCT. Bland-Altman analysis showed that the mean difference between measurements from the NCT and the GAT was 0.6±2.3 mmHg. The mean difference between the TPXL and GAT measurements was 0.7±2.5 mmHg. The mean difference between the NCT and TPXL measurements was -0.02±3.0 mmHg. There was no significant difference between the groups according to a one-way analysis of variance (ANOVA) test. P-values were 0.998 for NCT-TPXL, 0.067 for NCT-GAT, and 0.059 for TPXL-GAT. The NCT and TPXL provide IOP measurements comparable to those of the gold standard GAT in normotensive eyes.

  4. Development of a xeno-free non-contact co-culture system for derivation and maintenance of embryonic stem cells using a novel human endometrial cell line.

    Science.gov (United States)

    Desai, Nina; Ludgin, Jennifer; Goldberg, Jeffrey; Falcone, Tommaso

    2013-06-01

    Mouse embryonic fibroblast feeder layers (MEF) have conventionally been used to culture and maintain the pluripotency of embryonic stem cells (ESC). This study explores the potential of using a novel human endometrial cell line to develop a non-xeno, non-contact co-culture system for ESC propagation and derivation. Such xeno-free systems may prove essential for the establishment of clinical grade human ESC lines suitable for therapeutic application. A novel line of human endometrial cells were seeded in a 6-well dish. Filter inserts containing mouse ESCs were placed on these wells and passaged 2-3 times per week. Inner cell masses derived from mouse blastocysts were also cultured on transwells in the presence of the feeder layer. In both cases, staining for SSEA-1, SOX-2, OCT-4 and alkaline phosphatase were used to monitor the retention of stem cells. ESC colonies retained their stem cell morphology and attributes for over 120 days in culture and 44 passages to date. Inner cell mass derived ESC cultures were maintained in a pluripotent state for 45 days, through 6 passages with retention of all stem cell characteristics. The stem cell colonies expressed stem cell specific markers SSEA-1, Sox 2, Oct-4 and alkaline phosphatase. Upon removal of the human feeder layer, there was a distinct change in cell morphology within the colonies and evidence of ESC differentiation. Human feeder layers offer a simple path away from the use of MEF feeder cells or MEF conditioned medium for ESC culture. Furthermore, indirect co-culture using porous membranes to separate the two cell types can prevent contamination of stem cell preparations with feeder cells during passaging.

  5. Linear algebra

    CERN Document Server

    Said-Houari, Belkacem

    2017-01-01

    This self-contained, clearly written textbook on linear algebra is easily accessible for students. It begins with the simple linear equation and generalizes several notions from this equation for the system of linear equations and introduces the main ideas using matrices. It then offers a detailed chapter on determinants and introduces the main ideas with detailed proofs. The third chapter introduces the Euclidean spaces using very simple geometric ideas and discusses various major inequalities and identities. These ideas offer a solid basis for understanding general Hilbert spaces in functional analysis. The following two chapters address general vector spaces, including some rigorous proofs to all the main results, and linear transformation: areas that are ignored or are poorly explained in many textbooks. Chapter 6 introduces the idea of matrices using linear transformation, which is easier to understand than the usual theory of matrices approach. The final two chapters are more advanced, introducing t...

  6. Linear algebra

    CERN Document Server

    Stoll, R R

    1968-01-01

    Linear Algebra is intended to be used as a text for a one-semester course in linear algebra at the undergraduate level. The treatment of the subject will be both useful to students of mathematics and those interested primarily in applications of the theory. The major prerequisite for mastering the material is the readiness of the student to reason abstractly. Specifically, this calls for an understanding of the fact that axioms are assumptions and that theorems are logical consequences of one or more axioms. Familiarity with calculus and linear differential equations is required for understand

  7. Linear algebra

    CERN Document Server

    Liesen, Jörg

    2015-01-01

    This self-contained textbook takes a matrix-oriented approach to linear algebra and presents a complete theory, including all details and proofs, culminating in the Jordan canonical form and its proof. Throughout the development, the applicability of the results is highlighted. Additionally, the book presents special topics from applied linear algebra including matrix functions, the singular value decomposition, the Kronecker product and linear matrix equations. The matrix-oriented approach to linear algebra leads to a better intuition and a deeper understanding of the abstract concepts, and therefore simplifies their use in real world applications. Some of these applications are presented in detailed examples. In several ‘MATLAB-Minutes’ students can comprehend the concepts and results using computational experiments. Necessary basics for the use of MATLAB are presented in a short introduction. Students can also actively work with the material and practice their mathematical skills in more than 300 exerc...

  8. Linear Models

    CERN Document Server

    Searle, Shayle R

    2012-01-01

    This 1971 classic on linear models is once again available--as a Wiley Classics Library Edition. It features material that can be understood by any statistician who understands matrix algebra and basic statistical methods.

  9. Linear algebra

    CERN Document Server

    Berberian, Sterling K

    2014-01-01

    Introductory treatment covers basic theory of vector spaces and linear maps - dimension, determinants, eigenvalues, and eigenvectors - plus more advanced topics such as the study of canonical forms for matrices. 1992 edition.

  10. Linear programming

    CERN Document Server

    Solow, Daniel

    2014-01-01

    This text covers the basic theory and computation for a first course in linear programming, including substantial material on mathematical proof techniques and sophisticated computation methods. Includes Appendix on using Excel. 1984 edition.

  11. Using AC Motors in Robotics

    Directory of Open Access Journals (Sweden)

    Hosein Marzi

    2008-11-01

    Full Text Available It has been proven that fuzzy controllers are capable of controlling non-linear systems where it is cumbersome to develop conventional controllers based on mathematical modeling. This paper describes designing fuzzy controllers for an AC motor run mechanism. It also compares performance of two controllers designed based on Mamdani and Takagi-Sugeno with the conventional control scheme in a short track length, following a high disturbance. Fine and rapid control of AC motors have been a challenge and the main obstacle in gaining popularity in use of AC motors in robots actuators. This chapter reviews how use of intelligent control scheme can help to solve this problem.

  12. Application of stepping motor

    International Nuclear Information System (INIS)

    1980-10-01

    This book is divided into three parts, which is about practical using of stepping motor. The first part has six chapters. The contents of the first part are about stepping motor, classification of stepping motor, basic theory og stepping motor, characteristic and basic words, types and characteristic of stepping motor in hybrid type and basic control of stepping motor. The second part deals with application of stepping motor with hardware of stepping motor control, stepping motor control by microcomputer and software of stepping motor control. The last part mentions choice of stepping motor system, examples of stepping motor, measurement of stepping motor and practical cases of application of stepping motor.

  13. Comparison of three methods of tonometry in normal subjects: Goldmann applanation tonometer, non-contact airpuff tonometer, and Tono-Pen XL

    Directory of Open Access Journals (Sweden)

    Yilmaz I

    2014-06-01

    Full Text Available Ihsan Yilmaz, Cigdem Altan, Ebru Demet Aygit, Cengiz Alagoz, Okkes Baz, Sibel Ahmet, Semih Urvasizoglu, Dilek Yasa, Ahmet DemirokBeyoglu Eye Training and Research Hospital, Istanbul, TurkeyObjective: We aimed to compare intraocular pressure (IOP measurements via three different tonometers: the Goldmann applanation tonometer (GAT, the Tono-Pen® XL (TPXL, and a non-contact airpuff tonometer (NCT.Methods: This was a cross-sectional study of 200 eyes from 200 patients. Right eyes of all patients were included in this study. IOP was measured via GAT, NCT, and TPXL by three physicians. Each physician used one of the tonometers. Measurements via the three devices were compared.Results: The mean IOP was 15.5±2.2 mmHg (range 10–22 with the GAT, 16.1±3.0 (range 9–25 with the TPXL, and 16.1±2.8 (range 10–26 with the NCT. Bland–Altman analysis showed that the mean difference between measurements from the NCT and the GAT was 0.6±2.3 mmHg. The mean difference between the TPXL and GAT measurements was 0.7±2.5 mmHg. The mean difference between the NCT and TPXL measurements was −0.02±3.0 mmHg. There was no significant difference between the groups according to a one-way analysis of variance (ANOVA test. P-values were 0.998 for NCT–TPXL, 0.067 for NCT–GAT, and 0.059 for TPXL–GAT.Conclusion: The NCT and TPXL provide IOP measurements comparable to those of the gold standard GAT in normotensive eyes.Keywords: tonometry, noncontact tonometry, Goldmann applanation tonometer, Tono-Pen

  14. Linear regression

    CERN Document Server

    Olive, David J

    2017-01-01

    This text covers both multiple linear regression and some experimental design models. The text uses the response plot to visualize the model and to detect outliers, does not assume that the error distribution has a known parametric distribution, develops prediction intervals that work when the error distribution is unknown, suggests bootstrap hypothesis tests that may be useful for inference after variable selection, and develops prediction regions and large sample theory for the multivariate linear regression model that has m response variables. A relationship between multivariate prediction regions and confidence regions provides a simple way to bootstrap confidence regions. These confidence regions often provide a practical method for testing hypotheses. There is also a chapter on generalized linear models and generalized additive models. There are many R functions to produce response and residual plots, to simulate prediction intervals and hypothesis tests, to detect outliers, and to choose response trans...

  15. Linear algebra

    CERN Document Server

    Edwards, Harold M

    1995-01-01

    In his new undergraduate textbook, Harold M Edwards proposes a radically new and thoroughly algorithmic approach to linear algebra Originally inspired by the constructive philosophy of mathematics championed in the 19th century by Leopold Kronecker, the approach is well suited to students in the computer-dominated late 20th century Each proof is an algorithm described in English that can be translated into the computer language the class is using and put to work solving problems and generating new examples, making the study of linear algebra a truly interactive experience Designed for a one-semester course, this text adopts an algorithmic approach to linear algebra giving the student many examples to work through and copious exercises to test their skills and extend their knowledge of the subject Students at all levels will find much interactive instruction in this text while teachers will find stimulating examples and methods of approach to the subject

  16. MOTORIZATION IN ASIA

    Directory of Open Access Journals (Sweden)

    Metin SENBIL

    2007-01-01

    Full Text Available Motorization in terms of passenger cars in 14 Asian countries and passenger cars and motorcycles in three metropolitan areas are analyzed in this study. Using country-based data which cover 20 years (1980–2000, a linear regression is conducted by panel estimation with random and fixed effects. As a result from the model, fixed income elasticity for the region was found to be 1.75. Fixed effect estimated separately for each country characterizes the motorization pace in the countries. Two groups of countries were detected with a significant difference in motorization paces—Sri Lanka, India, Nepal, Philippines, Pakistan, Indonesia and Thailand have motorization paces higher than the rest of the countries. Additionally, using a cross-sectional data household car and motorcycle ownerships were analyzed for three metropolitan areas characterizing South-East Asia that are Jabotabek (Indonesia, Kuala Lumpur (Malaysia and Manila (Philippines metropolitan areas. Results indicate that ownership of cars and motorcycles are independent of each other in Jabotabek and Manila, but negatively correlated in Kuala Lumpur; and generally, income is more influential on car ownership than motorcycle ownership.

  17. Linear programming

    CERN Document Server

    Karloff, Howard

    1991-01-01

    To this reviewer’s knowledge, this is the first book accessible to the upper division undergraduate or beginning graduate student that surveys linear programming from the Simplex Method…via the Ellipsoid algorithm to Karmarkar’s algorithm. Moreover, its point of view is algorithmic and thus it provides both a history and a case history of work in complexity theory. The presentation is admirable; Karloff's style is informal (even humorous at times) without sacrificing anything necessary for understanding. Diagrams (including horizontal brackets that group terms) aid in providing clarity. The end-of-chapter notes are helpful...Recommended highly for acquisition, since it is not only a textbook, but can also be used for independent reading and study. —Choice Reviews The reader will be well served by reading the monograph from cover to cover. The author succeeds in providing a concise, readable, understandable introduction to modern linear programming. —Mathematics of Computing This is a textbook intend...

  18. THE MOTOR

    DEFF Research Database (Denmark)

    Gammelgaard Nielsen, Anders

    2011-01-01

    MOTOR is the first assignment that students at Unit 1a of the School of Architecture are introduced to. The purpose of the assignment is to shake up the students and their preconceptions of what architec- ture is. This is done by introducing them to a working method that al- lows them to develop ...

  19. THE MOTOR

    DEFF Research Database (Denmark)

    Gammelgaard Nielsen, Anders

    2011-01-01

    MOTOR is the first assignment that students at Unit 1a of the School of Architecture are introduced to. The purpose of the assignment is to shake up the students and their preconceptions of what architec- ture is. This is done by introducing them to a working method that al- lows them to develop...

  20. Motor learning.

    Science.gov (United States)

    Wolpert, Daniel M; Flanagan, J Randall

    2010-06-08

    Although learning a motor skill, such as a tennis stroke, feels like a unitary experience, researchers who study motor control and learning break the processes involved into a number of interacting components. These components can be organized into four main groups. First, skilled performance requires the effective and efficient gathering of sensory information, such as deciding where and when to direct one's gaze around the court, and thus an important component of skill acquisition involves learning how best to extract task-relevant information. Second, the performer must learn key features of the task such as the geometry and mechanics of the tennis racket and ball, the properties of the court surface, and how the wind affects the ball's flight. Third, the player needs to set up different classes of control that include predictive and reactive control mechanisms that generate appropriate motor commands to achieve the task goals, as well as compliance control that specifies, for example, the stiffness with which the arm holds the racket. Finally, the successful performer can learn higher-level skills such as anticipating and countering the opponent's strategy and making effective decisions about shot selection. In this Primer we shall consider these components of motor learning using as an example how we learn to play tennis. 2010 Elsevier Ltd. All rights reserved.

  1. Performance test of 100 W linear compressor

    International Nuclear Information System (INIS)

    Ko, J; Ko, D. Y.; Park, S. J.; Kim, H. B.; Hong, Y. J.; Yeom, H. K.

    2013-01-01

    In this paper, we present test results of developed 100 W class linear compressor for Stirling-type pulse tube refrigerator. The fabricated linear compressor has dual-opposed configuration, free piston and moving magnet type linear motor. Power transfer, efficiency and required pressure waveform are predicted with designed and measured specifications. In experiments, room temperature test with flow impedance is conducted to evaluate performance of developed linear compressor. Flow impedance is loaded to compressor with metering valve for flow resistance, inertance tube for flow inertance and buffer volumes for flow compliance. Several operating parameters such as input voltage, current, piston displacement and pressure wave are measured for various operating frequency and fixed input current level. Behaviors of dynamics and performance of linear compressor as varying flow impedance are discussed with measured experimental results. The developed linear compressor shows 124 W of input power, 86 % of motor efficiency and 60 % of compressor efficiency at its resonant operating condition.

  2. Linear systems

    CERN Document Server

    Bourlès, Henri

    2013-01-01

    Linear systems have all the necessary elements (modeling, identification, analysis and control), from an educational point of view, to help us understand the discipline of automation and apply it efficiently. This book is progressive and organized in such a way that different levels of readership are possible. It is addressed both to beginners and those with a good understanding of automation wishing to enhance their knowledge on the subject. The theory is rigorously developed and illustrated by numerous examples which can be reproduced with the help of appropriate computation software. 60 exe

  3. A Cryogenic High-Power-Density Bearingless Motor for Future Electric Propulsion

    Science.gov (United States)

    Choi, Benjamin; Siebert, Mark

    2008-01-01

    The NASA Glenn Research Center (GRC) is developing a high-power-density switched-reluctance cryogenic motor for all-electric and pollution-free flight. However, cryogenic operation at higher rotational speeds markedly shortens the life of mechanical rolling element bearings. Thus, to demonstrate the practical feasibility of using this motor for future flights, a non-contact rotor-bearing system is a crucial technology to circumvent poor bearing life that ordinarily accompanies cryogenic operation. In this paper, a bearingless motor control technology for a 12-8 (12 poles in the stator and 8 poles in the rotor) switched-reluctance motor operating in liquid nitrogen (boiling point, 77 K (-196 C or -321 F)) was presented. We pushed previous disciplinary limits of electromagnetic controller technique by extending the state-of-the-art bearingless motor operating at liquid nitrogen for high-specific-power applications. The motor was levitated even in its nonlinear region of magnetic saturation, which is believed to be a world first for the motor type. Also we used only motoring coils to generate motoring torque and levitation force, which is an important feature for developing a high specific power motor.

  4. Reduction of Linear Programming to Linear Approximation

    OpenAIRE

    Vaserstein, Leonid N.

    2006-01-01

    It is well known that every Chebyshev linear approximation problem can be reduced to a linear program. In this paper we show that conversely every linear program can be reduced to a Chebyshev linear approximation problem.

  5. Jidosha's Motors

    OpenAIRE

    Shirakawa Okuma, Rosely; Calderón Orejuela, Javier

    2016-01-01

    La tesis narra la situación de una empresa concesionaria de vehículos nuevos, Jidosha's Motors, perteneciente a una corporación japonesa que cuenta con una cultura muy arraigada de ética y de cumplimiento. Se plantean respuestas, se identifican problemas y sus alternativas de solución para una toma adecuada de decisiones por parte de los directivos, siguiendo una estructura de análisis de situaciones de negocios (ASN). Tesis

  6. Split-Stirling-cycle displacer linear-electric drive

    Science.gov (United States)

    Ackermann, R. A.; Bhate, S. K.; Byrne, D. V.

    1983-01-01

    The retrofit of a 1/4-W split-Stirling cooler with a linear driven on the displacer was achieved and its performance characterized. The objective of this work was to demonstrate that a small linear motor could be designed to meet the existing envelope specifications of the cooler and that an electric linear drive on the displacer could improve the cooler's reliability and performance. The paper describes the characteristics of this motor and presents cooler test results.

  7. FPGA based control of a walking piezo motor

    OpenAIRE

    Uzunovic, Tarik; Golubovic, Edin; Şabanoviç, Asif; Sabanovic, Asif

    2014-01-01

    This paper describes FPGA based control system for a piezoelectric motor, commercially available Piezo LEGS motor. Driving voltages waveforms are defined as a combination of linear functions. This definition provides possibility for easy implementation on very simple hardware. Linear functions parameters allow forming of the driving voltages according to desired trajectory of motor's legs. Considering that FPGA technology offers many advantages over the classical microprocessor based systems,...

  8. Acute non-contact anterior cruciate ligament tears are associated with relatively increased vastus medialis to semimembranosus cross-sectional area ratio: a case-control retrospective MR study

    Energy Technology Data Exchange (ETDEWEB)

    Wieschhoff, Ged G.; Mandell, Jacob C.; Czuczman, Gregory J.; Nikac, Violeta; Shah, Nehal; Smith, Stacy E. [Brigham and Women' s Hospital, Harvard Medical School, Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States)

    2017-11-15

    Hamstring muscle deficiency is increasingly recognized as a risk factor for anterior cruciate ligament (ACL) tears. The purpose of this study is to evaluate the vastus medialis to semimembranosus cross-sectional area (VM:SM CSA) ratio on magnetic resonance imaging (MRI) in patients with ACL tears compared to controls. One hundred knee MRIs of acute ACL tear patients and 100 age-, sex-, and side-matched controls were included. Mechanism of injury, contact versus non-contact, was determined for each ACL tear subject. The VM:SM CSA was measured on individual axial slices with a novel method using image-processing software. One reader measured all 200 knees and the second reader measured 50 knees at random to assess inter-reader variability. The intraclass correlation coefficient (ICC) was calculated to evaluate for correlation between readers. T-tests were performed to evaluate for differences in VM:SM CSA ratios between the ACL tear group and control group. The ICC for agreement between the two readers was 0.991 (95% confidence interval 0.984-0.995). Acute ACL tear patients have an increased VM:SM CSA ratio compared to controls (1.44 vs. 1.28; p = 0.005). Non-contact acute ACL tear patients have an increased VM:SM CSA ratio compared to controls (1.48 vs. 1.20; p = 0.003), whereas contact acute ACL tear patients do not (1.23 vs. 1.26; p = 0.762). Acute non-contact ACL tears are associated with increased VM:SM CSA ratios, which may imply a relative deficiency in hamstring strength. This study also demonstrates a novel method of measuring the relative CSA of muscles on MRI. (orig.)

  9. T-Slide Linear Actuators

    Science.gov (United States)

    Vranish, John

    2009-01-01

    T-slide linear actuators use gear bearing differential epicyclical transmissions (GBDETs) to directly drive a linear rack, which, in turn, performs the actuation. Conventional systems use a rotary power source in conjunction with a nut and screw to provide linear motion. Non-back-drive properties of GBDETs make the new actuator more direct and simpler. Versions of this approach will serve as a long-stroke, ultra-precision, position actuator for NASA science instruments, and as a rugged, linear actuator for NASA deployment duties. The T slide can operate effectively in the presence of side forces and torques. Versions of the actuator can perform ultra-precision positioning. A basic T-slide actuator is a long-stroke, rack-and-pinion linear actuator that, typically, consists of a T-slide, several idlers, a transmission to drive the slide (powered by an electric motor) and a housing that holds the entire assembly. The actuator is driven by gear action on its top surface, and is guided and constrained by gear-bearing idlers on its other two parallel surfaces. The geometry, implemented with gear-bearing technology, is particularly effective. An electronic motor operating through a GBDET can directly drive the T slide against large loads, as a rack and pinion linear actuator, with no break and no danger of back driving. The actuator drives the slide into position and stops. The slide holes position with power off and no brake, regardless of load. With the T slide configuration, this GBDET has an entire T-gear surface on which to operate. The GB idlers coupling the other two T slide parallel surfaces to their housing counterpart surfaces provide constraints in five degrees-of-freedom and rolling friction in the direction of actuation. Multiple GB idlers provide roller bearing strength sufficient to support efficient, rolling friction movement, even in the presence of large, resisting forces. T-slide actuators can be controlled using the combination of an off

  10. Direct linear driving systems; Les entrainements lineaires directs

    Energy Technology Data Exchange (ETDEWEB)

    Favre, E.; Brunner, C.; Piaget, D. [ETEL SA (France)

    1999-11-01

    The linear motor is one of the most important developments in electrical drive technology. However, it only, began to be adopted on a large scale at the beginning of the 1990's and will not be considered a mature technology until well into the next millennium. Actuators based on linear motor technology have a number of technical advantages including high speed, high positional accuracy and fine resolution. They also require fewer component parts. Some precautions are necessary when using linear motors. Care must be taken to avoid overheating and excessive vibration, and the magnetic components must be protected.

  11. IRON DEFICIENCY AND INFANT MOTOR DEVELOPMENT

    Science.gov (United States)

    Shafir, Tal; Angulo-Barroso, Rosa; Jing, Yuezhou; Lu Angelilli, Mary; Jacobson, Sandra W.; Lozoff, Betsy

    2011-01-01

    Background Iron deficiency (ID) during early development impairs myelination and basal ganglia function in animal models. Aims To examine the effects of iron deficiency anemia (IDA) and iron deficiency (ID) without anemia on infant motor skills that are likely related to myelination and basal ganglia function. Study design Observational study. Subjects Full-term inner-city African-American 9- to 10-month-old infants who were free of acute or chronic health problems with iron status indicators ranging from IDA to iron sufficiency (n = 106). Criteria for final iron status classification were met by 77 of these infants: 28 IDA, 28 non-anemic iron-deficient (NA ID), and 21 iron-sufficient (IS). Outcome measures Gross motor developmental milestones, Peabody Developmental Motor Scale, Infant Neurological International Battery (INFANIB), motor quality factor of the Bayley Behavioral Rating Scale, and a sequential/bi-manual coordination toy retrieval task. General linear model analyses tested for linear effects of iron status group and thresholds for effects. Results There were linear effects of iron status on developmental milestones, Peabody gross motor (suggestive trend), INFANIB standing item, motor quality, and toy retrieval. The threshold for effects was ID with or without anemia for developmental milestones, INFANIB standing item, and motor quality and IDA for toy retrieval. Conclusions Using a comprehensive and sensitive assessment of motor development, this study found poorer motor function in ID infants with and without anemia. Poorer motor function among non-anemic ID infants is particularly concerning, since ID without anemia is not detected by common screening procedures and is more widespread than IDA. PMID:18272298

  12. Non-linear dynamics in Parkinsonism

    Directory of Open Access Journals (Sweden)

    Olivier eDarbin

    2013-12-01

    Full Text Available Over the last 30 years, the functions (and dysfunctions of the sensory-motor circuitry have been mostly conceptualized using linear modelizations which have resulted in two main models: the "rate hypothesis" and the "oscillatory hypothesis". In these two models, the basal ganglia data stream is envisaged as a random temporal combination of independent simple patterns issued from its probability distribution of interval interspikes or its spectrum of frequencies respectively.More recently, non-linear analyses have been introduced in the modelization of motor circuitry activities, and they have provided evidences that complex temporal organizations exist in basal ganglia neuronal activities. Regarding movement disorders, these complex temporal organizations in the basal ganglia data stream differ between conditions (i.e. parkinsonism, dyskinesia, healthy control and are responsive to treatments (i.e. L-DOPA,DBS. A body of evidence has reported that basal ganglia neuronal entropy (a marker for complexity/irregularity in time series is higher in hypokinetic state. In line with these findings, an entropy-based model has been recently formulated to introduce basal ganglia entropy as a marker for the alteration of motor processing and a factor of motor inhibition. Importantly, non-linear features have also been identified as a marker of condition and/or treatment effects in brain global signals (EEG, muscular activities (EMG or kinetic of motor symptoms (tremor, gait of patients with movement disorders. It is therefore warranted that the non-linear dynamics of motor circuitry will contribute to a better understanding of the neuronal dysfunctions underlying the spectrum of parkinsonian motor symptoms including tremor, rigidity and hypokinesia.

  13. Gross motor control

    Science.gov (United States)

    Gross motor control is the ability to make large, general movements (such as waving an arm or lifting a ... Gross motor control is a milestone in the development of an infant. Infants develop gross motor control before they ...

  14. Analysis of non-contact and contact probe-to-sample thermal exchange for quantitative measurements of thin film and nanostructure thermal conductivity by the scanning hot probe method

    Science.gov (United States)

    Wilson, Adam A.

    The ability to measure thermal properties of thin films and nanostructured materials is an important aspect of many fields of academic study. A strategy especially well-suited for nanoscale investigations of these properties is the scanning hot probe technique, which is unique in its ability to non-destructively interrogate the thermal properties with high resolution, both laterally as well as through the thickness of the material. Strategies to quantitatively determine sample thermal conductivity depend on probe calibration. State of the art calibration strategies assume that the area of thermal exchange between probe and sample does not vary with sample thermal conductivity. However, little investigation has gone into determining whether or not that assumption is valid. This dissertation provides a rigorous study into the probe-to-sample heat transfer through the air gap at diffusive distances for a variety of values of sample thermal conductivity. It is demonstrated that the thermal exchange radius and gap/contact thermal resistance varies with sample thermal conductivity as well as tip-to-sample clearance in non-contact mode. In contact mode, it is demonstrated that higher thermal conductivity samples lead to a reduction in thermal exchange radius for Wollaston probe tips. Conversely, in non-contact mode and in contact mode for sharper probe tips where air contributes the most to probe-to-sample heat transfer, the opposite trend occurs. This may be attributed to the relatively strong solid-to-solid conduction occurring between probe and sample for the Wollaston probes. A three-dimensional finite element (3DFE) model was developed to investigate how the calibrated thermal exchange parameters vary with sample thermal conductivity when calibrating the probe via the intersection method in non-contact mode at diffusive distances. The 3DFE model was then used to explore the limits of sensitivity of the experiment for a range of simulated experimental conditions. It

  15. Magnet pole shape design for reduction of thrust ripple of slotless permanent magnet linear synchronous motor with arc-shaped magnets considering end-effect based on analytical method

    Directory of Open Access Journals (Sweden)

    Kyung-Hun Shin

    2017-05-01

    Full Text Available The shape of the magnet is essential to the performance of a slotless permanent magnet linear synchronous machine (PMLSM because it is directly related to desirable machine performance. This paper presents a reduction in the thrust ripple of a PMLSM through the use of arc-shaped magnets based on electromagnetic field theory. The magnetic field solutions were obtained by considering end effect using a magnetic vector potential and two-dimensional Cartesian coordinate system. The analytical solution of each subdomain (PM, air-gap, coil, and end region is derived, and the field solution is obtained by applying the boundary and interface conditions between the subdomains. In particular, an analytical method was derived for the instantaneous thrust and thrust ripple reduction of a PMLSM with arc-shaped magnets. In order to demonstrate the validity of the analytical results, the back electromotive force results of a finite element analysis and experiment on the manufactured prototype model were compared. The optimal point for thrust ripple minimization is suggested.

  16. 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.

  17. New Zealand rugby health study: motor cortex excitability in retired elite and community level rugby players.

    Science.gov (United States)

    Lewis, Gwyn N; Hume, Patria A; Stavric, Verna; Brown, Scott R; Taylor, Denise

    2017-01-13

    Rugby union is a high contact sport in which players frequently experience brain injuries. Acute brain injury is associated with altered corticomotor function. However, it is uncertain if long-term exposure to rugby is associated with any alterations in corticomotor function. The aim of the study was to assess measures of corticomotor excitability and inhibition in retired rugby players in comparison to retired non-contact sport players. The design was a cross-sectional study with three groups of retired athletes: elite rugby (n=23), community level rugby (n=28) and non-contact sport control (n=22). Assessments of corticomotor excitability were made using transcranial magnetic stimulation. Resting motor threshold was significantly higher and long-interval intracortical inhibition was greater in the elite rugby group compared to the control group. Participants in the two rugby groups had sustained significantly more concussions than the control group. We provide some evidence of altered corticomotor excitation and inhibition in retired elite rugby players in comparison to retired non-contact sport players. Given the absence of findings in the community rugby group, who had experienced a similar number of concussions, the association with previous brain injury is unclear.

  18. Linear Algebra and Smarandache Linear Algebra

    OpenAIRE

    Vasantha, Kandasamy

    2003-01-01

    The present book, on Smarandache linear algebra, not only studies the Smarandache analogues of linear algebra and its applications, it also aims to bridge the need for new research topics pertaining to linear algebra, purely in the algebraic sense. We have introduced Smarandache semilinear algebra, Smarandache bilinear algebra and Smarandache anti-linear algebra and their fuzzy equivalents. Moreover, in this book, we have brought out the study of linear algebra and vector spaces over finite p...

  19. High efficiency motors; Motores de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Uranga Favela, Ivan Jaime [Energia Controlada de Mexico, S. A. de C. V., Mexico, D. F. (Mexico)

    1992-12-31

    This paper is a technical-financial study of the high efficiency and super-premium motors. As it is widely known, more than 60% of the electrical energy generated in the country is used for the operation of motors, in industry as well as in commerce. Therefore the importance that the motors have in the efficient energy use. [Espanol] El presente trabajo es un estudio tecnico-financiero de los motores de alta eficiencia y los motores super premium. Como es ampliamente conocido, mas del 60% de la energia electrica generada en el pais, es utilizada para accionar motores, dentro de la industria y el comercio. De alli la importancia que los motores tienen en el uso eficiente de la energia.

  20. Features of Synchronous Electronically Commutated Motors in Servomotor Operation Modes

    Directory of Open Access Journals (Sweden)

    Dirba J.

    2017-04-01

    Full Text Available The authors consider the features and operation specifics of the synchronous permanent magnet motors and the synchronous reluctance motors with electronic commutation in servomotor operation modes. Calculation results show that mechanical and control characteristics of studied motors are close to a linear shape. The studied motor control is proposed to implement similar to phase control of induction servomotor; it means that angle θ (angle between vectors of the supply voltage and non-load electromotive force or angle ε (angle between rotor direct axis and armature magnetomotive force axis is changed. The analysis results show that synchronous electronically commutated motors could be used as servomotors.

  1. Motor Priming in Neurorehabilitation

    OpenAIRE

    Stoykov, Mary Ellen; Madhavan, Sangeetha

    2015-01-01

    Priming is a type of implicit learning wherein a stimulus prompts a change in behavior. Priming has been long studied in the field of psychology. More recently, rehabilitation researchers have studied motor priming as a possible way to facilitate motor learning. For example, priming of the motor cortex is associated with changes in neuroplasticity that are associated with improvements in motor performance. Of the numerous motor priming paradigms under investigation, only a few ...

  2. AC Application of HTS Conductors in Highly Dynamic Electric Motors

    International Nuclear Information System (INIS)

    Oswald, B; Best, K-J; Setzer, M; Duffner, E; Soell, M; Gawalek, W; Kovalev, L K

    2006-01-01

    Based on recent investigations we design highly dynamic electric motors up to 400 kW and linear motors up to 120 kN linear force using HTS bulk material and HTS tapes. The introduction of HTS tapes into AC applications in electric motors needs fundamental studies on double pancake coils under transversal magnetic fields. First theoretical and experimental results on AC field distributions in double-pancake-coils and corresponding AC losses will be presented. Based on these results the simulation of the motor performance confirms extremely high power density and efficiency of both types of electric motors. Improved characteristics of rare earth permanent magnets used in our motors at low temperatures give an additional technological benefit

  3. Non-contact method for directing electrotaxis

    Science.gov (United States)

    Ahirwar, Dinesh K.; Nasser, Mohd W.; Jones, Travis H.; Sequin, Emily K.; West, Joseph D.; Henthorne, Timothy L.; Javor, Joshua; Kaushik, Aniruddha M.; Ganju, Ramesh K.; Subramaniam, Vish V.

    2015-06-01

    We present a method to induce electric fields and drive electrotaxis (galvanotaxis) without the need for electrodes to be in contact with the media containing the cell cultures. We report experimental results using a modification of the transmembrane assay, demonstrating the hindrance of migration of breast cancer cells (SCP2) when an induced a.c. electric field is present in the appropriate direction (i.e. in the direction of migration). Of significance is that migration of these cells is hindered at electric field strengths many orders of magnitude (5 to 6) below those previously reported for d.c. electrotaxis, and even in the presence of a chemokine (SDF-1α) or a growth factor (EGF). Induced a.c. electric fields applied in the direction of migration are also shown to hinder motility of non-transformed human mammary epithelial cells (MCF10A) in the presence of the growth factor EGF. In addition, we also show how our method can be applied to other cell migration assays (scratch assay), and by changing the coil design and holder, that it is also compatible with commercially available multi-well culture plates.

  4. Ferroelectret non-contact ultrasonic transducers

    Czech Academy of Sciences Publication Activity Database

    Bovtun, Viktor; Döring, J.; Bartusch, J.; Beck, U.; Erhard, A.; Yakymenko, Y.

    2007-01-01

    Roč. 88, č. 4 (2007), s. 737-743 ISSN 0947-8396 R&D Projects: GA ČR(CZ) GA202/06/0403 Institutional research plan: CEZ:AV0Z10100520 Keywords : ferroelectrets * polymers * ultrasonic transducers Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.857, year: 2007

  5. Non-contact radiation thickness gauge

    International Nuclear Information System (INIS)

    Tsujii, T.; Okino, T.

    1983-01-01

    A noncontact thickness gauge system for measuring the thickness of a material comprising a source of radiation, a detector for detecting the amount of radiation transmitted through the material which is a function of the absorptance and thickness of the material, a memory for storing the output signals of the detector and curve-defining parameters for a plurality of quadratic calibration curves which correspond to respective thickness ranges, and a processor for processing the signals and curve defining parameters to determine the thickness of the material. Measurements are made after precalibration to obtain calibration curves and these are stored in the memory, providing signals representative of a nominal thickness and an alloy compensation coefficient for the material. The calibration curve corresponding to a particular thickness range is selected and the curve compensated for drift; the material is inserted into the radiation path and the detector output signal processed with the compensated calibration curve to determine the thickness of the material. (author)

  6. Non-contact lens relatedAcanthamoebakeratitis.

    Science.gov (United States)

    Garg, Prashant; Kalra, Paavan; Joseph, Joveeta

    2017-11-01

    The purpose of the study is to describe epidemiology, clinical features, diagnosis, and treatment of Acanthamoeba keratitis (AK) with special focus on the disease in nonusers of contact lenses (CLs). This study was a perspective based on authors' experience and review of published literature. AK accounts for 2% of microbiology-proven cases of keratitis. Trauma and exposure to contaminated water are the main predisposing factors for the disease. Association with CLs is seen only in small fraction of cases. Contrary to classical description experience in India suggests that out of proportion pain, ring infiltrate, and radial keratoneuritis are seen in less than a third of cases. Majority of cases present with diffuse infiltrate, mimicking herpes simplex or fungal keratitis. The diagnosis can be confirmed by microscopic examination of corneal scraping material and culture on nonnutrient agar with an overlay of Escherichia coli. Confocal microscopy can help diagnosis in patients with deep infiltrate; however, experience with technique and interpretation of images influences its true value. Primary treatment of the infection is biguanides with or without diamidines. Most patients respond to medical treatment. Corticosteroids play an important role in the management and can be used when indicated after due consideration to established protocols. Surgery is rarely needed in patients where definitive management is initiated within 3 weeks of onset of symptoms. Lamellar keratoplasty has been shown to have good outcome in cases needing surgery. Since the clinical features of AK in nonusers of CL are different, it will be important for ophthalmologists to be aware of the scenario wherein to suspect this infection. Medical treatment is successful if the disease is diagnosed early and management is initiated soon.

  7. EPro Non-contact erosion profiling

    DEFF Research Database (Denmark)

    Meinert, Palle

    EPro is a profiler controlled by software, which is constructed to measure the same surface or work piece multiple times and track changes due to erosion.......EPro is a profiler controlled by software, which is constructed to measure the same surface or work piece multiple times and track changes due to erosion....

  8. EPro Non-contact erosion profiling

    DEFF Research Database (Denmark)

    Meinert, Palle

    Pro is a profiling program build to measure the same surface or work piece multiple times and track changes due to erosion. It was developed during 2001 - 2002 at Aalborg University and was part of a Master of Science project dealing with stability of rubble mound breakwaters. The goal was to aut......Pro is a profiling program build to measure the same surface or work piece multiple times and track changes due to erosion. It was developed during 2001 - 2002 at Aalborg University and was part of a Master of Science project dealing with stability of rubble mound breakwaters. The goal...

  9. Non-contact lens related Acanthamoeba keratitis

    Directory of Open Access Journals (Sweden)

    Prashant Garg

    2017-01-01

    Full Text Available The purpose of the study is to describe epidemiology, clinical features, diagnosis, and treatment of Acanthamoeba keratitis (AK with special focus on the disease in nonusers of contact lenses (CLs. This study was a perspective based on authors' experience and review of published literature. AK accounts for 2% of microbiology-proven cases of keratitis. Trauma and exposure to contaminated water are the main predisposing factors for the disease. Association with CLs is seen only in small fraction of cases. Contrary to classical description experience in India suggests that out of proportion pain, ring infiltrate, and radial keratoneuritis are seen in less than a third of cases. Majority of cases present with diffuse infiltrate, mimicking herpes simplex or fungal keratitis. The diagnosis can be confirmed by microscopic examination of corneal scraping material and culture on nonnutrient agar with an overlay of Escherichia coli. Confocal microscopy can help diagnosis in patients with deep infiltrate; however, experience with technique and interpretation of images influences its true value. Primary treatment of the infection is biguanides with or without diamidines. Most patients respond to medical treatment. Corticosteroids play an important role in the management and can be used when indicated after due consideration to established protocols. Surgery is rarely needed in patients where definitive management is initiated within 3 weeks of onset of symptoms. Lamellar keratoplasty has been shown to have good outcome in cases needing surgery. Since the clinical features of AK in nonusers of CL are different, it will be important for ophthalmologists to be aware of the scenario wherein to suspect this infection. Medical treatment is successful if the disease is diagnosed early and management is initiated soon.

  10. Non-contact lens related Acanthamoeba keratitis

    Science.gov (United States)

    Garg, Prashant; Kalra, Paavan; Joseph, Joveeta

    2017-01-01

    The purpose of the study is to describe epidemiology, clinical features, diagnosis, and treatment of Acanthamoeba keratitis (AK) with special focus on the disease in nonusers of contact lenses (CLs). This study was a perspective based on authors’ experience and review of published literature. AK accounts for 2% of microbiology-proven cases of keratitis. Trauma and exposure to contaminated water are the main predisposing factors for the disease. Association with CLs is seen only in small fraction of cases. Contrary to classical description experience in India suggests that out of proportion pain, ring infiltrate, and radial keratoneuritis are seen in less than a third of cases. Majority of cases present with diffuse infiltrate, mimicking herpes simplex or fungal keratitis. The diagnosis can be confirmed by microscopic examination of corneal scraping material and culture on nonnutrient agar with an overlay of Escherichia coli. Confocal microscopy can help diagnosis in patients with deep infiltrate; however, experience with technique and interpretation of images influences its true value. Primary treatment of the infection is biguanides with or without diamidines. Most patients respond to medical treatment. Corticosteroids play an important role in the management and can be used when indicated after due consideration to established protocols. Surgery is rarely needed in patients where definitive management is initiated within 3 weeks of onset of symptoms. Lamellar keratoplasty has been shown to have good outcome in cases needing surgery. Since the clinical features of AK in nonusers of CL are different, it will be important for ophthalmologists to be aware of the scenario wherein to suspect this infection. Medical treatment is successful if the disease is diagnosed early and management is initiated soon. PMID:29133630

  11. Very Slow Speed Axial Motion Reluctance Motor | Agu | Nigerian ...

    African Journals Online (AJOL)

    Abstract. This paper presents the scheme for a very slow speed linear machine which uses conventional laminations and with which speeds of the same low order as that of the screw-thread motor can be obtained.

  12. Unidirectional Light-Driven Molecular Motors Based on Overcrowded Alkenes

    NARCIS (Netherlands)

    Cnossen, Arjen; Browne, Wesley R.; Feringa, Ben L.; Credi, Alberto; Silvi, Serena; Venturi, Margherita

    2014-01-01

    Over the last two decades, interest in nanotechnology has led to the design and synthesis of a toolbox of nanoscale versions of macroscopic devices and components. In molecular nanotechnology, linear motors based on rotaxanes and rotary motors based on overcrowded alkenes are particularly promising

  13. Imparting Motion to a Test Object Such as a Motor Vehicle in a Controlled Fashion

    Science.gov (United States)

    Southward, Stephen C. (Inventor); Reubush, Chandler (Inventor); Pittman, Bryan (Inventor); Roehrig, Kurt (Inventor); Gerard, Doug (Inventor)

    2014-01-01

    An apparatus imparts motion to a test object such as a motor vehicle in a controlled fashion. A base has mounted on it a linear electromagnetic motor having a first end and a second end, the first end being connected to the base. A pneumatic cylinder and piston combination have a first end and a second end, the first end connected to the base so that the pneumatic cylinder and piston combination is generally parallel with the linear electromagnetic motor. The second ends of the linear electromagnetic motor and pneumatic cylinder and piston combination being commonly linked to a mount for the test object. A control system for the linear electromagnetic motor and pneumatic cylinder and piston combination drives the pneumatic cylinder and piston combination to support a substantial static load of the test object and the linear electromagnetic motor to impart controlled motion to the test object.

  14. Motor Importance of motor assessment in school children: analysis of the reliability of the motor development scale

    Directory of Open Access Journals (Sweden)

    Kassandra Nunes Amaro

    2010-09-01

    Full Text Available The objective of this study was to investigate the motor performance of school chil-dren aged 6 to 10 years without learning difficulties (n=101, and to analyze the reliability of the Motor Development Scale (MDS (Rosa Neto, 2002. Descriptive statistics with calculation of the mean, standard deviation, and range was used for data analysis. The internal consistency of the MDS was assessed using Cronbach’s alpha coefficient, and the correlation between variables was determined by Pearson’s linear correlation, with p<0.05. The results showed (1 that motor development was within normal limits in 96% of the children, and (2 a high correlation betwe-en chronological age and general motor age, indicating good internal consistency. These data demonstrate the logic and structured design of the MDS, confirming its reliability.

  15. Directed flux motor

    Science.gov (United States)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A directed flux motor described utilizes the directed magnetic flux of at least one magnet through ferrous material to drive different planetary gear sets to achieve capabilities in six actuated shafts that are grouped three to a side of the motor. The flux motor also utilizes an interwoven magnet configuration which reduces the overall size of the motor. The motor allows for simple changes to modify the torque to speed ratio of the gearing contained within the motor as well as simple configurations for any number of output shafts up to six. The changes allow for improved manufacturability and reliability within the design.

  16. Neuroplasticity & Motor Learning

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye

    is a measure of our ability to form and store a motor memory of the task. However, the initial memory of the task is labile and may be subject to interference. During and following motor learning plastic changes occur within the central nervous system. On one hand these changes are driven by motor practice......, on the other hand the changes underlie the formation of motor memory and the retention of improved motor performance. During motor learning changes may occur at many different levels within the central nervous system dependent on the type of task and training. Here, we demonstrate different studies from our...

  17. 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

  18. Linear Accelerator (LINAC)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Linear Accelerator A linear accelerator (LINAC) customizes high energy x-rays or ... ensured? What is this equipment used for? A linear accelerator (LINAC) is the device most commonly used ...

  19. VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR

    African Journals Online (AJOL)

    Dr Obe

    1984-09-01

    Sep 1, 1984 ... VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR by. L. A. Agu. Electrical Engineering Department. University of Nigeria, Nsukka. ABSTRACT. This paper presents the scheme for a very slow speed linear machine which uses conventional laminations and with which speeds of the same low.

  20. Implementation of feedback-linearization-modelled induction motor ...

    Indian Academy of Sciences (India)

    Moreover, the GA searchesthe optimal parameters of the simplified NFC in order to ensure the global convergence of error. The proposed simplified NFC integrates the concept of fuzzy logic and neural network structure like a conventional NFC, butit has the advantages of simplicity and improved computational efficiency ...

  1. Chronic motor tic disorder

    Science.gov (United States)

    Chronic vocal tic disorder; Tic - chronic motor tic disorder ... Chronic motor tic disorder is more common than Tourette syndrome . Chronic tics may be forms of Tourette syndrome. Tics usually start at ...

  2. Teamwork in microtubule motors.

    Science.gov (United States)

    Mallik, Roop; Rai, Arpan K; Barak, Pradeep; Rai, Ashim; Kunwar, Ambarish

    2013-11-01

    Diverse cellular processes are driven by the collective force from multiple motor proteins. Disease-causing mutations cause aberrant function of motors, but the impact is observed at a cellular level and beyond, therefore necessitating an understanding of cell mechanics at the level of motor molecules. One way to do this is by measuring the force generated by ensembles of motors in vivo at single-motor resolution. This has been possible for microtubule motor teams that transport intracellular organelles, revealing unexpected differences between collective and single-molecule function. Here we review how the biophysical properties of single motors, and differences therein, may translate into collective motor function during organelle transport and perhaps in other processes outside transport. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Fuzzy control of small servo motors

    Science.gov (United States)

    Maor, Ron; Jani, Yashvant

    1993-01-01

    To explore the benefits of fuzzy logic and understand the differences between the classical control methods and fuzzy control methods, the Togai InfraLogic applications engineering staff developed and implemented a motor control system for small servo motors. The motor assembly for testing the fuzzy and conventional controllers consist of servo motor RA13M and an encoder with a range of 4096 counts. An interface card was designed and fabricated to interface the motor assembly and encoder to an IBM PC. The fuzzy logic based motor controller was developed using the TILShell and Fuzzy C Development System on an IBM PC. A Proportional-Derivative (PD) type conventional controller was also developed and implemented in the IBM PC to compare the performance with the fuzzy controller. Test cases were defined to include step inputs of 90 and 180 degrees rotation, sine and square wave profiles in 5 to 20 hertz frequency range, as well as ramp inputs. In this paper we describe our approach to develop a fuzzy as well as PH controller, provide details of hardware set-up and test cases, and discuss the performance results. In comparison, the fuzzy logic based controller handles the non-linearities of the motor assembly very well and provides excellent control over a broad range of parameters. Fuzzy technology, as indicated by our results, possesses inherent adaptive features.

  4. Foundations of linear and generalized linear models

    CERN Document Server

    Agresti, Alan

    2015-01-01

    A valuable overview of the most important ideas and results in statistical analysis Written by a highly-experienced author, Foundations of Linear and Generalized Linear Models is a clear and comprehensive guide to the key concepts and results of linear statistical models. The book presents a broad, in-depth overview of the most commonly used statistical models by discussing the theory underlying the models, R software applications, and examples with crafted models to elucidate key ideas and promote practical model building. The book begins by illustrating the fundamentals of linear models,

  5. Non-contact estimation of the bond quality in soldered thin laminate by laser generated lamb waves; Laser reiki ramuha ni yoru handazuke sekisohaku no setsugo seijo no hisesshoku hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Kasama, H.; Futatsugi, T.; Cho, H.; Takemoto, M. [Aoyama-Gakuin University, Tokyo (Japan). Faculty of Science and Engineering

    1998-03-20

    The bond quality of a solder-bonded copper laminated plate was modeled into rigid contact (rc) and slip contact (sc) to calculate the velocity dispersion of lamb waves. The velocity dispersion of laser generated lamb waves was measured, and the bond quality or the thickness of a solder layer was evaluated by non-contact. In the model whose bond surface is rc, the velocity dispersion of lamb waves can be calculated under conditions where the stress and displacement in an interface are continuous. In the model whose bond surface is sc, it can be calculated under conditions where an interface slips freely. Weak bond indicates the velocity dispersion between rc and sc. In this model, the velocity dispersion can also be calculated by a change in the thickness of a solder layer and used for quantitative evaluation of a bond interface. A three-layer solder bond manufactured for trial could be evaluated from the velocity dispersion of laser lamb waves. At the room temperature, the change in bond quality near the solder melting point of bond laminate that was judged as rc was investigated. When the solidus temperature is exceeded, the amplitude of lamb waves and the velocity dispersion changed largely. The amplitude of lamb waves increases as the liquid phase ratio increases. The bond quality near the solder melting point can be evaluated using lamb waves. 9 refs., 10 figs., 2 tabs.

  6. Robot Arm with Tendon Connector Plate and Linear Actuator

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Bridgwater, Lyndon (Inventor); Nguyen, Vienny (Inventor); Millerman, Alexander (Inventor)

    2014-01-01

    A robotic system includes a tendon-driven end effector, a linear actuator, a flexible tendon, and a plate assembly. The linear actuator assembly has a servo motor and a drive mechanism, the latter of which translates linearly with respect to a drive axis of the servo motor in response to output torque from the servo motor. The tendon connects to the end effector and drive mechanism. The plate assembly is disposed between the linear actuator assembly and the tendon-driven end effector and includes first and second plates. The first plate has a first side that defines a boss with a center opening. The second plate defines an accurate through-slot having tendon guide channels. The first plate defines a through passage for the tendon between the center opening and a second side of the first plate. A looped end of the flexible tendon is received within the tendon guide channels.

  7. Programmable dc motor controller

    Science.gov (United States)

    Hopwood, J. E.

    1982-11-01

    A portable programmable dc motor controller, with features not available on commercial instruments was developed for controlling fixtures during welding processes. The controller can be used to drive any dc motor having tachometer feedback and motor requirements not exceeding 30 volts, 3 amperes. Among the controller's features are delayed start time, upslope time, speed, and downslope time.

  8. Electric Motor Thermal Management

    Energy Technology Data Exchange (ETDEWEB)

    Bennion, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-01

    Thermal management enables more efficient and cost-effective motors. This Annual Merit Review presentation describes the technical accomplishments and progress in electric motor thermal management R&D over the last year. This project supports a broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management.

  9. Efficiency of Brownian Motors

    OpenAIRE

    Parrondo, J. M. R.; Blanco, J. M.; Cao, F. J.; Brito, R.

    1998-01-01

    The efficiency of different types of Brownian motors is calculated analytically and numerically. We find that motors based on flashing ratchets present a,low efficiency and an unavoidable entropy production. On the other hand, a certain class of motors based on adiabatically changing potentials, named reversible ratchets, exhibit a higher efficiency and the entropy production can be arbitrarily reduced.

  10. Nonlinear Decoupling of Torque and Field Amplitude in an Induction Motor

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Vadstrup, P.; Børsting, H.

    1997-01-01

    A novel approach to control of induction motors, based on nonlinear state feedback, is presented. The resulting scheme gives a linearized input-output decoupling of the torque and the amplitude of the field. The proposed approach is used to design controllers for the field amplitude and the motor...... torque. The method is tested both by simulation and by experiments on a motor drive....

  11. Motor/generator

    Science.gov (United States)

    Hickam, Christopher Dale [Glasford, IL

    2008-05-13

    A motor/generator is provided for connecting between a transmission input shaft and an output shaft of a prime mover. The motor/generator may include a motor/generator housing, a stator mounted to the motor/generator housing, a rotor mounted at least partially within the motor/generator housing and rotatable about a rotor rotation axis, and a transmission-shaft coupler drivingly coupled to the rotor. The transmission-shaft coupler may include a clamp, which may include a base attached to the rotor and a plurality of adjustable jaws.

  12. Improved Multiple-DOF SAW Piezoelectric Motors

    Science.gov (United States)

    Bar-Cohen, Yoseph; Bao, Xiaoqi; Hull, Anthony; Wright, John

    2003-01-01

    Surface-acoustic-wave (SAW) piezoelectric motors of a proposed type would be capable of operating in multiple degrees of freedom (DOFs) simultaneously and would be amenable to integration into diverse structures and mechanisms. These motors would be compact and structurally simple and would not contain bearings or lead screws. One example of a particularly useful motor of this type would be a two-dimensional- translation stage. Another such example would be a self-actuated spherical joint that could be made to undergo controlled, simultaneous rotations about two orthogonal axes: Such a motor could serve as a mechanism for aiming an "eyeball" camera or as a compact transducer in, and an integral part of, a joint in a robot arm. The multiple-DOF SAW piezoelectric motors as now proposed would be successors to the ones reported in "Multiple-DOF Surface-Acoustic-Wave Piezoelectric Motors" (NPO-20735), NASA Tech Briefs, Vol. 24, No. 12 (December 2000), page 5b. The basic principle of operation of a multiple-DOF SAW piezoelectric motor is a straightforward extension of that of single-DOF SAW piezoelectric motors, which have been reported in several previous NASA Tech Briefs articles: For example, in the case of a linear SAW piezoelectric motor, piezoelectric transducers at opposite ends of a stator excite surface acoustic waves that travel along the surface of the stator. An object (denoted the slider) is pressed against the stator with sufficient pressure (in practice .300 MPa) that it remains in frictional contact with the stator at all times. The slider rides the crests of the waves and is thereby made to move along the surface of the stator. The direction of motion (forward or backward) is controlled by selecting the relative phase of waves generated by the two piezoelectric transducers. The speed increases with the amplitude of the waves and thus with the magnitude of the voltage applied to the transducers.

  13. 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.

  14. Synthesis of Scalar Control System of Asynchronous Motor Drive

    Directory of Open Access Journals (Sweden)

    B. I. Firago

    2007-01-01

    Full Text Available Provision of quality indices is of great importance for motor drive in the case of parametric and external disturbances. The purpose of the paper is to make synthesis of a scalar control system of asynchronous motor drive that ensures the required quality indices in the specified range of parameter changes of a linearized electric motor model. Expressions have been obtained that make it possible to estimate change limits of main linear model parametersThe paper considers a structure of a closed loop system with dynamical output feedback and its derivative. A simulation has been executed for a calculative linear system and for a system with a simulating model of an asynchronous short-circuited electric motor at various laws of frequency control.The method provides the required dynamic indices at parametric and external disturbances occurring in the limited area.

  15. Evaluation of skin firmness by the DynaSKIN, a novel non-contact compression device, and its use in revealing the efficacy of a skincare regimen featuring a novel anti-ageing ingredient, acetyl aspartic acid.

    Science.gov (United States)

    Kearney, E M; Messaraa, C; Grennan, G; Koeller, G; Mavon, A; Merinville, E

    2017-05-01

    One of the key strategies for anti-ageing in the cosmetics industry today is to target the structural changes responsible for ptosis of the skin, given its impact on age perception. Several objective and non-invasive methods are available to characterise the biomechanical properties of the skin, which are operator-dependent, involving skin contact and providing single-dimensional numerical descriptions of skin behaviour. The research introduces the DynaSKIN, a device using non-contact mechanical pressure in combination with fringe projection to quantify and visualise the skin response in 3-dimensions. We examine the age correlation of the measurements, how they compare with the Cutometer ® , and measure skin dynamics following application of a skincare regimen containing established anti-ageing ingredients. DynaSKIN and Cutometer ® measurements were made on the cheek of 80 Caucasian women (18-64 years). DynaSKIN volume, mean depth and maximum depth parameters were correlated with age and 15 Cutometer ® parameters. Subsequently, the firming efficacy of a skincare regimen featuring acetyl aspartic acid (AAA) and a peptide complex was examined in a cohort of 41 volunteers. DynaSKIN volume, mean depth and maximum depth parameters correlate with age and the Cutometer ® parameters that are associated with the skin relaxation phase (R1, R2, R4, R5, R7 and F3). Furthermore, the DynaSKIN captured significant improvements in skin firmness delivered by the skincare regimen. The DynaSKIN is a novel device capable of capturing skin biomechanics at a high level of specificity and successfully detected the firming properties of a skincare regimen. Its independent measuring principle, consumer relevance and skin firmness 3D visualisation capabilities bring objectivity and novelty to product efficacy substantiation evaluation. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Non-contact radiofrequency-induced reduction of subcutaneous abdominal fat correlates with initial cardiovascular autonomic balance and fat tissue hormones: safety analysis [v1; ref status: indexed, http://f1000r.es/4pj

    Directory of Open Access Journals (Sweden)

    Jiri Pumprla

    2015-02-01

    Full Text Available Background and objective: The non-invasive reduction of subcutaneous abdominal fat became popular in the last decade. Radiofrequency (RF, non-contact, selective-field device Vanquish® has been developed to selectively induce deep fat tissue heating to reduce waist circumference. Our analysis evaluates immediate and sustained effects of this treatment on cardiovascular autonomic function and on selected metabolic parameters. Study design/patients and methods: A retrospective proof-of-concept analysis of RF treatment effects was conducted in 20 individuals with metabolic syndrome, to reduce the subcutaneous abdominal fat. Four 30-minutes treatment sessions (manufacturer´s standard protocol were performed in 1-week intervals. Vital signs, ECG, lab screening, body composition, subcutaneous fat thickness and spectral analysis of heart rate variability (HRV have been examined before, after the 1st and 4th treatment, and at follow-up visits 1 month and 3 months after the treatment. Results: The RF treatment led to a significant reduction of abdominal circumference after the 4th session (p0.59, p<0.04. Conclusions: Our analysis shows that the selective-field RF treatment is safe and efficient for reduction of subcutaneous abdominal fat. While the treatment increases the immediate sympathetic response of the body to deep tissue heating, no sustained change in autonomic function could be recorded at 1 month follow-up. The observed correlation between initial VLF spectral power and waist circumference reduction at follow-up, as well as the association of initial adiponectin values and immediate autonomic response to the treatment might be instrumental for decisions on body contouring strategies.

  17. Nonlinear control of permanent magnet synchronous motor driving a ...

    African Journals Online (AJOL)

    This paper presents a non-linear control of permanent magnet synchronous motor (PMSM) fed by a PWM voltage source inverter. To improve the performance of this control technique, the input-output linearization technique is proposed for a system driving a mechanical load with two masses. In order to ensure a steady ...

  18. 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

  19. Slit scan radiographic system for intermediate size rocket motors

    Science.gov (United States)

    Bernardi, Richard T.; Waters, David D.

    1992-12-01

    The development of slit-scan radiography capability for the NASA Advanced Computed Tomography Inspection System (ACTIS) computed tomography (CT) scanner at MSFC is discussed. This allows for tangential case interface (bondline) inspection at 2 MeV of intermediate-size rocket motors like the Hawk. Motorized mounting fixture hardware was designed, fabricated, installed, and tested on ACTIS. The ACTIS linear array of x-ray detectors was aligned parallel to the tangent line of a horizontal Hawk motor case. A 5 mm thick x-ray fan beam was used. Slit-scan images were produced with continuous rotation of a horizontal Hawk motor. Image features along Hawk motor case interfaces were indicated. A motorized exit cone fixture for ACTIS slit-scan inspection was also provided. The results of this SBIR have shown that slit scanning is an alternative imaging technique for case interface inspection. More data is required to qualify the technique for bondline inspection.

  20. Classifying Linear Canonical Relations

    OpenAIRE

    Lorand, Jonathan

    2015-01-01

    In this Master's thesis, we consider the problem of classifying, up to conjugation by linear symplectomorphisms, linear canonical relations (lagrangian correspondences) from a finite-dimensional symplectic vector space to itself. We give an elementary introduction to the theory of linear canonical relations and present partial results toward the classification problem. This exposition should be accessible to undergraduate students with a basic familiarity with linear algebra.

  1. Linear shaped charge

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, David; Stofleth, Jerome H.; Saul, Venner W.

    2017-07-11

    Linear shaped charges are described herein. In a general embodiment, the linear shaped charge has an explosive with an elongated arrowhead-shaped profile. The linear shaped charge also has and an elongated v-shaped liner that is inset into a recess of the explosive. Another linear shaped charge includes an explosive that is shaped as a star-shaped prism. Liners are inset into crevices of the explosive, where the explosive acts as a tamper.

  2. 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

  3. Linear-Algebra Programs

    Science.gov (United States)

    Lawson, C. L.; Krogh, F. T.; Gold, S. S.; Kincaid, D. R.; Sullivan, J.; Williams, E.; Hanson, R. J.; Haskell, K.; Dongarra, J.; Moler, C. B.

    1982-01-01

    The Basic Linear Algebra Subprograms (BLAS) library is a collection of 38 FORTRAN-callable routines for performing basic operations of numerical linear algebra. BLAS library is portable and efficient source of basic operations for designers of programs involving linear algebriac computations. BLAS library is supplied in portable FORTRAN and Assembler code versions for IBM 370, UNIVAC 1100 and CDC 6000 series computers.

  4. The emotional motor system.

    Science.gov (United States)

    Holstege, G

    1992-01-01

    A large number of new descending motor pathways to caudal brainstem and spinal cord have been recognized recently. Nevertheless all the new pathways seem to belong to one of three motor systems in the central nervous system (CNS). This survey gives an overview of the pathways belonging to the so-called emotional motor system or the third motor system as defined by Holstege. The similarities and differences with the core, median and lateral paracore areas of the CNS as defined by Nieuwenhuys are discussed.

  5. Control motor brushless sensorless

    OpenAIRE

    Solchaga Pérez de Lazárraga, Gonzalo

    2015-01-01

    El proyecto consiste en la creación de un circuito capaz de controlar la velocidad de un motor brushless sensorless. Este tipo de motores eléctricos tienen como característica que no tienen escobillas para cambiar la polaridad del bobinado de su interior y tampoco precisan de un sensor que indique que ha realizado una vuelta. Los motores brushless que son controlados por este tipo de circuitos son específicos para aeronaves no tripuladas y requieren un diseño diferente a un motor brushless pe...

  6. Linear viscoelastic characterization from filament stretching rheometry

    DEFF Research Database (Denmark)

    Wingstrand, Sara Lindeblad; Alvarez, Nicolas J.; Hassager, Ole

    Traditionally, linear viscoelasticity is measured using small amplitude oscillatory shear flow. Due to experimental difficulties, shear flows are predominately confined to the linear and mildly nonlinear regime. On the other hand, extensional flows have proven more practical in measuring viscoela......Traditionally, linear viscoelasticity is measured using small amplitude oscillatory shear flow. Due to experimental difficulties, shear flows are predominately confined to the linear and mildly nonlinear regime. On the other hand, extensional flows have proven more practical in measuring...... viscoelasticity well into the nonlinear regime. Therefore at present, complete rheological characterization of a material requires two apparatuses: a shear and an extensional rheometer. This work is focused on developing a linear viscoelastic protocol for the filament stretching rheometer (FSR) in order...... to measure both linear and nonlinear dynamics on a single apparatus. With a software modification to the FSR motor control, we show that linear viscoelasticity can be measured via small amplitude squeeze flow (SASF). Squeeze flow is a combination of both shear and extensional flow applied by axially...

  7. Biological Nanomotors with a Revolution, Linear, or Rotation Motion Mechanism.

    Science.gov (United States)

    Guo, Peixuan; Noji, Hiroyuki; Yengo, Christopher M; Zhao, Zhengyi; Grainge, Ian

    2016-03-01

    The ubiquitous biological nanomotors were classified into two categories in the past: linear and rotation motors. In 2013, a third type of biomotor, revolution without rotation (http://rnanano.osu.edu/movie.html), was discovered and found to be widespread among bacteria, eukaryotic viruses, and double-stranded DNA (dsDNA) bacteriophages. This review focuses on recent findings about various aspects of motors, including chirality, stoichiometry, channel size, entropy, conformational change, and energy usage rate, in a variety of well-studied motors, including FoF1 ATPase, helicases, viral dsDNA-packaging motors, bacterial chromosome translocases, myosin, kinesin, and dynein. In particular, dsDNA translocases are used to illustrate how these features relate to the motion mechanism and how nature elegantly evolved a revolution mechanism to avoid coiling and tangling during lengthy dsDNA genome transportation in cell division. Motor chirality and channel size are two factors that distinguish rotation motors from revolution motors. Rotation motors use right-handed channels to drive the right-handed dsDNA, similar to the way a nut drives the bolt with threads in same orientation; revolution motors use left-handed motor channels to revolve the right-handed dsDNA. Rotation motors use small channels (3 nm) with room for the bolt to revolve. Binding and hydrolysis of ATP are linked to different conformational entropy changes in the motor that lead to altered affinity for the substrate and allow work to be done, for example, helicase unwinding of DNA or translocase directional movement of DNA. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  8. Non-linear oscillations

    CERN Document Server

    Hagedorn, Peter

    1982-01-01

    Thoroughly revised and updated, the second edition of this concise text provides an engineer's view of non-linear oscillations, explaining the most important phenomena and solution methods. Non-linear descriptions are important because under certain conditions there occur large deviations from the behaviors predicted by linear differential equations. In some cases, completely new phenomena arise that are not possible in purely linear systems. The theory of non-linear oscillations thus has important applications in classical mechanics, electronics, communications, biology, and many other branches of science. In addition to many other changes, this edition has a new section on bifurcation theory, including Hopf's theorem.

  9. The Emotional Motor System

    NARCIS (Netherlands)

    Holstege, G.

    1992-01-01

    A large number of new descending motor pathways to caudal brainstem and spinal cord have been recognized recently. Nevertheless all the new pathways seem to belong to one of three motor systems in the central nervous system (CNS). This survey gives an overvieuw of the pathways belonging to the

  10. THE EMOTIONAL MOTOR SYSTEM

    NARCIS (Netherlands)

    HOLSTEGE, G

    1992-01-01

    A large number of new descending motor pathways to caudal brainstem and spinal cord have been recognized recently. Nevertheless all the new pathways seem to belong to one of three motor systems in the central nervous system (CNS). This survey gives an overvieuw of the pathways belonging to the

  11. Modeling Induction Motor Imbalances

    DEFF Research Database (Denmark)

    Armah, Kabenla; Jouffroy, Jerome; Duggen, Lars

    2016-01-01

    This paper gives a study into the development of a generalized model for a three-phase induction motor that offers flexibility of simulating balanced and unbalanced parameter scenarios. By analyzing the interaction of forces within the motor, we achieve our main objective of deriving the system...

  12. Stepping motor controller

    Science.gov (United States)

    Bourret, Steven C.; Swansen, James E.

    1984-01-01

    A stepping motor is microprocessingly controlled by digital circuitry which monitors the output of a shaft encoder adjustably secured to the stepping motor and generates a subsequent stepping pulse only after the preceding step has occurred and a fixed delay has expired. The fixed delay is variable on a real-time basis to provide for smooth and controlled deceleration.

  13. 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

  14. To What Extent Can Motor Imagery Replace Motor Execution While Learning a Fine Motor Skill?

    NARCIS (Netherlands)

    Sobierajewicz, Jagna; Szarkiewicz, Sylwia; Prekoracka-Krawczyk, Anna; Jaskowski, Wojciech; van der Lubbe, Robert Henricus Johannes

    2016-01-01

    Motor imagery is generally thought to share common mechanisms with motor execution. In the present study, we examined to what extent learning a fine motor skill by motor imagery may substitute physical practice. Learning effects were assessed by manipulating the proportion of motor execution and

  15. Induction motor control

    Science.gov (United States)

    Hansen, Irving G.

    1990-01-01

    Electromechanical actuators developed to date have commonly ultilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilized induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high-frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high-frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  16. Induction motor control

    Science.gov (United States)

    Hansen, Irving G.

    1990-01-01

    Electromechanical actuators developed to date have commonly utilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilizes induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  17. Linearly constrained minimax optimization

    DEFF Research Database (Denmark)

    Madsen, Kaj; Schjær-Jacobsen, Hans

    1978-01-01

    We present an algorithm for nonlinear minimax optimization subject to linear equality and inequality constraints which requires first order partial derivatives. The algorithm is based on successive linear approximations to the functions defining the problem. The resulting linear subproblems...... are solved in the minimax sense subject to the linear constraints. This ensures a feasible-point algorithm. Further, we introduce local bounds on the solutions of the linear subproblems, the bounds being adjusted automatically, depending on the quality of the linear approximations. It is proved...... that the algorithm will always converge to the set of stationary points of the problem, a stationary point being defined in terms of the generalized gradients of the minimax objective function. It is further proved that, under mild regularity conditions, the algorithm is identical to a quadratically convergent...

  18. Basic linear algebra

    CERN Document Server

    Blyth, T S

    2002-01-01

    Basic Linear Algebra is a text for first year students leading from concrete examples to abstract theorems, via tutorial-type exercises. More exercises (of the kind a student may expect in examination papers) are grouped at the end of each section. The book covers the most important basics of any first course on linear algebra, explaining the algebra of matrices with applications to analytic geometry, systems of linear equations, difference equations and complex numbers. Linear equations are treated via Hermite normal forms which provides a successful and concrete explanation of the notion of linear independence. Another important highlight is the connection between linear mappings and matrices leading to the change of basis theorem which opens the door to the notion of similarity. This new and revised edition features additional exercises and coverage of Cramer's rule (omitted from the first edition). However, it is the new, extra chapter on computer assistance that will be of particular interest to readers:...

  19. A Recommended New Approach on Motorization Ratio Calculations of Stepper Motors

    Science.gov (United States)

    Nalbandian, Ruben; Blais, Thierry; Horth, Richard

    2014-01-01

    Stepper motors are widely used on most spacecraft mechanisms requiring repeatable and reliable performance. The unique detent torque characteristics of these type of motors makes them behave differently when subjected to low duty cycle excitations where the applied driving pulses are only energized for a fraction of the pulse duration. This phenomenon is even more pronounced in discrete permanent magnet stepper motors used in the space industry. While the inherent high detent properties of discrete permanent magnets provide desirable unpowered holding performance characteristics, it results in unique behavior especially in low duty cycles. Notably, the running torque reduces quickly to the unpowered holding torque when the duty cycle is reduced. The space industry's accepted methodology of calculating the Motorization Ratio (or Torque Margin) is more applicable to systems where the power is continuously applied to the motor coils like brushless DC motors where the cogging torques are low enough not to affect the linear performance of the motors as a function of applied current. This paper summarizes the theoretical and experimental studies performed on a number of space qualified motors under different pulse rates and duty cycles. It is the intention of this paper to introduce a new approach to calculate the Motorization Ratios for discrete permanent magnet steppers under all full and partial duty cycle regimes. The recommended approach defines two distinct relationships to calculate the Motorization Ratio for 100 percent duty cycle and partial duty cycle, when the motor detent (unpowered holding torque) is the main contributor to holding position. These two computations reflect accurately the stepper motor physical behavior as a function of the command phase (ON versus OFF times of the pulses), pointing out how the torque contributors combine. Important points highlighted under this study are the torque margin computations, in particular for well characterized

  20. STEPPING MOTOR - HYDRAULIC MOTOR SERVO DRIVES FOR ...

    African Journals Online (AJOL)

    Dr Obe

    machine tool systems wherever the existing production batch sizes and frequency of manufacture justifies it in a developing country. This is so mainly because numerically controlled (NC) ... Because the NC machine is an expensive item of equipment it is ... electric stepping motor is a very precise unit with. 10k ohms.