Science.gov

Sample records for adjustable speed ac

  1. Adjustable Speed Drive Part-Load Efficiency - Motor Tip Sheet #11

    SciTech Connect

    2008-07-01

    An adjustable speed drive (ASD) is a device that controls the rotational speed of motor-driven equipment. Variable frequency drives (VFDs), the most common type of ASDs, efficiently meet varying process requirements by adjusting the frequency and voltage of the power supplied to an AC motor to enable it to operate over a wide speed range. External sensors monitor flow, liquid levels, or pressure and then transmit a signal to a controller that adjusts the frequency and speed to match process requirements.

  2. Adjustable Speed Drive Study, Part 1.

    SciTech Connect

    Wallace, Alan K.; Oregon State University. Dept. of Electrical and Computer Engineering.

    1989-08-01

    Advances in speed control for motors in recent years, notably those in power electronics, have widened the range of application for several adjustable speed drive (ASD) types to include the smaller horsepower sizes. The dc motor drive, formerly in almost universal use for speed control, is being challenged by the high efficiency induction motor/pulse width modulation (PWM) drive; and for special small horsepower size applications, by the permanent magnet motor/PWM inverter drive or by the switched reluctance motor drive. The main characteristics of the several ASD types suitable for small horsepower size applications are discussed, as well as their unwanted side effects: poor power factor, harmonic distortion of the supply, acoustic noise, and electromagnetic interference. A procedure is recommended for determining which, if any, ASD to use. 31 figs., 6 tabs.

  3. Adjustable Speed Drive Study, Part 2.

    SciTech Connect

    Wallace, Alan K.; Oregon State University. Dept. of Electrical and Computer Engineering.

    1989-08-01

    Advances in speed control for motors in recent years, notably those in power electronics, have widened the range of application for several adjustable speed drive (ASD) types to include the smaller horsepower sizes. The DC motor drive, formerly in almost universal use for speed control, is being challenged by the high efficiency induction motor/pulse width modulation (PWM) drive; and for special small horsepower size applications, by the permanent magnet motor/PWM inverter drive or by the switched reluctance motor drive. The main characteristics of the several ASD types suitable for small horsepower size applications are discussed, as well as their unwanted side effects: poor power factor, harmonic distortion of the supply, acoustic noise, and electromagnetic interference. A procedure is recommended for determining which, if any, ASD to use.

  4. Adjustable speed drives: Applications and R&D needs

    SciTech Connect

    Stefanovic, V.R.

    1995-09-01

    The largest opportunity for the growth of adjustable speed drives (ASDs) during the next 5-6 years is in pump, fan and compressor (PFC) applications where a constant, fixed speed operation is converted to adjustable speed in order to realize energy savings. Inverter supplied induction motors are and will continue to be predominately used in these applications. Over the long term (10-15 years), the greatest ASD growth is expected in large volume consumer applications: first in hybrid electric vehicles (EVs) and in residential heating, ventilation and air-conditioning (HVAC). Both induction and a variety of AC Permanent Magnet motors are expected to be the dominant technology in this new field. The traditional ASD applications in industries which require adjustable speed (such as machine tools, robotics, steel rolling, extruders, paper mill finishing lines, etc.) offer a relatively limited potential for above average ASD growth since most of these applications have already converted to electronic speed control. As a result, ASD growth in this sector will essentially track the growth of the corresponding industries. If realized, both short and long term ASD growth opportunities will result in significant advancements of ASD technology, which will then substantially affect all other, more fragmented, ASD applications. In fact, any single large volume ASD application will serve as a catalyst for improving ASD characteristics in all other ASD applications with the same voltage rating. ASD cost and reliability (defined in the context of application compatibility) are the two most important factors which will determine whether the ASD growth opportunities are realized. Conversely, any technological improvement which carries a cost increase will be restricted to niche applications, at best. Consequently, future R & D efforts should be directed to secure reduction in ASD cost and improvement in ASD reliability. A specific action plan is outlined in this report.

  5. Sequential control by speed drive for ac motor

    NASA Astrophysics Data System (ADS)

    Barsoum, Nader

    2012-11-01

    The speed drive for ac motor is widely used in the industrial field to allow direct control for the speed and torque without any feedback from the motor shaft. By using the ABB ACS800 speed drive unit, the speed and torque can be controlled using sequential control method. Sequential control is one of the application control method provided in the ABB ACS800 Drive, where a set of events or action performed in a particular order one after the other to control the speed and torque of the ac motor. It was claimed that sequential control method is using the preset seven constant speeds being provided in ABB ACS800 drive to control the speed and torque in a continuous and sequential manner. The characteristics and features of controlling the speed and torque using sequential control method can be investigated by observing the graphs and curves plotted which are obtained from the practical result. Sequential control can run either in the Direct Torque Control (DTC) or Scalar motor control mode. By using sequential control method, the ABB ACS800 drive can be programmed to run the motor automatically according to the time setting of the seven preset constant speeds. Besides, the intention of this project is to generate a new form of the experimental set up.

  6. Scalar control on speed drive for ac motor

    NASA Astrophysics Data System (ADS)

    Barsoum, Nader

    2012-11-01

    This paper aims to investigate the performance of ABB ACS800 variable speed drive operating under Scalar Control mode, and eventually develop a set of experimental procedures for undergraduate laboratory purposes. Scalar Control is the most widespread form of ac drive, for its low cost and simplicity especially implemented in the open loop mode. Scalar control is achieved by controlling the stator voltage and frequency, thus maintaining the motor's air-gap flux at a constant value. To illustrate the control method, the ac drive is configured according to the wiring diagram in the firmware manual that the drive control location can be both local and external. The drive is selected to operate under Factory application macro, whereby either ordinary speed control applications or constant speeds applications may be used. Under ordinary speed control, frequency reference signals are provided to the drive through the analogue input AI1. The drive will operate at the given frequency reference value throughout the operation regardless of any changes in the load. The torque speed curve moves along the speed axis with no changes to the shape as the supply frequencies changes. On the other hand, the drive allows three preset constant speed through digital inputs DI5 and DI6. The drive operate at a constant speed value over a time period, and only switch from one constant speed to another constant speed by triggering the two input switches. Scalar control is most suitable for applications not required high precision, such as blowers, fans and pumps.

  7. Corps of Engineers considers adjustable-speed generation

    SciTech Connect

    Not Available

    1993-04-01

    The US Army Corps of Engineers and the Bonneville Power Administration recently commissioned a study to assess the various aspects of adjustable-speed generation (also called variable-speed generation). Electronic Power Conditioning Inc., of Corvallis, Oregon, studied the cost, efficiency, and other operating implications of installing the necessary hardware to enable adjustable-speed generation at four Corps hydroelectric plants on the lower Snake River (Ice Harbor, Lower Monumental, Little Goose, and Lower Granite). Results of the study indicate that, while costly, five adjustable-speed options could be installed and operated on a practical basis. The Corps initiated the study to determine the cost for adding adjustable-speed generation at the four projects to improve fish survival. The Northwest Power Planning Council currently is considering proposals to modify operating procedures for hydroelectric projects on the Columbia River and its tributaries, including seasonal adjustments of pool levels behind dams to flush fish through the river system more rapidly. However, dropping pool levels significantly below normal levels may cause a loss in generating efficiency and a corresponding increase in fish mortality. Adjustable-speed generation is seen as a method for solving both problems

  8. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered adjustable hospital bed. 880.5100 Section 880.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An...

  9. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered adjustable hospital bed. 880.5100 Section 880.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An...

  10. Analysis, design, and control of a novel optically commutated adjustable-speed motor

    NASA Astrophysics Data System (ADS)

    Newman, Wyatt S.; Risch, Ivan; Zhang, Yuandao; Garverick, Steven; Inerfield, Michael

    1998-12-01

    This paper describes the analysis, design and control of a novel, single-phase motor with a unique behavior resulting from the use of rotating power electronics mounted to the motor armature. Coils on the armature are selectively shorted by power MOSFET's which rotate with the armature, and torque is produced by interaction between currents induced in the shorted coils and the magnetic field produced by a stationary field coil. Control is limited to the timing of which armature coils are to be shorted as a function of armature speed and angle, it is possible to modulate torque production and obtain torque or speed control using only single-phase ac power and without the use of brushes or permanent magnets. An electro-mechanical model for this type of motor is presented and validated with respect to experimentation. The results show promise for achieving low- cost, adjustable-speed drives using this novel method of rotating electronics, optical communications, and computed commutation.

  11. Explosive Products EOS: Adjustment for detonation speed and energy release

    SciTech Connect

    Menikoff, Ralph

    2014-09-05

    Propagating detonation waves exhibit a curvature effect in which the detonation speed decreases with increasing front curvature. The curvature effect is due to the width of the wave profile. Numerically, the wave profile depends on resolution. With coarse resolution, the wave width is too large and results in a curvature effect that is too large. Consequently, the detonation speed decreases as the cell size is increased. We propose a modification to the products equation of state (EOS) to compensate for the effect of numerical resolution; i.e., to increase the CJ pressure in order that a simulation propagates a detonation wave with a speed that is on average correct. The EOS modification also adjusts the release isentrope to correct the energy release.

  12. Generating apparatus with an adjustable speed change mechanism

    SciTech Connect

    Kaneyuki, K.

    1987-03-17

    A generating apparatus is described comprising: a charging generator having a rotating input shaft; a rotating input body adapted to be connected to a motor so as to be rotated thereby, the rotating input body comprising a cylindrical body surrounding the input shaft; an adjustable speed change mechanism comprising a planetary cone reduction gear housed within the rotating input body and operatively associated with the rotating input body and the input shaft of the charging generator so as to transmit rotational force from the rotating input body to the input shaft. The planetary cone reduction gear comprises: a cone support ring mounted on the input shaft and adapted to rotate with respect thereto, a plurality of planetary cones having stems which are rotatably mounted on the cone support ring, the axis of each of the planetary cones being disposed such that a line which is parallel to the input shaft can be drawn from the vertex of each cone to its base along its top surface, a stationary guide ring which surrounds the input shaft and frictionally engages the peripheral surfaces of the stems of the planetary cones, a speed change ring surrounding the input shaft and having an inner surface frictionally engaging the top surfaces of the planetary cones. The speed change ring is supported by the rotating input body so as to rotate together with the input body and adapted to move in the axial direction of the input body with respect thereto.

  13. Variable-frequency inverter controls torque, speed, and braking in ac induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J.

    1974-01-01

    Dc to ac inverter provides optimum frequency and voltage to ac induction motor, in response to different motor-load and speed requirements. Inverter varies slip frequency of motor in proportion to required torque. Inverter protects motor from high current surges, controls negative slip to apply braking, and returns energy stored in momentum of load to dc power source.

  14. A high-speed TVC system for full-range AC traceability

    SciTech Connect

    Julie, L.

    1994-12-31

    A difficult and important region in the AC traceability chain lies in the higher voltage ranges from 30 volts to 1000 volts at frequencies between 100 khz and 1 Mhz. This paper describes recent developments to improve the accuracy/speed performance of AC voltage buildup over thes ranges.

  15. Magnetically Coupled Adjustable Speed Motor Drives - Motor Tip Sheet #13

    SciTech Connect

    2008-07-01

    Alternating current electric motors rotate at a nearly constant speed that is determined by motor design and line frequency. Energy savings of 50% or more may be available when fixed speed systems are modified to allow the motor speed to match variable load requirements of a centrifugal fan or pump.

  16. Pentazocine transport by square-wave AC iontophoresis with an adjusted duty cycle.

    PubMed

    Ogami, Saori; Hayashi, Shizuka; Shibaji, Takao; Umino, Masahiro

    2008-03-01

    So far, pentazocine iontophoresis has never been studied, although pentazocine is widely used in pain management. The purpose of this study was to determine whether pentazocine transportation through a cellophane membrane could be enhanced using square-wave alternating current (AC) iontophoresis with an adjusted duty cycle and dependence on the voltage and the duty cycle. Voltages of 10, 25 and 40 V with duty cycles of 50%, 51%, 52%, 53%, 54% and 55% were applied for 60 minutes at a high frequency of 1 MHz to diffusion cells on both sides of a cellophane membrane. The donor compartment was filled with a solution containing pentazocine. Square-wave AC iontophoresis with an adjusted duty cycle enhanced pentazocine transportation at higher voltages and duty cycles. These results suggested that the direct current (DC) component of the square-wave AC played an important role in enhancing pentazocine transportation despite changes in polarity at very high frequency of 1 MHz. The higher voltages and duty cycles induced a pH change. The practical electrical conditions that could be applied clinically were 25 V with a 54% duty cycle or 40 V with a 53% duty cycle.

  17. Extended cage adjustable speed electric motors and drive packages

    DOEpatents

    Hsu, J.S.

    1999-03-23

    The rotor cage of a motor is extended, a second stator is coupled to this extended rotor cage, and the windings have the same number of poles. The motor torque and speed can be controlled by either injecting energy into or extracting energy out from the rotor cage. The motor produces less harmonics than existing doubly-fed motors. Consequently, a new type of low cost, high efficiency drive is produced. 12 figs.

  18. Extended cage adjustable speed electric motors and drive packages

    DOEpatents

    Hsu, John S.

    1999-01-01

    The rotor cage of a motor is extended, a second stator is coupled to this extended rotor cage, and the windings have the same number of poles. The motor torque and speed can be controlled by either injecting energy into or extracting energy out from the rotor cage. The motor produces less harmonics than existing doubly-fed motors. Consequently, a new type of low cost, high efficiency drive is produced.

  19. Instantaneous characteristics simulation and analysis on three-level brushless AC synchronous generators of aeronautic constant speed and frequency AC power system

    NASA Astrophysics Data System (ADS)

    Ma, Xiaohe; Shen, Songhua

    2006-11-01

    This paper mainly introduces theoretical analysis and experimental results of instantaneous characteristics on a certain three level brushless three-phase AC synchronous generators. The analysis, modeling and simulations with Simplorer software of Ansoft Company are carried out. It establishes three level generator models, gives theoretical relation matrix equation, and simulates some instantaneous characteristics. Design of the system requires reliable simulation tools with comprehensive component libraries capable of dealing with complex system behavior. The simulation results verify that the proposed system model can efficiently simulate the instantaneous characteristics of the real AC generator system. It gives better design experiences and digital methods for aeronautic constant speed and frequency AC power system.

  20. Variable frequency inverter for ac induction motors with torque, speed and braking control

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1975-01-01

    A variable frequency inverter was designed for driving an ac induction motor which varies the frequency and voltage to the motor windings in response to varying torque requirements for the motor so that the applied voltage amplitude and frequency are of optimal value for any motor load and speed requirement. The slip frequency of the motor is caused to vary proportionally to the torque and feedback is provided so that the most efficient operating voltage is applied to the motor. Winding current surge is limited and a controlled negative slip causes motor braking and return of load energy to a dc power source.

  1. Adjustable Speed Drive Project for Teaching a Servo Systems Course Laboratory

    ERIC Educational Resources Information Center

    Rodriguez-Resendiz, J.; Herrera-Ruiz, G.; Rivas-Araiza, E. A.

    2011-01-01

    This paper describes an adjustable speed drive for a three-phase motor, which has been implemented as a design for a servo system laboratory course in an engineering curriculum. The platform is controlled and analyzed in a LabVIEW environment and run on a PC. Theory is introduced in order to show the sensorless algorithms. These are computed by…

  2. Probability distribution of surface wind speed induced by convective adjustment on Venus

    NASA Astrophysics Data System (ADS)

    Yamamoto, Masaru

    2017-03-01

    The influence of convective adjustment on the spatial structure of Venusian surface wind and probability distribution of its wind speed is investigated using an idealized weather research and forecasting model. When the initially uniform wind is much weaker than the convective wind, patches of both prograde and retrograde winds with scales of a few kilometers are formed during active convective adjustment. After the active convective adjustment, because the small-scale convective cells and their related vertical momentum fluxes dissipate quickly, the large-scale (>4 km) prograde and retrograde wind patches remain on the surface and in the longitude-height cross-section. This suggests the coexistence of local prograde and retrograde flows, which may correspond to those observed by Pioneer Venus below 10 km altitude. The probability distributions of surface wind speed V during the convective adjustment have a similar form in different simulations, with a sharp peak around ∼0.1 m s-1 and a bulge developing on the flank of the probability distribution. This flank bulge is associated with the most active convection, which has a probability distribution with a peak at the wind speed 1.5-times greater than the Weibull fitting parameter c during the convective adjustment. The Weibull distribution P(> V) (= exp[-(V/c)k]) with best-estimate coefficients of Lorenz (2016) is reproduced during convective adjustments induced by a potential energy of ∼7 × 107 J m-2, which is calculated from the difference in total potential energy between initially unstable and neutral states. The maximum vertical convective heat flux magnitude is proportional to the potential energy of the convective adjustment in the experiments with the initial unstable-layer thickness altered. The present work suggests that convective adjustment is a promising process for producing the wind structure with occasionally generating surface winds of ∼1 m s-1 and retrograde wind patches.

  3. Comparison of the Accuracy and Speed of Transient Mobile A/C System Simulation Models: Preprint

    SciTech Connect

    Kiss, T.; Lustbader, J.

    2014-03-01

    The operation of air conditioning (A/C) systems is a significant contributor to the total amount of fuel used by light- and heavy-duty vehicles. Therefore, continued improvement of the efficiency of these mobile A/C systems is important. Numerical simulation has been used to reduce the system development time and to improve the electronic controls, but numerical models that include highly detailed physics run slower than desired for carrying out vehicle-focused drive cycle-based system optimization. Therefore, faster models are needed even if some accuracy is sacrificed. In this study, a validated model with highly detailed physics, the 'Fully-Detailed' model, and two models with different levels of simplification, the 'Quasi-Transient' and the 'Mapped- Component' models, are compared. The Quasi-Transient model applies some simplifications compared to the Fully-Detailed model to allow faster model execution speeds. The Mapped-Component model is similar to the Quasi-Transient model except instead of detailed flow and heat transfer calculations in the heat exchangers, it uses lookup tables created with the Quasi-Transient model. All three models are set up to represent the same physical A/C system and the same electronic controls. Speed and results of the three model versions are compared for steady state and transient operation. Steady state simulated data are also compared to measured data. The results show that the Quasi-Transient and Mapped-Component models ran much faster than the Fully-Detailed model, on the order of 10- and 100-fold, respectively. They also adequately approach the results of the Fully-Detailed model for steady-state operation, and for drive cycle-based efficiency predictions

  4. Dynamic model tracking design for low inertia, high speed permanent magnet ac motors.

    PubMed

    Stewart, P; Kadirkamanathan, V

    2004-01-01

    Permanent magnet ac (PMAC) motors have existed in various configurations for many years. The advent of rare-earth magnets and their associated highly elevated levels of magnetic flux makes the permanent magnet motor attractive for many high performance applications from computer disk drives to all electric racing cars. The use of batteries as a prime storage element carries a cost penalty in terms of the unladen weight of the vehicle. Minimizing this cost function requires the minimum electric motor size and weight to be specified, while still retaining acceptable levels of output torque. This tradeoff can be achieved by applying a technique known as flux weakening which will be investigated in this paper. The technique allows the speed range of a PMAC motor to be greatly increased, giving a constant power range of more than 4:1. A dynamic model reference controller is presented which has advantages in ease of implementation, and is particularly suited to dynamic low inertia applications such as clutchless gear changing in high performance electric vehicles. The benefits of this approach are to maximize the torque speed envelope of the motor, particularly advantageous when considering low inertia operation. The controller is examined experimentally, confirming the predicted performance.

  5. Insect–computer hybrid legged robot with user-adjustable speed, step length and walking gait

    PubMed Central

    Cao, Feng; Zhang, Chao; Choo, Hao Yu

    2016-01-01

    We have constructed an insect–computer hybrid legged robot using a living beetle (Mecynorrhina torquata; Coleoptera). The protraction/retraction and levation/depression motions in both forelegs of the beetle were elicited by electrically stimulating eight corresponding leg muscles via eight pairs of implanted electrodes. To perform a defined walking gait (e.g. gallop), different muscles were individually stimulated in a predefined sequence using a microcontroller. Different walking gaits were performed by reordering the applied stimulation signals (i.e. applying different sequences). By varying the duration of the stimulation sequences, we successfully controlled the step frequency and hence the beetle's walking speed. To the best of our knowledge, this paper presents the first demonstration of living insect locomotion control with a user-adjustable walking gait, step length and walking speed. PMID:27030043

  6. Insect-computer hybrid legged robot with user-adjustable speed, step length and walking gait.

    PubMed

    Cao, Feng; Zhang, Chao; Choo, Hao Yu; Sato, Hirotaka

    2016-03-01

    We have constructed an insect-computer hybrid legged robot using a living beetle (Mecynorrhina torquata; Coleoptera). The protraction/retraction and levation/depression motions in both forelegs of the beetle were elicited by electrically stimulating eight corresponding leg muscles via eight pairs of implanted electrodes. To perform a defined walking gait (e.g., gallop), different muscles were individually stimulated in a predefined sequence using a microcontroller. Different walking gaits were performed by reordering the applied stimulation signals (i.e., applying different sequences). By varying the duration of the stimulation sequences, we successfully controlled the step frequency and hence the beetle's walking speed. To the best of our knowledge, this paper presents the first demonstration of living insect locomotion control with a user-adjustable walking gait, step length and walking speed.

  7. Nature and measurements of torque ripple of permanent-magnet adjustable-speed motors

    SciTech Connect

    Hsu, J.S.; Scoggins, B.P.; Scudiere, M.B.; Marlino, L.D.; Adams, D.J.; Pillay, P.

    1995-08-01

    Torque ripple of permanent-magnet motors can be classified into four types depending on the nature of their origin. The four types are pulsating torque, fluctuating torque, reluctance cogging torque, and inertia and mechanical system torque. Pulsating torques are inherently produced by the trapezoidal back-emf`s and trapezoidal currents used in certain permanent-magnet adjustable-speed motors. The torque ripples caused by pulsating torques may be reduced by purposely produced fluctuating counter torques. Air-gap torque measurements are conducted on a sample motor. Experimental results agree with theoretical expectations.

  8. Dynamic melting and impurity particle tracking in continuously adjustable AC magnetic field

    NASA Astrophysics Data System (ADS)

    Bojarevics, V.; Pericleous, K.

    2016-07-01

    The analysis of semi-levitation melting is extended to account for the presence of particles (impurities, broken metal dendrite agglomerates, bubbles) during the full melting cycle simulated numerically using the pseudo-spectral schemes. The AC coil is dynamically moving with the melt front progress, while the generated Joule heat serves to enhance the melting rate. The electromagnetic force is decomposed into the time average and the oscillating parts. The time average effects on the particle transport are investigated previously using approximations derived for a locally uniform magnetic field. This paper presents expressions for the skin-layer type of the AC force containing also the pulsating part which contributes to the particle drag by the ‘history’ and ‘added mass’ contributions. The intense turbulence in the bulk of molten metal additionally contributes to the particle dispersion. The paper attempts to demonstrate the importance of each of the mentioned effects onto the particle transport during the melting until the final pouring stage. The method could be extended to similar AC field controlled melting/solidification processes.

  9. Passive wide spectrum harmonic filter for adjustable speed drives in oil and gas industry

    NASA Astrophysics Data System (ADS)

    Al Jaafari, Khaled Ali

    Non-linear loads such as variable speed drives constitute the bulky load of oil and gas industry power systems. They are widely used in driving induction and permanent magnet motors for variable speed applications. That is because variable speed drives provide high static and dynamic performance. Moreover, they are known of their high energy efficiency and high motion quality, and high starting torque. However, these non-linear loads are main sources of current and voltage harmonics and lower the quality of electric power system. In fact, it is the six-pulse and twelve-pulse diode and thyristor rectifiers that spoil the AC power line with the dominant harmonics (5th, 7th, 11th). They provide DC voltage to the inverter of the variable speed drives. Typical problems that arise from these harmonics are Harmonic resonances', harmonic losses, interference with electronic equipment, and line voltage distortion at the Point of Common Coupling (PCC). Thus, it is necessary to find efficient, reliable, and economical harmonic filters. The passive filters have definite advantage over active filters in terms of components count, cost and reliability. Reliability and maintenance is a serious issue in drilling rigs which are located in offshore and onshore with extreme operating conditions. Passive filters are tuned to eliminate a certain frequency and therefore there is a need to equip the system with more than one passive filter to eliminate all unwanted frequencies. An alternative solution is Wide Spectrum Harmonic passive filter. The wide spectrum harmonic filters are becoming increasingly popular in these applications and found to overcome some of the limitations of conventional tuned passive filter. The most important feature of wide spectrum harmonic passive filters is that only one capacitor is required to filter a wide range of harmonics. Wide spectrum filter is essentially a low-pass filter for the harmonic at fundamental frequency. It can also be considered as a

  10. Fifteen Years of Operation at NASA's National Transonic Facility with the World's Largest Adjustable Speed Drive

    NASA Technical Reports Server (NTRS)

    Sydnor, George H.; Bhatia, Ram; Krattiger, Hansueli; Mylius, Justus; Schafer, D.

    2012-01-01

    In September 1995, a project was initiated to replace the existing drive line at NASA's most unique transonic wind tunnel, the National Transonic Facility (NTF), with a single 101 MW synchronous motor driven by a Load Commutated Inverter (LCI). This Adjustable Speed Drive (ASD) system also included a custom four-winding transformer, harmonic filter, exciter, switch gear, control system, and feeder cable. The complete system requirements and design details have previously been presented and published [1], as well as the commissioning and acceptance test results [2]. The NTF was returned to service in December 1997 with the new drive system powering the fan. Today, this installation still represents the world s largest horizontal single motor/drive combination. This paper describes some significant events that occurred with the drive system during the first 15 years of service. These noteworthy issues are analyzed and root causes presented. Improvements that have substantially increased the long term viability of the system are given.

  11. Distinct mechanisms mediate speed-accuracy adjustments in cortico-subthalamic networks

    PubMed Central

    Herz, Damian M; Tan, Huiling; Brittain, John-Stuart; Fischer, Petra; Cheeran, Binith; Green, Alexander L; FitzGerald, James; Aziz, Tipu Z; Ashkan, Keyoumars; Little, Simon; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Bogacz, Rafal; Brown, Peter

    2017-01-01

    Optimal decision-making requires balancing fast but error-prone and more accurate but slower decisions through adjustments of decision thresholds. Here, we demonstrate two distinct correlates of such speed-accuracy adjustments by recording subthalamic nucleus (STN) activity and electroencephalography in 11 Parkinson’s disease patients during a perceptual decision-making task; STN low-frequency oscillatory (LFO) activity (2–8 Hz), coupled to activity at prefrontal electrode Fz, and STN beta activity (13–30 Hz) coupled to electrodes C3/C4 close to motor cortex. These two correlates differed not only in their cortical topography and spectral characteristics but also in the relative timing of recruitment and in their precise relationship with decision thresholds. Increases of STN LFO power preceding the response predicted increased thresholds only after accuracy instructions, while cue-induced reductions of STN beta power decreased thresholds irrespective of instructions. These findings indicate that distinct neural mechanisms determine whether a decision will be made in haste or with caution. DOI: http://dx.doi.org/10.7554/eLife.21481.001 PMID:28137358

  12. Does movement planning follow Fitts' law? Scaling anticipatory postural adjustments with movement speed and accuracy.

    PubMed

    Bertucco, M; Cesari, P

    2010-11-24

    We wanted to determine whether movement planning followed Fitts' law by investigating the relationship between movement planning and movement performance in experienced dancers executing a typical classical ballet step in which the big toe was pointed to targets at different distances and of different widths so as to obtain several indices of difficulty (ID). Movement time, velocity and variability at the target were the variables of movement performance kinematics; movement planning was evaluated by analysis of anticipatory postural adjustments (APAs) to assess their modulation at different IDs. Movement time and peak of velocity were found to scale with the ID only when individual movement distance across target widths was entered into the analysis. APA magnitude and duration both scaled according to movement parameters but not in the same way. APA magnitude scaled with movement velocity, while APA duration was sensitive to the amplitude-to-accuracy ratio following the ID for movements performed in the shortest time interval when on-line feedback control is probably not available. Here we show that timing of muscle activation acts as an independent central command that triggers fine-tuning for speed-accuracy trade-off.

  13. PV Array Driven Adjustable Speed Drive for a Lunar Base Heat Pump

    NASA Technical Reports Server (NTRS)

    Domijan, Alexander, Jr.; Buchh, Tariq Aslam

    1995-01-01

    A study of various aspects of Adjustable Speed Drives (ASD) is presented. A summary of the relative merits of different ASD systems presently in vogue is discussed. The advantages of using microcomputer based ASDs is now widely understood and accepted. Of the three most popular drive systems, namely the Induction Motor Drive, Switched Reluctance Motor Drive and Brushless DC Motor Drive, any one may be chosen. The choice would depend on the nature of the application and its requirements. The suitability of the above mentioned drive systems for a photovoltaic array driven ASD for an aerospace application are discussed. The discussion is based on the experience of the authors, various researchers and industry. In chapter 2 a PV array power supply scheme has been proposed, this scheme will have an enhanced reliability in addition to the other known advantages of the case where a stand alone PV array is feeding the heat pump. In chapter 3 the results of computer simulation of PV array driven induction motor drive system have been included. A discussion on these preliminary simulation results have also been included in this chapter. Chapter 4 includes a brief discussion on various control techniques for three phase induction motors. A discussion on different power devices and their various performance characteristics is given in Chapter 5.

  14. Establishing force and speed training targets for lumbar spine high-velocity, low-amplitude chiropractic adjustments*

    PubMed Central

    Owens, Edward F.; Hosek, Ronald S.; Sullivan, Stephanie G.B.; Russell, Brent S.; Mullin, Linda E.; Dever, Lydia L.

    2016-01-01

    Objective: We developed an adjusting bench with a force plate supporting the lumbar portion to measure loads transmitted during lumbar manual adjustment. It will be used to provide force-feedback to enhance student learning in technique labs. The study goal is to define the learning target loads and speeds, with instructors as expert models. Methods: A total of 11 faculty members experienced in teaching Gonstead technique methods performed 81 simulated adjustments on a mannequin on the force plate. Adjustments were along 9 lumbopelvic “listings” at 3 load levels: light, normal, and heavy. We analyzed the thrusts to find preload, peak load, duration, and thrust rate. Results: Analysis of 891 thrusts showed wide variations between doctors. Peak loads ranged from 100 to 1400 N. All doctors showed clear distinctions between peak load levels, but there was overlap between high and low loads. Thrust rates were more uniform across doctors, averaging 3 N/ms. Conclusion: These faculty members delivered a range of thrusts, not unlike those seen in the literature for high velocity, low amplitude manipulation. We have established at least minimum force and speed targets for student performance, but more work must be done to create a normative adjustment to guide refinement of student learning. PMID:26600272

  15. High-Speed Visualization of Evaporation Phenomena from Tungsten Based Electrode in Multi-Phase AC Arc

    NASA Astrophysics Data System (ADS)

    Tanaka, Manabu; Hashizume, Taro; Imatsuji, Tomoyuki; Nawata, Yushi; Watanabe, Takayuki

    2015-09-01

    A multi-phase AC arc has been developed for applications in various fields of engineering because it possesses unique advantages such as high energy efficiency. However, understanding of fundamental phenomena in the multi-phase AC arc is still insufficient for practical use. Purpose of this study is to investigate electrode erosion mechanism by high-speed visualization of the electrode metal vapor in the arc. Results indicated that the electrode mainly evaporated at anodic period, leading to the arc constriction. Moreover, evaporation of W electrode with 2wt% La2O3 at the anodic period was much higher than that with 2wt% ThO2. This can be explained by different properties of these oxide additives. Evaporation of the oxide additive resulted in the arc constriction, which accelerated the evaporation of W electrode. Therefore, addition of La2O3 with lower melting and boiling point than ThO2 lead to stronger arc constriction, resulting in severer evaporation of W electrode.

  16. Water striders adjust leg movement speed to optimize takeoff velocity for their morphology

    NASA Astrophysics Data System (ADS)

    Yang, Eunjin; Son, Jae Hak; Lee, Sang-Im; Jablonski, Piotr G.; Kim, Ho-Young

    2016-12-01

    Water striders are water-walking insects that can jump upwards from the water surface. Quick jumps allow striders to avoid sudden dangers such as predators' attacks, and therefore their jumping is expected to be shaped by natural selection for optimal performance. Related species with different morphological constraints could require different jumping mechanics to successfully avoid predation. Here we show that jumping striders tune their leg rotation speed to reach the maximum jumping speed that water surface allows. We find that the leg stroke speeds of water strider species with different leg morphologies correspond to mathematically calculated morphology-specific optima that maximize vertical takeoff velocity by fully exploiting the capillary force of water. These results improve the understanding of correlated evolution between morphology and leg movements in small jumping insects, and provide a theoretical basis to develop biomimetic technology in semi-aquatic environments.

  17. Water striders adjust leg movement speed to optimize takeoff velocity for their morphology

    PubMed Central

    Yang, Eunjin; Son, Jae Hak; Lee, Sang-im; Jablonski, Piotr G.; Kim, Ho-Young

    2016-01-01

    Water striders are water-walking insects that can jump upwards from the water surface. Quick jumps allow striders to avoid sudden dangers such as predators' attacks, and therefore their jumping is expected to be shaped by natural selection for optimal performance. Related species with different morphological constraints could require different jumping mechanics to successfully avoid predation. Here we show that jumping striders tune their leg rotation speed to reach the maximum jumping speed that water surface allows. We find that the leg stroke speeds of water strider species with different leg morphologies correspond to mathematically calculated morphology-specific optima that maximize vertical takeoff velocity by fully exploiting the capillary force of water. These results improve the understanding of correlated evolution between morphology and leg movements in small jumping insects, and provide a theoretical basis to develop biomimetic technology in semi-aquatic environments. PMID:27924805

  18. Dynamic Modeling of Adjustable-Speed Pumped Storage Hydropower Plant: Preprint

    SciTech Connect

    Muljadi, E.; Singh, M.; Gevorgian, V.; Mohanpurkar, M.; Havsapian, R.; Koritarov, V.

    2015-04-06

    Hydropower is the largest producer of renewable energy in the U.S. More than 60% of the total renewable generation comes from hydropower. There is also approximately 22 GW of pumped storage hydropower (PSH). Conventional PSH uses a synchronous generator, and thus the rotational speed is constant at synchronous speed. This work details a hydrodynamic model and generator/power converter dynamic model. The optimization of the hydrodynamic model is executed by the hydro-turbine controller, and the electrical output real/reactive power is controlled by the power converter. All essential controllers to perform grid-interface functions and provide ancillary services are included in the model.

  19. Adjustments with running speed reveal neuromuscular adaptations during landing associated with high mileage running training.

    PubMed

    Verheul, Jasper; Clansey, Adam C; Lake, Mark J

    2017-03-01

    It remains to be determined whether running training influences the amplitude of lower limb muscle activations before and during the first half of stance and whether such changes are associated with joint stiffness regulation and usage of stored energy from tendons. Therefore, the aim of this study was to investigate neuromuscular and movement adaptations before and during landing in response to running training across a range of speeds. Two groups of high mileage (HM; >45 km/wk, n = 13) and low mileage (LM; <15 km/wk, n = 13) runners ran at four speeds (2.5-5.5 m/s) while lower limb mechanics and electromyography of the thigh muscles were collected. There were few differences in prelanding activation levels, but HM runners displayed lower activations of the rectus femoris, vastus medialis, and semitendinosus muscles postlanding, and these differences increased with running speed. HM runners also demonstrated higher initial knee stiffness during the impact phase compared with LM runners, which was associated with an earlier peak knee flexion velocity, and both were relatively unchanged by running speed. In contrast, LM runners had higher knee stiffness during the slightly later weight acceptance phase and the disparity was amplified with increases in speed. It was concluded that initial knee joint stiffness might predominantly be governed by tendon stiffness rather than muscular activations before landing. Estimated elastic work about the ankle was found to be higher in the HM runners, which might play a role in reducing weight acceptance phase muscle activation levels and improve muscle activation efficiency with running training.NEW & NOTEWORTHY Although neuromuscular factors play a key role during running, the influence of high mileage training on neuromuscular function has been poorly studied, especially in relation to running speed. This study is the first to demonstrate changes in neuromuscular conditioning with high mileage training, mainly characterized by

  20. A Novel Adjustment Method for Shearer Traction Speed through Integration of T-S Cloud Inference Network and Improved PSO

    PubMed Central

    Si, Lei; Wang, Zhongbin; Yang, Yinwei

    2014-01-01

    In order to efficiently and accurately adjust the shearer traction speed, a novel approach based on Takagi-Sugeno (T-S) cloud inference network (CIN) and improved particle swarm optimization (IPSO) is proposed. The T-S CIN is built through the combination of cloud model and T-S fuzzy neural network. Moreover, the IPSO algorithm employs parameter automation adjustment strategy and velocity resetting to significantly improve the performance of basic PSO algorithm in global search and fine-tuning of the solutions, and the flowchart of proposed approach is designed. Furthermore, some simulation examples are carried out and comparison results indicate that the proposed method is feasible, efficient, and is outperforming others. Finally, an industrial application example of coal mining face is demonstrated to specify the effect of proposed system. PMID:25506358

  1. A novel adjustment method for shearer traction speed through integration of T-S cloud inference network and improved PSO.

    PubMed

    Si, Lei; Wang, Zhongbin; Liu, Xinhua; Yang, Yinwei; Zhang, Lin

    2014-01-01

    In order to efficiently and accurately adjust the shearer traction speed, a novel approach based on Takagi-Sugeno (T-S) cloud inference network (CIN) and improved particle swarm optimization (IPSO) is proposed. The T-S CIN is built through the combination of cloud model and T-S fuzzy neural network. Moreover, the IPSO algorithm employs parameter automation adjustment strategy and velocity resetting to significantly improve the performance of basic PSO algorithm in global search and fine-tuning of the solutions, and the flowchart of proposed approach is designed. Furthermore, some simulation examples are carried out and comparison results indicate that the proposed method is feasible, efficient, and is outperforming others. Finally, an industrial application example of coal mining face is demonstrated to specify the effect of proposed system.

  2. Free-standing few-layered graphene oxide films: selective, steady and lasting permeation of organic molecules with adjustable speeds

    NASA Astrophysics Data System (ADS)

    Huang, Tao; An, Qi; Luan, Xinglong; Zhang, Qian; Zhang, Yihe

    2016-01-01

    A variety of small molecules with diameters around 1 nm possess a range of functions, such as antibiotic, antimicrobic, anticoagulant, pesticidal and chemotherapy effects, making these molecules especially useful in various applications ranging from medical treatment to environmental microbiological control. However, the long-term steady delivery (release or permeation) of these small molecules with adjustable and controllable speeds has remained an especially challenging task. In this study, we prepared covalently cross-linked free-standing few-layered GO films using a layer-by-layer technique in combination with photochemical cross-linkages, and achieved a controlled release of positively charged, negatively charged, and zwitterionic small molecules with adjustable and controllable speeds. The steady delivery of the small molecule lasted up to 9 days. Other functionalities, such as graphene-enhanced Raman spectra and electrochemical properties that could also be integrated or employed in delivery systems, were also studied for our films. We expect the special molecular delivery properties of our films to lead to new possibilities in drug/fertilizer delivery and environmental microbiological control applications.A variety of small molecules with diameters around 1 nm possess a range of functions, such as antibiotic, antimicrobic, anticoagulant, pesticidal and chemotherapy effects, making these molecules especially useful in various applications ranging from medical treatment to environmental microbiological control. However, the long-term steady delivery (release or permeation) of these small molecules with adjustable and controllable speeds has remained an especially challenging task. In this study, we prepared covalently cross-linked free-standing few-layered GO films using a layer-by-layer technique in combination with photochemical cross-linkages, and achieved a controlled release of positively charged, negatively charged, and zwitterionic small molecules with

  3. African elephants adjust speed in response to surface-water constraint on foraging during the dry-season.

    PubMed

    Chamaillé-Jammes, Simon; Mtare, Godfrey; Makuwe, Edwin; Fritz, Hervé

    2013-01-01

    Most organisms need to acquire various resources to survive and reproduce. Individuals should adjust their behavior to make optimal use of the landscape and limit the costs of trade-offs emerging from the use of these resources. Here we study how African elephants Loxodonta africana travel to foraging places between regular visits to waterholes. Elephant herds were tracked using GPS collars during two consecutive dry seasons in Hwange National Park, Zimbabwe. We segmented each individual movement track at each visit to water to define foraging trips, and then used trip-level statistics to build an understanding of movement strategies. Travel speed within these individually-consistent movement bouts was also analyzed to understand if speed was better linked to distance to water or progression in the trip over time. We found that elephants went further from water when drinking less often, which could result from a trade-off between drinking and foraging in less depleted, far from water, places. Speed increased towards the beginning and the end of the trips, and was also greater than observed during the wet season, suggesting that elephants were trying to save time. Numerous short trips traveled at greater speed, particularly when commuting to a different waterhole, was tentatively explained by the inability to drink at specific waterholes due to intra-specific interference. Unexpectedly elephants did not always minimize travel time by drinking at the closest waterhole, but the extra distance traveled remained never more than a few kilometers. Our results show how individuals may adjust movement behavior to deal with resource trade-offs at the landscape scale. We also highlight how behavioral context, here progression in the trip, may be more important than spatial context, here distance to water, in explaining animal movement patterns.

  4. High speed optical coherence microscopy with autofocus adjustment and a miniaturized endoscopic imaging probe

    PubMed Central

    Aguirre, Aaron D.; Sawinski, Juergen; Huang, Shu-Wei; Zhou, Chao; Denk, Winfried; Fujimoto, James G.

    2010-01-01

    Optical coherence microscopy (OCM) is a promising technique for high resolution cellular imaging in human tissues. An OCM system for high-speed en face cellular resolution imaging was developed at 1060 nm wavelength at frame rates up to 5 Hz with resolutions of < 4 µm axial and < 2 µm transverse. The system utilized a novel polarization compensation method to combat wavelength dependent source polarization and achieve broadband electro-optic phase modulation compatible with ultrahigh axial resolution. In addition, the system incorporated an auto-focusing feature that enables precise, near real-time alignment of the confocal and coherence gates in tissue, allowing user-friendly optimization of image quality during the imaging procedure. Ex vivo cellular images of human esophagus, colon, and cervix as well as in vivo results from human skin are presented. Finally, the system design is demonstrated with a miniaturized piezoelectric fiber-scanning probe which can be adapted for laparoscopic and endoscopic imaging applications. PMID:20389435

  5. Trial-to-trial adjustments of speed-accuracy trade-offs in premotor and primary motor cortex.

    PubMed

    Thura, David; Guberman, Guido; Cisek, Paul

    2017-02-01

    Recent studies have shown that activity in sensorimotor structures varies depending on the speed-accuracy trade-off (SAT) context in which a decision is made. Here we tested the hypothesis that the same areas also reflect a more local adjustment of SAT established between individual trials, based on the outcome of the previous decision. Two monkeys performed a reaching decision task in which sensory evidence continuously evolves during the time course of a trial. In two SAT contexts, we compared neural activity in trials following a correct choice vs. those following an error. In dorsal premotor cortex (PMd), we found that 23% of cells exhibited significantly weaker baseline activity after error trials, and for ∼30% of these this effect persisted into the deliberation epoch. These cells also contributed to the process of combining sensory evidence with the growing urgency to commit to a choice. We also found that the activity of 22% of PMd cells was increased after error trials. These neurons appeared to carry less information about sensory evidence and time-dependent urgency. For most of these modulated cells, the effect was independent of whether the previous error was expected or unexpected. We found similar phenomena in primary motor cortex (M1), with 25% of cells decreasing and 34% increasing activity after error trials, but unlike PMd, these neurons showed less clear differences in their response properties. These findings suggest that PMd and M1 belong to a network of brain areas involved in SAT adjustments established using the recent history of reinforcement.

  6. Effects of priming exercise on the speed of adjustment of muscle oxidative metabolism at the onset of moderate-intensity step transitions in older adults.

    PubMed

    De Roia, Gabriela; Pogliaghi, Silvia; Adami, Alessandra; Papadopoulou, Christina; Capelli, Carlo

    2012-05-15

    Aging is associated with a functional decline of the oxidative metabolism due to progressive limitations of both O(2) delivery and utilization. Priming exercise (PE) increases the speed of adjustment of oxidative metabolism during successive moderate-intensity transitions. We tested the hypothesis that such improvement is due to a better matching of O(2) delivery to utilization within the working muscles. In 21 healthy older adults (65.7 ± 5 yr), we measured contemporaneously noninvasive indexes of the overall speed of adjustment of the oxidative metabolism (i.e., pulmonary Vo(2) kinetics), of the bulk O(2) delivery (i.e., cardiac output), and of the rate of muscle deoxygenation (i.e., deoxygenated hemoglobin, HHb) during moderate-intensity step transitions, either with (ModB) or without (ModA) prior PE. The local matching of O(2) delivery to utilization was evaluated by the ΔHHb/ΔVo(2) ratio index. The overall speed of adjustment of the Vo(2) kinetics was significantly increased in ModB compared with ModA (P < 0.05). On the contrary, the kinetics of cardiac output was unaffected by PE. At the muscle level, ModB was associated with a significant reduction of the "overshoot" in the ΔHHb/ΔVo(2) ratio compared with ModA (P < 0.05), suggesting an improved O(2) delivery. Our data are compatible with the hypothesis that, in older adults, PE, prior to moderate-intensity exercise, beneficially affects the speed of adjustment of oxidative metabolism due to an acute improvement of the local matching of O(2) delivery to utilization.

  7. A semelparous fish continues upstream migration when exposed to alarm cue, but adjusts movement speed and timing

    USGS Publications Warehouse

    Luhring, Thomas M; Meckley, Trevor D.; Johnson, Nicholas S.; Siefkes, Michael J.; Hume, John B.; Wagner, C. Michael

    2016-01-01

    Animals make trade-offs between predation risk and pursuit of opportunities such as foraging and reproduction. Trade-offs between antipredator behaviours and foraging are well suited to manipulation in laboratory and field settings and have generated a vast compendium of knowledge. However, much less is known about how animals manage trade-offs between predation risk and pursuit of reproductive opportunities in the absence of the confounding effects of foraging. In the present study, we investigated how the nonfeeding migratory life stage of sea lamprey, Petromyzon marinus, responds to odour from dead conspecifics (a cue that induces avoidance behaviours in laboratory and field studies). We released groups of PIT-tagged sea lamprey 65 m from the shore of Lake Michigan or 287 m upstream in Carp Lake River and used antennas to detect their movements in the river. As the breeding season progressed, sea lamprey initiated upstream movement earlier and were more likely to enter the river. Sea lamprey that began the night in Lake Michigan entered Carp Lake River at higher rates and accelerated upstream when exposed to high concentrations of alarm cue, consistent with animals attempting to minimize time spent in risky areas. Sea lampreys that began the night in the river delayed upstream movement when exposed to alarm cue, consistent with animals sheltering and gathering information about a source of risk. We attribute this context-specific reaction to alarm cue to differences in perceived vulnerability to predation in sheltered positions in the river versus exposed positions in the lake. Once in the river, the vast majority of sea lamprey moved upstream independent of alarm cue or Julian date. Although life-history-induced time and energy budgets place rigid constraints on the direction of migration, sea lamprey attend to predation risk by modifying movement timing and speed.

  8. Fuzzy efficiency optimization of AC induction motors

    NASA Technical Reports Server (NTRS)

    Jani, Yashvant; Sousa, Gilberto; Turner, Wayne; Spiegel, Ron; Chappell, Jeff

    1993-01-01

    This paper describes the early states of work to implement a fuzzy logic controller to optimize the efficiency of AC induction motor/adjustable speed drive (ASD) systems running at less than optimal speed and torque conditions. In this paper, the process by which the membership functions of the controller were tuned is discussed and a controller which operates on frequency as well as voltage is proposed. The membership functions for this dual-variable controller are sketched. Additional topics include an approach for fuzzy logic to motor current control which can be used with vector-controlled drives. Incorporation of a fuzzy controller as an application-specific integrated circuit (ASIC) microchip is planned.

  9. Vehicle speed control device

    SciTech Connect

    Thornton-Trump, W.E.

    1987-03-10

    An apparatus is described for automatically limiting the speed of a vehicle powered by an internal combustion engine having a spark ignition system with an ignition coil, comprising: sensor means for generating a speed signal directly representative of the speed of the vehicle comprising a series of speed signal pulses having a pulse repetition frequency proportional to the speed of the vehicle; control means for converting speed signal pulses into a DC voltage proportional to the vehicle speed; means for comparing the DC voltage to a predetermined DC voltage having substantially zero AC components representative of a predetermined maximum speed and for generating a difference signal in response thereto; and means for generating a pulse-width modulated control signal responsive to the difference signal; power means responsive to the control signal for intermittently interrupting the ignition system.

  10. Design of a Sub-Picosecond Jitter with Adjustable-Range CMOS Delay-Locked Loop for High-Speed and Low-Power Applications.

    PubMed

    Abdulrazzaq, Bilal I; Ibrahim, Omar J; Kawahito, Shoji; Sidek, Roslina M; Shafie, Suhaidi; Yunus, Nurul Amziah Md; Lee, Lini; Halin, Izhal Abdul

    2016-09-28

    A Delay-Locked Loop (DLL) with a modified charge pump circuit is proposed for generating high-resolution linear delay steps with sub-picosecond jitter performance and adjustable delay range. The small-signal model of the modified charge pump circuit is analyzed to bring forth the relationship between the DLL's internal control voltage and output time delay. Circuit post-layout simulation shows that a 0.97 ps delay step within a 69 ps delay range with 0.26 ps Root-Mean Square (RMS) jitter performance is achievable using a standard 0.13 µm Complementary Metal-Oxide Semiconductor (CMOS) process. The post-layout simulation results show that the power consumption of the proposed DLL architecture's circuit is 0.1 mW when the DLL is operated at 2 GHz.

  11. Design of a Sub-Picosecond Jitter with Adjustable-Range CMOS Delay-Locked Loop for High-Speed and Low-Power Applications

    PubMed Central

    Abdulrazzaq, Bilal I.; Ibrahim, Omar J.; Kawahito, Shoji; Sidek, Roslina M.; Shafie, Suhaidi; Yunus, Nurul Amziah Md.; Lee, Lini; Halin, Izhal Abdul

    2016-01-01

    A Delay-Locked Loop (DLL) with a modified charge pump circuit is proposed for generating high-resolution linear delay steps with sub-picosecond jitter performance and adjustable delay range. The small-signal model of the modified charge pump circuit is analyzed to bring forth the relationship between the DLL’s internal control voltage and output time delay. Circuit post-layout simulation shows that a 0.97 ps delay step within a 69 ps delay range with 0.26 ps Root-Mean Square (RMS) jitter performance is achievable using a standard 0.13 µm Complementary Metal-Oxide Semiconductor (CMOS) process. The post-layout simulation results show that the power consumption of the proposed DLL architecture’s circuit is 0.1 mW when the DLL is operated at 2 GHz. PMID:27690040

  12. Speed control for synchronous motors

    NASA Technical Reports Server (NTRS)

    Packard, H.; Schott, J.

    1981-01-01

    Feedback circuit controls fluctuations in speed of synchronous ac motor. Voltage proportional to phase angle is developed by phase detector, rectified, amplified, compared to threshold, and reapplied positively or negatively to motor excitation circuit. Speed control reduces wow and flutter of audio turntables and tape recorders, and enhances hunting in gyroscope motors.

  13. Chiropractic Adjustment

    MedlinePlus

    ... structural alignment and improve your body's physical function. Low back pain, neck pain and headache are the most common ... treated. Chiropractic adjustment can be effective in treating low back pain, although much of the research done shows only ...

  14. Adjustment disorder

    MedlinePlus

    ... from other people Skipped heartbeats and other physical complaints Trembling or twitching To have adjustment disorder, you ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  15. Installation considerations for IGBT AC drives

    SciTech Connect

    Skibinski, G.L.

    1997-06-01

    In the last four years, Adjustable Speed ac Drive (ASD) manufacturers have migrated from Bipolar Junction Transistor (BJT) semiconductors to Insulated Gate Bipolar Transistors (IGBTs) as the preferred Output switching device. The advantage of IGBTs over BJTs is that device rise and fall time switching capability is 5 - 10 times faster, resulting in lower device switching loss and a more efficient drive. However, for a similar motor cable length as the BJT drive, the faster output voltage risetime of the IGBT drive may increase the dielectric voltage stress on the motor and cable due to a phenomenon called reflected wave. Faster output dv/dt transitions of IGBT drives also increase the possibility for phenomenon such as increased Common Mode (CM) electrical noise, Electromagnetic Interference (EMI) problems and increased capacitive cable charging current problems. Also, recent experience suggests any Pulse Width Modulated (PWM) drive with a steep fronted output voltage wave form may increase motor shaft voltage and lead to a bearing current phenomenon known as fluting. This paper provides a basic understanding of these issues, as well as solutions, to insure a successful drive system installation.

  16. Shaft adjuster

    DOEpatents

    Harry, H.H.

    1988-03-11

    Abstract and method for the adjustment and alignment of shafts in high power devices. A plurality of adjacent rotatable angled cylinders are positioned between a base and the shaft to be aligned which when rotated introduce an axial offset. The apparatus is electrically conductive and constructed of a structurally rigid material. The angled cylinders allow the shaft such as the center conductor in a pulse line machine to be offset in any desired alignment position within the range of the apparatus. 3 figs.

  17. Shaft adjuster

    DOEpatents

    Harry, Herbert H.

    1989-01-01

    Apparatus and method for the adjustment and alignment of shafts in high power devices. A plurality of adjacent rotatable angled cylinders are positioned between a base and the shaft to be aligned which when rotated introduce an axial offset. The apparatus is electrically conductive and constructed of a structurally rigid material. The angled cylinders allow the shaft such as the center conductor in a pulse line machine to be offset in any desired alignment position within the range of the apparatus.

  18. 78 FR 19416 - Revisions to Patent Term Adjustment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-01

    ... United States Patent and Trademark Office 37 CFR Part 1 RIN 0651-AC84 Revisions to Patent Term Adjustment... changes to the patent term adjustment provisions in section 1(h) of the Act to correct and improve certain... patent term adjustment period is measured, and clarifies the date from which the three-year patent...

  19. Circuit Regulates Speed Of dc Motor

    NASA Technical Reports Server (NTRS)

    Weaver, Charles; Padden, Robin; Brown, Floyd A., Jr.

    1990-01-01

    Driving circuit regulates speed of small dc permanent-magnet motor in tape recorder. Two nested feedback loops maintain speed within 1 percent of constant value. Inner loop provides coarse regulation, while outer loop removes most of variation in speed that remains in the presence of regulation by the inner loop. Compares speed of motor with commanded speed and adjusts current supplied to motor accordingly.

  20. ACS: ALMA Common Software

    NASA Astrophysics Data System (ADS)

    Chiozzi, Gianluca; Šekoranja, Matej

    2013-02-01

    ALMA Common Software (ACS) provides a software infrastructure common to all ALMA partners and consists of a documented collection of common patterns and components which implement those patterns. The heart of ACS is based on a distributed Component-Container model, with ACS Components implemented as CORBA objects in any of the supported programming languages. ACS provides common CORBA-based services such as logging, error and alarm management, configuration database and lifecycle management. Although designed for ALMA, ACS can and is being used in other control systems and distributed software projects, since it implements proven design patterns using state of the art, reliable technology. It also allows, through the use of well-known standard constructs and components, that other team members whom are not authors of ACS easily understand the architecture of software modules, making maintenance affordable even on a very large project.

  1. Precision electronic speed controller for an alternating-current motor

    DOEpatents

    Bolie, V.W.

    A high precision controller for an alternating-current multi-phase electrical motor that is subject to a large inertial load. The controller was developed for controlling, in a neutron chopper system, a heavy spinning rotor that must be rotated in phase-locked synchronism with a reference pulse train that is representative of an ac power supply signal having a meandering line frequency. The controller includes a shaft revolution sensor which provides a feedback pulse train representative of the actual speed of the motor. An internal digital timing signal generator provides a reference signal which is compared with the feedback signal in a computing unit to provide a motor control signal. The motor control signal is a weighted linear sum of a speed error voltage, a phase error voltage, and a drift error voltage, each of which is computed anew with each revolution of the motor shaft. The speed error signal is generated by a novel vernier-logic circuit which is drift-free and highly sensitive to small speed changes. The phase error is also computed by digital logic, with adjustable sensitivity around a 0 mid-scale value. The drift error signal, generated by long-term counting of the phase error, is used to compensate for any slow changes in the average friction drag on the motor. An auxillary drift-byte status sensor prevents any disruptive overflow or underflow of the drift-error counter. An adjustable clocked-delay unit is inserted between the controller and the source of the reference pulse train to permit phase alignment of the rotor to any desired offset angle. The stator windings of the motor are driven by two amplifiers which are provided with input signals having the proper quadrature relationship by an exciter unit consisting of a voltage controlled oscillator, a binary counter, a pair of read-only memories, and a pair of digital-to-analog converters.

  2. Simultaneous dimension reduction and adjustment for confounding variation.

    PubMed

    Lin, Zhixiang; Yang, Can; Zhu, Ying; Duchi, John; Fu, Yao; Wang, Yong; Jiang, Bai; Zamanighomi, Mahdi; Xu, Xuming; Li, Mingfeng; Sestan, Nenad; Zhao, Hongyu; Wong, Wing Hung

    2016-12-20

    Dimension reduction methods are commonly applied to high-throughput biological datasets. However, the results can be hindered by confounding factors, either biological or technical in origin. In this study, we extend principal component analysis (PCA) to propose AC-PCA for simultaneous dimension reduction and adjustment for confounding (AC) variation. We show that AC-PCA can adjust for (i) variations across individual donors present in a human brain exon array dataset and (ii) variations of different species in a model organism ENCODE RNA sequencing dataset. Our approach is able to recover the anatomical structure of neocortical regions and to capture the shared variation among species during embryonic development. For gene selection purposes, we extend AC-PCA with sparsity constraints and propose and implement an efficient algorithm. The methods developed in this paper can also be applied to more general settings. The R package and MATLAB source code are available at https://github.com/linzx06/AC-PCA.

  3. Power Electronic Transformer based Three-Phase PWM AC Drives

    NASA Astrophysics Data System (ADS)

    Basu, Kaushik

    A Transformer is used to provide galvanic isolation and to connect systems at different voltage levels. It is one of the largest and most expensive component in most of the high voltage and high power systems. Its size is inversely proportional to the operating frequency. The central idea behind a power electronic transformer (PET) also known as solid state transformer is to reduce the size of the transformer by increasing the frequency. Power electronic converters are used to change the frequency of operation. Steady reduction in the cost of the semiconductor switches and the advent of advanced magnetic materials with very low loss density and high saturation flux density implies economic viability and feasibility of a design with high power density. Application of PET is in generation of power from renewable energy sources, especially wind and solar. Other important application include grid tied inverters, UPS e.t.c. In this thesis non-resonant, single stage, bi-directional PET is considered. The main objective of this converter is to generate adjustable speed and magnitude pulse width modulated (PWM) ac waveforms from an ac or dc grid with a high frequency ac link. The windings of a high frequency transformer contains leakage inductance. Any switching transition of the power electronic converter connecting the inductive load and the transformer requires commutation of leakage energy. Commutation by passive means results in power loss, decrease in the frequency of operation, distortion in the output voltage waveform, reduction in reliability and power density. In this work a source based partially loss-less commutation of leakage energy has been proposed. This technique also results in partial soft-switching. A series of converters with novel PWM strategies have been proposed to minimize the frequency of leakage inductance commutation. These PETs achieve most of the important features of modern PWM ac drives including 1) Input power factor correction, 2) Common

  4. Adjustment of adaptive sum comb filter for PPG signals.

    PubMed

    Pilt, Kristjan; Meigas, Kalju; Ferenets, Rain; Kaik, Juri

    2009-01-01

    AC component of photoplethysmography signal carries important information for diagnostics. Registered signal may be affected by noises, which are sharing the same bandwidth. Adaptive comb filter is used for the AC component extraction. Due to filter averaging behavior it decreases the signal shape difference between consecutive beats. Comb filter needs to be adjusted for PPG signal. Comb filter new weight values are determined through numerical computation. Experiments with generated photoplethysmographic signals were carried out to compare adjusted and non-adjusted adaptive sum comb filter.

  5. Microfabricated AC impedance sensor

    DOEpatents

    Krulevitch, Peter; Ackler, Harold D.; Becker, Frederick; Boser, Bernhard E.; Eldredge, Adam B.; Fuller, Christopher K.; Gascoyne, Peter R. C.; Hamilton, Julie K.; Swierkowski, Stefan P.; Wang, Xiao-Bo

    2002-01-01

    A microfabricated instrument for detecting and identifying cells and other particles based on alternating current (AC) impedance measurements. The microfabricated AC impedance sensor includes two critical elements: 1) a microfluidic chip, preferably of glass substrates, having at least one microchannel therein and with electrodes patterned on both substrates, and 2) electrical circuits that connect to the electrodes on the microfluidic chip and detect signals associated with particles traveling down the microchannels. These circuits enable multiple AC impedance measurements of individual particles at high throughput rates with sufficient resolution to identify different particle and cell types as appropriate for environmental detection and clinical diagnostic applications.

  6. Voight variable speed drive. [for windpowered generator

    NASA Technical Reports Server (NTRS)

    Tompkin, J.

    1973-01-01

    The variable speed drive transmission is mounted within the gondola and connected with the wind turbine blades and the hub. This unit is designed for the production of ac power. The turbine turns by means of the variable speed drive and a set of synchronous three phase generators. This motion is controlled automatically by two wind rosettes in such a way that the wind turbine always opposes the wind direction. The Voight variable speed drive is a mechanical variable positive drive gear transmission. It has an unlimited power and torque transmission, a constant ratio with high degree of accuracy, a speed variation over a wide range, and a nonslip drive.

  7. AC magnetohydrodynamic microfluidic switch

    SciTech Connect

    Lemoff, A V; Lee, A P

    2000-03-02

    A microfluidic switch has been demonstrated using an AC Magnetohydrodynamic (MHD) pumping mechanism in which the Lorentz force is used to pump an electrolytic solution. By integrating two AC MHD pumps into different arms of a Y-shaped fluidic circuit, flow can be switched between the two arms. This type of switch can be used to produce complex fluidic routing, which may have multiple applications in {micro}TAS.

  8. Tevatron AC dipole system

    SciTech Connect

    Miyamoto, R.; Kopp, S.E.; Jansson, A.; Syphers, M.J.; /Fermilab

    2007-06-01

    The AC dipole is an oscillating dipole magnet which can induce large amplitude oscillations without the emittance growth and decoherence. These properties make it a good tool to measure optics of a hadron synchrotron. The vertical AC dipole for the Tevatron is powered by an inexpensive high power audio amplifier since its operating frequency is approximately 20 kHz. The magnet is incorporated into a parallel resonant system to maximize the current. The use of a vertical pinger magnet which has been installed in the Tevatron made the cost relatively inexpensive. Recently, the initial system was upgraded with a more powerful amplifier and oscillation amplitudes up to 2-3{sigma} were achieved with the 980 GeV proton beam. This paper discusses details of the Tevatron AC dipole system and also shows its test results.

  9. On-Chip AC self-test controller

    DOEpatents

    Flanagan, John D.; Herring, Jay R.; Lo, Tin-Chee

    2009-09-29

    A system for performing AC self-test on an integrated circuit that includes a system clock for normal operation is provided. The system includes the system clock, self-test circuitry, a first and second test register to capture and launch test data in response to a sequence of data pulses, and a logic circuit to be tested. The self-test circuitry includes an AC self-test controller and a clock splitter. The clock splitter generates the sequence of data pulses including a long data capture pulse followed by an at speed data launch pulse and an at speed data capture pulse followed by a long data launch pulse. The at speed data launch pulse and the at speed data capture pulse are generated for a common cycle of the system clock.

  10. ACS CCDs daily monitor

    NASA Astrophysics Data System (ADS)

    Sirianni, Marco

    2006-07-01

    This program consists of a set of basic tests to monitor, the read noise, thedevelopment of hot pixels and test for any source of noise in ACS CCDdetectors. The files, biases and dark will be used to create referencefiles for science calibration. This programme will be for the entire lifetime of ACS.For cycle 15 the program will cover 18 months 12.1.06->05.31.08and it has been divied into three different proposal each covering six months.The three poroposal are 11041-11042-11043.

  11. ac bidirectional motor controller

    NASA Technical Reports Server (NTRS)

    Schreiner, K.

    1988-01-01

    Test data are presented and the design of a high-efficiency motor/generator controller at NASA-Lewis for use with the Space Station power system testbed is described. The bidirectional motor driver is a 20 kHz to variable frequency three-phase ac converter that operates from the high-frequency ac bus being designed for the Space Station. A zero-voltage-switching pulse-density-modulation technique is used in the converter to shape the low-frequency output waveform.

  12. Development of a hardware-based AC microgrid for AC stability assessment

    NASA Astrophysics Data System (ADS)

    Swanson, Robert R.

    As more power electronic-based devices enable the development of high-bandwidth AC microgrids, the topic of microgrid power distribution stability has become of increased interest. Recently, researchers have proposed a relatively straightforward method to assess the stability of AC systems based upon the time-constants of sources, the net bus capacitance, and the rate limits of sources. In this research, a focus has been to develop a hardware test system to evaluate AC system stability. As a first step, a time domain model of a two converter microgrid was established in which a three phase inverter acts as a power source and an active rectifier serves as an adjustable constant power AC load. The constant power load can be utilized to create rapid power flow transients to the generating system. As a second step, the inverter and active rectifier were designed using a Smart Power Module IGBT for switching and an embedded microcontroller as a processor for algorithm implementation. The inverter and active rectifier were designed to operate simultaneously using a synchronization signal to ensure each respective local controller operates in a common reference frame. Finally, the physical system was created and initial testing performed to validate the hardware functionality as a variable amplitude and variable frequency AC system.

  13. Variable-speed, portable routing skate

    NASA Technical Reports Server (NTRS)

    Pesch, W. A.

    1967-01-01

    Lightweight, portable, variable-speed routing skate is used on heavy metal subassemblies which are impractical to move to a stationary machine. The assembly, consisting of the housing with rollers, router, and driving mechanism with transmission, weighs about forty pounds. Both speed and depth of cut are adjustable.

  14. 77 FR 49354 - Revision of Patent Term Adjustment Provisions Relating to Appellate Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-16

    ... Patent and Trademark Office 37 CFR Part 1 RIN 0651-AC63 Revision of Patent Term Adjustment Provisions... adjustment provisions of the rules of practice in patent cases to better reflect the period of appellate review. The patent term adjustment provisions of the American Inventors Protection Act of 1999...

  15. AC/DC converter

    NASA Astrophysics Data System (ADS)

    Jain, Praveen K.

    1992-08-01

    In a system such as a 20 kHz space station primary electrical power distribution system, power conversion from AC to DC is required. Some of the basic requirements for this conversion are high efficiency, light weight and small volume, regulated output voltage, close to unity input power factor, distortionless input current, soft-starting, low electromagnetic interference, and high reliability. An AC-to-DC converter is disclosed which satisfies the main design objectives of such converters for use in space. The converter of the invention comprises an input transformer, a resonant network, a current controller, a diode rectifier, and an output filter. The input transformer is for connection to a single phase, high frequency, sinusoidal waveform AC voltage source and provides a matching voltage isolating from the AC source. The resonant network converts this voltage to a sinusoidal, high frequency bidirectional current output, which is received by the current controller to provide the desired output current. The diode rectifier is connected in parallel with the current controller to convert the bidirectional current into a unidirectional current output. The output filter is connected to the rectifier to provide an essentially ripple-free, substantially constant voltage DC output.

  16. AC/RF Superconductivity

    SciTech Connect

    Ciovati, Gianluigi

    2015-02-01

    This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field dependence of the surface resistance, and the superheating field.

  17. High speed multiphoton imaging

    NASA Astrophysics Data System (ADS)

    Li, Yongxiao; Brustle, Anne; Gautam, Vini; Cockburn, Ian; Gillespie, Cathy; Gaus, Katharina; Lee, Woei Ming

    2016-12-01

    Intravital multiphoton microscopy has emerged as a powerful technique to visualize cellular processes in-vivo. Real time processes revealed through live imaging provided many opportunities to capture cellular activities in living animals. The typical parameters that determine the performance of multiphoton microscopy are speed, field of view, 3D imaging and imaging depth; many of these are important to achieving data from in-vivo. Here, we provide a full exposition of the flexible polygon mirror based high speed laser scanning multiphoton imaging system, PCI-6110 card (National Instruments) and high speed analog frame grabber card (Matrox Solios eA/XA), which allows for rapid adjustments between frame rates i.e. 5 Hz to 50 Hz with 512 × 512 pixels. Furthermore, a motion correction algorithm is also used to mitigate motion artifacts. A customized control software called Pscan 1.0 is developed for the system. This is then followed by calibration of the imaging performance of the system and a series of quantitative in-vitro and in-vivo imaging in neuronal tissues and mice.

  18. New levitation scheme with AC superconducting magnet for EDS MAGLEV system

    SciTech Connect

    Kim, D.H.; Lee, J.K.; Hahn, S.Y.; Cha, G.

    1996-09-01

    This paper proposes a new magnetic levitation scheme which is able to generate levitation force for all speeds including a standstill. Auxiliary wheels which are needed in EDS MAGLEV vehicle can be eliminated. This scheme uses AC superconducting magnets to generate levitation force. In this paper, magnetic fields, forces and power dissipations generated by AC magnets moving above a conducting slab are calculated analytically. Results of calculation show characteristics of EDS system with AC magnet, such as levitation force and loss, are superior to those of EDS system with DC magnets for all speeds.

  19. AC propulsion system for an electric vehicle, phase 2

    NASA Technical Reports Server (NTRS)

    Slicker, J. M.

    1983-01-01

    A second-generation prototype ac propulsion system for a passenger electric vehicle was designed, fabricated, tested, installed in a modified Mercury Lynx vehicle and track tested at the Contractor's site. The system consisted of a Phase 2, 18.7 kw rated ac induction traction motor, a 192-volt, battery powered, pulse-width-modulated, transistorized inverter packaged for under rear seat installation, a 2-axis, 2-speed, automatically-shifted mechanical transaxle and a microprocessor-based powertrain/vehicle controller. A diagnostics computer to assist tuning and fault finding was fabricated. Dc-to-mechanical-system efficiency varied from 78% to 82% as axle speed/torque ranged from 159 rpm/788 nm to 65 rpm/328 nm. Track test efficiency results suggest that the ac system will be equal or superior to dc systems when driving urban cycles. Additional short-term work is being performed under a third contract phase (AC-3) to raise transaxle efficiency to predicted levels, and to improve starting and shifting characteristics. However, the long-term challenge to the system's viability remains inverter cost. A final report on the Phase 2 system, describing Phase 3 modifications, will be issued at the conclusion of AC-3.

  20. The ac propulsion system for an electric vehicle, phase 1

    NASA Technical Reports Server (NTRS)

    Geppert, S.

    1981-01-01

    A functional prototype of an electric vehicle ac propulsion system was built consisting of a 18.65 kW rated ac induction traction motor, pulse width modulated (PWM) transistorized inverter, two speed mechanically shifted automatic transmission, and an overall drive/vehicle controller. Design developmental steps, and test results of individual components and the complex system on an instrumented test frame are described. Computer models were developed for the inverter, motor and a representative vehicle. A preliminary reliability model and failure modes effects analysis are given.

  1. AC resistance measuring instrument

    DOEpatents

    Hof, P.J.

    1983-10-04

    An auto-ranging AC resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an AC excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance. After the auto-ranging and auto-compensation functions are complete, the microprocessor calculates the resistance of the load from the selected range resistance, the excitation signal, and the load voltage signal, and displays of the measured resistance on a digital display of the instrument. 8 figs.

  2. AC Resistance measuring instrument

    DOEpatents

    Hof, Peter J.

    1983-01-01

    An auto-ranging AC resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an AC excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance. After the auto-ranging and auto-compensation functions are complete, the microprocessor calculates the resistance of the load from the selected range resistance, the excitation signal, and the load voltage signal, and displays of the measured resistance on a digital display of the instrument.

  3. AC Optimal Power Flow

    SciTech Connect

    2016-10-04

    In this work, we have implemented and developed the simulation software to implement the mathematical model of an AC Optimal Power Flow (OPF) problem. The objective function is to minimize the total cost of generation subject to constraints of node power balance (both real and reactive) and line power flow limits (MW, MVAr, and MVA). We have currently implemented the polar coordinate version of the problem. In the present work, we have used the optimization solver, Knitro (proprietary and not included in this software) to solve the problem and we have kept option for both the native numerical derivative evaluation (working satisfactorily now) as well as for analytical formulas corresponding to the derivatives being provided to Knitro (currently, in the debugging stage). Since the AC OPF is a highly non-convex optimization problem, we have also kept the option for a multistart solution. All of these can be decided by the user during run-time in an interactive manner. The software has been developed in C++ programming language, running with GCC compiler on a Linux machine. We have tested for satisfactory results against Matpower for the IEEE 14 bus system.

  4. Identification of /sup 233/Ac

    SciTech Connect

    Chu, Y.Y.; Zhou, M.L.

    1983-09-01

    We report in this paper identification of the new isotope /sup 233/Ac. Uranium targets were irradiated with 28 GeV protons; after rapid retrieval of the target and separation of actinium from thorium, /sup 233/Ac was allowed to decay into the known /sup 233/Th daughter. Exhaustive chemical purification was employed to permit the identification of /sup 233/Th via its characteristic ..gamma.. radiations. The half-life derived for /sup 233/Ac from several experiments is 2.3 +- 0.3 min. The production cross section for /sup 233/Ac is 100 ..mu..b.

  5. Digital ac monitor

    DOEpatents

    Hart, George W.; Kern, Jr., Edward C.

    1987-06-09

    An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer.

  6. Digital ac monitor

    DOEpatents

    Hart, G.W.; Kern, E.C. Jr.

    1987-06-09

    An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer. 24 figs.

  7. Cooling Floor AC Systems

    NASA Astrophysics Data System (ADS)

    Jun, Lu; Hao, Ding; Hong, Zhang; Ce, Gao Dian

    The present HVAC equipments for the residential buildings in the Hot-summer-and-Cold-winter climate region are still at a high energy consuming level. So that the high efficiency HVAC system is an urgently need for achieving the preset government energy saving goal. With its advantage of highly sanitary, highly comfortable and uniform of temperature field, the hot-water resource floor radiation heating system has been widely accepted. This paper has put forward a new way in air-conditioning, which combines the fresh-air supply unit and such floor radiation system for the dehumidification and cooling in summer or heating in winter. By analyze its advantages and limitations, we found that this so called Cooling/ Heating Floor AC System can improve the IAQ of residential building while keep high efficiency quality. We also recommend a methodology for the HVAC system designing, which will ensure the reduction of energy cost of users.

  8. Spatial layout affects speed discrimination

    NASA Technical Reports Server (NTRS)

    Verghese, P.; Stone, L. S.

    1997-01-01

    We address a surprising result in a previous study of speed discrimination with multiple moving gratings: discrimination thresholds decreased when the number of stimuli was increased, but remained unchanged when the area of a single stimulus was increased [Verghese & Stone (1995). Vision Research, 35, 2811-2823]. In this study, we manipulated the spatial- and phase relationship between multiple grating patches to determine their effect on speed discrimination thresholds. In a fusion experiment, we merged multiple stimulus patches, in stages, into a single patch. Thresholds increased as the patches were brought closer and their phase relationship was adjusted to be consistent with a single patch. Thresholds increased further still as these patches were fused into a single patch. In a fission experiment, we divided a single large patch into multiple patches by superimposing a cross with luminance equal to that of the background. Thresholds decreased as the large patch was divided into quadrants and decreased further as the quadrants were maximally separated. However, when the cross luminance was darker than the background, it was perceived as an occluder and thresholds, on average, were unchanged from that for the single large patch. A control experiment shows that the observed trend in discrimination thresholds is not due to the differences in perceived speed of the stimuli. These results suggest that the parsing of the visual image into entities affects the combination of speed information across space, and that each discrete entity effectively provides a single independent estimate of speed.

  9. Automated ac galvanomagnetic measurement system

    NASA Technical Reports Server (NTRS)

    Szofran, F. R.; Espy, P. N.

    1985-01-01

    An automated, ac galvanomagnetic measurement system is described. Hall or van der Pauw measurements in the temperature range 10-300 K can be made at a preselected magnetic field without operator attendance. Procedures to validate sample installation and correct operation of other system functions, such as magnetic field and thermometry, are included. Advantages of ac measurements are discussed.

  10. 78 FR 24336 - Rules of Practice and Procedure; Adjusting Civil Money Penalties for Inflation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-25

    ... 12 CFR Part 622 RIN 3052-AC87 Rules of Practice and Procedure; Adjusting Civil Money Penalties for... inflation adjustments to civil money penalties (CMPs) that the Farm Credit Administration (FCA) may impose... civil money penalties by the rate of inflation under the Federal Civil Penalties Inflation...

  11. Remotely Adjustable Hydraulic Pump

    NASA Technical Reports Server (NTRS)

    Kouns, H. H.; Gardner, L. D.

    1987-01-01

    Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

  12. Adjustable Pitot Probe

    NASA Technical Reports Server (NTRS)

    Ashby, George C., Jr.; Robbins, W. Eugene; Horsley, Lewis A.

    1991-01-01

    Probe readily positionable in core of uniform flow in hypersonic wind tunnel. Formed of pair of mating cylindrical housings: transducer housing and pitot-tube housing. Pitot tube supported by adjustable wedge fairing attached to top of pitot-tube housing with semicircular foot. Probe adjusted both radially and circumferentially. In addition, pressure-sensing transducer cooled internally by water or other cooling fluid passing through annulus of cooling system.

  13. Implementation of Temperature Sequential Controller on Variable Speed Drive

    NASA Astrophysics Data System (ADS)

    Cheong, Z. X.; Barsoum, N. N.

    2008-10-01

    There are many pump and motor installations with quite extensive speed variation, such as Sago conveyor, heating, ventilation and air conditioning (HVAC) and water pumping system. A common solution for these applications is to run several fixed speed motors in parallel, with flow control accomplish by turning the motors on and off. This type of control method causes high in-rush current, and adds a risk of damage caused by pressure transients. This paper explains the design and implementation of a temperature speed control system for use in industrial and commercial sectors. Advanced temperature speed control can be achieved by using ABB ACS800 variable speed drive-direct torque sequential control macro, programmable logic controller and temperature transmitter. The principle of direct torque sequential control macro (DTC-SC) is based on the control of torque and flux utilizing the stator flux field orientation over seven preset constant speed. As a result of continuous comparison of ambient temperature to the references temperatures; electromagnetic torque response is particularly fast to the motor state and it is able maintain constant speeds. Experimental tests have been carried out by using ABB ACS800-U1-0003-2, to validate the effectiveness and dynamic respond of ABB ACS800 against temperature variation, loads, and mechanical shocks.

  14. Weighted triangulation adjustment

    USGS Publications Warehouse

    Anderson, Walter L.

    1969-01-01

    The variation of coordinates method is employed to perform a weighted least squares adjustment of horizontal survey networks. Geodetic coordinates are required for each fixed and adjustable station. A preliminary inverse geodetic position computation is made for each observed line. Weights associated with each observed equation for direction, azimuth, and distance are applied in the formation of the normal equations in-the least squares adjustment. The number of normal equations that may be solved is twice the number of new stations and less than 150. When the normal equations are solved, shifts are produced at adjustable stations. Previously computed correction factors are applied to the shifts and a most probable geodetic position is found for each adjustable station. Pinal azimuths and distances are computed. These may be written onto magnetic tape for subsequent computation of state plane or grid coordinates. Input consists of punch cards containing project identification, program options, and position and observation information. Results listed include preliminary and final positions, residuals, observation equations, solution of the normal equations showing magnitudes of shifts, and a plot of each adjusted and fixed station. During processing, data sets containing irrecoverable errors are rejected and the type of error is listed. The computer resumes processing of additional data sets.. Other conditions cause warning-errors to be issued, and processing continues with the current data set.

  15. Ac Synchronous Servo Based On The Armature Voltage Prediction Model

    NASA Astrophysics Data System (ADS)

    Hoshino, Akihiro; Kuromaru, Hiroshi; Kobayashi, Shinichi

    1987-10-01

    A new control method of the AC synchro-nous servo-system (Brushless DC servo-system) is discussed. The new system is based on the armature voltage prediction model. Without a resolver-digital-conver-ter nor a tachometer-generator, the resolver provides following three signals to the system immediately, they are the current command, the induced voltage, and the rotor speed. The new method realizes a simple hardware configuration. Experimental results show a good performance of the system.

  16. Layoff Handling Still Lags ACS Standards.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1981

    1981-01-01

    Reviews termination procedures of professional chemists and the compliance of these terminations to the American Chemical Society's (ACS's) Professional Employment Guidelines. Provides the ACS guidelines. (DS)

  17. Demonstration of an ac Josephson junction laser

    NASA Astrophysics Data System (ADS)

    Cassidy, M. C.; Bruno, A.; Rubbert, S.; Irfan, M.; Kammhuber, J.; Schouten, R. N.; Akhmerov, A. R.; Kouwenhoven, L. P.

    2017-03-01

    Superconducting electronic devices have reemerged as contenders for both classical and quantum computing due to their fast operation speeds, low dissipation, and long coherence times. An ultimate demonstration of coherence is lasing. We use one of the fundamental aspects of superconductivity, the ac Josephson effect, to demonstrate a laser made from a Josephson junction strongly coupled to a multimode superconducting cavity. A dc voltage bias applied across the junction provides a source of microwave photons, and the circuit’s nonlinearity allows for efficient down-conversion of higher-order Josephson frequencies to the cavity’s fundamental mode. The simple fabrication and operation allows for easy integration with a range of quantum devices, allowing for efficient on-chip generation of coherent microwave photons at low temperatures.

  18. Advanced ac powertrain for electric vehicles

    SciTech Connect

    Slicker, J.M.; Kalns, L.

    1985-01-01

    The design of an ac propulsion system for an electric vehicle includes a three-phase induction motor, transistorized PWM inverter/battery charger, microprocessor-based controller, and two-speed automatic transaxle. This system was built and installed in a Mercury Lynx test bed vehicle as part of a Department of Energy propulsion system development program. An integral part of the inverter is a 4-kw battery charger which utilizes one of the bridge transistors. The overall inverter strategy for this configuration is discussed. The function of the microprocessor-based controller is described. Typical test results of the total vehicle and each of its major components are given, including system efficiencies and test track performance results.

  19. AC photovoltaic module magnetic fields

    SciTech Connect

    Jennings, C.; Chang, G.J.; Reyes, A.B.; Whitaker, C.M.

    1997-12-31

    Implementation of alternating current (AC) photovoltaic (PV) modules, particularly for distributed applications such as PV rooftops and facades, may be slowed by public concern about electric and magnetic fields (EMF). This paper documents magnetic field measurements on an AC PV module, complementing EMF research on direct-current PV modules conducted by PG and E in 1993. Although not comprehensive, the PV EMF data indicate that 60 Hz magnetic fields (the EMF type of greatest public concern) from PV modules are comparable to, or significantly less than, those from household appliances. Given the present EMF research knowledge, AC PV module EMF may not merit considerable concern.

  20. Adjustment of automatic control systems of production facilities at coal processing plants using multivariant physico- mathematical models

    NASA Astrophysics Data System (ADS)

    Evtushenko, V. F.; Myshlyaev, L. P.; Makarov, G. V.; Ivushkin, K. A.; Burkova, E. V.

    2016-10-01

    The structure of multi-variant physical and mathematical models of control system is offered as well as its application for adjustment of automatic control system (ACS) of production facilities on the example of coal processing plant.

  1. Recirculating valve lash adjuster

    SciTech Connect

    Stoody, R.R.

    1987-02-24

    This patent describes an internal combustion engine with a valve assembly of the type including overhead valves supported by a cylinder head for opening and closing movements in a substantially vertical direction and a rotatable overhead camshaft thereabove lubricated by engine oil pumped by an engine oil pump. A hydraulic lash adjuster with an internal reservoir therein is solely supplied with run-off lubricating oil from the camshaft which oil is pumped into the internal reservoir of the lash adjuster by self-pumping operation of the lash adjuster produced by lateral forces thereon by the rotative operation of the camshaft comprising: a housing of the lash adjuster including an axially extending bore therethrough with a lower wall means of the housing closing the lower end thereof; a first plunger member being closely slidably received in the bore of the housing and having wall means defining a fluid filled power chamber with the lower wall means of the housing; and a second plunger member of the lash adjuster having a portion being loosely slidably received and extending into the bore of the housing for reciprocation therein. Another portion extends upwardly from the housing to operatively receive alternating side-to-side force inputs from operation of the camshaft.

  2. Apparent speed increases at low luminance

    PubMed Central

    Vaziri-Pashkam, Maryam; Cavanagh, Patrick

    2009-01-01

    To investigate the effect of luminance on apparent speed, subjects adjusted the speed of a low-luminance rotating grating (0.31 cd/m2) to match that of a high-luminance one (1260 cd/m2). Above 4 Hz, subjects overestimated the speed of the low-luminance grating. This overestimation increased as a function of temporal rate and reached 30% around 10 Hz temporal rates. The speed overestimation became significant once the lower luminance was 2.4 log units lower than the high luminance comparison. Next the role of motion smear in speed overestimation was examined. First it was shown that the length of the perceived motion smear increased at low luminances. Second, the length of the visible smear was manipulated by changing the presentation time of the stimuli. Speed overestimation was reduced at shorter presentation times. Third the speed of a blurred stimulus was compared to a stimulus with sharp edges and the blurred stimulus was judged to move faster. These results indicate that the length of motion smear following a target contributes to its perceived speed and that this leads to speed overestimation at low luminance where motion traces lengthen because of increased persistence. PMID:19146275

  3. Methods, systems and apparatus for controlling operation of two alternating current (AC) machines

    DOEpatents

    Gallegos-Lopez, Gabriel [Torrance, CA; Nagashima, James M [Cerritos, CA; Perisic, Milun [Torrance, CA; Hiti, Silva [Redondo Beach, CA

    2012-06-05

    A system is provided for controlling two alternating current (AC) machines via a five-phase PWM inverter module. The system comprises a first control loop, a second control loop, and a current command adjustment module. The current command adjustment module operates in conjunction with the first control loop and the second control loop to continuously adjust current command signals that control the first AC machine and the second AC machine such that they share the input voltage available to them without compromising the target mechanical output power of either machine. This way, even when the phase voltage available to either one of the machines decreases, that machine outputs its target mechanical output power.

  4. Capping risk adjustment?

    PubMed

    Eugster, Patrick; Sennhauser, Michèle; Zweifel, Peter

    2010-07-01

    When premiums are community-rated, risk adjustment (RA) serves to mitigate competitive insurers' incentive to select favorable risks. However, unless fully prospective, it also undermines their incentives for efficiency. By capping its volume, one may try to counteract this tendency, exposing insurers to some financial risk. This in term runs counter the quest to refine the RA formula, which would increase RA volume. Specifically, the adjuster, "Hospitalization or living in a nursing home during the previous year" will be added in Switzerland starting 2012. This paper investigates how to minimize the opportunity cost of capping RA in terms of increased incentives for risk selection.

  5. ACS after SM4: On-orbit Verification of the HST Advanced Camera for Surveys Repair

    NASA Astrophysics Data System (ADS)

    Golimowski, David A.; Cheng, E. S.; Loose, M.; Sirianni, M.; Lupie, O. L.; Smith, L. J.; Arslanian, S.; Boyce, K. R.; Chapman, G.; Chiaberge, M.; Desjardins, T.; Dye, D.; Ellis, T.; Grogin, N. A.; Lim, P.; Lucas, R. A.; Maybhate, A.; Mil, K. J.; Mutchler, M.; Ricardo, R.; Scott, B.; Serrano, B.; Suchkov, A.; Waczynski, A.; Welty, A. D.; Wheeler, T.; Wilson, E.

    2010-01-01

    The newly replaced CCD electronics box (CEB-R) of the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) features a programmable SIDECAR ASIC manufactured by Teledyne. The CEB-R not only restores the functionality of the ACS Wide Field Camera (WFC), but it allows optimization of the WFC's imaging performance via on-orbit adjustment of CCD bias and clock voltages and serial-data transmission timing. We describe the strategy, preparation, execution, and results of the ACS Optimization Campaign, an unprecedented on-orbit extension of ground-based integration and testing that was conducted during the HST Servicing Mission Observatory Verification period.

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

    NASA Technical Reports Server (NTRS)

    Peak, S. C.

    1982-01-01

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

  7. Psychological Adjustment and Homosexuality.

    ERIC Educational Resources Information Center

    Gonsiorek, John C.

    In this paper, the diverse literature bearing on the topic of homosexuality and psychological adjustment is critically reviewed and synthesized. The first chapter discusses the most crucial methodological issue in this area, the problem of sampling. The kinds of samples used to date are critically examined, and some suggestions for improved…

  8. Self Adjusting Sunglasses

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Corning Glass Works' Serengeti Driver sunglasses are unique in that their lenses self-adjust and filter light while suppressing glare. They eliminate more than 99% of the ultraviolet rays in sunlight. The frames are based on the NASA Anthropometric Source Book.

  9. Self adjusting inclinometer

    DOEpatents

    Hunter, Steven L.

    2002-01-01

    An inclinometer utilizing synchronous demodulation for high resolution and electronic offset adjustment provides a wide dynamic range without any moving components. A device encompassing a tiltmeter and accompanying electronic circuitry provides quasi-leveled tilt sensors that detect highly resolved tilt change without signal saturation.

  10. Neural Mechanisms of Speed-Accuracy Tradeoff

    PubMed Central

    Heitz, Richard P.; Schall, Jeffrey D.

    2012-01-01

    SUMMARY Intelligent agents balance speed of responding with accuracy of deciding. Stochastic accumulator models commonly explain this speed-accuracy tradeoff by strategic adjustment of response threshold. Several laboratories identify specific neurons in prefrontal and parietal cortex with this accumulation process, yet no neurophysiological correlates of speed-accuracy tradeoff have been described. We trained macaque monkeys to trade speed for accuracy on cue during visual search and recorded the activity of neurons in the frontal eye field. Unpredicted by any model, we discovered that speed-accuracy tradeoff is accomplished through several distinct adjustments. Visually responsive neurons modulated baseline firing rate, sensory gain, and the duration of perceptual processing. Movement neurons triggered responses with activity modulated in a direction opposite of model predictions. Thus, current stochastic accumulator models provide an incomplete description of the neural processes accomplishing speed-accuracy tradeoffs. The diversity of neural mechanisms was reconciled with the accumulator framework through an integrated accumulator model constrained by requirements of the motor system. PMID:23141072

  11. Kinematic synthesis of adjustable robotic mechanisms

    NASA Astrophysics Data System (ADS)

    Chuenchom, Thatchai

    1993-01-01

    Conventional hard automation, such as a linkage-based or a cam-driven system, provides high speed capability and repeatability but not the flexibility required in many industrial applications. The conventional mechanisms, that are typically single-degree-of-freedom systems, are being increasingly replaced by multi-degree-of-freedom multi-actuators driven by logic controllers. Although this new trend in sophistication provides greatly enhanced flexibility, there are many instances where the flexibility needs are exaggerated and the associated complexity is unnecessary. Traditional mechanism-based hard automation, on the other hand, neither can fulfill multi-task requirements nor are cost-effective mainly due to lack of methods and tools to design-in flexibility. This dissertation attempts to bridge this technological gap by developing Adjustable Robotic Mechanisms (ARM's) or 'programmable mechanisms' as a middle ground between high speed hard automation and expensive serial jointed-arm robots. This research introduces the concept of adjustable robotic mechanisms towards cost-effective manufacturing automation. A generalized analytical synthesis technique has been developed to support the computational design of ARM's that lays the theoretical foundation for synthesis of adjustable mechanisms. The synthesis method developed in this dissertation, called generalized adjustable dyad and triad synthesis, advances the well-known Burmester theory in kinematics to a new level. While this method provides planar solutions, a novel patented scheme is utilized for converting prescribed three-dimensional motion specifications into sets of planar projections. This provides an analytical and a computational tool for designing adjustable mechanisms that satisfy multiple sets of three-dimensional motion specifications. Several design issues were addressed, including adjustable parameter identification, branching defect, and mechanical errors. An efficient mathematical scheme for

  12. Modelling ac ripple currents in HTS coated conductors

    NASA Astrophysics Data System (ADS)

    Xu, Zhihan; Grilli, Francesco

    2015-10-01

    Dc transmission using high temperature superconducting (HTS) coated conductors (CCs) offers a promising solution to the globally growing demand for effective, reliable and economic transmission of green energy up to the gigawatt level over very long distances. The credible estimation of the losses and thereby the heat dissipation involved, where ac ripples (introduced in rectification/ac-dc conversion) are viewed as a potential source of notable contribution, is highly essential for the rational design of practical HTS dc transmission cables and corresponding cryogenic systems to fulfil this demand. Here we report a targeted modelling study into the ac losses in a HTS CC subject to dc and ac ripple currents simultaneously, by solving Maxwell’s equations using the finite element method (FEM) in the commercial software package COMSOL. It is observed that the instantaneous loss exhibits only one peak per cycle in the HTS CC subject to sinusoidal ripples, given that the amplitude of the ac ripples is smaller than approximately 20% of that of the dc current. This is a distinct contrast to the usual observation of two peaks per cycle in a HTS CC subject to ac currents only. The unique mechanism is also revealed, which is directly associated with the finding that, around any local minima of the applied ac ripples, the critical state of -J c is never reached at the edges of the HTS CC, as it should be according to the Bean model. When running further into the longer term, it is discovered that the ac ripple loss of the HTS CC in full-wave rectification decays monotonically, at a speed which is found to be insensitive to the frequency of the applied ripples within our targeted situations, to a relatively low level of approximately 1.38 × 10-4 W m-1 in around 1.7 s. Comparison between this level and other typical loss contributions in a HTS dc cable implies that ac ripple currents in HTS CCs should only be considered as a minor source of dissipation in superconducting dc

  13. Aircraft Speed Instruments

    NASA Technical Reports Server (NTRS)

    Beij, K Hilding

    1933-01-01

    This report presents a concise survey of the measurement of air speed and ground speed on board aircraft. Special attention is paid to the pitot-static air-speed meter which is the standard in the United States for airplanes. Air-speed meters of the rotating vane type are also discussed in considerable detail on account of their value as flight test instruments and as service instruments for airships. Methods of ground-speed measurement are treated briefly, with reference to the more important instruments. A bibliography on air-speed measurement concludes the report.

  14. NONLINEAR DIAGNOSTICS USING AC DIPOLES.

    SciTech Connect

    PEGGS,S.

    1999-03-29

    There are three goals in the accurate nonlinear diagnosis of a storage ring. First, the beam must be moved to amplitudes many times the natural beam size. Second, strong and long lasting signals must be generated. Third, the measurement technique should be non-destructive. Conventionally, a single turn kick moves the beam to large amplitudes, and turn-by-turn data are recorded from multiple beam position monitors (BPMs) [1-6]. Unfortunately, tune spread across the beam causes the center of charge beam signal to ''decohere'' on a time scale often less than 100 turns. Filamentation also permanently destroys the beam emittance (in a hadron ring). Thus, the ''strong single turn kick'' technique successfully achieves only one out of the three goals. AC dipole techniques can achieve all three. Adiabatically excited AC dipoles slowly move the beam out to large amplitudes. The coherent signals then recorded last arbitrarily long. The beam maintains its original emittance if the AC dipoles are also turned off adiabatically, ready for further use. The AGS already uses an RF dipole to accelerate polarized proton beams through depolarizing resonances with minimal polarization loss [7]. Similar AC dipoles will be installed in the horizontal and vertical planes of both rings in RHIC [8]. The RHIC AC dipoles will also be used as spin flippers, and to measure linear optical functions [9].

  15. Exploration adjustment by ant colonies

    PubMed Central

    2016-01-01

    How do animals in groups organize their work? Division of labour, i.e. the process by which individuals within a group choose which tasks to perform, has been extensively studied in social insects. Variability among individuals within a colony seems to underpin both the decision over which tasks to perform and the amount of effort to invest in a task. Studies have focused mainly on discrete tasks, i.e. tasks with a recognizable end. Here, we study the distribution of effort in nest seeking, in the absence of new nest sites. Hence, this task is open-ended and individuals have to decide when to stop searching, even though the task has not been completed. We show that collective search effort declines when colonies inhabit better homes, as a consequence of a reduction in the number of bouts (exploratory events). Furthermore, we show an increase in bout exploration time and a decrease in bout instantaneous speed for colonies inhabiting better homes. The effect of treatment on bout effort is very small; however, we suggest that the organization of work performed within nest searching is achieved both by a process of self-selection of the most hard-working ants and individual effort adjustment. PMID:26909180

  16. Adjustable Autonomy Testbed

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Schrenkenghost, Debra K.

    2001-01-01

    The Adjustable Autonomy Testbed (AAT) is a simulation-based testbed located in the Intelligent Systems Laboratory in the Automation, Robotics and Simulation Division at NASA Johnson Space Center. The purpose of the testbed is to support evaluation and validation of prototypes of adjustable autonomous agent software for control and fault management for complex systems. The AA T project has developed prototype adjustable autonomous agent software and human interfaces for cooperative fault management. This software builds on current autonomous agent technology by altering the architecture, components and interfaces for effective teamwork between autonomous systems and human experts. Autonomous agents include a planner, flexible executive, low level control and deductive model-based fault isolation. Adjustable autonomy is intended to increase the flexibility and effectiveness of fault management with an autonomous system. The test domain for this work is control of advanced life support systems for habitats for planetary exploration. The CONFIG hybrid discrete event simulation environment provides flexible and dynamically reconfigurable models of the behavior of components and fluids in the life support systems. Both discrete event and continuous (discrete time) simulation are supported, and flows and pressures are computed globally. This provides fast dynamic simulations of interacting hardware systems in closed loops that can be reconfigured during operations scenarios, producing complex cascading effects of operations and failures. Current object-oriented model libraries support modeling of fluid systems, and models have been developed of physico-chemical and biological subsystems for processing advanced life support gases. In FY01, water recovery system models will be developed.

  17. Precision adjustable stage

    DOEpatents

    Cutburth, Ronald W.; Silva, Leonard L.

    1988-01-01

    An improved mounting stage of the type used for the detection of laser beams is disclosed. A stage center block is mounted on each of two opposite sides by a pair of spaced ball bearing tracks which provide stability as well as simplicity. The use of the spaced ball bearing pairs in conjunction with an adjustment screw which also provides support eliminates extraneous stabilization components and permits maximization of the area of the center block laser transmission hole.

  18. System and method for motor speed estimation of an electric motor

    DOEpatents

    Lu, Bin [Kenosha, WI; Yan, Ting [Brookfield, WI; Luebke, Charles John [Sussex, WI; Sharma, Santosh Kumar [Viman Nagar, IN

    2012-06-19

    A system and method for a motor management system includes a computer readable storage medium and a processing unit. The processing unit configured to determine a voltage value of a voltage input to an alternating current (AC) motor, determine a frequency value of at least one of a voltage input and a current input to the AC motor, determine a load value from the AC motor, and access a set of motor nameplate data, where the set of motor nameplate data includes a rated power, a rated speed, a rated frequency, and a rated voltage of the AC motor. The processing unit is also configured to estimate a motor speed based on the voltage value, the frequency value, the load value, and the set of nameplate data and also store the motor speed on the computer readable storage medium.

  19. Method and system for controlling a rotational speed of a rotor of a turbogenerator

    DOEpatents

    Stahlhut, Ronnie Dean; Vuk, Carl Thomas

    2008-12-30

    A system and method controls a rotational speed of a rotor or shaft of a turbogenerator in accordance with a present voltage level on a direct current bus. A lower threshold and a higher threshold are established for a speed of a rotor or shaft of a turbogenerator. A speed sensor determines speed data or a speed signal for the rotor or shaft associated with a turbogenerator. A voltage regulator adjusts a voltage level associated with a direct current bus within a target voltage range if the speed data or speed signal indicates that the speed is above the higher threshold or below the lower threshold.

  20. Residential Proximity to Major Roadways is Associated with Increased Levels of AC133+ Circulating Angiogenic Cells

    PubMed Central

    DeJarnett, Natasha; Yeager, Ray; Conklin, Daniel J.; Lee, Jongmin; O'Toole, Timothy E.; McCracken, James; Abplanalp, Wes; Srivastava, Sanjay; Riggs, Daniel W.; Hamzeh, Ihab; Wagner, Stephen; Chugh, Atul; DeFilippis, Andrew; Ciszewski, Tiffany; Wyatt, Brad; Becher, Carrie; Higdon, Deirdre; Ramos, Kenneth S.; Tollerud, David J.; Myers, John A.; Rai, Shesh N.; Shah, Jasmit; Zafar, Nagma; Krishnasamy, Sathya S.; Prabhu, Sumanth D.; Bhatnagar, Aruni

    2016-01-01

    Objective Previous studies have shown that residential proximity to a roadway is associated with increased cardiovascular disease (CVD) risk. Yet the nature of this association remains unclear, and its impact on individual CVD risk factors has not been assessed. The objective of this study was to determine whether residential proximity to roadways influences systemic inflammation and the levels of circulating angiogenic cells. Approach and Results In a cross-sectional study, CVD risk factors, blood levels of C-reactive protein (CRP), and 15 antigenically-defined circulating angiogenic cell populations were measured in participants (n=316) with moderate to high CVD risk. Attributes of roadways surrounding residential locations were assessed using Geographic Information Systems. Associations between road proximity and cardiovascular indices were analyzed using Generalized Linear Models. Close proximity (<50m) to a major roadway was associated with lower income and higher rates of smoking, but not CRP levels. After adjustment for potential confounders, levels of circulating angiogenic cell in peripheral blood were significantly elevated in people living in close proximity to a major roadway (CD31+/AC133+, AC133+, CD34+/AC133+, and CD34+/45dim/AC133+ cells); and positively associated with road segment distance (CD31+/AC133+, AC133+, and CD34+/AC133+ cells), traffic intensity (CD31+/AC133+ and AC133+ cells), and distance-weighted traffic intensity (CD31+/34+/45+/AC133+ cells). Conclusions Living close to a major roadway is associated with elevated levels of circulating cells positive for the “early” stem marker, AC133+. This may reflect an increased need for vascular repair. Levels of these cells in peripheral blood may be a sensitive index of cardiovascular injury due to residential proximity to roadways. PMID:26293462

  1. Scheme for rapid adjustment of network impedance

    DOEpatents

    Vithayathil, John J.

    1991-01-01

    A static controlled reactance device is inserted in series with an AC electric power transmission line to adjust its transfer impedance. An inductor (reactor) is serially connected with two back-to-back connected thyristors which control the conduction period and hence the effective reactance of the inductor. Additional reactive elements are provided in parallel with the thyristor controlled reactor to filter harmonics and to obtain required range of variable reactance. Alternatively, the static controlled reactance device discussed above may be connected to the secondary winding of a series transformer having its primary winding connected in series to the transmission line. In a three phase transmission system, the controlled reactance device may be connected in delta configuration on the secondary side of the series transformer to eliminate triplen harmonics.

  2. Speed limits of aircraft

    NASA Technical Reports Server (NTRS)

    Everling, E

    1923-01-01

    This paper is restricted to the question of attainable speed limits and attacks the problem from different angles. Theoretical limits due to air resistance are presented along with design factors which may affect speed such as wing loads, wing areas, wing section shifting, landing speeds, drag-lift ratios, and power coefficients.

  3. Adjustable Reeds For Weaving

    NASA Technical Reports Server (NTRS)

    Farley, Gary L.

    1994-01-01

    Local characteristics of fabrics varied to suit special applications. Adjustable reed machinery proposed for use in weaving fabrics in various net shapes, widths, yarn spacings, and yarn angles. Locations of edges of fabric and configuration of warp and filling yarns varied along fabric to obtain specified properties. In machinery, reed wires mounted in groups on sliders, mounted on lengthwise rails in reed frame. Mechanisms incorporated to move sliders lengthwise, parallel to warp yarns, by sliding them along rails; move sliders crosswise by translating reed frame rails perpendicular to warp yarns; and crosswise by spreading reed rails within group. Profile of reed wires in group on each slider changed.

  4. ACS from development to operations

    NASA Astrophysics Data System (ADS)

    Caproni, Alessandro; Colomer, Pau; Jeram, Bogdan; Sommer, Heiko; Chiozzi, Gianluca; Mañas, Miguel M.

    2016-08-01

    The ALMA Common Software (ACS), provides the infrastructure of the distributed software system of ALMA and other projects. ACS, built on top of CORBA and Data Distribution Service (DDS) middleware, is based on a Component- Container paradigm and hides the complexity of the middleware allowing the developer to focus on domain specific issues. The transition of the ALMA observatory from construction to operations brings with it that ACS effort focuses primarily on scalability, stability and robustness rather than on new features. The transition came together with a shorter release cycle and a more extensive testing. For scalability, the most problematic area has been the CORBA notification service, used to implement the publisher subscriber pattern because of the asynchronous nature of the paradigm: a lot of effort has been spent to improve its stability and recovery from run time errors. The original bulk data mechanism, implemented using the CORBA Audio/Video Streaming Service, showed its limitations and has been replaced with a more performant and scalable DDS implementation. Operational needs showed soon the difference between releases cycles for Online software (i.e. used during observations) and Offline software, which requires much more frequent releases. This paper attempts to describe the impact the transition from construction to operations had on ACS, the solution adopted so far and a look into future evolution.

  5. Simple Equipment for Imaging AC.

    ERIC Educational Resources Information Center

    Kamata, Masahiro; Anayama, Takayuki

    2003-01-01

    Presents an effective way to demonstrate the difference between direct current and alternating current using red and green LEDs. Describes how to make a tool that shows how an AC voltage changes with time using the afterimage effect of the LEDs. (Author/NB)

  6. Continuously adjustable Pulfrich spectacles

    NASA Astrophysics Data System (ADS)

    Jacobs, Ken; Karpf, Ron

    2011-03-01

    A number of Pulfrich 3-D movies and TV shows have been produced, but the standard implementation has inherent drawbacks. The movie and TV industries have correctly concluded that the standard Pulfrich 3-D implementation is not a useful 3-D technique. Continuously Adjustable Pulfrich Spectacles (CAPS) is a new implementation of the Pulfrich effect that allows any scene containing movement in a standard 2-D movie, which are most scenes, to be optionally viewed in 3-D using inexpensive viewing specs. Recent scientific results in the fields of human perception, optoelectronics, video compression and video format conversion are translated into a new implementation of Pulfrich 3- D. CAPS uses these results to continuously adjust to the movie so that the viewing spectacles always conform to the optical density that optimizes the Pulfrich stereoscopic illusion. CAPS instantly provides 3-D immersion to any moving scene in any 2-D movie. Without the glasses, the movie will appear as a normal 2-D image. CAPS work on any viewing device, and with any distribution medium. CAPS is appropriate for viewing Internet streamed movies in 3-D.

  7. Adjustable electronic load-alarm relay

    DOEpatents

    Mason, Charles H.; Sitton, Roy S.

    1976-01-01

    This invention is an improved electronic alarm relay for monitoring the current drawn by an AC motor or other electrical load. The circuit is designed to measure the load with high accuracy and to have excellent alarm repeatability. Chattering and arcing of the relay contacts are minimal. The operator can adjust the set point easily and can re-set both the high and the low alarm points by means of one simple adjustment. The relay includes means for generating a signal voltage proportional to the motor current. In a preferred form of the invention a first operational amplifier is provided to generate a first constant reference voltage which is higher than a preselected value of the signal voltage. A second operational amplifier is provided to generate a second constant reference voltage which is lower than the aforementioned preselected value of the signal voltage. A circuit comprising a first resistor serially connected to a second resistor is connected across the outputs of the first and second amplifiers, and the junction of the two resistors is connected to the inverting terminal of the second amplifier. Means are provided to compare the aforementioned signal voltage with both the first and second reference voltages and to actuate an alarm if the signal voltage is higher than the first reference voltage or lower than the second reference voltage.

  8. Adjustable hybrid diffractive/refractive achromatic lens

    PubMed Central

    Valley, Pouria; Savidis, Nickolaos; Schwiegerling, Jim; Dodge, Mohammad Reza; Peyman, Gholam; Peyghambarian, N.

    2011-01-01

    We demonstrate a variable focal length achromatic lens that consists of a flat liquid crystal diffractive lens and a pressure-controlled fluidic refractive lens. The diffractive lens is composed of a flat binary Fresnel zone structure and a thin liquid crystal layer, producing high efficiency and millisecond switching times while applying a low ac voltage input. The focusing power of the diffractive lens is adjusted by electrically modifying the sub-zones and re-establishing phase wrapping points. The refractive lens includes a fluid chamber with a flat glass surface and an opposing elastic polydimethylsiloxane (PDMS) membrane surface. Inserting fluid volume through a pump system into the clear aperture region alters the membrane curvature and adjusts the refractive lens’ focal position. Primary chromatic aberration is remarkably reduced through the coupling of the fluidic and diffractive lenses at selected focal lengths. Potential applications include miniature color imaging systems, medical and ophthalmic devices, or any design that utilizes variable focal length achromats. PMID:21503055

  9. A New High Speed Induction Motor Drive based on Field Orientation and Hysteresis Current Comparison

    NASA Astrophysics Data System (ADS)

    Ogbuka, Cosmas; Nwosu, Cajethan; Agu, Marcel

    2016-09-01

    This paper presents a new high speed induction motor drive based on the core advantage of field orientation control (FOC) and hysteresis current comparison (HCC). A complete closed loop speed-controlled induction motor drive system is developed consisting of an outer speed and an inner HCC algorithm which are optimised to obtain fast and stable speed response with effective current and torque tracking, both during transient and steady states. The developed model, being speed-controlled, was examined with step and ramp speed references and excellent performances obtained under full load stress. A speed response comparison of the model with the standard AC3 (Field-Oriented Control Induction Motor Drive) of MATLAB Simpower systems shows that the model achieved a rise time of 0.0762 seconds compared to 0.2930 seconds achieved by the AC3. Also, a settle time of 0.0775 seconds was obtained with the developed model while that of the AC3 model is 0.2986 seconds confirming, therefore, the superiority of the developed model over the AC3 model which, hitherto, served as a reference standard.

  10. High speed handpieces

    PubMed Central

    Bhandary, Nayan; Desai, Asavari; Shetty, Y Bharath

    2014-01-01

    High speed instruments are versatile instruments used by clinicians of all specialties of dentistry. It is important for clinicians to understand the types of high speed handpieces available and the mechanism of working. The centers for disease control and prevention have issued guidelines time and again for disinfection and sterilization of high speed handpieces. This article presents the recent developments in the design of the high speed handpieces. With a view to prevent hospital associated infections significant importance has been given to disinfection, sterilization & maintenance of high speed handpieces. How to cite the article: Bhandary N, Desai A, Shetty YB. High speed handpieces. J Int Oral Health 2014;6(1):130-2. PMID:24653618

  11. Data Capture Technique for High Speed Signaling

    DOEpatents

    Barrett, Wayne Melvin; Chen, Dong; Coteus, Paul William; Gara, Alan Gene; Jackson, Rory; Kopcsay, Gerard Vincent; Nathanson, Ben Jesse; Vranas, Paylos Michael; Takken, Todd E.

    2008-08-26

    A data capture technique for high speed signaling to allow for optimal sampling of an asynchronous data stream. This technique allows for extremely high data rates and does not require that a clock be sent with the data as is done in source synchronous systems. The present invention also provides a hardware mechanism for automatically adjusting transmission delays for optimal two-bit simultaneous bi-directional (SiBiDi) signaling.

  12. Nonintrusive shaft speed sensor

    NASA Technical Reports Server (NTRS)

    Barkhoudarian, S.; Wyett, L.; Maram, J.

    1985-01-01

    Reusable rocket engines such as the Space Shuttle Main Engines (SSME), the Orbital Transfer Vehicles (OTV), etc., have throttling capabilities that require real-time, closed-loop control systems of engine propellant flows, combustion temperatures and pressures, and turbopump rotary speeds. In the case of the SSME, there are four turbopumps that require real-time measurement and control of their rotary speeds. Variable-reluctance magnetic speed sensors were designed, fabricated, and tested for all four turbopumps, resulting in the successful implementation and operation of three of these speed sensors during each of the 12 Shuttle flights.

  13. ac-resistance-measuring instrument

    SciTech Connect

    Hof, P.J.

    1981-04-22

    An auto-ranging ac resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an ac excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance.

  14. Simultaneous distribution of AC and DC power

    DOEpatents

    Polese, Luigi Gentile

    2015-09-15

    A system and method for the transport and distribution of both AC (alternating current) power and DC (direct current) power over wiring infrastructure normally used for distributing AC power only, for example, residential and/or commercial buildings' electrical wires is disclosed and taught. The system and method permits the combining of AC and DC power sources and the simultaneous distribution of the resulting power over the same wiring. At the utilization site a complementary device permits the separation of the DC power from the AC power and their reconstruction, for use in conventional AC-only and DC-only devices.

  15. Delay Adjusted Incidence

    Cancer.gov

    This Infographic shows the National Cancer Institute SEER Incidence Trends. The graphs show the Average Annual Percent Change (AAPC) 2002-2011. For Men, Thyroid: 5.3*,Liver & IBD: 3.6*, Melanoma: 2.3*, Kidney: 2.0*, Myeloma: 1.9*, Pancreas: 1.2*, Leukemia: 0.9*, Oral Cavity: 0.5, Non-Hodgkin Lymphoma: 0.3*, Esophagus: -0.1, Brain & ONS: -0.2*, Bladder: -0.6*, All Sites: -1.1*, Stomach: -1.7*, Larynx: -1.9*, Prostate: -2.1*, Lung & Bronchus: -2.4*, and Colon & Rectum: -3/0*. For Women, Thyroid: 5.8*, Liver & IBD: 2.9*, Myeloma: 1.8*, Kidney: 1.6*, Melanoma: 1.5, Corpus & Uterus: 1.3*, Pancreas: 1.1*, Leukemia: 0.6*, Brain & ONS: 0, Non-Hodgkin Lymphoma: -0.1, All Sites: -0.1, Breast: -0.3, Stomach: -0.7*, Oral Cavity: -0.7*, Bladder: -0.9*, Ovary: -0.9*, Lung & Bronchus: -1.0*, Cervix: -2.4*, and Colon & Rectum: -2.7*. * AAPC is significantly different from zero (p<.05). Rates were adjusted for reporting delay in the registry. www.cancer.gov Source: Special section of the Annual Report to the Nation on the Status of Cancer, 1975-2011.

  16. Nonlinear Hydrostatic Adjustment.

    NASA Astrophysics Data System (ADS)

    Bannon, Peter R.

    1996-12-01

    The final equilibrium state of Lamb's hydrostatic adjustment problem is found for finite amplitude heating. Lamb's problem consists of the response of a compressible atmosphere to an instantaneous, horizontally homogeneous heating. Results are presented for both isothermal and nonisothermal atmospheres.As in the linear problem, the fluid displacements are confined to the heated layer and to the region aloft with no displacement of the fluid below the heating. The region above the heating is displaced uniformly upward for heating and downward for cooling. The amplitudes of the displacements are larger for cooling than for warming.Examination of the energetics reveals that the fraction of the heat deposited into the acoustic modes increases linearly with the amplitude of the heating. This fraction is typically small (e.g., 0.06% for a uniform warming of 1 K) and is essentially independent of the lapse rate of the base-state atmosphere. In contrast a fixed fraction of the available energy generated by the heating goes into the acoustic modes. This fraction (e.g., 12% for a standard tropospheric lapse rate) agrees with the linear result and increases with increasing stability of the base-state atmosphere.The compressible results are compared to solutions using various forms of the soundproof equations. None of the soundproof equations predict the finite amplitude solutions accurately. However, in the small amplitude limit, only the equations for deep convection advanced by Dutton and Fichtl predict the thermodynamic state variables accurately for a nonisothermal base-state atmosphere.

  17. Proactive Adjustments of Response Strategies in the Stop-Signal Paradigm

    ERIC Educational Resources Information Center

    Verbruggen, Frederick; Logan, Gordon D.

    2009-01-01

    In the stop-signal paradigm, fast responses are harder to inhibit than slow responses, so subjects must balance speed is the go task with successful stopping in the stop task. In theory, subjects achieve this balance by adjusting response thresholds for the go task, making proactive adjustments in response to instructions that indicate that…

  18. Shaft speed control

    NASA Technical Reports Server (NTRS)

    Ford, A. G.

    1979-01-01

    Simple mechanism controls rotation of heavy-duty shaft by mechanical comparison with rotation of small, precise, stepper motor. Mechanism can be used to limit winding and unwinding speeds of large spools and reels and to control speed of other rotating shafts. Setup incorporates reference shaft geared down from stepper motor and feedback shaft geared up from shaft to be controlled. Feedback and reference shafts are coupled with brake assembly inside stationary cylinder. When work shaft speeds up, brakes are activated automatically to slow it down.

  19. Negative hydrogen ion beam extraction from an AC heated cathode driven Bernas-type ion source

    NASA Astrophysics Data System (ADS)

    Okano, Y.; Miyamoto, N.; Kasuya, T.; Wada, M.

    2015-04-01

    A plasma grid structure was installed to a Bernas-type ion source used for ion implantation equipment. A negative hydrogen (H-) ion beam was extracted by an AC driven ion source by adjusting the bias to the plasma grid. The extracted electron current was reduced by positively biasing the plasma grid, while an optimum plasma grid bias voltage for negative ion beam extraction was found to be positive 3 V with respect to the arc chamber. Source operations with AC cathode heating show extraction characteristics almost identical to that with DC cathode heating, except a minute increase in H- current at higher frequency of cathode heating current.

  20. Effect of the magnetic material on AC losses in HTS conductors in AC magnetic field carrying AC transport current

    NASA Astrophysics Data System (ADS)

    Wan, Xing-Xing; Huang, Chen-Guang; Yong, Hua-Dong; Zhou, You-He

    2015-11-01

    This paper presents an investigation on the AC losses in several typical superconducting composite conductors using the H-formulation model. A single superconducting strip with ferromagnetic substrate or cores and a stack of coated conductors with ferromagnetic substrates are studied. We consider all the coated conductors carrying AC transport currents and simultaneously exposed to perpendicular AC magnetic fields. The influences of the amplitude, frequency, phase difference and ferromagnetic materials on the AC losses are investigated. The results show that the magnetization losses of single strip and stacked strips have similar characteristics. The ferromagnetic substrate can increase the magnetization loss at low magnetic field, and decrease the loss at high magnetic field. The ferromagnetic substrate can obviously increase the transport loss in stacked strips. The trends of total AC losses of single strip and stacked strips are similar when they are carrying current or exposed to a perpendicular magnetic field. The effect of the frequency on the total AC losses of single strip is related to the amplitude of magnetic field. The AC losses decrease with increasing frequency in low magnetic field region while increase in high magnetic field region. As the phase difference changes, there is a periodic variation for the AC losses. Moreover, when the strip is under only the transport current and magnetic field, the ferromagnetic cores will increase the AC losses for large transport current or field.

  1. Speeding earthquake disaster relief

    USGS Publications Warehouse

    Mortensen, Carl; Donlin, Carolyn; Page, Robert A.; Ward, Peter

    1995-01-01

    In coping with recent multibillion-dollar earthquake disasters, scientists and emergency managers have found new ways to speed and improve relief efforts. This progress is founded on the rapid availability of earthquake information from seismograph networks.

  2. Speed- Reading Made Easy

    ERIC Educational Resources Information Center

    Brown, W. S.

    1970-01-01

    Illustrates a compromise between vertical and horizontal typographies which should make speed reading faster and more reliable, and suggests that computers could prepare text according to this arrangement. (MB)

  3. High Speed Research Program

    NASA Technical Reports Server (NTRS)

    Anderson, Robert E.; Corsiglia, Victor R.; Schmitz, Frederic H. (Technical Monitor)

    1994-01-01

    An overview of the NASA High Speed Research Program will be presented from a NASA Headquarters perspective. The presentation will include the objectives of the program and an outline of major programmatic issues.

  4. High-Speed Photography

    SciTech Connect

    Paisley, D.L.; Schelev, M.Y.

    1998-08-01

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) {copyright} {ital 1998 Society of Photo-Optical Instrumentation Engineers.}

  5. Effective AC needleless and collectorless electrospinning for yarn production.

    PubMed

    Pokorny, P; Kostakova, E; Sanetrnik, F; Mikes, P; Chvojka, J; Kalous, T; Bilek, M; Pejchar, K; Valtera, J; Lukas, D

    2014-12-28

    Nanofibrous materials are essential components for a wide range of applications, particularly in the fields of medicine and material engineering. These include protective materials, sensors, cosmetics, hygiene, filtration and energy storage. The most widely used and researched technology in these fields is electrospinning. This method for producing fibers yields highly promising results thanks to its versatility and simplicity. Electrospinning is employed in multiple forms, among which needle and needleless direct current (DC) variants are the most distinctive. The former is based on the generation of just one single jet from a nozzle; hence this fabrication process is not very productive. The latter uses the destabilization of free liquid surfaces by means of an electric field, which enhances the throughput since it produces numerous jets, emitted from the surfaces of rollers, spheres, strings and spirals. However, although some progress in total producibility has been achieved, the efficiency of the DC method still remains relatively low. A further drawback of DC electrospinning is that both variants need a collector, which makes it difficult to combine DC electrospinning easily with other technologies due to the presence of the high field strength within the entire spinning zone. This paper describes our experiments with AC electrospinning. We show that alternating current (AC) electrospinning based on a needleless spinning-electrode provides a highly productive smoke-like aerogel composed of nanofibers. This aerogel rises rapidly from the electrode like a thin plume of smoke, without any need for a collector. Our work shows that AC needleless electrospinning gains its efficiency and collector-less feature thanks to the creation of a perpetually charge-changing virtual counter-electrode composed of the nanofibers emitted. High-speed camera recordings demonstrate the formation mechanism of the nanofibrous plume, which is wafted by an electric wind. This wind

  6. ac powertrain for an electric vehicle. Phase 2 and Phase 3 final report

    SciTech Connect

    Slicker, J.M.

    1984-11-01

    This report describes work relating to Phases 2 and 3 development and testing of an ac powertrain for a 25 hp four-passenger electric vehicle. The system, which consists of a two-speed automatic mechanical transaxle, 18.6 kW ac induction traction motor, 33.6 kW inverter and overall logic controller, was installed and evaluated in a converted Mercury Lynx rolling test bed vehicle. An on-board charger and an auxiliary dc-to-dc converter were integrated into the inverter/controller package.

  7. Compact change speed transmission

    SciTech Connect

    Iwanaga, K.; Yamaguchi, T.

    1989-06-06

    A change speed transmission is described comprising: a stationary part; an input member; an output member; first and second planetary gear sets; clutch and brake means for selectively controlling the first and second planetary gear sets to provide a plurality of forward speed rations and a reverse speed ratio between the input and output member; the clutch and brake means including a first clutch, a first one-way clutch, and a second one-way clutch which, when the first clutch is engaged, provide a path of transmission of reaction to the stationary part thereby establishing a path of transmission of torque through at least a part of the first and second planetary gear sets to achieve a predetermined one speed ratio of the forward speed ratios; the clutch and brake means including also a brake and a second slutch which, when both of the brake and the second clutch are engaged, hinder the action of the second one-way clutch and that of the first one-way clutch, respectively, thereby providing engine braking during running with the predetermined one speed ratio; the first clutch including means forming a drum-shaped member disposed radially outwardly of and receiving at least one of the first and second planetary gear sets, and an actuating piston of the first clutch; and the second clutch including an actuating piston slidably disposed within the actuating piston of the first clutch.

  8. [Risk perception and speeding].

    PubMed

    Thielen, Iara Picchioni; Hartmann, Ricardo Carlos; Soares, Diogo Picchioni

    2008-01-01

    This paper discusses risk perception comparing drivers with and without fines for speeding. The research aimed to show the interaction between speeding laws and speeding behavior. Speeders' explanations for their behavior revealed important factors in the determination of risk perception: control (driver-centered), risk minimization (drivers claimed there was no risk involved in the way they speeded), self-confidence (they considered themselves good drivers and believed they were able to define what constitutes speeding), and lack of credibility in the institutions that manage traffic risks. Speeders display a cognitive construct of personal invulnerability combined with unrealistic optimism and overrated self-perception, along with an exaggerated perception of their control over the traffic setting, centered on their self-purported driving skills. No difference was found in risk perception between drivers in the two groups. There was no relationship between objective and perceived risks, since drivers from the two groups showed a generic perception of objective risks, but out-of-context in relation to the inherent potential for accidents at different speeds.

  9. High Speed Ice Friction

    NASA Astrophysics Data System (ADS)

    Seymour-Pierce, Alexandra; Sammonds, Peter; Lishman, Ben

    2014-05-01

    Many different tribological experiments have been run to determine the frictional behaviour of ice at high speeds, ostensibly with the intention of applying results to everyday fields such as winter tyres and sports. However, experiments have only been conducted up to linear speeds of several metres a second, with few additional subject specific studies reaching speeds comparable to these applications. Experiments were conducted in the cold rooms of the Rock and Ice Physics Laboratory, UCL, on a custom built rotational tribometer based on previous literature designs. Preliminary results from experiments run at 2m/s for ice temperatures of 271 and 263K indicate that colder ice has a higher coefficient of friction, in accordance with the literature. These results will be presented, along with data from further experiments conducted at temperatures between 259-273K (in order to cover a wide range of the temperature dependent behaviour of ice) and speeds of 2-15m/s to produce a temperature-velocity-friction map for ice. The effect of temperature, speed and slider geometry on the deformation of ice will also be investigated. These speeds are approaching those exhibited by sports such as the luge (where athletes slide downhill on an icy track), placing the tribological work in context.

  10. Calculating Speed of Sound

    NASA Astrophysics Data System (ADS)

    Bhatnagar, Shalabh

    2017-01-01

    Sound is an emerging source of renewable energy but it has some limitations. The main limitation is, the amount of energy that can be extracted from sound is very less and that is because of the velocity of the sound. The velocity of sound changes as per medium. If we could increase the velocity of the sound in a medium we would be probably able to extract more amount of energy from sound and will be able to transfer it at a higher rate. To increase the velocity of sound we should know the speed of sound. If we go by the theory of classic mechanics speed is the distance travelled by a particle divided by time whereas velocity is the displacement of particle divided by time. The speed of sound in dry air at 20 °C (68 °F) is considered to be 343.2 meters per second and it won't be wrong in saying that 342.2 meters is the velocity of sound not the speed as it's the displacement of the sound not the total distance sound wave covered. Sound travels in the form of mechanical wave, so while calculating the speed of sound the whole path of wave should be considered not just the distance traveled by sound. In this paper I would like to focus on calculating the actual speed of sound wave which can help us to extract more energy and make sound travel with faster velocity.

  11. Spousal Adjustment to Myocardial Infarction.

    ERIC Educational Resources Information Center

    Ziglar, Elisa J.

    This paper reviews the literature on the stresses and coping strategies of spouses of patients with myocardial infarction (MI). It attempts to identify specific problem areas of adjustment for the spouse and to explore the effects of spousal adjustment on patient recovery. Chapter one provides an overview of the importance in examining the…

  12. 75 FR 25927 - Vehicle/Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-10

    ... Transportation Federal Railroad Administration 49 CFR Parts 213 and 238 Vehicle/Track Interaction Safety... Administration 49 CFR Parts 213 and 238 RIN 2130-AC09 Vehicle/Track Interaction Safety Standards; High-Speed and... Safety Standards and Passenger Equipment Safety Standards applicable to high-speed and high...

  13. ac electroosmosis in rectangular microchannels.

    PubMed

    Campisi, Michele; Accoto, Dino; Dario, Paolo

    2005-11-22

    Motivated by the growing interest in ac electroosmosis as a reliable no moving parts strategy to control fluid motion in microfluidic devices for biomedical applications, such as lab-on-a-chip, we study transient and steady-state electrokinetic phenomena (electroosmosis and streaming currents) in infinitely extended rectangular charged microchannels. With the aid of Fourier series and Laplace transforms we provide a general formal solution of the problem, which is used to study the time-dependent response to sudden ac applied voltage differences in case of finite electric double layer. The Debye-Huckel approximation has been adopted to allow for an algebraic solution of the Poisson-Boltzmann problem in Fourier space. We obtain the expressions of flow velocity profiles, flow rates, streaming currents, as well as expressions of the complex hydraulic and electrokinetic conductances. We analyze in detail the dependence of the electrokinetic conductance on the extension of linear dimensions relative to the Debye length, with an eye on finite electric double layer effects.

  14. ACS PSF Variations with Temperatures

    NASA Astrophysics Data System (ADS)

    Sahu, Kailash C.; Lallo, Matt; Makidon, Russ

    2007-09-01

    We have used the HST ACS/WFC observations of a Galactic bulge field taken over a continuous interval of 7 days (Prop 9750) to investigate the possible dependence of the ACS focus with the external temperatures. This dataset allows us to investigate possible focus variations over timescales of a few hours to a few days. The engineering data related to the external temperatures for this duration show that the maximum temperature change occurred over the first 1.5 days. Among all the different temperatures recorded, the truss diametric differential and the truss axial temperatures are the only two temperatures which have the same timescale of variation as the PSFwidth variations. The PSF-widths also strongly correlate with these two temperatures during this time interval. We empirically fit the PSF-width variations with these 2 temperature sensor values. This suggests that the focus has a similar dependence, and we recommend that this finding be followed up with the determination of actual focus values to check if the focus values indeed have the same correlation. If so, the temperature data can be useful in estimating the focus values, which can then be used to predict the PSFs to a first order.

  15. ac electroosmosis in rectangular microchannels

    NASA Astrophysics Data System (ADS)

    Campisi, Michele; Accoto, Dino; Dario, Paolo

    2005-11-01

    Motivated by the growing interest in ac electroosmosis as a reliable no moving parts strategy to control fluid motion in microfluidic devices for biomedical applications, such as lab-on-a-chip, we study transient and steady-state electrokinetic phenomena (electroosmosis and streaming currents) in infinitely extended rectangular charged microchannels. With the aid of Fourier series and Laplace transforms we provide a general formal solution of the problem, which is used to study the time-dependent response to sudden ac applied voltage differences in case of finite electric double layer. The Debye-Hückel approximation has been adopted to allow for an algebraic solution of the Poisson-Boltzmann problem in Fourier space. We obtain the expressions of flow velocity profiles, flow rates, streaming currents, as well as expressions of the complex hydraulic and electrokinetic conductances. We analyze in detail the dependence of the electrokinetic conductance on the extension of linear dimensions relative to the Debye length, with an eye on finite electric double layer effects.

  16. RHIC spin flipper AC dipole controller

    SciTech Connect

    Oddo, P.; Bai, M.; Dawson, C.; Gassner, D.; Harvey, M.; Hayes, T.; Mernick, K.; Minty, M.; Roser, T.; Severino, F.; Smith, K.

    2011-03-28

    The RHIC Spin Flipper's five high-Q AC dipoles which are driven by a swept frequency waveform require precise control of phase and amplitude during the sweep. This control is achieved using FPGA based feedback controllers. Multiple feedback loops are used to and dynamically tune the magnets. The current implementation and results will be presented. Work on a new spin flipper for RHIC (Relativistic Heavy Ion Collider) incorporating multiple dynamically tuned high-Q AC-dipoles has been developed for RHIC spin-physics experiments. A spin flipper is needed to cancel systematic errors by reversing the spin direction of the two colliding beams multiple times during a store. The spin flipper system consists of four DC-dipole magnets (spin rotators) and five AC-dipole magnets. Multiple AC-dipoles are needed to localize the driven coherent betatron oscillation inside the spin flipper. Operationally the AC-dipoles form two swept frequency bumps that minimize the effect of the AC-dipole dipoles outside of the spin flipper. Both AC bumps operate at the same frequency, but are phase shifted from each other. The AC-dipoles therefore require precise control over amplitude and phase making the implementation of the AC-dipole controller the central challenge.

  17. Design and develop speed/pressure regulator

    SciTech Connect

    Hasanul Basher, A.M.

    1993-09-01

    The Physics Division at Oak Ridge National Laboratory has several recirculating water cooling systems. One of them supplies deionized water at 150 psi, which is mainly used for cooling magnet windings at the Oak Ridge Isochronous Cyclotron (ORIC). The system has three 125-hp water pumps, each of which is capable of supplying water at the rate of 1000 gpm. One of the major requirements of this water supply system is that the supply pressure must be kept constant. An adjustable-frequency speed controller was recently installed to control the speed of one of the pump motors. A servo-system was provided with the adjustable-frequency controller for regulating motor speed and, subsequently, the water pressure. After unsuccessful attempts to operate the servo, it was concluded that the regulator may not work for the existing system. Prior to installation of the variable-frequency controller, pressure regulation was accomplished with a pneumatically controlled load by-pass valve. To maintain constant pressure in the system, it is necessary to run always at full load, even if full load is not on the system. Hence, there is a waste of energy when full load is not connected to the system. So, designing and implementing one regulator that works at any load condition has become necessary. This report discusses the design of such a pressure regulator.

  18. Speed Reading: Remember the Tortoise

    ERIC Educational Resources Information Center

    Graf, Richard G.

    1973-01-01

    After speed-reading partisans questioned the criticisms in a Psychology Today article, another psychologist conducted a controlled study of speed readers. As we said before, "Speed Readers Don't Read; They Skim". (Editor)

  19. Everyone Deserves a Speeding Ticket.

    ERIC Educational Resources Information Center

    Burris, Harold

    1993-01-01

    Presents a first day physics activity having students determine the fine for a speeding ticket if the speeds considered include the earth's rotation and revolution speed, and the movement through the galaxy. (MDH)

  20. Engine control system having speed-based timing

    DOEpatents

    Willi, Martin L [Dunlap, IL; Fiveland, Scott B [Metamora, IL; Montgomery, David T [Edelstein, IL; Gong, Weidong [Dunlap, IL

    2012-02-14

    A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a controller in communication with the actuator. The controller is configured to receive a signal indicative of engine speed and compare the engine speed signal with a desired engine speed. The controller is also configured to selectively regulate the actuator to adjust a timing of the engine valve to control an amount of air/fuel mixture delivered to the cylinder based on the comparison.

  1. Adjustable Josephson Coupler for Transmon Qubit Measurement

    NASA Astrophysics Data System (ADS)

    Jeffrey, Evan

    2015-03-01

    Transmon qubits are measured via a dispersive interaction with a linear resonator. In order to be scalable this measurement must be fast, accurate, and not disrupt the state of the qubit. Speed is of particular importance in a scalable architecture with error correction as the measurement accounts for substantial portion of the cycle time and waiting time associated with measurement is a major source of decoherence. We have found that measurement speed and accuracy can be improved by driving the qubit beyond the critical photon number ncrit = Δ/4g by a factor of 2-3 without compromising the QND nature of the measurement. While it is expected that such strong drive will cause qubit state transitions, we find that as long as the readout is sufficiently fast, those transitions are negligible, however they grow rapidly with time, and are not described by a simple rate. Measuring in this regime requires parametric amplifiers with very high saturation power, on the order of -105 dBm in order to avoid losing SNR when increasing the power. It also requires a Purcell filter to allow fast ring-up and ring-down. Adjustable couplers can be used to further increase the measurement performance, by switching the dispersive interaction on and off much faster than the cavity ring-down time. This technique can also be used to investigate the dynamics of the qubit cavity interaction beyond the weak dispersive limit ncavity >=ncrit not easily accessible to standard dispersive measurement due to the cavity time constant.

  2. Nonintrusive shaft speed sensor

    NASA Astrophysics Data System (ADS)

    Barkhoudarian, S.; Wyett, L.

    1985-04-01

    A computerized literature search on nonintrusive/noncontacting speed sensing technologies was performed, resulting in 550 abstracts and 42 articles. Fourteen techniques were identified and theoretically analyzed, resulting in the recommendation of the Microwave, Infrared, and Magnetic technologies for experimental evaluation. Test results with a novel magnetic approach, consisting of a permanent magnet placed on the rotating shaft and a pickup coil placed on the housing, indicated detection of a strong signal from 3.5 inches at the lowest required speed (600 rpm), through a 1.75-inch thick Inconel plate. Test results with microwave and infrared speed sensing approaches indicated transmission of sufficient microwave and infrared energy for detection even through heavily bubble-laden water (15 percent cavitation). Although all three techniques demonstrated feasibility, the magnetic sensor was recommended for preliminary design, which indicated no technical obstacles.

  3. Adjustable Induction-Heating Coil

    NASA Technical Reports Server (NTRS)

    Ellis, Rod; Bartolotta, Paul

    1990-01-01

    Improved design for induction-heating work coil facilitates optimization of heating in different metal specimens. Three segments adjusted independently to obtain desired distribution of temperature. Reduces time needed to achieve required temperature profiles.

  4. Effects of treadmill speed on the knee angle and stance time of white rats with knee osteoarthritis according to the treadmill speed

    PubMed Central

    Nam, Chan-Woo; Lee, Jung-Ho; Jang, Sang-Hun

    2016-01-01

    [Purpose] The purpose of this study was to identify whether walking on a treadmill at an adjusted speed is suitable for humans by examining the effects of exercise on the joint functions of white rats with induced knee osteoarthritis. [Subjects and Methods] The subjects were 20 Sprague-Dawley white rats, aged eight weeks, weighing 250 to 300 g. The moderate-speed exercise group performed their exercise at a gradient of 0% and a speed of 15 m/min, and the high-speed exercise group performed their exercise at a gradient of 0% and a speed of 26 m/min. [Results] Statistically significant changes were elicited by the moderate-speed and high-speed exercises. [Conclusion] In conclusion, the results of the present study present the importance of walking exercise. In particular, they demonstrate that changes in knee ROM and stance time are elicited by changes in walking speed. PMID:27942109

  5. The Measurement of the Speed of Light Using a Laser Pointer.

    ERIC Educational Resources Information Center

    Mak, Se-yuen; Yip, Din-yan

    2000-01-01

    Presents a method for measuring the speed of light using a laser pointer with adjustable focus as the signal carrier, a signal generator to modulate the light beam, and a student oscilloscope to detect the phase shift. (Author/CCM)

  6. Experimenting with End-Correction and the Speed of Sound

    ERIC Educational Resources Information Center

    LoPresto, Michael C.

    2011-01-01

    What follows is an alternative to the standard tuning fork and quarter-wave tube speed of sound experiment. Rather than adjusting the water level in a glass or plastic tube to vary the length of an air column, a set of resonance tubes of different lengths is used. The experiment still demonstrates the principles of standing waves in air columns…

  7. SPEEDE Made Easy.

    ERIC Educational Resources Information Center

    Palmer, Barbara H.; Wei, P. Betty

    1993-01-01

    A nontechnical overview of electronic data interchange (EDI) and of the SPEEDE/ExPRESS Project, which uses EDI to transmit transcripts between schools and colleges, is presented. It explores the fundamental value of the technology, specific costs and benefits, and its potential to transform the delivery of academic support services. (Author/MSE)

  8. High speed metal removal

    NASA Astrophysics Data System (ADS)

    Pugh, R. F.; Pohl, R. F.

    1982-10-01

    Four types of steel (AISI 1340, 4140, 4340, and HF-1) which are commonly used in large caliber projectile manufacture were machined at different hardness ranges representing the as-forged and the heat treated condition with various ceramic tools using ceramic coated tungsten carbide as a reference. Results show that machining speeds can be increased significantly using present available tooling.

  9. High speed door assembly

    DOEpatents

    Shapiro, Carolyn

    1993-01-01

    A high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  10. High speed door assembly

    DOEpatents

    Shapiro, C.

    1993-04-27

    A high speed door assembly is described, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  11. Transition at hypersonic speeds

    NASA Technical Reports Server (NTRS)

    Morkovin, Mark V.

    1987-01-01

    Certain conjectures on the physics of instabilities in high-speed flows are discussed and the state of knowledge of hypersonic transition summarized. The case is made for an unpressured systematic research program in this area consisting of controlled microscopic experiments, theory, and numerical simulations.

  12. AC Power Consumption of Single-Walled Carbon Nanotube Interconnects: Non-Equilibrium Green's Function Simulation

    NASA Astrophysics Data System (ADS)

    Yamamoto, Takahiro; Sasaoka, Kenji; Watanabe, Satoshi

    2012-04-01

    We theoretically investigate the emittance and dynamic dissipation of a nanoscale interconnect consisting of a metallic single-walled carbon nanotube using the non-equilibrium Green's function technique for AC electronic transport. We show that the emittance and dynamic dissipation depend strongly on the contact conditions of the interconnect and that the power consumption can be reduced by adjusting the contact conditions. We propose an appropriate condition of contact that yields a high power factor and low apparent power.

  13. High Speed Vortex Flows

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Wilcox, Floyd J., Jr.; Bauer, Steven X. S.; Allen, Jerry M.

    2000-01-01

    A review of the research conducted at the National Aeronautics and Space Administration (NASA), Langley Research Center (LaRC) into high-speed vortex flows during the 1970s, 1980s, and 1990s is presented. The data reviewed is for flat plates, cavities, bodies, missiles, wings, and aircraft. These data are presented and discussed relative to the design of future vehicles. Also presented is a brief historical review of the extensive body of high-speed vortex flow research from the 1940s to the present in order to provide perspective of the NASA LaRC's high-speed research results. Data are presented which show the types of vortex structures which occur at supersonic speeds and the impact of these flow structures to vehicle performance and control is discussed. The data presented shows the presence of both small- and large scale vortex structures for a variety of vehicles, from missiles to transports. For cavities, the data show very complex multiple vortex structures exist at all combinations of cavity depth to length ratios and Mach number. The data for missiles show the existence of very strong interference effects between body and/or fin vortices and the downstream fins. It was shown that these vortex flow interference effects could be both positive and negative. Data are shown which highlights the effect that leading-edge sweep, leading-edge bluntness, wing thickness, location of maximum thickness, and camber has on the aerodynamics of and flow over delta wings. The observed flow fields for delta wings (i.e. separation bubble, classical vortex, vortex with shock, etc.) are discussed in the context of' aircraft design. And data have been shown that indicate that aerodynamic performance improvements are available by considering vortex flows as a primary design feature. Finally a discussing of a design approach for wings which utilize vortex flows for improved aerodynamic performance at supersonic speed is presented.

  14. Method and system for an on-chip AC self-test controller

    DOEpatents

    Flanagan, John D.; Herring, Jay R.; Lo, Tin-Chee

    2006-06-06

    A method for performing AC self-test on an integrated circuit, including a system clock for use during normal operation. The method includes applying a long data capture pulse to a first test register in response to the system clock, and further applying at an speed data launch pulse to the first test register in response to the system clock. Inputting the data from the first register to a logic path in response to applying the at speed data launch pulse to the first test register. Applying at speed data capture pulse to a second test register in response to the system clock. Inputting the output from the logic path to the second test register in response to applying the at speed data capture pulse to the second register. Applying a long data launch pulse to the second test register in response to the system clock.

  15. Method and system for an on-chip AC self-test controller

    DOEpatents

    Flanagan, John D.; Herring, Jay R.; Lo, Tin-Chee

    2008-09-30

    A method and system for performing AC self-test on an integrated circuit that includes a system clock for use during normal operation are provided. The method includes applying a long data capture pulse to a first test register in response to the system clock, applying an at speed data launch pulse to the first test register in response to the system clock, inputting the data from the first register to a logic path in response to applying the at speed data launch pulse to the first test register, applying an at speed data capture pulse to a second test register in response to the system clock, inputting the logic path output to the second test register in response to applying the at speed data capture pulse to the second test register, and applying a long data launch pulse to the second test register in response to the system clock.

  16. Advanced AC permanent magnet axial flux disc motor for electric passenger vehicle

    NASA Technical Reports Server (NTRS)

    Kliman, G. B.

    1982-01-01

    An ac permanent magnet axial flux disc motor was developed to operate with a thyristor load commutated inverter as part of an electric vehicle drive system. The motor was required to deliver 29.8 kW (40 hp) peak and 10.4 kW (14 hp) average with a maximum speed of 11,000 rpm. It was also required to run at leading power factor to commutate the inverter. Three motors were built.

  17. AC impedance study of degradation of porous nickel battery electrodes

    NASA Technical Reports Server (NTRS)

    Lenhart, Stephen J.; Macdonald, D. D.; Pound, B. G.

    1987-01-01

    AC impedance spectra of porous nickel battery electrodes were recorded periodically during charge/discharge cycling in concentrated KOH solution at various temperatures. A transmission line model (TLM) was adopted to represent the impedance of the porous electrodes, and various model parameters were adjusted in a curve fitting routine to reproduce the experimental impedances. Degradation processes were deduced from changes in model parameters with electrode cycling time. In developing the TLM, impedance spectra of planar (nonporous) electrodes were used to represent the pore wall and backing plate interfacial impedances. These data were measured over a range of potentials and temperatures, and an equivalent circuit model was adopted to represent the planar electrode data. Cyclic voltammetry was used to study the characteristics of the oxygen evolution reaction on planar nickel electrodes during charging, since oxygen evolution can affect battery electrode charging efficiency and ultimately electrode cycle life if the overpotential for oxygen evolution is sufficiently low.

  18. Adjusting to Chronic Health Conditions.

    PubMed

    Helgeson, Vicki S; Zajdel, Melissa

    2017-01-03

    Research on adjustment to chronic disease is critical in today's world, in which people are living longer lives, but lives are increasingly likely to be characterized by one or more chronic illnesses. Chronic illnesses may deteriorate, enter remission, or fluctuate, but their defining characteristic is that they persist. In this review, we first examine the effects of chronic disease on one's sense of self. Then we review categories of factors that influence how one adjusts to chronic illness, with particular emphasis on the impact of these factors on functional status and psychosocial adjustment. We begin with contextual factors, including demographic variables such as sex and race, as well as illness dimensions such as stigma and illness identity. We then examine a set of dispositional factors that influence chronic illness adjustment, organizing these into resilience and vulnerability factors. Resilience factors include cognitive adaptation indicators, personality variables, and benefit-finding. Vulnerability factors include a pessimistic attributional style, negative gender-related traits, and rumination. We then turn to social environmental variables, including both supportive and unsupportive interactions. Finally, we review chronic illness adjustment within the context of dyadic coping. We conclude by examining potential interactions among these classes of variables and outlining a set of directions for future research.

  19. Perfecting the Photometric Calibration of the ACS CCD Cameras

    NASA Astrophysics Data System (ADS)

    Bohlin, Ralph C.

    2016-09-01

    Newly acquired data and improved data reduction algorithms mandate a fresh look at the absolute flux calibration of the charge-coupled device cameras on the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS). The goals are to achieve a 1% accuracy and to make this calibration more accessible to the HST guest investigator. Absolute fluxes from the CALSPEC1 database for three primary hot 30,000-60,000K WDs define the sensitivity calibrations for the Wide Field Channel (WFC) and High Resolution Channel (HRC) filters. The external uncertainty for the absolute flux is ˜1%, while the internal consistency of the sensitivities in the broadband ACS filters is ˜0.3% among the three primary WD flux standards. For stars as cool as K type, the agreement with the CALSPEC standards is within 1% at the WFC1-1K subarray position, which achieves the 1% precision goal for the first time. After making a small adjustment to the filter bandpass for F814W, the 1% precision goal is achieved over the full F814W WFC field of view for stars of K type and hotter. New encircled energies and absolute sensitivities replace the seminal results of Sirianni et al. that were published in 2005. After implementing the throughput updates, synthetic predictions of the WFC and HRC count rates for the average of the three primary WD standard stars agree with the observations to 0.1%.

  20. ACS after Servicing Mission 4: The WFC Optimization Campaign

    NASA Astrophysics Data System (ADS)

    Golimowski, David; Cheng, Ed; Loose, Markus; Sirianni, Marco; Lupie, Olivia; Smith, Linda; Arslanian, Steve; Boyce, Kevin; Chapman, George; Chiaberge, Marco; Desjardins, Tyler; Dye, Darryl; Grogin, Norman; Lim, Pey Lian; Lucas, Ray; Maybhate, Aparna; Mil, Kathleen; Mutchler, Max; Ricardo, Raphael; Scott, Barbara; Serrano, Beverly; Suchkov, Anatoly; Waczynski, Augustyn; Welty, Alan; Wheeler, Thomas; Wilson, Erin

    2011-07-01

    The ACS CCD Electronics Box Replacement (CEB-R) installed during SM4 features a Teledyne SIDECAR ASIC that permits optimization of the WFC via adjustment of CCD clock voltages, bias voltages, and pixel transmission timing. A built-in oscilloscope mode allows sensing of the analog signal from each output amplifier. An on-orbit campaign to optimize the performance of the WFC was undertaken at the start of the SMOV period. Initial tests with pre-SM4 default voltages and timing patterns showed that WFC's performance matches or exceeds its pre-failure levels, notwithstanding the expected increases in dark current and hot pixels and the decline in charge-transfer efficiency due to prolonged exposure to HST's radiation environment. The WFC2 CCD exhibited anomalous behavior when operated with nondefault settings of its amplifiers' reset-drain voltage (VOD). The CCD again displayed normal behavior when VOD was restored to its default setting. Consequently, the Optimization Campaign was truncated after two iterations, and ACS science operations commenced with the pre-SM4 default configuration.

  1. The Feasibility of Applying AC Driven Low-Temperature Plasma for Multi-Cycle Detonation Initiation

    NASA Astrophysics Data System (ADS)

    Zheng, Dianfeng

    2016-11-01

    Ignition is a key system in pulse detonation engines (PDE). As advanced ignition methods, nanosecond pulse discharge low-temperature plasma ignition is used in some combustion systems, and continuous alternating current (AC) driven low-temperature plasma using dielectric barrier discharge (DBD) is used for the combustion assistant. However, continuous AC driven plasmas cannot be used for ignition in pulse detonation engines. In this paper, experimental and numerical studies of pneumatic valve PDE using an AC driven low-temperature plasma igniter were described. The pneumatic valve was jointly designed with the low-temperature plasma igniter, and the numerical simulation of the cold-state flow field in the pneumatic valve showed that a complex flow in the discharge area, along with low speed, was beneficial for successful ignition. In the experiments ethylene was used as the fuel and air as oxidizing agent, ignition by an AC driven low-temperature plasma achieved multi-cycle intermittent detonation combustion on a PDE, the working frequency of the PDE reached 15 Hz and the peak pressure of the detonation wave was approximately 2.0 MPa. The experimental verifications of the feasibility in PDE ignition expanded the application field of AC driven low-temperature plasma. supported by National Natural Science Foundation of China (No. 51176001)

  2. Three phase AC motor controller

    DOEpatents

    Vuckovich, Michael; Wright, Maynard K.; Burkett, John P.

    1984-03-20

    A motor controller for a three phase AC motor (10) which is adapted to operate bidirectionally from signals received either from a computer (30) or a manual control (32). The controller is comprised of digital logic circuit means which implement a forward and reverse command signal channel (27, 29) for the application of power through the forward and reverse power switching relays (16, 18, 20, 22). The digital logic elements are cross coupled to prevent activation of both channels simultaneously and each includes a plugging circuit (65, 67) for stopping the motor upon the removal of control signal applied to one of the two channels (27, 29) for a direction of rotation desired. Each plugging circuit (65, 67) includes a one-shot pulse signal generator (88, 102) which outputs a single pulse signal of predetermined pulsewidth which is adapted to inhibit further operation of the application of power in the channel which is being activated and to apply a reversal command signal to the other channel which provides a reversed phase application of power to the motor for a period defined by the pulse-width output of the one-shot signal generator to plug the motor (10) which will then be inoperative until another rotational command signal is applied to either of the two channels.

  3. Reliable 100 kbps low-voltage ac powerline communications

    NASA Astrophysics Data System (ADS)

    Ladas, Chris; Propp, Michael

    1995-12-01

    Achieving reliable, 100 kbps powerline communications on the low voltage, AC powerlines has been realized by combining new techniques in spread spectrum technology with a robust, powerline specific protocol. This approach enables reliable, high speed data networking on the electrically hostile, low voltage powerline. Applications for the new technology include utility DA/DSM (distribution automation/demand side management), intraoffice LANs, powerline based telephony, and industrial data networking applications. This technological advancement was made possible through statistical modeling of the low voltage powerline, and developing unique spread spectrum and protocol techniques specific to the resulting powerline environment. The technology has been implemented as a highly integrated, CMOS chip set, allowing straightforward integration into OEM systems and products.

  4. Modeling AC ripple currents in HTS coated conductors by integral equations

    NASA Astrophysics Data System (ADS)

    Grilli, Francesco; Xu, Zhihan

    2016-12-01

    In several HTS applications, the superconducting tapes experience the simultaneous presence of DC and AC excitations. For example in high-current DC cables, where the transport current is not perfectly constant, but it exhibits some ripples at different frequencies introduced by the rectification process (AC-DC conversion). These ripples give rise to dissipation, whose magnitude and possible influence on the device's cooling requirements need to be evaluated. Here we report a study of the AC losses in a HTS coated conductor subjected to DC currents and AC ripples simultaneously. The modeling approach is based on an integral equation method for thin superconductors: the superconducting tape is modeled as a 1-D object with a non-linear resistivity, which includes the dependence of the critical current density Jc on the magnetic field. The model, implemented in a commercial finite-element program, runs very fast (the simulation of one AC cycle typically takes a few seconds on standard desktop workstation): this allows simulating a large number of cycles and estimating when the AC ripple losses stabilize to a constant value. The model is used to study the influence of the flux creep power index n on the stabilization speed and on the AC loss values, as well as the effect of using a field-dependent Jc instead of a constant one. The simulations confirm that the dissipation level should not be a practical concern in HTS DC cables. At the same time, however, they reveal a strong dependence of the results upon the power index n and the form of Jc , which spurs the question whether the power-law is the most suitable description of the superconductor's electrical behavior for this kind of analysis.

  5. Memory effect in ac plasma displays

    NASA Astrophysics Data System (ADS)

    Szlenk, K.; Obuchowicz, E.

    1993-10-01

    The bistable or `memory' mode of operation of an ac plasma display panel is presented. The difference between dc and ac plasma panel operation from the point of view of memory function is discussed. The graphic ac plasma display with thin film Cr-Cu-Cr electrodes was developed in OBREP and its basic parameters are described. It consists of 36 X 59 picture elements, its outer dimensions are: 76 X 52 mm2 and the screen size is: 49 X 30 mm2. The different dielectric glass materials were applied as dielectric layers and the influence of the properties of these materials on display parameters and memory function was investigated.

  6. Superconductor coil geometry and ac losses

    NASA Technical Reports Server (NTRS)

    Pierce, T. V., Jr.; Zapata, R. N.

    1976-01-01

    An empirical relation is presented which allows simple computation of volume-averaged winding fields from central fields for coils of small rectangular cross sections. This relation suggests that, in certain applications, ac-loss minimization can be accomplished by use of low winding densities, provided that hysteresis losses are independent of winding density. The ac-loss measurements on coils wound of twisted multifilamentary composite superconductors show no significant dependence on ac losses on winding density, thus permitting the use of winding density as an independent design parameter in loss minimization.

  7. Variable speed controller

    NASA Technical Reports Server (NTRS)

    Estes, Christa; Spiggle, Charles; Swift, Shannon; Vangeffen, Stephen; Younger, Frank

    1992-01-01

    This report details a new design for a variable speed controller which can be used to operate lunar machinery without the astronaut using his or her upper body. In order to demonstrate the design, a treadle for an industrial sewing machine was redesigned to be used by a standing operator. Since the invention of an electrically powered sewing machine, the operator has been seated. Today, companies are switching from sit down to stand up operation involving modular stations. The old treadle worked well with a sitting operator, but problems have been found when trying to use the same treadle with a standing operator. Emphasis is placed on the ease of use by the operator along with the ergonomics involved. Included with the design analysis are suggestions for possible uses for the speed controller in other applications.

  8. Forecasting Solar Wind Speeds

    NASA Astrophysics Data System (ADS)

    Suzuki, Takeru K.

    2006-03-01

    By explicitly taking into account the effects of Alfvén waves, I derive from a simple energetics argument a fundamental relation that predicts solar wind (SW) speeds in the vicinity of Earth from physical properties on the Sun. Kojima et al. recently found from observations that the ratio of surface magnetic field strength to the expansion factor of open magnetic flux tubes is a good indicator of the SW speed. I show by using the derived relation that this nice correlation is evidence of Alfvén wave acceleration of the SW in expanding flux tubes. The observations further require that the fluctuation amplitudes of magnetic field lines at the surface be almost universal in different coronal holes, which needs to be tested with future observations.

  9. High speed civil transport

    NASA Technical Reports Server (NTRS)

    Bogardus, Scott; Loper, Brent; Nauman, Chris; Page, Jeff; Parris, Rusty; Steinbach, Greg

    1990-01-01

    The design process of the High Speed Civil Transport (HSCT) combines existing technology with the expectation of future technology to create a Mach 3.0 transport. The HSCT was designed to have a range in excess of 6000 nautical miles and carry up to 300 passengers. This range will allow the HSCT to service the economically expanding Pacific Basin region. Effort was made in the design to enable the aircraft to use conventional airports with standard 12,000 foot runways. With a takeoff thrust of 250,000 pounds, the four supersonic through-flow engines will accelerate the HSCT to a cruise speed of Mach 3.0. The 679,000 pound (at takeoff) HSCT is designed to cruise at an altitude of 70,000 feet, flying above most atmospheric disturbances.

  10. Exenatide: AC 2993, AC002993, AC2993A, exendin 4, LY2148568.

    PubMed

    2004-01-01

    Exenatide [AC002993, AC2993A, AC 2993, LY2148568, exendin 4], a glucagon-like peptide-1 (GLP-1) agonist, is a synthetic exendin 4 compound under development with Amylin Pharmaceuticals for the treatment of type 2 diabetes. Both exendin 4 and its analogue, exendin 3, are 39-amino acid peptides isolated from Heloderma horridum lizard venom that have different amino acids at positions 2 and 3, respectively. Exendins are able to stimulate insulin secretion in response to rising blood glucose levels, and modulate gastric emptying to slow the entry of ingested sugars into the bloodstream. Amylin Pharmaceuticals acquired exclusive patent rights for the two exendin compounds (exendin 3 and exendin 4) from the originator, Dr John Eng (Bronx, NY, US). On 20 September 2002, Amylin and Eli Lilly signed a collaborative agreement for the development and commercialisation of exenatide for type 2 diabetes. Under the terms of the agreement, Eli Lilly has paid Amylin a licensing fee of 80 million US dollars and bought Amylin's stock worth 30 million US dollars at 18.69 US dollars a share. After the initial payment, Eli Lilly will pay Amylin up to 85 US dollars million upon reaching certain milestones and also make an additional payment of up to 130 million US dollars upon global commercialisation of exenatide. Both companies will share the US development and commercialisation costs, while Eli Lilly will pick up up to 80% of development costs and all commercialisation costs outside the US. Amylin and Eli Lilly will equally share profit from sales in the US, while Eli Lilly will get 80% of the profit outside the US and Amylin will get the rest. This agreement has also enabled Amylin to train its sales force to co-promote Lilly's human growth hormone Humatrope. Alkermes will receive research and development funding and milestone payments, and also a combination of royalty payments and manufacturing fees based on product sales. Alkermes undertakes the responsibility for the development

  11. MCCB warm adjustment testing concept

    NASA Astrophysics Data System (ADS)

    Erdei, Z.; Horgos, M.; Grib, A.; Preradović, D. M.; Rodic, V.

    2016-08-01

    This paper presents an experimental investigation in to operating of thermal protection device behavior from an MCCB (Molded Case Circuit Breaker). One of the main functions of the circuit breaker is to assure protection for the circuits where mounted in for possible overloads of the circuit. The tripping mechanism for the overload protection is based on a bimetal movement during a specific time frame. This movement needs to be controlled and as a solution to control this movement we choose the warm adjustment concept. This concept is meant to improve process capability control and final output. The warm adjustment device design will create a unique adjustment of the bimetal position for each individual breaker, determined when the testing current will flow thru a phase which needs to trip in a certain amount of time. This time is predetermined due to scientific calculation for all standard types of amperages and complies with the IEC 60497 standard requirements.

  12. Monitoring speed before and during a speed publicity campaign.

    PubMed

    van Schagen, Ingrid; Commandeur, Jacques J F; Goldenbeld, Charles; Stipdonk, Henk

    2016-12-01

    Driving speeds were monitored during a period of 16 weeks encompassing different stages of an anti-speeding campaign in the Netherlands. This campaign targeted speed limit violations in built-up areas. The observation periods differed in terms of intensity and media used for the campaign. Small road-side radars, mounted in light poles, were used and registered the speeds on 20 locations in built-up areas. Speeds of over 10 million vehicles were measured. Ten locations had a posted speed limit of 50km/h; the other ten had a posted speed limit of 30km/h. Posters were placed at half of each group of locations to remind drivers of the speed limit. The average speed on the 50km/h roads was 46.2km/h, and 36.1km/h on the 30km/h roads. The average proportions of vehicles exceeding the speed limit were 33.3% and 70.1% respectively. For the 30km/h roads, the data shows differences in speed and speeding behaviour between the six distinguished observation periods, but overall these differences cannot be logically linked to the contents of the phases and, hence, cannot be explained as an effect of the campaign. The only exception was an effect of local speed limit reminders on the 30km/h roads. This effect, however, was temporary and had disappeared within a week.

  13. Comparable-Worth Adjustments: Yes--Comparable-Worth Adjustments: No.

    ERIC Educational Resources Information Center

    Galloway, Sue; O'Neill, June

    1985-01-01

    Two essays address the issue of pay equity and present opinions favoring and opposing comparable-worth adjustments. Movement of women out of traditionally female jobs, the limits of "equal pay," fairness of comparable worth and market-based wages, implementation and efficiency of comparable worth system, and alternatives to comparable…

  14. Multi-speed transmission

    SciTech Connect

    Ashikawa, N.; Nakayama, H.; Sumi, M.

    1986-12-02

    This patent describes a multi-speed transmission having forward speed gear trains and at least one reverse speed gear train, comprising, a pair of parallel fork shafts, one the shaft being fixed, the other the shaft being slidable along its axial direction, means to selectively engage the gear trains and means to retain the selective engagement means in the selected position. The means selectively engages the gear trains including a first shift fork connected to the fixed fork shaft so as to slide to either side of its disengaged neutral position, a second shift fork connected to the slideable fork shaft so as to slide to either side of its disengaged neutral position, and a third shift fork connected to the slidable fork shaft so as to slide in one direction by motion of the slideable fork shaft to only one side of its disengaged neutral position. Also included is a reverse shift fork connected to the slideable fork shaft and adapted to be actuated by motion of the slideable fork shaft in a direction opposite to the direction of the motion which engages the third shift fork.

  15. Two-speed transaxle

    DOEpatents

    Kalns, Ilmars

    1981-01-01

    Disclosed is a drive assembly (10) for an electrically powered vehicle (12). The assembly includes a transaxle (16) having a two-speed transmission (40) and a drive axle differential (46) disposed in a unitary housing assembly (38), an oil-cooled prime mover or electric motor (14) for driving the transmission input shaft (42), an adapter assembly (24) for supporting the prime mover on the transaxle housing assembly, and a hydraulic system (172) providing pressurized oil flow for cooling and lubricating the electric motor and transaxle and for operating a clutch (84) and a brake (86) in the transmission to shift between the two-speed ratios of the transmission. The adapter assembly allows the prime mover to be supported in several positions on the transaxle housing. The brake is spring-applied and locks the transmission in its low-speed ratio should the hydraulic system fail. The hydraulic system pump is driven by an electric motor (212) independent of the prime mover and transaxle.

  16. Do speed cameras reduce speeding in urban areas?

    PubMed

    Oliveira, Daniele Falci de; Friche, Amélia Augusta de Lima; Costa, Dário Alves da Silva; Mingoti, Sueli Aparecida; Caiaffa, Waleska Teixeira

    2015-11-01

    This observational study aimed to estimate the prevalence of speeding on urban roadways and to analyze associated factors. The sample consisted of 8,565 vehicles circulating in areas with and without fixed speed cameras in operation. We found that 40% of vehicles 200 meters after the fixed cameras and 33.6% of vehicles observed on roadways without speed cameras were moving over the speed limit (p < 0.001). Motorcycles showed the highest recorded speed (126km/h). Most drivers were men (87.6%), 3.3% of all drivers were using their cell phones, and 74.6% of drivers (not counting motorcyclists) were wearing their seatbelts. On roadway stretches without fixed speed cameras, more women drivers were talking on their cell phones and wearing seatbelts when compared to men (p < 0.05 for both comparisons), independently of speed limits. The results suggest that compliance with speed limits requires more than structural interventions.

  17. 75 FR 33379 - Railroad Cost Recovery Procedures-Productivity Adjustment; Quarterly Rail Cost Adjustment Factor

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-11

    ... Surface Transportation Board Railroad Cost Recovery Procedures--Productivity Adjustment; Quarterly Rail... Railroads that the Board restate the previously published productivity adjustment for the 2003-2007 averaging period (2007 productivity adjustment) so that it tracks the 2007 productivity adjustment...

  18. High School Teachers Win ACS Prizes

    NASA Astrophysics Data System (ADS)

    Editorial Staff, Jce

    2009-07-01

    William E. Snyder is the 2009 winner of the ACS Division of Chemical Education Central Region Award for Excellence in High School Teaching; Sally Mitchell is the winner of the 2009 James Bryant Conant Award in High School Chemistry Teaching.

  19. The AC-120: The advanced commercial transport

    NASA Technical Reports Server (NTRS)

    Duran, David; Griffin, Ernest; Mendoza, Saul; Nguyen, Son; Pickett, Tim; Noernberg, Clemm

    1993-01-01

    The main objective of this design was to fulfill a need for a new airplane to replace the aging 100 to 150 passenger, 1500 nautical mile range aircraft such as the Douglas DC9 and Boeing 737-100 airplanes. After researching the future aircraft market, conducting extensive trade studies, and analysis on different configurations, the AC-120 Advanced Commercial Transport final design was achieved. The AC-120's main design features include the incorporation of a three lifting surface configuration which is powered by two turboprop engines. The AC-120 is an economically sensitive aircraft which meets the new FM Stage Three noise requirements, and has lower NO(x) emissions than current turbofan powered airplanes. The AC-120 also improves on its contemporaries in passenger comfort, manufacturing, and operating cost.

  20. The role of visual processing speed in reading speed development.

    PubMed

    Lobier, Muriel; Dubois, Matthieu; Valdois, Sylviane

    2013-01-01

    A steady increase in reading speed is the hallmark of normal reading acquisition. However, little is known of the influence of visual attention capacity on children's reading speed. The number of distinct visual elements that can be simultaneously processed at a glance (dubbed the visual attention span), predicts single-word reading speed in both normal reading and dyslexic children. However, the exact processes that account for the relationship between the visual attention span and reading speed remain to be specified. We used the Theory of Visual Attention to estimate visual processing speed and visual short-term memory capacity from a multiple letter report task in eight and nine year old children. The visual attention span and text reading speed were also assessed. Results showed that visual processing speed and visual short term memory capacity predicted the visual attention span. Furthermore, visual processing speed predicted reading speed, but visual short term memory capacity did not. Finally, the visual attention span mediated the effect of visual processing speed on reading speed. These results suggest that visual attention capacity could constrain reading speed in elementary school children.

  1. Three-phase-to-two-phase direct AC-AC converter with three leg structure

    NASA Astrophysics Data System (ADS)

    Kwak, S.-S.

    2014-05-01

    A three-phase-to-two-phase ac-ac converter is, along with a modulation strategy based on the space vector scheme, introduced to directly drive two-phase output ac systems with high input power quality. The converter is capable of synthesising two sinusoidal output voltages with variable output frequency and arbitrary magnitude in quadrature phase-shift as well as sinusoidal input currents.

  2. Phase protection system for ac power lines

    NASA Technical Reports Server (NTRS)

    Wong, W. J. (Inventor)

    1974-01-01

    The system described provides protection for phase sensitive loads from being or remaining connected to ac power lines whenever a phase reversal occurs. It comprises a solid state phase detection circuit, a dc power relay circuit, an ac-to-dc converter for energizing the relay circuit, and a bistable four terminal transducer coupled between the phase detection circuit and the power relay circuit, for controlling both circuits.

  3. Adjustable Optical-Fiber Attenuator

    NASA Technical Reports Server (NTRS)

    Buzzetti, Mike F.

    1994-01-01

    Adjustable fiber-optic attenuator utilizes bending loss to reduce strength of light transmitted along it. Attenuator functions without introducing measurable back-reflection or insertion loss. Relatively insensitive to vibration and changes in temperature. Potential applications include cable television, telephone networks, other signal-distribution networks, and laboratory instrumentation.

  4. Dyadic Adjustment: An Ecosystemic Examination.

    ERIC Educational Resources Information Center

    Wilson, Stephan M.; Larson, Jeffry H.; McCulloch, B. Jan; Stone, Katherine L.

    1997-01-01

    Examines the relationship of background, individual, and family influences on dyadic adjustment, using an ecological perspective. Data from 102 married couples were used. Age at marriage for husbands, emotional health for wives, and number of marriage and family problems as well as family life satisfaction for both were related to dyadic…

  5. Problems of Adjustment to School.

    ERIC Educational Resources Information Center

    Bartolini, Leandro A.

    This paper, one of several written for a comprehensive policy study of early childhood education in Illinois, examines and summarizes the literature on the problems of young children in adjusting to starting school full-time and describes the nature and extent of their difficulties in relation to statewide educational policy. The review of studies…

  6. Economic Pressures and Family Adjustment.

    ERIC Educational Resources Information Center

    Haccoun, Dorothy Markiewicz; Ledingham, Jane E.

    The relationships between economic stress on the family and child and parental adjustment were examined for a sample of 199 girls and boys in grades one, four, and seven. These associations were examined separately for families in which both parents were present and in which mothers only were at home. Economic stress was associated with boys'…

  7. Microtubule alignment and manipulation using AC electrokinetics.

    PubMed

    Uppalapati, Maruti; Huang, Ying-Ming; Jackson, Thomas N; Hancock, William O

    2008-09-01

    The kinesin-microtubule system plays an important role in intracellular transport and is a model system for integrating biomotor-driven transport into microengineered devices. AC electrokinetics provides a novel tool for manipulating and organizing microtubules in solution, enabling new experimental geometries for investigating and controlling the interactions of microtubules and microtubule motors in vitro. By fabricating microelectrodes on glass substrates and generating AC electric fields across solutions of microtubules in low-ionic-strength buffers, bundles of microtubules are collected and aligned and the electrical properties of microtubules in solution are measured. The AC electric fields result in electro-osmotic flow, electrothermal flow, and dielectrophoresis of microtubules, which can be controlled by varying the solution conductivity, AC frequency, and electrode geometry. By mapping the solution conductivity and AC frequency over which positive dielectrophoresis occurs, the apparent conductivity of taxol-stabilized bovine-brain microtubules in PIPES buffer is measured to be 250 mS m(-1). By maximizing dielectrophoretic forces and minimizing electro-osmotic and electrothermal flow, microtubules are assembled into opposed asters. These experiments demonstrate that AC electrokinetics provides a powerful new tool for kinesin-driven transport applications and for investigating the role of microtubule motors in development and maintenance of the mitotic spindle.

  8. Posterror speeding after threat-detection failure.

    PubMed

    Caudek, Corrado; Ceccarini, Francesco; Sica, Claudio

    2015-04-01

    Cognitive control enables individuals to rapidly adapt to changing task demands. To investigate error-driven adjustments in cognitive control, we considered performance changes in posterror trials, when participants performed a visual search task requiring detection of angry, happy, or neutral facial expressions in crowds of faces. We hypothesized that the failure to detect a potential threat (angry face) would prompt a different posterror adjustment than the failure to detect a nonthreatening target (happy or neutral face). Indeed, in 3 sets of experiments, we found evidence of posterror speeding, in the first case, and of posterror slowing, in the second case. Previous results indicate that a threatening stimulus can improve the efficiency of visual search. The results of the present study show that a similar effect can also be observed when participants fail to detect a threat. The impact of threat-detection failure on cognitive control, as revealed by the present study, suggests that posterror adjustments should be understood as the product of domain-specific mechanisms that are strongly influenced by affective information, rather than as the effect of a general-purpose error-monitoring system.

  9. High speed flywheel

    DOEpatents

    McGrath, Stephen V.

    1991-01-01

    A flywheel for operation at high speeds utilizes two or more ringlike coments arranged in a spaced concentric relationship for rotation about an axis and an expansion device interposed between the components for accommodating radial growth of the components resulting from flywheel operation. The expansion device engages both of the ringlike components, and the structure of the expansion device ensures that it maintains its engagement with the components. In addition to its expansion-accommodating capacity, the expansion device also maintains flywheel stiffness during flywheel operation.

  10. Low speed airfoil study

    NASA Technical Reports Server (NTRS)

    Ormsbee, A. I.

    1977-01-01

    Airfoil geometries were developed for low speed high lift applications, such as general aviation aircraft, propellers and helicopter rotors. The primary effort was to determine the extent to which the application of turbulent boundary layer separation criteria, plus manipulation of other input parameters, specifically trailing edging velocity ratio, could be utilized to achieve high C sub Lmax airfoils with relatively low drag at C sub Lmax. Both single-element and double-element airfoils were considered. Wind tunnel testing of some airfoils was included.

  11. Controlling speed and direction during interception: an affordance-based approach.

    PubMed

    Bastin, Julien; Fajen, Brett R; Montagne, Gilles

    2010-04-01

    The coordination of direction and speed of self-motion when intercepting a target moving parallel to the ground plane was examined. Subjects viewed a computer-generated environment comprised of a textured ground plane and a moving target. Turning rate was controlled using a steering wheel and speed was controlled using a foot pedal. It was hypothesized that these two degrees of freedom would be coordinated such that the speed required to intercept the target (i.e., the ideal speed) would be maintained below the subject's maximum possible speed. As predicted, subjects turned toward the target when ideal speed was less than maximum speed and ahead of the target when ideal speed was greater than maximum speed. When behavior was compared across groups with different maximum speed capabilities, it was found that the ratio of ideal to maximum speed was invariant across groups at critical points of both steering and speed adjustments. Finally, subjects rapidly recalibrated to a sudden increase or decrease in maximum speed. The results suggest that actors coordinate steering and speed during interception in a way that takes into account the limits on their action capabilities. Discussion focuses on the role of calibration and the implications of the present findings for existing models of visually guided interception.

  12. Discrepancy between actual and estimated speeds of drivers in the presence of child pedestrians

    PubMed Central

    Harre, N

    2003-01-01

    Objectives: First, to measure the speeds of vehicles with and without children on the footpath, and second to compare these with drivers' estimates of how fast they would go in these conditions. Design: The speeds of vehicles in three conditions: control (no children present), children playing with a ball on the footpath, and children waiting to cross the road, were measured using speed tubes during two 55 minute sessions. Drivers' estimates of their speeds were measured with a questionnaire. Setting: Speeds were measured on a main road in Auckland, New Zealand. The questionnaire was conducted at another time with drivers stopping for petrol approximately 500 metres from the measurement site. Subjects: A total of 1446 speed measurements were taken and 93 drivers‘ questionnaire responses were analysed. Results: The mean free speed of vehicles in the control condition was 55.60 kph, with drivers‘ estimates being 56.37 kph. When children were playing with a ball the measured speed was 54.29 kph and the estimated speed 39.27 kph. When children were waiting to cross the measured speed was 52.78 kph, estimated speed 34.02 kph. Analyses indicated that there were significant differences between measured and estimated speeds. Conclusions: New Zealand drivers make inadequate speed adjustments in the presence of children, despite probably believing they do so. Establishing specific rules about appropriate speeds around children and highlighting to drivers the discrepancy between their attitudes and behaviour are two intervention strategies suggested. PMID:12642557

  13. Speed versus accuracy in collective decision making.

    PubMed Central

    Franks, Nigel R; Dornhaus, Anna; Fitzsimmons, Jon P; Stevens, Martin

    2003-01-01

    We demonstrate a speed versus accuracy trade-off in collective decision making. House-hunting ant colonies choose a new nest more quickly in harsh conditions than in benign ones and are less discriminating. The errors that occur in a harsh environment are errors of judgement not errors of omission because the colonies have discovered all of the alternative nests before they initiate an emigration. Leptothorax albipennis ants use quorum sensing in their house hunting. They only accept a nest, and begin rapidly recruiting members of their colony, when they find within it a sufficient number of their nest-mates. Here we show that these ants can lower their quorum thresholds between benign and harsh conditions to adjust their speed-accuracy trade-off. Indeed, in harsh conditions these ants rely much more on individual decision making than collective decision making. Our findings show that these ants actively choose to take their time over judgements and employ collective decision making in benign conditions when accuracy is more important than speed. PMID:14667335

  14. Keratinocyte galvanotaxis in combined DC and AC electric fields supports an electromechanical transduction sensing mechanism.

    PubMed

    Hart, Francis X; Laird, Mhairi; Riding, Aimie; Pullar, Christine E

    2013-02-01

    Sedentary keratinocytes at the edge of a skin wound migrate into the wound, guided by the generation of an endogenous electric field (EF) generated by the collapse of the transepithelial potential. The center of the wound quickly becomes more negative than the surrounding tissue and remains the cathode of the endogenous EF until the wound is completely re-epithelialized. This endogenous guidance cue can be studied in vitro. When placed in a direct current (DC) EF of physiological strength, 100 V/m, keratinocytes migrate directionally toward the cathode in a process known as galvanotaxis. Although a number of membrane-bound (e.g., epidermal growth factor receptor (EGFR), integrins) and cytosolic proteins (cAMP, ERK, PI3K) are known to play a role in the downstream signaling mechanisms underpinning galvanotaxis, the initial sensing mechanism for this response is not understood. To investigate the EF sensor, we studied the migration of keratinocytes in a DC EF of 100 V/m, alternating current (AC) EFs of 40 V/m at either 1.6 or 160 Hz, and combinations of DC and AC EFs. In the AC EFs alone, keratinocytes migrated randomly. The 1.6 Hz AC EF combined with the DC EF suppressed the direction of migration but had no effect on speed. In contrast, the 160 Hz AC EF combined with the DC EF did not affect the direction of migration but increased the migration speed compared to the DC EF alone. These results can be understood in terms of an electromechanical transduction model, but not an electrodiffusion/osmosis or a voltage-gated channel model.

  15. 21 CFR 886.1630 - AC-powered photostimulator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered photostimulator. 886.1630 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1630 AC-powered photostimulator. (a) Identification. An AC-powered photostimulator is an AC-powered device intended to provide light stimulus...

  16. 21 CFR 886.1630 - AC-powered photostimulator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered photostimulator. 886.1630 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1630 AC-powered photostimulator. (a) Identification. An AC-powered photostimulator is an AC-powered device intended to provide light stimulus...

  17. 21 CFR 886.1850 - AC-powered slitlamp biomicroscope.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered slitlamp biomicroscope. 886.1850... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1850 AC-powered slitlamp biomicroscope. (a) Identification. An AC-powered slitlamp biomicroscope is an AC-powered device that is...

  18. 21 CFR 886.1850 - AC-powered slitlamp biomicroscope.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered slitlamp biomicroscope. 886.1850... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1850 AC-powered slitlamp biomicroscope. (a) Identification. An AC-powered slitlamp biomicroscope is an AC-powered device that is...

  19. 21 CFR 888.1240 - AC-powered dynamometer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered dynamometer. 888.1240 Section 888.1240...) MEDICAL DEVICES ORTHOPEDIC DEVICES Diagnostic Devices § 888.1240 AC-powered dynamometer. (a) Identification. An AC-powered dynamometer is an AC-powered device intended for medical purposes to...

  20. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and...

  1. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and...

  2. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and...

  3. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and...

  4. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and...

  5. 21 CFR 888.1240 - AC-powered dynamometer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered dynamometer. 888.1240 Section 888.1240...) MEDICAL DEVICES ORTHOPEDIC DEVICES Diagnostic Devices § 888.1240 AC-powered dynamometer. (a) Identification. An AC-powered dynamometer is an AC-powered device intended for medical purposes to...

  6. AC Electrokinetics of Physiological Fluids for Biomedical Applications.

    PubMed

    Lu, Yi; Liu, Tingting; Lamanda, Ariana C; Sin, Mandy L Y; Gau, Vincent; Liao, Joseph C; Wong, Pak Kin

    2015-12-01

    Alternating current (AC) electrokinetics is a collection of processes for manipulating bulk fluid mass and embedded objects with AC electric fields. The ability of AC electrokinetics to implement the major microfluidic operations, such as pumping, mixing, concentration, and separation, makes it possible to develop integrated systems for clinical diagnostics in nontraditional health care settings. The high conductivity of physiological fluids presents new challenges and opportunities for AC electrokinetics-based diagnostic systems. In this review, AC electrokinetic phenomena in conductive physiological fluids are described followed by a review of the basic microfluidic operations and the recent biomedical applications of AC electrokinetics. The future prospects of AC electrokinetics for clinical diagnostics are presented.

  7. AC Electrokinetics of Physiological Fluids for Biomedical Applications

    PubMed Central

    Lu, Yi; Liu, Tingting; Lamanda, Ariana C.; Sin, Mandy L Y; Gau, Vincent; Liao, Joseph C.; Wong, Pak Kin

    2016-01-01

    AC electrokinetics is a collection of processes for manipulating bulk fluid mass and embedded objects with AC electric fields. The ability of AC electrokinetics to implement the major microfluidic operations, such as pumping, mixing, concentration and separation, makes it possible to develop integrated systems for clinical diagnostics in non-traditional healthcare settings. The high conductivity of physiological fluids presents new challenges and opportunities for AC electrokinetics based diagnostic systems. In this review, AC electrokinetic phenomena in conductive physiological fluids are described followed by a review of the basic microfluidic operations and the recent biomedical applications of AC electrokinetics. The future prospects of AC electrokinetics for clinical diagnostics are presented. PMID:25487557

  8. High speed transient sampler

    DOEpatents

    McEwan, T.E.

    1995-11-28

    A high speed sampler comprises a meandered sample transmission line for transmitting an input signal, a straight strobe transmission line for transmitting a strobe signal, and a plurality of sampling gates along the transmission lines. The sampling gates comprise a four terminal diode bridge having a first strobe resistor connected from a first terminal of the bridge to the positive strobe line, a second strobe resistor coupled from the third terminal of the bridge to the negative strobe line, a tap connected to the second terminal of the bridge and to the sample transmission line, and a sample holding capacitor connected to the fourth terminal of the bridge. The resistance of the first and second strobe resistors is much higher than the signal transmission line impedance in the preferred system. This results in a sampling gate which applies a very small load on the sample transmission line and on the strobe generator. The sample holding capacitor is implemented using a smaller capacitor and a larger capacitor isolated from the smaller capacitor by resistance. The high speed sampler of the present invention is also characterized by other optimizations, including transmission line tap compensation, stepped impedance strobe line, a multi-layer physical layout, and unique strobe generator design. A plurality of banks of such samplers are controlled for concatenated or interleaved sample intervals to achieve long sample lengths or short sample spacing. 17 figs.

  9. High speed transient sampler

    DOEpatents

    McEwan, Thomas E.

    1995-01-01

    A high speed sampler comprises a meandered sample transmission line for transmitting an input signal, a straight strobe transmission line for transmitting a strobe signal, and a plurality of sampling gates along the transmission lines. The sampling gates comprise a four terminal diode bridge having a first strobe resistor connected from a first terminal of the bridge to the positive strobe line, a second strobe resistor coupled from the third terminal of the bridge to the negative strobe line, a tap connected to the second terminal of the bridge and to the sample transmission line, and a sample holding capacitor connected to the fourth terminal of the bridge. The resistance of the first and second strobe resistors is much higher than the signal transmission line impedance in the preferred system. This results in a sampling gate which applies a very small load on the sample transmission line and on the strobe generator. The sample holding capacitor is implemented using a smaller capacitor and a larger capacitor isolated from the smaller capacitor by resistance. The high speed sampler of the present invention is also characterized by other optimizations, including transmission line tap compensation, stepped impedance strobe line, a multi-layer physical layout, and unique strobe generator design. A plurality of banks of such samplers are controlled for concatenated or interleaved sample intervals to achieve long sample lengths or short sample spacing.

  10. Ultrasound speed and attenuation in progressive trypsin digested articular cartilage.

    PubMed

    Niu, HaiJun; Li, LiFeng; Sun, Feng; Yan, Yan; Wang, YueXiang; Li, DeYu; Fan, YuBo

    2011-11-01

    Subtle changes of articular cartilage (AC) can lead to tissue degeneration and even osteoarthritis (OA). The early degeneration of AC is closely related to a change in proteoglycans (PG) content. The observation of PG is therefore an appropriate way of studying OA and evaluating the degree of AC degeneration. In this study, 20 cartilage-bone samples were prepared from normal porcine femoral condyle cartilage and 10 samples were digested over 2 h using 0.25% trypsin solution. The dynamic process of PG-digestion was explored using a conventional A-mode ultrasound (US) experimental system with a 10 MHz center frequency. Quantitative acoustic parameters were calculated from ultrasonic radio-frequency echo signals and included US speed (USS), US amplitude attenuation coefficient (UAA) and broadband US attenuation coefficient (BUA). The experimental results showed that the conventional A-mode ultrasound is valuable for tracking the degree of PG-digestion. Histology also confirmed the validity of the ultrasound observations. For every AC sample, the degree of PG-digestion within a given time was different and was affected by individual differences. After two hours of degeneration, USS showed a mean decrease of 0.4% (P<0.05). UAA was significantly lower after a two-hour PG depletion period (from (2.45±0.23) to (2.28±0.41) dB mm⁻¹). BUA showed no significant differences during this process. In conclusion, conventional ultrasound can provide useful information about trypsin-induced progressive PG depletion in AC and can reflect variations of PG content via the quantitative acoustic parameters USS and UAA. The results of this study may be used to identify an indirect indicator of cartilage matrix integrity and OA disease progression.

  11. Prospects for Brushless ac Motors with HTS Rotors

    NASA Astrophysics Data System (ADS)

    McCulloch, M. D.; Jim, K.; Kawai, Y.; Dew-Hughes, D.; Morgan, C.; Goringe, M. J.; Grovenor, C. R. M.

    1997-03-01

    There is a superconducting equivalent for every type of brushless ac motor; permanent magnet, reluctance, hysteresis and induction (squirrel cage) motor. The particular advantage of superconducting versions of these machines is that they are expected to provide much higher power densities than their conventional equivalents. The behaviour of superconducting rotors fabricated in the form of (a) squirrell cages from silver coated with melt-processed Bi-2212, (b) tubes cast centifugally from Bi-2212, and (c) small cylinders of melt-processed and seeded YBCO has been studied in rotating magnetic fields provided by conventional motor coils. Measurements of static torque, and values of dynamic torque deduced from angular velocity and acceleration have been used to characterise the potential performance of these embryonic machines. Two broad types of behaviour have been observed. In the Bi-2212 rotors the torque decreases with increasing rotor speed; this behaviour is believed due to flux creep. By contrast the strong-pinning YBCO rotors maintain a constant torque up to synchronous speed. Mathematical modelling of flux penetration and distribution within the rotors is able to reproduce both types of the observed behaviour. Power densities some 5 to 10 times that of conventional machines are predicted to be achievable in optimised prototype machines.

  12. 12 CFR 19.240 - Inflation adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Inflation adjustments. 19.240 Section 19.240... PROCEDURE Civil Money Penalty Inflation Adjustments § 19.240 Inflation adjustments. (a) The maximum amount of each civil money penalty within the OCC's jurisdiction is adjusted in accordance with the...

  13. 12 CFR 19.240 - Inflation adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Inflation adjustments. 19.240 Section 19.240... PROCEDURE Civil Money Penalty Inflation Adjustments § 19.240 Inflation adjustments. (a) The maximum amount... Civil Penalties Inflation Adjustment Act of 1990 (28 U.S.C. 2461 note) as follows: ER10NO08.001 (b)...

  14. 12 CFR 19.240 - Inflation adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Inflation adjustments. 19.240 Section 19.240... PROCEDURE Civil Money Penalty Inflation Adjustments § 19.240 Inflation adjustments. (a) The maximum amount... Civil Penalties Inflation Adjustment Act of 1990 (28 U.S.C. 2461 note) as follows: ER10NO08.001 (b)...

  15. Adjusting to University: The Hong Kong Experience

    ERIC Educational Resources Information Center

    Yau, Hon Keung; Sun, Hongyi; Cheng, Alison Lai Fong

    2012-01-01

    Students' adjustment to the university environment is an important factor in predicting university outcomes and is crucial to their future achievements. University support to students' transition to university life can be divided into three dimensions: academic adjustment, social adjustment and psychological adjustment. However, these…

  16. The History and State of the Art of Variable-Speed Wind Turbine Technology

    NASA Astrophysics Data System (ADS)

    Carlin, P. W.; Laxson, A. S.; Muljadi, E. B.

    2003-04-01

    Early wind turbines used for performing mechanical work (pumping, grinding and cutting) optimized aerodynamics by being allowed to run at variable speed. Some of the earliest DC electric wind turbines were allowed to run at variable speed. With the advent of grid-connected AC turbines, rotational speeds were limited in order to control the wind turbine AC frequency output to equal the grid frequency. With the advent of semiconductor devices, attempts began as early as the 1970s to allow variable-speed operation of large-scale turbines. The introduction of a new generation of high-voltage, high-speed power electronic components allows a wide range of variable-speed operation for very-large-scale machines. Over the past 30 years a number of designs have been tested, a few of which have entered commercial operation. A number of these designs and their histories are described. A detailed description of a wide range of electrical methods for allowing variable-speed operation is provided.

  17. 78 FR 49318 - Availability of Draft Advisory Circular (AC) 90-106A and AC 20-167A

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-13

    ... Federal Aviation Administration Availability of Draft Advisory Circular (AC) 90-106A and AC 20- 167A...: This notice announces the availability of draft Advisory Circular (AC) 90-106A, Enhanced Flight Vision Systems and draft AC 20- 167A, Airworthiness Approval of Enhanced Vision System, Synthetic Vision...

  18. Coverage-adjusted entropy estimation.

    PubMed

    Vu, Vincent Q; Yu, Bin; Kass, Robert E

    2007-09-20

    Data on 'neural coding' have frequently been analyzed using information-theoretic measures. These formulations involve the fundamental and generally difficult statistical problem of estimating entropy. We review briefly several methods that have been advanced to estimate entropy and highlight a method, the coverage-adjusted entropy estimator (CAE), due to Chao and Shen that appeared recently in the environmental statistics literature. This method begins with the elementary Horvitz-Thompson estimator, developed for sampling from a finite population, and adjusts for the potential new species that have not yet been observed in the sample-these become the new patterns or 'words' in a spike train that have not yet been observed. The adjustment is due to I. J. Good, and is called the Good-Turing coverage estimate. We provide a new empirical regularization derivation of the coverage-adjusted probability estimator, which shrinks the maximum likelihood estimate. We prove that the CAE is consistent and first-order optimal, with rate O(P)(1/log n), in the class of distributions with finite entropy variance and that, within the class of distributions with finite qth moment of the log-likelihood, the Good-Turing coverage estimate and the total probability of unobserved words converge at rate O(P)(1/(log n)(q)). We then provide a simulation study of the estimator with standard distributions and examples from neuronal data, where observations are dependent. The results show that, with a minor modification, the CAE performs much better than the MLE and is better than the best upper bound estimator, due to Paninski, when the number of possible words m is unknown or infinite.

  19. Pitch-controlled variable-speed wind turbine generation

    SciTech Connect

    Muljadi, E.; Butterfield, C.P.

    2000-03-01

    Wind energy is a viable option to complement other types of pollution-free generation. In the early development of wind energy, the majority of wind turbines were operated at constant speed. Recently, the number of variable-speed wind turbines installed in wind farms has increased and more wind turbine manufacturers are making variable-speed wind turbines. This paper covers the operation of variable-speed wind turbines with pitch control. The system the authors considered is controlled to generate maximum energy while minimizing loads. The maximization of energy was only carried out on a static basis and only drive train loads were considered as a constraint. In medium wind speeds, the generator and power converter control the wind turbine to capture maximum energy from the wind. In the high wind speed region, the wind turbine is controlled to maintain the aerodynamic power produced by the wind turbine. Two methods to adjust the aerodynamic power were investigated: pitch control and generator load control, both of which are employed to control the operation of the wind turbine. The analysis and simulation shows that the wind turbine can be operated at its optimum energy capture while minimizing the load on the wind turbine for a wide range of wind speeds.

  20. High speed packet switching

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This document constitutes the final report prepared by Proteon, Inc. of Westborough, Massachusetts under contract NAS 5-30629 entitled High-Speed Packet Switching (SBIR 87-1, Phase 2) prepared for NASA-Greenbelt, Maryland. The primary goal of this research project is to use the results of the SBIR Phase 1 effort to develop a sound, expandable hardware and software router architecture capable of forwarding 25,000 packets per second through the router and passing 300 megabits per second on the router's internal busses. The work being delivered under this contract received its funding from three different sources: the SNIPE/RIG contract (Contract Number F30602-89-C-0014, CDRL Sequence Number A002), the SBIR contract, and Proteon. The SNIPE/RIG and SBIR contracts had many overlapping requirements, which allowed the research done under SNIPE/RIG to be applied to SBIR. Proteon funded all of the work to develop new router interfaces other than FDDI, in addition to funding the productization of the router itself. The router being delivered under SBIR will be a fully product-quality machine. The work done during this contract produced many significant findings and results, summarized here and explained in detail in later sections of this report. The SNIPE/RIG contract was completed. That contract had many overlapping requirements with the SBIR contract, and resulted in the successful demonstration and delivery of a high speed router. The development that took place during the SNIPE/RIG contract produced findings that included the choice of processor and an understanding of the issues surrounding inter processor communications in a multiprocessor environment. Many significant speed enhancements to the router software were made during that time. Under the SBIR contract (and with help from Proteon-funded work), it was found that a single processor router achieved a throughput significantly higher than originally anticipated. For this reason, a single processor router was

  1. Atypical anticipatory postural adjustments during gait initiation among individuals with sub-acute stroke.

    PubMed

    Rajachandrakumar, Roshanth; Fraser, Julia E; Schinkel-Ivy, Alison; Inness, Elizabeth L; Biasin, Lou; Brunton, Karen; McIlroy, William E; Mansfield, Avril

    2017-02-01

    Anticipatory postural adjustments, executed prior to gait initiation, help preserve lateral stability when stepping. Atypical patterns of anticipatory activity prior to gait initiation may occur in individuals with unilateral impairment (e.g., stroke). This study aimed to determine the prevalence, correlates, and consequences of atypical anticipatory postural adjustment patterns prior to gait initiation in a sub-acute stroke population. Forty independently-ambulatory individuals with sub-acute stroke stood on two force plates and initiated gait at a self-selected speed. Medio-lateral centre of pressure displacement was calculated and used to define anticipatory postural adjustments (shift in medio-lateral centre of pressure >10mm from baseline). Stroke severity, motor recovery, and functional balance and mobility status were also obtained. Three patterns were identified: single (typical), absent (atypical), and multiple (atypical) anticipatory postural adjustments. Thirty-five percent of trials had atypical anticipatory postural adjustments (absent and multiple). Frequency of absent anticipatory postural adjustments was negatively correlated with walking speed. Multiple anticipatory postural adjustments were more prevalent when leading with the non-paretic than the paretic limb. Trials with multiple anticipatory postural adjustments had longer duration of anticipatory postural adjustment and time to foot-off, and shorter unloading time than trials with single anticipatory postural adjustments. A high prevalence of atypical anticipatory control prior to gait initiation was found in individuals with stroke. Temporal differences were identified with multiple anticipatory postural adjustments, indicating altered gait initiation. These findings provide insight into postural control during gait initiation in individuals with sub-acute stroke, and may inform interventions to improve ambulation in this population.

  2. Design and synthesis of 225Ac radioimmunopharmaceuticals.

    PubMed

    McDevitt, Michael R; Ma, Dangshe; Simon, Jim; Frank, R Keith; Scheinberg, David A

    2002-12-01

    The alpha-particle-emitting radionuclides 213Bi, 211At, 224Ra are under investigation for the treatment of leukemias, gliomas, and ankylosing spondylitis, respectively. 213Bi and 211At were attached to monoclonal antibodies and used as targeted immunotherapeutic agents while unconjugated 224Ra chloride selectively seeks bone. 225Ac possesses favorable physical properties for radioimmunotherapy (10d half-life and 4 net alpha particles), but has a history of unfavorable radiolabeling chemistry and poor metal-chelate stability. We selected functionalized derivatives of DOTA as the most promising to pursue from out of a group of potential 225Ac chelate compounds. A two-step synthetic process employing either MeO-DOTA-NCS or 2B-DOTA-NCS as the chelating moiety was developed to attach 225Ac to monoclonal antibodies. This method was tested using several different IgG systems. The chelation reaction yield in the first step was 93+/-8% radiochemically pure (n=26). The second step yielded 225Ac-DOTA-IgG constructs that were 95+/-5% radiochemically pure (n=27) and the mean percent immunoreactivity ranged from 25% to 81%, depending on the antibody used. This process has yielded several potential novel targeted 225Ac-labeled immunotherapeutic agents that may now be evaluated in appropriate model systems and ultimately in humans.

  3. From Beamline to Scanner with 225Ac

    NASA Astrophysics Data System (ADS)

    Robertson, Andrew K. H.; Ramogida, Caterina F.; Kunz, Peter; Rodriguez-Rodriguez, Cristina; Schaffer, Paul; Sossi, Vesna

    2016-09-01

    Due to the high linear energy transfer and short range of alpha-radiation, targeted radiation therapy using alpha-emitting pharmaceuticals that successfully target small disease clusters will kill target cells with limited harm to healthy tissue, potentially treating the most aggressive forms of cancer. As the parent of a decay chain with four alpha- and two beta-decays, 225Ac is a promising candidate for such a treatment. However, this requires retention of the entire decay chain at the target site, preventing the creation of freely circulating alpha-emitters that reduce therapeutic effect and increase toxicity to non-target tissues. Two major challenges to 225Ac pharmaceutical development exist: insufficient global supply, and the difficulty of preventing toxicity by retaining the entire decay chain at the target site. While TRIUMF works towards large-scale (C i amounts) production of 225Ac, we already use our Isotope Separation On-Line facility to provide small (< 1 mCi) quantities for in-house chemistry and imaging research that aims to improve and assess 225Ac radiopharmaceutical targeting. This presentation provides an overview of this research program and the journey of 225Ac from the beamline to the scanner. This research is funded by the Natural Sciences and Engineering Research Council of Canada.

  4. TWO-SPEED DEVICE

    DOEpatents

    Brunson, G.S. Jr.

    1961-04-01

    A two-speed device is described comprising a two-part stop engageable with a follower. The two-pant stop comprises first and second members in threaded engagement with each other. The first member is restrained against rotation but is free to move longitudinally, and the second member is free to move arially and rotatively. Means are provided to impart rotation to the second member. The follower is engageable first with an end of one member and then with the corresponding end of the other member after some relative longitudinal movement of the members with respect to one another due to the rotation of the second member and the holding of the first member against rotation.

  5. HIGH SPEED CAMERA

    DOEpatents

    Rogers, B.T. Jr.; Davis, W.C.

    1957-12-17

    This patent relates to high speed cameras having resolution times of less than one-tenth microseconds suitable for filming distinct sequences of a very fast event such as an explosion. This camera consists of a rotating mirror with reflecting surfaces on both sides, a narrow mirror acting as a slit in a focal plane shutter, various other mirror and lens systems as well as an innage recording surface. The combination of the rotating mirrors and the slit mirror causes discrete, narrow, separate pictures to fall upon the film plane, thereby forming a moving image increment of the photographed event. Placing a reflecting surface on each side of the rotating mirror cancels the image velocity that one side of the rotating mirror would impart, so as a camera having this short a resolution time is thereby possible.

  6. High speed nozzles task

    NASA Technical Reports Server (NTRS)

    Hamed, Awatef

    1995-01-01

    Supersonic cruise exhaust nozzles for advanced applications are optimized for a high nozzle pressure ratio (NPR) at design supersonic cruise Mach number and altitude. The performance of these nozzles with large expansion ratios are severely degraded for operations at subsonic speeds near sea level for NPR significantly less than the design values. The prediction of over-expanded 2DCD nozzles performance is critical to evaluating the internal losses and to the optimization of the integrated vehicle and propulsion system performance. The reported research work was aimed at validating and assessing existing computational methods and turbulence models for predicting the flow characteristics and nozzle performance at over-expanded conditions. Flow simulations in 2DCD nozzles were performed using five different turbulence models. The results are compared with the experimental data for the wall pressure distribution and thrust and flow coefficients at over-expanded static conditions.

  7. Speeded naming or naming speed? The automatic effect of object speed on performance.

    PubMed

    Ben-Haim, Moshe Shay; Chajut, Eran; Hassin, Ran R; Algom, Daniel

    2015-04-01

    We test the hypothesis that naming an object depicted in a picture and reading aloud an object's name are affected by the object's speed. We contend that the mental representations of everyday objects and situations include their speed, and that the latter influences behavior in instantaneous and systematic ways. An important corollary is that high-speed objects are named faster than low-speed objects, although object speed is irrelevant to the naming task at hand. The results of a series of 7 studies with pictures and words support these predictions.

  8. Improved SCR ac Motor Controller for Battery Powered Urban Electric Vehicles

    NASA Technical Reports Server (NTRS)

    Latos, T. S.

    1982-01-01

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

  9. A Stimulated Raman Scattering CMOS Pixel Using a High-Speed Charge Modulator and Lock-in Amplifier

    PubMed Central

    Lioe, De Xing; Mars, Kamel; Kawahito, Shoji; Yasutomi, Keita; Kagawa, Keiichiro; Yamada, Takahiro; Hashimoto, Mamoru

    2016-01-01

    A complementary metal-oxide semiconductor (CMOS) lock-in pixel to observe stimulated Raman scattering (SRS) using a high speed lateral electric field modulator (LEFM) for photo-generated charges and in-pixel readout circuits is presented. An effective SRS signal generated after the SRS process is very small and needs to be extracted from an extremely large offset due to a probing laser signal. In order to suppress the offset components while amplifying high-frequency modulated small SRS signal components, the lock-in pixel uses a high-speed LEFM for demodulating the SRS signal, resistor-capacitor low-pass filter (RC-LPF) and switched-capacitor (SC) integrator with a fully CMOS differential amplifier. AC (modulated) components remained in the RC-LPF outputs are eliminated by the phase-adjusted sampling with the SC integrator and the demodulated DC (unmodulated) components due to the SRS signal are integrated over many samples in the SC integrator. In order to suppress further the residual offset and the low frequency noise (1/f noise) components, a double modulation technique is introduced in the SRS signal measurements, where the phase of high-frequency modulated laser beam before irradiation of a specimen is modulated at an intermediate frequency and the demodulation is done at the lock-in pixel output. A prototype chip for characterizing the SRS lock-in pixel is implemented and a successful operation is demonstrated. The reduction effects of residual offset and 1/f noise components are confirmed by the measurements. A ratio of the detected small SRS to offset a signal of less than 10−5 is experimentally demonstrated, and the SRS spectrum of a Benzonitrile sample is successfully observed. PMID:27089339

  10. A Stimulated Raman Scattering CMOS Pixel Using a High-Speed Charge Modulator and Lock-in Amplifier.

    PubMed

    Lioe, De Xing; Mars, Kamel; Kawahito, Shoji; Yasutomi, Keita; Kagawa, Keiichiro; Yamada, Takahiro; Hashimoto, Mamoru

    2016-04-13

    A complementary metal-oxide semiconductor (CMOS) lock-in pixel to observe stimulated Raman scattering (SRS) using a high speed lateral electric field modulator (LEFM) for photo-generated charges and in-pixel readout circuits is presented. An effective SRS signal generated after the SRS process is very small and needs to be extracted from an extremely large offset due to a probing laser signal. In order to suppress the offset components while amplifying high-frequency modulated small SRS signal components, the lock-in pixel uses a high-speed LEFM for demodulating the SRS signal, resistor-capacitor low-pass filter (RC-LPF) and switched-capacitor (SC) integrator with a fully CMOS differential amplifier. AC (modulated) components remained in the RC-LPF outputs are eliminated by the phase-adjusted sampling with the SC integrator and the demodulated DC (unmodulated) components due to the SRS signal are integrated over many samples in the SC integrator. In order to suppress further the residual offset and the low frequency noise (1/f noise) components, a double modulation technique is introduced in the SRS signal measurements, where the phase of high-frequency modulated laser beam before irradiation of a specimen is modulated at an intermediate frequency and the demodulation is done at the lock-in pixel output. A prototype chip for characterizing the SRS lock-in pixel is implemented and a successful operation is demonstrated. The reduction effects of residual offset and 1/f noise components are confirmed by the measurements. A ratio of the detected small SRS to offset a signal of less than 10(-)⁵ is experimentally demonstrated, and the SRS spectrum of a Benzonitrile sample is successfully observed.

  11. Non-intrusive speed sensor

    NASA Technical Reports Server (NTRS)

    Wyett, L.

    1986-01-01

    In Phase I of the Non-Intrusive Speed Sensor program, a computerized literature search was performed to identify candidate technologies for remote, non-intrusive speed sensing applications in Space Shuttle Main Engine (SSME) turbopumps. The three most promising technologies were subjected to experimental evaluation to quantify their performance characteristics under the harsh environmental requirements within the turbopumps. Although the infrared and microwave approaches demonstrated excellent cavitation immunity in laboratory tests, the variable-source magnetic speed sensor emerged as the most viable approach. Preliminary design of this speed sensor encountered no technical obstacles and resulted in viable and feasible speed nut, sensor housing, and sensor coil designs. Phase II of this program developed the variable-source magnetic speed sensor through the detailed design task and guided the design into breadboard fabrication. The speed sensor and its integral speed nut were evaluated at both unit and system level testing. The final room-temperature and cryogenic spin testing of the hardware demonstrated that the sensor was capable of generating sufficient output signal to enable remote speed sensing from 1500 to 40000 rpm over a speed nut/sensor separation of 3.5 inches.

  12. Numerical simulation of ac plasma arc thermodynamics

    NASA Astrophysics Data System (ADS)

    Wu, Han-Ming; Carey, G. F.; Oakes, M. E.

    1994-05-01

    A mathematical model and approximate analysis for the energy distribution of an ac plasma arc with a moving boundary is developed. A simplified electrical conductivity function is assumed so that the dynamic behavior of the arc may be determined, independent of the gas type. The model leads to a reduced set of non-linear partial differential equations which governs the quasi-steady ac arc. This system is solved numerically and it is found that convection plays an important role, not only in the temperature distribution, but also in arc disruptions. Moreover, disruptions are found to be influenced by convection only for a limited frequency range. The results of the present studies are applicable to the frequnecy range of 10-10(exp 2) Hz which includes most industry ac arc frequencies.

  13. Numerical Simulation of AC Plasma Arc Thermodynamics

    NASA Astrophysics Data System (ADS)

    Wu, Han-Ming; Carey, G. F.; Oakes, M. E.

    1994-05-01

    A mathematical model and approximate analysis for the energy distribution of an ac plasma arc with a moving boundary is developed. A simplified electrical conductivity function is assumed so that the dynamic behavior of the arc may be determined, independent of the gas type. The model leads to a reduced set of non-linear partial differential equations which governs the quasi-steady ac arc. This system is solved numerically and it is found that convection plays an important role, not only in the temperature distribution, but also in arc disruptions. Moreover, disruptions are found to be influenced by convection only for a limited frequency range. The results of the present studies are applicable to the frequency range of 10-102 Hz which includes most industry ac arc frequencies.

  14. Ecophysiology of invasive plants: osmotic adjustment and antioxidants.

    PubMed

    Pintó-Marijuan, Marta; Munné-Bosch, Sergi

    2013-12-01

    Current research into plant invasiveness often attempts to predict the effect of invasions under future climate change, but most studies only focus on ecological aspects. Understanding ecophysiological responses by characterizing physiological markers such as osmotic adjustment or antioxidant protection indicators will help us to project future invasiveness patterns. In this opinion article, we highlight how the information from physiological measurements can be incorporated into effective management strategies. Furthermore, we propose how combining research strategies of physiologists and ecologists could speed up our understanding of the advantageous mechanisms adopted by invasive species. We suggest that a combined approach would also be of considerable benefit for the development of effective governmental biodiversity conservation policies.

  15. Fully digital controlled A.C. servo engraving machine based on DEC4DA

    NASA Astrophysics Data System (ADS)

    Shu, Zhibing; Chen, Xianfeng; Zhang, Hairong; Huang, Yiqun; Yan, Caizhong

    2005-12-01

    A novel engraving machine (NUT-1A) is presented, in which fully digital controlled AC system based on DEC4DA was used to improve the machining precision and sensitivity. This engraving machine was constructed around AC servo motor with encoder, controlled by a servo motor control card - DEC4DA. As the upper unit of AC servo motor, DEC4DA was a numerical control generator, which received pulses form CPU by ISA bus, and these pulses were amplified and converted to drive AC servo actuator. This novel engraving machine can achieve a higher positioning accuracy of +/-0.01mm and positioning repetition of +/-0.005mm, and its resolution is 0.001mm/0.0001mm. Moreover, because of multi-closed loops were used in the system, the steady and transient performances are more excellent. This system ensures a much quicker current regulation in closed-loop operation, of acceleration and braking in both directions, as well as stable speed characteristics. Amplifier boards are protected against excessive current, excessive temperature and short circuiting of the motor supply cables.

  16. Inflation Adjustments for Defense Acquisition

    DTIC Science & Technology

    2014-10-01

    Harmon Daniel B. Levine Stanley A. Horowitz, Project Leader INSTITUTE FOR DEFENSE ANALYSES 4850 Mark Center Drive Alexandria, Virginia 22311-1882 Approved...T U T E F O R D E F E N S E A N A L Y S E S IDA Document D-5112 Inflation Adjustments for Defense Acquisition Bruce R. Harmon Daniel B. Levine...might do a better job? The focus of the study is on aircraft procurement. By way of terminology , “cost index,” “price index,” and “deflator” are used

  17. Adjustable extender for instrument module

    DOEpatents

    Sevec, J.B.; Stein, A.D.

    1975-11-01

    A blank extender module used to mount an instrument module in front of its console for repair or test purposes has been equipped with a rotatable mount and means for locking the mount at various angles of rotation for easy accessibility. The rotatable mount includes a horizontal conduit supported by bearings within the blank module. The conduit is spring-biased in a retracted position within the blank module and in this position a small gear mounted on the conduit periphery is locked by a fixed pawl. The conduit and instrument mount can be pulled into an extended position with the gear clearing the pawl to permit rotation and adjustment of the instrument.

  18. Focused Mission High Speed Combatant

    DTIC Science & Technology

    2003-05-09

    hull types to determine which hull type best meets the requirements for the Focused Mission High Speed Combatant. The first step in the analysis...MAPC, uses parametric models and scaling to create high level designs of various hull types. The inputs are desired speed , range, payload, sea state...reached 10 SWATH vessels exhibit superior seakeeping at near zero speed compared to other hull forms 5 Assumes 2 equal-sized GE Gas Turbines 11

  19. Pay as You Speed, ISA with incentive for not speeding: results and interpretation of speed data.

    PubMed

    Lahrmann, Harry; Agerholm, Niels; Tradisauskas, Nerius; Berthelsen, Kasper K; Harms, Lisbeth

    2012-09-01

    To simulate a market introduction of Intelligent Speed Adaptation (ISA) and to study the effect of a Pay as You Speed (PAYS) concept, a field trial with 153 drivers was conducted during 2007-2009. The participants drove under PAYS conditions for a shorter or a longer period. The PAYS concept consisted of informative ISA linked with economic incentive for not speeding, measured through automatic count of penalty points whenever the speed limit was exceeded. The full incentive was set to 30% of a participant's insurance premium. The participants were exposed to different treatments, with and without incentive crossed with informative ISA present or absent. The results showed that ISA is an efficient tool for reducing speeding particularly on rural roads. The analysis of speed data demonstrated that the proportion of distance driven above the speed where the ISA equipment responded (PDA) was a sensitive measure for reflecting the effect of ISA, whereas mean free flow speed and the 85th percentile speed, were less sensitive to ISA effects. The PDA increased a little over time but still remained at a low level; however, when ISA was turned off, the participants' speeding relapsed to the baseline level. Both informative ISA and incentive ISA reduced the PDA, but there was no statistically significant interaction. Informative reduced it more than the incentive.

  20. Two speed axle assembly

    SciTech Connect

    Heine, C.F.; Krisher, J.A.; Pifer, R.L.

    1988-10-04

    This patent describes a two speed axle assembly comprising an input sun gear, an output sun gear, a plant carrier mounted for rotation about the input and output sun gears, at least one compound planetary gear rotatably mounted on the planet carrier and drivingly connected to the input sun gear and the output sun gear, first clutch means for selectively locking the planet carrier relative to the input sun gear for rotation therewith including means normally loading the first clutch means whereby the planet carrier rotates the input sun gear, second clutch means for alternatively locking the planet carrier against rotation whereby the compound planet gear rotates on the planet carrier in response to rotation of the input sun gear, and inflatable bladder means adapted when selectively inflated to load the second clutch means and simultaneously unload the normally loaded first clutch means whereby the planet carrier is unlocked relative to the input sun gear and locked against rotation, including means selectively supplying hydraulic fluid under pressure to the bladder means, means supplying hydraulic fluid comprising accumulator means, pump means remote from the axle assembly for pressurizing the hydraulic fluid and maintaining a supply of the fluid under at least a minimum pressure in the accumulator means, and valve means for selectively admitting the pressurized fluid from the accumulator means to the bladder means to inflate the bladder means and relieving the pressure to deflate the bladder means.

  1. Neutron Speed Echo Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ioffe, A.

    Neutron speed echo (NSPE) technique is in a way a generalization of the neutron spin echo (NSE) technique. Similar to NSE spectrometers, the resolution of such NSPE spectrometer is extremely high and is not connected with the monochromatization of the incoming beam. However, in contrast to NSE spectrometers, the operation of proposed spectrometer does not necessarily require a polarized neutron beam. Such decoupling the polarization and the resolution is in clear contrast to NSE technique. Because the resolution of a NSPE spectrometer can be a few orders higher than the resolution of NSE spectrometers, one can achieve the energy resolution of about 10-14 eV by the use of ultra cold neutrons; a fact that can be used in some fundamental physics experiments. Though the scattering on the sample impose limitations on the resolution of a NSPE spectrometer, the use of the proposed technique in a low-resolution mode can be useful in the combination with triple-axis spectrometers and allow for the significant improvement of their energy resolution, however, without the use of polarized neutrons. This fact opens new possibilities for the study of magnetic phenomena in solids, where the NSE method is principally not applicable because of the neutron precession in the sample, especially by combining polarization analysis with high-resolution spectroscopy. The proposed technique also allows for an easy implementation of the principle of the NSE focusing, when the resolution ellipse is aligned along a dispersion curve.

  2. High speed civil transport

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This report discusses the design and marketability of a next generation supersonic transport. Apogee Aeronautics Corporation has designated its High Speed Civil Transport (HSCT): Supercruiser HS-8. Since the beginning of the Concorde era, the general consensus has been that the proper time for the introduction of a next generation Supersonic Transport (SST) would depend upon the technical advances made in the areas of propulsion (reduction in emissions) and material composites (stronger, lighter materials). It is believed by many in the aerospace industry that these beforementioned technical advances lie on the horizon. With this being the case, this is the proper time to begin the design phase for the next generation HSCT. The design objective for a HSCT was to develop an aircraft that would be capable of transporting at least 250 passengers with baggage at a distance of 5500 nmi. The supersonic Mach number is currently unspecified. In addition, the design had to be marketable, cost effective, and certifiable. To achieve this goal, technical advances in the current SST's must be made, especially in the areas of aerodynamics and propulsion. As a result of these required aerodynamic advances, several different supersonic design concepts were reviewed.

  3. Negative hydrogen ion beam extraction from an AC heated cathode driven Bernas-type ion source

    SciTech Connect

    Okano, Y.; Miyamoto, N.; Kasuya, T.; Wada, M.

    2015-04-08

    A plasma grid structure was installed to a Bernas-type ion source used for ion implantation equipment. A negative hydrogen (H{sup −}) ion beam was extracted by an AC driven ion source by adjusting the bias to the plasma grid. The extracted electron current was reduced by positively biasing the plasma grid, while an optimum plasma grid bias voltage for negative ion beam extraction was found to be positive 3 V with respect to the arc chamber. Source operations with AC cathode heating show extraction characteristics almost identical to that with DC cathode heating, except a minute increase in H{sup −} current at higher frequency of cathode heating current.

  4. The correction of linear lattice gradient errors using an AC dipole

    SciTech Connect

    Wang,G.; Bai, M.; Litvinenko, V.N.; Satogata, T.

    2009-05-04

    Precise measurement of optics from coherent betatron oscillations driven by ac dipoles have been demonstrated at RHIC and the Tevatron. For RHIC, the observed rms beta-beat is about 10%. Reduction of beta-beating is an essential component of performance optimization at high energy colliders. A scheme of optics correction was developed and tested in the RHIC 2008 run, using ac dipole optics for measurement and a few adjustable trim quadruples for correction. In this scheme, we first calculate the phase response matrix from the. measured phase advance, and then apply singular value decomposition (SVD) algorithm to the phase response matrix to find correction quadruple strengths. We present both simulation and some preliminary experimental results of this correction.

  5. Locomotion speeds of various dinosaurs

    NASA Astrophysics Data System (ADS)

    Dougherty, Mary; Lee, Scott

    2009-03-01

    Most students have a passing curiosity about dinosaurs. Piquing this interest is an excellent tool to engage students. A methodology for estimating the locomotion speed of an animal based upon their footprint tracks is developed. Using this technique, an analysis of the locomotion speeds of various dinosaurs is performed. The tracks studied include 28 theropods (meat-eating dinosaurs), 23 sauropods (the ``long-necked'' herbivores), 28 non-armored, non-sauropod herbivores and 10 armored, non-sauropod herbivores. The theropods show the fastest locomotion speed as well as the greatest variety of speeds while the armored dinosaurs are the slowest.

  6. Locomotion Speeds of Various Dinosaurs

    NASA Astrophysics Data System (ADS)

    Dougherty, M. T.; Lee, S. A.

    2009-04-01

    A methodology for estimating the locomotion speed of an animal based upon their footprint tracks is developed. Using this technique, an analysis of the locomotion speeds of various dinosaurs is performed. The tracks studied include 28 theropods (meat-eating dinosaurs), 23 sauropods (the ``long-necked'' herbivores), 28 non-armored, non-sauropod herbivores and 10 armored, non-sauropod herbivores. The theropods show the fastest locomotion speed as well as the greatest variety of speeds while the armored dinosaurs are the slowest.

  7. Power quality control and design of power converter for variable-speed wind energy conversion system with permanent-magnet synchronous generator.

    PubMed

    Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin

    2013-01-01

    The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%.

  8. Power Quality Control and Design of Power Converter for Variable-Speed Wind Energy Conversion System with Permanent-Magnet Synchronous Generator

    PubMed Central

    Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin

    2013-01-01

    The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%. PMID:24453905

  9. High-Speed Schlieren Movies of Decelerators at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    1960-01-01

    High-Speed Schlieren Movies of Decelerators at Supersonic Speeds. Tests were conducted on several types of porous parachutes, a paraglider, and a simulated retrorocket. Mach numbers ranged from 1.8-3.0, porosity from 20-80 percent, and camera speeds from 1680-3000 feet per second (fps) in trials with porous parachutes. Trials of reefed parachutes were conducted at Mach number 2.0 and reefing of 12-33 percent at camera speeds of 600 fps. A flexible parachute with an inflatable ring in the periphery of the canopy was tested at Reynolds number 750,000 per foot, Mach number 2.85, porosity of 28 percent, and camera speed of 36oo fps. A vortex-ring parachute was tested at Mach number 2.2 and camera speed of 3000 fps. The paraglider, with a sweepback of 45 degrees at an angle of attack of 45 degrees was tested at Mach number 2.65, drag coefficient of 0.200, and lift coefficient of 0.278 at a camera speed of 600 fps. A cold air jet exhausting upstream from the center of a bluff body was used to simulate a retrorocket. The free-stream Mach number was 2.0, free-stream dynamic pressure was 620 lb/sq ft, jet-exit static pressure ratio was 10.9, and camera speed was 600 fps. [Entire movie available on DVD from CASI as Doc ID 20070030973. Contact help@sti.nasa.gov

  10. Speed Listening: Exploring an Analogue of Speed Reading. Final Report.

    ERIC Educational Resources Information Center

    Wallace, William P.

    To determine whether the impressive rates for speed reading (e.g., 500 words per minute) can be approximated in speed listening, two experiments compared the comprehension level of material heard at a normal speaking rate with that heard at accelerated rates. In the first experiment, the major demonstration experiment, three groups of college…

  11. Clock Controller For Ac Self-Timing Analysis Of Logic System

    DOEpatents

    Lo, Tinchee; Flanagan, John D.

    2004-05-18

    A clock controller and clock generating method are provided for AC self-test timing analysis of a logic system. The controller includes latch circuitry which receives a DC input signal at a data input, and a pair of continuous out-of-phase clock signals at capture and launch clock inputs thereof. The latch circuitry outputs two overlapping pulses responsive to the DC input signal going high. The two overlapping pulses are provided to waveform shaper circuitry which produces therefrom two non-overlapping pulses at clock speed of the logic system to be tested. The two non-overlapping pulses are a single pair of clock pulses which facilitate AC self-test timing analysis of the logic system.

  12. Progress on advanced dc and ac induction drives for electric vehicles

    NASA Technical Reports Server (NTRS)

    Schwartz, H. J.

    1982-01-01

    Progress is reported in the development of complete electric vehicle propulsion systems, and the results of tests on the Road Load Simulator of two such systems representative of advanced dc and ac drive technology are presented. One is the system used in the DOE's ETV-1 integrated test vehicle which consists of a shunt wound dc traction motor under microprocessor control using a transistorized controller. The motor drives the vehicle through a fixed ratio transmission. The second system uses an ac induction motor controlled by transistorized pulse width modulated inverter which drives through a two speed automatically shifted transmission. The inverter and transmission both operate under the control of a microprocessor. The characteristics of these systems are also compared with the propulsion system technology available in vehicles being manufactured at the inception of the DOE program and with an advanced, highly integrated propulsion system upon which technology development was recently initiated.

  13. Comparative performance evaluation of advanced AC and DC EV propulsion systems

    NASA Astrophysics Data System (ADS)

    MacDowall, R. D.; Crumley, R. L.

    Idaho National Engineering Laboratory (INEL) evaluates EV propulsion systems and components for the U.S. Department of Energy (DOE) Electric and Hybrid Vehicle (EHV) Program. In this study, experimental data were used to evaluate the relative performances of the benchmark Chrysler/GE ETV-1 DC and the Ford/GE First Generation Single-Shaft AC (ETX-I) propulsion systems. Tests were conducted on the INEL's chassis dynamometer using identical aerodynamic and rolling resistance road-load coefficients and vehicle test weights. The results allowed a direct comparison of selected efficiency and performance characteristics for the two propulsion system technologies. The ETX-I AC system exhibited slightly lower system efficiency during constant speed testing than the ETV-1 DC propulsion system.

  14. The Relationship between Processing Speed and Regional White Matter Volume in Healthy Young People

    PubMed Central

    Magistro, Daniele; Takeuchi, Hikaru; Nejad, Keyvan Kashkouli; Taki, Yasuyuki; Sekiguchi, Atsushi; Nouchi, Rui; Kotozaki, Yuka; Nakagawa, Seishu; Miyauchi, Carlos Makoto; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Hashizume, Hiroshi; Sassa, Yuko; Kawashima, Ryuta

    2015-01-01

    Processing speed is considered a key cognitive resource and it has a crucial role in all types of cognitive performance. Some researchers have hypothesised the importance of white matter integrity in the brain for processing speed; however, the relationship at the whole-brain level between white matter volume (WMV) and processing speed relevant to the modality or problem used in the task has never been clearly evaluated in healthy people. In this study, we used various tests of processing speed and Voxel-Based Morphometry (VBM) analyses, it is involves a voxel-wise comparison of the local volume of gray and white, to assess the relationship between processing speed and regional WMV (rWMV). We examined the association between processing speed and WMV in 887 healthy young adults (504 men and 383 women; mean age, 20.7 years, SD, 1.85). We performed three different multiple regression analyses: we evaluated rWMV associated with individual differences in the simple processing speed task, word–colour and colour–word tasks (processing speed tasks with words) and the simple arithmetic task, after adjusting for age and sex. The results showed a positive relationship at the whole-brain level between rWMV and processing speed performance. In contrast, the processing speed performance did not correlate with rWMV in any of the regions examined. Our results support the idea that WMV is associated globally with processing speed performance regardless of the type of processing speed task. PMID:26397946

  15. Adjusting the Contour of Reflector Panels

    NASA Technical Reports Server (NTRS)

    Palmer, W. B.; Giebler, M. M.

    1984-01-01

    Postfabrication adjustment of contour of panels for reflector, such as parabolic reflector for radio antennas, possible with simple mechanism consisting of threaded stud, two nuts, and flexure. Contours adjusted manually.

  16. 48 CFR 1450.103 - Contract adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract adjustments. 1450.103 Section 1450.103 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR CONTRACT... Contract adjustments....

  17. First Year Adjustment in the Secondary School.

    ERIC Educational Resources Information Center

    Loosemore, Jean Ann

    1978-01-01

    This study investigated the relationship between adjustment to secondary school and 17 cognitive and noncognitive variables, including intelligence (verbal and nonverbal reasoning), academic achievement, extraversion-introversion, stable/unstable, social adjustment, endeavor, age, sex, and school form. (CP)

  18. Swimming speed and foraging strategies of northern elephant seals

    NASA Astrophysics Data System (ADS)

    Hassrick, Jason L.; Crocker, Daniel E.; Zeno, Ramona L.; Blackwell, Susanna B.; Costa, Daniel P.; Le Boeuf, Burney J.

    2007-02-01

    We investigated swimming speed, a key variable in both the management of oxygen stores and foraging strategies, and its relationship to diving behaviour in northern elephant seals , Mirounga angustirostris. Swimming speed significantly reduced the dive duration and time at depth for presumed foraging dives, but increased with dive depth. This suggests that the extended duration of deep dives is made possible by physiological adjustments and not by changes in swimming speed or effort. Swimming speeds were similar across sex and age classes despite different predicted minimum cost of transport speeds. All seals exhibited characteristic dive shapes and swimming speed patterns that support their putative functions, but two-dimensional dive shapes and swimming angles varied between sexes and age classes. Mean dive angles on descent were markedly shallow, suggesting use of negative buoyancy to cover horizontal distance while diving. Buoyancy also appeared to affect two-dimensional dive shapes and ability to use extended gliding behaviours between surface and deep foraging zones. Significant differences in diving behaviour between sexes and between young and adult females were evident for various phases of the dive cycle, potentially resulting from physical constraints or differences in dive functionality.

  19. AC Losses of Prototype HTS Transmission Cables

    SciTech Connect

    Demko, J.A.; Dresner, L.; Hughey, R.L.; Lue, J.W.; Olsen, S.K.; Sinha, U.; Tolbert, J.C.

    1998-09-13

    Since 1995 Southwire Company and Oak Ridge National Laboratory (ORNL) have jointly designed, built, and tested nine, l-m long, high temperature superconducting (HTS) transmission cable prototypes. This paper summarizes the AC loss measurements of five of the cables not reported elsewhere, and compares the losses with each other and with theory developed by Dresner. Losses were measured with both a calorimetric and an electrical technique. Because of the broad resistive transition of the HTS tapes, the cables can be operated stably beyond their critical currents. The AC losses were measured in this region as well as below critical currents. Dresner's theory takes into account the broad resistive transition of the HTS tapes and calculates the AC losses both below and above the critical current. The two sets of AC 10SS data agree with each other and with the theory quite welL In particular, at low currents of incomplete penetration, the loss data agree with the theoretical prediction of hysteresis loss based on only the outer two Iayers carrying the total current.

  20. AC power generation from microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Lobo, Fernanda Leite; Wang, Heming; Forrestal, Casey; Ren, Zhiyong Jason

    2015-11-01

    Microbial fuel cells (MFCs) directly convert biodegradable substrates to electricity and carry good potential for energy-positive wastewater treatment. However, the low and direct current (DC) output from MFC is not usable for general electronics except small sensors, yet commercial DC-AC converters or inverters used in solar systems cannot be directly applied to MFCs. This study presents a new DC-AC converter system for MFCs that can generate alternating voltage in any desired frequency. Results show that AC power can be easily achieved in three different frequencies tested (1, 10, 60 Hz), and no energy storage layer such as capacitors was needed. The DC-AC converter efficiency was higher than 95% when powered by either individual MFCs or simple MFC stacks. Total harmonic distortion (THD) was used to investigate the quality of the energy, and it showed that the energy could be directly usable for linear electronic loads. This study shows that through electrical conversion MFCs can be potentially used in household electronics for decentralized off-grid communities.

  1. Organic magnetoresistance under resonant ac drive

    NASA Astrophysics Data System (ADS)

    Roundy, R. C.; Raikh, M. E.

    2013-09-01

    Motivated by a recent experiment, we develop a theory of organic magnetoresistance (OMAR) in the presence of a resonant ac drive. To this end, we perform a thorough analysis of the dynamics of ac-driven electron-hole polaron pair in magnetic field, which is a sum of external and random hyperfine fields. Resonant ac drive affects the OMAR by modifying the singlet content of the eigenmodes. This, in turn, leads to the change of recombination rate, and ultimately, to the change of the spin-blocking that controls the current. Our analysis demonstrates that, upon increasing the drive amplitude, the blocking eigenmodes of the triplet type acquire a singlet admixture and become unblocking. Most surprisingly, the opposite process goes in parallel: new blocking modes emerge from nonblocking precursors as the drive increases. These emergent blocking modes are similar to subradiant modes in the Dicke effect. A nontrivial evolution of eigenmodes translates into a nontrivial behavior of OMAR with the amplitude of the ac drive: it is initially linear, then passes through a maximum, drops, and finally saturates.

  2. A dry-cooled AC quantum voltmeter

    NASA Astrophysics Data System (ADS)

    Schubert, M.; Starkloff, M.; Peiselt, K.; Anders, S.; Knipper, R.; Lee, J.; Behr, R.; Palafox, L.; Böck, A. C.; Schaidhammer, L.; Fleischmann, P. M.; Meyer, H.-G.

    2016-10-01

    The paper describes a dry-cooled AC quantum voltmeter system operated up to kilohertz frequencies and 7 V rms. A 10 V programmable Josephson voltage standard (PJVS) array was installed on a pulse tube cooler (PTC) driven with a 4 kW air-cooled compressor. The operating margins at 70 GHz frequencies were investigated in detail and found to exceed 1 mA Shapiro step width. A key factor for the successful chip operation was the low on-chip power consumption of 65 mW in total. A thermal interface between PJVS chip and PTC cold stage was used to avoid a significant chip overheating. By installing the cryocooled PJVS array into an AC quantum voltmeter setup, several calibration measurements of dc standards and calibrator ac voltages up to 2 kHz frequencies were carried out to demonstrate the full functionality. The results are discussed and compared to systems with standard liquid helium cooling. For dc voltages, a direct comparison measurement between the dry-cooled AC quantum voltmeter and a liquid-helium based 10 V PJVS shows an agreement better than 1 part in 1010.

  3. Generalized adjustment by least squares ( GALS).

    USGS Publications Warehouse

    Elassal, A.A.

    1983-01-01

    The least-squares principle is universally accepted as the basis for adjustment procedures in the allied fields of geodesy, photogrammetry and surveying. A prototype software package for Generalized Adjustment by Least Squares (GALS) is described. The package is designed to perform all least-squares-related functions in a typical adjustment program. GALS is capable of supporting development of adjustment programs of any size or degree of complexity. -Author

  4. 49 CFR 393.53 - Automatic brake adjusters and brake adjustment indicators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... brake adjustment indicators. (a) Automatic brake adjusters (hydraulic brake systems). Each commercial motor vehicle manufactured on or after October 20, 1993, and equipped with a hydraulic brake...

  5. Models of Speed Discrimination

    NASA Technical Reports Server (NTRS)

    1997-01-01

    visual search for the detection of speed deviation. 2. Perception of moving objects. 3. Exploring the role of eye movements in various visual tasks.

  6. An Adaptive Speed Control System for Micro Electro Discharge Machining

    NASA Astrophysics Data System (ADS)

    Yeo, S. H.; Aligiri, E.; Tan, P. C.; Zarepour, H.

    2009-11-01

    The integration of the state-of-the-art monitoring and adaptive control technologies can substantially improve the performance of EDM process. This paper reports the development of an adaptive speed control system for micro EDM which demands a higher level of accuracy. Monitoring of the machining state is conducted during the machining process so that the conditions are analysed continuously. Various schemes for the machining state are used for decision making. For instance, upon recognition of abnormal discharges, the developed adaptive speed control system would adjust the electrode feeding speed in an attempt to correct the machining state. Experimental verification shows that the proposed system can improve the machining time by more than 50%. In addition, a more accurate machined feature can be produced as compared to traditional EDM servo control systems.

  7. Motivating inhibition - reward prospect speeds up response cancellation.

    PubMed

    Boehler, Carsten N; Hopf, Jens-Max; Stoppel, Christian M; Krebs, Ruth M

    2012-12-01

    Reward prospect has been demonstrated to facilitate various cognitive and behavioral operations, particularly by enhancing the speed and vigor of processes linked to approaching reward. Studies in this domain typically employed task regimes in which participants' overt responses are facilitated by prospective rewards. In contrast, we demonstrate here that even the cancellation of a motor response can be accelerated by reward prospect, thus signifying reward-related benefits on restraint rather than approach behavior. Importantly, this facilitation occurred independent of strategy-related adjustments of response speed, which are known to systematically distort the estimation of response-cancellation speed. The fact that motivational factors can indeed facilitate response inhibition is not only relevant for understanding how motivation and response inhibition interact in healthy participants but also for work on various patient groups that display response-inhibition deficits, suggesting that core differences in the ability to inhibit motor responses have to be differentiated from motivational factors.

  8. 7 CFR 1744.64 - Budget adjustment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 11 2014-01-01 2014-01-01 false Budget adjustment. 1744.64 Section 1744.64... Disbursement of Funds § 1744.64 Budget adjustment. (a) If more funds are required than are available in a budget account, the borrower may request RUS's approval of a budget adjustment to use funds from...

  9. 7 CFR 1744.64 - Budget adjustment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 11 2012-01-01 2012-01-01 false Budget adjustment. 1744.64 Section 1744.64... Disbursement of Funds § 1744.64 Budget adjustment. (a) If more funds are required than are available in a budget account, the borrower may request RUS's approval of a budget adjustment to use funds from...

  10. 7 CFR 1744.64 - Budget adjustment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 11 2013-01-01 2013-01-01 false Budget adjustment. 1744.64 Section 1744.64... Disbursement of Funds § 1744.64 Budget adjustment. (a) If more funds are required than are available in a budget account, the borrower may request RUS's approval of a budget adjustment to use funds from...

  11. 7 CFR 1744.64 - Budget adjustment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 11 2011-01-01 2011-01-01 false Budget adjustment. 1744.64 Section 1744.64... Disbursement of Funds § 1744.64 Budget adjustment. (a) If more funds are required than are available in a budget account, the borrower may request RUS's approval of a budget adjustment to use funds from...

  12. 7 CFR 1744.64 - Budget adjustment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Budget adjustment. 1744.64 Section 1744.64... Disbursement of Funds § 1744.64 Budget adjustment. (a) If more funds are required than are available in a budget account, the borrower may request RUS's approval of a budget adjustment to use funds from...

  13. 24 CFR 5.611 - Adjusted income.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Adjusted income. 5.611 Section 5... Serving Persons with Disabilities: Family Income and Family Payment; Occupancy Requirements for Section 8 Project-Based Assistance Family Income § 5.611 Adjusted income. Adjusted income means annual income...

  14. 24 CFR 5.611 - Adjusted income.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Adjusted income. 5.611 Section 5... Serving Persons with Disabilities: Family Income and Family Payment; Occupancy Requirements for Section 8 Project-Based Assistance Family Income § 5.611 Adjusted income. Adjusted income means annual income...

  15. 19 CFR 201.205 - Salary adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Salary adjustments. 201.205 Section 201.205 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION Debt Collection § 201.205 Salary adjustments. Any negative adjustment to pay arising out of an employee's...

  16. 19 CFR 201.205 - Salary adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 3 2011-04-01 2011-04-01 false Salary adjustments. 201.205 Section 201.205 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION Debt Collection § 201.205 Salary adjustments. Any negative adjustment to pay arising out of an employee's...

  17. 12 CFR 313.55 - Salary adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 4 2011-01-01 2011-01-01 false Salary adjustments. 313.55 Section 313.55 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION PROCEDURE AND RULES OF PRACTICE PROCEDURES FOR CORPORATE DEBT COLLECTION Salary Offset § 313.55 Salary adjustments. Any negative adjustment to pay...

  18. 12 CFR 313.55 - Salary adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Salary adjustments. 313.55 Section 313.55 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION PROCEDURE AND RULES OF PRACTICE PROCEDURES FOR CORPORATE DEBT COLLECTION Salary Offset § 313.55 Salary adjustments. Any negative adjustment to pay...

  19. 12 CFR 313.55 - Salary adjustments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Salary adjustments. 313.55 Section 313.55 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION PROCEDURE AND RULES OF PRACTICE PROCEDURES FOR CORPORATE DEBT COLLECTION Salary Offset § 313.55 Salary adjustments. Any negative adjustment to pay...

  20. 12 CFR 313.55 - Salary adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Salary adjustments. 313.55 Section 313.55 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION PROCEDURE AND RULES OF PRACTICE PROCEDURES FOR CORPORATE DEBT COLLECTION Salary Offset § 313.55 Salary adjustments. Any negative adjustment to pay...

  1. 19 CFR 201.205 - Salary adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 3 2014-04-01 2014-04-01 false Salary adjustments. 201.205 Section 201.205 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION Debt Collection § 201.205 Salary adjustments. Any negative adjustment to pay arising out of an employee's...

  2. 19 CFR 201.205 - Salary adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 3 2012-04-01 2012-04-01 false Salary adjustments. 201.205 Section 201.205 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION Debt Collection § 201.205 Salary adjustments. Any negative adjustment to pay arising out of an employee's...

  3. 19 CFR 201.205 - Salary adjustments.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 3 2013-04-01 2013-04-01 false Salary adjustments. 201.205 Section 201.205 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION Debt Collection § 201.205 Salary adjustments. Any negative adjustment to pay arising out of an employee's...

  4. 12 CFR 313.55 - Salary adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Salary adjustments. 313.55 Section 313.55 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION PROCEDURE AND RULES OF PRACTICE PROCEDURES FOR CORPORATE DEBT COLLECTION Salary Offset § 313.55 Salary adjustments. Any negative adjustment to pay...

  5. 12 CFR 1780.80 - Inflation adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 7 2011-01-01 2011-01-01 false Inflation adjustments. 1780.80 Section 1780.80... DEVELOPMENT RULES OF PRACTICE AND PROCEDURE RULES OF PRACTICE AND PROCEDURE Civil Money Penalty Inflation Adjustments § 1780.80 Inflation adjustments. The maximum amount of each civil money penalty within...

  6. 12 CFR 1780.80 - Inflation adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Inflation adjustments. 1780.80 Section 1780.80... DEVELOPMENT RULES OF PRACTICE AND PROCEDURE RULES OF PRACTICE AND PROCEDURE Civil Money Penalty Inflation Adjustments § 1780.80 Inflation adjustments. The maximum amount of each civil money penalty within...

  7. 34 CFR 36.2 - Penalty adjustment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Penalty adjustment. 36.2 Section 36.2 Education Office of the Secretary, Department of Education ADJUSTMENT OF CIVIL MONETARY PENALTIES FOR INFLATION § 36.2..., Section 36.2—Civil Monetary Penalty Inflation Adjustments Statute Description New maximum (and minimum,...

  8. 34 CFR 36.2 - Penalty adjustment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 1 2011-07-01 2011-07-01 false Penalty adjustment. 36.2 Section 36.2 Education Office of the Secretary, Department of Education ADJUSTMENT OF CIVIL MONETARY PENALTIES FOR INFLATION § 36.2..., Section 36.2—Civil Monetary Penalty Inflation Adjustments Statute Description New maximum (and minimum,...

  9. Speed adaptation as Kalman filtering.

    PubMed

    Barraza, Jose F; Grzywacz, Norberto M

    2008-10-01

    If the purpose of adaptation is to fit sensory systems to different environments, it may implement an optimization of the system. What the optimum is depends on the statistics of these environments. Therefore, the system should update its parameters as the environment changes. A Kalman-filtering strategy performs such an update optimally by combining current estimations of the environment with those from the past. We investigate whether the visual system uses such a strategy for speed adaptation. We performed a matching-speed experiment to evaluate the time course of adaptation to an abrupt velocity change. Experimental results are in agreement with Kalman-modeling predictions for speed adaptation. When subjects adapt to a low speed and it suddenly increases, the time course of adaptation presents two phases, namely, a rapid decrease of perceived speed followed by a slower phase. In contrast, when speed changes from fast to slow, adaptation presents a single phase. In the Kalman-model simulations, this asymmetry is due to the prevalence of low speeds in natural images. However, this asymmetry disappears both experimentally and in simulations when the adapting stimulus is noisy. In both transitions, adaptation now occurs in a single phase. Finally, the model also predicts the change in sensitivity to speed discrimination produced by the adaptation.

  10. 48 CFR Appendixes A-C to Chapter 7 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false A Appendixes A-C to Chapter 7 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT Appendixes A-C to Chapter 7...

  11. 48 CFR Appendixes A-C to Chapter 7 - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false A Appendixes A-C to Chapter 7 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT Appendixes A-C to Chapter 7...

  12. Propeller speed and phase sensor

    NASA Technical Reports Server (NTRS)

    Collopy, Paul D. (Inventor); Bennett, George W. (Inventor)

    1992-01-01

    A speed and phase sensor counterrotates aircraft propellers. A toothed wheel is attached to each propeller, and the teeth trigger a sensor as they pass, producing a sequence of signals. From the sequence of signals, rotational speed of each propeller is computer based on time intervals between successive signals. The speed can be computed several times during one revolution, thus giving speed information which is highly up-to-date. Given that spacing between teeth may not be uniform, the signals produced may be nonuniform in time. Error coefficients are derived to correct for nonuniformities in the resulting signals, thus allowing accurate speed to be computed despite the spacing nonuniformities. Phase can be viewed as the relative rotational position of one propeller with respect to the other, but measured at a fixed time. Phase is computed from the signals.

  13. The need for speed: global optic flow speed influences steering

    PubMed Central

    Kountouriotis, Georgios K.; Mole, Callum D.; Merat, Natasha

    2016-01-01

    How do animals follow demarcated paths? Different species are sensitive to optic flow and one control solution is to maintain the balance of flow symmetry across visual fields; however, it is unclear whether animals are sensitive to changes in asymmetries when steering along curved paths. Flow asymmetries can alter the global properties of flow (i.e. flow speed) which may also influence steering control. We tested humans steering curved paths in a virtual environment. The scene was manipulated so that the ground plane to either side of the demarcated path produced larger or smaller asymmetries in optic flow. Independent of asymmetries and the locomotor speed, the scene properties were altered to produce either faster or slower globally averaged flow speeds. Results showed that rather than being influenced by changes in flow asymmetry, steering responded to global flow speed. We conclude that the human brain performs global averaging of flow speed from across the scene and uses this signal as an input for steering control. This finding is surprising since the demarcated path provided sufficient information to steer, whereas global flow speed (by itself) did not. To explain these findings, existing models of steering must be modified to include a new perceptual variable: namely global optic flow speed. PMID:27293789

  14. Resonant frequency detection and adjustment method for a capacitive transducer with differential transformer bridge

    SciTech Connect

    Hu, M.; Bai, Y. Z. Zhou, Z. B. Li, Z. X.; Luo, J.

    2014-05-15

    The capacitive transducer with differential transformer bridge is widely used in ultra-sensitive space accelerometers due to their simple structure and high resolution. In this paper, the front-end electronics of an inductive-capacitive resonant bridge transducer is analyzed. The analysis result shows that the performance of this transducer depends upon the case that the AC pumping frequency operates at the resonance point of the inductive-capacitive bridge. The effect of possible mismatch between the AC pumping frequency and the actual resonant frequency is discussed, and the theoretical analysis indicates that the output voltage noise of the front-end electronics will deteriorate by a factor of about 3 due to either a 5% variation of the AC pumping frequency or a 10% variation of the tuning capacitance. A pre-scanning method to determine the actual resonant frequency is proposed followed by the adjustment of the operating frequency or the change of the tuning capacitance in order to maintain expected high resolution level. An experiment to verify the mismatching effect and the adjustment method is provided.

  15. Resonant frequency detection and adjustment method for a capacitive transducer with differential transformer bridge

    NASA Astrophysics Data System (ADS)

    Hu, M.; Bai, Y. Z.; Zhou, Z. B.; Li, Z. X.; Luo, J.

    2014-05-01

    The capacitive transducer with differential transformer bridge is widely used in ultra-sensitive space accelerometers due to their simple structure and high resolution. In this paper, the front-end electronics of an inductive-capacitive resonant bridge transducer is analyzed. The analysis result shows that the performance of this transducer depends upon the case that the AC pumping frequency operates at the resonance point of the inductive-capacitive bridge. The effect of possible mismatch between the AC pumping frequency and the actual resonant frequency is discussed, and the theoretical analysis indicates that the output voltage noise of the front-end electronics will deteriorate by a factor of about 3 due to either a 5% variation of the AC pumping frequency or a 10% variation of the tuning capacitance. A pre-scanning method to determine the actual resonant frequency is proposed followed by the adjustment of the operating frequency or the change of the tuning capacitance in order to maintain expected high resolution level. An experiment to verify the mismatching effect and the adjustment method is provided.

  16. AC losses in a HTS coil carrying DC current in AC external magnetic field

    NASA Astrophysics Data System (ADS)

    Ogawa, J.; Zushi, Y.; Fukushima, M.; Tsukamoto, O.; Suzuki, E.; Hirakawa, M.; Kikukawa, K.

    2003-10-01

    We electrically measured AC losses in a Bi2223/Ag-sheathed pancake coil excited by a DC current in AC external magnetic field. Losses in the coil contain two kinds of loss components that are the magnetization losses and dynamic resistance losses. In the measurement, current leads to supply a current to the coil were specially arranged to suppress electromagnetic coupling between the coil current and the AC external magnetic field. A double pick-up coils method was used to suppress a large inductive voltage component contained in voltage signal for measuring the magnetization losses. It was observed that the magnetization losses were dependent on the coil current and that a peak of a curve of the loss factor vs. amplitude of the AC external magnetic field shifted to lower amplitude of the AC magnetic field as the coil current increased. This result suggests the full penetration magnetic field of the coil tape decreases as the coil current increases. The dynamic resistance losses were measured by measuring a DC voltage appearing between the coil terminals. It was observed that the DC voltage appearing in the coil subject to the AC external magnetic field was much larger than that in the coil subject to DC magnetic field.

  17. Evaluation of modern IGBT-modules for hard-switched AC/DC/AC converters

    SciTech Connect

    Blaabjerg, F.; Pedersen, J.K.; Jaeger, U.

    1995-12-31

    The development of IGBT devices is still producing faster devices with lower losses. The applications become more advanced like a complete hard-switched AC/DC/AC converter with almost clean input current and regenerating capabilities. This paper will first focus on a detailed characterization and comparison of eight different IGBT-modules representing state-of-the-art for both PT and NPT technologies. The voltage level of the devices is 1,200V and 1,600V/1,700V. The characterization is done on an advanced measurement system which is briefly described. The characterization is based on static and dynamic tests for both IGBT and the diodes in the IGBT-modules at a junction temperature at 125 C. The comparison is first done directly based on conduction losses and switching losses, and later the measurements are used in a loss model for a complete AC/DC/AC converter application. In the AC/DC/AC converter the power losses are modelled, and different operating conditions are compared like different voltage levels in the DC-link. It is concluded dependent on operation conditions different devices will be preferable, but the high voltage devices have the highest losses even at a high operating voltage.

  18. 7 CFR 1737.31 - Area Coverage Survey (ACS).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 11 2012-01-01 2012-01-01 false Area Coverage Survey (ACS). 1737.31 Section 1737.31... Studies-Area Coverage Survey and Loan Design § 1737.31 Area Coverage Survey (ACS). (a) The Area Coverage Survey (ACS) is a market forecast of service requirements of subscribers in a proposed service area....

  19. 7 CFR 1737.31 - Area Coverage Survey (ACS).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Area Coverage Survey (ACS). 1737.31 Section 1737.31... Studies-Area Coverage Survey and Loan Design § 1737.31 Area Coverage Survey (ACS). (a) The Area Coverage Survey (ACS) is a market forecast of service requirements of subscribers in a proposed service area....

  20. 7 CFR 1737.31 - Area Coverage Survey (ACS).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 11 2013-01-01 2013-01-01 false Area Coverage Survey (ACS). 1737.31 Section 1737.31... Studies-Area Coverage Survey and Loan Design § 1737.31 Area Coverage Survey (ACS). (a) The Area Coverage Survey (ACS) is a market forecast of service requirements of subscribers in a proposed service area....

  1. 7 CFR 1737.31 - Area Coverage Survey (ACS).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 11 2011-01-01 2011-01-01 false Area Coverage Survey (ACS). 1737.31 Section 1737.31... Studies-Area Coverage Survey and Loan Design § 1737.31 Area Coverage Survey (ACS). (a) The Area Coverage Survey (ACS) is a market forecast of service requirements of subscribers in a proposed service area....

  2. 21 CFR 880.5500 - AC-powered patient lift.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered patient lift. 880.5500 Section 880.5500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Devices § 880.5500 AC-powered patient lift. (a) Identification. An AC-powered lift is an...

  3. Methods for Addressing Missing Data with Applications from ACS Exams

    ERIC Educational Resources Information Center

    Brandriet, Alexandra; Holme, Thomas

    2015-01-01

    As part of the ACS Examinations Institute (ACS-EI) national norming process, student performance data sets are collected from professors at colleges and universities from around the United States. Because the data sets are collected on a volunteer basis, the ACS-EI often receives data sets with only students' total scores and without the students'…

  4. Clinical implications of physiological flow adjustment in continuous-flow left ventricular assist devices.

    PubMed

    Tchantchaleishvili, Vakhtang; Luc, Jessica G Y; Cohan, Caitlin M; Phan, Kevin; Hübbert, Laila; Day, Steven W; Massey, H Todd

    2016-11-15

    There is increasing evidence for successful management of end-stage heart failure with continuous-flow left ventricular assist device (CF-LVAD) technology. However, passive flow adjustment at fixed CF-LVAD speed is susceptible to flow balancing issues as well as adverse hemodynamic effects relating to the diminished arterial pulse pressure and flow. With current therapy, flow cannot be adjusted with changes in venous return, which can vary significantly with volume status. This limits the performance and safety of CF-LVAD. Active flow adjustment strategies have been proposed to improve the synchrony between the pump and the native cardiovascular system, mimicking the Frank-Starling mechanism of the heart. These flow adjustment strategies include modulation by CF-LVAD pump speed by synchrony and maintenance of constant flow or constant pressure head, or a combination of these variables. However, none of these adjustment strategies have evolved sufficiently to gain widespread attention. Herein we review the current challenges and future directions of CF-LVAD therapy and sensor technology focusing on the development of a physiologic, long-term active flow adjustment strategy for CF-LVADs.

  5. Neural signatures of adaptive post-error adjustments in visual search.

    PubMed

    Steinhauser, Robert; Maier, Martin E; Steinhauser, Marco

    2017-02-22

    Errors in speeded choice tasks can lead to post-error adjustments both on the behavioral and on the neural level. There is an ongoing debate whether such adjustments result from adaptive processes that serve to optimize performance or whether they reflect interference from error monitoring or attentional orientation. The present study aimed at identifying adaptive adjustments in a two-stage visual search task, in which participants had to select and subsequently identify a target stimulus presented to the left or right visual hemifield. Target selection and identification can be measured by two distinct event-related potentials, the N2pc and the SPCN. Using a decoder analysis based on multivariate pattern analysis, we were able to isolate the processing stages related to error sources and post-error adjustments. Whereas errors were linked to deviations in the N2pc and the SPCN, only for the N2pc we identified a post-error adjustment, which exhibits key features of source-specific adaptivity. While errors were associated with an increased N2pc, post-error adjustments consisted in an N2pc decrease. We interpret this as an adaptive adjustment of target selection to prevent errors due to disproportionate processing of the task-irrelevant target location. Our study thus provides evidence for adaptive post-error adjustments in visual search.

  6. SEAL FOR HIGH SPEED CENTRIFUGE

    DOEpatents

    Skarstrom, C.W.

    1957-12-17

    A seal is described for a high speed centrifuge wherein the centrifugal force of rotation acts on the gasket to form a tight seal. The cylindrical rotating bowl of the centrifuge contains a closure member resting on a shoulder in the bowl wall having a lower surface containing bands of gasket material, parallel and adjacent to the cylinder wall. As the centrifuge speed increases, centrifugal force acts on the bands of gasket material forcing them in to a sealing contact against the cylinder wall. This arrangememt forms a simple and effective seal for high speed centrifuges, replacing more costly methods such as welding a closure in place.

  7. Development of Air Speed Nozzles

    NASA Technical Reports Server (NTRS)

    Zahm, A F

    1920-01-01

    Report describes the development of a suitable speed nozzle for the first few thousand airplanes made by the United States during the recent war in Europe, and to furnish a basis for more mature instruments in the future. Requirements for the project were to provide a suitable pressure collector for aircraft speed meters and to develop a speed nozzle which would be waterproof, powerful, unaffected by slight pitch and yaw, rugged and easy to manufacture, and uniform in structure and reading, so as not to require individual calibration.

  8. High-Speed Schlieren Movies of Decelerators at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    1960-01-01

    Tests were conducted on several types of porous parachutes, a paraglider, and a simulated retrorocket. Mach numbers ranged from 1.8-3.0, porosity from 20-80 percent, and camera speeds from 1680-3000 feet per second (fps) in trials with porous parachutes. Trials of reefed parachutes were conducted at Mach number 2.0 and reefing of 12-33 percent at camera speeds of 600 fps. A flexible parachute with an inflatable ring in the periphery of the canopy was tested at Reynolds number 750,000 per foot, Mach number 2.85, porosity of 28 percent, and camera speed of 36oo fps. A vortex-ring parachute was tested at Mach number 2.2 and camera speed of 3000 fps. The paraglider, with a sweepback of 45 degrees at an angle of attack of 45 degrees was tested at Mach number 2.65, drag coefficient of 0.200, and lift coefficient of 0.278 at a camera speed of 600 fps. A cold air jet exhausting upstream from the center of a bluff body was used to simulate a retrorocket. The free-stream Mach number was 2.0, free-stream dynamic pressure was 620 lb/sq ft, jet-exit static pressure ratio was 10.9, and camera speed was 600 fps.

  9. Large aperture ac interferometer for optical testing.

    PubMed

    Moore, D T; Murray, R; Neves, F B

    1978-12-15

    A 20-cm clear aperture modified Twyman-Green interferometer is described. The system measures phase with an AC technique called phase-lock interferometry while scanning the aperture with a dual galvanometer scanning system. Position information and phase are stored in a minicomputer with disk storage. This information is manipulated with associated software, and the wavefront deformation due to a test component is graphically displayed in perspective and contour on a CRT terminal.

  10. YBCO Coated Conductors with Reduced AC Losses

    DTIC Science & Technology

    2008-01-30

    application such as turbo- generators and gyrotron magnets . The major reason is the enhanced in-field performance at 50-65 K and the proven...transformers, current limiters and the stators of rotating equipment. Low AC-loss in 2G HTS requires wire components with low magnetism , and an YBCO...layer with low transport and low hysteretic losses in an alternating magnetic field. The latter loss type requires a suitable filamentization technique

  11. AC plasma anemometer—characteristics and design

    NASA Astrophysics Data System (ADS)

    Marshall, Curtis; Matlis, Eric; Corke, Thomas; Gogineni, Sivaram

    2015-08-01

    The characteristics and design of a high-bandwidth flow sensor that uses an AC glow discharge (plasma) as the sensing element is presented. The plasma forms in the air gap between two protruding low profile electrodes attached to a probe body. The output from the anemometer is an amplitude modulated version of the AC voltage input that contains information about the mean and fluctuating velocity components. The anemometer circuitry includes resistance and capacitance elements that simulate a dielectric-barrier to maintain a diffuse plasma, and a constant-current feedback control that maintains operation within the desired glow discharge regime over an extended range of air velocities. Mean velocity calibrations are demonstrated over a range from 0 to 140 m s-1. Over this velocity range, the mean output voltage varied linearly with air velocity, providing a constant static sensitivity. The effect of the electrode gap and input AC carrier frequency on the anemometer static sensitivity and dynamic response are investigated. Experiments are performed to compare measurements obtained with a plasma sensor operating at two AC carrier frequencies against that of a constant-temperature hot-wire. All three sensors were calibrated against the same known velocity reference. An uncertainty based on the standard deviation of the velocity calibration fit was applied to the mean and fluctuating velocity measurements of the three sensors. The motivation is not to replace hot-wires as a general measurement tool, but rather as an alternative to hot-wires in harsh environments or at high Mach numbers where they either have difficulty in surviving or lack the necessary frequency response.

  12. THE ACS NEARBY GALAXY SURVEY TREASURY

    SciTech Connect

    Dalcanton, Julianne J.; Williams, Benjamin F.; Rosema, Keith; Gogarten, Stephanie M.; Christensen, Charlotte; Gilbert, Karoline; Hodge, Paul; Seth, Anil C.; Dolphin, Andrew; Holtzman, Jon; Skillman, Evan D.; Weisz, Daniel; Cole, Andrew; Girardi, Leo; Karachentsev, Igor D.; Olsen, Knut; Freeman, Ken; Gallart, Carme; De Jong, Roelof S. E-mail: ben@astro.washington.edu E-mail: stephanie@astro.washington.edu E-mail: fabio@astro.washington.edu E-mail: aseth@cfa.harvard.edu

    2009-07-15

    The ACS Nearby Galaxy Survey Treasury (ANGST) is a systematic survey to establish a legacy of uniform multi-color photometry of resolved stars for a volume-limited sample of nearby galaxies (D < 4 Mpc). The survey volume encompasses 69 galaxies in diverse environments, including close pairs, small and large groups, filaments, and truly isolated regions. The galaxies include a nearly complete range of morphological types spanning a factor of {approx}10{sup 4} in luminosity and star formation rate. The survey data consist of images taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST), supplemented with archival data and new Wide Field Planetary Camera 2 (WFPC2) imaging taken after the failure of ACS. Survey images include wide field tilings covering the full radial extent of each galaxy, and single deep pointings in uncrowded regions of the most massive galaxies in the volume. The new wide field imaging in ANGST reaches median 50% completenesses of m {sub F475W} = 28.0 mag, m {sub F606W} = 27.3 mag, and m {sub F814W} = 27.3 mag, several magnitudes below the tip of the red giant branch (TRGB). The deep fields reach magnitudes sufficient to fully resolve the structure in the red clump. The resulting photometric catalogs are publicly accessible and contain over 34 million photometric measurements of >14 million stars. In this paper we present the details of the sample selection, imaging, data reduction, and the resulting photometric catalogs, along with an analysis of the photometric uncertainties (systematic and random), for both ACS and WFPC2 imaging. We also present uniformly derived relative distances measured from the apparent magnitude of the TRGB.

  13. Graphs for Isotopes of 89-Ac (Actinium)

    NASA Astrophysics Data System (ADS)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides a graphic representation of nucleon separation energies and residual interaction parameters for isotopes of the chemical element 89-Ac (Actinium, atomic number Z = 89).

  14. The ACS Nearby Galaxy Survey Treasury

    NASA Astrophysics Data System (ADS)

    Dalcanton, Julianne J.; Williams, Benjamin F.; Seth, Anil C.; Dolphin, Andrew; Holtzman, Jon; Rosema, Keith; Skillman, Evan D.; Cole, Andrew; Girardi, Léo; Gogarten, Stephanie M.; Karachentsev, Igor D.; Olsen, Knut; Weisz, Daniel; Christensen, Charlotte; Freeman, Ken; Gilbert, Karoline; Gallart, Carme; Harris, Jason; Hodge, Paul; de Jong, Roelof S.; Karachentseva, Valentina; Mateo, Mario; Stetson, Peter B.; Tavarez, Maritza; Zaritsky, Dennis; Governato, Fabio; Quinn, Thomas

    2009-07-01

    The ACS Nearby Galaxy Survey Treasury (ANGST) is a systematic survey to establish a legacy of uniform multi-color photometry of resolved stars for a volume-limited sample of nearby galaxies (D < 4 Mpc). The survey volume encompasses 69 galaxies in diverse environments, including close pairs, small and large groups, filaments, and truly isolated regions. The galaxies include a nearly complete range of morphological types spanning a factor of ~104 in luminosity and star formation rate. The survey data consist of images taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST), supplemented with archival data and new Wide Field Planetary Camera 2 (WFPC2) imaging taken after the failure of ACS. Survey images include wide field tilings covering the full radial extent of each galaxy, and single deep pointings in uncrowded regions of the most massive galaxies in the volume. The new wide field imaging in ANGST reaches median 50% completenesses of m F475W = 28.0 mag, m F606W = 27.3 mag, and m F814W = 27.3 mag, several magnitudes below the tip of the red giant branch (TRGB). The deep fields reach magnitudes sufficient to fully resolve the structure in the red clump. The resulting photometric catalogs are publicly accessible and contain over 34 million photometric measurements of >14 million stars. In this paper we present the details of the sample selection, imaging, data reduction, and the resulting photometric catalogs, along with an analysis of the photometric uncertainties (systematic and random), for both ACS and WFPC2 imaging. We also present uniformly derived relative distances measured from the apparent magnitude of the TRGB.

  15. Demonstration of variable speed permanent magnet generator at small, low-head hydro site

    SciTech Connect

    Brown Kinloch, David

    2015-12-18

    Small hydro developers face a limited set of bad choices when choosing a generator for a small low-head hydro site. Direct drive synchronous generators are expensive and technically complex to install. Simpler induction generators are higher speed, requiring a speed increaser, which results in inefficiencies and maintenance problems. In addition, both induction and synchronous generators turn at a fixed speed, causing the turbine to run off its peak efficiency curve whenever the available head is different than the designed optimum head.The solution to these problems is the variable speed Permanent Magnet Generators (PMG). At the Weisenberger Mill in Midway, KY, a variable speed Permanent Magnet Generator has been installed and demonstrated. This new PMG system replaced an existing induction generator that had a HTD belt drive speed increaser system. Data was taken from the old generator before it was removed and compared to data collected after the PMG system was installed. The new variable speed PMG system is calculated to produce over 96% more energy than the old induction generator system during an average year. This significant increase was primarily due to the PMG generator operating at the correct speed at the maximum head, and the ability for the PMG generator to reduce its speed to lower optimum speeds as the stream flow increased and the net head decreased.This demonstration showed the importance of being able to adjust the speed of fixed blade turbines. All fixed blade turbines with varying net heads could achieve higher efficiencies if the speed can be matched to the optimum speed as the head changes. In addition, this demonstration showed that there are many potential efficiencies that could be realized with variable speed technology at hydro sites where mismatched turbine and generator speeds result in lower power output, even at maximum head. Funding for this project came from the US Dept. of Energy, through Award Number DE-EE0005429.

  16. Direct Torque Control of a Small Wind Turbine with a Sliding-Mode Speed Controller

    NASA Astrophysics Data System (ADS)

    Sri Lal Senanayaka, Jagath; Karimi, Hamid Reza; Robbersmyr, Kjell G.

    2016-09-01

    In this paper. the method of direct torque control in the presence of a sliding-mode speed controller is proposed for a small wind turbine being used in water heating applications. This concept and control system design can be expanded to grid connected or off-grid applications. Direct torque control of electrical machines has shown several advantages including very fast dynamics torque control over field-oriented control. Moreover. the torque and flux controllers in the direct torque control algorithms are based on hvsteretic controllers which are nonlinear. In the presence of a sliding-mode speed control. a nonlinear control system can be constructed which is matched for AC/DC conversion of the converter that gives fast responses with low overshoots. The main control objectives of the proposed small wind turbine can be maximum power point tracking and soft-stall power control. This small wind turbine consists of permanent magnet synchronous generator and external wind speed. and rotor speed measurements are not required for the system. However. a sensor is needed to detect the rated wind speed overpass events to activate proper speed references for the wind turbine. Based on the low-cost design requirement of small wind turbines. an available wind speed sensor can be modified. or a new sensor can be designed to get the required measurement. The simulation results will be provided to illustrate the excellent performance of the closed-loop control system in entire wind speed range (4-25 m/s).

  17. Level structure and reflection asymmetric shape in sup 223 Ac

    SciTech Connect

    Sheline, R.K.; Liang, C.F.; Paris, P. )

    1990-07-20

    Mass separated sources of {sup 227}Pa (separated as PaF{sub 4}{sup +} ions) were used to study the level structure of {sup 223}Ac following alpha decay. The levels in {sup 223}Ac are interpreted as K = 5/2{sup {plus minus}} parity doublet bands which occur naturally in reflection asymmetric models and the multiphonon octupole model. The anomalous structure of the K = 3/2{sup {minus}} band is explained in terms of Coriolis coupling. The low lying parity doublet bands in {sup 223}Ac, {sup 225}Ac, and {sup 227}Ac are compared and contrasted.

  18. Channel model for AC electric arc

    NASA Astrophysics Data System (ADS)

    Larsen, H. L.

    1993-06-01

    This report contains the results from calculations of free-burning AC electric arcs in argon. In order to calculate the arc current and arc voltage, the external electric circuit must be taken into consideration. The external circuit is modeled by an equivalent circuit consisting of an ideal AC voltage source, a loss resistance, and an inductance. The qualitative behavior of the current-voltage characteristic is in agreement with observed characteristics, but experimental data are necessary in order to check whether the calculated power loss is reasonable. Non-symmetry was modeled by introducing different anode and cathode falls in the two half periods. An attempt at taking into account different cathode current densities in the two half periods, depending on whether the electrode or silicon melt is cathode, did not give satisfactory results. Thermionic emission was assumed in both half periods, but this may not be the right mechanism when the silicon melt is cathode. The time delay of the AC arc compared to the DC case is modeled by a time constant. It was shown that this preset time constant must be in agreement with the mean 'mechanical' relaxation time in the arc in order to fulfill the energy balance. By updating the time constant until this is achieved, the time constant is eliminated as a parameter that must be chosen a priori.

  19. The ACS Nearby Galaxy Survey Treasury

    NASA Astrophysics Data System (ADS)

    Weisz, Daniel R.

    2010-01-01

    The ACS Nearby Galaxy Survey Treasury (ANGST) is a systematic survey to establish a legacy of uniform multi-color photometry of resolved stars for a volume-limited sample of nearby galaxies (D<4Mpc). The survey volume encompasses 69 galaxies in diverse environments, including close pairs, small & large groups, filaments, and truly isolated regions. The galaxies include a nearly complete range of morphological types spanning a factor of 104 in luminosity and star formation rate. The survey data consists of images taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope, supplemented with archival data and new Wide Field Planetary Camera (WFPC2) imaging taken after the failure of ACS. Survey images include wide field tilings covering the full radial extent of each galaxy, and single deep pointings in uncrowded regions of the most massive galaxies in the volume. We will discuss the many ways in which this data set is being used to reconstruct the star formation history of galaxies within the local volume.

  20. High-Speed Ring Bus

    NASA Technical Reports Server (NTRS)

    Wysocky, Terry; Kopf, Edward, Jr.; Katanyoutananti, Sunant; Steiner, Carl; Balian, Harry

    2010-01-01

    The high-speed ring bus at the Jet Propulsion Laboratory (JPL) allows for future growth trends in spacecraft seen with future scientific missions. This innovation constitutes an enhancement of the 1393 bus as documented in the Institute of Electrical and Electronics Engineers (IEEE) 1393-1999 standard for a spaceborne fiber-optic data bus. It allows for high-bandwidth and time synchronization of all nodes on the ring. The JPL ring bus allows for interconnection of active units with autonomous operation and increased fault handling at high bandwidths. It minimizes the flight software interface with an intelligent physical layer design that has few states to manage as well as simplified testability. The design will soon be documented in the AS-1393 standard (Serial Hi-Rel Ring Network for Aerospace Applications). The framework is designed for "Class A" spacecraft operation and provides redundant data paths. It is based on "fault containment regions" and "redundant functional regions (RFR)" and has a method for allocating cables that completely supports the redundancy in spacecraft design, allowing for a complete RFR to fail. This design reduces the mass of the bus by incorporating both the Control Unit and the Data Unit in the same hardware. The standard uses ATM (asynchronous transfer mode) packets, standardized by ITU-T, ANSI, ETSI, and the ATM Forum. The IEEE-1393 standard uses the UNI form of the packet and provides no protection for the data portion of the cell. The JPL design adds optional formatting to this data portion. This design extends fault protection beyond that of the interconnect. This includes adding protection to the data portion that is contained within the Bus Interface Units (BIUs) and by adding to the signal interface between the Data Host and the JPL 1393 Ring Bus. Data transfer on the ring bus does not involve a master or initiator. Following bus protocol, any BIU may transmit data on the ring whenever it has data received from its host. There

  1. Swimming speed of larval snail does not correlate with size and ciliary beat frequency.

    PubMed

    Chan, Kit Yu Karen; Jiang, Houshuo; Padilla, Dianna K

    2013-01-01

    Many marine invertebrates have planktonic larvae with cilia used for both propulsion and capturing of food particles. Hence, changes in ciliary activity have implications for larval nutrition and ability to navigate the water column, which in turn affect survival and dispersal. Using high-speed high-resolution microvideography, we examined the relationship between swimming speed, velar arrangements, and ciliary beat frequency of freely swimming veliger larvae of the gastropod Crepidula fornicata over the course of larval development. Average swimming speed was greatest 6 days post hatching, suggesting a reduction in swimming speed towards settlement. At a given age, veliger larvae have highly variable speeds (0.8-4 body lengths s(-1)) that are independent of shell size. Contrary to the hypothesis that an increase in ciliary beat frequency increases work done, and therefore speed, there was no significant correlation between swimming speed and ciliary beat frequency. Instead, there are significant correlations between swimming speed and visible area of the velar lobe, and distance between centroids of velum and larval shell. These observations suggest an alternative hypothesis that, instead of modifying ciliary beat frequency, larval C. fornicata modify swimming through adjustment of velum extension or orientation. The ability to adjust velum position could influence particle capture efficiency and fluid disturbance and help promote survival in the plankton.

  2. Dynamic Dazzle Distorts Speed Perception

    PubMed Central

    Hall, Joanna R.; Cuthill, Innes C.; Baddeley, Roland; Attwood, Angela S.; Munafò, Marcus R.; Scott-Samuel, Nicholas E.

    2016-01-01

    Static high contrast (‘dazzle’) patterns, such as zigzags, have been shown to reduce the perceived speed of an object. It has not escaped our notice that this effect has possible military applications and here we report a series of experiments on humans, designed to establish whether dynamic dazzle patterns can cause distortions of perceived speed sufficient to provide effective defence in the field, and the extent to which these effects are robust to a battery of manipulations. Dynamic stripe patterns moving in the same direction as the target are found to increase the perceived speed of that target, whilst dynamic stripes moving in the opposite direction to the target reduce the perceived speed. We establish the optimum position for such dazzle patches; confirm that reduced contrast and the addition of colour do not affect the performance of the dynamic dazzle, and finally, using the CO2 challenge, show that the effect is robust to stressful conditions. PMID:27196098

  3. Driving Speed vs Fuel Efficiency.

    ERIC Educational Resources Information Center

    Vest, Floyd

    1980-01-01

    A mathematical treatment of the relationship between driving speed and fuel efficiency is presented. The material involves applications of exponentials, logarithms, and elementary calculus, and is intended to be enrichment material for secondary and lower college mathematics classes. (MP)

  4. High-Speed Electrochemical Imaging.

    PubMed

    Momotenko, Dmitry; Byers, Joshua C; McKelvey, Kim; Kang, Minkyung; Unwin, Patrick R

    2015-09-22

    The design, development, and application of high-speed scanning electrochemical probe microscopy is reported. The approach allows the acquisition of a series of high-resolution images (typically 1000 pixels μm(-2)) at rates approaching 4 seconds per frame, while collecting up to 8000 image pixels per second, about 1000 times faster than typical imaging speeds used up to now. The focus is on scanning electrochemical cell microscopy (SECCM), but the principles and practicalities are applicable to many electrochemical imaging methods. The versatility of the high-speed scan concept is demonstrated at a variety of substrates, including imaging the electroactivity of a patterned self-assembled monolayer on gold, visualization of chemical reactions occurring at single wall carbon nanotubes, and probing nanoscale electrocatalysts for water splitting. These studies provide movies of spatial variations of electrochemical fluxes as a function of potential and a platform for the further development of high speed scanning with other electrochemical imaging techniques.

  5. High-speed Wind Tunnels

    NASA Technical Reports Server (NTRS)

    Ackeret, J

    1936-01-01

    Wind tunnel construction and design is discussed especially in relation to subsonic and supersonic speeds. Reynolds Numbers and the theory of compressible flows are also taken into consideration in designing new tunnels.

  6. Honeybees' Speed Depends on Dorsal as Well as Lateral, Ventral and Frontal Optic Flows

    PubMed Central

    Portelli, Geoffrey; Ruffier, Franck; Roubieu, Frédéric L.; Franceschini, Nicolas

    2011-01-01

    Flying insects use the optic flow to navigate safely in unfamiliar environments, especially by adjusting their speed and their clearance from surrounding objects. It has not yet been established, however, which specific parts of the optical flow field insects use to control their speed. With a view to answering this question, freely flying honeybees were trained to fly along a specially designed tunnel including two successive tapering parts: the first part was tapered in the vertical plane and the second one, in the horizontal plane. The honeybees were found to adjust their speed on the basis of the optic flow they perceived not only in the lateral and ventral parts of their visual field, but also in the dorsal part. More specifically, the honeybees' speed varied monotonically, depending on the minimum cross-section of the tunnel, regardless of whether the narrowing occurred in the horizontal or vertical plane. The honeybees' speed decreased or increased whenever the minimum cross-section decreased or increased. In other words, the larger sum of the two opposite optic flows in the horizontal and vertical planes was kept practically constant thanks to the speed control performed by the honeybees upon encountering a narrowing of the tunnel. The previously described ALIS (“AutopiLot using an Insect-based vision System”) model nicely matches the present behavioral findings. The ALIS model is based on a feedback control scheme that explains how honeybees may keep their speed proportional to the minimum local cross-section of a tunnel, based solely on optic flow processing, without any need for speedometers or rangefinders. The present behavioral findings suggest how flying insects may succeed in adjusting their speed in their complex foraging environments, while at the same time adjusting their distance not only from lateral and ventral objects but also from those located in their dorsal visual field. PMID:21589861

  7. Honeybees' speed depends on dorsal as well as lateral, ventral and frontal optic flows.

    PubMed

    Portelli, Geoffrey; Ruffier, Franck; Roubieu, Frédéric L; Franceschini, Nicolas

    2011-05-12

    Flying insects use the optic flow to navigate safely in unfamiliar environments, especially by adjusting their speed and their clearance from surrounding objects. It has not yet been established, however, which specific parts of the optical flow field insects use to control their speed. With a view to answering this question, freely flying honeybees were trained to fly along a specially designed tunnel including two successive tapering parts: the first part was tapered in the vertical plane and the second one, in the horizontal plane. The honeybees were found to adjust their speed on the basis of the optic flow they perceived not only in the lateral and ventral parts of their visual field, but also in the dorsal part. More specifically, the honeybees' speed varied monotonically, depending on the minimum cross-section of the tunnel, regardless of whether the narrowing occurred in the horizontal or vertical plane. The honeybees' speed decreased or increased whenever the minimum cross-section decreased or increased. In other words, the larger sum of the two opposite optic flows in the horizontal and vertical planes was kept practically constant thanks to the speed control performed by the honeybees upon encountering a narrowing of the tunnel. The previously described ALIS ("AutopiLot using an Insect-based vision System") model nicely matches the present behavioral findings. The ALIS model is based on a feedback control scheme that explains how honeybees may keep their speed proportional to the minimum local cross-section of a tunnel, based solely on optic flow processing, without any need for speedometers or rangefinders. The present behavioral findings suggest how flying insects may succeed in adjusting their speed in their complex foraging environments, while at the same time adjusting their distance not only from lateral and ventral objects but also from those located in their dorsal visual field.

  8. Sound speed criterion for two-phase critical flow

    NASA Astrophysics Data System (ADS)

    Chung, M.-S.; Park, S.-B.; Lee, H.-K.

    2004-09-01

    Critical flow simulation for non-homogeneous, non-equilibrium two-phase flows is improved by applying a new sound speed model which is derived from the characteristic analysis of hyperbolic two-fluid model. The hyperbolicity of two-fluid model was based on the concept of surface tension for the interfacial pressure jump terms in the momentum equations. Real eigenvalues obtained as the closed-form solution of characteristic polynomial represent the sound speeds in the bubbly flow regime that agree well with the existing experimental data. The analytic sound speed is consistent with that obtained by the earlier study of Nguyen et al. though there is a difference between them especially in the limiting condition. The present sound speed shows more reasonable result in that condition than Nguyen et al.'s does. The present critical flow criterion derived by the present sound speed is employed in the MARS code and is assessed by treating several nozzle flow tests. The assessment results, without any adjustment made by some discharge coefficients, demonstrate more accurate predictions of critical flow rate than those of the earlier critical flow calculations in the bubbly flow regime.

  9. Total AC losses in twisted and untwisted multifilamentary Bi-2223 superconducting tapes carrying AC transport current in AC longitudinal magnetic field

    NASA Astrophysics Data System (ADS)

    Amemiya, Naoyuki; Jin, Feng; Jiang, Zhenan; Shirai, Shunsuke; ten Haken, Bennie; Rabbers, Jan-Jaap; Ayai, Naoki; Hayashi, Kazuhiko

    2003-03-01

    In some electrical apparatuses, superconducting tapes are exposed to the longitudinal magnetic field. In this work, AC losses were measured in twisted and untwisted Bi-2223 tapes carrying AC transport current in the AC longitudinal magnetic field. In twisted tapes, the transport, magnetization and total losses depend on the relative direction of the longitudinal magnetic field to the direction of the transport current, while the field direction does not influence the AC loss characteristics in untwisted tapes. In the Z-twisted tapes, the total AC loss is larger in the longitudinal magnetic field that is anti-parallel to the transport current than in the longitudinal magnetic field of another direction. Numerical analysis shows that this field direction dependence of the total AC loss results from the change in the current distribution. In the longitudinal magnetic field that is anti-parallel to the transport current, the total AC loss in the Z-twisted tape is more than that in the untwisted tape. This dependence on the field direction is reversed in S-twisted tapes. It is to be noted that the twist increases the total AC loss in a longitudinal magnetic field of a certain direction, while it reduces the AC loss in the transverse magnetic field.

  10. Gated high speed optical detector

    NASA Technical Reports Server (NTRS)

    Green, S. I.; Carson, L. M.; Neal, G. W.

    1973-01-01

    The design, fabrication, and test of two gated, high speed optical detectors for use in high speed digital laser communication links are discussed. The optical detectors used a dynamic crossed field photomultiplier and electronics including dc bias and RF drive circuits, automatic remote synchronization circuits, automatic gain control circuits, and threshold detection circuits. The equipment is used to detect binary encoded signals from a mode locked neodynium laser.

  11. Applications of High Speed Networks

    DTIC Science & Technology

    1991-09-01

    extended computer interconnections are the charactenstic properties of ligh speed networks, low error rates, high bandwidth, low latency, full...implementation and designi of ligh speed networks, the need for gigabit per second services for an end user will be justified. A. FIBER OPTICS 1. Brief...conferencing muc& more useful. 5. Full motion video - HDTV The distribution of entertainment and news, based on broadcast signals, has been an activity

  12. Code Speed Measuring for VC++

    DTIC Science & Technology

    2015-10-01

    UNCLASSIFIED AD-E403 688 Technical Report ARWSE-TR-14025 CODE SPEED MEASURING FOR VC++ Tom Nealis...TYPE Final 3. DATES COVERED (From – To) 4. TITLE AND SUBTITLE CODE SPEED MEASURING FOR VC++ 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...ABSTRACT It’s often important to know how fast a snippet of code executes. This information allows the coder to make important decisions

  13. Do speed cameras reduce collisions?

    PubMed

    Skubic, Jeffrey; Johnson, Steven B; Salvino, Chris; Vanhoy, Steven; Hu, Chengcheng

    2013-01-01

    We investigated the effects of speed cameras along a 26 mile segment in metropolitan Phoenix, Arizona. Motor vehicle collisions were retrospectively identified according to three time periods - before cameras were placed, while cameras were in place and after cameras were removed. A 14 mile segment in the same area without cameras was used for control purposes. Five cofounding variables were eliminated. In this study, the placement or removal of interstate highway speed cameras did not independently affect the incidence of motor vehicle collisions.

  14. Sustained Swimming Speeds of Dolphins.

    PubMed

    Johannessen, C L; Harder, J A

    1960-11-25

    Observations of fout large groups of dolphins suggest that they are able to swim at a sustained speed of 14 to 18 knots. The blackfish are able to maintain speeds of about 22 knots, and one killer whale seemed able to swim somewhat faster. This implies that the apparent coefficient of surface friction remains approximately constant for dolphins from 6 to 22 ft long, as is the case for rigid bodies.

  15. 49 CFR 230.68 - Speed indicators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Speed indicators. 230.68 Section 230.68... Tenders Speed Indicators § 230.68 Speed indicators. Steam locomotives that operate at speeds in excess of... indicators. Where equipped, speed indicators shall be maintained to ensure accurate functioning. Ash Pans...

  16. 36 CFR 4.21 - Speed limits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Speed limits. 4.21 Section 4... TRAFFIC SAFETY § 4.21 Speed limits. (a) Park area speed limits are as follows: (1) 15 miles per hour... superintendent may designate a different speed limit upon any park road when a speed limit set forth in...

  17. Speed Variance and Its Influence on Accidents.

    ERIC Educational Resources Information Center

    Garber, Nicholas J.; Gadirau, Ravi

    A study was conducted to investigate the traffic engineering factors that influence speed variance and to determine to what extent speed variance affects accident rates. Detailed analyses were carried out to relate speed variance with posted speed limit, design speeds, and other traffic variables. The major factor identified was the difference…

  18. 49 CFR 230.68 - Speed indicators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Speed indicators. 230.68 Section 230.68... Tenders Speed Indicators § 230.68 Speed indicators. Steam locomotives that operate at speeds in excess of... indicators. Where equipped, speed indicators shall be maintained to ensure accurate functioning. Ash Pans...

  19. AC loss measurements of twisted and untwisted BSCCO multifilamentary tapes

    NASA Astrophysics Data System (ADS)

    Jiang, Zhenan; Amemiya, Naoyuki; Nishioka, Takamasa; Oh, Sang-Soo

    2005-01-01

    AC losses in twisted and untwisted BSCCO multifilamentary superconducting tapes with Ag matrix developed in DAPAS program were measured by an electrical method. Magnetization and transport losses were measured by a pick-up coil and by a voltage taps. Total AC loss during simultaneous application of AC transport current and an AC transverse magnetic field was given by the sum of the magnetization and transport losses measured during this simultaneous application. The magnetization loss without transport current of untwisted and twisted tapes was measured first to evaluate the effect of twisting to decouple filaments. Then, the total AC loss of the twisted tape was measured in transverse magnetic fields with various amplitudes and orientations, while the amplitude of the transport current was fixed. The measured total AC loss in a parallel transverse magnetic field was compared with some theoretical models to study the detailed characteristics of the measured total AC loss of the sample.

  20. A Variable Speed Fan Dynamometer

    NASA Technical Reports Server (NTRS)

    Wood, Karl D

    1920-01-01

    Fan brakes used as absorption dynamometers in testing internal combustion engines have the disadvantage that a given fan will run only at one speed when the engine is delivering full power. In order to be able to vary the speed at which a given power will be absorbed, English manufacturers have for some time been using a cylindrical housing around the fan with one or two variable openings in the periphery. Here, results are given of tests conducted to determine how great a range of speed can be obtained from such a device. The tests show that a power ratio of five to 1 can be obtained, the power ratio being defined as the ratio of the power absorbed by the fan at a given speed with the outlet open to the power absorbed at the same speed with the second outlet closed. Data show that improvements in the design of the fan brake can make the speed ratio approach but not exceed a value of two to one. Also given here are a brief outline of previous work on fan brakes, a description of the experimental apparatus and methods used in the tests, and a more detailed statement of test results.

  1. The Hubble Legacy Archive ACS grism data

    NASA Astrophysics Data System (ADS)

    Kümmel, M.; Rosati, P.; Fosbury, R.; Haase, J.; Hook, R. N.; Kuntschner, H.; Lombardi, M.; Micol, A.; Nilsson, K. K.; Stoehr, F.; Walsh, J. R.

    2011-06-01

    A public release of slitless spectra, obtained with ACS/WFC and the G800L grism, is presented. Spectra were automatically extracted in a uniform way from 153 archival fields (or "associations") distributed across the two Galactic caps, covering all observations to 2008. The ACS G800L grism provides a wavelength range of 0.55-1.00 μm, with a dispersion of 40 Å/pixel and a resolution of ~80 Å for point-like sources. The ACS G800L images and matched direct images were reduced with an automatic pipeline that handles all steps from archive retrieval, alignment and astrometric calibration, direct image combination, catalogue generation, spectral extraction and collection of metadata. The large number of extracted spectra (73,581) demanded automatic methods for quality control and an automated classification algorithm was trained on the visual inspection of several thousand spectra. The final sample of quality controlled spectra includes 47 919 datasets (65% of the total number of extracted spectra) for 32 149 unique objects, with a median iAB-band magnitude of 23.7, reaching 26.5 AB for the faintest objects. Each released dataset contains science-ready 1D and 2D spectra, as well as multi-band image cutouts of corresponding sources and a useful preview page summarising the direct and slitless data, astrometric and photometric parameters. This release is part of the continuing effort to enhance the content of the Hubble Legacy Archive (HLA) with highly processed data products which significantly facilitate the scientific exploitation of the Hubble data. In order to characterize the slitless spectra, emission-line flux and equivalent width sensitivity of the ACS data were compared with public ground-based spectra in the GOODS-South field. An example list of emission line galaxies with two or more identified lines is also included, covering the redshift range 0.2 - 4.6. Almost all redshift determinations outside of the GOODS fields are new. The scope of science projects

  2. Ergonomic evaluation of the Apple Adjustable Keyboard

    SciTech Connect

    Tittiranonda, P.; Burastero, S.; Shih, M.; Rempel, D.

    1994-05-01

    This study presents an evaluation of the Apple Adjustable Keyboard based on subjective preference and observed joint angles during typing. Thirty five keyboard users were asked to use the Apple adjustable keyboard for 7--14 days and rate the various characteristics of the keyboard. Our findings suggest that the most preferred opening angles range from 11--20{degree}. The mean ulnar deviation on the Apple Adjustable keyboard is 11{degree}, compared to 16{degree} on the standard keyboard. The mean extension was decreased from 24{degree} to 16{degree} when using the adjustable keyboard. When asked to subjectively rate the adjustable keyboard in comparison to the standard, the average subject felt that the Apple Adjustable Keyboard was more comfortable and easier to use than the standard flat keyboard.

  3. Efficient Adjustable Reflectivity Smart Window

    SciTech Connect

    D. Morgan Tench

    2005-12-01

    This project addressed the key technical issues for development of an efficient smart window based on reversible electrochemical transfer of silver between a mirror electrode and a localized counter electrode. Effort to provide uniform switching over large areas focused on use of a resistive transparent electrode innerlayer to increase the interelectrode resistance. An effective edge seal was developed in collaboration with adhesive suppliers and an electrochromic device manufacturer. Work to provide a manufacturable counter electrode focused on fabricating a dot matrix electrode without photolithography by electrodeposition of Pt nuclei on inherent active sites on a transparent oxide conductor. An alternative counter electrode based on a conducting polymer and an ionic liquid electrolyte was also investigated. Work in all of these areas was successful. Sputtered large-bandgap oxide innerlayers sandwiched between conductive indium tin oxide (ITO) layers were shown to provide sufficient cross-layer resistance (>300 ohm/cm{sup 2}) without significantly affecting the electrochemical properties of the ITO overlayer. Two edge seal epoxies, one procured from an epoxy manufacturer and one provided by an electrochromic device manufacturer in finished seals, were shown to be effective barriers against oxygen intrusion up to 80 C. The optimum density of nuclei for the dot matrix counter electrode was attained without use of photolithography by electrodeposition from a commercial alkaline platinum plating bath. Silver loss issues for cells with dot matrix electrodes were successfully addressed by purifying the electrolyte and adjusting the cell cycling parameters. More than 30K cycles were demonstrated for a REM cell (30-cm square) with a dot matrix counter electrode. Larger cells (30-cm square) were successfully fabricated but could not be cycled since the nucleation layers (provided by an outside supplier) were defective so that mirror deposits could not be produced.

  4. Speed-accuracy tradeoff by a control signal with balanced excitation and inhibition

    PubMed Central

    Lo, Chung-Chuan; Wang, Cheng-Te

    2015-01-01

    A hallmark of flexible behavior is the brain's ability to dynamically adjust speed and accuracy in decision-making. Recent studies suggested that such adjustments modulate not only the decision threshold, but also the rate of evidence accumulation. However, the underlying neuronal-level mechanism of the rate change remains unclear. In this work, using a spiking neural network model of perceptual decision, we demonstrate that speed and accuracy of a decision process can be effectively adjusted by manipulating a top-down control signal with balanced excitation and inhibition [balanced synaptic input (BSI)]. Our model predicts that emphasizing accuracy over speed leads to reduced rate of ramping activity and reduced baseline activity of decision neurons, which have been observed recently at the level of single neurons recorded from behaving monkeys in speed-accuracy tradeoff tasks. Moreover, we found that an increased inhibitory component of BSI skews the decision time distribution and produces a pronounced exponential tail, which is commonly observed in human studies. Our findings suggest that BSI can serve as a top-down control mechanism to rapidly and parametrically trade between speed and accuracy, and such a cognitive control signal presents both when the subjects emphasize accuracy or speed in perceptual decisions. PMID:25995354

  5. Three-dimensional adjustment of trilateration data

    NASA Technical Reports Server (NTRS)

    Sung, L.-Y.; Jackson, D. D.

    1985-01-01

    The three-dimensional locations of the monuments in the USGS Hollister trilateration network were adjusted to fit line length observations observed in 1977, using a Bayesian approach, and incorporating prior elevation estimates as data in the adjustment procedure. No significant discrepancies in the measured line lengths were found, but significant elevation adjustments (up to 1.85 m) were needed to fit the length data.

  6. Development of a uninterrupted power system: ac and dc to dc converter

    NASA Technical Reports Server (NTRS)

    Cronin, D. L.; Schoenfeld, A. D.

    1973-01-01

    This program covered the design, fabrication and testing of an advanced development model uninterrupted power system. The input and output requirements imposed on the power processor were specified such that the unit is electrically interchangeable with existing power systems used by the Federal Aviation Administration in installations which have a history of failure due to electrical transient conditions. Input power is from either of two single-phase ac power sources or batteries with electronic selection and transfer between power sources. Battery reconditioning is automatic when either ac source is present. The output power is rated at 84OW; the nominal output is 24V at 35A. Within the 84OW limit, the regulated output voltage is adjustable from 22V to 30Vdc. Protection against continuous overloading or short circuit is provided. The unit is packaged in a standard 19-inch rack mount configuration with 7-inch panel height. Controls are on the front panel with power input and output through connectors on the rear surface. Cooling is by free convection from fin areas located on the side and rear panels. The packaged unit weighs 52.8 lbs., which can be reduced significantly if a three-phase ac power source is used.

  7. Multi-adjustable headband. [for headsets

    NASA Technical Reports Server (NTRS)

    Toole, Pierce C. (Inventor); Chalson, Howard E. (Inventor); Bussey, Walter S. (Inventor)

    1988-01-01

    This invention relates to a headband for a headset having separate coarse and fine adjustment features. The adjustments may be to the axial distance between at least one earpiece element and a side support. Such adjustment to the axial distance varies the pressure exerted on the head of the user. The present fine adjustment feature may be used while the headset is being worn, thereby permitting a user to optimize the amount of pressure between the contending criteria of comfort and keeping the headset in place on the user's head.

  8. Standardization of age-adjusted mortality rates

    SciTech Connect

    Selvin, S.; Sacks, S.T.; Merrill, D.W.

    1980-02-01

    Because age is a significant variable in the occurrence and frequency of human disease, any comparison of disease or mortality rates, to be useful, must be age-specific or age-adjusted. Age-specific comparisons are not always appropriate or possible, however. A common method of eliminating the influence of age in comparing mortality rates from one community to another is to employ statistical methods of age-adjustment. While a variety of methods will accomplish this task, most are weighted averages of the age-specific rates. Two widely used adjustment procedures are direct and indirect age-adjustment.

  9. Deletion of the AcMNPV core gene ac109 results in budded virions that are non-infectious

    SciTech Connect

    Fang Minggang; Nie, Yingchao; Theilmann, David A.

    2009-06-20

    Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac109 is a core gene and its function in the virus life cycle is unknown. To determine its role in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an ac109 deletion virus (vAc{sup 109KO}). Fluorescence and light microscopy showed that transfection of vAc{sup 109KO} results in a single-cell infection phenotype. Viral DNA replication is unaffected and the development of occlusion bodies in vAc{sup 109KO}-transfected cells evidenced progression to the very late phases of viral infection. Western blot and confocal immunofluorescence analysis showed that AC109 is expressed in the cytoplasm and nucleus throughout infection. In addition, AC109 is a structural protein as it was detected in both budded virus (BV) and occlusion derived virus in both the envelope and nucleocapsid fractions. Titration assays by qPCR and TCID{sub 50} showed that vAc{sup 109KO} produced BV but the virions are non-infectious. The vAc{sup 109KO} BV were indistinguishable from the BV of repaired and wild type control viruses as determined by negative staining and electron microscopy.

  10. High-resolution ac-pulse modulated electrohydrodynamic jet printing on highly insulating substrates

    NASA Astrophysics Data System (ADS)

    Wei, Chuang; Qin, Hantang; Ramírez-Iglesias, Nakaira A.; Chiu, Chia-Pin; Lee, Yuan-shin; Dong, Jingyan

    2014-04-01

    This paper presents a new high-resolution ac-pulse modulated electrohydrodynamic (EHD)-jet printing technology on highly insulating substrates for drop-on-demand fabrication of electrical features and interconnects using silver nanoink. In traditional EHD-jet printing, the remained charge of the printed droplets changes the electrostatic field distribution and interrupts the follow-on printing behavior, especially for highly insulating substrates which have slow charge decay rates. The residue charge makes the control of EHD-jet printing very challenging for high-resolution continuous features. In this paper, by using modulated ac-pulsed voltage, the EHD-jet printing process switches the charge polarity of the consequent droplets to neutralize the charge on the substrate. The effect of the residue charge is minimized, which enables high-resolution printing of continuous patterns. Moreover, by modulating the pulse frequency, voltage, and duration, the EHD-jet printing behavior can be controlled with respect to printing speed/frequency and droplet size. Printing frequency is directly controlled by the pulse frequency, and the droplet dimension is controlled by the voltage and the duration of the pulse. We demonstrated that ac-pulse modulated EHD-jet printing can overcome the long-predicated charge accumulation problem on highly insulating substrates, and potentially be applied to many flexible electronics applications.

  11. Effect of speed matching on fundamental diagram of pedestrian flow

    NASA Astrophysics Data System (ADS)

    Fu, Zhijian; Luo, Lin; Yang, Yue; Zhuang, Yifan; Zhang, Peitong; Yang, Lizhong; Yang, Hongtai; Ma, Jian; Zhu, Kongjin; Li, Yanlai

    2016-09-01

    Properties of pedestrian may change along their moving path, for example, as a result of fatigue or injury, which has never been properly investigated in the past research. The paper attempts to study the speed matching effect (a pedestrian adjusts his velocity constantly to the average velocity of his neighbors) and its influence on the density-velocity relationship (a pedestrian adjust his velocity to the surrounding density), known as the fundamental diagram of the pedestrian flow. By the means of the cellular automaton, the simulation results fit well with the empirical data, indicating the great advance of the discrete model for pedestrian dynamics. The results suggest that the system velocity and flow rate increase obviously under a big noise, i.e., a diverse composition of pedestrian crowd, especially in the region of middle or high density. Because of the temporary effect, the speed matching has little influence on the fundamental diagram. Along the entire density, the relationship between the step length and the average pedestrian velocity is a piecewise function combined two linear functions. The number of conflicts reaches the maximum with the pedestrian density of 2.5 m-2, while decreases by 5.1% with the speed matching.

  12. 49 CFR 230.68 - Speed indicators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Speed Indicators § 230.68 Speed indicators. Steam locomotives that operate at speeds in excess...

  13. 49 CFR 230.68 - Speed indicators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Speed Indicators § 230.68 Speed indicators. Steam locomotives that operate at speeds in excess...

  14. 49 CFR 230.68 - Speed indicators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Speed Indicators § 230.68 Speed indicators. Steam locomotives that operate at speeds in excess...

  15. Combining Speed Information Across Space

    NASA Technical Reports Server (NTRS)

    Verghese, Preeti; Stone, Leland S.

    1995-01-01

    We used speed discrimination tasks to measure the ability of observers to combine speed information from multiple stimuli distributed across space. We compared speed discrimination thresholds in a classical discrimination paradigm to those in an uncertainty/search paradigm. Thresholds were measured using a temporal two-interval forced-choice design. In the discrimination paradigm, the n gratings in each interval all moved at the same speed and observers were asked to choose the interval with the faster gratings. Discrimination thresholds for this paradigm decreased as the number of gratings increased. This decrease was not due to increasing the effective stimulus area as a control experiment that increased the area of a single grating did not show a similar improvement in thresholds. Adding independent speed noise to each of the n gratings caused thresholds to decrease at a rate similar to the original no-noise case, consistent with observers combining an independent sample of speed from each grating in both the added- and no-noise cases. In the search paradigm, observers were asked to choose the interval in which one of the n gratings moved faster. Thresholds in this case increased with the number of gratings, behavior traditionally attributed to an input bottleneck. However, results from the discrimination paradigm showed that the increase was not due to observers' inability to process these gratings. We have also shown that the opposite trends of the data in the two paradigms can be predicted by a decision theory model that combines independent samples of speed information across space. This demonstrates that models typically used in classical detection and discrimination paradigms are also applicable to search paradigms. As our model does not distinguish between samples in space and time, it predicts that discrimination performance should be the same regardless of whether the gratings are presented in two spatial intervals or two temporal intervals. Our last

  16. Precision Adjustable Liquid Regulator (ALR)

    NASA Astrophysics Data System (ADS)

    Meinhold, R.; Parker, M.

    2004-10-01

    A passive mechanical regulator has been developed for the control of fuel or oxidizer flow to a 450N class bipropellant engine for use on commercial and interplanetary spacecraft. There are several potential benefits to the propulsion system, depending on mission requirements and spacecraft design. This system design enables more precise control of main engine mixture ratio and inlet pressure, and simplifies the pressurization system by transferring the function of main engine flow rate control from the pressurization/propellant tank assemblies, to a single component, the ALR. This design can also reduce the thermal control requirements on the propellant tanks, avoid costly Qualification testing of biprop engines for missions with more stringent requirements, and reduce the overall propulsion system mass and power usage. In order to realize these benefits, the ALR must meet stringent design requirements. The main advantage of this regulator over other units available in the market is that it can regulate about its nominal set point to within +/-0.85%, and change its regulation set point in flight +/-4% about that nominal point. The set point change is handled actively via a stepper motor driven actuator, which converts rotary into linear motion to affect the spring preload acting on the regulator. Once adjusted to a particular set point, the actuator remains in its final position unpowered, and the regulator passively maintains outlet pressure. The very precise outlet regulation pressure is possible due to new technology developed by Moog, Inc. which reduces typical regulator mechanical hysteresis to near zero. The ALR requirements specified an outlet pressure set point range from 225 to 255 psi, and equivalent water flow rates required were in the 0.17 lb/sec range. The regulation output pressure is maintained at +/-2 psi about the set point from a P (delta or differential pressure) of 20 to over 100 psid. Maximum upstream system pressure was specified at 320 psi

  17. Low speed phaselock speed control system. [for brushless dc motor

    NASA Technical Reports Server (NTRS)

    Fulcher, R. W.; Sudey, J. (Inventor)

    1975-01-01

    A motor speed control system for an electronically commutated brushless dc motor is provided which includes a phaselock loop with bidirectional torque control for locking the frequency output of a high density encoder, responsive to actual speed conditions, to a reference frequency signal, corresponding to the desired speed. The system includes a phase comparator, which produces an output in accordance with the difference in phase between the reference and encoder frequency signals, and an integrator-digital-to-analog converter unit, which converts the comparator output into an analog error signal voltage. Compensation circuitry, including a biasing means, is provided to convert the analog error signal voltage to a bidirectional error signal voltage which is utilized by an absolute value amplifier, rotational decoder, power amplifier-commutators, and an arrangement of commutation circuitry.

  18. Performance of a turbojet engine with adjustable first-stage turbine stator and variable-area exhaust nozzle

    NASA Technical Reports Server (NTRS)

    Meyer, Carl L; Smith, Ivan D; Bloomer, Harry E

    1953-01-01

    The performance of a turbojet engine with a two-stage turbine, an adjustable first-stage turbine stator, and a variable-area exhaust nozzle was investigated at selected constant engine speeds and two simulated flight conditions. For the particular component characteristics of the engine investigated, little improvement in thrust levels of interest by use of an adjustable rather than an optimum fixed first-stage turbine stator.

  19. Dazzle Camouflage Affects Speed Perception

    PubMed Central

    Scott-Samuel, Nicholas E.; Baddeley, Roland; Palmer, Chloe E.; Cuthill, Innes C.

    2011-01-01

    Movement is the enemy of camouflage: most attempts at concealment are disrupted by motion of the target. Faced with this problem, navies in both World Wars in the twentieth century painted their warships with high contrast geometric patterns: so-called “dazzle camouflage”. Rather than attempting to hide individual units, it was claimed that this patterning would disrupt the perception of their range, heading, size, shape and speed, and hence reduce losses from, in particular, torpedo attacks by submarines. Similar arguments had been advanced earlier for biological camouflage. Whilst there are good reasons to believe that most of these perceptual distortions may have occurred, there is no evidence for the last claim: changing perceived speed. Here we show that dazzle patterns can distort speed perception, and that this effect is greatest at high speeds. The effect should obtain in predators launching ballistic attacks against rapidly moving prey, or modern, low-tech battlefields where handheld weapons are fired from short ranges against moving vehicles. In the latter case, we demonstrate that in a typical situation involving an RPG7 attack on a Land Rover the reduction in perceived speed is sufficient to make the grenade miss where it was aimed by about a metre, which could be the difference between survival or not for the occupants of the vehicle. PMID:21673797

  20. Generalized Geometric Quantum Speed Limits

    NASA Astrophysics Data System (ADS)

    Pires, Diego Paiva; Cianciaruso, Marco; Céleri, Lucas C.; Adesso, Gerardo; Soares-Pinto, Diogo O.

    2016-04-01

    The attempt to gain a theoretical understanding of the concept of time in quantum mechanics has triggered significant progress towards the search for faster and more efficient quantum technologies. One of such advances consists in the interpretation of the time-energy uncertainty relations as lower bounds for the minimal evolution time between two distinguishable states of a quantum system, also known as quantum speed limits. We investigate how the nonuniqueness of a bona fide measure of distinguishability defined on the quantum-state space affects the quantum speed limits and can be exploited in order to derive improved bounds. Specifically, we establish an infinite family of quantum speed limits valid for unitary and nonunitary evolutions, based on an elegant information geometric formalism. Our work unifies and generalizes existing results on quantum speed limits and provides instances of novel bounds that are tighter than any established one based on the conventional quantum Fisher information. We illustrate our findings with relevant examples, demonstrating the importance of choosing different information metrics for open system dynamics, as well as clarifying the roles of classical populations versus quantum coherences, in the determination and saturation of the speed limits. Our results can find applications in the optimization and control of quantum technologies such as quantum computation and metrology, and might provide new insights in fundamental investigations of quantum thermodynamics.

  1. Family Adjustment Measure: Scale Construction and Validation

    ERIC Educational Resources Information Center

    Daire, Andrew P.; Dominguez, Vanessa N.; Carlson, Ryan G.; Case-Pease, Jenene

    2014-01-01

    We administered the Family Adjustment Measure to 368 parents of children with special needs to identify positive adjustment. We randomly split the sample to conduct exploratory factor analysis ("n" = 194) and confirmatory factor analysis ("n" = 174). Results indicated four possible subscales and that explain 51% of the variance.

  2. 49 CFR 630.11 - Data adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Data adjustments. 630.11 Section 630.11 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.11 Data adjustments. Errors in the data used...

  3. 49 CFR 630.11 - Data adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Data adjustments. 630.11 Section 630.11 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.11 Data adjustments. Errors in the data used...

  4. 49 CFR 630.11 - Data adjustments.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Data adjustments. 630.11 Section 630.11 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.11 Data adjustments. Errors in the data used...

  5. 49 CFR 630.11 - Data adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Data adjustments. 630.11 Section 630.11 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.11 Data adjustments. Errors in the data used...

  6. 49 CFR 630.11 - Data adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Data adjustments. 630.11 Section 630.11 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.11 Data adjustments. Errors in the data used...

  7. Parenting Styles and Adjustment in Gifted Children

    ERIC Educational Resources Information Center

    Pilarinos, Vassiliki; Solomon, C. R.

    2017-01-01

    The present study examined the relationship between parenting styles and the psychosocial adjustment of 48 children aged 7 to 11 years, each of whom had been identified as gifted on the basis of a score of 130 or above on the Wechsler Intelligence Scale for Children--Fourth Edition. Parenting styles and child psychosocial adjustment were measured…

  8. Ergonomically Adjustable School Furniture for Male Students

    ERIC Educational Resources Information Center

    Al-Saleh, Khalid S.; Ramadan, Mohamed Z.; Al-Ashaikh, Riyad A.

    2013-01-01

    The need for adjustability in school furniture, in order to accommodate the variation in anthropometric measures of different genders, cultures and ages is becoming increasingly important. Four chair-table combinations, different in dimensions, with adjustable chair seating heights and table heights were designed, manufactured and distributed to…

  9. Adjustable, Audible Continuity Tester For Delicate Circuits

    NASA Technical Reports Server (NTRS)

    Mcalister, William B.

    1988-01-01

    Unit adjustable to resistances up to 35 ohms. Adjustable, audible electrical-continuity tester gives audible indication. Used safely on circuit boards in which semiconductor components installed, and on complementary metal oxide/semiconductor integrated circuits. Tester compact and circuit simple. Built from inexpensive standard components.

  10. Adjustably Preloaded Quick-Release Pin

    NASA Technical Reports Server (NTRS)

    Reimers, Harold W.

    1992-01-01

    Modified adjustable-grip-length quick-release pin holds two bodies together. Threaded shaft of pin threaded in floating nut to pretension fastener. Pin connects and disconnects rapidly and adjusted to accommodate small differences between thicknesses of nominally identical sets of parts to be attached to each other.

  11. 78 FR 70080 - Market Dominant Price Adjustment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-22

    ... Market Dominant Price Adjustment AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: The... market dominant products. The adjustments are scheduled to take effect January 26, 2014. This notice.... Ordering Paragraphs I. Overview A. Index-Based Price Changes for Market Dominant Classes of Mail...

  12. College Student Adjustment and Health Behaviors

    ERIC Educational Resources Information Center

    Hall, Lisa Anne

    2010-01-01

    This study explored the relationship between student adjustment theory and college student health behaviors. Specifically, this research examined first-year freshmen college student physical activity and nutrition behaviors and impact on adjustment to college (N = 37,564). The design for this study was a non-experimental "ex post facto"…

  13. 34 CFR 36.2 - Penalty adjustment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Title IV of the HEA, which authorizes the Federal Family Education Loan Program $35,000. 20 U.S.C. 1094... 34 Education 1 2014-07-01 2014-07-01 false Penalty adjustment. 36.2 Section 36.2 Education Office of the Secretary, Department of Education ADJUSTMENT OF CIVIL MONETARY PENALTIES FOR INFLATION §...

  14. 28 CFR 11.7 - Salary adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Salary adjustments. 11.7 Section 11.7 Judicial Administration DEPARTMENT OF JUSTICE DEBT COLLECTION Administration of Debt Collection § 11.7 Salary adjustments. The following debts shall not be subject to the salary offset procedures of §...

  15. 28 CFR 11.7 - Salary adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Salary adjustments. 11.7 Section 11.7 Judicial Administration DEPARTMENT OF JUSTICE DEBT COLLECTION Administration of Debt Collection § 11.7 Salary adjustments. The following debts shall not be subject to the salary offset procedures of §...

  16. 28 CFR 11.7 - Salary adjustments.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Salary adjustments. 11.7 Section 11.7 Judicial Administration DEPARTMENT OF JUSTICE DEBT COLLECTION Administration of Debt Collection § 11.7 Salary adjustments. The following debts shall not be subject to the salary offset procedures of §...

  17. 28 CFR 11.7 - Salary adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Salary adjustments. 11.7 Section 11.7 Judicial Administration DEPARTMENT OF JUSTICE DEBT COLLECTION Administration of Debt Collection § 11.7 Salary adjustments. The following debts shall not be subject to the salary offset procedures of §...

  18. 28 CFR 11.7 - Salary adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Salary adjustments. 11.7 Section 11.7 Judicial Administration DEPARTMENT OF JUSTICE DEBT COLLECTION Administration of Debt Collection § 11.7 Salary adjustments. The following debts shall not be subject to the salary offset procedures of §...

  19. 24 CFR 9.155 - Housing adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Housing adjustments. 9.155 Section 9.155 Housing and Urban Development Office of the Secretary, Department of Housing and Urban... THE DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT § 9.155 Housing adjustments. (a) The agency...

  20. 24 CFR 9.155 - Housing adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Housing adjustments. 9.155 Section 9.155 Housing and Urban Development Office of the Secretary, Department of Housing and Urban... THE DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT § 9.155 Housing adjustments. (a) The agency...

  1. 24 CFR 9.155 - Housing adjustments.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Housing adjustments. 9.155 Section 9.155 Housing and Urban Development Office of the Secretary, Department of Housing and Urban... THE DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT § 9.155 Housing adjustments. (a) The agency...

  2. 24 CFR 9.155 - Housing adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Housing adjustments. 9.155 Section 9.155 Housing and Urban Development Office of the Secretary, Department of Housing and Urban... THE DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT § 9.155 Housing adjustments. (a) The agency...

  3. 24 CFR 9.155 - Housing adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Housing adjustments. 9.155 Section 9.155 Housing and Urban Development Office of the Secretary, Department of Housing and Urban... THE DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT § 9.155 Housing adjustments. (a) The agency...

  4. Fuel injection pump with adjustable timing

    SciTech Connect

    Nakamura, H.; Abe, N.

    1987-04-28

    A fuel injection pump is described comprising: a pump body; a plunger disposed in the pump body for reciprocating within the pump body; and a pre-stroke adjusting mechanism disposed in the pump body and operatively connected with the plunger for adjusting an effective pre-stroke of the plunger.

  5. 10 CFR 905.34 - Adjustment provisions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Adjustment provisions. 905.34 Section 905.34 Energy DEPARTMENT OF ENERGY ENERGY PLANNING AND MANAGEMENT PROGRAM Power Marketing Initiative § 905.34 Adjustment...-term firm power contracts only as required to respond to changes in hydrology and river...

  6. 10 CFR 905.34 - Adjustment provisions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Adjustment provisions. 905.34 Section 905.34 Energy DEPARTMENT OF ENERGY ENERGY PLANNING AND MANAGEMENT PROGRAM Power Marketing Initiative § 905.34 Adjustment...-term firm power contracts only as required to respond to changes in hydrology and river...

  7. 10 CFR 905.34 - Adjustment provisions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Adjustment provisions. 905.34 Section 905.34 Energy DEPARTMENT OF ENERGY ENERGY PLANNING AND MANAGEMENT PROGRAM Power Marketing Initiative § 905.34 Adjustment...-term firm power contracts only as required to respond to changes in hydrology and river...

  8. 10 CFR 905.34 - Adjustment provisions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Adjustment provisions. 905.34 Section 905.34 Energy DEPARTMENT OF ENERGY ENERGY PLANNING AND MANAGEMENT PROGRAM Power Marketing Initiative § 905.34 Adjustment...-term firm power contracts only as required to respond to changes in hydrology and river...

  9. Psychological Separation and Adjustment to College.

    ERIC Educational Resources Information Center

    Lapsley, Daniel K.; And Others

    1989-01-01

    Examined relationship between psychological separation and adjustment to college in freshmen (N=130) and upperclassmen (N=123). Found freshmen showed more psychological dependencies on parents than upperclassmen; separation appeared more strongly related to personal/emotional adjustment, particularly functional and emotional independence from…

  10. Divorcing Parents: Guidelines for Promoting Children's Adjustment.

    ERIC Educational Resources Information Center

    Freeman, Kurt A.; Adams, Christina D; Drabman, Ronald S.

    1998-01-01

    There are measures that parents can take to help their children through the often distressing process of parental divorce. Describes the empirical literature regarding issues and factors relevant to children's adjustment to divorce. Provides practical guidelines and suggestions likely to help parents enhance their children's adjustment.…

  11. 7 CFR 2201.30 - Adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Adjustments. 2201.30 Section 2201.30 Agriculture Regulations of the Department of Agriculture (Continued) LOCAL TELEVISION LOAN GUARANTEE BOARD LOCAL TELEVISION LOAN GUARANTEE PROGRAM-PROGRAM REGULATIONS Loan Guarantees § 2201.30 Adjustments. (a) The...

  12. 7 CFR 2201.30 - Adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Adjustments. 2201.30 Section 2201.30 Agriculture Regulations of the Department of Agriculture (Continued) LOCAL TELEVISION LOAN GUARANTEE BOARD LOCAL TELEVISION LOAN GUARANTEE PROGRAM-PROGRAM REGULATIONS Loan Guarantees § 2201.30 Adjustments. (a) The...

  13. Does Fall History Influence Residential Adjustments?

    ERIC Educational Resources Information Center

    Leland, Natalie; Porell, Frank; Murphy, Susan L.

    2011-01-01

    Purpose of the study: To determine whether reported falls at baseline are associated with an older adult's decision to make a residential adjustment (RA) and the type of adjustment made in the subsequent 2 years. Design and Methods: Observations (n = 25,036) were from the Health and Retirement Study, a nationally representative sample of…

  14. 15 CFR 6.6 - Subsequent adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Subsequent adjustments. 6.6 Section 6.6 Commerce and Foreign Trade Office of the Secretary of Commerce CIVIL MONETARY PENALTY INFLATION... once every four years after October 23, 1996, make the inflation adjustment, described in Section...

  15. 15 CFR 6.6 - Subsequent adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Subsequent adjustments. 6.6 Section 6.6 Commerce and Foreign Trade Office of the Secretary of Commerce CIVIL MONETARY PENALTY INFLATION... once every four years after October 23, 1996, make the inflation adjustment, described in Section...

  16. 24 CFR 902.24 - Database adjustment.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false Database adjustment. 902.24 Section 902.24 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED... PUBLIC HOUSING ASSESSMENT SYSTEM Physical Condition Indicator § 902.24 Database adjustment....

  17. 24 CFR 902.24 - Database adjustment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Database adjustment. 902.24 Section 902.24 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED... PUBLIC HOUSING ASSESSMENT SYSTEM Physical Condition Indicator § 902.24 Database adjustment....

  18. 24 CFR 902.24 - Database adjustment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Database adjustment. 902.24 Section 902.24 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED... PUBLIC HOUSING ASSESSMENT SYSTEM Physical Condition Indicator § 902.24 Database adjustment....

  19. 24 CFR 902.24 - Database adjustment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Database adjustment. 902.24 Section 902.24 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED... PUBLIC HOUSING ASSESSMENT SYSTEM Physical Condition Indicator § 902.24 Database adjustment....

  20. A Digital Game for International Students' Adjustment

    ERIC Educational Resources Information Center

    Bisadi, Maryam; Chua, Alton Y. K; Keong, Lee Chu

    2013-01-01

    Although digital games have been developed for various subject areas, little attention has been focused on using digital games to address international students' adjustment issues. For this reason, this paper endeavors to explore the use of a digital game in facilitating international students acquire adjustment-related information. Specifically,…

  1. Adjustable Optical Mount Is More Rigid

    NASA Technical Reports Server (NTRS)

    Asbury, Bill G.; Coombs, David S.; Jones, Irby W.; Moore, Alvah S., Jr.

    1994-01-01

    Improved mount for lens or mirror in laser offers rigidity similar to that of nonadjustable optical mount. In comparison with older adjustable optical mounts, this one less susceptible to movements and distortions caused by vibrations and by thermal expansions and contractions. Mount contains neither adjustment rods (which grow or shrink as temperature varies) nor springs (which transmit vibrations to mounted optic).

  2. Religiousity, Spirituality and Adolescents' Self-Adjustment

    ERIC Educational Resources Information Center

    Japar, Muhammad; Purwati

    2014-01-01

    Religiuosity, spirituality, and adolescents' self-adjustment. The objective of this study is to test the correlation among religiosity, spirituality and adolescents' self-adjustment. A quantitative approach was employed in this study. Data were collected from 476 junior high schools students of 13 State Junior High Schools and one Junior High…

  3. 15 CFR 6.5 - Effective date of adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... INFLATION ADJUSTMENTS § 6.5 Effective date of adjustments. The adjustments made by § 6.4 of this part, of... December 11, 2008, and before the effective date of any future inflation adjustment thereto made...

  4. 15 CFR 6.5 - Effective date of adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... INFLATION ADJUSTMENTS § 6.5 Effective date of adjustments. The adjustments made by § 6.4 of this part, of... December 11, 2008, and before the effective date of any future inflation adjustment thereto made...

  5. The ACS Nearby Galaxy Survey Treasury

    NASA Astrophysics Data System (ADS)

    Dalcanton, Julianne; Williams, B.; Gogarten, S.; Weisz, D.; Skillman, E.; Seth, A.; ANGST Team

    2007-12-01

    The ACS Nearby Galaxy Survey Treasury program (ANGST) is a program to measure photometry for millions of stars in a volume limited sample of 70 nearby galaxies. With this data set, we are deriving spatially resolved star formation histories for both dwarfs and spirals in the local volume. I will highlight initial results from the survey, including ancient star formation histories for massive spirals, halos around dwarf galaxies, spatially-resolved star formation histories in dwarfs and spirals, and the detection of variable stars. I will also discuss the ANGST involved with switching to WFPC2. This program is funded by NASA grant HST GO-10915, administered by STScI.

  6. Nonlinear studies of AC electrokinetic micropumps

    NASA Astrophysics Data System (ADS)

    Bruus, Henrik; Olesen, Laurits H.; Ajdari, Armand

    2006-03-01

    Recent experiments have demonstrated that AC electrokinetic micropumps permit integrable, local, and fast pumping (velocities ˜ mm/s) with low driving voltage of a few volts only. However, they also displayed many quantitative and qualitative discrepancies with existing theories. We therefore extend the latter theories to account for three experimentally relevant effects: (i) vertical confinement of the pumping channel, (ii) Faradaic currents from electrochemical reactions at the electrodes, and (iii) nonlinear surface capacitance of the Debye layer. We report here that these effects indeed affect the pump performance in a way that we can rationalize by physical arguments.

  7. Inverse ac Josephson effect at terahertz frequencies

    NASA Astrophysics Data System (ADS)

    Danchi, W. C.; Golightly, W. J.; Sutton, E. C.

    1989-04-01

    Using the Werthamer (1966) theory of superconducting tunnel junctions, it is shown that zero-crossing ac Josephson steps can occur at frequencies much higher than those expected previously, as long as the voltage waveform is nearly sinusoidal. Limits on the amount of permitted rounding of the Riedel (1964) peak were derived from analytical calculations, and numerical frequency-domain and time-domain computations for realistic junctions were carried out, yielding support for these limits. It is shown that previous arguments that zero-crossing steps could never be observed above the value of half the gap voltage are incorrect, due to the neglect of the Riedel peak.

  8. AC/DC Power Systems with Applications for future Lunar/Mars base and Crew Exploration Vehicle

    NASA Technical Reports Server (NTRS)

    Chowdhury, Badrul H.

    2005-01-01

    redundancies and including emergency generators on both ac and dc sides is proposed. The generation frequency is 400 Hz mostly because of the technology maturity at this frequency in the aerospace industry. Power will be distributed to several ac load distribution buses through solid state variable speed, constant frequency converters on the ac side. A segmented dc ring bus supplied from ac/dc converters and with the capability of connecting/disconnecting the segments will supply power to multiple de load distribution buses. The system will have the capability of reverse flow from dc to ac side in the case of an extreme emergency on the main ac generation side.

  9. High Speed Flow in Tubes

    DTIC Science & Technology

    1987-04-14

    variables such as density or pressure are assumed to depend only on time and not on position along the tube so that only some of the 1-D effects are...ideal gas law). 2) The local linear burning rate (rb) depends on the spatial- average pressure within the tube assembly. 3) The ratio of specific... depends on local pressure . 3) Case AD is the same as case AC except that the ratio of specific heats is no longer constant (i.e., Eq. (2.20) is used to

  10. Parametric Adjustments to the Rankine Vortex Wind Model for Gulf of Mexico Hurricanes

    DTIC Science & Technology

    2012-11-01

    Gulf of Mexico hurricanes show considerable differences between the resulting wind speeds and data. The differences are used to guide the development of adjustment factors to improve the wind fields resulting from the Rankine Vortex model. The corrected model shows a significant improvement in the shape, size, and wind speed contours for 14 out of 17 hurricanes examined. The effect on wave fields resulting from the original and modified wind fields are on the order of 4 m, which is important for the estimation of extreme wave

  11. Does an active adjustment of aerodynamic drag make sense?

    NASA Astrophysics Data System (ADS)

    Maciejewski, Marek

    2016-09-01

    The article concerns evaluation of the possible impact of the gap between the tractor and semitrailer on the aerodynamic drag coefficient. The aim here is not to adjust this distance depending on the geometrical shape of the tractor and trailer, but depending solely on the speed of articulated vehicle. All the tests have form of numerical simulations. The method of simulation is briefly explained in the article. It considers various issues such as the range and objects of tests as well as the test conditions. The initial (pre-adaptive) and final (after adaptation process) computational meshes have been presented as illustrations. Some of the results have been presented in the form of run chart showing the change of value of aerodynamic drag coefficients in time, for different geometric configurations defined by a clearance gap between the tractor and semitrailer. The basis for a detailed analysis and conclusions were the averaged (in time) aerodynamic drag coefficients as a function of the clearance gap.

  12. Electrospinning of aligned fibers with adjustable orientation using auxiliary electrodes

    NASA Astrophysics Data System (ADS)

    Arras, Matthias M. L.; Grasl, Christian; Bergmeister, Helga; Schima, Heinrich

    2012-06-01

    A conventional electrospinning setup was upgraded by two turnable plate-like auxiliary high-voltage electrodes that allowed aligned fiber deposition in adjustable directions. Fiber morphology was analyzed by scanning electron microscopy and attenuated total reflection Fourier transform infrared spectroscopy (FTIR-ATR). The auxiliary electric field constrained the jet bending instability and the fiber deposition became controllable. At target speeds of 0.9 m s-1 90% of the fibers had aligned within 2°, whereas the angular spread was 70° without the use of auxiliary electrodes. It was even possible to orient fibers perpendicular to the rotational direction of the target. The fiber diameter became smaller and its distribution narrower, while according to the FTIR-ATR measurement the molecular orientation of the polymer was unaltered. This study comprehensively documents the feasibility of directed fiber deposition and offers an easy upgrade to existing electrospinning setups.

  13. Do Speed Cameras Reduce Collisions?

    PubMed Central

    Skubic, Jeffrey; Johnson, Steven B.; Salvino, Chris; Vanhoy, Steven; Hu, Chengcheng

    2013-01-01

    We investigated the effects of speed cameras along a 26 mile segment in metropolitan Phoenix, Arizona. Motor vehicle collisions were retrospectively identified according to three time periods – before cameras were placed, while cameras were in place and after cameras were removed. A 14 mile segment in the same area without cameras was used for control purposes. Five cofounding variables were eliminated. In this study, the placement or removal of interstate highway speed cameras did not independently affect the incidence of motor vehicle collisions. PMID:24406979

  14. Speeding chemical reactions by focusing.

    PubMed

    Lacasta, A M; Ramírez-Piscina, L; Sancho, J M; Lindenberg, K

    2013-04-14

    We present numerical results for a chemical reaction of colloidal particles which are transported by a laminar fluid and are focused by periodic obstacles in such a way that the two components are well mixed and consequently the chemical reaction is speeded up. The roles of the various system parameters (diffusion coefficients, reaction rate, and obstacles sizes) are studied. We show that focusing speeds up the reaction from the diffusion limited rate ∼t(-1/2) to very close to the perfect mixing rate, ∼t(-1).

  15. Speeding chemical reactions by focusing

    NASA Astrophysics Data System (ADS)

    Lacasta, A. M.; Ramírez-Piscina, L.; Sancho, J. M.; Lindenberg, K.

    2013-04-01

    We present numerical results for a chemical reaction of colloidal particles which are transported by a laminar fluid and are focused by periodic obstacles in such a way that the two components are well mixed and consequently the chemical reaction is speeded up. The roles of the various system parameters (diffusion coefficients, reaction rate, and obstacles sizes) are studied. We show that focusing speeds up the reaction from the diffusion limited rate ˜t-1/2 to very close to the perfect mixing rate, ˜t-1.

  16. Processing speed differences between 70- and 83-year-olds matched on childhood IQ.

    PubMed

    Deary, Ian J; Ritchie, Stuart J

    2016-01-01

    Processing speed is an important human cognitive capability that might underlie differences in other cognitive skills and their aging. We aimed to test aging-related processing speed differences using a novel cross-sectional design that adjusted for cognitive ability tested in youth. We examined aging differences on three different ways of assessing processing speed: psychometric, experimental, and psychophysical. We compared large narrow-age cohorts of 70- and 83-year-old people who were matched for cognitive ability in childhood. There were decrements of substantial effect size in all processing speed assessments in the older group that were not accounted for by prior cognitive ability, health, or fitness differences, though these factors also contributed to processing speed differences. These findings confirm age-related cognitive slowing using an unusual research design, and provide evidence against recent theories characterizing aging-related cognitive decline as a myth.

  17. Ac irreversibility line of bismuth-based high temperature superconductors

    SciTech Connect

    Mehdaoui, A.; Beille, J.; Berling, D.; Loegel, B.; Noudem, J.G.; Tournier, R.

    1997-09-01

    We discuss the magnetic properties of lead doped Bi-2223 bulk samples obtained through combined magnetic melt texturing and hot pressing (MMTHP). The ac complex susceptibility measurements are achieved over a broad ac field range (1 Oe{lt}h{sub ac}{lt}100 Oe) and show highly anisotropic properties. The intergranular coupling is improved in the direction perpendicular to the applied stress and magnetic field direction, and an intragranular loss peak is observed for the first time. A comparison is made with other bismuth-based compounds and it is shown that the MMTHP process shifts the ac irreversibility line (ac IL) toward higher fields. It is also shown that all the ac IL{close_quote}s for quasi 2D bismuth-based compounds show a nearly quadratic temperature dependence and deviate therefore strongly from the linear behavior observed in quasi 3D compounds and expected from a critical state model.{copyright} {ital 1997 Materials Research Society.}

  18. Cross-Cultural Adjustment of Chinese Students in Japan: School Adjustment and Educational Support

    ERIC Educational Resources Information Center

    Li, Yuan Xiang; Sano, Hideki; Ahn, Ruth

    2013-01-01

    This study investigates Chinese immigrant students' cross-cultural and school adjustment issues in Japanese schools. Using a quantitative method, a survey which collected students' demographic information, cross-cultural adjustment, and school adjustment questions was administered to 143 Chinese junior high and high school students in Tokyo and…

  19. 49 CFR 393.53 - Automatic brake adjusters and brake adjustment indicators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... indicators. 393.53 Section 393.53 Transportation Other Regulations Relating to Transportation (Continued... brake adjustment indicators. (a) Automatic brake adjusters (hydraulic brake systems). Each commercial... vehicle at the time it was manufactured. (c) Brake adjustment indicator (air brake systems). On...

  20. 49 CFR 393.53 - Automatic brake adjusters and brake adjustment indicators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... brake adjustment indicators. (a) Automatic brake adjusters (hydraulic brake systems). Each commercial motor vehicle manufactured on or after October 20, 1993, and equipped with a hydraulic brake system, shall meet the automatic brake adjustment system requirements of Federal Motor Vehicle Safety...

  1. Electrothermally driven flows in ac electrowetting.

    PubMed

    García-Sánchez, Pablo; Ramos, Antonio; Mugele, Frieder

    2010-01-01

    Mixing within sessile drops can be enhanced by generating internal flow patterns using ac electrowetting. While for low ac frequencies, the flow patterns have been attributed to oscillations of the drop surface, we provide here the driving mechanism of the hitherto unexplained high-frequency flows. We show that: (1) the electric field in the liquid bulk becomes important, leading to energy dissipation due to Joule heating and a temperature increase of several degrees Celsius, and (2) the fluid flow at these frequencies is generated by electrothermal effect, i.e., gradients in temperature give rise to gradients in conductivity and permittivity, the electric field acting on these inhomogeneities induces an electrical body force that generates the flow. We solved numerically the equations for the electric, temperature and flow fields. The temperature is obtained from a convection-diffusion equation where Joule heating is introduced as a source term. From the solution of the electric field and the temperature, we compute the electrical force that acts as a body force in Stokes equations. Our numerical results agree with previous experimental observations.

  2. Cascading failures in ac electricity grids.

    PubMed

    Rohden, Martin; Jung, Daniel; Tamrakar, Samyak; Kettemann, Stefan

    2016-09-01

    Sudden failure of a single transmission element in a power grid can induce a domino effect of cascading failures, which can lead to the isolation of a large number of consumers or even to the failure of the entire grid. Here we present results of the simulation of cascading failures in power grids, using an alternating current (AC) model. We first apply this model to a regular square grid topology. For a random placement of consumers and generators on the grid, the probability to find more than a certain number of unsupplied consumers decays as a power law and obeys a scaling law with respect to system size. Varying the transmitted power threshold above which a transmission line fails does not seem to change the power-law exponent q≈1.6. Furthermore, we study the influence of the placement of generators and consumers on the number of affected consumers and demonstrate that large clusters of generators and consumers are especially vulnerable to cascading failures. As a real-world topology, we consider the German high-voltage transmission grid. Applying the dynamic AC model and considering a random placement of consumers, we find that the probability to disconnect more than a certain number of consumers depends strongly on the threshold. For large thresholds the decay is clearly exponential, while for small ones the decay is slow, indicating a power-law decay.

  3. Cascading failures in ac electricity grids

    NASA Astrophysics Data System (ADS)

    Rohden, Martin; Jung, Daniel; Tamrakar, Samyak; Kettemann, Stefan

    2016-09-01

    Sudden failure of a single transmission element in a power grid can induce a domino effect of cascading failures, which can lead to the isolation of a large number of consumers or even to the failure of the entire grid. Here we present results of the simulation of cascading failures in power grids, using an alternating current (AC) model. We first apply this model to a regular square grid topology. For a random placement of consumers and generators on the grid, the probability to find more than a certain number of unsupplied consumers decays as a power law and obeys a scaling law with respect to system size. Varying the transmitted power threshold above which a transmission line fails does not seem to change the power-law exponent q ≈1.6 . Furthermore, we study the influence of the placement of generators and consumers on the number of affected consumers and demonstrate that large clusters of generators and consumers are especially vulnerable to cascading failures. As a real-world topology, we consider the German high-voltage transmission grid. Applying the dynamic AC model and considering a random placement of consumers, we find that the probability to disconnect more than a certain number of consumers depends strongly on the threshold. For large thresholds the decay is clearly exponential, while for small ones the decay is slow, indicating a power-law decay.

  4. Amorphous force transducers in ac applications

    NASA Astrophysics Data System (ADS)

    Meydan, T.; Overshott, K. J.

    1982-11-01

    The high stress sensitivity and high yield stress properties of amorphous ribbon materials make them suitable for magnetic sensors and tranducer applications. Recently the authors have shown that ac systems eliminate the offset voltage and drift problems of the previously published dc systems. Further investigations proved that these transducers could be operated with a linear characteristic up to 1000 g in multiwrap toroidal configurations. The cause of the transducing behavior of the materials was proved to be variation of permeability with stress. It was previously suggested that the optimum operating frequency of the ac transducers is dependent on the physical configuration of the core. Further investigations have shown that the optimum operating frequency is linearly dependent on the amplitude of the input signal to the transducer. Double-core systems have been previously described in the literature where one core acts as a dummy core and the force is applied to the active core. The disadvantage of the double-core system is that aging of the active core changes the performance of the transducer by as much as 10%. A new system will be presented which uses an accurate analog memory to reduce the ageing effect to a fraction of one percent.

  5. AC impedance analysis of polypyrrole thin films

    NASA Technical Reports Server (NTRS)

    Penner, Reginald M.; Martin, Charles R.

    1987-01-01

    The AC impedance spectra of thin polypyrrole films were obtained at open circuit potentials from -0.4 to 0.4 V vs SCE. Two limiting cases are discussed for which simplified equivalent circuits are applicable. At very positive potentials, the predominantly nonfaradaic AC impedance of polypyrrole is very similar to that observed previously for finite porous metallic films. Modeling of the data with the appropriate equivalent circuit permits effective pore diameter and pore number densities of the oxidized film to be estimated. At potentials from -0.4 to -0.3 V, the polypyrrole film is essentially nonelectronically conductive and diffusion of polymer oxidized sites with their associated counterions can be assumed to be linear from the film/substrate electrode interface. The equivalent circuit for the polypyrrole film at these potentials is that previously described for metal oxide, lithium intercalation thin films. Using this model, counterion diffusion coefficients are determined for both semi-infinite and finite diffusion domains. In addition, the limiting low frequency resistance and capacitance of the polypyrrole thin fims was determined and compared to that obtained previously for thicker films of the polymer. The origin of the observed potential dependence of these low frequency circuit components is discussed.

  6. Transport AC Losses in Striated YBCO Coated Conductors (Postprint)

    DTIC Science & Technology

    2012-02-01

    AFRL-RZ-WP-TP-2012-0124 TRANSPORT AC LOSSES IN STRIATED YBCO COATED CONDUCTORS (POSTPRINT) G.A. Levin and P.N. Barnes Mechanical Energy...TRANSPORT AC LOSSES IN STRIATED YBCO COATED CONDUCTORS (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...2006. 14. ABSTRACT DC current-voltage characteristics and transport ac losses of striated and non-striated Y1Ba2Cu3O7-δ ( YBCO ) coated conductors

  7. An Inexpensive and Versatile Version of Kundt's Tube for Measuring the Speed of Sound in Air

    ERIC Educational Resources Information Center

    Papacosta, Pangratios; Linscheid, Nathan

    2016-01-01

    Experiments that measure the speed of sound in air are common in high schools and colleges. In the Kundt's tube experiment, a horizontal air column is adjusted until a resonance mode is achieved for a specific frequency of sound. When this happens, the cork dust in the tube is disturbed at the displacement antinode regions. The location of the…

  8. Overall impact of speed-related initiatives and factors on crash outcomes.

    PubMed

    D'Elia, A; Newstead, S; Cameron, M

    2007-01-01

    From December 2000 until July 2002 a package of speed-related initiatives and factors took place in Victoria, Australia. The broad aim of this study was to evaluate the overall impact of the package on crash outcomes. Monthly crash counts and injury severity proportions were assessed using Poisson and logistic regression models respectively. The model measured the overall effect of the package after adjusting as far as possible for non-speed road safety initiatives and socio-economic factors. The speed-related package was associated with statistically significant estimated reductions in casualty crashes and suggested reductions in injury severity with trends towards increased reductions over time. From December 2000 until July 2002, three new speed enforcement initiatives were implemented in Victoria, Australia. These initiatives were introduced in stages and involved the following key components: More covert operations of mobile speed cameras, including flash-less operations; 50% increase in speed camera operating hours; and lowering of cameras' speed detection threshold. In addition, during the period 2001 to 2002, the 50 km/h General Urban Speed Limit (GUSL) was introduced (January 2001), there was an increase in speed-related advertising including the "Wipe Off 5" campaign, media announcements were made related to the above enforcement initiatives and there was a speeding penalty restructure. The above elements combine to make up a package of speed-related initiatives and factors. The package represents a broad, long term program by Victorian government agencies to reduce speed based on three linked strategies: more intensive Police enforcement of speed limits to deter potential offenders, i.e. the three new speed enforcement initiatives just described - supported by higher penalties; a reduction in the speed limit on local streets throughout Victoria from 60 km/h to 50 km/h; and provision of information using the mass media (television, radio and billboard) to

  9. Towards an "All Speed" Unstructured Upwind Scheme

    NASA Technical Reports Server (NTRS)

    Loh, Ching Y.; Jorgenson, Philip C.E.

    2009-01-01

    In the authors previous studies [1], a time-accurate, upwind finite volume method (ETAU scheme) for computing compressible flows on unstructured grids was proposed. The scheme is second order accurate in space and time and yields high resolution in the presence of discontinuities. The scheme features a multidimensional limiter and multidimensional numerical dissipation. These help to stabilize the numerical process and to overcome the annoying pathological behaviors of upwind schemes. In the present paper, it will be further shown that such multidimensional treatments also lead to a nearly all-speed or Mach number insensitive upwind scheme. For flows at very high Mach number, e.g., 10, local numerical instabilities or the pathological behaviors are suppressed, while for flows at very low Mach number, e.g., 0.02, computation can be directly carried out without invoking preconditioning. For flows in different Mach number regimes, i.e., low, medium, and high Mach numbers, one only needs to adjust one or two parameters in the scheme. Several examples with low and high Mach numbers are demonstrated in this paper. Thus, the ETAU scheme is applicable to a broad spectrum of flow regimes ranging from high supersonic to low subsonic, appropriate for both CFD (computational fluid dynamics) and CAA (computational aeroacoustics).

  10. Airplane tracking documents the fastest flight speeds recorded for bats

    PubMed Central

    Kunz, Thomas H.; Dechmann, Dina K. N.; Swartz, Sharon M.; Wikelski, Martin

    2016-01-01

    The performance capabilities of flying animals reflect the interplay of biomechanical and physiological constraints and evolutionary innovation. Of the two extant groups of vertebrates that are capable of powered flight, birds are thought to fly more efficiently and faster than bats. However, fast-flying bat species that are adapted for flight in open airspace are similar in wing shape and appear to be similar in flight dynamics to fast-flying birds that exploit the same aerial niche. Here, we investigate flight behaviour in seven free-flying Brazilian free-tailed bats (Tadarida brasiliensis) and report that the maximum ground speeds achieved exceed speeds previously documented for any bat. Regional wind modelling indicates that bats adjusted flight speeds in response to winds by flying more slowly as wind support increased and flying faster when confronted with crosswinds, as demonstrated for insects, birds and other bats. Increased frequency of pauses in wing beats at faster speeds suggests that flap-gliding assists the bats' rapid flight. Our results suggest that flight performance in bats has been underappreciated and that functional differences in the flight abilities of birds and bats require re-evaluation. PMID:28018618

  11. Airplane tracking documents the fastest flight speeds recorded for bats.

    PubMed

    McCracken, Gary F; Safi, Kamran; Kunz, Thomas H; Dechmann, Dina K N; Swartz, Sharon M; Wikelski, Martin

    2016-11-01

    The performance capabilities of flying animals reflect the interplay of biomechanical and physiological constraints and evolutionary innovation. Of the two extant groups of vertebrates that are capable of powered flight, birds are thought to fly more efficiently and faster than bats. However, fast-flying bat species that are adapted for flight in open airspace are similar in wing shape and appear to be similar in flight dynamics to fast-flying birds that exploit the same aerial niche. Here, we investigate flight behaviour in seven free-flying Brazilian free-tailed bats (Tadarida brasiliensis) and report that the maximum ground speeds achieved exceed speeds previously documented for any bat. Regional wind modelling indicates that bats adjusted flight speeds in response to winds by flying more slowly as wind support increased and flying faster when confronted with crosswinds, as demonstrated for insects, birds and other bats. Increased frequency of pauses in wing beats at faster speeds suggests that flap-gliding assists the bats' rapid flight. Our results suggest that flight performance in bats has been underappreciated and that functional differences in the flight abilities of birds and bats require re-evaluation.

  12. Role of Osmotic Adjustment in Plant Productivity

    SciTech Connect

    Gebre, G.M.

    2001-01-11

    Successful implementation of short rotation woody crops requires that the selected species and clones be productive, drought tolerant, and pest resistant. Since water is one of the major limiting factors in poplar (Populus sp.) growth, there is little debate for the need of drought tolerant clones, except on the wettest of sites (e.g., lower Columbia River delta). Whether drought tolerance is compatible with productivity remains a debatable issue. Among the many mechanisms of drought tolerance, dehydration postponement involves the maintenance of high leaf water potential due to, for example, an adequate root system. This trait is compatible with productivity, but requires available soil moisture. When the plant leaf water potential and soil water content decline, the plant must be able to survive drought through dehydration tolerance mechanisms, such as low osmotic potential or osmotic adjustment. Osmotic adjustment and low osmotic potential are considered compatible with growth and yield because they aid in the maintenance of leaf turgor. However, it has been shown that turgor alone does not regulate cell expansion or stomatal conductance and, therefore, the role of osmotic adjustment is debated. Despite this finding, osmotic adjustment has been correlated with grain yield in agronomic crop species, and gene markers responsible for osmotic adjustment are being investigated to improve drought tolerance in productive progenies. Although osmotic adjustment and low osmotic potentials have been investigated in several forest tree species, few studies have investigated the relationship between osmotic adjustment and growth. Most of these studies have been limited to greenhouse or container-grown plants. Osmotic adjustment and rapid growth have been specifically associated in Populus and black spruce (Picea mariuna (Mill.) B.S.P.) progenies. We tested whether these relationships held under field conditions using several poplar clones. In a study of two hybrid poplar

  13. Fabrication of alumina films with laminated structures by ac anodization.

    PubMed

    Segawa, Hiroyo; Okano, Hironaga; Wada, Kenji; Inoue, Satoru

    2014-02-01

    Anodization techniques by alternating current (ac) are introduced in this review. By using ac anodization, laminated alumina films are fabricated. Different types of alumina films consisting of 50-200 nm layers were obtained by varying both the ac power supply and the electrolyte. The total film thickness increased with an increase in the total charge transferred. The thickness of the individual layers increased with the ac voltage; however, the anodization time had little effect on the film thickness. The laminated alumina films resembled the nacre structure of shells, and the different morphologies exhibited by bivalves and spiral shells could be replicated by controlling the rate of increase of the applied potentials.

  14. Fabrication of alumina films with laminated structures by ac anodization

    NASA Astrophysics Data System (ADS)

    Segawa, Hiroyo; Okano, Hironaga; Wada, Kenji; Inoue, Satoru

    2014-02-01

    Anodization techniques by alternating current (ac) are introduced in this review. By using ac anodization, laminated alumina films are fabricated. Different types of alumina films consisting of 50-200 nm layers were obtained by varying both the ac power supply and the electrolyte. The total film thickness increased with an increase in the total charge transferred. The thickness of the individual layers increased with the ac voltage; however, the anodization time had little effect on the film thickness. The laminated alumina films resembled the nacre structure of shells, and the different morphologies exhibited by bivalves and spiral shells could be replicated by controlling the rate of increase of the applied potentials.

  15. Study of AC electrical conduction mechanisms in an epoxy polymer

    NASA Astrophysics Data System (ADS)

    Jilani, Wissal; Mzabi, Nissaf; Gallot-Lavallée, Olivier; Fourati, Najla; Zerrouki, Chouki; Zerrouki, Rachida; Guermazi, Hajer

    2015-11-01

    The AC conductivity of an epoxy resin was investigated in the frequency range 10^{-1} - 106 Hz at temperatures ranging from -100 to 120 °C. The frequency dependence of σ_{ac} was described by the law: σ_{ac}=ω \\varepsilon0\\varepsilon^''_{HN}+Aωs. The study of temperature variation of the exponent (s) reveals two conduction models: the AC conduction dependence upon temperature is governed by the small polaron tunneling mechanism (SPTM) at low temperature (-100 -60 °C) and the correlated barrier hopping (CHB) model at high temperature (80-120 °C).

  16. Experiment on performance of adjustable jet pump

    NASA Astrophysics Data System (ADS)

    Zhu, J. M.; Long, X. P.; Zhang, S. B.; Lu, X.

    2012-11-01

    When the water level of upper or lower reaches of hydraulic power station changes, the adjustable jet pump which is different from traditional fixed jet pump can maintain stable pressure and flow rate for the system of technical water supply of hydraulic power plant. The model test indicates that the efficiency of the adjustable jet pump is slightly lower than fixed jet pump near rating operation point. With the decrease of opening degree, both efficiencies are more and more close to each other. The fundamental performance of I-type adjustable jet pump is better than II-type and the cavitation performance of I-type adjustable jet pump is worse than II-type. Test data also indicate that the performance of adjustable jet pump is very different from fixed jet pump, so the theory of fixed jet pump is not able to be copied to adjustable jet pump. It is necessary to farther study on the performance of the adjustable jet pump. This paper has reference value for analogous design of system of circulation water supply to turbine units in hydraulic power station.

  17. Running in the real world: adjusting leg stiffness for different surfaces

    NASA Technical Reports Server (NTRS)

    Ferris, D. P.; Louie, M.; Farley, C. T.

    1998-01-01

    A running animal coordinates the actions of many muscles, tendons, and ligaments in its leg so that the overall leg behaves like a single mechanical spring during ground contact. Experimental observations have revealed that an animal's leg stiffness is independent of both speed and gravity level, suggesting that it is dictated by inherent musculoskeletal properties. However, if leg stiffness was invariant, the biomechanics of running (e.g. peak ground reaction force and ground contact time) would change when an animal encountered different surfaces in the natural world. We found that human runners adjust their leg stiffness to accommodate changes in surface stiffness, allowing them to maintain similar running mechanics on different surfaces. These results provide important insight into mechanics and control of animal locomotion and suggest that incorporating an adjustable leg stiffness in the design of hopping and running robots is important if they are to match the agility and speed of animals on varied terrain.

  18. The Art Speed of Light

    NASA Astrophysics Data System (ADS)

    Wojcik, Jan

    2006-03-01

    The Roman poet Horace predicted correctly his phrase aere perennius, would last ``longer than bronze'' because the Ode he wrote travels to the eye at nearly the speed of light regardless of the rate of the decay of the paper it's written on. John Keats's 19th century Ode predicted correctly the youthful figures he saw on a bronze age Grecian Urn moved in ``slow time'' aging little from the time of painting to the time of his viewing in the British museum-and to ours today of the same urn. The youthful images of the Keystone Kops have aged slower than their twins-- their mortal actors. Discoveries about light's speed occurred synchronously with the engineering of telegraph and radio transmissions in the 19th century-which allowed anyone an experience of what Physics had discovered. Einstein's privotal papers appeared in the same year as the first feature film shot and transmitted at the speed of light regardless of the aging of the film stock. Experiencing the light-like speed of art in Keat's ode, Cubism, Bob and Ray's radio, the Keystone Kops provides an aesthetic, visceral understanding of Einstein's Twin's Paradox about the dilation of time.

  19. The speed of Galileon gravity

    NASA Astrophysics Data System (ADS)

    Brax, Philippe; Burrage, Clare; Davis, Anne-Christine

    2016-03-01

    We analyse the speed of gravitational waves in coupled Galileon models with an equation of state ωphi=-1 now and a ghost-free Minkowski limit. We find that the gravitational waves propagate much faster than the speed of light unless these models are small perturbations of cubic Galileons and the Galileon energy density is sub-dominant to a dominant cosmological constant. In this case, the binary pulsar bounds on the speed of gravitational waves can be satisfied and the equation of state can be close to -1 when the coupling to matter and the coefficient of the cubic term of the Galileon Lagrangian are related. This severely restricts the allowed cosmological behaviour of Galileon models and we are forced to conclude that Galileons with a stable Minkowski limit cannot account for the observed acceleration of the expansion of the universe on their own. Moreover any sub-dominant Galileon component of our universe must be dominated by the cubic term. For such models with gravitons propagating faster than the speed of light, the gravitons become potentially unstable and could decay into photon pairs. They could also emit photons by Cerenkov radiation. We show that the decay rate of such speedy gravitons into photons and the Cerenkov radiation are in fact negligible. Moreover the time delay between the gravitational signal and light emitted by explosive astrophysical events could serve as a confirmation that a modification of gravity acts on the largest scales of the Universe.

  20. An inexpensive vehicle speed detector

    NASA Technical Reports Server (NTRS)

    Broussard, P., Jr.

    1973-01-01

    Low-power minicomputer can plug into automobile cigarette lighter. It measures time it takes observed car to travel premeasured distance and provides immediate readout of speed. Potentially, detector could be manufactured for less than $200 per unit and would have very low maintenance cost.

  1. High speed multiwire photon camera

    NASA Technical Reports Server (NTRS)

    Lacy, Jeffrey L. (Inventor)

    1991-01-01

    An improved multiwire proportional counter camera having particular utility in the field of clinical nuclear medicine imaging. The detector utilizes direct coupled, low impedance, high speed delay lines, the segments of which are capacitor-inductor networks. A pile-up rejection test is provided to reject confused events otherwise caused by multiple ionization events occuring during the readout window.

  2. High speed multiwire photon camera

    NASA Technical Reports Server (NTRS)

    Lacy, Jeffrey L. (Inventor)

    1989-01-01

    An improved multiwire proportional counter camera having particular utility in the field of clinical nuclear medicine imaging. The detector utilizes direct coupled, low impedance, high speed delay lines, the segments of which are capacitor-inductor networks. A pile-up rejection test is provided to reject confused events otherwise caused by multiple ionization events occurring during the readout window.

  3. Speeding up enzyme engineering computationally.

    PubMed

    Scrutton, Nigel S

    2017-01-01

    Can in silico engineering speed up the delivery of biocatalysts for the burgeoning bioeconomy? In this issue, Kamerlin and coworkers introduce CADEE [Amrein et al. (2017), IUCrJ, 4, 50-64] - a framework for Computer-Aided Directed Evolution of Enzymes - that promises to lessen the burden on 'wet lab' enzymologists when optimizing biocatalysts using laboratory-based directed evolution methods.

  4. The speed of Galileon gravity

    SciTech Connect

    Brax, Philippe; Burrage, Clare; Davis, Anne-Christine E-mail: Clare.Burrage@nottingham.ac.uk

    2016-03-01

    We analyse the speed of gravitational waves in coupled Galileon models with an equation of state ω{sub φ}=−1 now and a ghost-free Minkowski limit. We find that the gravitational waves propagate much faster than the speed of light unless these models are small perturbations of cubic Galileons and the Galileon energy density is sub-dominant to a dominant cosmological constant. In this case, the binary pulsar bounds on the speed of gravitational waves can be satisfied and the equation of state can be close to -1 when the coupling to matter and the coefficient of the cubic term of the Galileon Lagrangian are related. This severely restricts the allowed cosmological behaviour of Galileon models and we are forced to conclude that Galileons with a stable Minkowski limit cannot account for the observed acceleration of the expansion of the universe on their own. Moreover any sub-dominant Galileon component of our universe must be dominated by the cubic term. For such models with gravitons propagating faster than the speed of light, the gravitons become potentially unstable and could decay into photon pairs. They could also emit photons by Cerenkov radiation. We show that the decay rate of such speedy gravitons into photons and the Cerenkov radiation are in fact negligible. Moreover the time delay between the gravitational signal and light emitted by explosive astrophysical events could serve as a confirmation that a modification of gravity acts on the largest scales of the Universe.

  5. Algebra 1's Speed Trap

    ERIC Educational Resources Information Center

    Gupta, Neil Kenneth

    2004-01-01

    Students often look for real-life situations where they can apply the concepts they learn. A project of measuring the speed of moving cars demonstrates that they learn communication skills, teamwork skills, and develop patience specially when work in a group with a common purpose.

  6. The Speeding Car Design Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2009-01-01

    All too often, one reads about high-speed police chases in pursuit of stolen cars that result in death and injury to people and innocent bystanders. Isn't there another way to accomplish the apprehension of the thieves that does not put people at such great risk? This article presents a classroom challenge to use technology to remotely shutdown…

  7. Development of Adjustable Grazing Incidence Optics

    NASA Astrophysics Data System (ADS)

    Reid, Paul B.; Davis, W.; Schwartz, D. A.; Trolier-McKinstry, S.; Wilke, R. H. T.

    2010-03-01

    We report on the development of adjustable grazing incidence optics. We are developing bimorph mirrors for high resolution (sub-arc second) imaging. Bimorph mirrors consist of a thin layer of piezo-electric material deposited on the back surface of a thin (< 0.4 mm) thermally formed glass or electroplated metal segmented mirror. Voltage applied across the thickness of the piezo produces a strain in the plane of the mirror surface. The strain produces bending of the mirror similar to the bi-metallic effect. No reaction structure is necessary, which allows one to densely nest mirror shells for large effective area. A pixilated array of outer electrodes on the piezo material localizes the strain to the particular piezo "pixel.” Mirror figure errors are corrected (on-orbit) via induced localized deformations. We have successfully deposited a 1-micrometer thick layer of the piezo-electric material lead-zirconate-titanate (PZT) on thin glass mirrors. We report on the electrical and mechanical properties of the bimorph mirrors, and mirror requirements. We discuss finite element modeling of bimorph mirrors. In particular, we focus on how a difference in mirror mounting affects the influence functions ( the induced deformations). We are also developing the use of electrostrictive adjusters for moderate resolution (a few arc second) imaging. Electroplated nickel/cobalt full shells are mounted together using the adjusters. The adjusters are arrayed axially and tangentially between shells, with their adjustable dimension in the radial direction. Each shell is adjusted and fixed in place during mirror assembly, starting with the innermost shell. We review finite element modeling of the adjustable optics and the application of the adjustment system to correct manufacturing errors. We discuss initial tests using electrostrictive adjusters to change the shape of flat mirror segments. This work is supported by NASA Contract NNX09AE87G and a grant from the Gordon and Betty Moore

  8. Low Speed Control for Automatic Welding

    NASA Technical Reports Server (NTRS)

    Iceland, W. E.

    1982-01-01

    Amplifier module allows rotating positioner of automatic welding machine to operate at speeds below normal range. Low speeds are precisely regulated by a servomechanism as are normal-range speeds. Addition of module to standard welding machine makes it unnecessary to purchase new equipment for low-speed welding.

  9. 49 CFR 229.117 - Speed indicators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Speed indicators. 229.117 Section 229.117... § 229.117 Speed indicators. (a) After December 31, 1980, each locomotive used as a controlling locomotive at speeds in excess of 20 miles per hour shall be equipped with a speed indicator which is—...

  10. 49 CFR 229.117 - Speed indicators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Speed indicators. 229.117 Section 229.117... § 229.117 Speed indicators. (a) After December 31, 1980, each locomotive used as a controlling locomotive at speeds in excess of 20 miles per hour shall be equipped with a speed indicator which is—...

  11. Sonde Adjust Value-Added Product Technical Report

    SciTech Connect

    Troyan, D

    2012-01-09

    The Sonde Adjust (SONDEADJUST) value-added product (VAP) creates a file that includes all fields from original Atmospheric Radiation Measurement Climate Research Facility (ARM Facility) radiosonde files and contains several value-added fields that provide adjustments related to well-known humidity issues. SONDEADJUST produces data that correct documented biases in radiosonde humidity measurements. Previous efforts towards applying some of these corrections are available via the discontinued PI product sgpsondecorr1miloC1. Unique fields contained within this datastream include smoothed original relative humidity, dry bias corrected relative humidity, and final corrected relative humidity. The smoothed RH field refines the relative humidity from integers-the resolution of the instrument-to fractions of a percent. This profile is then used to calculate the dry bias corrected field. The final correction fixes the time-lag problem and uses the dry-bias field as input into the algorithm. In addition to dry bias, solar heating is another correction that is encompassed in the final corrected RH field. Output from SONDEADJUST differs from the previous RH-corrected datastreams in important ways. First, all three types of ARM radiosondes-Vaisala RS-80, RS-90, and RS-92-are corrected using dedicated procedures and/or parameters. Second, the output variables include all of those found in the original radiosonde file: dry bulb temperature, dewpoint temperature, wind speed, wind direction, eastward wind component, northward wind component, wind status (a Vaisala-produced field used in conjunction with the Loran system), ascent rate, and original relative humidity. Additional humidity fields are smoothed relative humidity, dry biased corrected relative humidity, final ambient relative humidity, and scaled adjusted relative humidity. Third, quality control (QC) flags of the fields from the original radiosonde datastream are brought into the SONDEADJUST output file. Additional QC

  12. Uncovering the Catalytic Direction of Chondroitin AC Exolyase

    PubMed Central

    Yin, Feng-Xin; Wang, Feng-Shan; Sheng, Ju-Zheng

    2016-01-01

    Glycosaminoglycans (GAGs) are polysaccharides that play vital functional roles in numerous biological processes, and compounds belonging to this class have been implicated in a wide variety of diseases. Chondroitin AC lyase (ChnAC) (EC 4.2.2.5) catalyzes the degradation of various GAGs, including chondroitin sulfate and hyaluronic acid, to give the corresponding disaccharides containing an Δ4-unsaturated uronic acid at their non-reducing terminus. ChnAC has been isolated from various bacteria and utilized as an enzymatic tool for study and evaluating the sequencing of GAGs. Despite its substrate specificity and the fact that its crystal structure has been determined to a high resolution, the direction in which ChnAC catalyzes the cleavage of oligosaccharides remain unclear. Herein, we have determined the structural cues of substrate depolymerization and the cleavage direction of ChnAC using model substrates and recombinant ChnAC protein. Several structurally defined oligosaccharides were synthesized using a chemoenzymatic approach and subsequently cleaved using ChnAC. The degradation products resulting from this process were determined by mass spectrometry. The results revealed that ChnAC cleaved the β1,4-glycosidic linkages between glucuronic acid and glucosamine units when these bonds were located on the reducing end of the oligosaccharide. In contrast, the presence of a GlcNAc-α-1,4-GlcA unit at the reducing end of the oligosaccharide prevented ChnAC from cleaving the GalNAc-β1,4-GlcA moiety located in the middle or at the non-reducing end of the chain. These interesting results therefore provide direct proof that ChnAC cleaves oligosaccharide substrates from their reducing end toward their non-reducing end. This conclusion will therefore enhance our collective understanding of the mode of action of ChnAC. PMID:26742844

  13. 76 FR 67500 - Postal Service Price Adjustment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-01

    ... Adjustment Notice states that the overall average for Special Services is a result of large price reductions...; Address Management Services; Caller Service; Change-of-Address Credit Card Authentication; Confirm... Periodicals, Nonprofit and Classroom Periodicals, Science of Agriculture Periodicals advertising...

  14. Adjustable throttle linkage for outboard motors

    SciTech Connect

    Dunham, W.D.; Miller, G.L.

    1986-02-17

    An adjustable throttle linkage is described for use in controlling operation of an internal combustion engine having a carburetor including a pivotable throttle valve, a throttle valve position control member operably connected to the throttle valve and movable so as to control the position of the throttle valve, and a throttle lever for controlling the position of the throttle valve. The adjustable throttle linkage comprises a connecting link having one end connected to one of the throttle lever and the control member, and having a threaded portion, means for adjustably connecting the threaded portion to the other of the throttle lever and the control member. The adjustable connecting means includes a slot in the other of the throttle lever and the control member, and a rotatable member threaded onto the threaded portion and receive in the slot such that rotation of the rotatable member causes relative movement between the link and the other of the throttle lever and the control member.

  15. Multi-Scale 7DOF View Adjustment.

    PubMed

    Cho, Isaac; Li, Jialei; Wartell, Zachary

    2017-02-13

    Multi-scale virtual environments contain geometric details ranging over several orders of magnitude and typically employ out-of-core rendering techniques. When displayed in virtual reality systems this entails using a 7 degree-of-freedom (DOF) view model where view scale is a separate 7th DOF in addition to 6DOF view pose. Dynamic adjustment of this and other view parameters become very important to usability. In this paper, we evaluate how two adjustment techniques interact with uni- and bi-manual 7 degree-of-freedom navigation in DesktopVR and a CAVE. The travel task has two stages, an initial targeted zoom and a detailed geometric inspection. The results show benefits of the auto-adjustments on completion time and stereo fusion issues, but only in certain circumstances. Peculiar view configuration examples show the difficulty of creating robust adjustment rules.

  16. Floating-diffusion electrometer with adjustable sensitivity

    NASA Technical Reports Server (NTRS)

    Tower, John R. (Inventor)

    1989-01-01

    The effective capacitance of the floating diffusion in a floating-diffusion electrometer is modified to adjust electrometer sensitivity. This is done by changing the direct potential applied to a gate electrode proximate to the floating diffusion.

  17. 49 CFR 1135.1 - Quarterly adjustment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... railroad productivity as prescribed in Railroad Cost Recovery Procedures, 1 I.C.C.2d 207 (1984), and any subsequent amendments thereto. In addition, the AAR shall calculate the productivity-adjusted RCAF...

  18. 49 CFR 1135.1 - Quarterly adjustment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... railroad productivity as prescribed in Railroad Cost Recovery Procedures, 1 I.C.C.2d 207 (1984), and any subsequent amendments thereto. In addition, the AAR shall calculate the productivity-adjusted RCAF...

  19. Adjustment to Divorce Through Transactional Analysis

    ERIC Educational Resources Information Center

    Morris, James D.; Prescott, Mary R.

    1976-01-01

    Transactional Analysis in a group facilitates adjustment to divorce. Two case histories highlight the value of TA in conceptualizing the problem areas of each individual and the changes during group therapy. (Author)

  20. Marital Adjustment and Psychological Distress in Japan.

    PubMed

    Li, Angela; Robustelli, Briana L; Whisman, Mark A

    2016-11-01

    This study was conducted to examine the association between marital adjustment and psychological distress in a large, probability sample of married adults in Japan (N = 710) from the Midlife Development in Japan (MIDJA) study. Results indicate that positive and negative dimensions of marital adjustment were significantly associated with dimensional and categorical measures of psychological distress. Furthermore, the associations between marital adjustment and psychological distress remained significant when statistically controlling for neuroticism, quality of friend and family relationships, and demographic variables. These results demonstrate that the well-established association between marital adjustment and psychological distress found in European-American countries is also found in Japan. Findings support continued research on marital functioning and psychological distress in East Asian countries.

  1. AcMNPV ac143 (odv-e18) is essential for mediating budded virus production and is the 30th baculovirus core gene.

    PubMed

    McCarthy, Christina B; Theilmann, David A

    2008-05-25

    Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac143 (odv-e18) is a late gene that encodes for a predicted 9.6 kDa structural protein that locates to the occlusion derived viral envelope and viral induced intranuclear microvesicles [Braunagel, S.C., He, H., Ramamurthy, P., and Summers, M.D. (1996). Transcription, translation, and cellular localization of three Autographa californica nuclear polyhedrosis virus structural proteins: ODV-E18, ODV-E35, and ODV-EC27. Virology 222, 100-114.]. In this study we demonstrate that ac143 is actually a previously unrecognized core gene and that it is essential for mediating budded virus production. To examine the role of ac143 in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an ac143 knockout (KO) virus (AcBAC(ac142)(REP-ac143KO)). Fluorescence and light microscopy showed that infection by AcBAC(ac142)(REP-ac143KO) is limited to a single cell and titration assays confirmed that AcBAC(ac142)(REP-ac143KO) was unable to produce budded virus (BV). Progression to very late phases of the viral infection was evidenced by the development of occlusion bodies in the nuclei of transfected cells. This correlated with the fact that viral DNA replication was unaffected in AcBAC(ac142)(REP-ac143KO) transfected cells. The entire ac143 promoter, which includes three late promoter motifs, is contained within the ac142 open reading frame. Different deletion mutants of this region showed that the integrity of the ac142-ac143 core gene cluster was required for the bacmids to display wild-type patterns of viral replication, BV production and RNA transcription.

  2. AcMNPV ac143 (odv-e18) is essential for mediating budded virus production and is the 30th baculovirus core gene

    SciTech Connect

    McCarthy, Christina B.; Theilmann, David A.

    2008-05-25

    Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac143 (odv-e18) is a late gene that encodes for a predicted 9.6 kDa structural protein that locates to the occlusion derived viral envelope and viral induced intranuclear microvesicles [Braunagel, S.C., He, H., Ramamurthy, P., and Summers, M.D. (1996). Transcription, translation, and cellular localization of three Autographa californica nuclear polyhedrosis virus structural proteins: ODV-E18, ODV-E35, and ODV-EC27. Virology 222, 100-114.]. In this study we demonstrate that ac143 is actually a previously unrecognized core gene and that it is essential for mediating budded virus production. To examine the role of ac143 in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an ac143 knockout (KO) virus (AcBAC{sup ac142REP-ac143KO}). Fluorescence and light microscopy showed that infection by AcBAC{sup ac142REP-ac143KO} is limited to a single cell and titration assays confirmed that AcBAC{sup ac142REP-ac143KO} was unable to produce budded virus (BV). Progression to very late phases of the viral infection was evidenced by the development of occlusion bodies in the nuclei of transfected cells. This correlated with the fact that viral DNA replication was unaffected in AcBAC{sup ac142REP-ac143KO} transfected cells. The entire ac143 promoter, which includes three late promoter motifs, is contained within the ac142 open reading frame. Different deletion mutants of this region showed that the integrity of the ac142-ac143 core gene cluster was required for the bacmids to display wild-type patterns of viral replication, BV production and RNA transcription.

  3. Public Understanding of Chemistry, ACS National Meeting

    NASA Astrophysics Data System (ADS)

    Gettys, Nancy S.

    2000-06-01

    Three public events for area school-aged children were held on Saturday, March 25, 2000, prior to the opening of the 219th National Meeting of the American Chemical Society. All took place at the Moscone Convention Center in downtown San Francisco. The photographs tell the story: the programs were successful and a good time was had by all. Readers may be encouraged to try these ideas in their own area. If so, the local organizers of Carver Kidvention have additional information at www.scvacs.org/Carver/index.html or contact Howard Peters (Santa Clara Valley Section, ACS), peters4pa@aol.com. Additional photos of the Kidvention event may also be seen as supplemental material.

  4. Dielectric relaxation in AC powder electroluminescent devices

    NASA Astrophysics Data System (ADS)

    Zhang, Shuai; Su, Haibin; Tan, Chuan Seng; Wong, Terence Kin Shun; Teo, Ronnie Jin Wah

    2017-01-01

    The dielectric properties of AC powder electroluminescent devices were measured and analyzed using complex impedance spectroscopy to determine the relaxation processes occurring within the devices. The relaxation processes identified were ascribed to the electrode polarization caused by ion accumulation at the electrode/resin interfaces, the Maxwell-Wagner-Sillars effects at the (ZnS or BaTiO3) particle/resin interfaces, and the dipolar reorientation of polymer chains in the resin matrix. Each relaxation process was represented by its corresponding equivalent circuit component. Space charge polarization at the electrodes were represented by a Warburg element, a resistor, and a constant phase element. The resin matrix, ZnS/resin and BaTiO3/resin interfaces could each be modeled by a resistor and a capacitor in parallel. The simulated equivalent circuits for three different printed structures showed good fitting with their experimental impedance results.

  5. Boston ACS Meeting, Chemical Education Program

    NASA Astrophysics Data System (ADS)

    Wildeman, Thomas R.; Torre, Frank; Smist, Julianne

    1998-11-01

    For those of us who had not been to Boston since the last ACS meeting it was surprising to see how vibrant the city was. The shops, restaurants, parks, and other attractions throughout the large inner city area made the meeting most enjoyable. Again, our banquet cruise of the harbor was blessed with excellent weather. The ship went out far enough so that we landlocked people could feel the waves. The entire program had a celebratory tone-two sessions marking the 70th birthday of Glenn Crosby, a memorial symposium celebrating the teaching innovations of Hubert Alyea, and the 75th anniversary of the Journal of Chemical Education (>p 1360). Content issues in upper division chemistry courses as well as general chemistry took up a large portion of the program. Some of the symposia are discussed in this article.

  6. ACS Internal CTE Monitor and Short Darks

    NASA Astrophysics Data System (ADS)

    Ogaz, Sara

    2012-10-01

    This is a continuation of Program 12386 and is to be executed once a cycle for internal CTE and short darks, respectively.INTERNAL CTE MONITOR:The charge transfer efficiency {CTE} of the ACS CCD detectors will decline as damage due to on-orbit radiation exposure accumulates. This degradation will be monitored once a cycle to determine the useful lifetime of the CCDs. All the data for this program is acquired using internal targets {lamps} only, so all of the exposures should be taken during Earth occultation time {but not during SAA passages}. This program emulates the ACS pre-flight ground calibration and post-launch SMOV testing {program 8948}, so that results from each epoch can be directly compared. Extended Pixel Edge Response {EPER} data will be obtained over a range of signal levels for the Wide Field Channel {WFC}. The signal levels are 125, 500, 1620, 5000, 10000, and 60000 electrons at gain 2.Since Cycle 18, this monitoring program was reduced {compared to 11881} considering that there is also an external CTE monitoring program.SHORT DARKS:To improve the pixel-based CTE model at signals below 10 DN, short dark frames are needed to obtain a statistically useful sample of clean, warm pixel trails. This program obtains a set of dark frames for each of the following exposure times: 66 s {60 s for some subarrays} and 339 s. These short darks and the 1040 s darks obtained from the CCD Daily Monitor will sample warm and hot pixels over logarithmically increasing brightness. Subarray short darks were newly added in Cycle 19 to study CTE tails in different subarray readout modes.

  7. ACS Internal CTE Monitor and Short Darks

    NASA Astrophysics Data System (ADS)

    Ogaz, Sara

    2013-10-01

    This is a continuation of Program 13156 and is to be executed once a cycle for internal CTE and short darks, respectively.INTERNAL CTE MONITOR:The charge transfer efficiency {CTE} of the ACS CCD detectors will decline as damage due to on-orbit radiation exposure accumulates. This degradation will be monitored once a cycle to determine the useful lifetime of the CCDs. All the data for this program is acquired using internal targets {lamps} only, so all of the exposures should be taken during Earth occultation time {but not during SAA passages}. This program emulates the ACS pre-flight ground calibration and post-launch SMOV testing {program 8948}, so that results from each epoch can be directly compared. Extended Pixel Edge Response {EPER} data will be obtained over a range of signal levels for the Wide Field Channel {WFC}. The signal levels are 125, 500, 1620, 5000, 10000, and 60000 electrons at gain 2.Since Cycle 18, this monitoring program was reduced {compared to 11881} considering that there is also an external CTE monitoring program.SHORT DARKS:To improve the pixel-based CTE model at signals below 10 DN, short dark frames are needed to obtain a statistically useful sample of clean, warm pixel trails. This program obtains a set of dark frames for each of the following exposure times: 66 s {60 s for some subarrays} and 339 s. These short darks and the 1040 s darks obtained from the CCD Daily Monitor will sample warm and hot pixels over logarithmically increasing brightness. Subarray short darks were added in Cycle 19 to study CTE tails in different subarray readout modes.

  8. ACS Internal CTE Monitor and Short Darks

    NASA Astrophysics Data System (ADS)

    Lian Lim, Pey

    2010-09-01

    INTERNAL CTE MONITOR:The charge transfer efficiency {CTE} of the ACS CCD detectors will decline as damage due to on-orbit radiation exposure accumulates. This degradation will be monitored once a cycle to determine the useful lifetime of the CCDs. All the data for this program is acquired using internal targets {lamps} only, so all of the exposures should be taken during Earth occultation time {but not during SAA passages}. This program emulates the ACS pre-flight ground calibration and post-launch SMOV testing {program 8948}, so that results from each epoch can be directly compared. Extended Pixel Edge Response {EPER} data will be obtained over a range of signal levels for the Wide Field Channel {WFC}. The signal levels are 125, 500, 1620, 5000, 10000, and 60000 electrons at gain 2.In Cycle 18, this monitoring program has been reduced {compared to 11881} considering that there is also an external CTE monitoring program. High Resolution Camera {HRC} is not available for observations. First Pixel Response {FPR} exposures are removed because they only provide serial CTE for WFC, which is not that useful. Pseudo-bias exposures are removed because they are not used. Signal levels 300, 700, 1000, 30000, and 45000.electrons are removed to reduce total orbits. Number of exposures per setting are reduced to 1 only. Amps BC are removed since amp dependence is not an issue for EPER.SHORT DARKS:To improve the pixel-based CTE model at signals below 10 DN, short dark frames are needed to obtain a statistically useful sample of clean, warm pixel trails. This program obtains 9 dark frames for each of the following exposure times: 33 s, 100 s, and 339 s. These short darks and the 1000 s darks obtained from the CCD Daily Monitor will sample warm and hot pixels over logarithmically increasing brightness.This is a continuation of Program 12327 and is to be executed once a cycle.

  9. ACS Internal CTE Monitor and Short Darks

    NASA Astrophysics Data System (ADS)

    Lian Lim, Pey

    2011-10-01

    This is a continuation of Program 12386 and is to be executed once a cycle for internal CTE and short darks, respectively.INTERNAL CTE MONITOR:The charge transfer efficiency {CTE} of the ACS CCD detectors will decline as damage due to on-orbit radiation exposure accumulates. This degradation will be monitored once a cycle to determine the useful lifetime of the CCDs. All the data for this program is acquired using internal targets {lamps} only, so all of the exposures should be taken during Earth occultation time {but not during SAA passages}. This program emulates the ACS pre-flight ground calibration and post-launch SMOV testing {program 8948}, so that results from each epoch can be directly compared. Extended Pixel Edge Response {EPER} data will be obtained over a range of signal levels for the Wide Field Channel {WFC}. The signal levels are 125, 500, 1620, 5000, 10000, and 60000 electrons at gain 2.Since Cycle 18, this monitoring program was reduced {compared to 11881} considering that there is also an external CTE monitoring program.SHORT DARKS:To improve the pixel-based CTE model at signals below 10 DN, short dark frames are needed to obtain a statistically useful sample of clean, warm pixel trails. This program obtains a set of dark frames for each of the following exposure times: 66 s {60 s for some subarrays} and 339 s. These short darks and the 1040 s darks obtained from the CCD Daily Monitor will sample warm and hot pixels over logarithmically increasing brightness. Subarray short darks are newly added in Cycle 19 to study CTE tails in different subarray readout modes.

  10. Are Current Law Enforcement Strategies Associated with a Lower Risk of Repeat Speeding Citations and Crash Involvement? A Longitudinal Study of Speeding Maryland Drivers

    PubMed Central

    Amr, Sania; Braver, Elisa R.; Langenberg, Patricia; Zhan, Min; Smith, Gordon S.; Dischinger, Patricia C.

    2013-01-01

    PURPOSE To determine whether traffic court appearances and different court verdicts were associated with risk of subsequent speeding citations and crashes. METHODS A cohort of 29,754 Maryland drivers ticketed for speeding who either went to court or paid fines by mail in May/June 2003 was followed for 3 years. Drivers appearing in court were categorized by verdicts: 1) not guilty, 2) suspension of prosecution/no prosecution (STET/NP), 3) case dismissed, 4) probation before judgment and fines (PBJ), or 5) fines and demerit points. Cox proportional hazard models were used to estimate adjusted hazard ratios (AHR). RESULTS Court appearances were associated with lower risk of subsequent speeding citations (AHR = 0.92; 95% CI: 0.88-0.96), but higher risk of crashes (AHR=1.25; 95% CI: 1.16-1.35). PBJ was associated with significantly lower repeat speeding tickets (AHR = 0.83; 95% CI = 0.75-0.91) and a non-significant decrease in crashes (AHR = 0.87; 95% CI 0.75-1.02). Both repeat speeding tickets and subsequent crashes were significantly lower in the STET/NP group. CONCLUSIONS PBJ and STET/NP may reduce speeding and crashes, but neither verdict eliminated excess crash risk among drivers who choose court appearances. Randomized controlled evaluations of speeding countermeasures are needed to inform traffic safety policies. PMID:21684176

  11. The effect of accuracy motivation on anchoring and adjustment: do people adjust from provided anchors?

    PubMed

    Simmons, Joseph P; LeBoeuf, Robyn A; Nelson, Leif D

    2010-12-01

    Increasing accuracy motivation (e.g., by providing monetary incentives for accuracy) often fails to increase adjustment away from provided anchors, a result that has led researchers to conclude that people do not effortfully adjust away from such anchors. We challenge this conclusion. First, we show that people are typically uncertain about which way to adjust from provided anchors and that this uncertainty often causes people to believe that they have initially adjusted too far away from such anchors (Studies 1a and 1b). Then, we show that although accuracy motivation fails to increase the gap between anchors and final estimates when people are uncertain about the direction of adjustment, accuracy motivation does increase anchor-estimate gaps when people are certain about the direction of adjustment, and that this is true regardless of whether the anchors are provided or self-generated (Studies 2, 3a, 3b, and 5). These results suggest that people do effortfully adjust away from provided anchors but that uncertainty about the direction of adjustment makes that adjustment harder to detect than previously assumed. This conclusion has important theoretical implications, suggesting that currently emphasized distinctions between anchor types (self-generated vs. provided) are not fundamental and that ostensibly competing theories of anchoring (selective accessibility and anchoring-and-adjustment) are complementary.

  12. Wind-powered asynchronous AC/DC/AC converter system. [for electric power supply regulation

    NASA Technical Reports Server (NTRS)

    Reitan, D. K.

    1973-01-01

    Two asynchronous ac/dc/ac systems are modelled that utilize wind power to drive a variable or constant hertz alternator. The first system employs a high power 60-hertz inverter tie to the large backup supply of the power company to either supplement them from wind energy, storage, or from a combination of both at a preset desired current; rectifier and inverter are identical and operate in either mode depending on the silicon control rectifier firing angle. The second system employs the same rectification but from a 60-hertz alternator arrangement; it provides mainly dc output, some sinusoidal 60-hertz from the wind bus and some high harmonic content 60-hertz from an 800-watt inverter.

  13. 24 CFR Appendices A-C to Subtitle A - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false A Appendices A-C to Subtitle A Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development Appendices A-C to Subtitle A...

  14. 24 CFR Appendixes A-C to Subtitle A - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false A Appendixes A-C to Subtitle A Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development Appendixes A-C to Subtitle A...

  15. 24 CFR Appendices A-C to Subtitle A - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false A Appendices A-C to Subtitle A Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development Appendices A-C to Subtitle A...

  16. 24 CFR Appendices A-C to Subtitle A - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false A Appendices A-C to Subtitle A Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development Appendices A-C to Subtitle A...

  17. 24 CFR Appendices A-C to Subtitle A - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false A Appendices A-C to Subtitle A Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development Appendices A-C to Subtitle A...

  18. 21 CFR 880.5500 - AC-powered patient lift.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5500 AC-powered patient lift. (a) Identification. An AC-powered lift is an electrically powered device either fixed or mobile, used to lift and transport patients in the horizontal or...

  19. Undergraduate Chemistry Education: Report of an ACS Presidential Symposium

    ERIC Educational Resources Information Center

    Polik, William F.

    2006-01-01

    The American Chemical Society (ACS) Presidential Symposium, Envisioning Undergraduate Chemistry Education in 2015 was organized by the ACS Committee on Professional Training (CPT), in response to the challenge to envision the chemistry enterprise in 2015. The need for more diverse role models at all levels is emphasized, including high school…

  20. 40 CFR Appendixes A-C to Part 403 - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 30 2013-07-01 2012-07-01 true A Appendixes A-C to Part 403 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GENERAL PRETREATMENT REGULATIONS FOR EXISTING AND NEW SOURCES OF POLLUTION Appendixes A-C to Part 403...