Sample records for stators diagnostico del

  1. DIAGNOSTICO Y PROGRAMA DE MANEJO DEL PARQUE ECOLGICO

    E-print Network

    Bor, Gil

    Secretaría de Desarrollo Social y Humano Consejo para el Desarrollo de la Región III (Centro-Occidente de urbana de la Capital del Estado de Guanajuato. Destaca por ser un elemento de gran singularidad y

  2. Segmented stator assembly

    DOEpatents

    Lokhandwalla, Murtuza; Alexander, James Pellegrino; El-Refaie, Ayman Mohamed Fawzi; Shah, Manoj Ramprasad; Quirion, Owen Scott

    2013-04-02

    An electric machine and stator assembly are provided that include a continuous stator portion having stator teeth, and a tooth tip portion including tooth tips corresponding to the stator teeth of the continuous stator portion, respectively. The tooth tip portion is mounted onto the continuous stator portion.

  3. Electrical stator

    DOEpatents

    Fanning, Alan W. (San Jose, CA); Olich, Eugene E. (Aptos, CA)

    1994-01-01

    An electrical stator of an electromagnetic pump includes first and second spaced apart coils each having input and output terminals for carrying electrical current. An elongate electrical connector extends between the first and second coils and has first and second opposite ends. The connector ends include respective slots receiving therein respective ones of the coil terminals to define respective first and second joints. Each of the joints includes a braze filler fixedly joining the connector ends to the respective coil terminals for carrying electrical current therethrough.

  4. Stator hub treatment study

    NASA Technical Reports Server (NTRS)

    Wisler, D. C.; Hilvers, D. E.

    1974-01-01

    The results of an experimental research program to investigate the potential of improving compressor stall margin by the application of hub treatment are presented. Extensive tuft probing showed that the two-stage, 0.5 radius ratio compressor selected for the test was indeed hub critical. Circumferential groove and baffled wide blade angle slot hub treatments under the stators were tested. Performance measurements were made with total and static pressure probes, wall static pressure taps, flow angle measuring instrumentation and hot film anemometers. Stator hub treatment was not found to be effective in improving compressor stall margin by delaying the point of onset of rotating stall or in modifying compressor performance for any of the configurations tested. Extensive regions of separated flow were observed on the suction surface of the stators near the hub. However, the treatment did not delay the point where flow separation in the stator hub region becomes apparent.

  5. Electromagnetic pump stator core

    DOEpatents

    Fanning, Alan W. (San Jose, CA); Olich, Eugene E. (Aptos, CA); Dahl, Leslie R. (Livermore, CA)

    1995-01-01

    A stator core for supporting an electrical coil includes a plurality of groups of circumferentially abutting flat laminations which collectively form a bore and perimeter. A plurality of wedges are interposed between the groups, with each wedge having an inner edge and a thicker outer edge. The wedge outer edges abut adjacent ones of the groups to provide a continuous path around the perimeter.

  6. Stator winding monitoring

    Microsoft Academic Search

    G. Stone; J. Kapler

    1998-01-01

    Partial discharge tests can determine which motor and generator stator windings are experiencing insulation problems. A deteriorated winding has a PD activity which can be 30 times or more higher than a winding in good condition. This great difference in PD activity enables even nonspecialized maintenance personnel to identify the few motors or generators in a company which need further

  7. Banded electromagnetic stator core

    DOEpatents

    Fanning, Alan W. (San Jose, CA); Gonzales, Aaron A. (San Jose, CA); Patel, Mahadeo R. (San Jose, CA); Olich, Eugene E. (Aptos, CA)

    1996-01-01

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

  8. Banded electromagnetic stator core

    DOEpatents

    Fanning, Alan W. (San Jose, CA); Gonzales, Aaron A. (San Jose, CA); Patel, Mahadeo R. (San Jose, CA); Olich, Eugene E. (Aptos, CA)

    1994-01-01

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

  9. Banded electromagnetic stator core

    DOEpatents

    Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

    1994-04-05

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figures.

  10. A stator flux oriented induction machine drive

    Microsoft Academic Search

    Xingyi Xu; Rik De Doncker; D. W. Novotny

    1988-01-01

    The sensitivity of the parameters of a rotor-flux-oriented system using rotor flux estimation is discussed, and a stator-flux-oriented scheme is developed. Since the estimation of the stator flux is independent of the leakage, the steady-state performance of the stator-flux-oriented system is insensitive to the leakage inductance. A decoupler is designed to minimize the coupling in the stator-flux reference frame, improving

  11. Analytical and experimental investigation of stator endwall contouring in a small axial-flow turbine. 1: Stator performance

    NASA Technical Reports Server (NTRS)

    Haas, J. E.

    1982-01-01

    Three stator configurations were studied to determine the effect of stator outer endwall contouring on stator performance. One configuration was a cylindrical stator design. One contoured stator configuration had an S-shaped outer endwall, the other had a conical-convergent outer endwall. The experimental investigation consisted of annular surveys of stator exit total pressure and flow angle for each stator configuration over a range of stator pressure ratio. Radial variations in stator loss and aftermixed flow conditions were obtained when these data were compared with the analytical results to assess the validity of the analysis, good agreement was found.

  12. Dual stator winding induction machine drive

    Microsoft Academic Search

    Alfredo R. Muñoz; Thomas A. Lipo

    2000-01-01

    A new dual stator winding induction machine drive is described in this paper. The proposed induction machine consists of a standard squirrel-cage rotor and a stator with two separate windings wound for a dissimilar number of poles. Each stator winding is fed from an independent variable-frequency variable-voltage inverter. The proposed drive offers such advantages as speed sensorless operation, better reliability,

  13. The evaluation of ceramic turbine stators

    NASA Technical Reports Server (NTRS)

    Fisher, E. A.; Trela, W.

    1979-01-01

    A ceramic turbine stator evaluation program administered by the NASA Lewis Research Center and supported by the Department of Energy is outlined. The objectives of the program are to evaluate the durability of ceramic stators over a highly dynamic automotive gas turbine duty cycle and to assess the capability of current ceramic design methodology to predict the durability of the stators over the selected duty cycle for times in excess of 200 hours. The program also provides an assessment of the ability of the ceramic industry to fabricate complex geometry monolithic stators by near-net-shape forming processes. A summary of results obtained to date is presented and future plans are discussed.

  14. Study of controlled diffusion stator blading

    NASA Technical Reports Server (NTRS)

    Behlke, R. F.; Brooky, J. D.; Canal, E.

    1983-01-01

    Tests were conducted on a high tip speed, highly loaded front compressor stage having low aspect ratio rotor and stator airfoils. The stator airfoils were designed by the controlled diffusion procedure recently developed by P&WA for designing transonic cascade airfoils. The rotor blades consisted of multiple-circular-arc airfoil sections. The stage had a tip speed of 442 m/sec (1450 ft/sec), a hub/tip ratio of 0.597, a rotor aspect ratio of 1.3, and a stator aspect ratio of 1.45. At design speed the rotor-stator stage achieved an adiabatic efficiency of 89.1% at design flow and pressure ratio. Surge margin was 14%. The stage efficiency exceeded the design goal by 0.6 percentage points. The rotor efficiency was 92.4%, exceeding design by 0.3 percentage points. The controlled diffusion stator demonstrated a lower minimum loss over the multiple-circular-arc stator from the root to 70 percent span. A surge diffusion factor of 0.72 was reached at both the rotor tip and the stator root. The NAS3-22008 program demonstrated its intent: high efficiency and loading levels with low aspect ratio blades and the controlled diffusion stator in the unfavorable front stage environment.

  15. Stator well flows in axial compressors

    Microsoft Academic Search

    H. K. Öztürk; A. B. Turner; P. R. N. Childs; F. J. Bayley

    2000-01-01

    This paper reports a study of the flow conditions in spaces often found beneath the stationary blades of modern compressors – stator wells. The design of the stator wells in a modern high-pressure turbofan can be a limiting factor. This study shows good comparison with existing experimental data upon the pressures and velocities in related geometries. The deleterious effects upon

  16. Fundamental Investigation of Circumferentially Varying Stator Cascades

    NASA Astrophysics Data System (ADS)

    Farnsworth, John A. N.

    2011-12-01

    The fundamentals of circumferentially varying stator cascades and their interactions with a downstream fixed pitch propeller were investigated experimentally utilizing multiple measurement techniques. The flow physics associated with the isolated circumferentially varying, or cyclic, stator cascade was studied in a wind tunnel environment through string tuft flow visualization, 2-D PIV, Stereoscopic PIV, and static surface pressure measurements. The coupled wake physics of the cyclic stator cascade with propeller were then investigated in a water tunnel using Stereo PIV. Finally, the global performance of components and the coupled system were quantified through force and moment measurements on the model in the water tunnel. A cyclic distribution of the stators' deflections resulted in non-axisymmetric distributions of the surface pressure and the flow field downstream of the stator array. In the model near wake the flow field is associated with secondary flow patterns in the form of coherent streamwise vortical structures that can be described by potential flow mechanisms. The collective pitch distribution of the stators produces a flow field that resembles a potential Rankine vortex, whereas the cyclic pitch distribution generates a flow pattern that can be described by a potential vortex pair in a cross flow. The stator distribution alone produces a significant side force that increases linearly with stator pitch amplitude. When a propeller is incorporated downstream from the cyclic cascade the side force from the stator cascade is reduced, but a small vertical force and pitching moment are created. The generation of these secondary forces and moments can be related to the redistribution of the tangential flow from the cyclic cascade into the axial direction by the retreating and advancing blade states of the fixed pitch propeller.

  17. Design and performance of controlled-diffusion stator compared with original double-circular-arc stator

    NASA Technical Reports Server (NTRS)

    Gelder, Thomas F.; Schmidt, James F.; Suder, Kenneth L.; Hathaway, Michael D.

    1987-01-01

    The capabilities of two stators, one with controlled-diffusion (CD) blade sections and one with double-circular-arc (DCA) blade sections, were compared. A CD stator was designed and tested that had the same chord length but half the blades of the DCA stator. The same fan rotor (tip speed, 429 m/sec; pressure ratio, 1.65) was used with each stator row. The design and analysis system is briefly described. The overall stage and rotor performances with each stator are compared, as are selected blade element data. The minimum overall efficiency decrement across the stator was approximately 1 percentage point greater with the CD balde sections than with the DCA blade sections.

  18. Deterioration of stator winding insulation by vibration sparking

    Microsoft Academic Search

    G. C. Stone

    2008-01-01

    Since the introduction of epoxy mica stator windings, some turbine generator stator windings have apparently failed due to a mechanism variously referred to as spark erosion or vibration sparking. The mechanism can produce relatively intense sparking between the surface of the stator bar and the core. The intensity of the sparking is such that it may erode the groundwall insulation

  19. Diagnostico de Prenez en Ganado Vacuno. 

    E-print Network

    Sorensen, A. M. Jr.; Beverly, J. R.; Arias, A. A.

    1975-01-01

    del Texas Agricultural Extension Service cle su contlaclo. Para c:~lcul:~r 10s costos de operacitin, tome un precio especifico de 27 centavos y coloque el punto en el cual ni g;ma ni pierde dinero (I~reak-even point) con ese precio en la tal~la 1.... Si 1~1ce esto, se requiere destetar un 90 poi- ciento de 10s I,ecerros que pesan 400 1il11-as p:~ra Ilegar a1 punto en el cual ni gana ni pierde dinero. Si sGlo desteta un 60 por ciento de 10s I~ecerros que pesan 400 libras, entonces el costo...

  20. Turbine rotor\\/stator flowfield analysis

    Microsoft Academic Search

    1989-01-01

    A numerical study of the unsteady aerodynamic and thermal environment associated with axial turbine stages is presented. Computations are performed using a modification of the ROTOR1 rotor\\/stator interaction code. Two different turbine states are analyzed: the first state of the United Technologies Research Center large scale rotating rig and the first state of the Space Shuttle main engine (SSME) high

  1. Development of a generator stator insulation system

    NASA Astrophysics Data System (ADS)

    Buritz, R. S.

    1983-04-01

    The insulation of stator windings in generators is an old technology, dating to the turn of the century with kraft paper insulated, oil filled cables. Recently, two new classes of machines requiring much more advanced techniques of insulation have emerged. These generators are designed for relatively short duty in situations where light weight and small size are crucial to the overall mission, and mobility is a must. One class of machines uses superconducting windings to achieve small size. The other class consists of conventional generators designed to have extremely high power densities and specific powers. These machines represent a considerable engineering achievement, being significantly smaller than any previous generator. In one of these generators, manufactured by Bendix, substantial problems have been encountered in the stator winding insulation, because of the high fields dictated by the extremely high power density. This report presents the Hughes Aircraft Company approach and solution to these problems.

  2. Reconstruction of the Switched Reluctance Motor Stator

    NASA Astrophysics Data System (ADS)

    El-Kharashi, Eyhab; Hassanien, Hany M.

    2012-01-01

    The paper re-designs the conventional 6/8 switched reluctance motor (SRM) by a particular way to minimize the losses. The flux loops are shortened by making each two stator teeth incorporated in one magnetic circuit only. Subsequently the flux does not cross in some iron parts of the stator core backs. These unused iron sections are taken off consequently the iron losses decreased. Now the stator consists of three separated sections and they are fixed inside non-magnetic cylinder. The copper losses also are decreased because less copper windings are used to produce the same amount of the output torque as the flux paths become short then the flux density increases. The analysis and comparison of the 6/8 SRM before and after the re-design process are presented. A m files Matlab software is used to simulate the dynamic performance. Then the paper proceeds to examine different control techniques to the new design. The hysteresis and PI controllers are used as classical method to control the SRM. Then the artificial neural network (ANN) is used to test the new control techniques.

  3. Small axial turbine stator technology program

    NASA Technical Reports Server (NTRS)

    Brockett, W.; Kozak, A.

    1982-01-01

    An experimental investigation was conducted to determine the effects of surface finish, fillet radius, inlet boundary layer thickness, and free-stream inlet turbulence level on the aerodynamic performance of a small axial flow turbine stator. The principal objective of this program was to help understand why large turbine efficiency is not maintained when a large turbine is scaled to a smaller size. The stator used in this program as a one-sixth scale of a 762 mm (30 in.) diameter stator design with 50 vanes having a vane height of 17 mm (0.666 in.) and an aspect ratio of 1.77. A comprehensive overall test matrix was used to provide a complete engineering understanding of the effects of each variable over the full range of all the other variables. The range of each variable investigated was as follows: surface finish 0.1 micro (4 micro in.) to 2.4 micro (95 micro in.); boundary layer thickness 2 to 25 percent of channel height at each wall; fillet radius 0 mm (0 in.) to 1.0 mm (.040 in.) and turbulence 2 to 12 percent.

  4. Rotor wake\\/stator interaction noise-predictions versus data

    Microsoft Academic Search

    D. A. Topol

    1990-01-01

    A rotor wake\\/stator interaction noise prediction method is presented and evaluated with fan rig and full-scale engine data. The noise prediction method uses a two-dimensional (2D) semi-empirical wake model and an analytical stator response function and noise calculation. The stator response function is a 2D strip theory which is linked to a noise calculation formulated in a constant area annular

  5. Noise of fan designed to reduce stator lift fluctuations

    NASA Technical Reports Server (NTRS)

    Dittmar, J. H.; Woodward, R. P.; Stakolich, E. G.

    1977-01-01

    An existing fan stage was redesigned to reduce stator lift fluctuations and was acoustically tested at three nozzle sizes for reduced noise generation. The lift fluctuations on the stator were reduced by increasing the stator cord, adjusting incidence angles, and adjusting the rotor velocity diagrams. Broadband noise levels were signficantly reduced in the middle to high frequencies. Blade passage tone sound power was not lessened, but decreases in the harmonics were observed. Aerodynamic improvements in both performance and efficiency were obtained.

  6. Sequential cooling insert for turbine stator vane

    DOEpatents

    Jones, Russell B; Krueger, Judson J; Plank, William L

    2014-04-01

    A sequential impingement cooling insert for a turbine stator vane that forms a double impingement for the pressure and suction sides of the vane or a triple impingement. The insert is formed from a sheet metal formed in a zigzag shape that forms a series of alternating impingement cooling channels with return air channels, where pressure side and suction side impingement cooling plates are secured over the zigzag shaped main piece. Another embodiment includes the insert formed from one or two blocks of material in which the impingement channels and return air channels are machined into each block.

  7. Stator performance and unsteady loading in transonic compressor stages

    SciTech Connect

    Durali, M.; Kerrebrock, J.L. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

    1998-04-01

    The structure and behavior of wakes from a transonic compressor rotor and their effect on the loading and performance of the downstream stator have been investigated experimentally. The rotor was 23.25 inches in diameter with a measured tip Mach number of 1.23 and a pressure ratio of 1.66. Time and space-resolved measurements have been completed of the rotor and stator outflow, as well of the pressure distribution on the surface of the stator blades. It was found that the wakes from this rotor have large flow angle and flow Mach number variations from the mean flow, significant pressure fluctuations, and a large degree of variation from hub to tip. There was a significant total pressure defect and practically no static pressure variation associated with the stator wakes. Wakes from the rotor exist nearly undiminished in the exit flow of the stator and decay in the annular duct behind the stator. The pressure at all points along the chord over each of the stator blades` surfaces fluctuated nearly in phase in response to the rotor wakes, that is the unsteady chordwise pressure distribution is determined mainly by the change in angle of incidence to the blade and not by the local velocity fluctuations within the passage. The unsteady forces on the stator blades, induced by the rotor wakes, were as high as 25% of the steady forces, and lagged the incidence of the wakes on the leading edge by approximately 180 deg at most radii.

  8. Vibration Sparking and Slot Discharge in Stator Windings

    Microsoft Academic Search

    G. C. Stone; C. Maughan

    2008-01-01

    In the late 1980s and again in the past few years, some turbine generator stator windings have apparently failed due to a mechanism variously referred to as spark erosion or vibration sparking. The mechanism can produce relatively intense sparking between the surface of the stator bar and the core. The intensity of the sparking is such that it may erode

  9. Gearbox Monitoring Using Induction Machine Stator Current Analysis

    Microsoft Academic Search

    Shahin Hedayati Kia; Humberto Henao; Gerard-Andre Capolino

    2007-01-01

    The aim of this paper is the monitoring of a gearbox by using the stator current signature analysis in the driving induction machines. The detection of mechanical faults using the vibration signal analysis has been well studied before. Recently, some works have been performed in order to observe the vibration components of the mechanical part in the stator current spectrum

  10. Numerical modelling of a supersonic axial turbine stator

    NASA Astrophysics Data System (ADS)

    Grönman, Aki; Turunen-Saaresti, Teemu; Jaatinen, Ahti; Backman, Jari

    2010-06-01

    In order to improve the turbocharging process, a supersonic axial turbine stator was modelled numerically with a pulsatile inlet mass flow. The main objectives of the study were to find out how pulsation affects the flow field and the performance of the stator. At the beginning of the study, a supersonic turbine stator was modelled using three different techniques: quasi-steady, time-accurate with constant boundary conditions and time-accurate with a pulsatile inlet mass flow. The time-averaged and quasi-steady flow fields and performance were compared, and the flow field and stator performance with a pulsatile inlet mass flow was studied in detail at different time-steps. A hysteresis-like behaviour was captured when the total-to-static pressure ratio and efficiency were plotted as a function of the inlet mass flow over one pulse period. The total-to-static pressure ratio and efficiency followed the sinusoidal shape of the inlet flow as a function of time. It was also concluded that the stator efficiency decreases downstream from the stator trailing edge and the amplitude of the pulsating mass flow is decreased at the stator throat.

  11. Status of the Ford program to evaluate ceramics for stator applications in automotive gas turbine engines

    NASA Technical Reports Server (NTRS)

    Trela, W.

    1980-01-01

    The paper reviews the progress of the major technical tasks of the DOE/NASA/Ford program Evaluation of Ceramics for Stator Applications in Automotive Gas Turbine Engines: reliability prediction, stator fabrication, material characterization, and stator evaluation. A fast fracture reliability model was prepared for a one-piece ceramic stator. Periodic inspection results are presented.

  12. Evaluation of Steam Turbines Triangular Tooth on Stator Labyrinth Seal

    E-print Network

    Tanvir, Hossain Ahmed

    2012-07-16

    of turbomachinery is attained. Performance parameters such as carryover coefficient, discharge coefficient were evaluated for a see through triangular tooth on stator labyrinth seal. This computational study investigates how flow conditions and seal parameter...

  13. Stator design of a new type of spherical piezoelectric motor.

    PubMed

    Ting, Yung; Tsai, Yu-Ren; Hou, Bing-Kuan; Lin, Shuo-Chun; Lu, Cheng-Chin

    2010-10-01

    The stator design of a new type of spherical motor driven by piezoelectric actuators is developed. A curved piezoelectric actuator is designed to attach to the spherical surface. A series of the curved piezoelectric actuators is laid in a line around a spherical surface. By applying an appropriate voltage signal with phase difference on neighboring actuators, a traveling wave is generated on the hemispherical shell. Each set of curved piezoelectric actuators is designed to provide motion with a single degree-of-freedom (DOF). With two or three sets of the piezoelectric actuators constructed to be mutually perpendicular, the motor can provide 2-DOF or 3-DOF motion. Stator design and analysis and experiment for the 1-, 2-, and 3-DOF conditions are presented in this article. Analytical calculation and experiment results of several fundamental characteristics of the stator are in good agreement. Performance evaluation of rotation speed and torque of the stator and some implementation problems are also addressed. PMID:20889421

  14. Effects of reset stators and a rotating, grooved stator hub on performance of a 1.92-pressure-ratio compressor stage

    NASA Technical Reports Server (NTRS)

    Lewis, G. W., Jr.; Urasek, D. C.; Reid, L.

    1977-01-01

    The overall performance and blade-element performance of a transonic fan stage are presented for two modified test configurations and are compared with the unmodified stage. Tests were conducted with reset stators 2 deg open and reset stators with a rotating grooved stator hub. Detailed radial and circumferential (behind stator) surveys of the flow conditions were made over the stable operating range at rotative speeds of 70, 90, and 100 percent of design speed. Reset stator blade tests indicated a small increase in stage efficiency, pressure ratio, and maximum weight flow at each speed. Performance with reset stators and a rotating, grooved stator hub resulted in an additional increase in stage efficiency and pressure ratio at all speeds. The rotating grooved stator hub reduced hub losses considerably.

  15. Measurements of a stator-induced circumferentially varying flow

    NASA Astrophysics Data System (ADS)

    Farnsworth, John; Amitay, Michael; Beal, David; Huyer, Stephen A.

    2011-08-01

    The flow physics associated with the generation of both axisymmetric and non-axisymmetric swirl by various deflection patterns of a stator array was investigated experimentally through surface pressure and Stereoscopic Particle Image Velocimetry measurements. A three-dimensional rendering technique was developed to reconstruct the flow field around the model and in its wake. The three-dimensional fluid volume was reconstructed from multiple two-dimensional measurement planes. A cyclic distribution of the stators' deflections resulted in non-axisymmetric distributions of the surface pressure and the flow field downstream of the stator array. The addition of a shroud had an amplifying effect: accelerating the flow through the stator array while reducing the non-uniform tangential velocity component generated by the stators. In the model near wake the flow field is associated with secondary flow patterns in the form of coherent streamwise vortical structures that can be described by potential flow mechanisms. The collective pitch distribution of the stators produces a flow field that resembles a potential Rankine vortex, whereas the cyclic pitch distribution generates a flow pattern that can be described by a potential vortex pair in a cross-flow.

  16. Stator flux based space-vector modulation and closed loop control of the stator flux vector in overmodulation into six-step mode

    Microsoft Academic Search

    Anshuman Tripathi; Ashwin M. Khambadkone; Sanjib K. Panda

    2004-01-01

    This paper presents closed loop control of stator flux vector in a wide operating range that can be used in torque control. A predictive control achieves zero phase error at constant switching frequency. Space vector modulation based on stator flux error vector is used to achieve control of stator flux over the entire range including overmodulation and six-step. During dynamics

  17. Impulsive Injection for Compressor Stator Separation Control

    NASA Technical Reports Server (NTRS)

    Culley, Dennis E.; Braunscheidel, Edward P.; Bright, Michelle M.

    2005-01-01

    Flow control using impulsive injection from the suction surface of a stator vane has been applied in a low speed axial compressor. Impulsive injection is shown to significantly reduce separation relative to steady injection for vanes that were induced to separate by an increase in vane stagger angle of 4 degrees. Injected flow was applied to the airfoil suction surface using spanwise slots pitched in the streamwise direction. Injection was limited to the near-hub region, from 10 to 36 percent of span, to affect the dominant loss due to hub leakage flow. Actuation was provided externally using high-speed solenoid valves closely coupled to the vane tip. Variations in injected mass, frequency, and duty cycle are explored. The local corrected total pressure loss across the vane at the lower span region was reduced by over 20 percent. Additionally, low momentum fluid migrating from the hub region toward the tip was effectively suppressed resulting in an overall benefit which reduced corrected area averaged loss through the passage by 4 percent. The injection mass fraction used for impulsive actuation was typically less than 0.1 percent of the compressor through flow.

  18. Frecuencia de los defectos del tubo neural en Asturias: impacto del diagnostico prenatal

    Microsoft Academic Search

    Enrique GarciaL; Cristina Rodriguez Dehli; Fernando Ariza Hevia; Adela Rodriguez Fernandez; Joaquin Fernandez Toral; Isolina Riano Galan; Carmen Mosquera Tenreiro; Hospital V. Alvarez-Buylla

    Objective: To describe the frequency and prevalence trend for neural tube defects (NTD) (anencephaly, spina bifida and encephalocele) in Asturias (Spain), as well as the impact of prenatal diagnosis programs. Methods: All cases of NTD in births and induced abortions were studied, using data from the Registry of Congenital Defects of Asturias for 1990-2004. Total and birth prevalence rates were

  19. INCUBACION ANAEROBICA DEL SUELO COMO DIAGNOSTICO DE LA RESPUESTA A NITROGENO DEL MAIZ BAJO SIEMBRA DIRECTA

    Microsoft Academic Search

    PA CALVIÑO; HE ECHEVERRÍA

    -1 then the yield increment = 72,5 - 1,38 Nan, if Nan > 48.mg kg -1 the yield increment = 6 %). Nan was related with the time (years) since the last pasture (r 2 = 0.39). These results suggest that Nan probably is associated with light carbon fractions and can be used to explain the response of maize to

  20. A comparison of experimental and theoretical results for labyrinth gas seals with honeycomb stators 

    E-print Network

    Hawkins, Lawrence Allen

    1988-01-01

    are compared to the coefficients of a labyrinth-rotor/smooth-stator seal having the same geometry. The coefficients are also compared to analytical results from a two-control-volume compressible ffow model. The experimental results show that the honeycomb... stator conffguration is more stable than the smooth stator conffguration at low rotor speeds. At high rotor speeds and low clearance, the smooth stator seal is more stable. The theoretical model predicts the cross- coupled stiffness of the honeycomb...

  1. Magnetic equivalent circuit modeling of induction machines under stator and rotor fault conditions

    Microsoft Academic Search

    Gennadi Y. Sizov; Chia-Chou Yeh; Nabeel A. O. Demerdash

    2009-01-01

    In this paper, stator and rotor failures in squirrel-cage induction machines are modeled using the magnetic equivalent circuit (MEC) approach. Failures associated with stator winding and rotor cage are considered. More specifically, stator inter-turn short circuit and broken rotor bar failures are modeled. When compared to conventional modeling techniques, the MEC modeling approach offers two main advantages: 1) relatively high

  2. Stator current-based sensorless vibration monitoring of induction motors

    Microsoft Academic Search

    Caryn M. Riley; Brian K. Lin; Thomas G. Habetler; Gerald B. Kliman

    1997-01-01

    This paper presents an initial study into the relationship between vibration and current harmonics of electric motors, including the effect of externally induced vibrations. This relationship was investigated experimentally on both new motors, on a vibration stand and on a motor with berating wear. Both theory and experimental results show that a change in the RMS value of the stator

  3. Low power stator core fault testing using EL CID

    Microsoft Academic Search

    D. B. Paley

    1998-01-01

    Generator stators are made from thin laminations with interlaminar insulation, defects in which permit damaging currents to flow. Traditional test methods require a substantial supply to excite the core at rated magnetic flux, temperature rises due to faults being detected by various means. The test is performed with the rotor removed and requires significant time and labour. The alternative low

  4. Stator fault estimation in induction motors using particle swarm optimization

    Microsoft Academic Search

    Hassan M. Emara; M. E. Ammar; A. Bahgat; H. T. Dorrah

    2003-01-01

    The use of induction motors is extensive in industry. The working conditions of these motors make them subject to many faults. These faults must be detected in an early stage before they lead to catastrophic failures. This paper presents a scheme for detecting inter-turn faults in the stator windings of induction motors and estimating the fault severity. Detection of incipient

  5. Electromagnetic pump stator frame having power crossover struts

    DOEpatents

    Fanning, Alan W. (San Jose, CA); Olich, Eugene E. (Aptos, CA)

    1995-01-01

    A stator frame for an electromagnetic pump includes a casing joined to a hub by a plurality of circumferentially spaced apart struts. At least one electrically insulated power crossover lead extends through the hub, through a crossover one of the struts, and through the casing for carrying electrical current therethrough.

  6. Paralleling the stator coils in permanent magnet machines

    Microsoft Academic Search

    Mohammad S. Islam; Sayeed Mir; Tomy Sebastian

    2005-01-01

    As low voltage machines require smaller number of turns per phase compared to higher voltage machines, it is normal to connect the various stator phase coils in parallel to form the phase winding. The placement of various coil sides in the slot and the difference in the field produced by different poles of the rotor magnet can influence the induced

  7. Advancements in partial discharge analysis to diagnose stator winding problems

    Microsoft Academic Search

    V. Warren; G. C. Stone; M. Fenger

    2000-01-01

    On-line partial discharge (PD) testing has been used for over 50 years to assess the condition of motor and generator stator winding insulation systems. In the past decade, advanced hardware and software have enabled superior methods of converting the PD data into practical information about the relative condition of the insulation, as well as determining the root causes of any

  8. Aeropropulsion Technology (APT). Task 23 - Stator Seal Cavity Flow Investigation

    NASA Technical Reports Server (NTRS)

    Heidegger, N. J.; Hall, E. J.; Delaney, R. A.

    1996-01-01

    The focus of NASA Contract NAS3-25950 Task 23 was to numerically investigate the flow through an axial compressor inner-banded stator seal cavity. The Allison/NASA developed ADPAC code was used to obtain all flow predictions. Flow through a labyrinth stator seal cavity of a high-speed compressor was modeled by coupling the cavity flow path and the main flow path of the compressor. A grid resolution study was performed to guarantee adequate grid spacing was used. Both unsteady rotor-stator-rotor interactions and steady-state isolated blade calculations were performed with and without the seal cavity present. A parameterized seal cavity study of the high-speed stator seal cavity collected a series of solutions for geometric variations. The parameter list included seal tooth gap, cavity depth, wheel speed, radial mismatch of hub flowpath, axial trench gap, hub corner treatments, and land edge treatments. Solution data presented includes radial and pitchwise distributions of flow variables and particle traces describing the flow character.

  9. Transient model for induction machines with stator winding turn faults

    Microsoft Academic Search

    Rangarajan M. Tallam; Thomas G. Habetler; Ronald G. Harley

    2002-01-01

    A transient model for an induction machine with stator winding turn faults is derived using reference frame transformation theory. A state-space representation of the dynamic equations, suitable for digital simulation is provided. Steady-state equivalent circuits are derived, from which the sequence components of the line currents can be estimated as a function of fault severity. Experimental results are provided to

  10. Nickel base alloy. [for gas turbine engine stator vanes

    NASA Technical Reports Server (NTRS)

    Freche, J. C.; Waters, W. J. (inventors)

    1977-01-01

    A nickel base superalloy for use at temperatures of 2000 F (1095 C) to 2200 F (1205 C) was developed for use as stator vane material in advanced gas turbine engines. The alloy has a nominal composition in weight percent of 16 tungsten, 7 aluminum, 1 molybdenum, 2 columbium, 0.3 zirconium, 0.2 carbon and the balance nickel.

  11. Stator Loading Measurements Behind a Fan With Trailing Edge Blowing

    NASA Technical Reports Server (NTRS)

    Waitz, Ian A.

    2000-01-01

    The problem of aircraft noise pollution around airports has become increasingly important as those areas have become more densely populated. Currently, the removal of older noisier aircraft from operation is reducing noise levels around airports; however, with air traffic projected to increase by about 5% over the next decade the number of commercial aircraft operating in the world is expected to be about 17,700 by the year 2007. To keep noise levels around airports from increasing as a result of traffic increases, it is important to investigate new methods of noise reduction. The objective of this work is to provide a better understanding of the effects that trailing edge blowing has on stator unsteady loading. This is done by presenting flowfield and stator loading data from experiments conducted with and without trailing edge blowing.

  12. Rotor to stator contacts in turbomachines. Review and application

    NASA Astrophysics Data System (ADS)

    Jacquet-Richardet, G.; Torkhani, M.; Cartraud, P.; Thouverez, F.; Nouri Baranger, T.; Herran, M.; Gibert, C.; Baguet, S.; Almeida, P.; Peletan, L.

    2013-11-01

    The safety of turbomachines requires controlling the risks caused by contacts occurring between fixed and rotating parts. Undesirable phenomena induced by bladed wheel/casing interactions are caused by the forced excitation of the natural modes of a blade leading to its damage or by potentially dangerous couplings between the modes of the casing and those of the wheel. Rotor-stator contacts may also lead to various types of dangerous behavior, including the well known configurations of dry whirl and dry whip. The paper proposes a large-scale literature review and examines existing numerical models and experimental setups used for highlighting the phenomenology involved in different rotor to stator contacts configurations. It confirms the great complexity of the problems which, by nature, are considerably nonlinear and involve multiphysics and multiscale coupled behaviors.

  13. Rotor and stator assembly configured as an aspirating face seal

    NASA Technical Reports Server (NTRS)

    Turnquist, Norman Arnold (Inventor); Bagepalli, Bharat Sampathkumaran (Inventor); Reluzco, George (Inventor); Tseng, Wu-Yang (Inventor)

    1999-01-01

    A rotor and stator assembly having a rotor and a stator with opposing surfaces defining an air bearing and an air dam of an aspirating face seal. In a first embodiment, the air bearing and the air dam are axially offset. In a second embodiment, the rotor has an axially extending protuberance located radially between the air bearing and the air dam. The axial offset and the protuberance each act to divert the air flow (e.g., compressed gas or combustion gases in a gas turbine or steam in a steam turbine) in a direction transverse to the air flow direction through the air bearing and the air dam, thus isolating the air flows from the air bearing and the air dam which improves seal performance.

  14. Analyzing Flow Fields in Axial-Compressor Rotors and Stators

    NASA Technical Reports Server (NTRS)

    Thompkins, W. J., Jr.

    1984-01-01

    Computer program, BLADE3D, developed for analysis of inviscid threedimensional flow fields in single blade passage of axial-compressor rotor or stator. Applicable to arbitrary axial-compressor hub, tip, and blade geometries, including blades with part-span dampers. Also used for axial turbines but with lowered resolution of flows about blunt leading and trailing edges. Analysis method valid for subsonic, transonic and supersonic flows, including choked flows.

  15. High voltage stator for a flywheel energy storage system

    Microsoft Academic Search

    T. A. Aanstoos; J. P. Kajs; W. G. Brinkman; H. P. Liu; A. Ouroua; R. J. Hayes; C. Hearn; J. Sarjeant; H. Gill

    2001-01-01

    The University of Texas at Austin Center for Electromechanics (UT-CEM) has designed and conducted component test\\/development for a flywheel energy storage system for pulsed loads and mobility load leveling in a tactical vehicle. Performance goals of this machine dictate that the stator windings will see continuous voltages of 6.7 kV and spikes to 10 kV. To manage the thermal loads

  16. Influence of vane sweep on rotor-stator interaction noise

    NASA Astrophysics Data System (ADS)

    Envia, Edmane; Kerschen, Edward J.

    1990-12-01

    The influence of vane sweep in rotor-stator interaction noise is investigated. In an analytical approach, the interaction of a convected gust representing the rotor viscous wake, with a cascade of cascade of finite span swept airfoils, representing the stator, is analyzed. The analysis is based on the solution of the exact linearized equations of motion. High frequency convected gusts for which noise generation is concentrated near the leading edge of airfoils is considered. In a preliminary study, the problem of an isolated finite span swept airfoil interacting with a convected gust is analyzed. Results indicate that sweep can substantially reduce the farfield noise levels for a single airfoil. Using the single airfoil model, an approximate solution to the problem of noise radiation from a cascade of finite span swept airfoils interacting with a convected gust is derived. A parametric study of noise generated by gust cascade interaction is carried out to assess the effectiveness of vane sweep in reducing rotor-stator interaction noise. The results show that sweep is beneficial in reducing noise levels. Rotor wake twist or circumferential lean substantially influences the effectiveness of vane sweep. The orientation of vane sweep must be chosen to enhance the natural phase lag caused by wake lean, in which case rather small sweep angles substantially reduce the noise levels.

  17. Influence of vane sweep on rotor-stator interaction noise

    NASA Technical Reports Server (NTRS)

    Envia, Edmane; Kerschen, Edward J.

    1990-01-01

    The influence of vane sweep in rotor-stator interaction noise is investigated. In an analytical approach, the interaction of a convected gust representing the rotor viscous wake, with a cascade of cascade of finite span swept airfoils, representing the stator, is analyzed. The analysis is based on the solution of the exact linearized equations of motion. High frequency convected gusts for which noise generation is concentrated near the leading edge of airfoils is considered. In a preliminary study, the problem of an isolated finite span swept airfoil interacting with a convected gust is analyzed. Results indicate that sweep can substantially reduce the farfield noise levels for a single airfoil. Using the single airfoil model, an approximate solution to the problem of noise radiation from a cascade of finite span swept airfoils interacting with a convected gust is derived. A parametric study of noise generated by gust cascade interaction is carried out to assess the effectiveness of vane sweep in reducing rotor-stator interaction noise. The results show that sweep is beneficial in reducing noise levels. Rotor wake twist or circumferential lean substantially influences the effectiveness of vane sweep. The orientation of vane sweep must be chosen to enhance the natural phase lag caused by wake lean, in which case rather small sweep angles substantially reduce the noise levels.

  18. Design and experimental results for a turbine with jet flap stator and jet flap

    NASA Technical Reports Server (NTRS)

    Bettner, J. L.; Blessing, J. O.

    1973-01-01

    The overall performance and detailed stator performance of a negative hub reaction turbine design featuring a moderately low solidity jet flap stator and a jet flap rotor were determined. Testing was conducted over a range of turbine expansion ratios at design speed. At each expansion ratio, the stator jet flow and rotor jet flow ranged up to about 7 and 8 percent, respectively, of the turbine inlet flow. The performance of the jet flap stator/jet flap rotor turbine was compared with that of a turbine which used the same jet flap rotor and a conventional, high solidity plan stator. The effect on performance of increased axial spacing between the jet stator and rotor was also investigated.

  19. Study of controlled diffusion stator blading. 1. Aerodynamic and mechanical design report

    NASA Technical Reports Server (NTRS)

    Canal, E.; Chisholm, B. C.; Lee, D.; Spear, D. A.

    1981-01-01

    Pratt & Whitney Aircraft is conducting a test program for NASA in order to demonstrate that a controlled-diffusion stator provides low losses at high loadings and Mach numbers. The technology has shown great promise in wind tunnel tests. Details of the design of the controlled diffusion stator vanes and the multiple-circular-arc rotor blades are presented. The stage, including stator and rotor, was designed to be suitable for the first-stage of an advanced multistage, high-pressure compressor.

  20. M-Phase N-Segment Flux-Reversal-Free Stator Switched Reluctance Machines

    Microsoft Academic Search

    N. S. Lobo; E. Swint; R. Krishnan

    2008-01-01

    This paper describes a class of switched reluctance machines (SRM) whose stators have no flux reversals. Previously published work describes a two-phase flux-reversal-free-stator SRM and this paper extends the concept to an SRM with any number of phases. For the first time in literature, SRMs with flux reversal free stators and flux reversal free rotor back irons are developed in

  1. Upstream-radiated rotor-stator interaction noise in mean swirling flow

    Microsoft Academic Search

    N. P EAKE

    2005-01-01

    A major component of the noise in modern aeroengines is rotor-stator interaction noise generated when the wake from the rotating fan impinges on a stator row downstream. An analytically based model for the prediction of upstream-radiated rotor-stator interaction noise is described, and includes the important effect of mean swirling flow on both the rotor wake evolution and the acoustic response.

  2. Bowed stators: An example of CFD applied to improve multistage compressor efficiency

    SciTech Connect

    Weingold, H.D.; Neubert, R.J.; Behlke, R.F.; Potter, G.E. [United Technologies Corp., East Hartford, CT (United States)

    1997-04-01

    Analysis of multistage compressor stator surface static pressure data reveals that the radial growth of suction surface corner separation prematurely separates core flow stator sections, limiting their pressure rise capability and generating endwall loss. Modeling of the stator flowfield, using a three-dimensional Euler analysis, has led to the development of bowed stator shapes, which generate radial forces that reduce diffusion rates in the suction surface corners, in order to delay the onset of corner separation. Experimental testing of the bowed stator concept in a three-stage research compressor has confirmed the elimination of suction surface corner separation, the resulting reduction of the endwall loss, and the increase in pressure rise capability of the stator core sections. This results in more robust pressure rise characteristics and substantially improved efficiency over the entire flow range of the compressor. The strong interaction effects of the bowed stator with the viscous endwall flowfield are shown to be predictable using a three-dimensional multistage Navier-Stokes analysis. This permits matching of the rotors to the altered stator exit profiles, in order to avoid potential stability limiting interactions. Application of bowed stators to a high bypass ratio engine eleven-stage high-pressure compressor has resulted in substantial improvement in efficiency, with no stability penalty.

  3. Analytic investigation of effect of end-wall contouring on stator performance

    NASA Technical Reports Server (NTRS)

    Boyle, R. J.; Rholik, H. E.; Goldman, L. J.

    1981-01-01

    Calculations show improved stator performance when the tip end wall was contoured so that the inlet area was greater than the exit area. Comparisons are made with previously published experimental data. The results of a parametric analysis of the effect contour geometry on the efficiency of a highly loaded axial stator are given. The maximum stator efficiency gain is about 0.8 percentage point, and this represents a 22 percent reduction in stator losses. The degree to which endwall contouring reduces the forces driving secondary flows was also examined. The driving forces for both cross channel and radial secondary flow were reduced.

  4. Luis Angel Salas Fonseca (1915-1999): maestro del diagnostico agricola

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The late Luis Angel Salas Fonseca, from the University of Costa Rica, was a world renowned researcher in agricultural entomology, plant-feeding nematodes, and plant-feeding mites. This paper provides a summary of his career and his important contributions to the study of pestiferous insects and mit...

  5. Bearing fault detection using wavelet packet transform of induction motor stator current

    Microsoft Academic Search

    Jafar Zarei; Javad Poshtan

    2007-01-01

    Induction motor vibrations, caused by bearing defects, result in the modulation of the stator current. In this research, bearing defect is detected using the stator current analysis via Meyer wavelet in the wavelet packet structure, with energy comparison as the fault index. The advantage of this method is in the detection of incipient faults. The presented method is evaluated using

  6. Models for Bearing Damage Detection in Induction Motors Using Stator Current Monitoring

    E-print Network

    Paris-Sud XI, Université de

    Models for Bearing Damage Detection in Induction Motors Using Stator Current Monitoring Martin Bl of rolling-element bearing faults on induction motor stator cur- rent. Bearing problems are one major cause for drive failures. Their detection is possible by vibration monitoring of charac- teristic bearing

  7. Control of Electromagnetic Forces on Stator Windings of Large Turbine-Generators

    Microsoft Academic Search

    C. A. Bucci; A. D. Coggeshall; K. F. Drexler; E. E. Gibbs

    1971-01-01

    In the past 20 years there has been a dramatic increase in kVA ratings of large turbine-generators, accompanied by a parallel increase in the electromagnetic forces acting on the stator windings. This has created an industry-wide problem of providing a stator winding support system which is capable of adequately restraining these forces to avoid impairment of machine reliability.

  8. Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow

    E-print Network

    Boyer, Edmond

    Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis

  9. Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow

    E-print Network

    Boyer, Edmond

    Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial with heat transfer along the stator, which corresponds to the experiment of Djaoui et al. [2]. Our results

  10. Transient analysis of cage induction machines under stator, rotor bar and end ring faults

    Microsoft Academic Search

    Hamid A. Toliyat; T.A. Lipo

    1995-01-01

    An analysis method is developed for modeling of multi phase cage induction motors with asymmetry in the stator, arising due to an interturn fault resulting in a disconnection of one or more coils making up a portion of a stator phase winding and any distribution and number of rotor bar and end-ring failures. The approach, based on the winding functions,

  11. A remote and sensorless stator winding thermal protection scheme for line-connected AC machines

    Microsoft Academic Search

    Sang Bin Lee; Thomas G. Habetler

    2002-01-01

    An advanced remote and sensorless thermal protection technique for line-connected AC machines is proposed in this paper. The proposed technique includes an algorithm for detecting abnormal cooling conditions due to reduced motor cooling ability in addition to a stator resistance (Rs)-based stator temperature (Ts) estimation scheme. The motor cooling ability monitoring algorithm can be implemented using the Rs estimates of

  12. State space model and simulation of long stator linear synchronous motor in maglev vehicle

    Microsoft Academic Search

    Fan cheng-zhi; Fang You-tong; Ye yun-yue; Li Zi-xing

    2003-01-01

    This paper presents a configuration of a long stator linear synchronous motor (LSLSM) for maglev vehicle systems; the foundational state-space model is developed for static and dynamic analysis. The relative effects between propel and the levitation force within the stator and the mover are discussed. The simulation results of the propelling force and the levitating force are also presented.

  13. Analytical and Experimental Study of Gearbox Mechanical Effect on the Induction Machine Stator Current Signature

    Microsoft Academic Search

    Shahin Hedayati Kia; Humberto Henao; GÉrard-AndrÉ Capolino

    2009-01-01

    The aim of this paper is the analytical and experimental study of a gearbox by using the stator current signature analysis in the driving induction machines. The mechanical study using the vibration signal analysis has been well studied before. Recently, some works have been performed to observe the vibration components of the mechanical part in the stator current spectrum for

  14. The magneto motive force of a novel dual stator-winding induction generator

    Microsoft Academic Search

    Wenxin Huang; Yuwen Hu; Feifei Bu; Kai Shi

    2010-01-01

    The magneto motive force (MMF) of a novel dual stator-winding induction generator (DWIG) for wind power application is analyzed in this paper. There are two sets of windings embedded in the stator slots. One is 3-phase control winding, and the other is 6-phase power winding. A static excitation converter (SEC) is connected to the control winding to provide the variable

  15. Application of partial discharge testing to motor and generator stator winding maintenance

    Microsoft Academic Search

    Greg C. Stone; Howard G. Sedding; Michael J. Costello

    1996-01-01

    Deterioration of stator winding insulation continues to be one of the predominant causes of large motor and generator failures. Over the past several years, practical methods have been developed for measuring the partial discharge activity in the high voltage insulation of stator windings, since partial discharges are a symptom of most of the insulation failure mechanisms in motors and generators

  16. A Review of Results From Thermal Cycling Tests of Hydrogenerator Stator Windings

    Microsoft Academic Search

    Maren Istad; Magne Runde; Arne Nysveen

    2011-01-01

    Thermal cycling of generators, occurring during in- termittent operation of power stations, increases the thermome- chanical stress on the stator groundwall insulation and can, there- fore, contribute to failure of the generator. Thermal cycling stresses can, to some extent, be replicated and accelerated in laboratory tests. Such tests are performed to ascertain whether a new stator winding insulation system can

  17. Noise produced by the interaction of a rotor wake with a swept stator blade

    Microsoft Academic Search

    E. Envia; E. J. Kerschen

    1984-01-01

    An analysis is developed for the noise generated by the interaction of rotor viscous wakes and a single swept stator vane. The stator vane spans a channel with infinite parallel walls which contains a uniform subsonic mean flow. High frequency wakes, for which the noise generation is concentrated at the vane leading edge, are considered. The general wake pattern is

  18. Tuning the stator resistance of induction motors using artificial neural network

    SciTech Connect

    Cabrera, L.A.; Elbuluk, M.E.; Husain, I. [Univ. of Akron, OH (United States). Dept. of Electrical Engineering] [Univ. of Akron, OH (United States). Dept. of Electrical Engineering

    1997-09-01

    Tuning the stator resistance of induction motors is very important, especially when it is used to implement direct torque control (DTC) in which the stator resistance is a main parameter. In this paper, an artificial network (ANN) is used to accomplish tuning of the stator resistance of an induction motor. The parallel recursive prediction error and backpropagation training algorithms were used in training the neural network for the simulation and experimental results, respectively. The neural network used to tune the stator resistance was trained on-line, making the DTC strategy more robust and accurate. Simulation results are presented for three different neural-network configurations showing the efficiency of the tuning process. Experimental results were obtained for the one of the three neural-network configuration. Both simulation and experimental results showed that the ANN have tuned the stator resistance in the controller to track actual resistance of the machine.

  19. Noise produced by the interaction of a rotor wake with a swept stator blade

    NASA Astrophysics Data System (ADS)

    Envia, E.; Kerschen, E. J.

    1984-10-01

    An analysis is developed for the noise generated by the interaction of rotor viscous wakes and a single swept stator vane. The stator vane spans a channel with infinite parallel walls which contains a uniform subsonic mean flow. High frequency wakes, for which the noise generation is concentrated at the vane leading edge, are considered. The general wake pattern is expanded in spanwise modes and solutions for each mode are derived using the Wiener-Hopf technique applied to the equations in the nonorthogonal coordinates. Closed form expressions for the acoustic farfield are obtained. The results of the analysis are used in parametric calculations of rotor viscous wake-stator vane interactions in order to study the effectiveness of sweep as a noise reduction mechanism. For the cases studied, moderate stator sweep angles produce sizeable reductions in the level of the farfield noise. The presence of rotor wake circumferential lean actually increases the noise reduction produced by moderate stator sweep angles.

  20. Effect of upstream rotor vortical disturbances on the time-averaged performance of axial compressor stators. Part 1: Framework of technical approach and wake-stator blade interactions

    SciTech Connect

    Valkov, T.V. [Shell International Gas Ltd., London (United Kingdom); Tan, C.S. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Gas Turbine Lab.

    1999-07-01

    In a two-part paper, key computed results from a set of first-of-a-kind numerical simulations on the unsteady interaction of axial compressor stators with upstream rotor wakes and tip leakage vortices are employed to elucidate their impact on the time-averaged performance of the stator. Detailed interrogation of the computed flowfield showed that for both wakes and tip leakage vortices, the impact of these mechanisms can be described on the same physical basis. Specifically, there are two generic mechanisms with significant influence on performance: reversible recovery of the energy in the wakes/tip vortices (beneficial) and the associated nontransitional boundary layer response (detrimental). In the presence of flow unsteadiness associated with rotor wakes and tip vortices, the efficiency of the stator under consideration is higher than that obtained using a mixed-out steady flow approximation. The effects of tip vortices and wakes are of comparable importance. The impact of stator interaction with upstream wakes and vortices depends on the following parameters: axial spacing, loading, and the frequency of wake fluctuations in the rotor frame. At reduced spacing, this impact becomes significant. The most important aspect of the tip vortex is the relative velocity defect and the associated relative total pressure defect, which is perceived by the stator in the same manner as a wake. In Part 1, the focus will be on the framework of technical approach, and the interaction of stator with the moving upstream rotor wakes.

  1. Effect of upstream rotor vortical disturbances on the time-averaged performance of axial compressor stators. Part 2: Rotor tip vortex/streamwise vortex-stator blade interactions

    SciTech Connect

    Valkov, T.V. [Shell International Gas Ltd., London (United Kingdom); Tan, C.S. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Gas Turbine Lab.

    1999-07-01

    In a two-part paper, key computed results from a set of first-of-a-kind numerical simulations on the unsteady interaction of axial compressor stator with upstream rotor wakes and tip leakage vortices are employed to elucidate their impact on the time-averaged performance of the stator. Detailed interrogation of the computed flowfield showed that for both wakes and tip leakage vortices, the impact of these mechanisms can be described on the same physical basis. Specifically, there are two generic mechanisms with significant influence on performance: reversible recovery of the energy in the wakes/tip vortices (beneficial) and the associated nontransitional boundary layer response (detrimental). In the presence of flow unsteadiness associated with rotor wakes and tip vortices, the efficiency of the stator under consideration is higher than that obtained using a mixed-out steady flow approximation. The effects of tip vortices and wakes are of comparable importance. The impact of stator interaction with upstream wakes and vortices depends on the following parameters: axial spacing, loading, and the frequency of wake fluctuations in the rotor frame. At reduced spacing, this impact becomes significant. The most important aspect of the tip vortex is the relative velocity defect and the associated relative total pressure defect, which is perceived by the stator in the same manner as a wake. In Part 2, the focus will be on the interaction of stator with the moving upstream rotor tip and streamwise vortices, the controlling parametric trends, and implications on design.

  2. Interactions of a propeller with a stator-induced circumferentially varying flow

    NASA Astrophysics Data System (ADS)

    Farnsworth, John; Amitay, Michael; Beal, David; Huyer, Stephen A.

    2012-02-01

    The interactions of a circumferentially varying stator cascade and a downstream fixed pitch propeller were investigated experimentally. The global performance of the components and the coupled system were systematically investigated through force and moment measurements on the propulsor model in a water tunnel. In addition, the wake of the cyclic stator cascade with and without the propeller was investigated downstream from a propulsor model using the Stereoscopic PIV technique. A cyclic distribution of the stators' deflections resulted in non-axisymmetric distributions of the flow field downstream of the stator array. The stator distribution alone produced a significant side force that increased linearly with stator pitch amplitude. When a propeller was incorporated downstream from the cyclic cascade, the side force from the stator cascade was reduced, but a small normal force and pitching moment were created. The generation of these secondary forces and moments can be related to the redistribution of the tangential flow from the cyclic cascade into the axial direction by the retreating and advancing blade states of the fixed pitch propeller.

  3. Acoustic Benefits of Stator Sweep and Lean for a High Tip Speed Fan

    NASA Technical Reports Server (NTRS)

    Woodward, Richard P.; Gazzaniga, John A.; Bartos, Linda J.; Hughes, Christopher E.

    2002-01-01

    A model high-speed fan stage was acoustically tested in the NASA Glenn 9- by 15-Foot Low Speed Wind Tunnel at takeoff/approach flight conditions. The fan was designed for a corrected rotor tip speed of 442 m/s (1450 ft/s), and had a powered core, or booster stage, giving the model a nominal bypass ratio of 5. The model also had a simulated engine pylon and nozzle bifurcation contained within the bypass duct. The fan was tested with three stator sets to evaluate acoustic benefits associated with a swept and leaned stator and with a swept integral vane/frame stator which incorporated some of the swept and leaned features as well as eliminated some of the downstream support structure. The baseline fan with the wide chord rotor and baseline stator approximated a current GEAE CF6 engine. A flyover effective perceived noise level (EPNL) code was used to generate relative EPNL values for the various configurations. Flyover effective perceived noise levels (EPNL) were computed from the model data to help project noise benefits. A tone removal study was also performed. The swept and leaned stator showed a 3 EPNdB reduction at lower fan speeds relative to the baseline stator; while the swept integral vane/frame stator showed lowest noise levels at intermediate fan speeds. Removal of the bypass blade passage frequency rotor tone (BPF) showed a 4 EPNdB reduction for the baseline and swept and leaned stators, and a 6 EPNdB reduction for the swept integral vane/ frame stator. Therefore, selective tone removal techniques such as active noise control and/or tuned liner could be particularly effective in reducing noise levels for certain fan speeds.

  4. Single stage evaluation of highly loaded high Mach number compressor stages. 6: Data and performance of cantilevered stator

    NASA Technical Reports Server (NTRS)

    Merrow, A. S.

    1972-01-01

    A compressor stage with a rotor tip speed of 1600 ft/sec was tested to evaluate its performance with a cantilevered stator and a rotating inner shroud beneath the stator. Both the rotor blades and the stator vanes were composed of multiple circular arc airfoil sections. Comparison of data taken during this test of the cantilevered stator and previous tests with the same compressor and airfoil geometry in a shroud stator configuration showed only slight differences in stage performance with no significant effect on overall efficiency. However, the severity of the stator wake near the rotating hub was decreased at all flows including the near surge condition. Stall and wise open discharge corrected weight flows were the same as for the shrouded stator configuration.

  5. Non-linear dynamic of rotor-stator system with non-linear bearing clearance

    E-print Network

    Jean-Jacques Sinou; Fabrice Thouverez

    2008-01-19

    The study deals with a rotor-stator contact inducing vibration in rotating machinery. A numerical rotor-stator system, including a non-linear bearing with Hertz contact and clearance is considered. To determine the non-linear responses of this system, non-linear dynamic equations can be integrated numerically. However, this procedure is both time consuming and costly to perform. The aim of this Note is to apply the Alternate Frequency/Time Method and the 'path following continuation' in order to obtain the non-linear responses to this problem. Then the orbits of rotor and stator responses at various speeds are investigated.

  6. Computational analysis of rotor-stator interaction in turbomachinery using zonal techniques

    NASA Technical Reports Server (NTRS)

    Madavan, Nateri K.; Rai, Man Mohan

    1990-01-01

    The development of CFD zonal techniques which allow more intensive computational treatment in some regions than in others, in conjunction with robust, high-accuracy algorithms for the numerical solution of the Navier-Stokes equations, is presently shown to have facilitated the investigation of rotor-stator interactions in turbomachinery. Attention is given to integration schemes with two and three spatial dimensions, the conservative 'patched' and the nonconservative zonal boundary schemes, and such natural boundary conditions as those of the endwall, the stator inlet, the airfoil surface, and the rotor exit. Illustrative three-dimensional rotor-stator interaction calculations are presented.

  7. Field weakening for a doubly salient motor with stator permanent magnets

    SciTech Connect

    Lipo, T.A.; Liao, Y.; Liang, F.

    1995-10-03

    A device for field weakening in a doubly-salient variable reluctance motor having permanent magnets in the stator. The field weakening increases the constant power range of the motor and is accomplished by controlled movement of steel insets toward and away from the sides of the stator proximate the permanent magnets to provide a controllable by-pass flux path thereabout. Alternatively, the field weakening may be accomplished by a flux by-pass collar which may be angularly positioned around the stator to bridge the permanent magnets of the motor with discrete magnetic sections, thereby providing an alternate by-pass flux path around the permanent magnets in addition to the main air gap flux path. A third alternative means for maintaining a constant power range is accomplished by controlled axial sliding of the permanent magnets themselves into and out from the stator. 5 figs.

  8. Investigation about Rotor-stator Interaction with an Adjustable Leaned Vane Blade

    NASA Astrophysics Data System (ADS)

    Wu, Yadong; Tian, Jie; Ouyang, Hua; Du, Zhaohui; Liu, Haijian

    2014-12-01

    This paper focuses on the noise reduction benefits of stator lean effect for rotor-stator interaction. The compressor with 3 blade lean angle of downstream stator was investigated by experimental and numerical study. The noise spectra of the acoustic measurement were obtained by the outside noise test. And the tone noise was extracted from the total noise sound pressure level (SPL). The unsteady loading of the stators' blade surface were also obtained. The pressure fluctuation amplitude was extracted from the numerical study, and the phase distribution of the wake presented the detail distribution of the wake phase. The numerical study shows that lean positive has less unsteady loading than negative, and lean positive case has the maximum phase lag.

  9. Preliminary Analysis of Axial-Flow Compressors Having Supersonic Velocity at the Entrance of the Stator

    NASA Technical Reports Server (NTRS)

    Ferri, Antonio

    1949-01-01

    A supersonic compressor design having supersonic velocity at the entrance of the stator is analyzed on the assumption of two-dimensional flow. The rotor and stator losses assumed in the analysis are based on the results of preliminary supersonic cascade tests. The results of the analysis show that compression ratios per stage of 6 to 10 can be obtained with adiabatic efficiency between 70 and 80 percent. Consideration is also given in the analysis to the starting, stability, and range of efficient performance of this type of compressor. The desirability of employing variable-geometry stators and adjustable inlet guide vanes is indicated. Although either supersonic or subsonic axial component of velocity at the stator entrance can be used, the cascade test results suggest that higher pressure recovery can be obtained if the axial component is supersonic.

  10. The detection of inter-turn short circuits in the stator windings of operating motors

    Microsoft Academic Search

    Gojko M. Joksimovic; Jim Penman

    2000-01-01

    This paper develops a winding-function-based method for modeling polyphase cage induction motors with inter-turn short circuits in the machine stator winding. Analytical consideration which sheds light on some components of the stator current spectra of both healthy and faulty machines is developed. It is shown that, as a result of the nature of the cage rotor, no new frequency components

  11. Hall effect sensors embedded within two-pole toothless stator assembly

    NASA Technical Reports Server (NTRS)

    Denk, Joseph (Inventor); Grant, Richard J. (Inventor)

    1994-01-01

    A two-pole toothless PM machine employs Hall effect sensors to indicate the position of the machine's rotor relative to power windings in the machine's stator. The Hall effect sensors are located in the main magnetic air gap underneath the power windings. The main magnetic air gap is defined by an outer magnetic surface of the rotor and an inner surface of the stator's flux collector ring.

  12. Analysis of multi-phase permanent magnet motors with concentrated non-overlapping stator windings

    Microsoft Academic Search

    Youlong Wang; Wen Xuhui

    2010-01-01

    This paper describes a method to analyze and design PM motors with non-overlapping windings and any number of phases. A unified two poles model of multi-phase PM motors with non-overlapping stator windings is discussed. Based on this model the analytical harmonic expressions of stator MMF are derived. The harmonic interaction between inductance components is analyzed. The influences of key design

  13. An implicit Navier-Stokes analysis of turbine rotor-stator interaction

    NASA Technical Reports Server (NTRS)

    Gibeling, Howard J.; Buggeln, Richard C.; Chen, Shyi-Yaung; Mcconnaughey, Helen V.

    1988-01-01

    An implicit Navier-Stokes analysis using a single deforming mesh has been developed for the unsteady rotor-stator interaction problem. The technique has been used to simulate the flow through a turbine stator-rotor stage. Periodic two-dimensional solutions have been obtained using 1000 time steps per cycle without iteration at each time step. Computed surface pressure distributions compare favorably with experimental data available for this configuration.

  14. A single-phase reluctance generator with permanent magnets between stator teeth

    Microsoft Academic Search

    K. Kurihara; T. Kubota; T. Kosaka; T. Nakamura

    2010-01-01

    This paper presents a novel single-phase reluctance generator with low-cost ferrite magnets between adjacent stator teeth. The stator has both 4-pole field and 8-pole armature windings. The armature windings are connected to the input terminals of a single-phase full-bridge rectifier circuit as AC power source. The DC output terminals are connected to the field windings to increase the excited flux.

  15. An Adaptive Sliding Stator Flux Observer for a Direct-Torque-Controlled IPM Synchronous Motor Drive

    Microsoft Academic Search

    Zhuang Xu; M. F. Rahman

    2007-01-01

    This paper focuses on performance improvements of the stator flux estimation for a direct-torque-controlled interior permanent magnet synchronous motor drive. In this paper, an adaptive sliding observer is presented to estimate the stator flux linkage based on the motor current model. The experimental results show that the proposed observer has been able to deliver more accurate estimation than an open-loop

  16. SSME seal test program: Test results for smooth, hole-pattern and helically-grooved stators

    NASA Technical Reports Server (NTRS)

    Childs, Dara W.

    1987-01-01

    All of the listed seals were tested in a liquid Halon test facility at high Reynolds numbers. In addition, a helically-grooved-stator seal was tested in an air seal facility. An analysis of the test results with comparisons to theoretical predictions supports the following conclusions: (1) For small seals, the Hirs' friction-factor model is more restricted than had been thought; (2) For smooth seals, predictions of stiffness and damping improve markedly as the radical clearance is reduced; (3) Friction-factor data for hole-pattern-seal stators frequently deviates from the Hirs model; (4) Predictions of stiffness and damping coefficients for hole-pattern-stator seals is generally reasonable; (5) Tests for the hole-pattern stators at reduced clearances show no clear optimum for hole-pattern seals with respect to either hole-area ratio or hole depth to minimum clearance ratios; (6) Tests of these hole-pattern stators show no significant advantage in net damping over smooth seals; (7) Tests of helically-grooved seal stators in Halon show reasonable agreement between theory and prediction for leakage and direct stiffness but poor agreement for the net damping coefficient.

  17. Design Selection and Analysis of a Swept and Leaned Stator Concept

    NASA Technical Reports Server (NTRS)

    Envia, Edmane; Nallasamy, M.

    1998-01-01

    This report describes a theoretical design and analysis study of the benefits of vane sweep and lean for reducing rotor- stator interaction tone noise. It is shown that the kinematic relationship between the rotor wakes and stator vanes is the principal factor in determining the achievable noise reductions. Vane sweep and lean control rotor wake skewing as seen by the stator vanes and hence influence the number of wake intersections per vane. An increase in the number of intersections reduces noise levels. Hence, to reduce rotor-stator noise, van sweep and lean must be chosen in such a way as to increase wake intersections per vane. A simple design rule is thus proposed which requires a sweep configuration that puts the vane tip downstream of its root and a vane lean that is in the direction of the rotor rotation. A detailed comparison of the predicted and measured noise reductions for a swept and leaned stator is then carried out. Overall, these comparisons show that the predicted benefits of a swept and leaned stator are in good agreement, qualitative as well as quantitative, with the measured reductions for the fan speeds relevant to noise certification procedure. Furthermore, the results also demonstrate the validity of design criterion and the theoretical tools used in this study.

  18. Quantification of flagellar motor stator dynamics through in vivo proton-motive force control.

    PubMed

    Tipping, Murray J; Steel, Bradley C; Delalez, Nicolas J; Berry, Richard M; Armitage, Judith P

    2013-01-01

    The bacterial flagellar motor, one of the few rotary motors in nature, produces torque to drive the flagellar filament by ion translocation through membrane-bound stator complexes. We used the light-driven proton pump proteorhodopsin (pR) to control the proton-motive force (PMF) in vivo by illumination. pR excitation was shown to be sufficient to replace native PMF generation, and when excited in cells with intact native PMF generation systems increased motor speed beyond the physiological norm. We characterized the effects of rapid in vivo PMF changes on the flagellar motor. Transient PMF disruption events from loss of illumination caused motors to stop, with rapid recovery of their previous rotation rate after return of illumination. However, extended periods of PMF loss led to stepwise increases in rotation rate upon PMF return as stators returned to the motor. The rate constant for stator binding to a putative single binding site on the motor was calculated to be 0.06 s(-1). Using GFP-tagged MotB stator proteins, we found that transient PMF disruption leads to reversible stator diffusion away from the flagellar motor, showing that PMF presence is necessary for continued motor integrity, and calculated a stator dissociation rate of 0.038 s(-1). PMID:23216828

  19. A comparison of experimental and theoretical results for labyrinth gas seals with honeycomb stators. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Hawkins, Lawrence Allen

    1988-01-01

    Experimental results for the rotordynamic stiffness and damping coefficients of a labyrinth -rotor honeycomb-stator seal are presented. The coefficients are compared to the coefficients of a labyrinth-rotor smooth-stator seal having the same geometry. The coefficients are compared to analytical results from a two-control-volume compressible flow model. The experimental results show that the honeycomb stator configuration is more stable than the smooth stator configuration at low rotor speeds. At high rotor speeds and low clearance, the smooth stator seal is more stable. The theoretical model predicts the cross-coupled stiffness of the honeycomb stator seal correctly within 25 percent of measured values. The model provides accurate predictions of direct damping for large clearance seals. Overall, the model does not perform as well for low clearance seals as for high clearance seals.

  20. A stator for a self-running, ultrasonically-levitated sliding stage.

    PubMed

    Koyama, Daisuke; Nakamura, Kentaro; Ueha, Sadayuki

    2007-11-01

    Here we propose a self-running, ultrasonically-levitated sliding stage and investigate the levitation and propulsion characteristics of its stator. The stator consists of two aluminum beams and four PZT plates, which have two-paired bimorph configurations. A flexural standing wave was generated along the beam by applying an input voltage to the PZTs, and the stator could be levitated from a flat substrate by the acoustic radiation force generated by its own vibrating beam. The size of the stator was optimized using finite-element analysis (FEA) to maximize the vibration displacement amplitude of the beam. The flexural vibration modes at 24.3 and 102 kHz were the most prominent vibration modes having large displacement amplitudes. The stator was levitated at 23.2 and 96.1 kHz, which are close to the frequencies predicted by the FEA results. A standing wave was observed along the beam. The experimental and the simulated results showed good agreement. The levitation distance h was measured by varying the vibration displacement amplitude of the beam u, and was found to be proportional to u. When a traveling wave was excited along the beam by controlling the temporal phase difference of the two transducers, the stator could be made to hover and to move in the opposite direction to the traveling wave. The stator moved in the positive direction when the phase difference was in the ranges 0 degrees to 200 degrees and 310 degrees to 360 degrees, and in the negative direction when the phase difference was between 220 degrees and 260 degrees. PMID:18051168

  1. Effect of endwall cooling on secondary flows in turbine stator vanes

    NASA Technical Reports Server (NTRS)

    Goldman, L. J.; Mclallin, K. L.

    1977-01-01

    The effect of endwall cooling on the secondary flow behavior and the aerodynamic performance of a core turbine stator vane was determined. The investigation was conducted in a cold-air, full-annular cascade, where three-dimensional effects were obtained. Two endwall cooling configurations were tested. In the first configuration, the cooling holes were oriented so that the coolant was injected in line with the inviscid streamline direction. In the second configuration, the coolant was injected at an angle of 15 deg to the inviscid streamline direction and oriented towards the vane pressure stator. In both cases the stator vanes were solid and uncooled so that the effect of endwall cooling was obtained directly. Total-pressure surveys were taken downstream of the stator vanes over a range of cooling flows at the design, mean-radius, critical velocity ratio of 0.778. Changes in the total-pressure contours downstream of the vanes were used to obtain the effect of endwall cooling on the secondary flows in the stator.

  2. Extension of Useful Operating Range of Axial-Flow Compressors by Use of Adjustable Stator Blades

    NASA Technical Reports Server (NTRS)

    Sinnette, John T; Voss, William J

    1948-01-01

    A theory has been developed for resetting the blade angles of an axial-flow compressor in order to improve the performance at speeds and flows other than the design and thus extend the useful operating range of the compressor. The theory is readily applicable to the resetting of both rotor and stator blades or to the resetting of only the stator blades and is based on adjustment of the blade angles to obtain lift coefficients at which the blades will operate efficiently. Calculations were made for resetting the stator blades of the NACA eight-stage axial-flow compressor for 75 percent of design speed and a series of load coefficients ranging from 0.28 to 0.70 with rotor blades left at the design setting. The NACA compressor was investigated with three different blade settings: (1) the design blade setting, (2) the stator blades reset for 75 percent of design speed and a load coefficient of 0.48, and (3) the stator blades reset for 75 percent of design speed and a load coefficient of 0.65.

  3. Component Performance Investigation of J71 Experimental Turbine VIII : Effect of First-stator Adjustment; Internal Flow Conditions of J71-97 Turbine with 70-percent-design Stator Area

    NASA Technical Reports Server (NTRS)

    Petrash, Donald A; Schum, Harold J; Davison, Elmer H

    1956-01-01

    Results of a survey investigation of the J71-97 experimental three-stage turbine equipped with a first-stator area 70 percent pf design are presented and compared with the turbine with a first-stator area 97 percent of design.

  4. Stator optimization and evaluation method in a surface acoustic wave motor

    NASA Astrophysics Data System (ADS)

    Kong, Deqing; Kuribayashi Kurosawa, Minoru

    2015-07-01

    The interdigital transducer (IDT) of a surface acoustic wave (SAW) motor comprises two unidirectional IDTs (U-IDTs), including a driving IDT (D-IDT) and a reflector IDT (R-IDT). In order to improve the conductance of the U-IDT, the distance between the D-IDT and the R-IDT will be adjusted. The novel U-IDT will be investigated by simulation and some measurements. The novel stator will be fabricated by the basic semiconductor planar process. On the other hand, a stator evaluation method for the SAW motor will be reported. Lastly, through the calculation of the wave power, the measured vibration amplitude and stator recycle efficiency will be unified.

  5. Stator-flux-based vector control of induction machines in magnetic saturation

    SciTech Connect

    Hofmann, H.; Sanders, S.R.; Sullivan, C. [Univ. of California, Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Sciences

    1995-12-31

    In many variable-torque applications of induction machines it is desirable to operate the machine in magnetic saturation, thus allowing the machine to produce higher torques. Stator-flux-based control schemes have been developed as a possible alternative method of control of induction machines. Stator-flux-based control schemes need not depend on the magnetic characteristics of the machine, and hence are potentially more robust and easier to implement in magnetic saturation than rotor-flux-based control. The authors analyze the induction machine in saturation using a nonlinear {pi}-model of the machine`s magnetics, and develop a control scheme in the stator flux reference frame that is independent of magnetics. Experiments carried out on a 3 hp, 1,800 rpm wound rotor induction machine show smooth operation of the control scheme at torque levels up to at least 4 times rated torque.

  6. Predicting broadband noise from a stator vane of a gas turbine engine

    NASA Technical Reports Server (NTRS)

    Hanson, Donald B. (Inventor)

    2002-01-01

    A computer-implemented model of fan section of a gas turbine engine accounts for the turbulence in the gas flow emanating from the rotor assembly and impinging upon an inlet to the stator vane cascade. The model allows for user-input variations in the sweep and/or lean angles for the stator vanes. The model determines the resulting acoustic response of the fan section as a function of the turbulence and the lean and/or sweep angles of the vanes. The model may be embodied in software that is rapidly executed in a computer. This way, an optimum arrangement in terms of fan noise reduction is quickly determined for the stator vane lean and sweep physical positioning in the fan section of a gas turbine engine.

  7. Synthesis and evaluation of molecular rotors with large and bulky tert-butyldiphenylsilyloxy-substituted trityl stators.

    PubMed

    Arcos-Ramos, Rafael; Rodríguez-Molina, Braulio; Romero, Margarita; Méndez-Stivalet, J Manuel; Ochoa, María Eugenia; Ramírez-Montes, Pedro I; Santillan, Rosa; Garcia-Garibay, Miguel A; Farfán, Norberto

    2012-08-17

    The search for voluminous stators that may accommodate large rotator units and speed rotational dynamics in the solid state led us to investigate a simple and efficient method for the synthesis of molecular rotors with tert-butyldiphenylsilyl-protected (TBDPS) triphenylmethyl stators. Additionally, solid state characterization of these systems with two-, four-, and six-TBDPS groups provided us with a description of their crystallinity and thermal stability. Among them, molecular rotor 7c with the largest and most symmetric stator resulting from six peripheral silyl groups showed the best tendency to crystallize, and the study of its isotopologue 7c-d(4) by solid state (2)H NMR revealed a 2-fold motion of the 1,4-diethynylphenylene-d(4) rotator in the kHz regime. PMID:22812677

  8. Detection of stator short circuit faults in three-phase induction motors using motor current zero crossing instants

    Microsoft Academic Search

    Abhisek Ukil; Shuo Chen; Andrea Andenna

    2011-01-01

    Stator faults typically have a significant share amongst the common type of faults in industrial three-phase induction (asynchronous) motors. This paper presents a motor current signature analysis (MCSA)-based diagnostics of the stator winding short circuit fault. This type of fault happens due to the destruction of the turn insulation, and can be very detrimental causing motor shutdown. Instead of traditional

  9. Analysis of currents and an electromagnetic torque in steady states of induction squirrel-cage motors with asymmetric stator windings

    Microsoft Academic Search

    T. J. Sobczyk; K. Weinreb

    1988-01-01

    Contents The paper presents a mathematical model of an asynchronous squirrel-cage motor with arbitrarily asymmetrical stator windings. The structure of the mathematical model equations is analysed in detail using the assumption about the symmetry of the rotor cage. A particular arrangement of the mutual inductance matrix of stator windings and rotor cage meshes is shown. As a result of applying

  10. A Reconfigurable Motor for Experimental Emulation of Stator Winding Interturn and Broken Bar Faults in Polyphase Induction Machines

    Microsoft Academic Search

    Chia-Chou Yeh; Gennadi Y. Sizov; Ahmed Sayed-Ahmed; Nabeel A. O. Demerdash; Richard J. Povinelli; Edwin E. Yaz; Dan M. Ionel

    2008-01-01

    The benefits and drawbacks of a 5-hp reconfigurable induction motor, which was designed for experimental emulation of stator winding interturn and broken rotor bar faults, are presented in this paper. It was perceived that this motor had the potential of quick and easy reconfiguration to produce the desired stator and rotor faults in a variety of different fault combinations. Hence,

  11. A Reconfigurable Motor for Experimental Emulation of Stator Winding InterTurn and Broken Bar Faults in Polyphase Induction Machines

    Microsoft Academic Search

    Chia-Chou Yehl; G. Y. Sizov; A. Sayed-Ahmed; N. A. O. Demerdash; R. J. Povinelli; E. E. Yaz; D. M. Ionel

    2007-01-01

    The advantages and demerits of a 5-hp reconfigurable induction motor, which was designed for experimental emulation of stator winding inter-turn and broken rotor bar faults, are presented in this paper. It was perceived that this motor has the potential of quick and easy reconfiguration to produce the desired stator and rotor faults in a variety of different fault combinations. Accordingly,

  12. A bio-inspired piezoelectric motor with simple structured asymmetric stator

    NASA Astrophysics Data System (ADS)

    Zhou, Maoying; Ruan, Yuan; Liu, Weiting; Huang, Shuo; Fu, Xin

    2014-04-01

    A new type of micro rotary motor with a single piezoelectric stack actuator has been proposed, developed and tested. The conventional principle of elliptical motion is realized by a proposed mechanism which utilizes a Y-shaped stator and a ring rotor, and the biomimetic gait of an inchworm is achieved by integrating one piezoelectric stack actuator into the stator. The performance of the motor is predicted on the basis of computational simulation. An experimental setup was built to validate the working principles and evaluate the performance. Preliminary results have verified the working principle. Differences between the measured and predicted performances of the motor are analyzed.

  13. Damages of windings of a three-phase slip-ring induction machine having parallel paths in the stator or in the rotor

    Microsoft Academic Search

    S. Rawicki

    1988-01-01

    Contents The following damages of a three-phase slip-ring induction machine having parallel paths in the stator or in the rotor are analysed in the paper: break in a parallel path of the stator or the rotor winding, internal short-circuit in the stator winding, earth fault of the stator winding. The mathematical model of asymmetrical states is presented. For the case

  14. Digital signal processing control of induction machine`s torque and stator flux utilizing the direct stator flux field orientation method

    SciTech Connect

    Seiz, J.B.

    1997-04-01

    This paper presents a review of the Direct Stator Flux Field Orientation control method. This method can be used to control an induction motor`s torque and flux directly and is the application of interest for this thesis. This control method is implemented without the traditional feedback loops and associated hardware. Predictions are made, by mathematical calculations, of the stator voltage vector. The voltage vector is determined twice a switching period. The switching period is fixed throughout the analysis. The three phase inverter duty cycle necessary to control the torque and flux of the induction machine is determined by the voltage space vector Pulse Width Modulation (PWM) technique. Transient performance of either the flux or torque requires an alternate modulation scheme which is also addressed in this thesis. A block diagram of this closed loop system is provided. 22 figs., 7 tabs.

  15. Effects of long-chord acoustically treated stator vanes on fan noise. 2: Effect of acoustical treatment

    NASA Technical Reports Server (NTRS)

    Dittmar, J. H.; Scott, J. N.; Leonard, B. R.; Stakolich, E. G.

    1976-01-01

    A set of long chord stator vanes was designed to replace the vanes in an existing fan stage. The long chord stator vanes consisted of a turning section and axial extension pieces, all of which incorporated acoustic damping material. The long chord stator vanes were tested in two lengths, with the long version giving more noise reduction than the short, primarily because of the additional lining material. The noise reduction achieved with the acoustically treated long chord stator vanes was compared with the reduction achieved by an acoustically treated exhaust splitter. The long chord stator was at least as good as the splitter as a method for incorporating acoustic lining material. In addition, comparing an acoustic three ring inlet and an acoustic wall-only inlet discloses that the wall-only inlet could be used in an engine where the noise reduction requirements are not too stringent.

  16. The effects of turbulence and stator/rotor interactions on turbine heat transfer. I - Design operating conditions

    NASA Technical Reports Server (NTRS)

    Blair, M. F.; Dring, R. P.; Joslyn, H. D.

    1988-01-01

    A combined experimental and analytical program was conducted to examine the effects of inlet turbulence, stator-rotor axial spacing, and relative circumferential spacing of first and second stators on turbine airfoil heat transfer. The experimental portion of the study was conducted in a large-scale (approximately 5X engine), ambient temperature, stage-and-a-half rotating turbine model. The data indicate that while turbine inlet turbulence can have a very strong impact on the first stator heat transfer, its impact in downstream rows is minimal. The effects on heat transfer produced by relatively large changes in stator/rotor spacing or by changing the relative row-to-row circumferential positions of stators were very small. Analytical results consist of airfoil heat transfer distributions computed with a finite-difference boundary layer code.

  17. Fourier and wavelet transformations for the fault detection of induction motor with stator current

    Microsoft Academic Search

    Sang-Hyuk Lee; Sungshin Kim; Jang Mok Kim; Man Hyung Lee

    2004-01-01

    In this literature, fault detection of an induction motor is carried out using the information of stator current. After preprocessing actual data, Fourier and wavelet transforms are applied to detect characteristics under the healthy and various faulted conditions. The most reliable phase current among 3-phase currents is selected by the fuzzy entropy. Data are trained with a neural network system,

  18. Stator current harmonics and their causal vibrations: a preliminary investigation of sensorless vibration monitoring applications

    Microsoft Academic Search

    Caryn M. Riley; Brian K. Lin; Thomas G. Habetler; Gerald B. Kliman

    1999-01-01

    This paper presents an initial study into the relationship between vibration and current harmonics of electric motors, including the effect of externally induced vibrations. This relationship was investigated experimentally on both new motors, on a vibration stand, and a motor with bearing wear. Both theory and experimental results show that a change in the RMS value of the stator current

  19. Wind Turbine Bearing Failure Detection Using Generator Stator Current Homopolar Component

    E-print Network

    Paris-Sud XI, Université de

    Wind Turbine Bearing Failure Detection Using Generator Stator Current Homopolar Component Ensemble for stationary and non stationary cases. Index Terms-Wind turbine, induction generator, bearing failure, ensemble developed for wind turbine electric generator condition monitoring in order to prolong their life span

  20. Sexual selection and the fitness consequences of male body size in the seed beetle Stator limbatus

    Microsoft Academic Search

    UDO M. SAVALLI; CHARLES W. FOX

    1998-01-01

    We examined sexual selection on male body size in a laboratory population of the seed beetle,Stator limbatus, and the fitness consequences to females of mating with larger males. Large males produced larger ejaculates than small males. Both males and females lost body weight as a consequence of breeding, and large males lost more weight than small males. The amount of

  1. Stochastic Modeling of Soft Magnetic Properties of Electrical Steels: Application to Stators of Electrical Machines

    E-print Network

    Paris-Sud XI, Université de

    1 Stochastic Modeling of Soft Magnetic Properties of Electrical Steels: Application to Stators magnetic materials properties (magnetic behavior law, iron losses) during the manufacturing process an impact on the magnetic behavior law and iron losses of the considered material [30-33]. Therefore

  2. Effects of stator vanes on power coefficients of a zephyr vertical axis wind turbine

    Microsoft Academic Search

    K. Pope; V. Rodrigues; R. Doyle; A. Tsopelas; R. Gravelsins; G. F. Naterer; E. Tsang

    2010-01-01

    In this paper, numerical and experimental studies are presented to determine the operating performance and power output from a vertical axis wind turbine (VAWT). A k-? turbulence model is used to perform the transient simulations. The 3-D numerical predictions are based on the time averaged Spalart-Allmaras equations. A case study is performed for varying VAWT stator vane (tab) geometries of

  3. Position sensorless synchronous reluctance motor drive using the stator phase voltage third harmonic

    Microsoft Academic Search

    Liviu Kreindler; Antonio Testa; T.A. Lipo

    1993-01-01

    A direct field orientation controller for synchronous reluctance motors based on determination of the spiral position of the air gap flux from the third harmonic component of the stator phase voltages is presented. The control utilizes the spatial saturation harmonic components rotating at synchronous frequency that are generated in the air gap flux when the machine operates in a saturated

  4. EEMD-based wind turbine bearing failure detection using the generator stator current homopolar component

    E-print Network

    Boyer, Edmond

    EEMD-based wind turbine bearing failure detection using the generator stator current homopolar turbine generators for stationary and non stationary cases. Keyword: Wind turbine, induction generator on the installed equipment because they are hardly accessible or even inaccessible [1]. 1.1. Wind turbine failure

  5. Locating of leaks in water-cooled generator stator bars using perfluorocarbon tracers

    Microsoft Academic Search

    W. M. Loss; R. N. Dietz

    1991-01-01

    Water cooled stator bars in power plant generators often fail during the maintenance cycle due to water leakage. After the hydrogen pressure in the generator shell has been released water can leak through cracks in the copper and through the insulation. Leaking bars, but not the leaks themselves, are detected with so-called hi-pot'' (high potential) tests where direct electrical current

  6. Locating of leaks in water-cooled generator stator bars using perfluorocarbon tracers

    Microsoft Academic Search

    W. M. Loss; R. N. Dietz

    1991-01-01

    Water cooled stator bars in power plant generators often fail during the maintenance cycle due to water leakage. After the hydrogen pressure in the generator shell has been released water can leak through cracks in the copper and through the insulation. Leaking bars, but not the leaks themselves, are detected with so-called ``hi-pot`` (high potential) tests where direct electrical current

  7. Considerations of AC and DC testing of large electrical stator windings and components

    Microsoft Academic Search

    F. T. Emery

    2005-01-01

    This paper is written on the basis of recommendations in IEEE Std 95-2002. It is common practice to use both AC and DC power supplies for the high potential testing of large electrical generator stator windings. A much higher voltage, well above the machine operating voltage; is almost always used. This paper reviews the procedures, results and test aspects of

  8. Improved groundwall insulation for VPI'ed high voltage stator coils

    Microsoft Academic Search

    F. T. Emery; J. D. B. Smith

    1997-01-01

    Improved dielectric performance of VPI'ed high voltage stator coils has been developed through a mica paper tape improvement program. The objectives of the program were to develop a glass-backed mica tape with higher dielectric properties than commercially available mica tapes. Tapes with improved dielectric properties allow a reduction in coil groundwall thickness which improves the thermal performance which in turn

  9. Online acoustic emission monitoring of combustion turbines for compressor stator vane crack detection

    NASA Astrophysics Data System (ADS)

    Momeni, Sepandarmaz; Koduru, Jaya P.; Gonzalez, Miguel; Zarate, Boris; Godinez, Valery

    2013-03-01

    Combustion turbine components operate under extreme environmental conditions and are susceptible to failure. Turbine blades are the most susceptible components and need to be regularly inspected to assure their integrity. Undetected cracks on these blades may grow quickly due to the high fatigue loading to which they are subjected and eventually fail causing extensive damage to the turbine. Cracks in turbine blades can originate from manufacturing errors, impact damages or the due to corrosion from the aggressive environment in which they operate. The component most susceptible to failure in a combustion turbine is the mid-compressor blades. In this region, the blades experience the highest gradients in temperature and pressure. Cracks in the rotator blades can be detected by vibration monitoring; while, the stator vanes or blades cracking can only be monitored by Acoustic Emission (AE) method. The stator vanes are in contact with the external casing of the turbine and therefore, any acoustic emission activity from the blades can be captured non-intrusively by placing sensors on the turbine casing. The acoustic emission activity from cracks that are under fatigue loading is significantly higher than the background noise and hence can be captured and located accurately by a group of AE sensors. Using a total of twelve AE sensors per turbine, the crack generation and propagation in the stator vanes of the mid-compressor section is monitored continuously. The cracks appearing in the stator vanes is clearly identified and located by the AE sensors.

  10. Demagnetization fault detection by means of Hilbert Huang transform of the stator current decomposition in PMSM

    Microsoft Academic Search

    J. Rosero; L. Romeral; J. A. Ortega; J. C. Urresty

    2008-01-01

    This paper presents a study of the permanent magnet synchronous motor (PMSM) running under demagnetization. The simulation has been carried out by means of two dimensional (2-D) finite element analysis (FEA), and simulations results were compared with experimental results. The demagnetization fault is analyzed by means of decomposition of stator currents obtained at different speeds for torque change.

  11. Sensorless PMSM drive with a sliding mode control based adaptive speed and stator resistance estimator

    Microsoft Academic Search

    Yoon-Seok Han; Jung-Soo Choi; Young-Seok Kim

    2000-01-01

    This paper presents a new speed and position sensorless control method of permanent magnet synchronous motors based on the sliding mode observer. The sliding mode observer structure and its design method are described. Also, Lyapunov functions are chosen for determining the adaptive law for the speed and the stator resistance estimator. The effectiveness of the proposed observer is confirmed by

  12. An On-line Method for Stator Fault Detection in Multi-phase PMSM Drives

    E-print Network

    Paris-Sud XI, Université de

    An On-line Method for Stator Fault Detection in Multi-phase PMSM Drives Fabien Meinguet*, Eric deals with an on-line fault detection method for multi-phase PMSM drives. The method is based an original method for detecting an abnormal asymmetrical behavior in five-phase PMSM drives and we apply

  13. Coupled magnetic circuit method and permeance network method modeling of stator faults in induction machines

    Microsoft Academic Search

    Amin Mahyob; Mohamed Y. Ould Elmoctar; Pascal Reghem; Georges Barakat

    2008-01-01

    The aim of this paper is to present and compare two modeling methods of the inter-turn short circuit fault in the stator winding of a cage induction machine. The first method is a Coupled Magnetic Circuit Method (CMCM) and the second method is a Permeance Network Method (PNM) which allows taking into account the saturation effect on the fault signature.

  14. Implications for the application of adjustable speed drive electronics to motor stator winding insulation

    Microsoft Academic Search

    J. A. Oliver; G. C. Stone

    1995-01-01

    Medium voltage (2300V to 4160V) motor stator insulation has been designed to withstand voltage surges from circuit breaker operation for many decades. It is probable that the surges created by ASDs will not pose a threat to properly designed and manufactured insulation. However, as ASDs become more popular in the higher voltage ranges, we will have to watch carefully to

  15. The use of cowl camber and taper to reduce rotor\\/stator interaction noise

    Microsoft Academic Search

    R. Martinez

    1995-01-01

    The project had two specific technical objectives: (1) to develop a realistic three-dimensional model of tonal noise due to rotor\\/stator interaction, as the input field for predictions of diffraction and dissipation by a lined cowl; and (2) to determine whether the generator curve of that cowl, or duct, could be 'steered' to yield substantially lower values of propulsor noise along

  16. Voltage distribution in stator windings of the motor driven by PWM inverter

    Microsoft Academic Search

    Wan Jianru; Liu Hongchi; Yu Huajun

    2002-01-01

    Based on the distributed parameters circuit model of motor windings, time domain analysis is applied to get the function of the winding voltage that depends on time, voltage input and location of each turn. The software ANSYS for Finite Element Analysis (FEA) is used to analyze the electromagnetic field in stator slots of the motor. A model of a single

  17. Effect of Paralleling the Stator Coils in a Permanent-Magnet Machine

    Microsoft Academic Search

    Mohammad S. Islam; Sayeed Mir; Tomy Sebastian

    2006-01-01

    As low-voltage machines require smaller number of turns per phase compared to higher voltage machines, it is normal to connect the various stator phase coils in parallel to form the phase winding. The placement of various coil sides in the slot and the difference in the field produced by different poles of the rotor magnet can influence the induced voltage

  18. The global responses characteristics of a rotor/stator rubbing system with dry friction effects

    NASA Astrophysics Data System (ADS)

    Shang, Zhiyong; Jiang, Jun; Hong, Ling

    2011-05-01

    Rotor/stator rubbing systems may undertake a number of quite different responses. Recent experiments on rotor/stator rubbing have revealed that two or three different responses may coexist. In this paper the global response characteristics of a general rotor/stator rubbing system, which takes into account the dominant factors in the process of rotor/stator rubbing, especially, the dry friction effect that is mostly neglected in the previous works and is the main factor for the self-excited dry friction backward whirl, are studied. The different solutions of the piecewise nonlinear system are derived and their stability are analyzed to get the existence boundaries of the different responses. An overall picture of the global response characteristics of this model is then obtained by drawing the existence boundaries in a same parameter space. The present results provide good understanding on the coexistence of different rubbing responses observed in tests. Moreover, deeper insight into the types of coexistence of different rubbing responses and their relationship with the system parameters is gained.

  19. In-service evaluation of motor and generator stator windings using partial discharge tests

    Microsoft Academic Search

    Greg C. Stone; Howard G. Sedding

    1995-01-01

    Partial discharges (corona) are a symptom of most types of deterioration of motor and generator stator windings rated 4 kV and above. Experience indicates that partial discharges occur years before failure. This leaves sufficient time to plan corrective maintenance to avoid the in-service failure of the motor or generator. This paper describes a new type of partial discharge test which

  20. Implementation of direct stator flux orientation control on a versatile DSP based system

    Microsoft Academic Search

    Xingyi Xu; Donald W. Novotny

    1991-01-01

    The implementation of direct stator flux orientation (DSFO) control for induction machines on a versatile Motorola 56000 digital signal processor (DSP) based system is described. Some practical aspects of implementing DSFO control, such as parameter identification, flux estimation, and rotor angular velocity estimation, are discussed. Experimental results are presented to show the performance of a DSFO-controlled induction machine drive. Comparison

  1. Study of Tip-Clearance Flow and Stator-Rotor Interaction Using Large-Eddy Simulation

    Microsoft Academic Search

    D. You; R. Mittal; M. Wang; P. Moin

    2000-01-01

    In liquid handling systems like pumps, low pressure fluctuations downstream of the rotor can induce cavitation which can sometimes lead to undesirable acoustic noise. It has been hypothesized that both the ``cutting'' of the stator wakes by the rotor, and the tip-leakage flow are together responsible for these low pressure fluctuations. In order to analyze the temporal dynamics of this

  2. Analysis of Optimal Stator Concentric Winding Patterns University of Wisconsin-Madison

    E-print Network

    Lipo, Thomas

    #12;1 Abstract -- Most small induction motors in current use employ concentric windings which have Motive Force (MMF) harmonics of electrical machine created by the stator concentric windings for uniform air-gap machines. By evaluating the harmonic property of the synthesized three phase air gap MMF

  3. A Modeling Approach for Gearbox Monitoring Using Stator Current Signature in Induction Machines

    Microsoft Academic Search

    Shahin Hedayati Kia; Humberto Henao; Gérard-André Capolino

    2008-01-01

    The gearbox monitoring using motor current signature analysis has been rarely proposed while gearboxes are widely used in the industrial applications and they are subjected to progressive deterioration. In this paper, a simple dynamic model of a single stage gearbox is used to show accurately the effect of the rotating input, output and mesh frequency components in the stator current

  4. Design and Experimental Investigation of a Single-stage Turbine with a Downstream Stator

    NASA Technical Reports Server (NTRS)

    Plohr, Henry W; Holeski, Donald E; Forrette, Robert E

    1957-01-01

    The high-work-output turbine had an experimental efficiency of 0.830 at the design point and a maximum efficiency of 0.857. The downstream stator was effective in providing axial flow out of the turbine for almost the whole range of turbine operation.

  5. A survey of testing and monitoring methods for stator insulation systems in induction machines

    Microsoft Academic Search

    S. Grubic; J. M. Aller; B. Lu; T. G. Habetler

    2008-01-01

    A breakdown of the electrical insulation system causes catastrophic failure of the electrical machine and brings large process downtime losses. To determine the conditions of the stator insulation system of motor drive systems, various testing and monitoring methods have been developed. This paper presents an in-depth literature review of more than 20 existing methods, including the most common methods to

  6. CURRENT COMMUTATION ANALYSIS IN SELF-CONTROLLED DOUBLE STATOR SYNCHRONOUS MACHINES TAKING INTO ACCOUNT SATURATION EFFECT

    Microsoft Academic Search

    A. KHELOUI; F. MEIBODY-TABAR; B. DAVAT

    1995-01-01

    In the field of high power drives, the double armature synchronous machines constitute an advantageous choice compared to classical synchronous machines, because of the relatively low torque ripple produced. This paper proposes an analytical model of the current commutation and its influence on pulsating torque, in converter fed Double Stator Synchronous Machines (DSSM), taking into account the magnetic saturation with

  7. Traveling-wave piezoelectric linear motor Part I: the stator design.

    PubMed

    Ting, Yung; Chen, Liang-Chiang; Li, Chun-Chung; Huang, Jeng-Lin

    2007-04-01

    A new type of piezoelectric linear motor incorporating a traveling wave has been developed. The linear motor is comprised of a stator and a carriage. The stator design, which consists of a meander-line structure and gear teeth mounted on the meander-line structure, is the focus of this article. The meander-line structure is constructed with bimorph actuators arranged in a line. These actuators are driven by two phased sets of alternating current (ac) in order to generate a traveling wave. The traveling wave is transferred to the gear teeth, by which the carriage is driven. Modeling of the stator is derived by use of a strain energy method. The performance of various materials is evaluated by analytical and experimental methods. The analytical and the experimental results are quite approximate. Modal analysis is investigated using ANSYS. Appropriate modes associated with ultrasonic levels of resonant frequency are selected to obtain desired motion and to enhance the output performance. Surface speed for various applied input voltage are studied and indicate a nearly linear relationship. The stator in combination with the carriage makes up the linear motor. PMID:17441594

  8. Numerical investigation of the superimposed effects on stator wake oscillation in an axial-radial combined compressor

    NASA Astrophysics Data System (ADS)

    Zhao, Ben; Yang, Ce; Hu, Liangjun; Zhou, Mi; Zhang, Jizhong

    2014-02-01

    The superimposed influences of the blade rows in a multistage compressor are important because different matches of upstream and downstream blades can result in significant differences in the stator wake oscillation. Numerical investigation of the axial stator wake oscillation, which is affected upstream by the axial rotor and downstream by the radial rotor, was performed in an axial-radial combined compressor. Many configurations with different blade numbers and locations, which influence axial stator wake oscillation were investigated. When rotors have equal blade numbers, the axial stator wake oscillates periodically versus time within time T (moving blade passing 1/3 revolution). In contrast, stator wake oscillates irregularly within T when rotors have different blade numbers. A model-split subtraction method is presented in order to separate the influences of the individual blade rows on the wake oscillation of the axial stator. Analysis from the rotor-stator configuration showed that the unsteady flow angle fluctuation response is caused by the upstream rotor. For the rotor-stator-rotor configuration, the unsteady flow angle fluctuations are influenced by up- and downstream blade rows. With the model-split subtraction method, the up- and downstream influences on the flow angle fluctuation could be clearly separated and quantified. Low amplitudes could be observed when the influences from up- and downstream moving rows were superimposed with the "positive peak-negative peak" type wave. Clocking investigations were carried out to change the relative superimposed phase of influences from the surrounding blade rows in order to modulate the amplitudes of the axial stator wake oscillation. However, the amplitudes did not reach the maximum when they were superimposed with "positive peak-positive peak" type wave due to the impact of the interaction between the two moving blade rows.

  9. Performance of a high-work, low-aspect-ratio turbine stator tested with a realistic inlet radial temperature gradient

    NASA Technical Reports Server (NTRS)

    Stabe, Roy G.; Schwab, John R.

    1991-01-01

    A 0.767-scale model of a turbine stator designed for the core of a high-bypass-ratio aircraft engine was tested with uniform inlet conditions and with an inlet radial temperature profile simulating engine conditions. The principal measurements were radial and circumferential surveys of stator-exit total temperature, total pressure, and flow angle. The stator-exit flow field was also computed by using a three-dimensional Navier-Stokes solver. Other than temperature, there were no apparent differences in performance due to the inlet conditions. The computed results compared quite well with the experimental results.

  10. An online identification method for both stator resistance and back-EMF coefficient of PMSMs without rotational transducers

    Microsoft Academic Search

    Kyu-Wang Lee; Doo-Hee Jung; In-Joong Ha

    2004-01-01

    This letter describes an effective online method for identifying both the stator resistance and the back-electromotive-force (EMF) coefficient of a permanent-magnet synchronous motor (PMSM) without rotational transducers. Using only the information of stator currents and voltages, it can provide fairly good identification accuracy under various load conditions and can be easily incorporated into most sensorless speed control schemes proposed in

  11. Comparison Between Stator Current and Estimated Mechanical Speed for the Detection of Bearing Wear in Asynchronous Drives

    Microsoft Academic Search

    Baptiste Trajin; Jeremi Regnier; Jean Faucher

    2009-01-01

    This paper deals with the detection of worn rolling bearings in asynchronous machines using electrical measurements and estimated mechanical variables. These two approaches are based on the use of the available electrical quantities, e.g., the machine stator currents, which are often already measured for control and protection purposes. Considering that bearing faults induce load-torque oscillations, a theoretical stator-current model, in

  12. Insulation failure detection in the stator windings of ASD-driven induction machines using standard deviation of line currents

    Microsoft Academic Search

    M. Alex Cash; Thomas G. Habetler

    1998-01-01

    This paper develops a straightforward, current-based scheme to detect stator turn faults that have occurred due to insulation failure in an ASD-driven, three-phase induction machine. The method employs simple statistical analysis to detect turn shorts in the stator of the machine. It is shown that the standard deviation of the calibrated, RMS line currents reveals a change in the machine's

  13. Dual stator winding variable speed asynchronous generator: optimal design and experiments

    NASA Astrophysics Data System (ADS)

    Tutelea, L. N.; Deaconu, S. I.; Popa, G. N.

    2015-06-01

    In the present paper is carried out a theoretical and experimental study of dual stator winding squirrel cage asynchronous generator (DSWA) behavior in the presence of saturation regime (non-sinusoidal) due to the variable speed operation. The main aims are the determination of the relations of calculating the equivalent parameters of the machine windings to optimal design using a Matlab code. Issue is limited to three phase range of double stator winding cage-induction generator of small sized powers, the most currently used in the small adjustable speed wind or hydro power plants. The tests were carried out using three-phase asynchronous generator having rated power of 6 [kVA].

  14. Three-dimensional Navier-Stokes simulations of turbine rotor-stator interaction

    NASA Technical Reports Server (NTRS)

    Rai, Man Mohan

    1988-01-01

    Fluid flows within turbomachinery tend to be extremely complex in nature. Understanding such flows is crucial to improving current designs of turbomachinery. The computational approach can be used to great advantage in understanding flows in turbomachinery. A finite difference, unsteady, thin layer, Navier-Stokes approach to calculating the flow within an axial turbine stage is presented. The relative motion between the stator and rotor airfoils is made possible with the use of patched grids that move relative to each other. The calculation includes endwall and tip leakage effects. An introduction to the rotor-stator problem and sample results in the form of time averaged surface pressures are presented. The numerical data are compared with experimental data and the agreement between the two is found to be good.

  15. Effect of Stator and Rotor Aspect Ratio on Transonic-Turbine Performance

    NASA Technical Reports Server (NTRS)

    Wong, Robert Y.; Monroe, Daniel E.

    1959-01-01

    The effect of stator and rotor aspect ratio on transonic-turbine performance was experimentally investigated. The stator aspect ratios covered were 1.6. 0.8, and 0.4, while the rotor aspect ratios investigated were 1.46 and 0.73. It was found that the observed variation in turbine design-point efficiency was negligible. Thus, within the range of aspect ratio investigated, these results verify for turbines operating in the transonic flow range the finding of a reference report, which showed analytically that, if blade shape and solidity are held constant, the aspect ratio may be varied over a wide range without appreciable change in turbine efficiency.

  16. Dynamics of the Bacterial Flagellar Motor: The Effects of Stator Compliance, Back Steps, Temperature, and Rotational Asymmetry

    PubMed Central

    Meacci, Giovanni; Lan, Ganhui; Tu, Yuhai

    2011-01-01

    The rotation of a bacterial flagellar motor (BFM) is driven by multiple stators tethered to the cell wall. Here, we extend a recently proposed power-stroke model to study the BFM dynamics under different biophysical conditions. Our model explains several key experimental observations and reveals their underlying mechanisms. 1), The observed independence of the speed at low load on the number of stators is explained by a force-dependent stepping mechanism that is independent of the strength of the stator tethering spring. Conversely, without force-dependent stepping, an unrealistically weak stator spring is required. 2), Our model with back-stepping naturally explains the observed absence of a barrier to backward rotation. Using the same set of parameters, it also explains BFM behaviors in the high-speed negative-torque regime. 3), From the measured temperature dependence of the maximum speed, our model shows that stator-stepping is a thermally activated process with an energy barrier. 4), The recently observed asymmetry in the torque-speed curve between counterclockwise- and clockwise-rotating BFMs can be quantitatively explained by the asymmetry in the stator-rotor interaction potentials, i.e., a quasilinear form for the counterclockwise motor and a quadratic form for the clockwise motor. PMID:21504735

  17. Fourier and Wavelet Transformations for the Fault Detection of Induction Motor with Stator Current

    Microsoft Academic Search

    Sang-hyuk Lee; Seong-pyo Cheon; Youn Tae Kim; Sungshin Kim

    2006-01-01

    \\u000a In this literature, fault detection of an induction motor is carried out using the information of stator current. After preprocessing\\u000a actual data, Fourier and Wavelet transforms are applied to detect characteristics under the healthy and various faulted conditions.\\u000a The most reliable phase current among 3-phase currents is selected by the fuzzy entropy. Data are trained with a neural network\\u000a system,

  18. Fourier and wavelet transformations application to fault detection of induction motor with stator current

    Microsoft Academic Search

    Sang-hyuk Lee; Yi-qi Wang; Jung-il Song

    2010-01-01

    Fault detection of an induction motor was carried out using the information of the stator current. After synchronizing the\\u000a actual data, Fourier and wavelet transformations were adopted in order to obtain the sideband or detail value characteristics\\u000a under healthy and various faulty operating conditions. The most reliable phase current among the three phase currents was\\u000a selected using an approach that

  19. Fourier and Wavelet Transformations for the Fault Detection of Induction Motor with Stator Current

    Microsoft Academic Search

    Sang-Hyuk Lee; Seong-Pyo Cheon; Yountae Kim; Sungshin Kim

    \\u000a In this literature, fault detection of an induction motor is carried out using the information of stator current. After preprocessing\\u000a actual data, Fourier and Wavelet transforms are applied to detect characteristics under the healthy and various faulted conditions.\\u000a The most reliable phase current among 3-phase currents is selected by the fuzzy entropy. Data are trained with a neural network\\u000a system,

  20. Effect of surge testing on unimpregnated ground insulation of VPI stator coils

    Microsoft Academic Search

    Meredith K. W. Stranges; David A. Snopek; A. Karim Younsi; James H. Dymond

    2002-01-01

    The IEEE 522 guide for testing turn-to-turn insulation in form wound coils for alternating-current machines is currently under working group review, with the intent to eliminate problems in interpretation and application. The guide is written for the testing of fully processed coils, while the motor industry uses the test guide for pre-impregnated vacuum-pressure-impregnated coils wound in the stator core. The

  1. MV generator low-resistance grounding and stator ground fault damage

    Microsoft Academic Search

    Alex Wu; Yousin Tang; Dale Finney

    2004-01-01

    Most of the in-plant medium-voltage generators are grounded through resistors ranging from 200 to 400 A. In some unusual situations, the resistors may even be as high as 1200 A. Low-resistance grounding is a preferred choice for a medium-voltage power distribution system. However, extensive generator stator ground fault damages had been reported due to the prolonging generator neutral ground current,

  2. Locating of leaks in water-cooled generator stator bars using perfluorocarbon tracers

    SciTech Connect

    Loss, W.M.; Dietz, R.N.

    1991-09-01

    Water cooled stator bars in power plant generators often fail during the maintenance cycle due to water leakage. After the hydrogen pressure in the generator shell has been released water can leak through cracks in the copper and through the insulation. Leaking bars, but not the leaks themselves, are detected with so-called hi-pot'' (high potential) tests where direct electrical current is applied to the stator bar windings. A study initiated by ConEd and Brookhaven's Tracer Technology Center to explore the cause of these leakage problems to determine if the failures originate in the manufacturing process or are created in service by phase related torque stresses. To this purpose bars that had failed the hi-pot test were investigated first with the insulation in place and then stripped to the bare copper. The bars were pressurized with gases containing perfluorocarbon tracers and the magnitude and location of the leaks was detected by using tracers technology principles and instruments such as the double source'' method and the Dual Trap Analyzer. In the second part of the project the windings within a generator were tested in-situ for leaks during an outage using tracer principles. Recommendations are given suggesting the shut down of stator bar cooling water before hydrogen bleeding during outages and a revision of the current vent flow rate. The new standard should establish a reasonable leak rate for the stator bar windings proper and exclude leakage of pump seals and connections. Testing during the maintenance cycle in generators should include routine tracer leak detection following the hi-pot test.

  3. Locating of leaks in water-cooled generator stator bars using perfluorocarbon tracers

    SciTech Connect

    Loss, W.M.; Dietz, R.N.

    1991-09-01

    Water cooled stator bars in power plant generators often fail during the maintenance cycle due to water leakage. After the hydrogen pressure in the generator shell has been released water can leak through cracks in the copper and through the insulation. Leaking bars, but not the leaks themselves, are detected with so-called ``hi-pot`` (high potential) tests where direct electrical current is applied to the stator bar windings. A study initiated by ConEd and Brookhaven`s Tracer Technology Center to explore the cause of these leakage problems to determine if the failures originate in the manufacturing process or are created in service by phase related torque stresses. To this purpose bars that had failed the hi-pot test were investigated first with the insulation in place and then stripped to the bare copper. The bars were pressurized with gases containing perfluorocarbon tracers and the magnitude and location of the leaks was detected by using tracers technology principles and instruments such as the ``double source`` method and the Dual Trap Analyzer. In the second part of the project the windings within a generator were tested in-situ for leaks during an outage using tracer principles. Recommendations are given suggesting the shut down of stator bar cooling water before hydrogen bleeding during outages and a revision of the current vent flow rate. The new standard should establish a reasonable leak rate for the stator bar windings proper and exclude leakage of pump seals and connections. Testing during the maintenance cycle in generators should include routine tracer leak detection following the hi-pot test.

  4. Rotor-mounted scanning of stators in hydro and turbine-drive generators

    Microsoft Academic Search

    Thomas L. Churchill; James S. Edmonds; C. W. Burns

    1991-01-01

    Comprehensive rotor-mounted scanning of hydrogenerator stators has attained commercial status on the basis of prototype development and extensive beta-site testing on four generators and two pumped-storage units ranging in capacity from 22 to 450 MVA. Thermal, RFI, acoustic, air-gap, magnetic, and rotor vibration sensors are monitored in real-time to provide early warning of impending failures. Resulting data are continuously processed

  5. Diagnosis of continuous rotor–stator rubbing in large scale turbine units using acoustic emissions

    Microsoft Academic Search

    L. D. Hall

    2004-01-01

    Continuous rubbing between the shaft and surrounding seals or end-glands of electricity generating turbine units can escalate into very severe vibration and costly rotor damage. Therefore such rotor–stator contacts require early diagnosis so as to minimize the financial consequences of any unplanned shutdowns. Acoustic emissions (AEs) or stress wave monitoring at the bearings has been identified as a sensitive non-destructive

  6. Two flagellar stators and their roles in motility and virulence in Pseudomonas syringae pv. tabaci 6605

    Microsoft Academic Search

    Eiko Kanda; Takafumi Tatsuta; Tomoko Suzuki; Fumiko Taguchi; Kana Naito; Yoshishige Inagaki; Kazuhiro Toyoda; Tomonori Shiraishi; Yuki Ichinose

    2011-01-01

    The motor proteins around the flagellar basal body consist of two cytoplasmic membrane proteins, MotA and MotB, and function\\u000a as a complex that acts as the stator to generate the torque that drives rotation. Genome analysis of several Pseudomonas syringae pathovars revealed that there are two sets of genes encoding motor proteins: motAB and motCD. Deduced amino acid sequences for

  7. Stator flux orientation control of induction machines in the field weakening region

    Microsoft Academic Search

    X. Xu; R. de Doncker; D. W. Novotny

    1988-01-01

    The behavior of a director stator-flux-oriented (SFO) system in the field weakening region is studied and compared with that of a direct rotor-flux-oriented (RFO) system. The steady-state analysis shows that the SFO system always retains maximum torque capability, not matter how large the error in the parameters. In contrast, RFO is sensitive to variations in leakage and magnetizing inductances. When

  8. An online stator winding resistance estimation technique for temperature monitoring of line-connected induction machines

    Microsoft Academic Search

    Sang-Bin Lee; Thomas G. Habetler

    2003-01-01

    A new technique for stator-resistance (Rs)-based thermal monitoring of small line-connected induction machines is proposed in this paper. A simple device is developed for injecting a small DC signal into line-connected induction machines for estimation of Rs. The proposed DC injection device is capable of intermittently injecting a controllable DC bias into the motor with very low power dissipation. Experimental

  9. Instantaneous magnetic field distribution in brushless permanent magnet DC motors. III. Effect of stator slotting

    Microsoft Academic Search

    Z. Q. Zhu; D. Howe

    1993-01-01

    For pt.II see ibid., vol.29, no.1, p.136-142 (1993). A method for modeling the effect of stator slotting on the magnetic field distribution in the airgap\\/magnet region of a radial-field brushless permanent-magnet DC motor equipped with a surface-mounted magnet rotor is presented to allow the analytical prediction of the open-circuit, armature-reaction, and consultant magnetic field distribution under any specified load condition.

  10. Unsteady flow investigation in rotor-stator interface of a radial diffuser pump

    Microsoft Academic Search

    Jianjun Feng; F. K. Benra; H. J. Dohmen

    2010-01-01

    The flow in a vaned diffuser radial pump is fully turbulent and strongly unsteady, caused by the rotor-stator interaction.\\u000a In this paper, two-dimensional laser Doppler velocimetry (LDV) measurement results have been utilized to investigate the unsteady\\u000a flow in a low specific speed radial diffuser pump with leaning impeller trailing edges. CFD simulations have been also conducted\\u000a to provide more extensive

  11. Nonlinear analysis of a permanent magnet synchronous machine with nonsinusoidal stator winding currents

    Microsoft Academic Search

    M. V. K. Chari; J. D’Angelo; G. Bedrosian; T. W. Neumann

    1985-01-01

    Permanent magnet synchronous machines and induction motors are often required to operate on-line starting or inverter-fed systems, which results in nonsinusoidal stator currents. These, in turn, give rise to undesirable harmonics and power losses which degrade motor performance. In this paper a time-domain analysis is presented for evaluating the magnetic field distribution in the two-dimensional cross section of the machine

  12. A nickel base alloy, NASA WAZ-16, with potential for gas turbine stator vane application

    NASA Technical Reports Server (NTRS)

    Waters, W. J.; Freche, J. C.

    1974-01-01

    A nickel-base superalloy based on the nickel-aluminum-tungsten system designated WAZ-16 was developed for high strength in the 1095 C (2000 F) to 1205 C (2200 F) range. Its tensile strength at the latter temperature is approximately 186 MN/m2 (27,000 psi). The combination of properties of the alloy suggest that it has potential as a stator vane material in advanced gas turbine engines.

  13. Blade-forced vibration effects in turbomachinery rotor-stator interaction

    E-print Network

    Collard, Joseph Eugene

    2000-01-01

    OF FIGURES FIGURE Page Rai's system of patched and overlaid grids. Shearing quadri]ateral cells at unsteady stator/rotor interface. . . . . 4 The computational domain broken up into inner and outer regions. . 8 An example of patched-grids. An example... becomes very distorted and may produce inaccurate solutions. To resolve this, a system of patched and overlaid grids, Fig. 1, was developed by Rai [11] and R, ai and Madavan [12] to discretize thc flow field surrounding the rotating and stationary...

  14. Detection of outer raceway bearing defects in small induction motors using stator current analysis

    Microsoft Academic Search

    ?zzet Y. önel; K. Burak Dalci; ?brahim Senol

    2005-01-01

    We investigate the application of induction motor stator current spectral analysis (MCSA) for detection of rolling element\\u000a bearing damage from the outer raceway. In this work, MCSA and vibration analysis are applied to induction motor to detect\\u000a outer raceway defects in faulty bearings. Data acquisition, recording, and fast fourier transform (FFT) algorithms are done\\u000a by using the Lab VIEW programming

  15. Periodic transition on an axial compressor stator: Incidence and clocking effects. Part 1: Experimental data

    SciTech Connect

    Walker, G.J.; Hughes, J.D. [Univ. of Tasmania, Hobart (Australia). School of Engineering; Solomon, W.J. [Ohio Aerospace Institute/General Electric Aircraft Engines, Cincinnati, OH (United States)

    1999-07-01

    Periodic wake-induced transition on the outlet stator of a 1.5-stage axial compressor is examined using hot-film arrays on both the suction and pressure surfaces. The time-mean surface pressure distribution is varied by changing the blade incidence, while the free-stream disturbance field is altered by clocking of the stator relative to an inlet guide vane row. Ensemble-averaged plots of turbulent intermittency and relaxation factor (extent of calmed flow following the passage of a turbulent spot) are presented. These show the strength of periodic wake-induced transition phenomena to be significantly influenced by both incidence and clocking effects. The nature and extent of transition by other modes (natural, bypass, and separated flow transition) are altered accordingly. Leading edge and midchord separation bubbles are affected in a characteristically different manner by changing free-stream periodicity. There are noticeable differences between suction and pressure surface transition behavior, particularly as regards the strength and extent of calming. In Part 2 of this paper, the transition onset observations from the compressor stator are used to evaluate the quasi-steady application of conventional transition correlations to predict unsteady transition onset on the blading of an embedded axial compressor stage.

  16. Acoustic Reflection and Transmission of 2-Dimensional Rotors and Stators, Including Mode and Frequency Scattering Effects

    NASA Technical Reports Server (NTRS)

    Hanson, Donald B.

    1999-01-01

    A reduced order modeling scheme has been developed for the unsteady acoustic and vortical coupling between blade rows of a turbomachine. The essential behavior of the system is governed by modal scattering coefficients (i.e., reflection and transmission coefficients) of the rotor, stator, inlet and nozzle, which are calculated as if they were connected to non-reflecting ducts. The objective of this report is to identify fundamental behavior of these scattering coefficients for a better understanding of the role of blade row reflection and transmission in noise generation. A 2D flat plate unsteady cascade model is used for the analysis with the expectation that the general behavior presented herein will carry over to models that include more realistic flow and geometry. It is shown that stators scatter input waves into many modes at the same frequency whereas rotors scatter on frequency, or harmonic order. Important cases are shown here the rotor reflection coefficient is greater than unity; a mode at blade passing frequency (BPF) traveling from the stator with unit sound power is reflected by the rotor with more than unit power at 2xBPF and 3xBPE Analysis is presented to explain this unexpected phenomenon. Scattering curves are presented in a format chosen for design use and for physical interpretation. To aid in interpretation of the curves, formulas are derived for special condition where waveforms are parallel to perpendicular to the rotor.

  17. Active Flow Separation Control of a Stator Vane Using Surface Injection in a Multistage Compressor Experiment

    NASA Technical Reports Server (NTRS)

    Culley, Dennis E.; Bright, Michelle M.; Prahst, Patricia S.; Strazisar, Anthony J.

    2003-01-01

    Micro-flow control actuation embedded in a stator vane was used to successfully control separation and improve near stall performance in a multistage compressor rig at NASA Glenn. Using specially designed stator vanes configured with internal actuation to deliver pulsating air through slots along the suction surface, a research study was performed to identify performance benefits using this microflow control approach. Pressure profiles and unsteady pressure measurements along the blade surface and at the shroud provided a dynamic look at the compressor during microflow air injection. These pressure measurements lead to a tracking algorithm to identify the onset of separation. The testing included steady air injection at various slot locations along the vane. The research also examined the benefit of pulsed injection and actively controlled air injection along the stator vane. Two types of actuation schemes were studied, including an embedded actuator for on-blade control. Successful application of an online detection and flow control scheme will be discussed. Testing showed dramatic performance benefit for flow reattachment and subsequent improvement in diffusion through the use of pulsed controlled injection. The paper will discuss the experimental setup, the blade configurations, and preliminary CFD results which guided the slot location along the blade. The paper will also show the pressure profiles and unsteady pressure measurements used to track flow control enhancement, and will conclude with the tracking algorithm for adjusting the control.

  18. Measurement of attitude angles of single stator multi-degrees of freedom ultrasonic motor

    NASA Astrophysics Data System (ADS)

    Liu, Wu-fal; Tao, Zheng; Zhang, Lin-na; Gao, Jian-she; Zhao, Feng-xia; Zhen, Peng

    2010-08-01

    In order to measure the attitude angles of our ultrasonic motor, a compact single stator multi-degree-of freedom (DOF) ultrasonic motor with a cylindrical stator and a spherical rotor is designed with one OEM encoder and 2D PSD (Position Sensitive Detector) sensor. The spherical rotor is rotated around three perpendicular axes by three natural vibrations excited on the stator. The OEM encoder disc is fixed on the rotor output shaft to measure the rotational angle of the output shaft. The PSD sensor is installed in loading sphere, and one LED is installed in the LED house, the line light emitted by the LED transmits along the output shaft axis and passes through the center of the spherical rotor, and then projects on the PSD surface, and the PSD and LED comprise the device to measure the pitch and roll of the rotor. The output current signals of the PSD sensor are changed into voltages, amplified by measuring circuits, converted into digital signals, and are transmitted to MCU. The attitude angles of the motor are calculated out using the proposed algorithm. The compact structure design of the motor makes the measurement of the attitude angles of the multi-DOF ultrasonic motor more practical and convenient.

  19. Aerodynamic performances of three fan stator designs operating with rotor having tip speed of 337 meters per second and pressure ratio of 1.54. 1: Experimental performance

    NASA Technical Reports Server (NTRS)

    Gelder, T. F.

    1980-01-01

    The aerodynamic performances of four stator-blade rows are presented and evaluated. The aerodynamic designs of two of these stators were compromised to reduce noise, a third design was not. On a calculated operating line passing through the design point pressure ratio, the best stator had overall pressure-ratio and efficiency decrements of 0.031 and 0.044, respectively, providing a stage pressure ratio of 1.483 and efficiency of 0.865. The other stators showed some correctable deficiencies due partly to the design compromises for noise. In the end-wall regions blade-element losses were significantly less for the shortest chord studied.

  20. Influence of inlet nozzle on secondary flow in axial stator blade cascade

    NASA Astrophysics Data System (ADS)

    Straka, Petr; Šimák, Jan; Pelant, Jaroslav

    2014-08-01

    This paper deals with numerical modelling of a turbulent compressible flow through an axial stator blade cascade. An attention is paid to the influence of the geometry of the inlet nozzle on the secondary flows in the blade cascade. The flow-field is divided on two parts: inlet nozzle, where a model of a 2D axisymmetric flow is used and the blade cascade, which is solved by a model of a fully 3D flow. The connection of the 2D axisymmetric model and the fully 3D model is proposed in this work.

  1. Predicting the Rotor-Stator Interaction Acoustics of a Ducted Fan Engine

    NASA Technical Reports Server (NTRS)

    Biedron, Robert T.; Rumsey, Christopher L.; Podboy, Gary G.; Dunn, M. H.

    2001-01-01

    A Navier-Stokes computation is performed for a ducted-fan configuration with the goal of predicting rotor-stator noise generation without having to resort to heuristic modeling. The calculated pressure field in the inlet region is decomposed into classical infinite-duct modes, which are then used in either a hybrid finite-element/Kirchhoff surface method or boundary integral equation method to calculate the far field noise. Comparisons with experimental data are presented, including rotor wake surveys and far field sound pressure levels for two blade passage frequency (BPF) tones.

  2. Three-dimensional Euler time accurate simulations of fan rotor-stator interactions

    NASA Technical Reports Server (NTRS)

    Boretti, A. A.

    1990-01-01

    A numerical method useful to describe unsteady 3-D flow fields within turbomachinery stages is presented. The method solves the compressible, time dependent, Euler conservation equations with a finite volume, flux splitting, total variation diminishing, approximately factored, implicit scheme. Multiblock composite gridding is used to partition the flow field into a specified arrangement of blocks with static and dynamic interfaces. The code is optimized to take full advantage of the processing power and speed of the Cray Y/MP supercomputer. The method is applied to the computation of the flow field within a single stage, axial flow fan, thus reproducing the unsteady 3-D rotor-stator interaction.

  3. Low Speed, 2-D Rotor/Stator Active Noise Control at the Source Demonstration

    NASA Technical Reports Server (NTRS)

    Simonich, John C.; Kousen, Ken A.; Zander, Anthony C.; Bak, Michael; Topol, David A.

    1997-01-01

    Wake/blade-row interaction noise produced by the Annular Cascade Facility at Purdue University has been modeled using the LINFLO analysis. Actuator displacements needed for complete cancellation of the propagating acoustic response modes have been determined, along with the associated actuator power requirements. As an alternative, weighted least squares minimization of the total far-field sound power using individual actuators has also been examined. Attempts were made to translate the two-dimensional aerodynamic results into three-dimensional actuator requirements. The results lie near the limit of present actuator technology. In order to investigate the concept of noise control at the source for active rotor/stator noise control at the source, various techniques for embedding miniature actuators into vanes were examined. Numerous miniature speaker arrangements were tested and analyzed to determine their suitability as actuators for a demonstration test in the Annular Cascade Facility at Purdue. The best candidates demonstrated marginal performance. An alternative concept to using vane mounted speakers as control actuators was developed and tested. The concept uses compression drivers which are mounted externally to the stator vanes. Each compression driver is connected via a tube to an air cavity in the stator vane, from which the driver signal radiates into the working section of the experimental rig. The actual locations and dimensions of the actuators were used as input parameters for a LINFLO computational analysis of the actuator displacements required for complete cancellation of tones in the Purdue experimental rig. The actuators were designed and an arrangement determined which is compatible with the Purdue experimental rig and instrumentation. Experimental tests indicate that the actuators are capable of producing equivalent displacements greater than the requirements predicted by the LINFLO analysis. The acoustic output of the actuators was also found to be unaffected by the presence of air flow representative of the Purdue experimental rig. A test of the active noise control at the source concept for rotor/stator active noise control was demonstrated. This 2-D test demonstrated conclusively the simultaneous reduction of two acoustic modes. Reductions of over 10 dB were obtained over a wide operating range.

  4. Comparison of calculated and experimental cascade performance for controlled-diffusion compressor stator blading

    NASA Technical Reports Server (NTRS)

    Sanger, N. L.; Shreeve, R. P.

    1986-01-01

    The mid-span section of a previously reported controlled-diffusion compressor stator has been experimentally evaluated in cascade. Measurements are taken over a range of incidence angles for blade chord Reynolds numbers from 470,000 to 690,000. Blade chord length is 12.7 cm, aspect ratio is 2.0, and solidity is 1.67. Measurements include conventional cascade performance parameters as well as blade surface pressures. Computations are made for the inviscid flow field, surface boundary layers, and loss for several of the blade inlet angle conditions, are compared against corresponding data.

  5. Detection of stator winding faults in induction machines using flux and vibration analysis

    NASA Astrophysics Data System (ADS)

    Lamim Filho, P. C. M.; Pederiva, R.; Brito, J. N.

    2014-01-01

    This work aims at presenting the detection and diagnosis of electrical faults in the stator winding of three-phase induction motors using magnetic flux and vibration analysis techniques. A relationship was established between the main electrical faults (inter-turn short circuits and unbalanced voltage supplies) and the signals of magnetic flux and vibration, in order to identify the characteristic frequencies of those faults. The experimental results showed the efficiency of the conjugation of these techniques for detection, diagnosis and monitoring tasks. The results were undoubtedly impressive and can be adapted and used in real predictive maintenance programs in industries.

  6. Dynamic pressure and shear stress measurements on the stator wall of whirling annular seals 

    E-print Network

    Winslow, Robert Bradley

    1994-01-01

    , m, radial direction Reynolds number, 2pU c/tt Root mean square Shear stress, Pa Tc/(itW~) Time averaged non-dimensional shear stress Taylor number, (pW, ?c/tt)(2c/D)' Mean axial velocity, m/s U/U uu uu* V Average mean axial velocity, m... on the stator wall (at Z/L=0. 5), and the X, Y, and Z axes are defined. Figure 7: Non-dimensional, mean shear stress profiles for the 0/o eccentricity 33 seal. 101 Figure 8: Non-dimensional, mean shear stress profiles for the 10/o eccentricity seal. 102...

  7. Combined fringe and Fabry-Perot laser anemometer for 3 component velocity measurements in turbine stator cascade facility

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.; Goldman, Louis J.

    1986-01-01

    A laser anemometer is described that was developed for use in a 508 mm diameter annular turbine stator cascade facility. All three velocity components are measured through a single restricted optical port, both within the stator vane row and downstream of the vanes. The measurements are made through a cylindrical window in the casing that matches the tip radius of the cascade. The stator tested has a contoured hub endwall that results in a large radial flow near the hub. The anemometer uses a standard fringe configuration (LFA) with a fluorescent aerosol seed to measure the axial and circumferential velocity components. The radial component is measured with a confocal Fabry-Perot interferometer. The two configurations are combined in a single optical system and can operate simultaneously. Data are presented to illustrate the capabilities of the system.

  8. Combined fringe and Fabry-Perot laser anemometer for three component velocity measurements in turbine stator cascade facility

    NASA Technical Reports Server (NTRS)

    Seasholtz, R. G.; Goldman, L. J.

    1986-01-01

    A laser anemometer is described that was developed for use in a 508 mm diameter annular turbine stator cascade facility. All three velocity components are measured through a single restricted optical port, both within the stator vane row and downstream of the vanes. The measurements are made through a cylindrical window in the casing that matches the tip radius of the cascade. The stator tested has a contoured hub endwall that results in a large radial flow near the hub. The anemometer uses a standard fringe configuration (LFA) with a fluorescent aerosol seed to measure the axial and circumferential velocity components. The radial component is measured with a confocal Fabry-Perot interferometer. The two configurations are combined in a single optical system and can operate simultaneously. Data are presented to illustrate the capabilities of the system.

  9. Method for the determination of the three-dimensional aerodynamic field of a rotor-stator combination to compressible flow

    NASA Technical Reports Server (NTRS)

    Ramachandra, Sridhar M.; Bober, Lawrence J.; Khandelwal, Suresh

    1987-01-01

    Using the lifting surface theory and the acceleration potential method for the flow field of an axial turbocompressor stage, a recursive and a direct method are presented that make use of the eigenfunction solutions of the isolated rotor and stator to solve for the rotor-stator interaction problem. The net pressure distribution on the rotor and stator blades is represented by modified Birnbaum series, whose coefficients are determined using a matrix procedure and satisfying the boundary conditions on the surface of the blades. The relation between the matrix operators of the recursive and the direct methods is also shown. Expressions have been given for the blade circulation, the axial and tangential forces on the blade, the rotor power required, and the induced upwash velocity of the stage.

  10. Introduction of a new scaling approach for particle size reduction in toothed rotor-stator wet mills.

    PubMed

    Engstrom, Joshua; Wang, Chenchi; Lai, Chiajen; Sweeney, Jason

    2013-11-18

    A new scaling approach has been demonstrated for particle size reduction of an active pharmaceutical ingredient (API) in toothed rotor-stator wet mills for a wide range of wet milling conditions and scales. Compound A was crystallized by a cooling crystallization protocol in ethanol and wet milled with 2 types of lab scale mills and 1 pilot plant mill. The particle size was analyzed by FBRM (focused beam reflectance measurement), static light scattering and optical microscopy. The correlation between particle size and the energy input calculations, tailored for the toothed rotor-stator wet mill, had R(2)=0.90 on a logarithmic plot. The new scaling approach forms the basis to correlate API particle size to energy input in toothed rotor-stator wet mills by accounting for wet mill tooth configuration and geometry, rotor tip speed and the probabilistic effects of collision such as shear frequency and slurry residence time. PMID:24012859

  11. Electromagnetic and Mechanical design of a Fractional-slot-windings Axial-flux PM synchronous machine with Soft Magnetic Compound Stator

    Microsoft Academic Search

    Fabrizio Marignetti; Giovanni Tomassi; Piergiacomo Cancelliere; Vincenzo Delli Colli; Roberto Di Stefano; Maurizio Scarano

    2006-01-01

    Despite their favorable aspect ratio, axial flux PM synchronous machines can compete with traditional radial flux machines in terms of torque and power density only if the number of pole-pairs is sufficiently high and the ratio axial length\\/outer diameter is low. Since axial flux PM synchronous machines have an inner stator hole, the number of stator slots is bounded, therefore

  12. Preparation of emulsions by rotor-stator homogenizer and ultrasonic cavitation for the cosmeceutical industry.

    PubMed

    Han, Ng Sook; Basri, Mahiran; Abd Rahman, Mohd Basyaruddin; Abd Rahman, Raja Noor Zaliha Raja; Salleh, Abu Bakar; Ismail, Zahariah

    2012-01-01

    Oil-in-water (O/W) nanoemulsions play an important key role in transporting bioactive compounds into a range of cosmeceutical products to the skin. Small droplet sizes have an inherent stability against creaming, sedimentation, flocculation, and coalescence. O/W emulsions varying in manufacturing process were prepared. The preparation and characterization of O/W nanoemulsions with average diameters of as low as 62.99 nm from palm oil esters were carried out. This was achieved using rotor-stator homogenizer and ultrasonic cavitation. Ultrasonic cell was utilized for the emulsification of palm oil esters and water in the presence of mixed surfactants, Tween 80 and Span 80 emulsions with a mean droplet size of 62.99 nm and zeta potential value at -37.8 mV. Results were comparable with emulsions prepared with rotor-stator homogenizer operated at 6000 rpm for 5 min. The stability of the emulsions was evaluated through rheology measurement properties. This included non-Newtonian viscosity, elastic modulus G', and loss modulus G?. A highly stable emulsion was prepared using ultrasonic cavitation comprising a very small particle size with higher zeta potential value and G' > G? demonstrating gel-like behavior. PMID:23089355

  13. Numerical simulation of a closed rotor-stator system using Large Eddy Simulation

    NASA Astrophysics Data System (ADS)

    Amouyal, Solal Abraham Teva

    A large eddy simulation of an enclosed annular rotor stator cavity is presented. The geometry is characterized by a large aspect ratio G = (b-a)/h = 18.32 and a small radius ratio a/b = 0.152, where a and b are the inner and outer radii of the rotating disk and h is the interdisk spacing. The rotation rate o under consideration is equivalent to the rotational Reynolds number Re = o b2 /nu= 9.5x104 , where nu is the kinematic viscosity. The main objective of this study is to correctly simulate the rotor stator cavity using a low order numerical scheme on unstructured grids. The numerical simulations were run on the software AVBP developed by the Centre Europeen de Recherche et de Formation Avancee en Calcul Scientific. The results were compared to the experimental results obtained by Sebastien Poncet of Universit e Aix-Marseille. Two large eddy simulations techniques were used: the Smagorinsky and Wall-adapting local eddy-viscosity models. The simulations were run on three set of grids, each with a different cell resolution-14, 35 and 50- along the thickness of the system. Results from each mesh show a good qualitative agreement of the mean velocity field with Poncet's experimental results. It was found that the Samgorinsky model to be more appropriate for this configuration.

  14. PSP Measurement of Stator Vane Surface Pressures in a High Speed Fan

    NASA Technical Reports Server (NTRS)

    Lepicovsky, Jan

    1998-01-01

    This paper presents measurements of static pressures on the stator vane suction side of a high-speed single stage fan using the technique of pressure sensitive paint (PSP). The paper illustrates development in application of the relatively new experimental technique to the complex environment of internal flows in turbomachines. First, there is a short explanation of the physics of the PSP technique and a discussion of calibration methods for pressure sensitive paint in the turbomachinery environment. A description of the image conversion process follows. The recorded image of the stator vane pressure field is skewed due to the limited optical access and must be converted to the meridional plane projection for comparison with analytical predictions. The experimental results for seven operating conditions along an off-design rotational speed line are shown in a concise form, including performance map points, mindspan static tap pressure distributions, and vane suction side pressure fields. Then, a comparison between static tap and pressure sensitive paint data is discussed. Finally, the paper lists shortcomings of the pressure sensitive paint technology and lessons learned in this high-speed fan application.

  15. On Acoustic Source Specification for Rotor-Stator Interaction Noise Prediction

    NASA Technical Reports Server (NTRS)

    Nark, Douglas M.; Envia, Edmane; Burley, Caesy L.

    2010-01-01

    This paper describes the use of measured source data to assess the effects of acoustic source specification on rotor-stator interaction noise predictions. Specifically, the acoustic propagation and radiation portions of a recently developed coupled computational approach are used to predict tonal rotor-stator interaction noise from a benchmark configuration. In addition to the use of full measured data, randomization of source mode relative phases is also considered for specification of the acoustic source within the computational approach. Comparisons with sideline noise measurements are performed to investigate the effects of various source descriptions on both inlet and exhaust predictions. The inclusion of additional modal source content is shown to have a much greater influence on the inlet results. Reasonable agreement between predicted and measured levels is achieved for the inlet, as well as the exhaust when shear layer effects are taken into account. For the number of trials considered, phase randomized predictions follow statistical distributions similar to those found in previous statistical source investigations. The shape of the predicted directivity pattern relative to measurements also improved with phase randomization, having predicted levels generally within one standard deviation of the measured levels.

  16. Flow visualization for investigating stator losses in a multistage axial compressor

    NASA Astrophysics Data System (ADS)

    Smith, Natalie R.; Key, Nicole L.

    2015-05-01

    The methodology and implementation of a powder-paint-based flow visualization technique along with the illuminated flow physics are presented in detail for application in a three-stage axial compressor. While flow visualization often accompanies detailed studies, the turbomachinery literature lacks a comprehensive study which both utilizes flow visualization to interrupt the flow field and explains the intricacies of execution. Lessons learned for obtaining high-quality images of surface flow patterns are discussed in this study. Fluorescent paint is used to provide clear, high-contrast pictures of the recirculation regions on shrouded vane rows. An edge-finding image processing procedure is implemented to provide a quantitative measure of vane-to-vane variability in flow separation, which is approximately 7 % of the suction surface length for Stator 1. Results include images of vane suction side corner separations from all three stages at three loading conditions. Additionally, streakline patterns obtained experimentally are compared with those calculated from computational models. Flow physics associated with vane clocking and increased rotor tip clearance and their implications to stator loss are also investigated with this flow visualization technique. With increased rotor tip clearance, the vane surface flow patterns show a shift to larger separations and more radial flow at the tip. Finally, the effects of instrumentation on the flow field are highlighted.

  17. Analytically computing the flux linked by a switched reluctance motor phase when the stator and rotor poles overlap

    Microsoft Academic Search

    Arthur Radun

    2000-01-01

    This paper develops an analytical model for the flux linked by a phase of a switched reluctance motor (SRM) starting with the basic laws for magnetic fields. Thus this model is not empirical nor does it require any data from the machine being modeled or any finite-element analysis results. The model is applicable to rotor positions where the stator and

  18. Modeling of stator teeth-tip iron losses in fractional-slot concentrated winding surface PM machines

    Microsoft Academic Search

    P. B. Reddy; T. M. Jahns

    2009-01-01

    This paper presents a model for estimating the iron losses in the stator teeth tips of surface permanent magnet (SPM) machines with fractional-slot concentrated windings based on simplified semi-analytical solutions for the machine flux densities. This model is being developed for use in machine design optimization software that analyzes very large numbers of candidate designs. Tooth tip design details are

  19. Effectiveness of stress grading coatings on form wound stator coil groundwall insulation under fast rise time pulse voltages

    Microsoft Academic Search

    Fermin P. Espino-Cortes; E. A. Cherney; Shesha Jayaram

    2005-01-01

    In this paper, the effectiveness of stress grading coatings (SGCs) on form wound stator coil groundwall insulation under fast rise time pulses is analyzed. The combined performance of the stress grading coating and the semiconductive slot coating is studied under fast rise time transient voltages. During the rapid rise of voltage, the high stress moves from the stress grading coating

  20. Design and control of a single stator dual PM rotors axial synchronous machine for hybrid electric vehicles

    Microsoft Academic Search

    Lucian Nicolae Tutelea; Sorin Ioan Deaconu; Ion Boldea; Fabrizio Marignetti; Gabriel Nicolae Popa

    2011-01-01

    In this paper is presenting the preliminary designing and control of a synchronous machine with axial airgap single stator dual-rotor with permanent surface magnets and different pole pairs number, destined for hybrid electric vehicles (HEV) applications. For machine’s designing was used the equivalent magnetic circuits method that takes into account the saturation and dispersion of the magnetic field. The control

  1. A threaded wobble motor with a 6-pole stator-a micro motor generating large linear displacement

    Microsoft Academic Search

    Tetsuhiko Iizuka; Hiroyuki Fujita

    1996-01-01

    This paper deals with the driving principle and the experimental demonstration of a micro motor which can convert rotation into linear motion and generate large displacement. The motor is a wobble type one; its rotor and stators have screw threads. When the rotor turns, it moves linearly in the axial direction like a screw. The range of linear motion is

  2. F-ATPase: Forced Full Rotation of the Rotor Despite Covalent Cross-link with the Stator*

    E-print Network

    Junge, Wolfgang

    ( A285C 7 P280C). Apparently the high torque of this rotary engine un- coiled the -helix and forced at the rotary compliance of subunit we introduced disulfide bridges between (rotor) and or (stator). We engineered cysteine residues into positions located roughly at the "top," "center," and "bottom" parts

  3. The Torque of Rotary F-ATPase Can Unfold Subunit Gamma If Rotor and Stator Are Cross-Linked

    E-print Network

    Junge, Wolfgang

    cross-linked (via an engineered disulfide bridge) with the bearing, the rotary function of F1 persists an artificial disulfide bridge did not impair the rotary ATPase activity. We newly engineered three mutantsThe Torque of Rotary F-ATPase Can Unfold Subunit Gamma If Rotor and Stator Are Cross-Linked Florian

  4. Reduction of Unbalanced Magnetic Pull (UMP) due to equipotential connections among parallel circuits of the stator winding

    Microsoft Academic Search

    Wilian Oliveira; Mauro Uemori; Johnny Rocha; Renato Carlson

    2009-01-01

    Generator air gap non-uniformity causes an imbalance of magnetic forces that result in unbalanced magnetic pull - UMP. This phenomenon can cause high vibrations on the rotor. The addition of equipotential connections leads to an increment of the circulating current among parallel circuits of the stator winding, decreasing the magnetomotive force of armature reaction. Since the forces of magnetic attraction

  5. Two rotary motors in F-ATP synthase are elastically coupled by a flexible rotor and a stiff stator stalk

    PubMed Central

    Wächter, André; Bi, Yumin; Dunn, Stanley D.; Cain, Brian D.; Sielaff, Hendrik; Wintermann, Frank; Engelbrecht, Siegfried; Junge, Wolfgang

    2011-01-01

    ATP is synthesized by ATP synthase (FOF1-ATPase). Its rotary electromotor (FO) translocates protons (in some organisms sodium cations) and generates torque to drive the rotary chemical generator (F1). Elastic power transmission between FO and F1 is essential for smoothing the cooperation of these stepping motors, thereby increasing their kinetic efficiency. A particularly compliant elastic domain is located on the central rotor (c10–15/?/?), right between the two sites of torque generation and consumption. The hinge on the active lever on subunit ? adds further compliance. It is under contention whether or not the peripheral stalk (and the “stator” as a whole) also serves as elastic buffer. In the enzyme from Escherichia coli, the most extended component of the stalk is the homodimer b2, a right-handed ?-helical coiled coil. By fluctuation analysis we determined the spring constant of the stator in response to twisting and bending, and compared wild-type with b-mutant enzymes. In both deformation modes, the stator was very stiff in the wild type. It was more compliant if b was elongated by 11 amino acid residues. Substitution of three consecutive residues in b by glycine, expected to destabilize its ?-helical structure, further reduced the stiffness against bending deformation. In any case, the stator was at least 10-fold stiffer than the rotor, and the enzyme retained its proton-coupled activity. PMID:21368147

  6. Analysis of a transverse flux machine with E-shaped stator using three dimensional scalar potential finite element method

    Microsoft Academic Search

    Yu Gong; Wenpeng Zheng; Dong Zhang; Jianzhong Jiang

    2009-01-01

    Transverse flux machine (TFM) has flexible and multiple arrangements with different characteristics for its electromagnetic decoupling. This paper presents a novel TFM with E-shaped stator core which combines the advantage of high specific torque with ease of manufacturing. Because of the complexity of TFM flux paths, the software S3DFEM based on scalar potential method is developed to analyze it. The

  7. Performance Improvement of IPMSM Position Sensorless Vector Control System by the Online Identification of Stator Resistance and Permanent Magnet Flux

    Microsoft Academic Search

    Tetsuya Fukumoto; Shigenori Togashi; Yoichi Hayashi

    2009-01-01

    Some of the position sensorless vector control methods of IPMSM use the back electromotive force and require accurate values of motor parameter. Their stability is influenced by motor parameter errors. Particularly, it becomes a problem in the case of extreme temperature variation and operation at low speed. In this paper, the online identification of stator resistance and permanent magnet flux

  8. Experimental comparison between a counter-rotating axial-flow fan and a conventional rotor-stator stage

    E-print Network

    Paris-Sud XI, Université de

    Experimental comparison between a counter-rotating axial-flow fan and a conventional rotor industrial fields. The counter-rotating axial-flow fans could be a promising way to achieve operating at the same point: a single subsonic axial-flow fan, a conventional rotor-stator stage

  9. Study of stator-vane fluctuating pressures in a turbofan engine for static and flight tests

    NASA Technical Reports Server (NTRS)

    Mueller, A. W.

    1984-01-01

    As part of a program to study the fan noise generated from turbofan engines, fluctuating surface pressures induced by fan-rotor wakes were measured on core- and bypass-stator outlet guide vanes of a modified JT15D-1 engine. Tests were conducted with the engine operating on an outdoor test stand and in flight. The amplitudes of pressures measured at fan-rotor blade-passage fundamental frequencies were generally higher and appeared less stable for the static tests than for the flight tests. Fluctuating pressures measured at the blade-passage frequency of the high-speed core compressor were interpreted to be acoustic; however, disturbance trace velocities for either the convected rotor wakes or acoustic pressures were difficult to interpret because of the complex environment.

  10. Transient technique for measuring heat transfer coefficients on stator airfoils in a jet engine environment

    NASA Astrophysics Data System (ADS)

    Gladden, H. J.; Proctor, M. P.

    A transient technique was used to measure heat transfer coefficients on stator airfoils in a high-temperature annular cascade at real engine conditions. The transient response of thin film thermocouples on the airfoil surface to step changes in the gas stream temperature was used to determine these coefficients. In addition, gardon gages and paired thermocouples were also utilized to measure heat flux on the airfoil pressure surface at steady state conditions. The tests were conducted at exit gas stream Reynolds numbers of one-half to 1.9 million based on true chord. The results from the transient technique show good comparison with the steady-state results in both trend and magnitude. In addition, comparison is made with the STAN5 boundary layer code and shows good comparison with the trends. However, the magnitude of the experimental data is consistently higher than the analysis.

  11. A numerical analysis of tonal acoustics in rotor-stator interactions

    NASA Technical Reports Server (NTRS)

    Rangwalla, A. A.; Rai, M. M.

    1993-01-01

    In this study, the unsteady, thin-layer, Navier-Stokes equations are solved using a system of patched grids for a rotor-stator configuration of an axial turbine. The study focuses on the plurality of spinning modes that are present in such an interaction. The propagation of these modes in the upstream and downstream regions is analyzed and compared with numerical results. It was found that the numerically calculated tonal acoustics could be affected by the type of numerical boundary conditions employed at the inlet and exit of the computational boundaries and the grid spacing in the upstream and downstream regions. Results in the form of surface pressure amplitudes and the spectra of turbine tones and their far field behavior are presented. Numerical results and experimental data are compared wherever possible. The 'mode-content' for different harmonics of blade-passage frequency is shown to conform with that predicted by a kinematical analysis.

  12. An explicit Runge-Kutta method for unsteady rotor/stator interaction

    NASA Technical Reports Server (NTRS)

    Jorgenson, Philip C. E.; Chima, Rodrick V.

    1988-01-01

    A quasi-three-dimensional rotor/stator analysis has been developed for blade-to-blade flows in turbomachinery. The analysis solves the unsteady Euler or thin-layer Navier-Stokes equations in a body-fitted coordinate system. It accounts for the effects of rotation, radius change, and stream-surface thickness. The Baldwin-Lomax eddy-viscosity model is used for turbulent flows. The equations are integrated in time using a four-stage Runge-Kutta scheme with a constant timestep. Results are shown for the first stage of the Space Shuttle Main Engine high pressure fuel turbopump. Euler and Navier-Stokes results are compared on the scaled single- and multi-passage machine. The method is relatively fast and the quasi-three-dimensional formulation is applicable to a wide range of turbomachinery geometries.

  13. Crystal structure of yeast V-ATPase subunit C reveals its stator function.

    PubMed

    Drory, Omri; Frolow, Felix; Nelson, Nathan

    2004-12-01

    Vacuolar H(+)-ATPase (V-ATPase) has a crucial role in the vacuolar system of eukaryotic cells. It provides most of the energy required for transport systems that utilize the proton-motive force that is generated by ATP hydrolysis. Some, but not all, of the V-ATPase subunits are homologous to those of F-ATPase and the nonhomologous subunits determine the unique features of V-ATPase. We determined the crystal structure of V-ATPase subunit C (Vma5p), which does not show any homology with F-ATPase subunits, at 1.75 A resolution. The structural features suggest that subunit C functions as a flexible stator that holds together the catalytic and membrane sectors of the enzyme. A second crystal form that was solved at 2.9 A resolution supports the flexible nature of subunit C. These structures provide a framework for exploring the unique mechanistic features of V-ATPases. PMID:15540116

  14. Stator and Rotor Flux Based Deadbeat Direct Torque Control of Induction Machines

    NASA Technical Reports Server (NTRS)

    Kenny, Barbara H.; Lorenz, Robert D.

    2003-01-01

    A new, deadbeat type of direct torque control is proposed, analyzed and experimentally verified in this paper. The control is based on stator and rotor flux as state variables. This choice of state variables allows a graphical representation which is transparent and insightful. The graphical solution shows the effects of realistic considerations such as voltage and current limits. A position and speed sensorless implementation of the control, based on the self-sensing signal injection technique, is also demonstrated experimentally for low speed operation. The paper first develops the new, deadbeat DTC methodology and graphical representation of the new algorithm. It then evaluates feasibility via simulation and experimentally demonstrates performance of the new method with a laboratory prototype including the sensorless methods.

  15. Flow visualization study of the horseshoe vortex in a turbine stator cascade

    NASA Technical Reports Server (NTRS)

    Gaugler, R. E.; Russell, L. M.

    1982-01-01

    Flow visualization techniques were used to show the behavior of the horseshoe vortex in a large scale turbine stator cascade. Oil drops on the end wall surface flowed in response to local shear stresses, indicating the limiting flow streamlines at the surface. Smoke injected into the flow and photographed showed time averaged flow behavior. Neutrally bouyant helium filled soap bubbles followed the flow and showed up on photographs as streaks, indicating the paths followed by individual fluid particles. Preliminary attempts to control the vortex were made by injecting air through control jets drilled in the end wall near the vane leading edge. Seventeen different hole locations were tested, one at a time, and the effect of the control jets on the path follwed by smoke in the boundary layer was recorded photographically.

  16. Component Performance Investigation of J71 Experimental Turbine VII: Effect of First-stator Adjustment; Over-all Performance of J71-97 Turbine with 87-percent-design Stator Area

    NASA Technical Reports Server (NTRS)

    Schum, Harold J; Petrash, Donald A; Davison, Elmer H

    1957-01-01

    The performance results, as well as a compressor-turbine match point study based on a particular mode of engine operation, are compared with those previously obtained with the same turbine having first-stator areas 70, 95.6, and 132 percent of design. Maximum efficiencies for all turbine configurations were high, on the order of 87 to 89 percent. The efficiencies obtained at the match points for the 87-, 95.6-, and 132-percent turbines were slightly lower. No match point for the 70-percent turbine was obtained because, with first-stator areas less than 75.5 percent of design, the turbine would develop insufficient work to drive the compressor at the match point.

  17. Identification and control of induction motor stator currents using fast on-line random training of a neural network

    Microsoft Academic Search

    Bruce Burton; Farrukh Kamran; Ronald G. Harley; Thomas G. Habetler; Martin A. Brooke; Ravi Poddar

    1997-01-01

    Artificial neural networks (ANNs), which have no off-line pretraining, can be trained continually on-line to identify an inverter-fed induction motor and control its stator currents. Due to the small time constants of the motor circuits, the time to complete one training cycle has to be extremely small. This paper proposes and evaluates a new form of the random weight change

  18. Progress on IEC 60034-18-42 for Qualification of Stator Insulation for Medium-Voltage Inverter Duty Applications

    Microsoft Academic Search

    M. K. W. Stranges; G. C. Stone; D. L. Bogh

    2007-01-01

    There is an industry need for suitable methods to qualify medium-and high-voltage stator insulation systems for inverter duty applications. Technical Specification (TS) IEC 60034-18-42 is being written to address the unique requirements of form-wound micaceous systems to withstand inverter pulses, characterized by elevated voltage, fast rise times, and high frequency impulse repetition rates. These machines do not operate under the

  19. A sensorless stator flux oriented vector controlled induction motor drive with neuro-fuzzy based performance enhancement

    Microsoft Academic Search

    Bimal K. Bose; Nitin R. Patel

    1997-01-01

    A high-performance stator flux oriented speed sensorless direct vector-controlled induction motor drive is described in the paper. The drive can start from stand-still, operate at any speed in all the quadrants including the field-weakening region, and then stop at zero speed. The drive incorporated the following novel features: (1) software-programmable cascaded low-pass filter units permit machine terminal voltage integration to

  20. Design and Analyses of a Coreless-Stator-Type Bearingless Motor\\/Generator for Clean Energy Generation and Storage Systems

    Microsoft Academic Search

    M. Ooshima; S. Kitazawa; A. Chiba; T. Fukao; D. G. Dorrell

    2006-01-01

    This paper presents a design for a new bearingless motor\\/generator suitable for use in clean energy generation and storage systems. The machine is an outer-rotor type with a coreless stator. By using this type of bearingless drive in an energy generation or storage system, it is possible to obtain high efficiency, maintenance-free operation, and a long life cycle. In this

  1. Influence of parameters on performance of permanent magnet brushless DC motor with the air-cored stator

    Microsoft Academic Search

    Huijun Wang; Guangxu Zhou; Zhaoyan Xie; Sensen Song

    2010-01-01

    The airgap magnetic field distribution and back-emf waveform are analyzed from the 3-D finite element models of the permanent magnet brushless DC (BLDC) motor with air-cored stator. The influence of magnet thickness, length of airgap and outer diameter of the rotor on the performance is investigated. It can be found that waveform of back-emf can be improved to reach flat

  2. Cyclic di-GMP-mediated repression of swarming motility by Pseudomonas aeruginosa PA14 requires the MotAB stator.

    PubMed

    Kuchma, S L; Delalez, N J; Filkins, L M; Snavely, E A; Armitage, J P; O'Toole, G A

    2015-02-01

    The second messenger cyclic diguanylate (c-di-GMP) plays a critical role in the regulation of motility. In Pseudomonas aeruginosa PA14, c-di-GMP inversely controls biofilm formation and surface swarming motility, with high levels of this dinucleotide signal stimulating biofilm formation and repressing swarming. P. aeruginosa encodes two stator complexes, MotAB and MotCD, that participate in the function of its single polar flagellum. Here we show that the repression of swarming motility requires a functional MotAB stator complex. Mutating the motAB genes restores swarming motility to a strain with artificially elevated levels of c-di-GMP as well as stimulates swarming in the wild-type strain, while overexpression of MotA from a plasmid represses swarming motility. Using point mutations in MotA and the FliG rotor protein of the motor supports the conclusion that MotA-FliG interactions are critical for c-di-GMP-mediated swarming inhibition. Finally, we show that high c-di-GMP levels affect the localization of a green fluorescent protein (GFP)-MotD fusion, indicating a mechanism whereby this second messenger has an impact on MotCD function. We propose that when c-di-GMP level is high, the MotAB stator can displace MotCD from the motor, thereby affecting motor function. Our data suggest a newly identified means of c-di-GMP-mediated control of surface motility, perhaps conserved among Pseudomonas, Xanthomonas, and other organisms that encode two stator systems. PMID:25349157

  3. Effective simulation of stability of 3\\/12-phase synchronous generators with simultaneous ac and dc stator connections using MATLAB

    Microsoft Academic Search

    Wang Shanming; Zhang Anming; Wang Xiangheng; Su Pengsheng

    2008-01-01

    Synchronous generators connected with diode-bridge rectifier are used to supply DC power in a wide variety of applications. Serious low-frequency current oscillations may occur in a rectifier-loaded synchronous generator with improper parameters. This paper studies the simulation of stability of the 3\\/12-phase synchronous generator with simultaneous AC and DC stator connections using MATLAB. The abc model of synchronous generators is

  4. Mixed eccentricity diagnosis in Inverter-Fed Induction Motors via the Adaptive Slope Transform of transient stator currents

    NASA Astrophysics Data System (ADS)

    Pons-Llinares, J.; Antonino-Daviu, J.; Roger-Folch, J.; Moríñigo-Sotelo, D.; Duque-Pérez, O.

    2014-10-01

    This paper researches the detection of mixed eccentricity in Inverter-Fed Induction Motors. The classic FFT method cannot be applied when the stator current captured is not in steady state, which is very common in these motors. Therefore, a transform able to detect the time-frequency evolutions of the components present in the transient signal captured must be applied. In order to optimize the result, a method to calculate the theoretical time-frequency evolution of the stator current components is presented, using only the captured current. This previously obtained information enables the use of the proposed transform: the Adaptive Slope Transform, based on appropriately choosing the atom slope in each point analyzed. Thanks to its adaptive characteristics, the time-frequency evolution of the main components in a stator transient current is traced precisely and with high detail in the 2D time-frequency plot obtained. As a consequence, the time-frequency plane characteristic patterns produced by the Eccentricity Related Harmonics are easily and clearly identified enabling a reliable diagnosis. Moreover, the problem of quantifying the presence of the fault is solved presenting a simple and easy to apply method. The transform capabilities have been shown successfully diagnosing an Inverter-Fed Induction Motor with mixed eccentricity during a startup, a decrease in the assigned frequency, and a load variation with and without slip compensation.

  5. Electromagnetic Radial Forces in a Hybrid Eight-Stator-Pole, Six-Rotor-Pole Bearingless Switched-Reluctance Motor

    NASA Technical Reports Server (NTRS)

    Morrison, Carlos R.; Siebert, Mark W.; Ho, Eric J.

    2007-01-01

    Analysis and experimental measurement of the electromagnet force loads on the hybrid rotor in a novel bearingless switched-reluctance motor (BSRM) have been performed. A BSRM has the combined characteristics of a switched-reluctance motor and a magnetic bearing. The BSRM has an eight-pole stator and a six-pole hybrid rotor, which is composed of circular and scalloped lamination segments. The hybrid rotor is levitated using only one set of stator poles. A second set of stator poles imparts torque to the scalloped portion of the rotor, which is driven in a traditional switched reluctance manner by a processor. Analysis was done for nonrotating rotor poles that were oriented to achieve maximum and minimum radial force loads on the rotor. The objective is to assess whether simple one-dimensional magnetic circuit analysis is sufficient for preliminary evaluation of this machine, which may exhibit strong three-dimensional electromagnetic field behavior. Two magnetic circuit geometries, approximating the complex topology of the magnetic fields in and around the hybrid rotor, were employed in formulating the electromagnetic radial force equations. Reasonable agreement between the experimental results and the theoretical predictions was obtained with typical magnetic bearing derating factors applied to the predictions.

  6. Feasibility of using PZT actuators to study the dynamic behavior of a rotating disk due to rotor-stator interaction.

    PubMed

    Presas, Alexandre; Egusquiza, Eduard; Valero, Carme; Valentin, David; Seidel, Ulrich

    2014-01-01

    In this paper, PZT actuators are used to study the dynamic behavior of a rotating disk structure due to rotor-stator interaction excitation. The disk is studied with two different surrounding fluids-air and water. The study has been performed analytically and validated experimentally. For the theoretical analysis, the natural frequencies and the associated mode shapes of the rotating disk in air and water are obtained with the Kirchhoff-Love thin plate theory coupled with the interaction with the surrounding fluid. A model for the Rotor Stator Interaction that occurs in many rotating disk-like parts of turbomachinery such as compressors, hydraulic runners or alternators is presented. The dynamic behavior of the rotating disk due to this excitation is deduced. For the experimental analysis a test rig has been developed. It consists of a stainless steel disk (r = 198 mm and h = 8 mm) connected to a variable speed motor. Excitation and response are measured from the rotating system. For the rotating excitation four piezoelectric patches have been used. Calibrating the piezoelectric patches in amplitude and phase, different rotating excitation patterns are applied on the rotating disk in air and in water. Results show the feasibility of using PZT to control the response of the disk due to a rotor-stator interaction. PMID:25004151

  7. Direct Torque Control with Full Order Stator Flux Observer for Dual-Three Phase Induction Motor Drives

    NASA Astrophysics Data System (ADS)

    Farina, Francesco; Bojoi, Radu; Tenconi, Alberto; Profumo, Francesco

    A Direct Torque Control (DTC) strategy for dual-three phase induction motor drives is discussed in this paper. The induction machine has two sets of stator three-phase windings spatially shifted by 30 electrical degrees with isolated neutral points. The proposed control strategy is based on Proportional Integral (PI) regulators implemented in the stator flux synchronous reference frame. To improve the flux estimation, an Adaptive Stator Flux Observer (ASFO) has been used. Doing so, besides a better flux estimation in contrast to open-loop flux estimators, it is possible to use the observed currents to compensate the inverter non-linear behavior (such as dead-time effects), improving the drive performance at low speed. This is particularly important for low voltage/high current applications, as the drive considered in this paper. The advantages of the discussed control strategy are: constant inverter switching frequency, good transient and steady-state performance and less distorted machine currents in contrast to DTC schemes with variable switching frequency. Experimental results are presented for a 10kW dual three-phase induction motor drive prototype.

  8. Periodic transition on an axial compressor stator: Incidence and clocking effects. Part 2: Transition onset predictions

    SciTech Connect

    Solomon, W.J. [General Electric Aircraft Engines, Cincinnati, OH (United States); Walker, G.J.; Hughes, J.D. [Univ. of Tasmania, Hobart (Australia). School of Engineering

    1999-07-01

    Transition onset observations from a 1.5-stage axial compressor outlet stator presented in Part 1 of this paper are compared with the predictions of conventional transition correlations applied in a quasi-steady manner. The viscous/inviscid interaction code MISES is used to predict the blade surface pressure distributions, and boundary layer development. The temporal variation in transition onset is then predicted using ensemble-averaged free-stream turbulence data from the compressor measurements. This simple procedure captures most significant features of the complex transition process on the compressor, and is clearly superior to fixed transition models based on long-term average free-stream turbulence levels. Parallel computations for both natural and bypass transition modes indicate that the natural transition mode tends to dominate on the compressor. This is at variance with turbine airfoil experience, where bypass transition is clearly more important. Comparison of prediction and experiment highlights the significance of leading edge potential flow interactions in promoting periodic wake-induced transition. Viscous/inviscid interactions in the neighborhood of transition can also have an important influence on boundary layer stability and separation phenomena.

  9. Detached eddy simulation of the rotor-stator interaction phenomenon in a moving cascade of airfoils

    NASA Astrophysics Data System (ADS)

    Guardo, A.; Fontanals, A.; Coussirat, M.; Egusquiza, E.

    2012-11-01

    Flow inside turbomachinery is fairly complex in general, due to the geometry complexity and the intrinsic structure of the flow. Rotor-Stator Interaction (RSI) has a strong influence on the machine behavior, especially when the machine is operating in off-design conditions, where flow complexity increases due to the presence of boundary layer detachment influencing the general flow pattern and creating pressure pulses that can enhance the RSI behavior. These interactions can have a significant impact on the vibrational and acoustical characteristics of the machine. For gaining insight in the RSI characteristics and the behavior of a turbomachinery under this kind of flow interaction, in this work the RSI generated between a moving cascade of airfoils and fixed flat plate located downstream was studied by means of Computational Fluid Dynamics (CFD) using Detached Eddy Simulation (DES). The upstream boundary layer influence on the wake of the moving cascade, and the subsequent wake-boundary layer interaction between the cascade and a fixed flat plate downstream were obtained and compared against experimental and previous numerical results (obtained with Eddy Viscosity Models). Design and off-design conditions were modeled and a detailed comparison between them has been made. To analyze in detail the flow pattern, mean and fluctuating velocities were obtained and compared against experimental results. Furthermore, results concerning to turbulence intensity were compared against an experimental database.

  10. Detection of stator winding faults in induction motors using three-phase current monitoring.

    PubMed

    Sharifi, Rasool; Ebrahimi, Mohammad

    2011-01-01

    The objective of this paper is to propose a new method for the detection of inter-turn short circuits in the stator windings of induction motors. In the previous reported methods, the supply voltage unbalance was the major difficulty, and this was solved mostly based on the sequence component impedance or current which are difficult to implement. Some other methods essentially are included in the offline methods. The proposed method is based on the motor current signature analysis and utilizes three phase current spectra to overcome the mentioned problem. Simulation results indicate that under healthy conditions, the rotor slot harmonics have the same magnitude in three phase currents, while under even 1 turn (0.3%) short circuit condition they differ from each other. Although the magnitude of these harmonics depends on the level of unbalanced voltage, they have the same magnitude in three phases in these conditions. Experiments performed under various load, fault, and supply voltage conditions validate the simulation results and demonstrate the effectiveness of the proposed technique. It is shown that the detection of resistive slight short circuits, without sensitivity to supply voltage unbalance is possible. PMID:21074767

  11. Component Performance Investigation of J71 Experimental Turbine. Iv-effect of First-stator Adjustment; Over-all Performance of J71-97 Turbine with 132-percent-design Stator Area

    NASA Technical Reports Server (NTRS)

    Davison, Elmer H; Petrash, Donald A; Schum, Harold J

    1956-01-01

    An experimental invesitgation of the effect of increasing the first-stator area of the J71-97 experimental three-stage turbine from 97 percent of design to 132 percent revealed (1) the maximum efficiency obtained decreased from 0.891 to 0.869, (2) the choking equivalent weight flows increased by approximately 13.6 percent, and (3) at the turbine match points required to maintain the compressor at constant design equivalent conditions the turbine efficiency decreased from 0.87 to 0.86.

  12. Measurements of the unsteady flow field within the stator row of a transonic axial-flow fan. Part 2: Results and discussion

    NASA Technical Reports Server (NTRS)

    Hathaway, M. D.; Suder, K. L.; Okiishi, T. H.; Strazisar, A. J.; Adamczyk, J. J.

    1987-01-01

    Unsteady velocity field measurements made within the stator row of a transonic axial-flow fan are presented. Measurements were obtained at midspan for two different stator blade rows using a laser anemometer. The first stator row consists of double circular-arc airfoils with a solidity of 1.68. The second features controlled-diffusion airfoils with a solidity of 0.85. Both were tested at design-speed peak efficiency conditions. In addition, the controlled-diffusion stator was also tested at near stall conditions. The procedures developed here are used to identify the rotor wake generated and unresolved unsteadiness from the velocity measurements (rotor wake generated unsteadiness refers to the unsteadiness generated by the rotor wake velocity deficit and unresolved unsteadiness refers to all remaining unsteadiness which contributes to the spread in the distribution of velocities such as vortex shedding, turbulence, etc.). Auto and cross correlations of these unsteady velocity fluctuations are presented to show their relative magnitude and spatial distributions. Amplification and attenuation of both rotor wake generated and unresolved unsteadiness are shown to occur within the stator blade passage.

  13. Measurements of the unsteady flow field within the stator row of a transonic axial-flow fan. II - Results and discussion

    NASA Technical Reports Server (NTRS)

    Hathaway, M. D.; Suder, K. L.; Strazisar, A. J.; Adamczyk, J. J.; Okiishi, T. H.

    1987-01-01

    Unsteady velocity field measurements made within the stator row of a transonic axial-flow fan are presented. Measurements were obtained at midspan for two different stator blade rows using a laser anemometer. The first stator row consists of double circular-arc airfoils with a solidity of 1.68. The second features controlled-diffusion airfoils with a solidity of 0.85. Both were tested at design-speed peak efficiency conditions. In addition, the controlled-diffusion stator was also tested at near stall conditions. The procedures developed here are used to identify the rotor wake generated and unresolved unsteadiness from the velocity measurements (rotor wake generated unsteadiness refers to the unsteadiness generated by the rotor wake velocity deficit and unresolved unsteadiness refers to all remaining unsteadiness which contributes to the spread in the distribution of velocities such as vortex shedding, turbulence, etc.). Auto and cross correlations of these unsteady velocity fluctuations are presented to show their relative magnitude and spatial distributions. Amplification and attenuation of both rotor wake generated and unresolved unsteadiness are shown to occur within the stator blade passage.

  14. The physical phenomena associated with stator winding insulation condition as detected by the ramped direct high-voltage method

    NASA Astrophysics Data System (ADS)

    Rux, Lorelynn Mary

    Deregulation of the electric utility industry has increased the need to monitor the state of powerplant equipment, such as critical generators and motors, to improve availability and reduce life cycle costs via condition-based maintenance. To achieve these goals, nondestructive condition assessment and diagnostic tests are necessary to evaluate the quality and condition of a machine's stator winding insulation system. Periodic tests are generally conducted to monitor insulation aging, diagnose problems, or provide some assurance that the winding has a minimum level of electrical strength. The basic principles of insulation testing are presented herein, and the physical mechanisms that affect the current versus voltage response are described. A stator winding insulation model was developed based on this theoretical foundation for use in understanding and analyzing the macroscopic behavior of complex insulation phenomena. A comprehensive, controlled laboratory experiment was conducted on a set of stator coils that were deliberately manufactured with and without insulation defects. Specific defects were chosen to represent the types of insulation problems typically encountered during manufacture or as a result of in-service aging, and included lack of resin cure, loosely-applied insulating tapes, internal conductive contamination, reduced density of the groundwall insulation, and thermal cycling damage. Results are presented from a series of electrical tests conducted on the coil specimens to compare the effectiveness of various test methods in detecting the different insulation problems. The tests included insulation resistance, polarization index, ramped direct voltage, dissipation factor, dielectric spectroscopy, partial discharge, and recovery voltage measurements. Dielectric principles and testing experience obtained during this investigation were applied to a collection of test results obtained by the author from in-service machines during the past ten years. These results and analyses provide a practical illustration of the ability of the ramped direct high-voltage test method to distinguish between normal insulation and that with problems, and to help identify the cause and extent of the deficiencies. While no single diagnostic method is ideally suited to detect all possible stator winding insulation problems, ramped voltage tests are shown to be useful in determining when corrective actions are needed and what the appropriate actions are.

  15. Impact of clocking on the aero-thermodynamics of a second stator tested in a one and a half stage HP turbine

    NASA Astrophysics Data System (ADS)

    Billiard, N.; Paniagua, Guillermo; Dénos, R.

    2008-06-01

    This paper focuses on the experimental investigation of the time-averaged and time-accurate aero-thermodynamics of a second stator tested in a 1.5 stage high-pressure turbine. The effect of clocking on aerodynamic and heat transfer are investigated. Tests are performed under engine representative conditions in the VKI compression tube CT3. The test program includes four different clocking positions, i.e. relative pitch-wise positions between the first and the second stator. Probes located upstream and downstream of the second stator provide the thermodynamic conditions of the flow field. On the second stator airfoil, measurements are taken around the blade profile at 15, 50 and 85% span with pressure sensors and thin-film gauges. Both time-averaged and time-resolved aspects of the flow field are addressed. Regarding the time-averaged results, clocking effects are mainly observed within the leading edge region of the second stator, the largest effects being observed at 15% span. The surface static pressure distribution is changed locally, hence affecting the overall airfoil performance. For one clocking position, the thermal load of the airfoil is noticeably reduced. Pressure fluctuations are attributed to the passage of the upstream transonic rotor and its associated pressure gradients. The pattern of these fluctuations changes noticeably as a function of clocking. The time-resolved variations of heat flux and static pressure are analyzed together showing that the major effect is due to a potential interaction. The time-resolved pressure distribution integrated along the second stator surface yields the unsteady forces on the vane. The magnitude of the unsteady force is very dependent on the clocking position.

  16. Transportation of a 451 ton generator stator and a 234 ton generator rotor from Hartsville, TN, to Los Alamos, NM

    SciTech Connect

    Boenig, H.J.; Rogers, J.D.; McLelland, G.R.; Pelts, C.T. (Los Alamos National Lab., NM (USA); McLelland Engineering, Dallas, TX (USA); Reliance Crane and Rigging, Inc., Phoenix, AZ (USA))

    1989-01-01

    A 1430 MVA steam turbine generator was acquired from a cancelled nuclear power plant in Tennessee to be used as the pulsed power and energy storage unit for the Confinement Physics Research Facility being built at Los Alamos, NM. The transportation from Hartsville, near Nashville, TN, to Los Alamos, NM, of the two largest single pieces of the generator, a 451 t stator and a 234 t rotor presented a special challenge. Details of the move, by barge from Hartsville to Catoosa, near Tulsa, OK, by rail from Catoosa to Lamy, near Santa Fe, NM, and by road from Lamy to Los Alamos are described. The greatest difficulty of the successful move was the crossing of the Rio Grande river on an existing reinforced concrete bridge. The two-lane wide road transporters for the stator and rotor were fitted with outriggers to provide a four-lane wide vehicle, thus spreading the load over the entire bridge width and meeting acceptable load distribution and bridge safety factors. 2 refs., 6 figs.

  17. Broadband Noise of Fans - With Unsteady Coupling Theory to Account for Rotor and Stator Reflection/Transmission Effects

    NASA Technical Reports Server (NTRS)

    Hanson, Donald B.

    2001-01-01

    This report examines the effects on broadband noise generation of unsteady coupling between a rotor and stator in the fan stage of a turbofan engine. Whereas previous acoustic analyses treated the blade rows as isolated cascades, the present work accounts for reflection and transmission effects at both blade rows by tracking the mode and frequency scattering of pressure and vortical waves. The fan stage is modeled in rectilinear geometry to take advantage of a previously existing unsteady cascade theory for 3D perturbation waves and thereby use a realistic 3D turbulence spectrum. In the analysis, it was found that the set of participating modes divides itself naturally into "independent mode subsets" that couple only among themselves and not to the other such subsets. This principle is the basis for the analysis and considerably reduces computational effort. It also provides a simple, accurate scheme for modal averaging for further efficiency. Computed results for a coupled fan stage are compared with calculations for isolated blade rows. It is found that coupling increases downstream noise by 2 to 4 dB. Upstream noise is lower for isolated cascades and is further reduced by including coupling effects. In comparison with test data, the increase in the upstream/downstream differential indicates that broadband noise from turbulent inflow at the stator dominates downstream noise but is not a significant contributor to upstream noise.

  18. Reliability and Confidence Interval Analysis of a CMC Turbine Stator Vane

    NASA Technical Reports Server (NTRS)

    Murthy, Pappu L. N.; Gyekenyesi, John P.; Mital, Subodh K.

    2008-01-01

    High temperature ceramic matrix composites (CMC) are being explored as viable candidate materials for hot section gas turbine components. These advanced composites can potentially lead to reduced weight, enable higher operating temperatures requiring less cooling and thus leading to increased engine efficiencies. However, these materials are brittle and show degradation with time at high operating temperatures due to creep as well as cyclic mechanical and thermal loads. In addition, these materials are heterogeneous in their make-up and various factors affect their properties in a specific design environment. Most of these advanced composites involve two- and three-dimensional fiber architectures and require a complex multi-step high temperature processing. Since there are uncertainties associated with each of these in addition to the variability in the constituent material properties, the observed behavior of composite materials exhibits scatter. Traditional material failure analyses employing a deterministic approach, where failure is assumed to occur when some allowable stress level or equivalent stress is exceeded, are not adequate for brittle material component design. Such phenomenological failure theories are reasonably successful when applied to ductile materials such as metals. Analysis of failure in structural components is governed by the observed scatter in strength, stiffness and loading conditions. In such situations, statistical design approaches must be used. Accounting for these phenomena requires a change in philosophy on the design engineer s part that leads to a reduced focus on the use of safety factors in favor of reliability analyses. The reliability approach demands that the design engineer must tolerate a finite risk of unacceptable performance. This risk of unacceptable performance is identified as a component's probability of failure (or alternatively, component reliability). The primary concern of the engineer is minimizing this risk in an economical manner. The methods to accurately determine the service life of an engine component with associated variability have become increasingly difficult. This results, in part, from the complex missions which are now routinely considered during the design process. These missions include large variations of multi-axial stresses and temperatures experienced by critical engine parts. There is a need for a convenient design tool that can accommodate various loading conditions induced by engine operating environments, and material data with their associated uncertainties to estimate the minimum predicted life of a structural component. A probabilistic composite micromechanics technique in combination with woven composite micromechanics, structural analysis and Fast Probability Integration (FPI) techniques has been used to evaluate the maximum stress and its probabilistic distribution in a CMC turbine stator vane. Furthermore, input variables causing scatter are identified and ranked based upon their sensitivity magnitude. Since the measured data for the ceramic matrix composite properties is very limited, obtaining a probabilistic distribution with their corresponding parameters is difficult. In case of limited data, confidence bounds are essential to quantify the uncertainty associated with the distribution. Usually 90 and 95% confidence intervals are computed for material properties. Failure properties are then computed with the confidence bounds. Best estimates and the confidence bounds on the best estimate of the cumulative probability function for R-S (strength - stress) are plotted. The methodologies and the results from these analyses will be discussed in the presentation.

  19. Turbine blade platform film cooling with simulated stator-rotor purge flow with varied seal width and upstream wake with vortex 

    E-print Network

    Blake, Sarah Anne

    2009-05-15

    The turbine blade platform can be protected from hot mainstream gases by injecting cooler air through the gap between stator and rotor. The effectiveness of this film cooling method depends on the geometry of the slot, the quantity of injected air...

  20. Liquid damping of the stator vibrations at the true mass flow meter 50, a mass flow measuring instrument for non-steady-state two-phase flow

    Microsoft Academic Search

    K. Hain; F. Bruederle; W. Butzer; F. Schloss; T. Vollmer

    1980-01-01

    The liquid damping system used in the TMFM 50 True Mass Flowmeter for damping the stator vibrations excited by the two-phase mixture is reviewed from performance and theoretical points of view. The results furnished by a computer code elaborated for parameter studies are compared with that obtained in a series of vibrations tests on original components. The TMFM 50, nominal

  1. Unsteady Flows in a Single-Stage Transonic Axial-Flow Fan Stator Row. Ph.D. Thesis - Iowa State Univ.

    NASA Technical Reports Server (NTRS)

    Hathaway, Michael D.

    1986-01-01

    Measurements of the unsteady velocity field within the stator row of a transonic axial-flow fan were acquired using a laser anemometer. Measurements were obtained on axisymmetric surfaces located at 10 and 50 percent span from the shroud, with the fan operating at maximum efficiency at design speed. The ensemble-average and variance of the measured velocities are used to identify rotor-wake-generated (deterministic) unsteadiness and turbulence, respectively. Correlations of both deterministic and turbulent velocity fluctuations provide information on the characteristics of unsteady interactions within the stator row. These correlations are derived from the Navier-Stokes equation in a manner similar to deriving the Reynolds stress terms, whereby various averaging operators are used to average the aperiodic, deterministic, and turbulent velocity fluctuations which are known to be present in multistage turbomachines. The correlations of deterministic and turbulent velocity fluctuations throughout the axial fan stator row are presented. In particular, amplification and attenuation of both types of unsteadiness are shown to occur within the stator blade passage.

  2. The effects of inlet turbulence and rotor\\/stator interactions on the aerodynamics and heat transfer of a large-scale rotating turbine model, volume 1

    Microsoft Academic Search

    R. P. Dring; M. F. Blair; H. D. Joslyn; G. D. Power; J. M. Verdon

    1987-01-01

    A combined experimental and analytical program was conducted to examine the effects of inlet turbulence on airfoil heat transfer. Heat transfer measurements were obtained using low conductivity airfoils with miniature thermocouples welded to a thin, electrically heated surface skin. Heat transfer data were acquired for various combinations of low or high inlet turbulence intensity, flow coefficient (incidence), first-stator\\/rotor axial spacing,

  3. On the Stator of Rotary ATP Synthase: The Binding Strength of Subunit to (R )3 As Determined by Fluorescence Correlation Spectroscopy

    E-print Network

    Junge, Wolfgang

    On the Stator of Rotary ATP Synthase: The Binding Strength of Subunit to (R )3 As Determined; ReVised Manuscript ReceiVed July 20, 1999 ABSTRACT: ATP synthase is conceived as a rotary enzyme2c12. ATP synthase is conceived as a molecular engine (3-5). The hydrolysis of ATP drives

  4. Influence of blade passing on the stator wake in a transonic turbine stage investigated by particle image velocimetry and laser vibrometry

    Microsoft Academic Search

    Jakob Woisetschläger; Hermann Lang; Bernd Hampel; Emil Göttlich; Franz Heitmeir

    2003-01-01

    The aerodynamic behaviour of stator and rotor interaction in axial flow turbines is complex and highly unsteady. Particle Image Velocimetry (PIV) and Laser Vibrometry (LV) were used to investigate the phenomena observed in a transonic turbine stage operated continuously in a cold flow test rig. While LV gave basic information on the frequency behaviour of the density fluctuations in the

  5. A novel, single stator dual PM rotor, synchronous machine: Topology, circuit model, controlled dynamics simulation and 3D FEM analysis of torque production

    Microsoft Academic Search

    Ion Boldea; Marcel Topor; Fabrizio Marignetti; Sorin Ioan Deaconu; Lucian Nicolae Tutelea

    2010-01-01

    This paper introduces a novel brushless, single winding and single stator, dual PM rotor axial-air-gap machine capable to deliver independently torque at the two rotors by adequate vector control. The proposed topologies, the circuit model, controlled dynamics simulation and preliminary 3D FEM torque production on a case study constitute the core of the paper. The proposed dual mechanical port system

  6. F-ATPase: forced full rotation of the rotor despite covalent cross-link with the stator.

    PubMed

    Gumbiowski, K; Cherepanov, D; Muller, M; Panke, O; Promto, P; Winkler, S; Junge, W; Engelbrecht, S

    2001-11-01

    In ATP synthase (F(O)F(1)-ATPase) ion flow through the membrane-intrinsic portion, F(O), drives the central "rotor", subunits c(10)epsilongamma, relative to the "stator" ab(2)delta(alphabeta)(3). This converts ADP and P(i) into ATP. Vice versa, ATP hydrolysis drives the rotation backwards. Covalent cross-links between rotor and stator subunits have been shown to inhibit these activities. Aiming at the rotary compliance of subunit gamma we introduced disulfide bridges between gamma (rotor) and alpha or beta (stator). We engineered cysteine residues into positions located roughly at the "top," "center," and "bottom" parts of the coiled-coil portion of gamma and suitable residues on alpha or beta. This part of gamma is located at the center of the (alphabeta)(3) domain with its C-terminal part at the top of F(1) and the bottom part close to the F(O) complex. Disulfide bridge formation under oxidizing conditions was quantitative as shown by SDS-polyacrylamide gel electrophoresis and immunoblotting. As expected both the ATPase activities and the yield of rotating subunits gamma dropped to zero when the cross-link was formed at the center (gammaL262C <--> alphaA334C) and bottom (gammaCys(87) <--> betaD380C) positions. But much to our surprise disulfide bridging impaired neither ATP hydrolysis activity nor the full rotation of gamma and the enzyme-generated torque of oxidized F(1), which had been engineered at the top position (gammaA285C <--> alphaP280C). Apparently the high torque of this rotary engine uncoiled the alpha-helix and forced amino acids at the C-terminal portion of gamma into full rotation around their dihedral (Ramachandran) angles. This conclusion was supported by molecular dynamics simulations: If gammaCys(285)-Val(286) are attached covalently to (alphabeta)(3) and gammaAla(1)-Ser(281) is forced to rotate, gammaGly(282)-Ala(284) can serve as cardan shaft. PMID:11533065

  7. Design and testing of swept and leaned outlet guide vanes to reduce stator-strut-splitter aerodynamic flow interactions

    SciTech Connect

    Wadia, A.R.; Szucs, P.N. [GE Aircraft Engines, Cincinnati, OH (United States); Gundy-Burlet, K.L. [NASA Ames Research Center, Moffet Field, CA (United States)

    1999-07-01

    Large circumferentially varying pressure levels produced by aerodynamic flow interactions between downstream stators and struts present a potential noise and stability margin liability in a compression component. These interactions are presently controlled by tailoring the camber and/or stagger angles of vanes neighboring the fan frame struts. This paper reports on the design and testing of a unique set of swept and leaned fan outlet guide vanes (OGVs) that do not require this local tailoring even though the OGVs are closely coupled with the fan frame struts and splitter to reduce engine length. The swept and leaned OGVs not only reduce core-duct diffusion, but they also reduce the potential flow interaction between the stator and the strut relative to that produced by conventional radial OGVs. First, the design of the outlet guide vanes using a single blade row three-dimensional viscous flow analysis is outlined. Next, a two-dimensional potential flow analysis was used for the coupled OGV-frame system to obtain a circumferentially nonuniform stator stagger angle distribution to reduce the upstream static pressure disturbance further. Recognizing the limitations of the two-dimensional potential flow analysis for this highly three-dimensional set of leaned OGVs, as a final evaluation of the OGV-strut system design, a full three-dimensional viscous analysis of a periodic circumferential sector of the OGVs, including the fan frame struts and splitter, was performed. The computer model was derived from a NASA-developed code used in simulating the flow field for external aerodynamic applications with complex geometries. The tree-dimensional coupled OGV-frame analysis included the uniformly staggered OGV configuration and the variably staggered OGV configuration determined by the two-dimensional potential flow analysis. Contrary to the two-dimensional calculations, the tree-dimensional analysis revealed significant flow problems with the variable staggered OGV configuration and showed less upstream flow nonuniformity with the uniformly staggered OGV configuration. The flow redistribution in both the radial and tangential directions, captured fully only in the three-dimensional analysis, was identified as the prime contributor to the lower flow nonuniformity with the uniformly staggered OGV configuration. The coupled three-dimensional analysis was also used to validate the design at off-design conditions. Engine test performance and stability measurements with both uniformly and variably staggered OGV configurations with and without the presence of inlet distortion confirmed the conclusions from the three-dimensional analysis.

  8. Performance improvements of a subsonic axial-flow compressor by means of a non-axisymmetric stator hub end-wall

    NASA Astrophysics Data System (ADS)

    Zhang, Xuefeng; Lu, Xingen; Zhu, Junqiang

    2013-12-01

    This paper deals with the application of a non-axisymmetric hub end-wall on the stator of a single stage high subsonic axial-flow compressor. In order to obtain a state-of-the-art stator non-axisymmetric hub end-wall configuration fulfilling the requirements for higher efficiency and total pressure ratio, an automated multi-objective optimizer was used, in conjunction with 3D-RANS-flow simulations. For the purpose of quantifying the effect of the optimal stator non axis-symmetric hub contouring on the compressor performance and its effects on the subsonic axial-flow compressor stator end-wall flow field structure, the coupled flow of the compressor stage with the baseline, axisymmetric and the non-axisymmetric stator hub end-wall was simulated with a state-of-theart multi-block flow 3D CFD solver. Based on the CFD simulations, the optimal compressor hub end-wall configuration is expected to increase the peak efficiency by approximately 2.04 points and a slight increase of the total pressure ratio. Detailed analyses of the numerical flow visualization at the hub have uncovered the different hub flow topologies between the cases with axisymmetric and non-axisymmetric hub end-walls. It was found that that the primary performance enhancement afforded by the non-axisymmetric hub end-wall is a result of the end-wall flow structure modification. Compared to the smooth wall case, the non-axisymmetric hub end-wall can reduce the formation and development of in-passage secondary flow by aerodynamic loading redistribution.

  9. Dual rotor single- stator axial air gap PMSM motor/generator drive for high torque vehicles applications

    NASA Astrophysics Data System (ADS)

    Tutelea, L. N.; Deaconu, S. I.; Boldea, I.; Popa, G. N.

    2014-03-01

    The actual e - continuously variable transmission (e-CVT) solution for the parallel Hybrid Electric Vehicle (HEV) requires two electric machines, two inverters, and a planetary gear. A distinct electric generator and a propulsion electric motor, both with full power converters, are typical for a series HEV. In an effort to simplify the planetary-geared e-CVT for the parallel HEV or the series HEV we hereby propose to replace the basically two electric machines and their two power converters by a single, axial-air-gap, electric machine central stator, fed from a single PWM converter with dual frequency voltage output and two independent PM rotors, destined for hybrid electric vehicles (HEV) and military vehicles applications. The proposed topologies and the magneto-motive force analysis are the core of the paper.

  10. Low-Noise Potential of Advanced Fan Stage Stator Vane Designs Verified in NASA Lewis Wind Tunnel Test

    NASA Technical Reports Server (NTRS)

    Hughes, Christopher E.

    1999-01-01

    With the advent of new, more stringent noise regulations in the next century, aircraft engine manufacturers are investigating new technologies to make the current generation of aircraft engines as well as the next generation of advanced engines quieter without sacrificing operating performance. A current NASA initiative called the Advanced Subsonic Technology (AST) Program has set as a goal a 6-EPNdB (effective perceived noise) reduction in aircraft engine noise relative to 1992 technology levels by the year 2000. As part of this noise program, and in cooperation with the Allison Engine Company, an advanced, low-noise, high-bypass-ratio fan stage design and several advanced technology stator vane designs were recently tested in NASA Lewis Research Center's 9- by 15-Foot Low-Speed Wind Tunnel (an anechoic facility). The project was called the NASA/Allison Low Noise Fan.

  11. Streakline flow visualization study of a horseshoe vortex in a large-scale, two-dimensional turbine stator cascade

    NASA Technical Reports Server (NTRS)

    Gaugler, R. E.; Russell, L. M.

    1979-01-01

    Neutrally bouyant helium-filled bubbles were observed as they followed the streamlines in a horseshoe vortex system around the vane leading edge in a large scale, two dimensional, turbine stator cascade. Inlet Reynolds number, based on true chord, ranged between 100,000 to 300,000. Bubbles were introduced into the endwall boundary layer through a slot upstream of the vane leading edge. The paths of the bubbles were recorded photographically as streaklines on 16 mm movie film. Individual frames from the film were selected, and overlayed to show the details of the horseshoe vortex around the leading edge. The transport of the vortex across the passage near the leading edge is clearly seen when compared to the streaks formed by bubbles carried in the main stream. Limiting streamlines on the endwall surface were traced by the flow of oil drops.

  12. Investigation of Turbines Suitable for Use in a Turbojet Engine Wtih High Compressor Pressure Ratio and Low Compressor-tip Speed V : Experimental Performance of Two-stage Turbine with Downstream Stator

    NASA Technical Reports Server (NTRS)

    Davison, Elmer H; Petrash, Donald A; Schum, Harold J

    1951-01-01

    An experimental investigation of a highly loaded two-stage turbine with a downstream stator revealed that (1) at equivalent design work and speed the brake internal efficiency was 0.81 and the maximum efficiency obtained was 0.85, and (2) the downstream stator left very little energy in the form of tangential velocity in the gas and, in general, performed well with 0.78 recovery being obtained at equivalent design work and speed.

  13. Single-stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors. Part 3: Data and performance for stage C

    NASA Technical Reports Server (NTRS)

    Brent, J. A.; Clemmons, D.

    1972-01-01

    Stage C, comprised of tandem-airfoil rotor C and tandem-airfoil stator B, was designed and tested to establish performance data for comparison with the performance of conventional single-airfoil blading. Velocity diagrams and blade leading and trailing edge metal angles selected for the conventional rotor and stator blading were used in the design of the tandem blading. The rotor had an inlet hub/tip ratio of 0.8 and a design tip velocity of 757 ft/sec. At design equivalent rotor speed, rotor C achieved a maximum adiabatic efficiency of 91.8% at a pressure ratio of 1.31. The stage maximum adiabatic efficiency was 86.5% at a pressure ratio of 1.31.

  14. The torque ripple reduction of a concentrated winding synchronous reluctance motor according to stator and rotor structure variations using response surface methodology

    NASA Astrophysics Data System (ADS)

    Choi, Yun-Chul; Lee, Jung-Ho; Hong, Jung Pyo

    2008-04-01

    This paper deals with optimum design criteria to minimize the torque ripple of a concentrated winding synchronous reluctance motor (SynRM) using response surface methodology (RSM). The feasibility of using RSM with the finite element method in practical engineering problem is investigated with computational examples and comparison between the fitted response and the results obtained from an analytical solution according to the design variables of stator and rotor in concentrated winding SynRM (6slot).

  15. A novel technique for estimation and control of stator flux of a salient-pole PMSM in DTC method based on MTPF

    Microsoft Academic Search

    Jawad Faiz; S. Hossein Mohseni-Zonoozi

    2003-01-01

    A permanent-magnet synchronous machine (PMSM) can be controlled using the direct torque control (DTC) technique in three different ways, i.e., by controlling flux, reactive torque and rotor d-axis current. Frequently, the DTC technique controls the speed of the motor by controlling stator flux with the aim of obtaining an optimal torque. A varying flux, proportional to the torque, may be

  16. Two-dimensional analytical and experimental performance comparison for a compressor stator section with D-factor of 0.47

    NASA Technical Reports Server (NTRS)

    Sanger, N. L.

    1973-01-01

    Analytically computed flow parameters were compared to measured values for the midspan double-circular-arc section of a stator in subsonic flow. Analytical procedures included calculations for inviscid flow, blade surface boundary layers, and loss coefficients. Comparisons were made at three incidence angles. Methods for prescribing the exit fluid angle in inviscid flow calculations were investigated. Measured loss coefficients were compared to calculated values. Two methods for predicting performance involving iterative use of ideal flow and boundary layer calculations were investigated.

  17. High-loading low-speed fan study. 4: Data and performance with redesign stator and including a rotor tip casing treatment

    NASA Technical Reports Server (NTRS)

    Harley, K. G.; Odegard, P. A.; Burdsall, E. A.

    1972-01-01

    A single stage fan with a rotor tip speed of 1000 ft/sec(304.8 m/sec) and a hub-to-tip ratio of 0.392 was retested with a redesigned stator. Tests were conducted with uniform inlet, tip-radial, hub-radial, and circumferential inlet distortions. With uniform inlet flow, stall margin was improved 12 percentage points above that with the original stator. The fan demonstrated an efficiency of 0.883 and a stall margin of 15 percent at a pressure ratio of 1.488 and a specific flow of 41.17 lb/sec/sq ft. Tests were also made with a redesigned casing treatment consisting of skewed slots over the rotor blade tips. This casing treatment gave a 7 percentage point improvement in stall margin when tested with tip radial distortion (when the rotor tip initiated stall). Noise measurements at the fan inlet and exit indicate no effect from closing the stator 10 degrees, nor were there measurable effects from adding skewed slots over the blade tips.

  18. Development and testing of a 2.5 kW synchronous generator with a high temperature superconducting stator and permanent magnet rotor

    NASA Astrophysics Data System (ADS)

    Qu, Timing; Song, Peng; Yu, Xiaoyu; Gu, Chen; Li, Longnian; Li, Xiaohang; Wang, Dewen; Hu, Boping; Chen, Duxing; Zeng, Pan; Han, Zhenghe

    2014-04-01

    High temperature superconducting (HTS) armature windings have the potential for increasing the electric loading of a synchronous generator due to their high current transport capacity, which could increase the power density of an HTS rotating machine. In this work, a novel synchronous generator prototype with an HTS stator and permanent magnet rotor has been developed. It has a basic structure of four poles and six slots. The armature winding was constructed from six double-pancake race-track coils with 44 turns each. It was designed to deliver 2.5 kW at 300 rpm. A concentrated winding configuration was proposed, to prevent interference at the ends of adjacent HTS coils. The HTS stator was pressure mounted into a hollow Dewar cooled with liquid nitrogen. The whole stator could be cooled down to around 82 K by conduction cooling. In the preliminary testing, the machine worked properly and could deliver 1.8 kW power when the armature current was 14.4 A. Ic for the HTS coils was found to be suppressed due to the influence of the temperature and the leakage field.

  19. The Acoustic Influence of Cell Depth on the Rotordynamic Characteristics of Smooth-Rotor/Honeycomb-Stator Annular Gas Seals

    NASA Technical Reports Server (NTRS)

    Childs, Dara W.

    1996-01-01

    A two-control volume is employed for honeycomb-stator/smooth-rotor seals, with a conventional control-volume used for the through flow and a 'capacitance accumulator' model for the honeycomb cells. The control volume for the honeycomb cells is shown to cause a dramatic reduction in the effective acoustic velocity of the main flow, dropping the lowest acoustic frequency into the frequency range of interest for rotordynamics. In these circumstances, the impedance functions for the seals can not be modeled with conventional (frequency-independent) stiffness, damping, and mass coefficients. More general transfer functions are required to account for the reaction forces, and calculated here as a lead-lag term for the direct force function and a lag term for the cross-coupled function. These first order functions are simple compared to transfer functions for magnetic bearings or foundations, For synchronous response to imbalance, they can be approximated by running-speed-dependent stiffness and damping coefficients in conventional rotordynamic codes. Correct predictions for stability and transient response will require more general algorithms, pressumably using a state-space format.

  20. Magnetic fluid lubrication of bearings each having a porous faced stator and a slider having various shapes

    NASA Astrophysics Data System (ADS)

    Shah, Rajesh C.; Bhat, M. V.

    2004-03-01

    An analysis of slider bearings, each having a porous faced stator, and a slider, having various shapes (e.g., inclined plane, exponential, convex and secant) was made using a magnetic fluid lubricant flowing as per Jenkins flow behaviour. Expressions were obtained for various bearing characteristics. Values of the load capacity, friction on the slider, the coefficient of friction and the position of the centre of pressure were computed in each case and presented in a tabular form for different values of the material parameter. Whatever is the shape of the slider, the load capacity decreased, friction as well as the coefficient of friction increased and the position of the centre of pressure shifted towards the bearing inlet when the material parameter increased. For a convex slider, the load capacity and friction were maximum, and the centre of pressure is the nearest to the inlet for a given material parameter. The coefficient of friction was the greatest and the position of the centre of pressure the farthest from the inlet, while the load capacity was the least in the case of a secant shaped slider. However, friction and the coefficient of friction were found to be the least for an inclined plane slider. Tables 1, Figs 2, Refs 8.

  1. Gate-controlled proton diffusion and protonation-induced ratchet motion in the stator of the bacterial flagellar motor

    PubMed Central

    Nishihara, Yasutaka; Kitao, Akio

    2015-01-01

    The proton permeation process of the stator complex MotA/B in the flagellar motor of Escherichia coli was investigated. The atomic model structure of the transmembrane part of MotA/B was constructed based on the previously published disulfide cross-linking and tryptophan scanning mutations. The dynamic permeation of hydronium/sodium ions and water molecule through the channel formed in MotA/B was observed using a steered molecular dynamics simulation. During the simulation, Leu46 of MotB acts as the gate for hydronium ion permeation, which induced the formation of water wire that may mediate the proton transfer to Asp32 on MotB. Free energy profiles for permeation were calculated by umbrella sampling. The free energy barrier for H3O+ permeation was consistent with the proton transfer rate deduced from the flagellar rotational speed and number of protons per rotation, which suggests that the gating is the rate-limiting step. Structure and dynamics of the MotA/B with nonprotonated and protonated Asp32, Val43Met, and Val43Leu mutants in MotB were investigated using molecular dynamics simulation. A narrowing of the channel was observed in the mutants, which is consistent with the size-dependent ion selectivity. In MotA/B with the nonprotonated Asp32, the A3 segment in MotA maintained a kink whereas the protonation induced a straighter shape. Assuming that the cytoplasmic domain not included in the atomic model moves as a rigid body, the protonation/deprotonation of Asp32 is inferred to induce a ratchet motion of the cytoplasmic domain, which may be correlated to the motion of the flagellar rotor. PMID:26056313

  2. Gate-controlled proton diffusion and protonation-induced ratchet motion in the stator of the bacterial flagellar motor.

    PubMed

    Nishihara, Yasutaka; Kitao, Akio

    2015-06-23

    The proton permeation process of the stator complex MotA/B in the flagellar motor of Escherichia coli was investigated. The atomic model structure of the transmembrane part of MotA/B was constructed based on the previously published disulfide cross-linking and tryptophan scanning mutations. The dynamic permeation of hydronium/sodium ions and water molecule through the channel formed in MotA/B was observed using a steered molecular dynamics simulation. During the simulation, Leu46 of MotB acts as the gate for hydronium ion permeation, which induced the formation of water wire that may mediate the proton transfer to Asp32 on MotB. Free energy profiles for permeation were calculated by umbrella sampling. The free energy barrier for H3O(+) permeation was consistent with the proton transfer rate deduced from the flagellar rotational speed and number of protons per rotation, which suggests that the gating is the rate-limiting step. Structure and dynamics of the MotA/B with nonprotonated and protonated Asp32, Val43Met, and Val43Leu mutants in MotB were investigated using molecular dynamics simulation. A narrowing of the channel was observed in the mutants, which is consistent with the size-dependent ion selectivity. In MotA/B with the nonprotonated Asp32, the A3 segment in MotA maintained a kink whereas the protonation induced a straighter shape. Assuming that the cytoplasmic domain not included in the atomic model moves as a rigid body, the protonation/deprotonation of Asp32 is inferred to induce a ratchet motion of the cytoplasmic domain, which may be correlated to the motion of the flagellar rotor. PMID:26056313

  3. Statistic-based spectral indicator for bearing fault detection in permanent-magnet synchronous machines using the stator current

    NASA Astrophysics Data System (ADS)

    Picot, A.; Obeid, Z.; Régnier, J.; Poignant, S.; Darnis, O.; Maussion, P.

    2014-06-01

    In this paper, an original method for bearing fault detection in high speed synchronous machines is presented. This method is based on the statistical process of Welch's periodogram of the stator currents in order to obtain stable and normalized fault indicators. The principle of the method is to statistically compare the current spectrum to a healthy reference so as to quantify the changes over the time. A statistic-based indicator is then constructed by monitoring specific harmonic family. The proposed method was tested on two experimental test campaigns for four different speeds and compared to a vibration indicator. The method was evaluated using a rigorous performance evaluation metric. A threshold evaluation was performed and shows that the proposed method is very tolerant to the machine speed. Thus, the use of a unique fault threshold whatever the speed can be considered. Results showed excellent agreement as compared with the vibration indicator, with an overall correlation of r=0.74 and only 4% of false alarms. Performance demonstrated by this novel method was superior to those of a classical energy-based indicator in terms of correlation with the vibration indicator and detection stability. Moreover, results also showed a better robustness of the proposed method since good performance can be obtained with the same detection threshold whatever the speed or the measure campaign whereas it needs to be redefined for each case with the classical indicator. This work shows the advantages of a statistic-based approach in order to increase the robustness of bearing fault detection in permanent-magnet synchronous machines.

  4. Moteurs piézo-électriques à onde progressive : I. Modélisation de la conversion d'énergie mécanique à l'interface stator/rotor

    NASA Astrophysics Data System (ADS)

    Minotti, P.; Le Moal, P.; Buchaillot, L.; Ferreira, A.

    1996-10-01

    The modeling of traveling wave type piezoelectric motors involves a large variety of mechanical and physical phenomena and therefore leads to numerous approaches and models. The latter, mainly based on phenomenological and numerical (based on Finite Element Method) analyses, are not suitable for current objectives oriented toward the development of efficient C.A.D. tools. As a result, an attempt is done to investigate analytical approaches, in order to theoretically model the mechanical energy conversion at the stator/rotor interface. This paper is the first in a serie of three articles devoted to the modeling of such rotative motors. After a short description of the operating principles specific to the piezomotors, the mechanical and tribological assumptions made for the driving mechanism of the rotor are briefly described. Then it is shown that the kinematic and dynamic modeling of the stator, combined with the static representation of the stator/rotor interface, gives an efficient way in order to perform the calculation of the loading characteristics of the driving shaft. Finally, the specifications of a new software named C.A.S.I.M.M.I.R.E., which has been recently developed on the basis of our earlier mechanical modeling, are described. In the last of these three papers, the theoretical simulations performed on SHINSEI Japanese motors will show to be close to the experimental data and that the results reported in this paper will lead to the structural optimization of future traveling wave ultrasonic motors. La modélisation des moteurs piézo-électriques à onde progressive implique une grande variété de phénomènes physiques et mécaniques. Cette variété conduit à des approches et modèles tout aussi nombreux et variés, qui reposent principalement sur des analyses phénoménologiques et numériques (Méthode Élements Finis), et ne permettent pas de répondre aux éxigences actuelles concernant le développement d'outils C.A.O. performants. Cette nécessité nous a conduits à développer une modélisation théorique analytique de la conversion d'énergie à l'interface stator/rotor. Ce papier est le premier d'une série de trois articles consacrés à la modélisation des moteurs piézo-électriques rotatifs. Après une rapide description des principes de fonctionnement de ces piézomoteurs, les hypothèses mécaniques et tribologiques concernant le mécanisme d'entraînement du rotor sont énoncées succinctement. On démontre ensuite que la modélisation cinématique et dynamique du stator, combinée à une représentation statique du comportement à l'interface stator/rotor, autorise l'évaluation des caractéristiques en charge des moteurs à onde progressive. Enfin, le logiciel baptisé C.A.S.I.M.M.I.R.E., récemment développé sur la base de la modélisation mécanique précédente, est présenté puis testé. Dans le dernier article de cette série, nous confirmerons la validité des simulations théoriques issues de ce logiciel, à partir de la caractérisation expérimentale de moteurs japonais de la firme SHINSEI. Ce nouveau logiciel constitue d'ores et déjà un outil performant en vue de l'optimisation des futurs moteurs à onde progressive, et a déjà fait l'objet d'une première exploitation en milieu industriel.

  5. Single-stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors. Part 2: Data and performance for stage A

    NASA Technical Reports Server (NTRS)

    Brent, J. A.

    1972-01-01

    Stage A, comprised of a conventional rotor and stator, was designed and tested to establish a performance baseline for comparison with the results of subsequent tests planned for two tandem-blade stages. The rotor had an inlet hub/tip ratio of 0.8 and a design tip velocity of 757 ft/sec. At design equivalent rotor speed, rotor A achieved a maximum adiabatic efficiency of 85.1 percent at a pressure ratio of 1.29. The stage maximum adiabatic efficiency was 78.6 percent at a pressure ratio of 1.27.

  6. Single-stage evaluation of highly-loaded high-Mach-number compressor stages 5. Data and performance of baseline, corner-blow wall suction and combined corner blow wall suction stator

    NASA Technical Reports Server (NTRS)

    Nikkanen, J. P.; Brooky, J. P.

    1972-01-01

    A single-stage compressor with a rotor tip speed of 1600 ft/sec and a 0.5 hub tip ratio was used to investigate the effects of several stator endwall treatment methods on stage range and performance. These endwall treatment methods consisted of stator corner-blow, annular wall suction upstream of stator leading edge, and combined corner-blow and annular wall suction. The overall stage performance with corner blow was essentially the same as the baseline performance. The performance for the annular wall suction and the combined corner-blow and wall suction showed a reduction in peak efficiency of 2.5 percentage points compared to the baseline data.

  7. Effect of Various Blade Modifications in Performance of a 16-Stage Axial-flow Compressor. IV - Effect on Over-all Performance Characteristics of Decreasing Twelfth through Fifteenth Stage Stator-blade Angles 3 deg and Increasing Stator Angles in the Inlet Stages

    NASA Technical Reports Server (NTRS)

    Hatch, James E.; Medeiros, Arthur A.

    1952-01-01

    The performance of a 16-stage axial-flow compressor, in which two modifications of unloaded inlet stages were combined with loaded exit stages, has been determined. In the first modification the exit stages were loaded by decreasing the twelfth through fifteenth stage stator angles 3 deg. as compared with the blade angles in the original compressor, and the inlet stages were unloaded by increasing the blade angles the following amounts: guide vanes and first-stage stator, 6 deg; second- and third-stage stators, 4 deg.; and fourth-stage stators, 3 deg. The over-all performance of this configuration was compared with that of the compressor with the original blade angles. The peak efficiency was increased at all speeds below design and the weight flow was higher at speeds below 80 percent of design, the same at 80 percent of design, and lower at speeds abovce 80 percent of design. The maximum reduction in weight flow occurred at design speed. The surge limit line was higher at speeds between 75 and 90 percent of design when presented on a pressure ratio against weight flow basis. The second configuration was the same as the first with the exception that the second-, third-, and fourth-stage stator blade angles were the same as in the compressor with the original blade angles. A comparison of the performance of this configuration with that of the compressor with the original blade angles showed the same general trends of changes in performance as the first configuration. Comparisons were made of compressor configurations to show the effects upon the performance of decreased loading in the inlet stages. Below 75 percent of design speed, decreased loading results in increased weight flow and peak efficiency; above 80 percent of design speed, decreased loading in the inlet stages results in decreased weight flow and small changes in peak efficiencies. Between 75 and 90 percent of design the changes in surge weight flow and pressure ratio were such that the surge limit line was raised with decreased loading in the inlet stages when presented as pressure ratio against weight flow.

  8. Component Performance Investigation of J71 Experimental Turbine. Part 2; Internal-Flow Conditions with 97-Percent-Design Stator Areas

    NASA Technical Reports Server (NTRS)

    Rebeske, John J., Jr.; Petrash, Donald A.

    1956-01-01

    An experimental investigation of the internal-flow conditions of a J71 experimental turbine equipped with 97-percent-design stator areas was conducted at equivalent design speed and near equivalent design work. The results of the investigation indicate that the stage work distribution closely approximates design, the actual distribution being 44.1, 33.4, and 22.5 percent for the first, second, and third stages, respectively. The first-, second-, and third-stage efficiencies were 0.894, 0.858, and 0.792, respectively. The first and second stages exhibited loss regions near the hub and tip at the rotor blade outlets. The hub loss region is attributed to stator secondary flows, and a contributing factor to the tip loss region may be the high design diffusion on the rotor blade suction surface near the tip. The loss in the third stage is appreciably greater than that in the first or second stage. The fact that the third rotor is unshrouded and has a nominal tip clearance of 0.120 inch may contribute to the higher loss in the tip region of the third stage.

  9. Effect of Various Blade Modifications on Performance of a 16-Stage Axial-Flow Compressor. III - Effect on Over-All Performance Characteristics on Increasing Stator-Blade Angles in Inlet Stages

    NASA Technical Reports Server (NTRS)

    Medeiros, Arthur A.; Hatch, James E.

    1952-01-01

    The stator-blade angles in the first four stages of a 16-stage axial-flow compressor were increased in order to decrease the angles of attack of these stages, and thereby to improve part-speed performance. The performance of this modified compressor was compared with that of the same compressor with original blade angles.

  10. Blade row dynamic digital compression program. Volume 2: J85 circumferential distortion redistribution model, effect of Stator characteristics, and stage characteristics sensitivity study

    NASA Technical Reports Server (NTRS)

    Tesch, W. A.; Steenken, W. G.

    1978-01-01

    The results of dynamic digital blade row compressor model studies of a J85-13 engine are reported. The initial portion of the study was concerned with the calculation of the circumferential redistribution effects in the blade-free volumes forward and aft of the compression component. Although blade-free redistribution effects were estimated, no significant improvement over the parallel-compressor type solution in the prediction of total-pressure inlet distortion stability limit was obtained for the J85-13 engine. Further analysis was directed to identifying the rotor dynamic response to spatial circumferential distortions. Inclusion of the rotor dynamic response led to a considerable gain in the ability of the model to match the test data. The impact of variable stator loss on the prediction of the stability limit was evaluated. An assessment of measurement error on the derivation of the stage characteristics and predicted stability limit of the compressor was also performed.

  11. Windage Power Loss in Gas Foil Bearings and the Rotor-Stator Clearance of High Speed Generators Operating in High Pressure Environments

    NASA Technical Reports Server (NTRS)

    Bruckner, Robert J.

    2009-01-01

    Closed Brayton Cycle (CBC) and Closed Supercritical Cycle (CSC) engines are prime candidates to convert heat from a reactor into electric power for robotic space exploration and habitation. These engine concepts incorporate a permanent magnet starter/generator mounted on the engine shaft along with the requisite turbomachinery. Successful completion of the long-duration missions currently anticipated for these engines will require designs that adequately address all losses within the machine. The preliminary thermal management concept for these engine types is to use the cycle working fluid to provide the required cooling. In addition to providing cooling, the working fluid will also serve as the bearing lubricant. Additional requirements, due to the unique application of these microturbines, are zero contamination of the working fluid and entirely maintenance-free operation for many years. Losses in the gas foil bearings and within the rotor-stator gap of the generator become increasingly important as both rotational speed and mean operating pressure are increased. This paper presents the results of an experimental study, which obtained direct torque measurements on gas foil bearings and generator rotor-stator gaps. Test conditions for these measurements included rotational speeds up to 42,000 revolutions per minute, pressures up to 45 atmospheres, and test gases of nitrogen, helium, and carbon dioxide. These conditions provided a maximum test Taylor number of nearly one million. The results show an exponential rise in power loss as mean operating density is increased for both the gas foil bearing and generator windage. These typical "secondary" losses can become larger than the total system output power if conventional design paradigms are followed. A nondimensional analysis is presented to extend the experimental results into the CSC range for the generator windage.

  12. Cold-air performance of a 15.41-cm-tip-diameter axial-flow power turbine with variable-area stator designed for a 75-kW automotive gas turbine engine

    NASA Technical Reports Server (NTRS)

    Mclallin, K. L.; Kofskey, M. G.; Wong, R. Y.

    1982-01-01

    An experimental evaluation of the aerodynamic performance of the axial flow, variable area stator power turbine stage for the Department of Energy upgraded automotive gas turbine engine was conducted in cold air. The interstage transition duct, the variable area stator, the rotor, and the exit diffuser were included in the evaluation of the turbine stage. The measured total blading efficiency was 0.096 less than the design value of 0.85. Large radial gradients in flow conditions were found at the exit of the interstage duct that adversely affected power turbine performance. Although power turbine efficiency was less than design, the turbine operating line corresponding to the steady state road load power curve was within 0.02 of the maximum available stage efficiency at any given speed.

  13. Effect of Various Blade Modifications on Performance of a 16-Stage Axial-Flow Compressor. II - Effect on Over-All Performance Characteristics of Increasing Twelfth through Fifteenth Stage Stator-Blade Angles 3 deg

    NASA Technical Reports Server (NTRS)

    Hatch, James E.; Medeiros, Arthur A.

    1952-01-01

    The stator-blade angles in the twelfth through fifteenth stages of a 16-stage axial-flow compressor were increased 3O. The over-all performance of this modified compressor is compared to the performance of the compressor with original blade angles. The matching characteristics of the modified compressor and a two-stage turbine were obtained and compared to those of the compressor with original blade angles and the same turbine.

  14. Measurements of the unsteady flow field within the stator row of a transonic axial-flow fan. I - Measurement and analysis technique

    NASA Technical Reports Server (NTRS)

    Suder, K. L.; Strazisar, A. J.; Adamczyk, J. J.; Hathaway, M. D.; Okiishi, T. H.

    1987-01-01

    This two-part paper presents laser anemometer measurements of the unsteady velocity field within the stator row of a transonic axial-flow fan. The objective is to provide additional insight into unsteady blade-row interactions within highspeed compressors which affect stage efficiency, energy transfer, and other design considerations. Part 1 describes the measurement and analysis techniques used for resolving the unsteady flow field features. The ensemble-average and variance of the measured velocities are used to identify the rotor wake generated and unresolved unsteadiness, respectively. (Rotor wake generated unsteadiness refers to the unsteadiness generated by the rotor wake velocity deficit and the term unresolved unsteadiness refers to all remaining contributions to unsteadiness such as vortex shedding, turbulence, mass flow fluctutions, etc.). A procedure for calculating auto and cross correlations of the rotor wake generated and unresolved unsteady velocity fluctuations is described. These unsteady-velocity correlations have significance since they also result from a decomposition of the Navier-Stokes equations. This decomposition of the Navier-Stokes equations resulting in the velocity correlations used to describe the unsteady velocity field will also be outlined in this paper.

  15. Measurements of the unsteady flow field within the stator row of a transonic axial-flow fan. 1: Measurement and analysis technique

    NASA Technical Reports Server (NTRS)

    Suder, K. L.; Hathaway, M. D.; Okiishi, T. H.; Strazisar, A. J.; Adamczyk, J. J.

    1987-01-01

    This two-part paper presents laser anemometer measurements of the unsteady velocity field within the stator row of a transonic axial-flow fan. The objective is to provide additional insight into unsteady blade-row interactions within high speed compressors which affect stage efficiency, energy transfer, and other design considerations. Part 1 describes the measurement and analysis techniques used for resolving the unsteady flow field features. The ensemble-average and variance of the measured velocities are used to identify the rotor wake generated and unresolved unsteadiness, respectively. (Rotor wake generated unsteadiness refers to the unsteadiness generated by the rotor wake velocity deficit and the term unresolved unsteadiness refers to all remaining contributions to unsteadiness such as vortex shedding, turbulence, mass flow fluctuations, etc.). A procedure for calculating auto and cross correlations of the rotor wake generated and unresolved unsteady velocity fluctuations is described. These unsteady-velocity correlations have significance since they also result from a decomposition of the Navier-Stokes equations. This decomposition of the Navier-Stokes equations resulting in the velocity correlations used to describe the unsteady velocity field will also be outlined in this paper.

  16. Cross-linking of the endogenous inhibitor protein (IF1) with rotor (gamma, epsilon) and stator (alpha) subunits of the mitochondrial ATP synthase.

    PubMed

    Minauro-Sanmiguel, Fernando; Bravo, Concepción; García, José J

    2002-12-01

    The location of the endogenous inhibitor protein (IF1) in the rotor/stator architecture of the bovine mitochondrial ATP synthase was studied by reversible cross-linking with dithiobis(succinimidylpropionate) in soluble F1I and intact F1F0I complexes of submitochondrial particles. Reducing two-dimensional electrophoresis, Western blotting, and fluorescent cysteine labeling showed formation of alpha-IF1, IF1-IF1, gamma-IF1, and epsilon-IF1 cross-linkages in soluble F1I and in native F1F0I complexes. Cross-linking blocked the release of IF1 from its inhibitory site and therefore the activation of F1I and F1F0I complexes in a dithiothreitol-sensitive process. These results show that the endogenous IF1 is at a distance < or = 12 angstroms to gamma and epsilon subunits of the central rotor of the native mitochondrial ATP synthase. This finding strongly suggests that, without excluding the classical assumption that IF1 inhibits conformational changes of the catalytic beta subunits, the inhibitory mechanism of IF1 may involve the interference with rotation of the central stalk. PMID:12678435

  17. Como Lo Hago Yo: Tratamiento Quirurgico Del Mielomeningocele

    PubMed Central

    Portillo, Santiago

    2014-01-01

    En Argentina hay plan de fortificación con ácido fólico. Diagnostico prenatal no siempre es correcto. Cierre según técnica. Cerramos músculo. No favorecemos corpectomía temprana en casos de cifosis. Suturamos la plaqueta. Cerramos el plano muscular. Hidrocefalia: Válvula de derivación, generalmente dentro de los dos primeros meses. Ventriculostomía no está indicada. Chiari II. Laminectomia cervical alta. Siringomielia: Derivación desde la cavidad al peritoneo. PMID:24791219

  18. Gestión del riesgo del cambio (segunda parte)

    Microsoft Academic Search

    Juan Pablo Zorrilla Salgador

    1970-01-01

    Segunda parte del artículo acerca del uso de futuros sobre el tipo de cambio. Esta continuación abarca estrategias, definiciones, metodología y explicaciones sobre todo lo relacionado con el Ratio de cobertura de los futuros y la aparición del riesgo base.

  19. Surface Temperature Measurements from a Stator Vane Doublet in a Turbine Engine Afterburner Flame using Ultra-Bright Cr-Doped GdAlO3 Thermographic Phosphor

    NASA Technical Reports Server (NTRS)

    Eldridge, Jeffrey I.; Jenkins, Thomas P.; Allison, Stephen W.; Wolfe, Douglas E.; Howard, Robert P.

    2013-01-01

    Luminescence-based surface temperature measurements from an ultra-bright Cr-doped GdAlO3 perovskite (GAP:Cr) coating were successfully conducted on an air-film-cooled stator vane doublet exposed to the afterburner flame of a J85 test engine at University of Tennessee Space Institute (UTSI). The objective of the testing at UTSI was to demonstrate that reliable thermal barrier coating (TBC) surface temperatures based on luminescence decay of a thermographic phosphor could be obtained from the surface of an actual engine component in an aggressive afterburner flame environment and to address the challenges of a highly radiant background and high velocity gases. A high-pressure turbine vane doublet from a Honeywell TECH7000 turbine engine was coated with a standard electron-beam physical vapor deposited (EB-PVD) 200-m-thick TBC composed of yttria-stabilized zirconia (YSZ) onto which a 25-m-thick GAP:Cr thermographic phosphor layer was deposited by EB-PVD. The ultra-bright broadband luminescence from the GAP:Cr thermographic phosphor is shown to offer the advantage of over an order-of-magnitude greater emission intensity compared to rare-earth-doped phosphors in the engine test environment. This higher emission intensity was shown to be very desirable for overcoming the necessarily restricted probe light collection solid angle and for achieving high signal-to-background levels. Luminescence-decay-based surface temperature measurements varied from 500 to over 1000C depending on engine operating conditions and level of air film cooling.

  20. The effects of inlet turbulence and rotor/stator interactions on the aerodynamics and heat transfer of a large-scale rotating turbine model. Part 4: Aerodynamic data tabulation

    NASA Technical Reports Server (NTRS)

    Dring, R. P.; Joslyn, H. D.; Blair, M. F.

    1987-01-01

    A combined experimental and analytical program was conducted to examine the effects of inlet turbulence and airfoil heat transfer. The experimental portion of the study was conducted in a large-scale (approx. 5X engine), ambient temperature, rotating turbine model configured in both single-stage and stage-and-a-half arrangements. Heat transfer measurements were obtained using low-conductivity airfoils with miniature thermocouples welded to a thin, electrically heated surface skin. Heat transfer data were acquired for various combinations of low or high inlet turbulence intensity, flow coefficient, first stator-rotor axial spacing, Reynolds number and relative circumferential position of the first and second stators. Aerodynamic measurements obtained include distributions of the mean and fluctuating velocities at the turbine inlet and, for each airfoil row, midspan airfoil surface pressures and circumferential distributions of the downstream steady state pressures and fluctuating velocities. Results include airfoil heat transfer predictions produced using existing 2-D boundary layer computation schemes and an examination of solutions of the unsteady boundary layer equations.

  1. CARACTERSTICAS Y ARTICULACIN DEL ESPACIO DEL MUNDO TERRENAL Y DEL ESPACIO DEL MS ALL

    E-print Network

    Paris-Sud XI, Université de

    1 12/03/2009 CARACTERÍSTICAS Y ARTICULACI�N DEL ESPACIO DEL MUNDO TERRENAL Y DEL ESPACIO DEL MÁS "El tiempo y el espacio en Gonzalo de Berceo"1. El estudio concierne toda la obra, y se centra en la las "herramientas mentales" que son la concepción del tiempo y del espacio. En lo que toca al segundo

  2. Multi-cycle recovery of lactoferrin and lactoperoxidase from crude whey using fimbriated high-capacity magnetic cation exchangers and a novel "rotor-stator" high-gradient magnetic separator.

    PubMed

    Brown, Geoffrey N; Müller, Christine; Theodosiou, Eirini; Franzreb, Matthias; Thomas, Owen R T

    2013-06-01

    Cerium (IV) initiated "graft-from" polymerization reactions were employed to convert M-PVA magnetic particles into polyacrylic acid-fimbriated magnetic cation exchange supports displaying ultra-high binding capacity for basic target proteins. The modifications, which were performed at 25?mg and 2.5?g scales, delivered maximum binding capacities (Qmax ) for hen egg white lysozyme in excess of 320?mg?g(-1) , combined with sub-micromolar dissociation constants (0.45-0.69?µm) and "tightness of binding" values greater than 49?L?g(-1) . Two batches of polyacrylic acid-fimbriated magnetic cation exchangers were combined to form a 5?g pooled batch exhibiting Qmax values for lysozyme, lactoferrin, and lactoperoxidase of 404, 585, and 685?mg?g(-1) , respectively. These magnetic cation exchangers were subsequently employed together with a newly designed "rotor-stator" type HGMF rig, in five sequential cycles of recovery of lactoferrin and lactoperoxidase from 2?L batches of a crude sweet bovine whey feedstock. Lactoferrin purification performance was observed to remain relatively constant from one HGMF cycle to the next over the five operating cycles, with yields between 40% and 49% combined with purification and concentration factors of 37- to 46-fold and 1.3- to 1.6-fold, respectively. The far superior multi-cycle HGMF performance seen here compared to that observed in our earlier studies can be directly attributed to the combined use of improved high capacity adsorbents and superior particle resuspension afforded by the new "rotor-stator" HGMS design. PMID:23335282

  3. Gestión del riesgo del cambio (primera parte)

    Microsoft Academic Search

    Juan Pablo Zorrilla Salgador

    1970-01-01

    A partir de la desaparición del sistema Bretton-Woods, y la libre flotación del\\u000atipo de cambio, el mundo se volvió más susceptible a todo tipo de riesgos.\\u000aEl presente artículo pretende explicar a los gestores financieros o empresarios interesados en el tema de instrumentos financieros derivados, a conocer lo\\u000amás relevante y necesario acerca del uso de futuros sobre el

  4. Estadísticas del cáncer

    Cancer.gov

    Información básica sobre las estadísticas del cáncer, las cuales describen las tendencias en grupos grandes de personas y ofrecen una imagen a través del tiempo de la carga que representa el cáncer en la sociedad.

  5. La regulación del precio del etanol en Colombia. ¿Teoría del interés general o teoría del interés privado?

    Microsoft Academic Search

    Luz Marina Romero Alvarado

    2010-01-01

    El objetivo de este artículo es presentar los resultados del trabajo de investigación en el que la unidad de análisis se delimitó a la regulación del precio del etanol en Colombia, desde la perspectiva de la regulación económica, siguiendo los enfoques de la teoría del interés general versus teoría del interés privado. El desarrollo del trabajo consistió en hallar la

  6. Effect of Various Blade Modifications on Performance of a 16-Stage High-pressure-ratio Axial-flow Compressor.Angles 3 deg. 1; Effect on Over-all Performance Characteristics of Decreasing Twelfth Through Fifteenth State Stator-blade Angles 3 deg

    NASA Technical Reports Server (NTRS)

    Medeiros, Arthur A.; Hatch, James E.; Dugan, James F., Jr.

    1952-01-01

    The stator-blade angles in the twelfth to fifteenth stages of a 16-stage high-pressure-ratio axial-flow compressor were decreased 3 deg The over-all performance of this compressor is compared with the performance of the same compressor with standard blade angles. The matching characteristics of the modified compressor and a two-stage turbine were also obtained and compared with those of the compressor with the original blade angles and the same turbine.

  7. Museo Universitario del Chopo Datos del plan de estudio

    E-print Network

    Islas, León

    periodismo cultural para producir información en los diferentes géneros informativos, para su publicación características del fenómeno informativo, delimitando el campo de acción del periodista cultural. Utilizar los elementos del lenguaje periodístico. Distinguir la estructura de los diferentes géneros informativos

  8. Ácaros del mango

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Los ácaros constituyen un grupo abundante y diverso que ocupa diferentes hábitats en árboles frutales y la estructura y disposición del follaje y ramas del mango, contribuyen significativamente a que se presente gran diversidad de ácaros benéficos y dañinos asociados a esta especie frutal. En Colomb...

  9. en Fisioterapia del Deporte

    E-print Network

    Rey Juan Carlos, Universidad

    Experto en Fisioterapia del Deporte III Edición RESERVA DE PLAZAY MATRÍCULA Título: Experto en Fisioterapia del Deporte Precio de título: 1.800 Plazo de preinscripción: hasta 15 de Octubre 2014 Nº de que se encuentra matriculado en cuarto curso de grado en fisioterapia (en caso de alumnos

  10. Determinación del perfil instrumental del EBASIM

    NASA Astrophysics Data System (ADS)

    Nieva, M. F.; Rodriguez, M. V.; Pintado, O. I.

    Se calcula el perfil instrumental para el telescopio de 2,15m del CASLEO con EBASIM. Para ello se usaron flats de cielo y el espectro solar FTS de Kurucz. El método, que se puede utilizar para otras configuraciones instrumentales, es convolucionar ambos espectros para obtener los coeficientes de corrección.

  11. TEORÍAS DEL DESARROLLO A PRINCIPIOS DEL SIGLO XXI

    Microsoft Academic Search

    AMARTYA SEN

    1 La evolución de las ideas no sigue el curso de los siglos. Es más, en el transcurso del siglo XX hemos presenciado cambios radicales en lo que a teoría del desarrollo se refiere. Ni siquiera es indispensable definir los siglos de acuerdo con la clasificación del calendario, de cero a noventa y nueve. En su célebre discurso del 8

  12. Chirurgia Videoassistita del Diaframma

    Microsoft Academic Search

    Francesco Quarantotto; Giorgio Cavallesco; Gaetano Rocco

    La chirurgia videoassistita del diaframma rappresenta una naturale evoluzione della videotoracoscopia, volta a superare le\\u000a difficoltà tecniche di quest’ultima; questa metodica si pone come compromesso tra la videotoracoscopia e la toracotomia tradizionale:\\u000a in questo modo il chirurgo ha la possibilità di compiere manovre chirurgiche altrimenti di difficile esecuzione col solo accesso\\u000a toracoscopico, godendo di un’ottima visione del campo operatorio e

  13. -DERECHO PBLICO DEL ESTADO AUTONMICO La implantacin del Mster universitario en Derecho Pblico del Estado Autonmico

    E-print Network

    Rey Juan Carlos, Universidad

    - DERECHO PÚBLICO DEL ESTADO AUTONÓMICO La implantación del Máster universitario en Derecho Público del Estado Autonómico extinguirá el Máster Oficial en Derecho Autonómico y Local. Por esta razón se materias del Máster Oficial en Derecho Autonómico y Local. Los estudiantes que comenzaron el Máster Oficial

  14. Estudio del CH interestelar

    NASA Astrophysics Data System (ADS)

    Olano, C.; Lemarchand, G.; Sanz, A. J.; Bava, J. A.

    El objetivo principal de este proyecto consiste en el estudio de la distribución y abundancia del CH en nubes interestelares a través de la observación de las líneas hiperfinas del CH en 3,3 GHz. El CH es una molécula de amplia distribución en el espacio interestelar y una de las pocas especies que han sido observadas tanto con técnicas de radio como ópticas. Desde el punto de vista tecnológico se ha desarrollado un cabezal de receptor que permitirá la realización de observaciones polarimétricas en la frecuencia de 3,3 GHz, con una temperatura del sistema de 60 K y un ancho de banda de 140 MHz, y que será instalado en el foco primario de la antena parabólica del IAR. El cabezal del receptor es capaz de detectar señales polarizadas, separando las componentes de polarización circular derecha e izquierda. Para tal fin el cabezal consta de dos ramas receptoras que amplificarán la señal y la trasladarán a una frecuencia más baja (frecuencia intermedia), permitiendo de esa forma un mejor transporte de la señal a la sala de control para su posterior procesamiento. El receptor además de tener características polarimétricas, podrá ser usado en el continuo y en la línea, utilizando las ventajas observacionales y de procesamiento de señal que actualmente posee el IAR.

  15. Boletín del Centro Mexicano del Instituto Internacional de Teatro (ITT)

    E-print Network

    1986-04-01

    96 LATIN AMERICAN THEATRE REVIEW Boletín del Centro Mexicano del Instituto Internacional de Teatro (ITT) This tri-lingual (Spanish, English, French) bulletin about recent theatre activities in Mexico is published in collaboration with the Centro... for Children and Youth, University Theatre, the work of the Teatro del Instituto Mexicano del Seguro Social, and a list of productions for the 1984 season. It is hoped that the bulletin will help make Mexican theatre better known both nationally...

  16. Como Solicitar Los Beneficios del Seguro del Desempleo Transcripcin

    E-print Network

    Como Solicitar Los Beneficios del Seguro del Desempleo Transcripción Bienvenido a uno de los de desempleo en California, usted ha venido al lugar correcto, y aquí estamos para servirle. Este es a recibir sus beneficios del desempleo. Cuando usted hace una llamada u oprime su botón en su computadora

  17. Instantánea del cáncer de estómago

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de estómago; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  18. Instantánea del cáncer de ovario

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de ovario; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  19. Instantánea del cáncer de páncreas

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de páncreas; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  20. The dynamic stator stalk of rotary ATPases

    PubMed Central

    Stewart, Alastair G.; Lee, Lawrence K.; Donohoe, Mhairi; Chaston, Jessica J.; Stock, Daniela

    2012-01-01

    Rotary ATPases couple ATP hydrolysis/synthesis with proton translocation across biological membranes and so are central components of the biological energy conversion machinery. Their peripheral stalks are essential components that counteract torque generated by rotation of the central stalk during ATP synthesis or hydrolysis. Here we present a 2.25-Å resolution crystal structure of the peripheral stalk from Thermus thermophilus A-type ATPase/synthase. We identify bending and twisting motions inherent within the structure that accommodate and complement a radial wobbling of the ATPase headgroup as it progresses through its catalytic cycles, while still retaining azimuthal stiffness necessary to counteract rotation of the central stalk. The conformational freedom of the peripheral stalk is dictated by its unusual right-handed coiled-coil architecture, which is in principle conserved across all rotary ATPases. In context of the intact enzyme, the dynamics of the peripheral stalks provides a potential mechanism for cooperativity between distant parts of rotary ATPases. PMID:22353718

  1. Experimental determination of stator endwall heat transfer

    NASA Technical Reports Server (NTRS)

    Boyle, Robert J.; Russell, Louis M.

    1989-01-01

    Local Stanton numbers were experimentally determined for the endwall surface of a turbine vane passage. A six vane linear cascade having vanes with an axial chord of 13.81 cm was used. Results were obtained for Reynolds numbers based on inlet velocity and axial chord between 73,000 and 495,000. The test section was connected to a low pressure exhaust system. Ambient air was drawn into the test section, inlet velocity was controlled up to a maximum of 59.4 m/sec. The effect of the inlet boundary layer thickness on the endwall heat transfer was determined for a range of test section flow rates. The liquid crystal measurement technique was used to measure heat transfer. Endwall heat transfer was determined by applying electrical power to a foil heater attached to the cascade endwall. The temperature at which the liquid crystal exhibited a specific color was known from a calibration test. Lines showing this specific color were isotherms, and because of uniform heat generation they were also lines of nearly constant heat transfer. Endwall static pressures were measured, along with surveys of total pressure and flow angles at the inlet and exit of the cascade.

  2. Ceramic turbine stator vane and shroud support

    DOEpatents

    Glenn, Robert G. (Lower Moreland Township, Montgomery County, PA)

    1981-01-01

    A support system for supporting the stationary ceramic vanes and ceramic outer shrouds which define the motive fluid gas path in a gas turbine engine is shown. Each individual segment of the ceramic component whether a vane or shroud segment has an integral radially outwardly projecting stem portion. The stem is enclosed in a split collet member of a high-temperature alloy material having a cavity configured to interlock with the stem portion. The generally cylindrical external surface of the collet engages a mating internal cylindrical surface of an aperture through a supporting arcuate ring segment with mating camming surfaces on the two facing cylindrical surfaces such that radially outward movement of the collet relative to the ring causes the internal cavity of the collet to be reduced in diameter to tightly engage the ceramic stem disposed therein. A portion of the collet extends outwardly through the ring segment opposite the ceramic piece and is threaded for receiving a nut and a compression washer for retaining the collet in the ring segment under a continuous biasing force urging the collet radially outwardly.

  3. Annular stator structure for a rotary machine

    SciTech Connect

    Chaplin, G.F.; Lucas, A.W. Jr.

    1988-02-02

    In an axial flow turbofan gas turbine engine of the type having an axis Ar and being dividable into four quadrants about the axis Ar, an engine casing extending circumferentially about the axis Ar, a fan casing spaced radially outwardly from the engine casing leaving an annular flow path for working medium gases extending circumferentially therebetween, and struts extending from the engine casing to the fan casing across the working medium flow path, each strut being attached to the fan casing at one end and to the engine casing at the other end, the improvement is described which comprises: an array of guide vanes extending radially across the working medium flow path and disposed about the axis Ar such that each quadrant has at least one of the guide vanes disposed in the quadrant, each of the guide vanes being attached to the engine casing and being attached to the fan casing, each of the guide vanes having a free length and having an installed length at installation and under non-operative conditions which is greater than the free length such that under normal operative conditions the guide vanes are placed in tension, the engine casing is placed in tension, and the fan casing is placed in compression.

  4. valorizzazione e fruizione del

    E-print Network

    Di Pillo, Gianni

    prevista per il Museo Orto Botanico di Roma, destinata all'educazione ambientale e alla "citizen science dati sulla biodiversità; un' app per Smartphone e Tablet dedicata alla fruizione del patrimonio storico della Biodiversità. Smartphone e tablet Il Progetto "SmartEcoPhone" ha realizzato una cross platform app

  5. Fisiología del crecimiento

    Microsoft Academic Search

    Arlan L. Rosenbloom

    2007-01-01

    ExtractoEl crecimiento humano es un proceso dinámico y complejo que comienza con la fertilización del óvulo y se completa con la fusión de las epífisis y las metáfisis de los huesos largos, que caracteriza la terminación de la adolescencia. El crecimiento ocurre en fases, con características distintivas en términos de influencias dominantes derivadas de factores y patrones genéticos, ambientales\\/nutricionales y

  6. Nevado del Huila, Columbia

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Nevado del Huila Volcano in Colombia is actually a volcanic chain running north to south, capped by a glacier. With peaks ranging in height from 2,600 to 5,780 meters (8,530 to 18,960 feet), Nevado del Huila is a stratovolcano composed of alternating layers of hardened lava, solidified ash, and volcanic rocks. Its first recorded eruption occurred in the mid-sixteenth century. The long-dormant volcano erupted again in mid-April 2007. A few months before the eruption, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of Nevado del Huila, on February 23, 2007. In this image, the bright white area just east of the central summit is ice. Immediately west of the summit are bare rocks, appearing as blue-gray. West of those rocks, white reappears, but this patch of white results from clouds hovering in the nearby valley. In the east, the colors turn to brown (indicating bare rock) and bright green (indicating vegetation). ASTER photographed Nevado del Huila near the end of a long phase of quietude. On April 17, 2007, local authorities recorded seismic activity associated with rock fracturing on the volcano's central summit, according to the ReliefWeb Website. Activity intensified the following day with an eruption and mudflows, forcing thousands of nearby residents to evacuate. As the Associated Press reported, the eruption caused avalanches and floods that wiped away both houses and bridges. It marked the volcano's first recorded eruption since the Spanish colonized the area five centuries earlier. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  7. PROGRAMA PROFESORES PRECIO DEL CURSO

    E-print Network

    PROGRAMA PROFESORES PRECIO DEL CURSO 300,00 (exento I.V.A) (5 becas para estudiantes de doctorado apertura del curso. 10'00 h Cementos alcalinos: Introducción 11'00 h Café. 11,30 h Activación alcalina de (2011 ­ 2012) CURSO DE POSTGRADO DEL CSIC 20 A 21 de Marzo de 2012 Organizado por: INSTITUTO DE CIENCIAS

  8. Festival del Sur '98

    E-print Network

    Má rquez Montes, Carmen

    1999-04-01

    clásico de Rojas se encarna en el actor y hace un recorrido por su historia, rememorando su nacimiento y las diversas etapas de éxito u olvido en su devenir; asimismo menciona los actores que le han interpretado y su opinión sobre ellos. Sobresale en... Angélica en el umbral del cielo de Eduardo Amor; La República con Chatarra, obra de creación colectiva; Clapso con Marea, espectáculo de danza; y Limundi con Fagolera, espectáculo de calle, con el fuego como nexo de unión. Las Palmas de Gran Canaria...

  9. AAnnuuaarriioo Universidad Nacional del Sur

    E-print Network

    Maguitman, Ana Gabriela

    Doctor Hugo Laborde Secretario del Consejo Superior Universitario Abogado Diego Duprat Secretario General Académico Doctor Marcelo Villar Secretario General de Ciencia y Tecnología Doctor Alfredo Juan Secretario

  10. Paul Cockshott, Allin Cottrell Las ideas importantes del socialismo del

    E-print Network

    Cockshott, W. Paul

    : Acabó con la polarización de la sociedad en ricos y pobres Acabó con el desempleo Logró progreso ventajas: Alguna reducción en las desigualdades del ingreso Reducción del desempleo Progreso económico para diferencias grandes entre unos billonarios y los trabajadores ordinarios seguían. El desempleo masivo

  11. Las teorías del desarrollo a principios del siglo XXI

    Microsoft Academic Search

    Amartya Sen

    1998-01-01

    Este artículo revisa el estado actual de las teorías del desarrollo teniendo en cuenta la experiencia histórica y la evolución interna de la teoría desde finales de la Segunda Guerra Mundial. Aunque la comprensión del desarrollo ha mejorado, se han hecho generalizaciones indebidas y extraído lecciones infundadas. Sen rechaza la oposición entre Estado y mercado y entre planificación y rentabilidad,

  12. Manejo Ambiental del Asma Peditrica

    E-print Network

    Bezrukov, Sergey M.

    Manejo Ambiental del Asma Pediátrica Guías para el Personal de Salud #12;Aprobado por Ambulatory Nurse Practitioners #12;Manejo Ambiental del Asma Pediátrica Guías para el Personal de Salud Agosto National Institute of Environmental Health Sciences. #12;Iniciativa para el Asma Pediátrica Comité

  13. EL ORIGEN BIOLÓGICO DEL DERECHO

    Microsoft Academic Search

    Axel P. Retana-Salazar

    En este trabajo se aborda el posible origen evolutivo del derecho como una consecuencia del desarrollo social de nuestra especie. Otras especies con sistemas sociales similares presentan varias reglas para la convivencia en grupo. Algunas de estas reglas son comunes en todas las especies con comportamiento social. El desarrollo de la sociobiología en las últimas décadas es una herramienta importante

  14. Metodologa de investigacin para la restauracin del

    E-print Network

    Rey Benayas, José María

    DESARROLLO SOSTENIBLE DEL MEDIO RURAL LEY DE 28 DE MAYO DE 2007, DE SUELO #12;CAMBIOS EN LOS USOS DEL SUELO sostenible es reivindicar el paisaje como la materialización del encuentro entre el territorio, la acción

  15. Monitor de Pilates Programa del curso

    E-print Network

    Escolano, Francisco

    1 Monitor de Pilates Programa del curso 1. Bases biomédicas del Pilates (15 HORAS). 1 técnicos y comunicativos: aspectos psicosociales y emocionales. Estructura del curso 50 horas. Número: Fútbol · Profesor Master, Posgrados y Cursos Universidad Europea Madrid, Universidad CAECE, Universidad

  16. Los Logros y las Carencias de las Transferencias de Efectivo Condicionadass: Evaluación del Impacto del Programa Tekoporã del Paraguay

    Microsoft Academic Search

    Fabio Veras Soares; Rafael Perez Ribas; Guilherme Issamu Hirata

    2008-01-01

    El Centro Internacional de Pobreza (CIP), con el apoyo del GTZ y el FNUAP, ha llevado a cabo recientemente una evaluación del impacto del programa piloto de Tekoporã, un programa de transferencias de efectivo condicionadas (CCT, en su sigla inglesa) en Paraguay. Previamente, el CIP analizó el marco lógico del programa y sus dificultades de aplicación, y se evaluaron sus

  17. Alberto del Pozo

    NSDL National Science Digital Library

    The Cuban Heritage Collection of the University of Miami Libraries was a recipient of 17 original illustrations by Alberto del Pozo in 1998 from the Campilli family. "The Oricha Collection" is their gift, and it contains illustrations in pen, crayon, and ink and the collection "pays homage to the primary gods and goddesses that comprise the Afro-Cuban religion of Santer'a." The "Introduction" near the top of the page, is a good place for visitors to start learning about Pozo, who was a Parson's School of Design-trained, Cuban artist who died at the age of 47. The "Biographical Sketch" is worth looking at as well. Examples of his colorful, heavily patterned and symbolism-intensive drawings of Santeria gods and goddesses can be found in the link "Gallery". The description of each drawing is given in English and Spanish. Finally, visitors interested in more information on the Santeria, can look at the "Further Readings" link for authoritative books on the subject.

  18. I Encuentro del Equipo Ejecutivo Vicerrectorado Administrativo

    E-print Network

    Vásquez, Carlos

    Gestión del Capital Humano · Incremento de la eficacia, eficiencia y rendimiento de la DGCH · Mejoramiento de Gestión del Capital Humano · Digitalización de los EXPEDIENTES · Sistema de Información Gestión del Capital Humano METAS 2009-2013 ·Diagnóstico y Reorganización de la DGCH ·Implantación del

  19. NOTES DEL SEMINARI FUNCIONS THETA

    E-print Network

    Travesa, Artur

    NOTES DEL SEMINARI FUNCIONS THETA Barcelona, 2003 #12;10 Notes del Seminari de Teoria de Nombres (UB-UAB-UPC) Comitè editorial P. Bayer E. Nart J. Quer #12;FUNCIONS THETA Edició a cura de P. Bayer J-02 ISBN: 84-923250-7-0 #12;iv #12;´Index 1 Funcions theta de Jacobi i corbes el·l´iptiques (I) E. Torres 3

  20. INFORME SOBRE L'APLICACI DEL RGIM DE DEDICACI DEL PROFESSORAT DE LA UPC

    E-print Network

    Casanellas, Marta

    ;1 INFORME AVALUACIÓ DEL RÈGIM DE DEDICACIÓ DEL PDI DE LA UPC Convocatòria 2011 PREÀMBUL En data 24 de juliol realitzar la difusió dels resultats del procés entre el PDI afectat, es varen gestionar les incidències'aquesta fase, són Difusió dels resultats · Total PDI avaluat 1.755 · PDI que va accedir a l'aplicació 1.557 (88

  1. Lazamrsa 18: 45-93 (1997> Los macrolquenes del macizo del Calar del Mundo

    E-print Network

    Herrera, Carlos M.

    resvulu dci viul esucíclicí, ciii csitciitueci ílcir(sxictu de ivís niacrvuiíqoenes del nísucizo ciel 0 Sierra de A iccírcí, A ihacereí Vn el - se d u y uunua dci baliacrgtu de cnn tuulcul dc 126 especies y

  2. Temas y rumbos del teatro rural hispanoamericano del siglo XX.

    E-print Network

    Neglia, Erminio G.

    1971-10-01

    clima y a la posición económica de los campesinos, está en el centro de la acción y, en ocasiones, se humaniza, convirtiéndose en uno de los protagonistas de la obra, v. gr., Por los caminos van los campesinos del nicaragüense Pablo Antonio Cuadra... mayor importancia para el campesino, cuya susceptibilidad en ciertas materias, v. gr., el honor de la mujer, es extremada y distinta de la del hombre que vive en la ciudad. En Por los caminos van los campesinos de Pablo Antonio Cuadra, Sebastián mata...

  3. EL ROL DEL GNERO DENTRO DEL PROCESO DE APRENDIZAJE COLABORATIVO

    E-print Network

    Guerrero, Luis

    de sexo y la forma en que esto afecta las actividades colaborativas. En el presente trabajo se describen los resultados de un experimento desarrollado con el fin de establecer que la diferencia de sexo]. Varios estudios también han demostrado que las diferencias de sexo en el uso del computador están

  4. ¿Macroeconomía mexicana sana? A tres años del “gobierno del empleo”

    Microsoft Academic Search

    Martín Carlos Ramales Osorio

    2009-01-01

    por efectos de la crisis financiera y económica internacional, así como por la aplicación de políticas monetarias y fiscales sumamente restrictivas, a casi tres años de la gestión calderonista los saldos en materia de crecimiento económico y empleo son absolutamente negativos. De cumplirse las previsiones de crecimiento del FMI para este año, que lo ubica en -7.3 por ciento, durante

  5. Instantánea del cáncer de seno (mama)

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de seno (mama); así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  6. conomicas.a.esconomicasaes gua del estudiante

    E-print Network

    Escolano, Francisco

    Calendario Académico 2012/13 ..............................................9 Plan de estudios del Grado en Información del Plan de Estudios............................................................. 11 Asignaturas puedes cambiar la contraseña. La contraseña es personal e intransferible. En caso de olvido

  7. NUEVA CONCEPCIÓN DEL TÉRMINO “INTELIGENCIA”

    Microsoft Academic Search

    Nelky Urrutia Amable

    2010-01-01

    El presente artículo aborda uno de los temas más controversiales del siglo XXI: la influencia de la Inteligencia Emocional en el liderazgo. Este tema reafirma el valor esencial de las habilidades emocionales en todas las funciones y desafíos que deben enfrentar los líderes en el mundo actual; llevándonos a la conclusión de que el éxito profesional está ligado a un

  8. Del crecimiento al desarrollo sostenible

    Microsoft Academic Search

    Lester R. Brown; Sandra Postel; Christopher Flavin

    1992-01-01

    Introducción. Durante gran parte de este siglo los debates económicos se han centrado en la cuestión de si el capitalismo o el socialismo es el mejor procedimiento para la organización de una economía industrial moderna. Esa dsicusión parece haber terminado porque las naciones de Europa Oriental avanzan con rapidez hacia los mecanismos del mercado y la economía soviética se tambalea

  9. Lecciones del de comerciode la

    E-print Network

    Tufts University

    boston University the frederick s. pardee center Universidad nacional aUtónoma de méxico centro de estUdios Derecho de autor y, en su caso, por los tratados internacionales aplicables. IMPRESO EN MÉXICO PRINTED Estudios del Desarrollo Universidad nacional aUtónoma de méxico, Centro de Estudios China-México t

  10. Analisis del sistema Paraguayo de investigacion agropecuaria

    Microsoft Academic Search

    Javier M. Ekboir; Gabriel H. Parellada; Andres Molina; Cesar Duarte

    2003-01-01

    En la d?cada del 90, el Gobierno paraguayo implement?, con poco ?xito, varios planes de reforma del Estado. Actualmente conviven en Paraguay un Estado muy centralizado, con poca capacidad de implementar pol?ticas modernas, y una econom?a muy descentralizada (a veces completamente fuera del control del gobierno y de la polic?a), que evoluciona gracias a las acciones e interacciones de agentes

  11. ASSIGNACI DEL COMPLEMENT BSIC DOCENT CONVOCATRIA 2010

    E-print Network

    Politècnica de Catalunya, Universitat

    ASSIGNACI� DEL COMPLEMENT B�SIC DOCENT CONVOCAT�RIA 2010 Acord núm.113/2011 del Consell de Govern pel qual s'aprova l'assignació del complement bàsic docent. Convocatòria 2010. · Document aprovat per'Avaluació Juliol de 2011 ASSIGNACI� DEL COMPLEMENT B�SIC DOCENT CONVOCAT�RIA 2010 Antecedents El Reial Decret 1086

  12. Consejo Social Principales acuerdos de las sesiones del pleno del Consejo Social durante el curso

    E-print Network

    Oro, Daniel

    Consejo Social Principales acuerdos de las sesiones del pleno del Consejo Social durante el curso del curso 2011-12. Ratificación del acuerdo de la Comisión Permanente sobre premios de investigación para estudiantes de segundo curso de bachillerato y de segundo curso de ciclos for- mativos de grado

  13. PROGRAMA DE MOBILITAT DEL CURS 20__/20__ PROGRAMA DE MOBILIDAD DEL CURSO 20__/20__

    E-print Network

    Oro, Daniel

    PROGRAMA DE MOBILITAT DEL CURS 20__/20__ PROGRAMA DE MOBILIDAD DEL CURSO 20__/20__ 1.2. DNI 0 1 2 3 del període de mobilitat / Duración del período de movilidad Tot el curs / Todo el curso dd mmdd mm aa Programa orientativo Curso de idioma Acte de benvinguda / Sessió informativa / Molt satisfet/a / Muy

  14. Self Interacting Markov chains P. Del Moral

    E-print Network

    Del Moral , Pierre

    Self Interacting Markov chains P. Del Moral Centre INRIA Bordeaux-Sud Ouest S´eminaire de l works with Bercu & Doucet, HAL-INRIA preprints (2008). P. Del Moral (INRIA Bordeaux) INRIA Centre interacting Markov chains 4 Interacting MCMC models P. Del Moral (INRIA Bordeaux) INRIA Centre Bordeaux

  15. Self Interacting Markov chains P. Del Moral

    E-print Network

    Del Moral , Pierre

    Self Interacting Markov chains P. Del Moral Centre INRIA Bordeaux-Sud Ouest Stochastic Analysis of joint works with Bercu & Doucet, HAL-INRIA preprints (2008). P. Del Moral (INRIA Bordeaux) INRIA Centre interacting Markov chains 4 Interacting MCMC models P. Del Moral (INRIA Bordeaux) INRIA Centre Bordeaux

  16. Self Interacting Markov chains P. Del Moral

    E-print Network

    Del Moral , Pierre

    Self Interacting Markov chains P. Del Moral Centre INRIA Bordeaux-Sud Ouest Mathematical Institute works with Bercu & Doucet, HAL-INRIA preprints (2008). P. Del Moral (INRIA Bordeaux) INRIA Centre interacting Markov chains 4 Interacting MCMC models P. Del Moral (INRIA Bordeaux) INRIA Centre Bordeaux

  17. SERVICIO DE DEPORTES NORMATIVA DE USO DEL

    E-print Network

    Escolano, Francisco

    SERVICIO DE DEPORTES NORMATIVA DE USO DEL SERVICIO DE FISIOTERAPIA #12;ÍNDICE EXPOSICIÓN DE MOTIVOS..................................................................................... 4 #12;NORMATIVA DE USO DEL SERVICIO DE FISIOTERAPIA VICERRECTORADO DE CULTURA, DEPORTES Y POLÍTICA LINGÜÍSTICA 3 EXPOSICIÓN DE MOTIVOS La presente normativa pretende regular el uso del Servicio de Fisioterapia

  18. CONCENTRADO DE LA INFORMACIN NOMBRE DEL PROYECTO

    E-print Network

    Bor, Gil

    experiencias de manera sostenible. Para ello, el desarrollo del senderismo en el Parque Ecológico "El Orito1 CONCENTRADO DE LA INFORMACIÓN NOMBRE DEL PROYECTO: DESARROLLO DEL ECOTURISMO EN EL PARQUE Guanajuato por conducto de la sub- Dirección de Ecología, adscrita a la Dirección General de Desarrollo

  19. EVOLUZIONE-WEB -1 -Evoluzione del Web

    E-print Network

    De Antonellis, Valeria

    EVOLUZIONE-WEB - 1 - Evoluzione del Web (fonte prof. Polillo) #12;- 2 - L'evoluzione del web EVOLUZIONE-WEB · Dal primo sito Web (1991) il Web è in continua crescita, e in continua evoluzione tecnologia, il mercato, i comportamenti delle persone · Le fasi della storia del Web: Web 1.0, Web 2.0, il

  20. Lab. 1 -Entorno del laboratorio Lab 1. -Entorno del laboratorio

    E-print Network

    Politècnica de Catalunya, Universitat

    hi ha una descripció general de la configuració de l'entorn que es farà servir per fer les pràctiques les aplicacions que es faran servir habitualment estan a la part de sota de l'escriptori: Aquestes són que farem servir en les pràctiques. ttyS0 e0 e1 e2 #12;Lab. 1 - Entorno del laboratorio 6 1.3. Quagga

  1. Tierra del Fuego, Argentina, South America

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Mitre Peninsula is the easternmost tip of Tierra del Fuego, Argentina, (54.5S, 65.5W). Early winter snow can be seen on this south tip of the Andes Mountains. These same mountains continue underwater to Antarctica. The Strait of Magellan, separating the South American mainland from Tierra del Fuego is off the scene to the north and west, but the Strait of LeMaire, separating Tierra del Fuego from the Isla de los Estados can be seen.

  2. II Taller Centroamericano y del Caribe: Guatemala

    E-print Network

    Bravo-Elizondo, Pedro

    1991-10-01

    FALL 1991 151 II Taller Centroamericano y del Caribe: Guatemala Pedro Bravo-Elízondo En el mes de agosto de 1990, durante la primera asamblea general de la Coordinadora Centroamericana y del Caribe de Teatro, realizada en Tegucigalpa, Honduras..., se acordó que el II Taller se realizara en la ciudad de Guatemala, durante el mes de agosto de 1991. En el Centro Cultural de Guatemala, Miguel Ángel Asturias, se realizó la inauguración el domingo 4 de agosto, con la presentación del Ballet...

  3. Propostes i despropòsits: aspectes del gonellisme

    Microsoft Academic Search

    Guillem Calaforra; Sebastià Moranta

    2005-01-01

    Estudi sobre l'origen i la pervivència del gonellisme. Els autors n'exposen les constants ideològiques, que van del conservadorisme a l'extrema dreta, i fan una completa relació de les seves plataformes de difusió. L'anàlisi minuciosa d'aquest fenomen els porta a considerar el lligam entre el dialectalisme primigeni i el secessionisme anticatalanista que en deriva, així com a constatar la importància del

  4. Roberto Cossa habla del teatro

    E-print Network

    Magnarelli, Sharon

    1987-04-01

    no es un autor que me emocione. Hay gente que con Esperando a Godot ha salido realmente emocionada. A mi más bien me afecta en el sentido intelectual, pero reconozco que en El viejo 134 LATIN AMERICAN THEATRE REVIEW criado con esos dos personajes, en... de inteligencia, y, aparte, de frecuencia del teatro muy grande. Después todo es muy rutinario. Es decir, los críticos acá recurren todos al mismo sistema: hacen el análisis literario de una pieza, después la puesta, después los actores, y al final...

  5. Agenda de dos das de capacitacin (Para uso del representante) Antes del curso Inscripcin

    E-print Network

    curso Inscripción Verificación de la identidad (Licencia de manejar) Formularios de inscripción del: Actividad para romper el hielo Prueba antes del curso 45 minutos Sepa la realidad sobre la enfermedad de

  6. Reglament d'organitzaci i funcionament del departament d'Enginyeria del Terreny, Cartogrfica i Geofsica

    E-print Network

    Yannuzzi Sanchez, Marcelo

    ................................................................................................................................. 3 Article 3. Funcions..................................................................................................................................... 6 Article 14. Funcions del Consell ............................................................................................. 7 Article 16. Delegació de funcions

  7. rgano informativo del Colegio de Ciencias y Humanidades Suplemento especial

    E-print Network

    Islas, León

    Número 3 9 de mayo de 2011 Órgano informativo del Colegio de Ciencias y Humanidades SuplementoCCHSuplementoespecialnúmero3,9demayode20114 La Dirección General del Colegio de Ciencias y Humanidades, a través del elementos básicos del método epidemi- ológico para su aplicación en curso de Ciencias de la Salud, del nivel

  8. Pla Estratgic del Servei d'Alumnat Setembre 2007 1

    E-print Network

    Escolano, Francisco

    Pla Estratègic del Servei d'Alumnat Setembre 2007 1 PLA ESTRATÈGIC DE GESTIÓ SERVEI D'ALUMNAT #12;Pla Estratègic del Servei d'Alumnat Setembre 2007 2 INTRODUCCIÓ La presentació del Pla Estratègic de i l'establiment del marc per al Pla Estratègic de la Universitat d'Alacant. El Pla Estratègic del

  9. Regolamento del Collegio dei Direttori di Dipartimento (DR 769 del 21/12/2010)

    E-print Network

    Guidoni, Leonardo

    Regolamento del Collegio dei Direttori di Dipartimento (DR 769 del 21/12/2010) Titolo I Principi generali ART. 1 Composizione e compiti del Collegio dei Direttori di Dipartimento Il Collegio dei Direttori interdipartimentale con funzioni di raccordo delle politiche per il raggiungimento delle finalità istituzionali dei

  10. PER A UNA PEDAGOGIA DEL LABERINT del text: l'autor, 2008

    E-print Network

    Oro, Daniel

    PER A UNA PEDAGOGIA DEL LABERINT #12;© del text: l'autor, 2008 © de l'edició: Universitat de les Palma DL: PM 1835-2008 #12;PER A UNA PEDAGOGIA DEL LABERINT He triat per a aquesta ocasió reflexionar vostre inclou el camp de la teoria, però també, i en gran manera, el de la pràctica, ja que en pedagogia

  11. Aprovaci de l'actualitzaci del sistema de punts d'activitat acadmica del PDI

    E-print Network

    Yannuzzi Sanchez, Marcelo

    Aprovació de l'actualització del sistema de punts d'activitat acadèmica del PDI Acord núm.150 PDI · Document proposta informat favorablement per la Comissió de Personal i Acció Social celebrada el SISTEMA DE PUNTS D'ACTIVITAT ACADÈMICA DEL PDI Introducció El Consell de Govern va aprovar, en la sessió

  12. Evolución morfodinámica de un enclave montañoso recién deglaciado: el caso del Corral del Veleta (Sierra Nevada), ¿consecuencia del Cambio Climático?

    Microsoft Academic Search

    Antonio Gómez Ortiz; Ferran Salvador Franch; Lothar Schulte; José Juan de Sanjosé Blasco; Alan Atkinson Gordo; David Palacios Estremera

    2008-01-01

    El Corral del Veleta (Sierra Nevada. España) cobija en su seno y bajo manto detrítico hielo glaciar fósil y permafrost alpino, restos, como mínimo, de la Pequeña Edad del Hielo (siglos XV\\/XIX). En la actualidad, estas masas heladas se encuentran en proceso de degradación. Los análisis y controles que desde 2001 se vienen llevando a cabo en un glaciar rocoso

  13. Reseña del VIII Festival Internacional de Teatro

    E-print Network

    Dí az, Né stor Gustavo

    1986-10-01

    , aparecieron de todos los lugares del país los grupos marginales en busca de espacios para mostrar sus realizaciones. En este campo se distinguió el grupo La Tarima de Medellín, dirigido por Elkín Giraldo, que se tomó la audiencia del Festival presentando...

  14. octubre 2007 Resumen de condiciones del

    E-print Network

    Rey Benayas, José María

    incluidos). Compra mínima, 4 unidades: 100 Menos de 10 unidades: 25 / De 10 a 50: 24 / De 51 a 200: 20 para evitar el cambio climático, la crisis ambiental y forestal, del periodista Jordi Bigues; la Guía Práctica de la Energía (IDAE); el dossier Cambia del Ministerio de Medio Ambiente... · Mediante la

  15. de Intercambio Estudiantil UNIVERSIDAD CATLICA DEL URUGUAY

    E-print Network

    Petriu, Emil M.

    Programa de Intercambio Estudiantil UNIVERSIDAD CATÓLICA DEL URUGUAY Nombre de la Universidad Universidad Católica del Uruguay Dámaso Antonio Larrañaga Oficina de Intercambio Estudiantil Secretaría 2738 C.P. 11600 Montevideo Uruguay E-mail interinter@ucu.edu.uy Página Web www.ucu.edu.uy Página Web

  16. SCHEMA STRATIGRAFICO E TETTONICO DEL CARSO ISONTINO

    Microsoft Academic Search

    Maurizio Tentor; Giorgio Tunis; Sandro Venturini

    The stratigraphic section and the tectonic sketch of the Isontino Karst (Gorizia) are herein briefly described . Some important bioevents are recognized and for the first time, aptian deposits are described. Premessa. Il Carso isontino è la propaggine nordoccidentale del Carso triestino-sloveno ed è delimitato ad occidente dall' Isonzo e dalla pianura friulana, a NE dalla Valle del Vipacco e

  17. Investigación sobre la detección del cáncer

    Cancer.gov

    De acuerdo con un estudio en el que participaron más de un millón de mujeres, los investigadores del NCI han determinado que el resultado negativo de una prueba para la detección del VPH proporciona mayor certeza o seguridad frente a riesgos futuros de cáncer de cuello uterino que una prueba de Pap.

  18. ESPECIALIZACIN EN GESTIN AMBIENTAL Objetivo del programa

    E-print Network

    Vásquez, Carlos

    , mitigación y resolución de problemas de carácter ambiental, a fin de contribuir con el desarrollo sostenible Asignaturas Unidades-Crédito Obligatorias (21 UC) Introducción al desarrollo sostenible 3 Evaluación del impacto ambiental del desarrollo 3 Política y legislación ambiental 3 Planificación y gestión ambiental

  19. Prot. n. 56 lordo del b

    E-print Network

    Guidoni, Leonardo

    la dura evisto dall'a nstaurati, ai rinnovi, non cui l'assegn ella durata le ordo annuo gli comun o è stato fru egale del rel è stabilito in arico del ben no, in mater e successiv di cui all assegno) ente essere 011. La dura a legge 240/ quattro ann l dottorato d vemilatrecen al beneficiar

  20. RESOLUCI DEL PLA D'ESTABILITZACI DE PDI Acord nm.186/2011 del Consell de Govern pel qual s'aprova la resoluci del

    E-print Network

    Casanellas, Marta

    RESOLUCIÓ DEL PLA D'ESTABILITZACIÓ DE PDI Acord núm.186/2011 del Consell de Govern pel qual s'aprova la resolució del pla d'estabilització de PDI. · Document proposta informat favorablement per la PROGRAMA D'ESTABILITZACIÓ DEL PDI AMB CONTRACTE TEMPORAL A TEMPS COMPLET DE LA UPC Antecedents El Consell

  1. El teatro dominicano en la década del 80

    E-print Network

    Aybar, Robinson

    1992-04-01

    SPRING 1992 169 El teatro dominicano en la década del 80 Robinson Aybar En el año 1980 un grupo de teatristas reconocidos se reúne en la ciudad de Santiago de los Caballeros para discutir la problemática del teatro dominicano. De dicho... marzo como Día del Teatro en la República Dominicana. El CELCIT también lo había declarado día internacional del teatro. La década del 80 marca en la historia del teatro dominicano precedentes, ya que en 1983 se celebra el primer Festival de la...

  2. Motor bearing damage detection using stator current monitoring

    Microsoft Academic Search

    Randy R. Schoen; Thomas G. Habetler; Farrukh Kamran; R. G. Bartfield

    1995-01-01

    This paper addresses the application of motor current spectral analysis for the detection of rolling-element bearing damage in induction machines. Vibration monitoring of mechanical bearing frequencies is currently used to detect the presence of a fault condition. Since these mechanical vibrations are associated with variations in the physical air gap of the machine, the air gap flux density is modulated

  3. Advanced 3-D viscous SSME turbine rotor stator CFD algorithms

    NASA Technical Reports Server (NTRS)

    Janus, J. Mark; Whitfield, David L.

    1986-01-01

    Current Space Shuttle Main Engine (SSME) high pressure fuel turbopump problems have generated a desire to analyze the flow field of rotating machinery. The status of Computational Fluid Dynamics (CFD) has reached the point that soon the capability to solve unsteady three-dimensional viscous flow fields will be at hand. The work presented involves upgrading the computational efficiency of an operational three-dimensional algorithm. The modifications include algorithm development, algorithm approximation and acceleration, and special coding optimizations. The overall result of these modifications has reduced processing time by nearly 80%.

  4. Active stator winding thermal protection for AC motors

    Microsoft Academic Search

    Pinjia Zhang; Bin Lu; Thomas G. Habetler

    2009-01-01

    AC motors are the main workhorses in process industries. Their malfunction may not only lead to repair or replacement of the motor, but also cause significant financial losses due to unexpected process downtime. Reliable thermal protection of ac motors is crucial for reducing the motor failure rate and prolonging a motor's lifetime. In this paper, conventional thermal protection devices and

  5. A study of viscous flow in stator and rotor passages

    NASA Technical Reports Server (NTRS)

    Sheoran, Y.; Tabakoff, W.

    1982-01-01

    A numerical technique to predict the viscous behavior in the three-dimensional domain of rotating and stationary blade passages is presented. The analysis is based upon the numerical integration of the incompressible Navier-Stokes equations. An approach is taken to combine the three momentum equations and the continuity equation into two sets of vorticity transport-stream function equations. These equations are expressed along families of arbitrarily defined orthogonally intersecting surfaces placed within the blade passage. Unlike the stream surfaces, the arbitrary surfaces allow fluid to flow across. The numerical code employs a nonorthogonal body fitted coordinate system on each of the intersecting surfaces. The solution process involves the iterative combination of the solutions on the two families of intersecting surfaces for a complete solution. The results of flow in thin blade stationary and rotating polar ducts is presented.

  6. Thermal aging properties of mica\\/epoxy stator winding insulations

    Microsoft Academic Search

    Hee Dong Kim; Tae Wan Kim; Jung Hoon Kim; Dou Yol Kang

    1997-01-01

    Electrical properties such as ac current and tan ? of mica\\/epoxy composite materials (130 ?m) were measured using a Schering bridge. Surface conditions were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectra, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) in sound and aged specimens. Both ac current and tan ? of sound specimens were higher than

  7. René Marqués, del absurdo a la realidad

    E-print Network

    Zalacaí n, Daniel

    1978-10-01

    FALL 1978 33 René Marques, del absurdo a la realidad DANIEL ZALACAIN Es evidente en la obra de René Marqués la lucha del autor por tratar de vencer al tiempo, por recuperar un paraíso perdido, ultrajado por el presente. Como artista al fin... desentona con el presente—absurdo y sin sentido. El tiempo, por su parte, se muestra aplastante y devorador, pero no ha podido borrar por completo la existencia del pasado. Es bien palpable que el interior de las casas coloniales que él presenta...

  8. Wind turbine/generator set having a stator cooling system located between stator frame and active coils

    DOEpatents

    Bevington, Christopher M.; Bywaters, Garrett L.; Coleman, Clint C.; Costin, Daniel P.; Danforth, William L.; Lynch, Jonathan A.; Rolland, Robert H.

    2012-11-13

    A wind turbine comprising an electrical generator that includes a rotor assembly. A wind rotor that includes a wind rotor hub is directly coupled to the rotor assembly via a simplified connection. The wind rotor and generator rotor assembly are rotatably mounted on a central spindle via a bearing assembly. The wind rotor hub includes an opening having a diameter larger than the outside diameter of the central spindle adjacent the bearing assembly so as to allow access to the bearing assembly from a cavity inside the wind rotor hub. The spindle is attached to a turret supported by a tower. Each of the spindle, turret and tower has an interior cavity that permits personnel to traverse therethrough to the cavity of the wind rotor hub. The wind turbine further includes a frictional braking system for slowing, stopping or keeping stopped the rotation of the wind rotor and rotor assembly.

  9. La guerra del fin del mundo: historia e invencion en una novela historica

    E-print Network

    Loeffler, Lisa Bowe

    1984-01-01

    41 67 78 IV CONCLUSION 98 APEND ICE NOTAS BIBLIOGRAFXA 104 131 135 VITA 138 CAPITULO I INTRODUCCION La novels mas reciente del escritor peruano contemporaneo Marin 1 Verges Llosa, La uerra del fin del mundo, trata un movimiento reli... novelists y corno critico (Oviedo, Invencion, 310). SegGn el, este terna le fascina porque lo 4 entiende menos cuanto mas lo practica. Puesto que los comentarios de Verges Llosa en sus obras de critics con respecto a otros novelistas se aplican...

  10. conomicas.a.esconomicasaes gua del estudiante

    E-print Network

    Escolano, Francisco

    Académico 2012/13 .......................................... 9 Plan de estudios del Grado en Economía el Plan de Estudios.................................................11 Vicedecanato de Prácticas puedes cambiar la contraseña. La contraseña es personal e intransferible. En caso de olvido

  11. CE Laboratory Del. University of Technology

    E-print Network

    Epema, Dick H.J.

    CE Laboratory Del. University of Technology 1 #12;Outline · The Staff reuse · Spinoff BlueBee 6 Electronic System Level Design (ESL) #12;CE research activities (2. => Technology scaling is posing new architectural, design, test, and computing challenges. 8 Dependable

  12. Departamento de Filosofa del Derecho y Derecho Internacional Privado Presentacin

    E-print Network

    Escolano, Francisco

    Departamento de Filosofía del Derecho y Derecho Internacional Privado Presentación El Departamento de Filosofía del Derecho y Derecho Internacional Privado está compuesto por las siguientes áreas de personalizada, los profesores del Departamento de Filosofía del Derecho y Derecho Internacional Privado ruegan

  13. RESOLUCI DE LA CONVOCATRIA DE LLICNCIES SABTIQUES DEL PDI

    E-print Network

    Politècnica de Catalunya, Universitat

    RESOLUCIÓ DE LA CONVOCATÒRIA DE LLICÈNCIES SABÀTIQUES DEL PDI CURS 2011-2012 Acord núm.110/2011 del Consell de Govern pel qual s'aprova la resolució de la convocatòria de llicències sabàtiques del PDI curs Acadèmic Juliol de 2011 RESOLUCIÓ DE LA CONVOCATÒRIA DE LLICÈNCIES SABÀTIQUES DEL PDI PER AL CURS 2011

  14. RESOLUCI DE LA CONVOCATRIA DE PERMISOS DE MOBILITAT DEL PDI

    E-print Network

    Politècnica de Catalunya, Universitat

    RESOLUCIÓ DE LA CONVOCATÒRIA DE PERMISOS DE MOBILITAT DEL PDI CURS 2011-2012 Acord núm.111/2011 del Consell de Govern pel qual s'aprova la resolució de la convocatòria de permisos de mobilitat del PDI curs Acadèmic Juliol de 2011 RESOLUCIÓ DE LA CONVOCATÒRIA DE PERMISOS DE MOBILITAT EXTERNA DEL PDI 2011

  15. Gonadal dysgenesis in del (18p) syndrome

    SciTech Connect

    Telvi, L.; Ion, A.; Fouquet, F. [Hospital Saint Vincent de Paul, Paris (France)] [and others

    1995-07-17

    We report on a girl with syndromal gonadal dysgenesis and a de novo del (18p). Genetic factors controlling gonadal development are located not only on the X chromosome, but also on autosomes. The present case suggests that one of these genes is situated on 18p. We conclude that patients with del (18p) syndrome should be evaluated for gonadal dysgenesis. 16 refs., 3 figs.

  16. Teatro uruguayo hacia el fin del siglo

    E-print Network

    Pignataro Calero, Jorge

    1993-10-01

    ciudad de Montevideo y, como tal, está sometido a las disposiciones presupuestarias de ingresos y gastos que para un período determinado de tiempo realizan las unidades económicas competentes. b. Nuevos grupos y salas. Sometida a análogas disposiciones... desaparecido Instituto Cultural Uruguayo- Soviético donde abrió sus puertas Arteatro; o el garaje del Instituto Cultural Anglo-Uruguayo convertido en la Sala III de dicha institución. Una de las figuras más prestigiosas y de proyección internacional del medio...

  17. Modificacin de Ttulo de Master en Urbanismo: Planes y proyectos. Del territorio a la ciudad 1. Descripcin del ttulo

    E-print Network

    Fraguela, Basilio B.

    .2. Procedimiento de adaptación, en su caso, de los estudiantes de los estudios existentes al nuevo plan de estudios elaboración del plan de estudio 1 #12;Modificación de Título de Master en Urbanismo: Planes y proyectos. Del general del plan de estudios 5.2. Estructura del plan de estudios 5.3. Descripción detallada de los

  18. Modificacin de Ttulo de Master Universitario en Arquitectura del Paisaje Juana de Vega 1. Descripcin del ttulo

    E-print Network

    Fraguela, Basilio B.

    .2. Procedimiento de adaptación, en su caso, de los estudiantes de los estudios existentes al nuevo plan de estudios elaboración del plan de estudio 1 #12;Modificación de Título de Master Universitario en Arquitectura del general del plan de estudios 5.2. Estructura del plan de estudios 5.3. Descripción detallada de los

  19. Estado del desarrollo del control para la gestin de las funciones de tiempo en

    E-print Network

    Politècnica de Catalunya, Universitat

    Estado del desarrollo del control para la gestión de las funciones de tiempo en Visual TRANSIN necesitamos para VT? -.Discretizar temporalmente (tiempos de control). -.Operar con funciones. -.Encontrar. -.Automático. ·Otros parámetros: -.Número de problema. -.Régimen. -.Intervalos. #12;Funciones de Tiempo ·Origen

  20. De los hacendados a los forestales: Manejo del espacio, dominacidn y explotacidn del bosque

    E-print Network

    Paris-Sud XI, Université de

    uno más entre los numerosos medios de control que supieron y saben usar los dominantes en el medio autonomía, a través del control de los circuitos de créditos, de asesoría técnica, de "programas de el Estado, bajo el impulso del gobernador A. Tejeda. Por otro lado, en cuanto a la propiedad privada

  1. CONVOCATRIA DEL PREMI DE FOMENT DEL MULTILINGISME CURS ACADMIC 2011/2012

    E-print Network

    Geffner, Hector

    Premi de Foment del Multilingüisme (PFM) per al curs 2011-2012, adreçat a estudiants de qualsevol ensenyament de grau de la UPF. El PFM consisteix en un curs de llengua, gratuït, anual o semestral, en Referència per a les llengües (MECR) del Consell d'Europa. El PFM s'ha de fer efectiu amb una matrícula al

  2. CONVOCATRIA DEL PREMI DE FOMENT DEL MULTILINGISME CURS ACADMIC 2010/2011

    E-print Network

    Geffner, Hector

    Premi de Foment del Multilingüisme (PFM) per al curs 2010-2011, adreçat a estudiants de qualsevol ensenyament de grau de la UPF. El PFM consisteix en un curs de llengua, gratuït, d'un nivell, en qualsevol Comú Europeu de Referència per a les llengües (MCER) del Consell d'Europa. El PFM s'ha de fer efectiu

  3. Il Marocco nello scenario agro-alimentare del Bacino del Mediterraneo

    Microsoft Academic Search

    Paolo Cupo

    2000-01-01

    Il Marocco nello scenario agro-alimentare del Bacino del Mediterraneo (di Paolo Cupo) - ABSTRACT: The economy of Morocco is heaving depending on agriculture and, hence, its performance is strongly relating to the exogenous factors such as the weather conditions. For this reason a structural change of the economy should be necessary which, by inducing a shifting of workers among the

  4. Aprendizajes del Informe Especial (SREX) del IPCC Desastres en Amrica Latina y el Caribe

    E-print Network

    sus implicaciones para la sociedad y el desarrollo sostenible. El informe considera los efectos del referencia a este documento se debe hacer de la siguiente manera: Alianza Clima y Desarrollo (2012) La adaptación (véase la Figura 1). El informe considera el rol del desarrollo en fomentar la exposición y la

  5. Los orígenes del Partido del Socialismo Democrático (1989-1993): el ave fénix roja en Alemania

    Microsoft Academic Search

    Ricardo Martín de la Guardia

    2005-01-01

    El Partido del Socialismo Democrático (Partei des Demokratischen Sozialismus), surgido de la descomposición interna del SED (Sozialistiscbe Einbeitspartei Deutschlands), es un caso relevante de adaptación de los partidos únicos en los regímenes comunistas a la democracia plurípar-tidista. Dadas las peculiaridades de la transición en la República Democrática de Alemania, acelerada por su rápida integración en la República Federal, el SED

  6. INTRODUCCI Aquest Pla Estratgic dels Serveis Tcnics d'Investigaci forma part del Pla

    E-print Network

    Escolano, Francisco

    INTRODUCCIÓ Aquest Pla Estratègic dels Serveis Tècnics d'Investigació forma part del Pla Estratègic Sectorial de Gerència, que en el seu moment s'integrarà en el Pla Estratègic General de la Universitat d en procés constant de creixement és de vital importància disposar d'un Pla Estratègic Propi que li

  7. Preguntas y respuestas acerca del Estudio del Tamoxifeno y Raloxifeno (STAR)

    Cancer.gov

    El Estudio del Tamoxifeno y Raloxifeno (STAR, por sus siglas en inglés) es un estudio clínico (un estudio de i nvestigación conducido con voluntarios) diseñado para ver cómo el medicamento raloxifeno (Evista) se compara con el medicamento tamoxifeno (Nolvadex) en reducir la incidencia de cáncer del seno en las mujeres con alto riesgo de desarrollar la enfermedad.

  8. O Diagnostico do Curso de Farmacia da UNIMEP (Diagnosis of the Pharmacy Course of UNIMEP).

    ERIC Educational Resources Information Center

    Fontes, Olney Leite; do Carmo, Thais Adriana; Polacow, Maria Luiza O.; Meneghetti, Rosa Gitana K.; Dedalo, Maria de Fatima Nepomuceno; Alves, Maria Izalina F.; da Silva, Jadson Oliveira; Carvalho, Maria Eliza C.

    2000-01-01

    Reports on the experience of the pharmacy course at UNIMEP (Methodist University of Piracicaba (Brazil)) in diagnosing itself. Offers models for the elaboration of an innovative curriculum which is the desire of those who make up the course. (BT)

  9. COLOMBIA: El IV Festival del Nuevo Teatro

    E-print Network

    Gonzá lez, Patricia E.

    1980-10-01

    a muerte y la ejecución está programada para el día siguiente. Mr. Smith compra al sheriff de Galveston y se lleva al negro, quien entonces asume el nombre de La bala de plata—TEC FALL 1980 83 Cristóbal Jones. El rumbo que llevan es una isla del... de mimos que vienen a divertirnos. Dentro del ambiente farandulero unos se convierten en músicos y otros en actores que nos cuentan una historia. Luego se desarrolla la tragicomedia de tantos caudillos derrocados en tantos países latinoamericanos y...

  10. AREA DEL PERSONALE SETTORE PERSONALE DOCENTE E RICERCATORE

    E-print Network

    Milano-Bicocca, Università

    AREA DEL PERSONALE SETTORE PERSONALE DOCENTE E RICERCATORE UFFICIO GESTIONE CARRIERE Circolare n, infine, che non possono presentare domanda di prolungamento ai sensi del D.Lgs. 503/1992, i professori di

  11. ANNEX A L'INFORME DEL RECTOR DOCUMENT INFORMATIU

    E-print Network

    Casanellas, Marta

    /11. Reunió del Consejo de Universidades 08. Dinar-reunió dels rectors de l'ACUP amb el Molt Hble. Sr. Artur, Secretari d'Universitats i Recerca 27. Dinar cloenda FESTIBITY Convenis i documents signats amb protocol: 14

  12. Progetto di efficientamento energetico del Polo Universitario di Grugliasco

    E-print Network

    Sproston, Jeremy

    Progetto di efficientamento energetico del Polo Universitario di Grugliasco #12;Edifici Polo Polo comune delle aule ­ costruzione anno 2000 Dipartimento Scienze Veterinarie ­ costruzione anno 2000 2014 Grugliasco Consumi metano equivalente #12;Il progetto di efficientamento energetico del Polo

  13. Del 1: Grunnleggende Digital CMOS YNGVAR BERG

    E-print Network

    Sahay, Sundeep

    Del 1: Grunnleggende Digital CMOS YNGVAR BERG I. Innhold TRANSISTOR SOM BRYTER anvendt i enkleMOS transistorer. Pass transistorer og transmisjonsporter. Tristate buffer og tristate inverter. Ulike typer. 2. Transistor som bryter. Kapittel 1.3 side 9. 3. CMOS inverter. Kapittel 1.4.1 side 10. 4. NAND

  14. MANUAL TELESCOPIO MONS OBSERVATORIO DEL TEIDE

    E-print Network

    (Apartado 1.5), situar la escalera al sur del pilar, de modo que la plataforma superior quede frente al cerca de la plataforma (S), de modo que pueda extraerse (o colocarse) la tapa de forma c´omoda. 3. Fijar

  15. LA ORGANIZACIÓN COMO ANTESALA DEL ÉXITO ACADÉMICO

    Microsoft Academic Search

    Ana García Gat

    2009-01-01

    Uno de los problemas más destacados del sistema educativo es el fracaso escolar, el cual se debe a la conjunción de un gran número de variables y circunstancias. Nos debemos preguntar, ¿Saben nuestros alumnos estudiar?, ¿han aprendido técnicas y procedimientos fundamentales para superar con éxito su proceso de enseñanza-aprendizaje?

  16. Facultad de Derecho DATOS DEL ALUMNO

    E-print Network

    Escolano, Francisco

    Facultad de Derecho DATOS DEL ALUMNO APELLIDOS 1º 2º NOMBRE NIF DIRECCIÓN LOCALIDAD CP PROVINCIA EMAIL TFNO. FIJO TFNO. MOVIL IMPORTANTE Para obtener los correspondientes títulos de Derecho y ADE, el elección, con los siguientes requisitos: - Los créditos de libre elección necesarios son 30,5 para Derecho

  17. DEL MORAL, SANDLER & MUERDTER--1 draft version

    E-print Network

    del Moral, Roger

    on the Muddy River Lahar, Mount St. Helens, Washington R. del Moral Jeremy E. Sandler Claire P. Muerdter Abstract We surveyed vegetation 28 summers after the 1980 eruption of Mount St. Helens, Washington spawned intervals = 20 ft (6.09 m). Study conducted between 900 and 1320 m a.s.l. Introduction Mount St. Helens

  18. Introduction to Triumpho del Govierno Popular

    Microsoft Academic Search

    Anne Oravetz Albert

    2004-01-01

    The Triumpho del Govierno Popular, y de la Antiguedad Holandesa by Miguel de Barrios (Daniel Levi de Barrios) describes the political and religious 'government' of the community, and includes accounts of its literary and charitable associations, along with poems, encomia, funeral orations, and other miscellanea from de Barrios' Jewish oeuvre. This excerpt constitutes the opening of the work, part of

  19. Stato di avanzamento del lavoro di tesi

    E-print Network

    Spagnolo, Filippo

    Stato di avanzamento del lavoro di tesi Luca Malagoli Dipartimento di Fisica e Tecnologie Relative in attesa di pubblicazione · Le scuole di storia della fisica, (con C.Romagnino), in uscita su La fisica for the history of Sciences · Premio Nobel per la fisica 2008: un caso paradigmatico per la storia della fisica

  20. UNIVERSIDAD SIMN BOLVAR Informe del proceso de

    E-print Network

    Vásquez, Carlos

    UNIVERSIDAD SIMÓN BOLÍVAR SECRETARÍA Informe del proceso de inscripción de los bachilleres asignados a la USB por el proceso CNU-OPSU 2012 22 de Febrero de 2013 #12;Universidad Simón Bolívar PROF Vicerrector Administrativo PROF. CRISTIÁN PUIG Secretario Elaboración Prof. Cristián Puig Lic. Lucy Pires #12

  1. Escuelas e interpretaciones del pensamiento administrativo

    Microsoft Academic Search

    Francisco Velásquez Vasquez

    2002-01-01

    El artículo siguiente presenta el proceso evolutivo que ha tenido el pensamiento administrativo a lo largo del siglo XX. Se distinguen tres etapas y en cada etapa se identifica una escuela de pensamiento. Esas escuelas son: la escuela Clásica, que tuvo su desarrollo durante el período comprendido entre 1900-1930, en el mundo occidental y en los contextos culturales de los

  2. Quina és la funció del gen clonat?

    Microsoft Academic Search

    Margarita Soriano; Francisca Guerola

    2008-01-01

    Presentem una activitat didàctica complementària per a alumnes de segon de batxillerat. A partir d’una seqüència de nucleòtids del genoma de Paenibacillus barcinonensis determinem la regió codificant d’un gen, la proteïna corresponent i la seva funció. Com a annex s’inclou el guió per a l’alumnat.

  3. LA TEORÍA DEL CAOS EN LA ECONOMÍA

    Microsoft Academic Search

    Fredy H. Wompner G

    2008-01-01

    En el presente trabajo se examinan los conceptos generales al uso sobre el caos. Se catalogan los conceptos clave que pueden ser útiles y que históricamente han conformado una teoría del desorden y su situación actual en diversas publicaciones. Se analiza desde su historia, evolución, principios e implicancias en otras disciplinas como en la economía. En esta dirección se realiza

  4. APUNTES PARA UN ESTUDIO DEL DISEÑO INDUSTRIAL

    Microsoft Academic Search

    Ignacio Casado Galván

    2009-01-01

    La máquina es quizá el factor dominante de nuestra época. Desde la primera mitad del XIX se desarrolla une nuevo sistema de acción sobre la materia y de producción de objetos permitiendo la multiplicación de objetos consecuencia de la producción en serie. El diseño industrial es así la forma característica de la producción de objetos de la sociedad industrial, es

  5. METODI MATEMATICI PRIMA PROVA in ITINERE del 17 novembre 2003

    E-print Network

    Gianazza, Ugo

    convergenza. Soluzione. Risulta z = 0 singolarit`a essenziale, Res(f, 0) = 1 - cos 1 z = 2i polo del primo ordine, Res(f, 2i) = e-i 2 z = -2i polo del primo ordine, Res(f, -2i) = ei 2 z singolarit`a eliminabile = -9 polo del primo ordine, Res(f, -9) = - 2 cos 1 27 z = 9 2 polo del primo ordine, Res(f, 9 2 ) = 2

  6. Departamento de Ciencias del Mar y Biologa Aplicada Vdeo promocin estudios en Ciencias del Mar

    E-print Network

    Escolano, Francisco

    : "Desarrollo de capacidades para la gestión de la pesca sostenible en el suroeste del Océano Índico para preparar una nueva generación de profesionales cualificados en la gestión sostenible de la pesca

  7. LA ENSEANZA EN INFORMACIN EN LA SOCIEDAD DEL CONOCIMIENTO : EL CASO DEL SISTEMA AGRCOLA EN FRANCIA

    E-print Network

    Paris-Sud XI, Université de

    LA ENSE�ANZA EN INFORMACI�N EN LA SOCIEDAD DEL CONOCIMIENTO : EL CASO DEL SISTEMA AGRÍCOLA EN y el uso de informaciones apoyándose en tecnologías de la información y de la comunicación. El conocimiento y a su reparto que fundan la dimensión societal y que erigen la educación y los sistemas escolares

  8. Gulliver dormido de Samuel Rovinski: Una parodia del discurso del poder

    E-print Network

    Rojas, Mario A.

    1990-10-01

    espaciales y actuando de acuerdo a las condiciones de un acto de habla plenamente acabado (o incumplido por trasgresiones a los postulados básicos de la comunicación). Además siguen reglas de conducta similares y los mismos actos ilocutivos del habla...), en el deber ineludible de explorar y señalar la verdad de los acontecimientos sociales, en la misión de un teatro que eduque mientras entretiene y que sabe despertar el espíritu crítico del público, me siento comprometido por mis FALL 1990...

  9. COMPORTAMENT DEL PAS DEL CAMPUS DE LA UIB, EN REFERNCIA A LA MOBILITAT

    E-print Network

    Oro, Daniel

    PARTICIPACIÓ VA SER MOLT ELEVADA 2. LA MILLORA DE LA CARRETERA, L'AVARIA DEL METRO EL CURS 2007-2008 I L; 39,9% Bus, Metro; 24; 16,8% Bus, Metro, Tren; 1; 0,7% Metro; 36; 25,2% Metro, Tren; 21; 14,7% Taxi, Metro, Bus; 1; 0,7% Taxi, Tren, Metro, Bus; 1; 0,7% Tren; 2; 1,4% ·Veient l'absurd dels resultats s

  10. ACCORDO QUADRO DI COLLABORAZIONE CORPO NAZIONALE DEI VIGILI DEL FUOCO

    E-print Network

    Robbiano, Lorenzo

    ACCORDO QUADRO DI COLLABORAZIONE TRA CORPO NAZIONALE DEI VIGILI DEL FUOCO E UNIVERSITA' DEGLI STUDI DI GENOVA Il Corpo Nazionale dei Vigili del Fuoco (di seguito denominato Corpo Nazionale), C.F. n. 80219290584, rappresentato dal Direttore regionale dei vigili del fuoco della Liguria, Ing. Renato Riggio

  11. Evoluzione del mercato dei prodotti e servizi forestali e

    E-print Network

    Pettenella, Davide

    1 Evoluzione del mercato dei prodotti e servizi forestali e relativi problemi di governance Davide? Quadro congiunturale e cambiamenti strutturali del mercato del legname La crisi dei sub-prime in USA #12 in Russia e regioni limitrofe (Fonte: Jarno Seppala, PÖYRY, 2006) Distribuzione dei prelievi per tipo di

  12. DERECHOS DEL EMPLEADO LEy PARA LA PROtECCin

    E-print Network

    Rock, Chris

    DERECHOS DEL EMPLEADO LEy PARA LA PROtECCión DEL EMPLEADO COntRA LA PRuEbA DEL POLígRAfO PROHIBICIONES ExENCIONES DERECHOS DE LOS ExAMINADOS CUMPLIMIENTO Generalmente se le prohíbe al empleador que le aspirante a un trabajo por haberse negado a someterse a la prueba o por haberse acogido a otros derechos

  13. Realidades de la independencia del Banco de la República

    Microsoft Academic Search

    Salomón Kalmanovitz

    1997-01-01

    La autonomía del banco central colombiano es parte del proceso político que busca reducir el exagerado centralismo colombiano. Sin embargo, el poder central no fue limitado en grado suficiente por la Constitución de 1991, como demuestra el hecho de que el Ministro de Hacienda es el Presidente de la Junta Directiva del Banco de la República. Esto no sucede en

  14. 33 CFR 80.1118 - Marina Del Rey, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...1 2010-07-01 2010-07-01 false Marina Del Rey, CA. 80.1118 Section 80.1118 Navigation and Navigable Waters...DEMARCATION LINES Pacific Coast § 80.1118 Marina Del Rey, CA. (a) A line drawn from Marina Del Rey Breakwater South...

  15. Lorica, una colonia árabe a orillas del río Sinú

    Microsoft Academic Search

    Joaquín Viloria De La Hoz

    2003-01-01

    En este artículo se estudian las circunstancias como llegaron los primeros inmigrantes árabes a Colombia desde finales del siglo XIX, así como sus actividades económicas más importantes. La investigación escogió a Lorica como punto de referencia, al ser una de las poblaciones más próspera de la subregión del Sinú durante el siglo XIX y primeras décadas del siguiente, en donde

  16. On the Approximations of Multiple target filtering P. Del Moral

    E-print Network

    Del Moral , Pierre

    On the Approximations of Multiple target filtering equations P. Del Moral Centre INRIA de Bordeaux (2010). To appear in Stochastic Analysis and Applications (2011). P. Del Moral (INRIA) INRIA Bordeaux Approximation models P. Del Moral (INRIA) INRIA Bordeaux-Sud Ouest 2 / 25 #12;Some notation : E measurable space

  17. On the Approximations of Multiple target filtering P. Del Moral

    E-print Network

    Del Moral , Pierre

    On the Approximations of Multiple target filtering equations P. Del Moral Centre INRIA Bordeaux (2010). To appear in Stochastic Analysis and Applications (2011). Del Moral (INRIA) INRIA Centre models 7 Approximation models Del Moral (INRIA) INRIA Centre Bordeaux-Sud Ouest, France 2 / 25 #12;Some

  18. Particle methods in stochastic engineering P. Del Moral

    E-print Network

    Del Moral , Pierre

    Particle methods in stochastic engineering P. Del Moral Centre INRIA Bordeaux-Sud Ouest 10th, Doucet. Fluctuations of Interacting Markov Chain Monte Carlo Models (2008) + Ref.. P. Del Moral (INRIA mechanics, financial math, biology, chemistry, rare event, optics, hybrid systems,... P. Del Moral (INRIA

  19. COMUNICATO STAMPA Nuove frontiere del Corso di Laurea in Fisioterapia

    E-print Network

    Costagliola, Gennaro

    COMUNICATO STAMPA Nuove frontiere del Corso di Laurea in Fisioterapia SALERNO, 30 maggio 2014 "Ricerca, didattica e formazione: nuove frontiere del Corso di Laurea in Fisioterapia" Campus di Baronissi in Fisioterapia intende promuovere un'ulteriore analisi della formazione universitaria del Fisioterapista

  20. 33 CFR 80.1118 - Marina Del Rey, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...1 2011-07-01 2011-07-01 false Marina Del Rey, CA. 80.1118 Section 80.1118 Navigation and Navigable Waters...DEMARCATION LINES Pacific Coast § 80.1118 Marina Del Rey, CA. (a) A line drawn from Marina Del Rey Breakwater South...

  1. El Colegio Mayor del Rosario y la reforma universitaria Santanderista

    Microsoft Academic Search

    Luis Eduardo Fajardo; Carlos Cañon; Juanita Villaveces; Diego HERRERA

    2002-01-01

    Este trabajo presenta evidencia del impacto financiero y administrativo de la reforma educativa de Santander en una universidad privada de comienzos del siglo XIX en Colombia. La reforma educativa emprendida por el gobierno colombiano durante las dácadas de 1820 y 1830fue un ambicioso proyecto de modernización que era visto como una parte importante del proceso de rompimiento con el pasado

  2. Factores Reproductivos Asociados al Riesgo de Cncer del Seno

    E-print Network

    Danforth, Bryan Nicholas

    funcionamiento normal del seno como al riesgo de cáncer del seno. Se sabe que estar en edad avanzada al momento edad temprana es un factor protector. · Mientras más joven sea la mujer al momento de tener su primer hijo, menor es su riesgo de desarrollar cáncer del seno más tarde en la vida. · El riesgo de

  3. Hispanic and European Studies Program Ttulo del curso

    E-print Network

    Geffner, Hector

    Hispanic and European Studies Program Título del curso: Lengua de instrucción Profesora: Meritxell recomendados créditos Pre-requisitos del curso: Pre-requisitos de lengua universitario o equivalente. Enfoque general y disciplinar del curso: trata sobre la ciudad de Barcelona desde una perspectiva histórica

  4. Una breve gua para padres acerca del autismo: Informacin para

    E-print Network

    Sarkar, Nilanjan

    Tennessee y que recientemente haya recibido un diagnóstico de trastorno del espectro autista (ASD por sus o trastorno generalizado del desarrollo-no especificado (PDD-NOS por sus siglas en inglés). Incluso si usted ha estado sospechando un trastorno del espectro autista, recibir el diagnóstico puede

  5. Allyn Young y el desarrollo de la teoría del crecimiento

    Microsoft Academic Search

    Lauchlin Currie; Traducción de Álvaro Montenegro

    1993-01-01

    Con este artículo el autor busca rendir un tardío homenaje a quien fuera su maestro, Allyn Young. La teoría económica del crecimiento presenta, a juicio del autor, dos contribuciones fundamentales: la de Adam Smith, para quien la productividad nace de la profundización de la división del trabajo; y la de Allyn Young, quien retoma el análisis de Smith para explicar

  6. DISCURS DEL RECTOR DE LA UPF, JOSEP JOAN MORESO,

    E-print Network

    Geffner, Hector

    DISCURS DEL RECTOR DE LA UPF, JOSEP JOAN MORESO, AMB MOTIU DE LA INAUGURACI� DEL CURS 2007-2008 Sra. Blanca Palmada, comissionada per a Universitats i Recerca, Sra. Montserrat Ballarín, regidora d'Educació de l'Ajuntament de Barcelona, Sra. Mercè Sala, presidenta del Consell Social de la UPF, Sra. Amparo

  7. Pseudnimo: Bardo Thdol Viaje al "Techo del mundo"

    E-print Network

    Geffner, Hector

    Pseudónimo: Bardo Thödol Viaje al "Techo del mundo" #12;Entre címbalos, tambores y bailes chino,150 kilómetros de longitud y cruza montañas superiores a los 5000 metros por sobre el nivel del mar. El tiempo del primer recorrido fue de 13 horas y 26 minutos. No faltará mucho para que las agencias de viajes

  8. Albert Hirschman en Colombia y la planeación del desarrollo

    Microsoft Academic Search

    Caballero Argáez Carlos

    2009-01-01

    Este ensayo se refiere a los ejercicios de diagnóstico y formulación de estrategias de inversión pública en Colombia en los años cincuenta del siglo XX. Se hace un recuento de los antecedentes del Informe del Consejo Nacional de Planificación correspondiente al año de 1952, que contó con la asesoría de Albert Hirschman (quien residió en Colombia entre 1952 y 1956)

  9. Disposizione N. 4573/2014 del 20/11/2014

    E-print Network

    Guidoni, Leonardo

    orientamento Programma Marco Polo Il direttore VISTA: la L.168/1989 VISTO: il D.L.vo n.165 del 2001 e programma Marco Polo per l'anno accademico 2015-2016 Sapienza Università di Roma Area per l' del progetto Obiettivo del programma Marco Polo facilitare l'iscrizione di studenti cinesi ai corsi di

  10. Epgrafe, Revista del Depto. de Matemticas y Fsica de la UAA Modelacin matemtica del control de plagas en un cultivo

    E-print Network

    Vela-Arevalo, Luz V.

    plagas, control discontinuo, impulsos. 1. Introducción Los modelos matemáticos y en particular, losEpígrafe, Revista del Depto. de Matemáticas y Física de la UAA Modelación matemática del control de función de impulsos repetidos infinitos. En el segundo modelo, el efecto del insecticida biológico se

  11. Stigma: il marchio sociale del suicidio In occasione della giornata mondiale per la prevenzione del suicidio, studiosi e

    E-print Network

    Di Pillo, Gianni

    Stigma: il marchio sociale del suicidio In occasione della giornata mondiale per la prevenzione del Stigma: un grande ostacolo per la prevenzione del suicidio. All'evento - promosso dall salute mentale. Lo stigma rappresenta il marchio negativo associato a coloro che hanno tentato il

  12. El tiempo es dinero: Cálculo del valor social del tiempo en Lima Metropolitana para usuarios de transporte urbano

    Microsoft Academic Search

    Denisse Calmet; Juan Miguel Capurro

    2011-01-01

    El objetivo de este trabajo es estimar el valor social del tiempo (VST) de los usuarios de transporte urbano en Lima Metropolitana. Con dicho fin, se presentan dos estimaciones del VST. En el primer caso, se utiliza información de la Encuesta Nacional de Hogares para aproximar el VST a partir del ingreso bruto mensual. En el segundo caso, utilizando información

  13. NECESIDADES DE FORMACIÓN DEL DOCENTE UNIVERSITARIO DEL CARIBE COLOMBIANO DE CIENCIAS ADMINISTRATIVAS ECONÓMICAS Y CONTABLES, DESDE LA COMPLEJIDAD

    Microsoft Academic Search

    Jose Enrique Rojas Chadid

    2010-01-01

    El escrito se propone mostrar las principales necesidades de formación del docente universitario del Caribe colombiano de ciencias administrativas económicas y contables, desde la complejidad, ya que la formación del docente universitario en la actualidad incluye en muy poca medida las ciencias de la complejidad lo que trae como consecuencia el refuerzo de una formación que privilegia el pensamiento lineal

  14. Ciclo de vida del VIH Enlace y fusin: El VIH empieza su ciclo de vida

    E-print Network

    Levin, Judith G.

    inversa convierte la cadena simple del ARN vírico en cadena doble de ADN vírico. Integración: El nuevo ADN integrasa "esconde" el ADN vírico dentro del propio ADN de la célula anfitriona. El ADN del VIH integrado se­800­448­0440. En Internet www.aidsinfo.nih.gov/infoSIDA. mayo del 2005 1 Human DNA HIV DNA ARN del VIH ADN del VIH

  15. El proyecto reformador del General José Ballivián. La construcción del Estado-Nación durante el gobierno provisional de 1841-1843

    Microsoft Academic Search

    Jordi Aizcorbe Sagrera

    2010-01-01

    Durante los dos primeros años del gobierno de José Ballivián (1841- 1847) se aprueba una numerosa legislación respecto a la Instrucción Pública, la reforma del ejército, la ocupación del territorio nacional y la reforma de la administración pública del estado. A raíz de esta legislación se establecen bases para el avance en la construcción del estado-nación boliviano mediante el control

  16. Consejo Asesor Consejo Asesor del Decanato de Estudios Tecnolgicos Acta 03-2013 del 05/04/13 Pg. 1 de 6

    E-print Network

    Vásquez, Carlos

    Consejo Asesor Consejo Asesor del Decanato de Estudios Tecnológicos Acta 03-2013 del 05/04/13 Pág Asesor del Decanato de Estudios Tecnológicos, presidido por el ciudadano Decano, Prof. Armando Jiménez Mejor Estudiante 7. Casos de estudiantes. 8. Varios 1. Consideración del Orden del Día Sometido

  17. Consejo Asesor Consejo Asesor del Decanato de Estudios Tecnolgicos Acta 04-2013 del 06/05/13 Pg. 1 de 5

    E-print Network

    Vásquez, Carlos

    anteriores 3. Informe del Decano 4. Indicadores de Gestión del Decanato de Estudios Tecnológicos 5. Casos deConsejo Asesor Consejo Asesor del Decanato de Estudios Tecnológicos Acta 04-2013 del 06/05/13 Pág Asesor del Decanato de Estudios Tecnológicos, presidido por el ciudadano Decano, Prof. Armando Jiménez

  18. Clinical and Laboratory Update on the DEL Variant.

    PubMed

    Nuchnoi, Pornlada; Thongbus, Jairak; Srisarin, Apapan; Kerdpin, Usanee; Prachayasittikul, Virapong

    2014-01-01

    Serological assays for the RhD blood group are based on detection of the RhD antigen on human red blood cells using a specific anti-D antibody. The weak expression of the RhD antigen in the DEL variant hinders the sensitivity of conventional serological assays. Evidence of anti-D immunization in patients with D-negativity who have received DEL-variant blood units has been reported in various populations. This observation has prompted the need for genetic epidemiological and clinical data on the DEL variant in the development of DEL molecular diagnostic testing. This review highlights the molecular features of the DEL variant, the clinical consequences of DEL-blood transfusion, and current approaches for detection of the DEL-variant for donor screening and transfusion. PMID:25316658

  19. Del Norte means north to recycling

    SciTech Connect

    Aquino, J.T.

    1998-06-01

    Del Norte Regional Recycling and Transfer Station is owned by the city of Oxnard, California and operated by BLT Enterprises, Inc. The Del Norte facility--located in southwestern Ventura County about an hour northwest of Los Angeles--processes polyethylene terephthalate (PET) and high-density polyethylene (HDPE) plastic containers, aluminum, steel, glass, old corrugated containers (OCC), newspapers, computer printout paper, white and colored ledger paper, coated book, supermix paper, telephone books, and old magazines. According to the company, there has been virtually no community opposition to the site. The facility has few neighbors, and those are agricultural. To keep the community relationship strong, the facility`s design and location all but eliminated odor and noise complaints. The building was designed against the prevailing wind pattern, and BLT processes odorous material fast. A misting system installed for dust suppression also can be used with a solution for odor control should the need arise.

  20. II Congreso del Autor Dramático Iberoamericano

    E-print Network

    Unruh, Vicky

    1998-04-01

    two days of the Congress, June 26-27, and back in San Juan, Puerto Rican playwrights Carlos Canales, Aleyda Morales (President of Puerto Rico's Círculo Nacional de Autores Dramáticos), and José Luis Ramos Escobar spoke on the recent directions... en dos actos, under the direction of Jaime Velasco and with performances by José Ramón Segurajáuregui and Sergio Navarro. On June 26, Aleyda Morales staged her monologue Enigma de una mujer, performed by Ana Pino. The II Congreso del Autor...

  1. Premio Ollantay 1989 - Acta del jurado

    E-print Network

    1990-04-01

    20 LATIN AMERICAN THEATRE REVIEW Premios Ollantay 1989 - Acta del jurado Desde 1977 el Centro Latinoamericano de Creación e Investigación Teatral (CELCIT) otorga anualmente el Premio Latinoamericano "Ollantay," en reconocimiento a grupos... María Teresa Castillo, Luis Molina López, Juan Carlos Gene, Orlando Rodríguez B. y Luis Masci, reunido en Caracas el 30 de noviembre de 1989, acordó por unanimidad otorgar los siguientes galardones: 1. Hombre o Mujer de Teatro a Patricia Ariza, de...

  2. La evolucion del modernismo en Puerto Rico

    E-print Network

    Gonzalez-Hernandez, Miriam Mercedes

    1989-01-01

    en que dio impulso a las letras puertorriquenas y ademas, sus poetas defendieron el idioma en el momento historico- politico mas significativo que haya vivido la isla de Puerto Rico. DEDICATORIA Dedico esta tesis a mis hijos Jorge y Cristina, a... EVOLUCION DEL MODERNISMO. 23 Auge. Revista de las Antillas. 23 24 Poetas que mas influenciaron en el modernismo puertorriqueno. . . . . . . . . . IV MODERNISTAS INSULARES. 27 30 Poetas representativos. 30 CAPITULO pagina Virgilio Davila. Luis...

  3. Degenerations of del Pezzo surfaces I

    Microsoft Academic Search

    Paul Hacking; Yuri Prokhorov

    2005-01-01

    Let X be a surface with quotient singularities which admits a smoothing to the plane. We prove that X is a deformation of a weighted projective plane P(a^2,b^2,c^2), where a,b,c is a solution of the Markov equation a^2+b^2+c^2=3abc. We also prove a generalisation for del Pezzo surfaces of degree K^2 at least 5.

  4. El uso de la neuromodulación para el tratamiento del temblor

    PubMed Central

    Bendersky, Damián; Ajler, Pablo; Yampolsky, Claudio

    2014-01-01

    Introducción: El temblor puede ser un desorden incapacitante y el tratamiento de primera línea para estos pacientes es farmacológico. Sin embargo, este tratamiento puede llevar a una reducción satisfactoria del temblor en sólo el 50% de los pacientes con temblor esencial. La talamotomía era el tratamiento de elección para el temblor refractario al tratamiento médico hasta que comenzó a utilizarse la estimulación cerebral profunda (ECP) del núcleo ventral intermedio (Vim) del tálamo. En la actualidad, raramente se realiza la talamotomía. Métodos: Este artículo es una revisión no sistemática de las indicaciones, resultados, parámetros de programación y técnica quirúrgica de la ECP del Vim para el tratamiento del temblor. Resultados: Aunque los resultados clínicos son similares usando la talamotomía o la ECP del Vim, la primera causa más efectos adversos que la última. Además, la ECP puede ser usada bilateralmente, mientras que la talamotomía tiene un alto riesgo de causar disartria cuando se realiza de ambos lados. La ECP del Vim logró una adecuada mejoría del temblor en varias series de pacientes con temblor causado por temblor esencial, enfermedad de Parkinson o esclerosis múltiple. Además del Vim, hay otros blancos que están siendo usados por varios autores, tales como la zona incerta y las radiaciones prelemniscales. Conclusión: La ECP del Vim es un tratamiento útil para el temblor incapacitante refractario al tratamiento médico. Es esencial realizar una precisa selección de pacientes, así como utilizar una técnica quirúrgica correcta. Aún se desconoce el mejor blanco estereotáctico para el temblor, aunque el Vim es el más usado. PMID:25165613

  5. Morphology, geology and geochemistry of the "Salar del Gran Bajo del Gualicho" (Rio Negro, Argentina)

    USGS Publications Warehouse

    Angelucci, A.; Barbieri, M.; Brodtkorb, A.; Ciccacci, S.; Civitelli, G.; De Barrio, R.; Di, Filippo M.; Fredi, P.; Friedman, I.; Lombardi, S.; Schalamuk, A.I.; Toro, B.

    1996-01-01

    A multidisciplinary study of the Gran Bajo del Gualicho area (Rio Negro - Argentina) was carried out; the aim was to delineate its geological and geomorphological evolution and to estabilish the genesis of salts filling the depression. Climatic conditions were analized first to individuate their role in the present morphogenetic processes; moreover the main morphological features of present landscape were examined as well as the stratigraphy of the outcropping formations, and of the Gran Bajo del Gualicho Formation in particular. Finally, a possible geomorphological evolution of the studied area was traced. Geophysical analyses allowed to estabilish that the paleosurface shaped on the crystalline basement is strongly uneven and shows evidence of the strong tectonic phases it underwent. The result of isotope analyses confirmed that the salt deposits on the Gran Bajo del Gualicho bottom were produced by fresh water evaporation, while strontium isotope ratio suggested that such waters were responsible for solubilization of more ancient evaporitic deposits.

  6. Estudio teórico del CO2. Orbitales de valencia y del ``core''

    NASA Astrophysics Data System (ADS)

    Olalla Gutiérrez, E.

    Hemos calculado las intensidades de las transiciones E1 a los miembros de las series de Rydberg con origen en los orbitales ``no enlazantes'' del dióxido de carbono, especie de conocida relevancia atmosférica. Se han computado, asimismo, los continuos de fotoionización correspondientes a los distintos canales de ionización, representándolos como densidad espectral de fuerza de oscilador frente a la energía del fotón incidente; mostramos los resultados df/dE para la fotoionización total de esta especie en el intervalo 15-60 eV. Todos los cálculos se han llevado a cabo mediante la formulación Molecular del Método de los Orbitales de Defecto Cuántico, MQDO [1,2]. La calidad de los resultados que presentamos se ha evaluado en base a la comparación con los datos, tanto experimentales como teóricos, disponibles en la bibliografía. El acuerdo encontrado es altamente satisfactorio

  7. Simulation particulaire d'evenements rares P. Del Moral

    E-print Network

    Del Moral , Pierre

    Simulation particulaire d'´ev´enements rares P. Del Moral Centre INRIA de Bordeaux - Sud Ouest GT Projet AST&Risk Univ. Lyon, d´ecembre 2008 P. Del Moral (INRIA) INRIA Bordeaux-Sud Ouest 1 / 31 #12 des Cte de normalisation 4 Quelques r´ef´erences P. Del Moral (INRIA) INRIA Bordeaux-Sud Ouest 2 / 31

  8. RELACIÓN MÉDICO PACIENTE: DERECHOS DEL ADULTO MAYOR

    PubMed Central

    Barrantes-Monge, Melba; Rodríguez, Eduardo; Lama, Alexis

    2009-01-01

    Existen prejuicios en relación con la vejez, incluso entre los profesionales que se dedican a la gerontología. Uno común y peligroso es considerar que los viejos son todos enfermos o discapacitados. La relación médico-paciente es la piedra angular de la práctica y ética médicas. Para alcanzar el respeto por los adultos mayores es necesaria una medicina prudente, basada en una práctica en la cual la reflexión ética y clínica pueda contribuir. Esto último es posible si se hacen valer los derechos del adulto mayor, en particular como paciente para la toma de decisiones. PMID:20379380

  9. COMUNICATO STAMPA Tariffe trasporto pubblico: dichiarazione del rettore Tommasetti

    E-print Network

    Costagliola, Gennaro

    COMUNICATO STAMPA Tariffe trasporto pubblico: dichiarazione del rettore Tommasetti Il Magnifico Regione Campania, delle tariffe riguardanti il trasporto pubblico che tanta preoccupazione avevano destato

  10. GENERAL TECHNICAL REPORT PSW-GTR-245 Manejando los Riesgos del Manejo del

    E-print Network

    Standiford, Richard B.

    explícitamente en el proceso de toma de decisiones de los gerentes de incendios daría lugar, con suerte, a un reconocimiento e internalización de estos factores en sus decisiones. Palabras clave: Riesgo profesional, toma de). En esencia, la gestión del riesgo es un problema en la toma de decisiones basada en el riesgo, y el

  11. Universidad Simn Bolvar Programa auror@ para la Gestin delPrograma auror@ para la Gestin del

    E-print Network

    Vásquez, Carlos

    No existe un PGDE que contribuya a agilizar el flujo documental que sustenta los procesos administrativos Institución. #12;Pl t i t d l Pr blPlanteamiento del Problema Procesos administrativos repetitivos y pocop y p de los resultados. Listado de procesos administrativos ap inc

  12. IMPLICACIONES DEL MODELO DE ENSEÑANZA NATURAL DEL LENGUAJE EN LA INTERVENCION DE PERSONAS CON AUTISMO

    Microsoft Academic Search

    Pedro Gortázar

    Equipo CEPRI RESUMEN: El Modelo de Tratamiento Natural del Lenguaje constituye el para- digma de intervención actualmente más válido para hacer frente a los déficits sociales y comunicativos de las personas con autismo. En esta ponencia se discuten las implicaciones de este Modelo de cara a la formu- lación de objetivos curriculares, definición de criterios de respuesta, técnicas de entre-

  13. La aplicación del modelo del estado completo de salud al estudio de la depresión

    Microsoft Academic Search

    Darío Díaz; Amalio Blanco; Javier Horcajo; Carmen Valle

    2007-01-01

    La definición de salud propuesta por la OMS señala que ésta no consiste sólo en la ausencia de enfer- medad, sino también en la presencia de un estado de completo bienestar físico, mental y social. Para concretar en qué consiste este estado positivo, el Modelo del Estado Completo de Salud (MECS) ha definido la salud mental como un conjunto de

  14. GESTIÓN DEL TURISMO DESDE LA PERSPECTIVA DEL BILINGÜISMO Y LA MULTICULTURALIDAD: CASO CIUDAD JUÁREZ

    Microsoft Academic Search

    Tomás J. Cuevas-Contreras; Ercilia Loera Anchondo; Brenda N. Vázquez García

    2010-01-01

    La Organización Mundial del Turismo, (agencia perteneciente a la ONU) refiere que, “el turismo comprende las actividades que realizan las personas durante sus viajes y estancias en lugares distintos a su entorno habitual, por un periodo de tiempo consecutivo inferior a un año, con fines de ocio, por negocios y otros” (OMT, 2006) En base a este concepto y al

  15. Integración del aprendizaje individual y del colaborativo en un sistema hipermedia adaptativo

    Microsoft Academic Search

    Carlos Arteaga; Ramón Fabregat

    2002-01-01

    Resumen— En este artículo se define un Sistema Hipermedia de Aprendizaje Colaborativo Adaptativo (SHACA) en el que se relaciona el Aprendizaje Individual y el Aprendizaje Colaborativo a través de un Modelo Adaptativo. El Modelo Adaptativo permite al Ambiente de Aprendizaje adaptar su comportamiento al estudiante tanto cuando interactúa sólo, como cuando está involucrado en tareas colaborativas. La arquitectura del sistema

  16. Trombosis del seno sagital cerebral: causa infrecuente de cefalea del postparto: a propósito de un caso

    Microsoft Academic Search

    M. Madrazo Delgado; F. J. Redondo Calvo; S. Gil Trujillo; J. L. Castillo; M. Calvo García; G. Bernal García

    2008-01-01

    a Servicio de Radiodiagnóstico. Hospital General de Ciudad Real. Resumen Las trombosis venosas cerebrales del postparto son una entidad muy poco frecuente (3-4 casos por millón). Sus manifestaciones clínicas son variadas, siendo la cefa- lea persistente casi una constante, lo que implica hacer un diagnóstico diferencial con otras causas de cefalea durante el puerperio. Los factores predisponentes reco- nocidos de

  17. Una medición del impacto del Programa de Capacitación Laboral Juvenil PROJoven

    Microsoft Academic Search

    Hugo Ñopo; Miguel Robles; Jaime Saavedra

    2002-01-01

    El presente documento presenta una medición de impacto del programa de capacitación laboral juvenil PROJoven. Se utilizó información socio-laboral de una muestra de beneficiarios y un conjunto de individuos que conformaron el grupo de control. Esta información fue recogida antes de iniciados los cursos de capacitación de la sexta convocatoria (línea de base) y después de seis meses de concluido

  18. Efecto del Programa de Entrenamiento “Manejo del Dolor” en la Documentación de Enfermería en el Expediente Electrónico

    PubMed Central

    Monsiváis, María Guadalupe Moreno; Guzmán, Ma. Guadalupe Interial; Flores, Paz Francisco Sauceda; Arreola, Leticia Vázquez

    2012-01-01

    Resumen En el presente trabajo se muestra la importancia de entrenar al personal de enfermería para mejorar la documentación en el expediente electrónico. Se eligió el manejo del dolor por ser un área prioritaria; una alta proporción de pacientes en período post operatorio cursa con dolor, por lo tanto, la documentación debe ser útil para la toma de decisiones clínicas. Se implementó un programa de entrenamiento denominado “Manejo del Dolor” dirigido al personal de enfermería. Se utilizó la tecnología de la información como herramienta para fortalecer el conocimiento con base en la revisión sistemática de la literatura; el personal de enfermería participante seleccionó la mejor evidencia; posteriormente se trabajó en la transferencia de este conocimiento a la práctica a través del diseño de un protocolo para el manejo del dolor. Se concluye que el conocimiento del manejo del dolor es fundamental para que enfermería documente con mayor precisión sus intervenciones. PMID:24199106

  19. Aprovaci de l'assignaci de complements bsics de recerca del PDI-F (sexennis CNEAI)

    E-print Network

    Yannuzzi Sanchez, Marcelo

    Aprovació de l'assignació de complements bàsics de recerca del PDI-F (sexennis CNEAI) Acord núm.152/2014 del Consell de Govern pel qual s'aprova l'assignació de complements bàsics de recerca del PDI Politècnica de Catalunya, es resol la convocatòria 2013 del complement bàsic de recerca del PDI funcionari

  20. Aprovaci del canvi de pla d'estudis del grau en Recursos energtics i Acord nm. 163/2014 del Consell de Govern pel qual s'aprova el canvi de

    E-print Network

    Yannuzzi Sanchez, Marcelo

    Aprovació del canvi de pla d'estudis del grau en Recursos energètics i miners Acord núm. 163/2014 del Consell de Govern pel qual s'aprova el canvi de pla d'estudis del grau en Recursos energètics i mantenir l'entrada comuna per totes les titulacions, s'ha de modificar el pla d'estudis del Grau en

  1. "La escenificacin del espacio del santo en dos obras de Lope de Vega : Barln y Josaf y El santo negro Rosambuco"

    E-print Network

    Boyer, Edmond

    1 17/02/2010 "La escenificación del espacio del santo en dos obras de Lope de Vega : Barlán y piezas, la inventiva de Lope de Vega resuelve la puesta en teatro del espacio propuesto por la fuente según los episodios, se traduce por técnicas diversas de tratamiento del espacio dramático, y por otra

  2. REVALORIZACIN DEL AMBIENTE Y LOS ESPACIOS LOCALES. TRANSFORMACIONES DEL PODER Y LA AUTORIDAD LOCALES EN LATINOAMRICA BAJO LAS TENSIONES DE LOS PROCESOS DE GLOBALIZACIN

    E-print Network

    Paris-Sud XI, Université de

    REVALORIZACI�N DEL AMBIENTE Y LOS ESPACIOS LOCALES. TRANSFORMACIONES DEL PODER Y LA AUTORIDAD poder en Latinoamérica y la tendencia de revalorización del ambiente y los espacios locales. Se determina en lo importante que las autoridades actúen a través del espacio público de las estructuras

  3. Análisis del Diferencial de Desempleo Andaluz y Extremeño

    Microsoft Academic Search

    Inés P. Murillo Huertas; Fernando Núñez Hernández; Carlos Usabiaga Ibáñez

    2005-01-01

    RESUMEN Andalucía y Extremadura han soportado unas tasas de desempleo sumamente elevadas en las últimas décadas, muy superiores a las del resto de España. Este trabajo pretende exponer posibles explicaciones de este fenómeno. Nuestro período básico de análisis es 1980-2000. En nuestro trabajo realizamos una revisión de las principales variables del mercado de trabajo (incluidas las institucionales): desempleo, población activa,

  4. Los Derechos de los Pacientes del Centro Clnico

    E-print Network

    Los Derechos de los Pacientes del Centro Clínico Los Derechos de los Pacientes del Centro Clínico medir las respuestas de los pacientes al tratamiento. Existen procesos que protegen los derechos de paciente que se observen los derechos fundamentales de la dignidad humana. Esta Declaración de Derechos

  5. Hoja informativa sobre la calidad del aire interior

    E-print Network

    · Moho · Polen · Caspa del pelo de los animales · Humo secundario del tabaco · Formaldehído · Monóxido de deshumidificador para ayudar a controlar el moho. · Limpie para eliminar el polvo y el pelo de los animales. · Arregle las fugas de agua para evitar el moho. · Use spray contra insectos solo cuando sea absolutamente

  6. Paso del Norte Watershed Council Coordinated Water Resources Database Project

    E-print Network

    Brown, Christopher; Sheng, Zhuping; Rich, Matt

    cooperative database project that would provide streamlined access to a range of water resource data in the Paso del Norte region. In August of 2002, the El Paso Water Utilities provided initial funding to the Paso del Norte Watershed Council to develop a...

  7. Conceptos fundamentales del desarrollo de proveedores (Caso de negocios 13)

    Microsoft Academic Search

    Enrique Yacuzzi

    2012-01-01

    El desarrollo de proveedores es una actividad que enriquece la gestión de la cadena de suministro, dotándola de mayor valor a través del aporte mutuo entre empresas clientes y subcontratistas. Este aporte incluye nuevas tecnologías, know-how, herramientas de la calidad y organización del trabajo, además de negociaciones sobre la política de precios, entre otros temas. En este trabajo presentamos sus

  8. EL ESTUDIO DEL PLUMBISMO EN DOANA Y OTROS HUMEDALES ANDALUCES

    E-print Network

    Figuerola, Jordi

    EL ESTUDIO DEL PLUMBISMO EN DOÑANA Y OTROS HUMEDALES ANDALUCES MEMORIA FINAL #12;ii Investigador Científicas (CSIC) para realizar el proyecto "EL ESTUDIO DEL PLUMBISMO EN DOÑANA Y OTROS HUMEDALES ANDALUCES....................................................................................32 3.- Plumbismo en Doñana: la radiografía de aves acuáticas, aves rapaces y sus egagropilas

  9. El marketing del partido político en el gobierno

    Microsoft Academic Search

    Pedro Barrientos Felipa

    2010-01-01

    El marketing político es un campo nuevo para los profesionales del mercadeo y es necesario conocer hasta dónde llega su campo de acción. En tal sentido, el objetivo del artículo es explicar que el marketing es, además de una actividad que puede ser utilizada en procesos electorales, también lo es para momentos en que la organización le corresponde gobernar. Es

  10. Impacto del mercadeo social en organizaciones de servicios

    Microsoft Academic Search

    Carlos Andrés Aristizabal Botero

    2007-01-01

    Este artículo es producto de la investigación “Concepciones del mercadeo social en las grandes organizaciones del sector servicio de la ciudad de Medellín en el año 2006”, la cual buscó describir las concepciones y planteamientos prospectivos establecidos en la gerencia de mercadeo, para el diseño, estructuración e implementación de acciones de Marketing Social. Las metodologías utilizadas fueron cualitativas: entrevistas semiestructuradas,

  11. La efectividad del mercadeo de las PYMES en Boyacá

    Microsoft Academic Search

    Edgar Enrique Zapata Guerrero

    2001-01-01

    El presente artículo es el resultado de una investigación cuantitativa y cualitativa, realizada en Tunja, Duitama y Sogamoso entre 1988 y el 2000, que pretende identificar de qué factores depende la efectividad de mercadeo en las pequeñas y medianas empresas del sector industrial y de servicios en Boyaca. Dicha investigación estableció que la efectividad del mercadeo depende de una mezcla

  12. Informe del Vicerrectorado Administrativo al 08/10/2014

    E-print Network

    Vásquez, Carlos

    parcial y 5 personal Administrativo Ordinarios. Otros El proceso de inclusión de preparadores que Informe del Vicerrectorado Administrativo al 08/10/2014 DIRECCIÓN DE GESTIÓN DEL CAPITAL HUMANO, 3 Administrativos Ordinarios, 2 Obreros Ordinarios y 7 HP Administrativos. Egresos: 15 Académicos

  13. Razonamiento Automatico en Sistemas de Representacion del Conocimiento

    E-print Network

    Alonso, José A.

    Razonamiento Autom´atico en Sistemas de Representaci´on del Conocimiento (y su relaci´on con la utilizaci´on de dichos sistemas para resol- ver problemas cl´asicos de la Inteligencia Artifi- cial. En el herramientas de Razonamiento Autom´atico. Entre los sistemas de representaci´on del cono- cimiento m

  14. Características y tratamiento del trastorno obsesivo resistente al tratamiento

    Microsoft Academic Search

    Daniel Navarro Bayón

    Este artículo presenta el perfil clínico del trastorno obsesivo resistente a las intervenciones terapéuti- cas de primera elección (cognitivo-conductuales y farmacológicas). No existen criterios claros en la definición del concepto de resistencia al tratamiento para los pacientes obsesivos. Para considerar a un paciente como resistente se pueden considerar los siguientes criterios: el paciente ha recibido un mí- nimo de dos

  15. Cdigos UNESCO: 3312 3305 Frecuencia del curso: Anual CEMENTOS ALCALINOS

    E-print Network

    Códigos UNESCO: 3312 3305 Frecuencia del curso: Anual CEMENTOS ALCALINOS Sede del curso: Horas Lectivas: Nº previsto de alumnos: Requisitos de admisión: Entidades que patrocinan el curso: Año en el que se impartió el curso por primera vez: Número de veces que se ha impartido el curso: Inmaculada

  16. CURSOS DE PREPARACI PER A L'OBTENCI DELS

    E-print Network

    Geffner, Hector

    CURSOS DE PREPARACIÓ PER A L'OBTENCIÓ DELS DIPLOMAS DE ESPAÑOL COMO LENGUA EXTRANJERA (DELE) - Versió en català - Versión en castellano - English version #12;CURSOS DE PREPARACIÓ DIPLOMAS DE ESPAÑOL UPF ofereix cursos de preparació per a l'obtenció del Diploma de Español como Lengua Extranjera (DELE

  17. (en transport pblic) Temps total del trajecte: 53 minuts

    E-print Network

    Oro, Daniel

    Inca > UIB (en transport públic) Temps total del trajecte: 53 minuts Inca Tren Estació tren Jacint Verdaguer o Estació Intermodal Metro UIB Comparació transport públic > vehicle privat: Comparació per 1 Emissions addicionals (SO2): 0 kg Transport públicTransport privat Comparació dels viatges acumulats durant

  18. (en transport pblic) Temps total del trajecte: 67 minuts

    E-print Network

    Oro, Daniel

    Muro > UIB (en transport públic) Temps total del trajecte: 67 minuts Muro Tren Estació tren Jacint Verdaguer o Estació Intermodal Metro UIB Comparació transport públic > vehicle privat: Comparació per 1 Emissions addicionals (SO2): 0 kg Transport públicTransport privat Comparació dels viatges acumulats durant

  19. ESTUDIO HIDROQUIMICO DEL ACUFERO DE LA VEGA DE GRANADA

    E-print Network

    Castillo, Antonio

    ESTUDIO HIDROQUIMICO DEL ACUÍFERO DE LA VEGA DE GRANADA CASTILLO, A. (1986) "Estudio hidroquímico del acuífero de la Vega de Granada". Ed. Serv. Publ. Univ. Granada (coedición con Instituto Geológico el título, sobre la hidroquímica (calidad y contaminación) de las aguas de la Vega de Granada. En

  20. Valoración económica de los servicios recreativos del parque ecológico Chipinque

    Microsoft Academic Search

    Guillermo Gándara; Rufino Tamayo

    2006-01-01

    En esta investigación se realiza una estimación del valor económico del beneficio que los visitantes obtienen por disfrutar de los servicios recreativos que ofrece el Parque Chipinque, área natural ubicada en la zona metropolitana de Monterrey, México. Se utiliza el Método de Costo de Viaje estimando una función de demanda por zonas de origen en función de diferentes costos, como

  1. La formación del Partido Conservador: la fusión conservadora

    Microsoft Academic Search

    Fidel Gómez Ochoa

    2003-01-01

    Aunque la Restauración, en cuanto a su historia política, es un período muy agraciado por lo que a atención historiográfica se refiere, todavía algunos aspectos del período están bajo el dominio de lugares comunes discutibles. Uno de ellos es la formación del Partido Conservador. En este artículo se sostiene que la fuerza formada por Antonio Cánovas, si bien hunde sus

  2. Pastoral del Nino: Bringing the Abundant Life to Paraguayan Children

    ERIC Educational Resources Information Center

    Austin, Ann Berghout; Aquino, Cyle; Burro, Elizabeth

    2007-01-01

    Pastoral del Nino is transforming children's lives in rural Paraguay. Part of Pastoral Social (Catholic Social Services), Pastoral del Nino's primary focus is to bring "vida en abundancia" (the abundant life) to families by ensuring that mothers survive childbirth and children reach their first birthdays. In addition, the organization promotes…

  3. ATTIVIT SPORTIVE DEL POLITECNICO 2 Trofeo dei Poli regionali

    E-print Network

    Leonardo, la parigina Eleonore Delattre studentessa Erasmus di Design, Marco Ferrario di Architettura della 36a Course Croisiere Edhec nella rada di Brest. Ecco i partecipanti, tutti del Politecnico: Marco Lecco fra la rappresentativa del Polo di Como (in blu) e Leonardo, poi vincitore con i `Biggols'. Altre

  4. Los hijos del terremoto: Imágenes de un recuerdo

    E-print Network

    Dauster, Frank

    1988-10-01

    pidiéndole explicaciones a Jehová" (157-8). Salvando las distancias, ésta es la familia de Hijos del terre moto, como el tío Juan de la obra tiene marcadas semejanzas con el tío Juan del autor que fue a morir a la guerra civil de España "porque había...

  5. Nro. 12/2009 Acta de la reunin del Consejo Extraordinario de Coordinadores

    E-print Network

    Vásquez, Carlos

    Jubilaciones del personal académico. Se notificó que el ex-vicerrector administrativo de la USB, Prof. Ferrer cual se manejó el proceso de solicitud y entrega del presupuesto por parte del Gobierno Nacional. 9. Se

  6. BOLETN OFICIAL DEL ESTADO Nm. 289 Jueves 1 de diciembre de 2011 Sec. III. Pg. 127986

    E-print Network

    Fitze, Patrick

    , dentro del Eje 3 «Aumento y mejora del Capital Humano», Tema Prioritario 74 «Desarrollar el potencial Humano en el ámbito de la Investigación y la Innovación». La tasa de cofinanciación del FSE es de un 80

  7. Illuminating water and life: Emilio Del Giudice.

    PubMed

    Ho, Mae-Wan

    2015-06-01

    The quantum electrodynamics theory of water put forward by Del Giudice and colleagues provides a useful foundation for a new science of water for life. The interaction of light with liquid water generates quantum coherent domains in which the water molecules oscillate between the ground state and an excited state close to the ionizing potential of water. This produces a plasma of almost free electrons favoring redox reactions, the basis of energy metabolism in living organisms. Coherent domains stabilized by surfaces, such as membranes and macromolecules, provide the excited interfacial water that enables photosynthesis to take place, on which most of life on Earth depends. Excited water is the source of superconducting protons for rapid intercommunication within the body. Coherent domains can also trap electromagnetic frequencies from the environment to orchestrate and activate specific biochemical reactions through resonance, a mechanism for the most precise regulation of gene function. PMID:26098522

  8. [Strengths and future of the Revista Médica del Instituto Mexicano del Seguro Social].

    PubMed

    Fajardo-Dolci, Germán

    2014-01-01

    The journals of medicine arose as a communication tool more than 200 years ago. At the beginning, their nature was local; later, their aim was to spread medical information along the nation; and, finally, they sought to reach the world distribution. The Revista Médica del Instituto Mexicano del Seguro Social was published for the first time 52 years ago, and it has walked its way from local to international distribution. This journal has 23 000 subscribers, it is included in Medline and it reached a 0.112 SCImago Journal Rank in 2012. Its website receives around 200 000 visits monthly and 45 % are foreign visits. In the future, the peer review system is going to be strengthened, and the journal is going to offer audio, video, and applications to reinforce interactive participation between authors, readers in order to reach modernity and draw young new attention. PMID:24758842

  9. Ttulo del Trabajo: Acerca del estilo de pensamiento en los inicios de la Historia de la Ciencia en la Argentina

    E-print Network

    Paris-Sud XI, Université de

    1 Título del Trabajo: Acerca del estilo de pensamiento en los inicios de la Historia de la Ciencia Nacional de Río Cuarto. Facultad de Ciencias Humanas y Facultad de Ciencias Exactas, Físico ­ Químicas y Naturales. Introducción: Una mirada a las actas de las Jornadas de Historias de la Ciencia Argentina (2003

  10. Llamado a cubrir Beca de investigacin. Uso del agua en Sistemas de Produccin Agrcola del Chaco Semirido.

    E-print Network

    Nacional de San Luis, Universidad

    agua en sistemas de producción agrícola en el Chaco Semiárido mediante modelos funcionales de cultivoLlamado a cubrir Beca de investigación. Uso del agua en Sistemas de Producción Agrícola del Chaco iniciar su carrera enfatizando una aproximación sistémica asistida por el uso de modelos matemáticos. L

  11. EL ABOGADO DEL NIÑO COMO GARANTE DEL PLENO EJERCICIO DE LOS DERECHOS DE LOS MENORES DE EDAD

    Microsoft Academic Search

    Lisbeth Rodríguez Martín; Yanelys Palmero Martín

    2012-01-01

    El tratamiento de la niñez y sus derechos resulta tema de interés universal para las ciencias jurídicas modernas, debido a las nuevas tendencias de protección surgidas a partir de la celebración de los Congresos Panamericanos del Niño y la Convención sobre los Derechos del Niño. De modo, que para las ciencias jurídicas cubanas se hace de suma importancia el estudio

  12. La intervención estatal en el mercado del suelo urbano. La reconstrucción del eje cafetero: El caso de Armenia

    Microsoft Academic Search

    Santiago Alberto Camargo; Samuel Jaramillo González

    2011-01-01

    A raíz del pavoroso terremoto que tuvo lugar en el Eje Cafetero colombiano en 1999, que causó grandes pérdidas humanas y una gran destrucción, sobre todo del stock inmobiliario, hubo un gran esfuerzo nacional de solidaridad tanto estatal como privado para socorrer las víctimas. El principal rubro fueron recursos en la forma de subsidios a los afectados para que compraran

  13. Modi rari di annichilazione del sistema protone-antiprotone e struttura elettromagnetica del nucleone

    Microsoft Academic Search

    Marcello Conversi

    1965-01-01

    \\u000a Sunto  Quando un antiprotone annichila con un protone per lo più si originano dei mesoni ? (pioni) ok. In conseguenza del fatto, però, che il nucleone (e l’antinucleone) hanno una loro struttura elettromagnetica, sono possibili\\u000a annichilazioni — peraltro oltremodo rare — in coppie di leptoni (e+ e?; ?+ ??;...). Lo studio di questi processi rari permette di estendere ad una regione

  14. Aprovaci de la proposta d'assignaci de complements addicionals de docncia del PDI

    E-print Network

    Yannuzzi Sanchez, Marcelo

    Aprovació de la proposta d'assignació de complements addicionals de docència del PDI (Convocatòria complements addicionals de docència del PDI (convocatòria 2013) · Document proposta informat favorablement per

  15. Talleres del primer cuatrimestre. Curso 2013-2014 LAS TARDES DE CINE. CINE EN VERSIN ORIGINAL EN EL MACA

    E-print Network

    Escolano, Francisco

    Talleres del primer cuatrimestre. Curso 2013-2014 1 LAS TARDES DE CINE. CINE EN VERSIÓN ORIGINAL EN: 88 min. #12;Talleres del primer cuatrimestre. Curso 2013-2014 2 12 de diciembre Un pez llamado Wanda MÍNIMA DEL 80% DEL TOTAL DE HORAS DEL CURSO *ESTAR AL CORRIENTE CON EL PAGO DEL CURSO *SUPERAR PRUEBA DE

  16. Miami: Meca del exilio cubano y escenario medido aunque efervescente

    E-print Network

    Rizk, Beatriz J.

    2000-10-01

    padre la que parece haber sufrido más en este proceso. Por otra parte, el tema del incesto, que en el caso de los Menéndez fue perpretado tanto por parte del padre como de la madre, convirtiéndose en la comidilla favorita de los medios de comunicación... sensacionalistas durante el juicio que se les siguió, es otra instancia que liga la obra a más de un antecedente dentro de la dramaturgia cubana como a la propia del autor. Ese incesto que se adivina en Electra Garrigó y se insinúa en Lila, la mariposa, y que...

  17. Carrier frequency of GJB2 gene mutations c.35delG, c.235delC and c.167delT among the populations of Eurasia.

    PubMed

    Dzhemileva, Lilya U; Barashkov, Nikolay A; Posukh, Olga L; Khusainova, Rita I; Akhmetova, Vita L; Kutuev, Ildus A; Gilyazova, Irina R; Tadinova, Vera N; Fedorova, Sardana A; Khidiyatova, Irina M; Lobov, Simeon L; Khusnutdinova, Elza K

    2010-11-01

    Hearing impairment is one of the most common disorders of sensorineural function and the incidence of profound prelingual deafness is about 1 per 1000 at birth. GJB2 gene mutations make the largest contribution to hereditary hearing impairment. The spectrum and prevalence of some GJB2 mutations are known to be dependent on the ethnic origin of the population. This study presents data on the carrier frequencies of major GJB2 mutations, c.35delG, c.167delT and c.235delC, among 2308 healthy persons from 18 various populations of Eurasia: Russians, Bashkirs, Tatars, Chuvashes, Udmurts, Komi-Permyaks and Mordvins (Volga-Ural region of Russia); Belarusians and Ukrainians (East Europe); Abkhazians, Avars, Cherkessians and Ingushes (Caucasus); Kazakhs, Uighurs and Uzbeks (Central Asia); and Yakuts and Altaians (Siberia). The data on c.35delG and c.235delC mutation prevalence in the studied ethnic groups can be used to investigate the prospective founder effect in the origin and prevalence of these mutations in Eurasia and consequently in populations around the world. PMID:20739944

  18. PROGRAMMA DEL CORSO "Teoria dei Modelli" DOCENTE: Alessandro Berarducci

    E-print Network

    Berarducci, Alessandro

    PROGRAMMA DEL CORSO "Teoria dei Modelli" DOCENTE: Alessandro Berarducci Anno di corso: 2009 CONTENUTI DELL'INSEGNAMENTO: Introduzione alle nozioni fondamentali della teoria dei modelli con. Eliminazione dei quantificatori. Isomorfismi parziali. Teorie -assiomatizzabili, teorie -assiomatizzabili

  19. Administracin Nacional de Aeronutica y del Espacio DatosdelaNASA

    E-print Network

    en herramientas para que los controladores del tráfico aéreo realicen aproximacio- nes y descensos partidas y métodos para mejorar la coordinación de operacio- nes en tierra y en pista. También se estudian

  20. Breve panorama del teatro en Ecuador durante los años 80

    E-print Network

    Almeida Naveda, Eduardo

    1992-04-01

    SPRING 1992 87 Breve panorama del teatro en Ecuador durante los años 80 Eduardo Almeida Naveda Las condiciones socio-económicas y la ausencia de políticas culturales firmemente estructuradas en el país no han permitido una permanente actividad...