Sample records for vacuum circuit breakers

  1. Latest Trends of Vacuum Circuit Breaker and Related Technologies

    NASA Astrophysics Data System (ADS)

    Kozono, Hideaki; Tanimizu, Toru

    Vacuum Circuit Breakers (VCBs) have been widely used for medium voltage level, because of their performance: compact size, light weight, maintenance free operations and environment-friendly characteristics. They become most comfortable breakers for our needs from other breakers: oil, air, magnetic blast and gas. In this paper the history of vacuum, and latest trends of circuit breakers and related technologies are described, as well as merits or demerits of using vacuum technologies.

  2. Superconducting dc Current Limiting Vacuum Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Alferov, D. F.; Akhmetgareev, M. R.; Budovskii, A. I.; Bunin, R. A.; Voloshin, I. F.; Degtyarenko, P. N.; Yevsin, D. V.; Ivanov, V. P.; Sidorov, V. A.; Fisher, L. M.; Tshai, E. V.

    Acircuitofadc superconductingfault current limiter witha direct current circuit-breaker fora nominal current 300A is proposed. It includes the 2G high temperature superconducting (HTS) tapes and the high-speed dc vacuum circuit breaker.Thetestresultsof current-limitingcapacityandrecoverytimeof superconductivityafter currentfaultatvoltage upto3 kV are presented.

  3. The Influence of Vacuum Circuit Breakers and Different Motor Models on Switching Overvoltages in Motor Circuits

    NASA Astrophysics Data System (ADS)

    Wong, Cat S. M.; Snider, L. A.; Lo, Edward W. C.; Chung, T. S.

    Switching of induction motors with vacuum circuit breakers continues to be a concern. In this paper the influence on statistical overvoltages of the stochastic characteristics of vacuum circuit breakers, high frequency models of motors and transformers, and network characteristics, including cable lengths and network topology are evaluated and a general view of the overvoltages phenomena is presented. Finally, a real case study on the statistical voltage levels and risk-of-failure resulting from switching of a vacuum circuit breaker in an industrial installation in Hong Kong is presented.

  4. Present Status of Power Circuit Breaker and its Future

    NASA Astrophysics Data System (ADS)

    Yoshioka, Yoshio

    Gas circuit breaker and vacuum circuit breaker are the 2 main types of circuit breaker used in extra high voltage and medium voltage networks. After reviewing the history of these circuit breakers, their present status and technologies are described. As for future technology, computation of interrupting phenomena, SF6 gas less apparatus and expectation of the high voltage vacuum circuit breaker are discussed.

  5. An Electromagnetically Actuated Vacuum Circuit Breaker Developed by Electromagnetic Analysis Coupled with Motion

    NASA Astrophysics Data System (ADS)

    Takeuchi, Toshie; Nakagawa, Takafumi; Tsukima, Mitsuru; Koyama, Kenichi; Tohya, Nobumoto; Yano, Tomotaka

    A new electromagnetically actuated vacuum circuit breaker (VCB) has been designed and developed on the basis of the transient electromagnetic analysis coupled with motion. The VCB has three advanced bi-stable electromagnetic actuators, which control each phase independently. The VCB serves as a synchronous circuit breaker as well as a standard circuit breaker. In this work, the flux delay due to the eddy current is analytically formulated using the delay time constant of the actuator coil current, thereby leading to accurate driving behavior. With this analytical method, the electromagnetic mechanism for a 24kV rated VCB has been optimized; and as a result, the driving energy is reduced to one fifth of that of a conventional VCB employing spring mechanism, and the number of parts is significantly decreased. Therefore, the developed VCB becomes compact, highly reliable and highly durable.

  6. High temperature circuit breaker

    NASA Technical Reports Server (NTRS)

    Edwards, R. N.; Travis, E. F.

    1970-01-01

    Alternating current circuit breaker is suitable for reliable long-term service at 1000 deg F in the vacuum conditions of outer space. Construction materials are resistant to nuclear radiation and vacuum welding. Service test conditions and results are given.

  7. Review of 72.5kV double-break vacuum circuit breaker based on rapid repulsion actuator

    NASA Astrophysics Data System (ADS)

    Zhuofan, Tang; Lijun, Qin

    2017-07-01

    72.5kV double-break vacuum circuit breakers based on rapid repulsion actuator remain blank in China. Based on the theoretical analysis and experimental results from researchers, the design of 72.5kV double-break vacuum circuit breakers based on rapid repulsion actuator was presented. It takes the form of double-break, using two standard 40.5kV vacuum interrupter in series at the bottom, which adopt a permanent magnetic repulsion actuator. The permanent magnetic repulsion actuator consists of rapid repulsion actuator and magnetic retentivity actuator. On the basis above, we produced the prototype, and the superiority of the design was verified through the experiments.

  8. Development of High Interruption Capability Vacuum Circuit Breaker -Technology of Vacuum Arc Control-

    NASA Astrophysics Data System (ADS)

    Niwa, Yoshimitsu; Kaneko, Eiji

    Vacuum circuit breakers (VCB) have been widely used for power distribution systems. Vacuum Interrupters, which are the current interruption unit, have been increased its interruption capability with the development of vacuum arc control technology by magnetic field. There are three major type electrodes: disk shaped electrodes, radial magnetic field electrodes, axial magnetic field (AMF) electrodes. In the disk shaped electrode, the vacuum arc between the electrodes is not controlled. In the AMF electrode, the vacuum arc is diffused and stabilized by an axial magnetic field, which is parallel to the arc current. In the last type of electrodes, the vacuum arc column is rotated by magnetic force generated by the current flowing in the electrodes. The interruption current and the voltage of one break VCB is increased to 100 kA, 144 kV respectively. This paper describes basic configurations and functions of VCB, vacuum arc control technology in vacuum interrupters, recent researches and applications of VCB.

  9. DC Interruption Characteristic on Vacuum Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Odaka, Hiromi; Yamada, Masataka; Sakuma, Ryohei; Ding, Cuie; Kaneko, Eiji; Yanabu, Satoru

    A high speed vacuum circuit breaker (HSVCB) has been investigated. HSVCB makes high frequency current superimposed on a fault current so that the current is forced to be zero and is interrupted. Its interruption performance is considered to be dependent on a rate of change of the current (di/dt). As a fundamental research, we investigated the di/dt-dv/dt characteristics and the insulation recovery characteristic after interrupting the counter-pulse current for various contact materials of AgWC, CuW, and CuCr. The results revealed that the case where gap length is larger is better in a current interruption performance. Moreover, it was found that di/dt is not dependent on the insulation recovery characteristics, but the magnitude of interruption current influences greatly.

  10. Technical Trend of Environment-friendly High Voltage Vacuum Circuit Breaker (VCB)

    NASA Astrophysics Data System (ADS)

    Okubo, Hitoshi

    Vacuum Circuit Breakers (VCBs) have widely been used for low and medium voltage level, because of their high current interruption performance, maintenance free operations and environment-friendly characteristics. The VCB is now going to be applied to higher voltage systems for transmission and substation use. In this paper, the recent technical trend and future perspectives of high voltage VCBs are described, as well as their technical background.

  11. History of Circuit Breakers and Expectations of Japanese Original Development

    NASA Astrophysics Data System (ADS)

    Yoshioka, Yoshio; Yoshinaga, Kiyoshi; Yanabu, Satoru

    This paper studies the history of high voltage circuit breaker engineering. Methods of analysis are (1) to collect facts in regard to its development, (2) to review the history in order to find essential factors and (3) to identify its pros and cons from engineering point of view. The amount of electric power consumption has increased and gradually the circuit breaker concept was developed. At first the oil circuit breakers were developed in Europe and the air circuit breaker and vacuum circuit breaker were developed. Finally the SF6gas circuit breakers are developed together with the gas insulated switchgear and what is next? The future research and development policy is also discussed.

  12. Measuring technical and mathematical investigation of multiple reignitions at the switching of a motor using vacuum circuit breakers

    NASA Astrophysics Data System (ADS)

    Luxa, Andreas

    The necessary conditions in switching system and vacuum circuit breaker for the occurrence of multiple re-ignitions and accompanying effects were examined. The shape of the occurring voltages was determined in relationship to other types of overvoltage. A phenomenological model of the arc, based on an extension of the Mayr equation for arcs was used with the simulation program NETOMAC for the switching transients. Factors which affect the arc parameters were analyzed. The results were statistically verified by 3000 three-phase switching tests on 3 standard vacuum circuit breakers under realistic systems conditions; the occurring overvoltage level was measured. Dimensioning criteria for motor simulation circuits in power plants were formulated on the basis of a theoretical equivalence analysis and experimental studies. The simulation model allows a sufficiently correct estimation of all effects.

  13. Influence of the axial magnetic field on sheath development after current zero in a vacuum circuit breaker

    NASA Astrophysics Data System (ADS)

    Chen, Yi; Yang, Fei; Sun, Hao; Wu, Yi; Niu, Chunping; Rong, Mingzhe

    2017-06-01

    After current zero, which is the moment when the vacuum circuit breaker interrupts a vacuum arc, sheath development is the first process in the dielectric recovery process. An axial magnetic field (AMF) is widely used in the vacuum circuit breaker when the high-current vacuum arc is interrupted. Therefore, it is very important to study the influence of different AMF amplitudes on the sheath development. The objective of this paper is to study the influence of different AMF amplitudes on the sheath development from a micro perspective. Thus, the particle in cell-Monte Carlo collisions (PIC-MCC) method was adopted to develop the sheath development model. We compared the simulation results with the experimental results and then validated the simulation. We also obtained the speed of the sheath development and the energy density of the ions under different AMF amplitudes. The results showed that the larger the AMF amplitudes are, the faster the sheath develops and the lower the ion energy density is, meaning the breakdown is correspondingly more difficult.

  14. Development of a High-speed Electromagnetic Repulsion Mechanism for High-voltage Vacuum Circuit Breakers

    NASA Astrophysics Data System (ADS)

    Tsukima, Mitsuru; Takeuchi, Toshie; Koyama, Kenichi; Yoshiyasu, Hajimu

    This paper presents a design and testing of a new high-speed electromagnetic driving mechanism for a high-voltage vacuum circuit breaker (VCB). This mechanism is based on a high-speed electromagnetic repulsion and a permanent magnet spring (PMS). This PMS is introduced instead of the conventional disk spring due to its low spring energy and more suitable force characteristics for VCB application. The PMS has been optimally designed by the 3d non-linear finite-elements magnetic field analysis and investigated its internal friction and eddy-current effect. Furthermore, we calculated the dynamic of this mechanism coupling with the electromagnetic field and circuit analysis, in order to satisfy the operating characteristics—contact velocity, response time and so on, required for the high-speed VCB. A prototype VCB, which was built based on the above analysis shows sufficient operating performance. Finally, the short circuit interruption tests were carried out with this prototype breaker, and we have been able to verify its satisfying performance.

  15. Commutation circuit for an HVDC circuit breaker

    DOEpatents

    Premerlani, William J.

    1981-01-01

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components.

  16. Commutation circuit for an HVDC circuit breaker

    DOEpatents

    Premerlani, W.J.

    1981-11-10

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components. 13 figs.

  17. Digital model of a vacuum circuit breaker for the analysis of switching waveforms in electrical circuits

    NASA Astrophysics Data System (ADS)

    Budzisz, Joanna; Wróblewski, Zbigniew

    2016-03-01

    The article presents a method of modelling a vaccum circuit breaker in the ATP/EMTP package, the results of the verification of the correctness of the developed digital circuit breaker model operation and its practical usefulness for analysis of overvoltages and overcurrents occurring in commutated capacitive electrical circuits and also examples of digital simulations of overvoltages and overcurrents in selected electrical circuits.

  18. Development of 72kV High Pressure Air-insulated GIS with Vacuum Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Rokunohe, Toshiaki; Yagihashi, Yoshitaka; Endo, Fumihiro; Aoyagi, Kenji; Saitoh, Hitoshi; Oomori, Takashi

    SF6 gas has excellent dielectric strength and interruption performance. For these reasons, it has been widely used for gas insulated switchgear (GIS). However, use of SF6 gas has become regulated under agreements set at the 1997 COP3. So investigation and development for GIS with a lower amount of SF6 gas are being carried out worldwide. Presently, SF6 gas-free GIS has been commercialized for the 24kV class. Air or N2 gas is used as insulation gas for this GIS. On the other hand, SF6 gas-free GIS has not been commercialized for 72kV class GIS. Dielectric strengths of air and N2 gas are approximately 1/3 that of SF6 gas. So to enhance insulation performance of air and N2, we have investigated a hybrid gas insulation system which has the combined features of providing an insulation coating and suitable insulation gas. We have developed the world's first 72kV SF6 gas-free GIS. This paper deals with key technologies for SF6 gas-free GIS such as the hybrid insulation structure, bellows for the high pressure vacuum circuit breaker, a newly designed disconnector and spacer and prevention of particle levitation. Test results of 72kV high pressure air-insulated GIS with the vacuum circuit breaker are described.

  19. Sheath expansion and plasma dynamics in the presence of electrode evaporation: Application to a vacuum circuit breaker

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sarrailh, P.; LAPLACE, CNRS, F-31062 Toulouse; Schneider Electric, Centre de Recherche 38 TEC, 38050 Grenoble Cedex 09

    2009-09-01

    During the postarc dielectric recovery phase in a vacuum circuit breaker, a cathode sheath forms and expels the plasma from the electrode gap. The success or failure of current breaking depends on how efficiently the plasma is expelled from the electrode gap. The sheath expansion in the postarc phase can be compared to sheath expansion in plasma immersion ion implantation except that collisions between charged particles and atoms generated by electrode evaporation may become important in a vacuum circuit breaker. In this paper, we show that electrode evaporation plays a significant role in the dynamics of the sheath expansion inmore » this context not only because charged particle transport is no longer collisionless but also because the neutral flow due to evaporation and temperature gradients may push the plasma toward one of the electrodes. Using a hybrid model of the nonequilibrium postarc plasma and cathode sheath coupled with a direct simulation Monte Carlo method to describe collisions between heavy species, we present a parametric study of the sheath and plasma dynamics and of the time needed for the sheath to expel the plasma from the gap for different values of plasma density and electrode temperatures at the beginning of the postarc phase. This work constitutes a preliminary step toward understanding and quantifying the risk of current breaking failure of a vacuum arc.« less

  20. Sheath expansion and plasma dynamics in the presence of electrode evaporation: Application to a vacuum circuit breaker

    NASA Astrophysics Data System (ADS)

    Sarrailh, P.; Garrigues, L.; Hagelaar, G. J. M.; Boeuf, J. P.; Sandolache, G.; Rowe, S.

    2009-09-01

    During the postarc dielectric recovery phase in a vacuum circuit breaker, a cathode sheath forms and expels the plasma from the electrode gap. The success or failure of current breaking depends on how efficiently the plasma is expelled from the electrode gap. The sheath expansion in the postarc phase can be compared to sheath expansion in plasma immersion ion implantation except that collisions between charged particles and atoms generated by electrode evaporation may become important in a vacuum circuit breaker. In this paper, we show that electrode evaporation plays a significant role in the dynamics of the sheath expansion in this context not only because charged particle transport is no longer collisionless but also because the neutral flow due to evaporation and temperature gradients may push the plasma toward one of the electrodes. Using a hybrid model of the nonequilibrium postarc plasma and cathode sheath coupled with a direct simulation Monte Carlo method to describe collisions between heavy species, we present a parametric study of the sheath and plasma dynamics and of the time needed for the sheath to expel the plasma from the gap for different values of plasma density and electrode temperatures at the beginning of the postarc phase. This work constitutes a preliminary step toward understanding and quantifying the risk of current breaking failure of a vacuum arc.

  1. 46 CFR 169.670 - Circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Gross Tons § 169.670 Circuit breakers. Each circuit breaker must be of the manually reset type designed for— (a) Inverse time delay; (b) Instantaneous short circuit protection; and (c) Repeated opening of... 46 Shipping 7 2010-10-01 2010-10-01 false Circuit breakers. 169.670 Section 169.670 Shipping COAST...

  2. Post-arc current simulation based on measurement in vacuum circuit breaker with a one-dimensional particle-in-cell model

    NASA Astrophysics Data System (ADS)

    Jia, Shenli; Mo, Yongpeng; Shi, Zongqian; Li, Junliang; Wang, Lijun

    2017-10-01

    The post-arc dielectric recovery process has a decisive effect on the current interruption performance in a vacuum circuit breaker. The dissipation of residual plasma at the moment of current zero under the transient recovery voltage, which is the first stage of the post-arc dielectric recovery process and forms the post-arc current, has attracted many concerns. A one-dimensional particle-in-cell model is developed to simulate the measured post-arc current in the vacuum circuit breaker in this paper. At first, the parameters of the residual plasma are estimated roughly by the waveform of the post-arc current which is taken from measurements. After that, different components of the post-arc current, which are formed by the movement of charged particles in the residual plasma, are discussed. Then, the residual plasma density is adjusted according to the proportion of electrons and ions absorbed by the post-arc anode derived from the particle-in-cell simulation. After this adjustment, the post-arc current waveform obtained from the simulation is closer to that obtained from measurements.

  3. A New Method for Raising Opening Velocity of Electromagnetic Actuated Vacuum Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Tsukima, Mitsuru; Takeuchi, Toshie; Koyama, Kenichi; Yoshiyasu, Hajimu

    Recently an electromagnetic actuator has been widely used as an operating mechanism for the vacuum circuit breaker (VCB). The opening velocity of the contact is supposed to be strongly related with current interruption performance. This paper presents a simple and new technique that raises opening velocity of the electromagnetic actuated VCB. In order to investigate this reason, we built a numerical simulator that predicts the dynamic characteristics of the VCB contact. It takes into account of the magnetic behavior in the actuator and is also coupled with the external control circuit. According to this simulation, it is shown that it is originated from the sharp rise in the electromagnetic thrust force due to the selective saturation of the magnetic yoke. As the result of our experiments, by this technique the opening velocity was verified to be 1.5 times faster than by the conventional way.

  4. 30 CFR 75.800 - High-voltage circuits; circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... shall be equipped with devices to provide protection against under-voltage grounded phase, short circuit... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 75.800... § 75.800 High-voltage circuits; circuit breakers. [Statutory Provisions] High-voltage circuits entering...

  5. Electric circuit breaker comprising a plurality of vacuum interrupters simultaneously operated by a common operator

    DOEpatents

    Barkan, Philip; Imam, Imdad

    1980-01-01

    This circuit breaker comprises a plurality of a vacuum-type circuit interrupters, each having a movable contact rod. A common operating device for the interrupters comprises a linearly-movable operating member. The interrupters are mounted at one side of the operating member with their movable contact rods extending in a direction generally toward the operating member. Means is provided for mechanically coupling the operating member to the contact rods, and this means comprises a plurality of insulating operating rods, each connected at one end to the operating member and at its opposite end to one of the movable contact rods. The operating rods are of substantially equal length and have longitudinal axes that converge and intersect at substantially a common point.

  6. 30 CFR 77.800 - High-voltage circuits; circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... devices to provide protection against under voltage, grounded phase, short circuit and overcurrent. High... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 77.800... COAL MINES Surface High-Voltage Distribution § 77.800 High-voltage circuits; circuit breakers. High...

  7. High Speed Solid State Circuit Breaker

    NASA Technical Reports Server (NTRS)

    Podlesak, Thomas F.

    1993-01-01

    The U.S. Army Research Laboratory, Fort Monmouth, NJ, has developed and is installing two 3.3 MW high speed solid state circuit breakers at the Army's Pulse Power Center. These circuit breakers will interrupt 4160V three phase power mains in no more than 300 microseconds, two orders of magnitude faster than conventional mechanical contact type circuit breakers. These circuit breakers utilize Gate Turnoff Thyristors (GTO's) and are currently utility type devices using air cooling in an air conditioned enclosure. Future refinements include liquid cooling, either water or two phase organic coolant, and more advanced semiconductors. Each of these refinements promises a more compact, more reliable unit.

  8. Influence of residual plasma drift velocity on the post-arc sheath expansion of vacuum circuit breakers

    NASA Astrophysics Data System (ADS)

    Mo, Yongpeng; Shi, Zongqian; Bai, Zhibin; Jia, Shenli; Wang, Lijun

    2016-05-01

    The residual plasma in the inter-contact region of a vacuum circuit breaker moves towards the post-arc cathode at current zero, because the residual plasma mainly comes from the cathode spots during the arc burning process. In the most previous theoretical researches on the post-arc sheath expansion process of vacuum circuit breakers, only the thermal motion of residual plasma was taken into consideration. Alternately, the residual plasma was even assumed to be static at the moment of current zero in some simplified models. However, the influence of residual plasma drift velocity at current zero on the post-arc sheath expansion process was rarely investigated. In this paper, this effect is investigated by a one-dimensional particle-in-cell model. Simulation results indicate that the sheath expands slower with higher residual plasma drift velocity in the initial sheath expansion stage. However, with the increase of residual plasma drift velocity, the overall plasma density in the inter-contact region decreases faster, and the sheath expansion velocity increases earlier. Consequently, as a whole, it needs shorter time to expel the residual plasma from the inter-contact region. Furthermore, if the residual plasma drift velocity is high enough, the sheath expansion process ceases before it develops to the post-arc anode. Besides, the influence of the collisions between charges and neutrals is investigated as well in terms of the density of metal vapor. It shows that the residual plasma drift velocity takes remarkable effect only if the density of the metal vapor is relatively low, which corresponds to the circumstance of low-current interruptions.

  9. Development of Electromagnetically Actuated Vacuum Circuit Breaker for 72kV Rated Switchgear

    NASA Astrophysics Data System (ADS)

    Kim, Tae-Hyun; Tsukima, Mitsuru; Maruyama, Akihiko; Takahara, Osamu; Haruna, Kazushi; Yano, Tomotaka; Matsunaga, Toshihiro; Imamura, Kazuaki; Arioka, Masahiro; Takeuchi, Toshie

    A new electromagnetically actuated vacuum circuit breaker (VCB) has been developed for a 72kV rated switchgear. Each phase of this VCB has a plurality of compact electromagnetic actuators linked mechanically providing the required driving energy. The mechanical linkage working as a lever magnifies an actuator stroke to the required stroke of a 72kV rated vacuum interrupter. An electromagnetic analysis coupled with motion, which considers the mechanical linkage of the plural actuators, has been developed for designing the driving behavior of this VCB. Using this analytical method and a quality engineering method known as the Taguchi method, we have clarified effective parameters to reduce the time difference of the driving behavior for tolerance specifications. Moreover, analyzing the oscillatory behavior closing the contacts, a structure of this VCB has been designed to reduce the bounce duration. The developed new VCB has been confirmed that a time difference is short enough and bounce duration is reduced. This VCB is highly reliable against variations in manufacturing and environment.

  10. 30 CFR 75.800-1 - Circuit breakers; location.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit breakers; location. 75.800-1 Section 75.800-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... § 75.800-1 Circuit breakers; location. Circuit breakers protecting high-voltage circuits entering an...

  11. 30 CFR 75.900-1 - Circuit breakers; location.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit breakers; location. 75.900-1 Section 75.900-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... Alternating Current Circuits § 75.900-1 Circuit breakers; location. Circuit breakers used to protect low-and...

  12. Circuit breaker lockout device

    DOEpatents

    Kozlowski, Lawrence J.; Shirey, Lawrence A.

    1992-01-01

    An improved lockout assembly for locking a circuit breaker in a selected off or on position is provided. The lockout assembly includes a lock block and a lock pin. The lock block has a hollow interior which fits over the free end of a switch handle of the circuit breaker. The lock block includes at least one hole that is placed in registration with a hole in the free end of the switch handle. A lock tab on the lock block serves to align and register the respective holes on the lock block and switch handle. A lock pin is inserted through the registered holes and serves to connect the lock block to the switch handle. Once the lock block and the switch handle are connected, the position of the switch handle is prevented from being changed by the lock tab bumping up against a stationary housing portion of the circuit breaker. When the lock pin installed, an apertured-end portion of the lock pin is in registration with another hole on the lock block. Then a special scissors conforming to O.S.H.A. regulations can be installed, with one or more padlocks, on the lockout assembly to prevent removal of the lock pin from the lockout assembly, thereby preventing removal of the lockout assembly from the circuit breaker.

  13. Circuit breaker lockout device

    DOEpatents

    Kozlowski, L.J.; Shirey, L.A.

    1992-11-24

    An improved lockout assembly for locking a circuit breaker in a selected off or on position is provided. The lockout assembly includes a lock block and a lock pin. The lock block has a hollow interior which fits over the free end of a switch handle of the circuit breaker. The lock block includes at least one hole that is placed in registration with a hole in the free end of the switch handle. A lock tab on the lock block serves to align and register the respective holes on the lock block and switch handle. A lock pin is inserted through the registered holes and serves to connect the lock block to the switch handle. Once the lock block and the switch handle are connected, the position of the switch handle is prevented from being changed by the lock tab bumping up against a stationary housing portion of the circuit breaker. When the lock pin installed, an apertured-end portion of the lock pin is in registration with another hole on the lock block. Then a special scissors conforming to O.S.H.A. regulations can be installed, with one or more padlocks, on the lockout assembly to prevent removal of the lock pin from the lockout assembly, thereby preventing removal of the lockout assembly from the circuit breaker. 2 figs.

  14. Influence of residual plasma drift velocity on the post-arc sheath expansion of vacuum circuit breakers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mo, Yongpeng; Shi, Zongqian; Jia, Shenli

    The residual plasma in the inter-contact region of a vacuum circuit breaker moves towards the post-arc cathode at current zero, because the residual plasma mainly comes from the cathode spots during the arc burning process. In the most previous theoretical researches on the post-arc sheath expansion process of vacuum circuit breakers, only the thermal motion of residual plasma was taken into consideration. Alternately, the residual plasma was even assumed to be static at the moment of current zero in some simplified models. However, the influence of residual plasma drift velocity at current zero on the post-arc sheath expansion process wasmore » rarely investigated. In this paper, this effect is investigated by a one-dimensional particle-in-cell model. Simulation results indicate that the sheath expands slower with higher residual plasma drift velocity in the initial sheath expansion stage. However, with the increase of residual plasma drift velocity, the overall plasma density in the inter-contact region decreases faster, and the sheath expansion velocity increases earlier. Consequently, as a whole, it needs shorter time to expel the residual plasma from the inter-contact region. Furthermore, if the residual plasma drift velocity is high enough, the sheath expansion process ceases before it develops to the post-arc anode. Besides, the influence of the collisions between charges and neutrals is investigated as well in terms of the density of metal vapor. It shows that the residual plasma drift velocity takes remarkable effect only if the density of the metal vapor is relatively low, which corresponds to the circumstance of low-current interruptions.« less

  15. Low Insertion HVDC Circuit Breaker: Magnetically Pulsed Hybrid Breaker for HVDC Power Distribution Protection

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    2012-01-09

    GENI Project: General Atomics is developing a direct current (DC) circuit breaker that could protect the grid from faults 100 times faster than its alternating current (AC) counterparts. Circuit breakers are critical elements in any electrical system. At the grid level, their main function is to isolate parts of the grid where a fault has occurred—such as a downed power line or a transformer explosion—from the rest of the system. DC circuit breakers must interrupt the system during a fault much faster than AC circuit breakers to prevent possible damage to cables, converters and other grid-level components. General Atomics’ high-voltagemore » DC circuit breaker would react in less than 1/1,000th of a second to interrupt current during a fault, preventing potential hazards to people and equipment.« less

  16. Modeling of breakdown during the post-arc phase of a vacuum circuit breaker

    NASA Astrophysics Data System (ADS)

    Sarrailh, P.; Garrigues, L.; Boeuf, J. P.; Hagelaar, G. J. M.

    2010-12-01

    After a high-current interruption in a vacuum circuit breaker (VCB), the electrode gap is filled with a high density copper vapor plasma in a large copper vapor density (~1022 m-3). The copper vapor density is sustained by electrode evaporation. During the post-arc phase, a rapidly increasing voltage is applied to the gap, and a sheath forms and expands, expelling the plasma from the gap when circuit breaking is successful. There is, however, a risk of breakdown during that phase, leading to the failure of the VCB. Preventing breakdown during the post-arc phase is an important issue for the improvement of VCB reliability. In this paper, we analyze the risk of Townsend breakdown in the high copper vapor density during the post-arc phase using a numerical model that takes into account secondary electron emission, volume ionization, and plasma and neutral transport, for given electrode temperatures. The simulations show that fast neutrals created in the cathode sheath by charge exchange collisions with ions generate a very large secondary electron emission current that can lead to Townsend breakdown. The results also show that the risk of failure of the VCB due to Townsend breakdown strongly depends on the electrode temperatures (which govern the copper vapor density) and becomes important for temperatures greater than 2100 K, which can be reached in vacuum arcs. The simulations also predict that a hotter anode tends to increase the risk of Townsend breakdown.

  17. Hydraulic actuator for an electric circuit breaker

    DOEpatents

    Imam, I.

    1983-05-17

    This actuator comprises a fluid motor having a piston, a breaker-opening space at one side of the piston, and a breaker-closing space at its opposite side. An accumulator freely communicates with the breaker-opening space for supplying pressurized fluid thereto during a circuit breaker opening operation. The breaker-opening space and the breaker-closing space are connected by an impeded flow passage. A pilot valve opens to allow the pressurized liquid in the breaker-closing space to flow to a back chamber of a normally closed main valve to cause the main valve to be opened during a circuit breaker opening operation to release the pressurized liquid from the breaker-closing space. An impeded passage affords communication between the back chamber and a sump located on the opposite side of the main valve from the back chamber. The pilot valve and impeded passage allow rapid opening of the main valve with pressurized liquid from the breaker closing side of the piston. 3 figs.

  18. Hydraulic actuator for an electric circuit breaker

    DOEpatents

    Imam, Imdad [Colonie, NY

    1983-01-01

    This actuator comprises a fluid motor having a piston, a breaker-opening space at one side of the piston, and a breaker-closing space at its opposite side. An accumulator freely communicates with the breaker-opening space for supplying pressurized fluid thereto during a circuit breaker opening operation. The breaker-opening space and the breaker-closing space are connected by an impeded flow passage. A pilot valve opens to allow the pressurized liquid in the breaker-closing space to flow to a back chamber of a normally closed main valve to cause the main valve to be opened during a circuit breaker opening operation to release the pressurized liquid from the breaker-closing space. An impeded passage affords communication between the back chamber and a sump located on the opposite side of the main valve from the back chamber. The pilot valve and impeded passage allow rapid opening of the main valve with pressurized liquid from the breaker closing side of the piston.

  19. Development of the Vacuum Circuit Breaker with an Electromagnetic Actuator

    NASA Astrophysics Data System (ADS)

    Morita, Ayumu; Yabu, Masato; Kajiwara, Satoru

    A new type of vacuum circuit breaker (VCB) has been developed, which needs a minimum of maintenance. This VCB is characterized by the following: (a) a significantly simplified driving mechanism, (b) no need for grease, and (c) a new electromagnetic actuator called a hybrid-type electromagnet. The number of movable parts is decreased to 15% of that of our conventional product with a spring drive. Solid lubricant is adopted instead of grease for almost all of the linkages, which helps to eliminate periodical lubricating maintenance. The hybrid-type electromagnet has an attractive force suitable for the spring force characteristics of the VCB through its combination of conventional plunger-type and plate-armature-type electromagnet. The VCB is held in the closed position by the attractive force of the permanent magnet without using a coil current. Its core structure is optimized to prevent the permanent magnet from demagnetization and to secure long-term reliability. To assess the solid lubricant reliability, some special tests were performed such as a rare operation test. Dynamic characteristics were measured for three specimens at intervals of a month, a year, and two years, respectively. It was confirmed that variation of the armature speed is small and the influence of the non-operation interval is negligible.

  20. Development, Integration and Testing of Automated Triggering Circuit for Hybrid DC Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Kanabar, Deven; Roy, Swati; Dodiya, Chiragkumar; Pradhan, Subrata

    2017-04-01

    A novel concept of Hybrid DC circuit breaker having combination of mechanical switch and static switch provides arc-less current commutation into the dump resistor during quench in superconducting magnet operation. The triggering of mechanical and static switches in Hybrid DC breaker can be automatized which can effectively reduce the overall current commutation time of hybrid DC circuit breaker and make the operation independent of opening time of mechanical switch. With this view, a dedicated control circuit (auto-triggering circuit) has been developed which can decide the timing and pulse duration for mechanical switch as well as static switch from the operating parameters. This circuit has been tested with dummy parameters and thereafter integrated with the actual test set up of hybrid DC circuit breaker. This paper deals with the conceptual design of the auto-triggering circuit, its control logic and operation. The test results of Hybrid DC circuit breaker using this circuit have also been discussed.

  1. Circuit breaker lock out assembly

    DOEpatents

    Gordy, W.T.

    1983-05-18

    A lock out assembly for a circuit breaker which consists of a generally step-shaped unitary base with an aperture in the small portion of the step-shaped base and a roughly S shaped retaining pin which loops through the large portion of the step-shaped base. The lock out assembly is adapted to fit over a circuit breaker with the handle switch projecting through the aperture, and the retaining pin projecting into an opening of the handle switch, preventing removal.

  2. Circuit breaker lock out assembly

    DOEpatents

    Gordy, Wade T.

    1984-01-01

    A lock out assembly for a circuit breaker which consists of a generally step-shaped unitary base with an aperture in the small portion of the step-shaped base and a roughly "S" shaped retaining pin which loops through the large portion of the step-shaped base. The lock out assembly is adapted to fit over a circuit breaker with the handle switch projecting through the aperture, and the retaining pin projecting into an opening of the handle switch, preventing removal.

  3. Lockout device for high voltage circuit breaker

    DOEpatents

    Kozlowski, Lawrence J.; Shirey, Lawrence A.

    1993-01-01

    An improved lockout assembly is provided for a circuit breaker to lock the switch handle into a selected switch position. The lockout assembly includes two main elements, each having a respective foot for engaging a portion of the upper housing wall of the circuit breaker. The first foot is inserted into a groove in the upper housing wall, and the second foot is inserted into an adjacent aperture (e.g., a slot) in the upper housing wall. The first foot is slid under and into engagement with a first portion, and the second foot is slid under and into engagement with a second portion of the upper housing wall. At the same time the repsective two feet are placed in engagement with the respective portions of the upper housing wall, two holes, one on each of the respective two main elements of the assembly, are placed in registration; and a locking device, such as a special scissors equipped with a padlock, is installed through the registered holes to secure the lockout assembly on the circuit breaker. When the lockout assembly of the invention is secured on the circuit breaker, the switch handle of the circuit breaker is locked into the selected switch position and prevented from being switched to another switch position.

  4. Lockout device for high voltage circuit breaker

    DOEpatents

    Kozlowski, L.J.; Shirey, L.A.

    1993-01-26

    An improved lockout assembly is provided for a circuit breaker to lock the switch handle into a selected switch position. The lockout assembly includes two main elements, each having a respective foot for engaging a portion of the upper housing wall of the circuit breaker. The first foot is inserted into a groove in the upper housing wall, and the second foot is inserted into an adjacent aperture (e.g., a slot) in the upper housing wall. The first foot is slid under and into engagement with a first portion, and the second foot is slid under and into engagement with a second portion of the upper housing wall. At the same time the respective two feet are placed in engagement with the respective portions of the upper housing wall, two holes, one on each of the respective two main elements of the assembly, are placed in registration; and a locking device, such as a special scissors equipped with a padlock, is installed through the registered holes to secure the lockout assembly on the circuit breaker. When the lockout assembly of the invention is secured on the circuit breaker, the switch handle of the circuit breaker is locked into the selected switch position and prevented from being switched to another switch position.

  5. 30 CFR 75.601-1 - Short circuit protection; ratings and settings of circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Trailing Cables § 75.601-1 Short circuit protection; ratings and settings of circuit breakers. Circuit breakers providing short circuit protection for trailing cables shall be set so as not to exceed the...

  6. 30 CFR 77.809 - Identification of circuit breakers and disconnecting switches.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Identification of circuit breakers and disconnecting switches. 77.809 Section 77.809 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... circuit breakers and disconnecting switches. Circuit breakers and disconnecting switches shall be labeled...

  7. 30 CFR 77.809 - Identification of circuit breakers and disconnecting switches.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Identification of circuit breakers and disconnecting switches. 77.809 Section 77.809 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... circuit breakers and disconnecting switches. Circuit breakers and disconnecting switches shall be labeled...

  8. 30 CFR 77.809 - Identification of circuit breakers and disconnecting switches.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Identification of circuit breakers and disconnecting switches. 77.809 Section 77.809 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... circuit breakers and disconnecting switches. Circuit breakers and disconnecting switches shall be labeled...

  9. 30 CFR 77.809 - Identification of circuit breakers and disconnecting switches.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Identification of circuit breakers and disconnecting switches. 77.809 Section 77.809 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... circuit breakers and disconnecting switches. Circuit breakers and disconnecting switches shall be labeled...

  10. 30 CFR 77.809 - Identification of circuit breakers and disconnecting switches.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Identification of circuit breakers and disconnecting switches. 77.809 Section 77.809 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... circuit breakers and disconnecting switches. Circuit breakers and disconnecting switches shall be labeled...

  11. An Overview of Dynamic Contact Resistance Measurement of HV Circuit Breakers

    NASA Astrophysics Data System (ADS)

    Bhole, A. A.; Gandhare, W. Z.

    2016-06-01

    With the deregulation of the electrical power industry, utilities and service companies are operating in a changing business environment. High voltage circuit breakers are extremely important for the function of modern electric power supply systems. The need to predict the proper function of circuit breaker grew over the years as the transmission networks expanded. The maintenance of circuit breakers deserves special consideration because of their importance for routine switching and for protection of other equipments. Electric transmission system breakups and equipment destruction can occur if a circuit breaker fails to operate because of a lack of preventive maintenance. Dynamic Contact Resistance Measurement (DCRM) is known as an effective technique for assessing the condition of power circuit breakers contacts and operating mechanism. This paper gives a general review about DCRM. It discusses the practical case studies on use of DCRM for condition assessment of high voltage circuit breakers.

  12. Programmable Low-Voltage Circuit Breaker and Tester

    NASA Technical Reports Server (NTRS)

    Greenfield, Terry

    2008-01-01

    An instrumentation system that would comprise a remotely controllable and programmable low-voltage circuit breaker plus several electric-circuit-testing subsystems has been conceived, originally for use aboard a spacecraft during all phases of operation from pre-launch testing through launch, ascent, orbit, descent, and landing. The system could also be adapted to similar use aboard aircraft. In comparison with remotely controllable circuit breakers heretofore commercially available, this system would be smaller, less massive, and capable of performing more functions, as needed for aerospace applications.

  13. Hydraulically-activated operating system for an electric circuit breaker

    DOEpatents

    Imam, Imdad; Barkan, Philip

    1979-01-01

    This operating system comprises a fluid motor having a piston, a breaker-opening space at one side of the piston, and a breaker-closing space at its opposite side. An accumulator freely communicates with the breaker-opening space for supplying pressurized fluid thereto during a circuit-breaker opening operation. A normally-closed valve located on the breaker-closing-side of the piston is openable to release liquid from the breaker-closing space so that pressurized liquid in the breaker-opening space can drive the piston in an opening direction. Means is provided for restoring the valve to its closed position following the circuit-breaker opening operation. An impeded passage affords communication between the accumulator and the breaker-closing space to allow pressurized liquid to flow from the accumulator to the breaker-closing space and develop a pressure therein substantially equal to accumulator pressure when the valve is restored to closed position following breaker-opening. This passage is so impeded that the flow therethrough from the accumulator into the breaker-closing space is sufficiently low during initial opening motion of the piston through a substantial portion of its opening stroke as to avoid interference with said initial opening motion of the piston.

  14. 46 CFR 111.54-1 - Circuit breakers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Circuit breakers. 111.54-1 Section 111.54-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL... breaker must not: (1) Be dependent upon mechanical cooling to operate within its rating; or (2) Have a...

  15. 46 CFR 111.54-1 - Circuit breakers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Circuit breakers. 111.54-1 Section 111.54-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL... breaker must not: (1) Be dependent upon mechanical cooling to operate within its rating; or (2) Have a...

  16. 46 CFR 111.54-1 - Circuit breakers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Circuit breakers. 111.54-1 Section 111.54-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL... breaker must not: (1) Be dependent upon mechanical cooling to operate within its rating; or (2) Have a...

  17. 46 CFR 111.54-1 - Circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Circuit breakers. 111.54-1 Section 111.54-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL... breaker must not: (1) Be dependent upon mechanical cooling to operate within its rating; or (2) Have a...

  18. 30 CFR 77.800-1 - Testing, examination, and maintenance of circuit breakers; procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., examination, and maintenance of circuit breakers; procedures. (a) Circuit breakers and their auxiliary devices protecting high-voltage circuits to portable or mobile equipment shall be tested and examined at least once... circuit breaker and its auxiliary devices, and such repairs or adjustments as are indicated by such tests...

  19. Numerical modeling of high-voltage circuit breaker arcs and their interraction with the power system

    NASA Astrophysics Data System (ADS)

    Orama, Lionel R.

    In this work the interaction between series connected gas and vacuum circuit breaker arcs has been studied. The breakdown phenomena in vacuum interrupters during the post arc current period have been of special interest. Numerical models of gas and vacuum arcs were developed in the form of black box models. Especially, the vacuum post arc model was implemented by combining the existing transition model with an ion density function and expressions for the breakdown mechanisms. The test series studied reflect that for electric fields on the order of 10sp7V/m over the anode, the breakdown of the vacuum gap can result from a combination of both thermal and electrical stresses. For a particular vacuum device, the vacuum model helps to find the interruption limits of the electric field and power density over the anode. The series connection of gas and vacuum interrupters always performs better than the single gas device. Moreover, to take advantage of the good characteristics of both devices, the time between the current zero crossing in each interrupter can be changed. This current zero synchronization is controlled by changing the capacitance in parallel to the gas device. This gas/vacuum interrupter is suitable for interruption of very stressful short circuits in which the product of the dI/dt before current zero and the dV/dt after current zero is very high. Also, a single SF6 interrupter can be replaced by an air circuit breaker of the same voltage rating in series with a vacuum device without compromising the good performance of the SF6 device. Conceptually, a series connected vacuum device can be used for high voltage applications with equal distribution of electrical stresses between the individual interrupters. The equalization can be made by a sequential opening of the individual contact pairs, beginning with the interruptors that are closer to ground potential. This could eliminate the use of grading capacitors.

  20. Direct current hybrid breakers: A design and its realization

    NASA Astrophysics Data System (ADS)

    Atmadji, Ali Mahfudz Surya

    2000-12-01

    The use of semiconductors for electric power circuit breakers instead of conventional breakers remains a utopia when designing fault current interrupters for high power networks. The major problems concerning power semiconductor circuit breakers are the excessive heat losses and their sensitivity to transients. However, conventional breakers are capable of dealing with such matters. A combination of the two methods, or so-called `hybrid breakers', would appear to be a solution; however, hybrid breakers use separate parallel branches for conducting the main current and interrupting the short-circuit current. Such breakers are intended for protecting direct current (DC) traction systems. In this thesis hybrid switching techniques for current limitation and purely solidstate current interruption are investigated for DC breakers. This work analyzes the transient behavior of hybrid breakers and compares their operations with conventional breakers and similar solid-state devices in DC systems. Therefore a hybrid breaker was constructed and tested in a specially designed high power test circuit. A vacuum breaker was chosen as the main breaker in the main conducting path; then a commutation path was connected across the vacuum breaker where it provided current limitation and interruption. The commutation path operated only during any current interruption and the process required additional circuits. These included a certain energy storage, overvoltage suppressor and commutation switch. So that when discharging this energy, a controlled counter-current injection could be produced. That counter-current opposed the main current in the breaker by superposition in order to create a forced current-zero. One-stage and two-stage commutation circuits have been treated extensively. This study project contains both theoretical and experimental investigations. A direct current shortcircuit source was constructed capable of delivering power equivalent to a fault. It supplied a direct

  1. Biocompatible circuit-breaker chip for thermal management of biomedical microsystems

    NASA Astrophysics Data System (ADS)

    Luo, Yi; Dahmardeh, Masoud; Takahata, Kenichi

    2015-05-01

    This paper presents a thermoresponsive micro circuit breaker for biomedical applications specifically targeted at electronic intelligent implants. The circuit breaker is micromachined to have a shape-memory-alloy cantilever actuator as a normally closed temperature-sensitive switch to protect the device of interest from overheating, a critical safety feature for smart implants including those that are electrothermally driven with wireless micro heaters. The device is fabricated in a size of 1.5  ×  2.0  ×  0.46 mm3 using biocompatible materials and a chip-based titanium package, exhibiting a nominal cold-state resistance of 14 Ω. The breaker rapidly enters the full open condition when the chip temperature exceeds 63 °C, temporarily breaking the circuit of interest to lower its temperature until chip temperature drops to 51 °C, at which the breaker closes the circuit to allow current to flow through it again, physically limiting the maximum temperature of the circuit. This functionality is tested in combination with a wireless resonant heater powered by radio-frequency electromagnetic radiation, demonstrating self-regulation of heater temperature. The developed circuit-breaker chip operates in a fully passive manner that removes the need for active sensor and circuitry to achieve temperature regulation in a target device, contributing to the miniaturization of biomedical microsystems including electronic smart implants where thermal management is essential.

  2. 30 CFR 75.800-3 - Testing, examination and maintenance of circuit breakers; procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... High-Voltage Distribution § 75.800-3 Testing, examination and maintenance of circuit breakers; procedures. (a) Circuit breakers and their auxiliary devices protecting underground high-voltage circuits...

  3. 30 CFR 75.809 - Identification of circuit breakers and disconnecting switches.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... disconnecting switches. 75.809 Section 75.809 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... High-Voltage Distribution § 75.809 Identification of circuit breakers and disconnecting switches. [Statutory Provisions] Circuit breakers and disconnecting switches underground shall be marked for...

  4. 30 CFR 75.809 - Identification of circuit breakers and disconnecting switches.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... disconnecting switches. 75.809 Section 75.809 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... High-Voltage Distribution § 75.809 Identification of circuit breakers and disconnecting switches. [Statutory Provisions] Circuit breakers and disconnecting switches underground shall be marked for...

  5. 30 CFR 75.809 - Identification of circuit breakers and disconnecting switches.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... disconnecting switches. 75.809 Section 75.809 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... High-Voltage Distribution § 75.809 Identification of circuit breakers and disconnecting switches. [Statutory Provisions] Circuit breakers and disconnecting switches underground shall be marked for...

  6. 30 CFR 75.809 - Identification of circuit breakers and disconnecting switches.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... disconnecting switches. 75.809 Section 75.809 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... High-Voltage Distribution § 75.809 Identification of circuit breakers and disconnecting switches. [Statutory Provisions] Circuit breakers and disconnecting switches underground shall be marked for...

  7. 30 CFR 75.809 - Identification of circuit breakers and disconnecting switches.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... disconnecting switches. 75.809 Section 75.809 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... High-Voltage Distribution § 75.809 Identification of circuit breakers and disconnecting switches. [Statutory Provisions] Circuit breakers and disconnecting switches underground shall be marked for...

  8. Automatic recloser circuit breaker integrated with GSM technology for power system notification

    NASA Astrophysics Data System (ADS)

    Lada, M. Y.; Khiar, M. S. A.; Ghani, S. A.; Nawawi, M. R. M.; Rahim, N. H.; Sinar, L. O. M.

    2015-05-01

    Lightning is one type of transient faults that usually cause the circuit breaker in the distribution board trip due to overload current detection. The instant tripping condition in the circuit breakers clears the fault in the system. Unfortunately most circuit breakers system is manually operated. The power line will be effectively re-energized after the clearing fault process is finished. Auto-reclose circuit is used on the transmission line to carry out the duty of supplying quality electrical power to customers. In this project, an automatic reclose circuit breaker for low voltage usage is designed. The product description is the Auto Reclose Circuit Breaker (ARCB) will trip if the current sensor detects high current which exceeds the rated current for the miniature circuit breaker (MCB) used. Then the fault condition will be cleared automatically and return the power line to normal condition. The Global System for Mobile Communication (GSM) system will send SMS to the person in charge if the tripping occurs. If the over current occurs in three times, the system will fully trip (open circuit) and at the same time will send an SMS to the person in charge. In this project a 1 A is set as the rated current and any current exceeding a 1 A will cause the system to trip or interrupted. This system also provides an additional notification for user such as the emergency light and warning system.

  9. 100-kA vacuum current breaker of a modular design

    NASA Astrophysics Data System (ADS)

    Ivanov, V. P.; Vozdvijenskii, V. A.; Jagnov, V. A.; Solodovnikov, S. G.; Mazulin, A. V.; Ryjkov, V. M.

    1994-05-01

    Direct current breaker of a modular design is developed for the strong field tokamak power supply system. The power supply system comprises four 800 MW alternative current generators with 4 GJ flywheels, thyristor rectifiers providing inductive stores pumping by a current up to 100 kA for 1 - 4 sec. To form current pulses of various shapes in the tokamak windings current breakers are used with either pneumatic or explosive drive, at a current switching synchronously of not worse than 100 mks. Current breakers of these types require that the current conducting elements be replaced after each shot. For recent years vacuum arc quenching chambers with an axial magnetic field are successfully employed as repetitive performance current breakers, basically for currents up to 40 kA. In the report some results of researches of a vacuum switch modular are presented which we used as prototype switch for currents of the order of 100 kA.

  10. 30 CFR 75.800-4 - Testing, examination, and maintenance of circuit breakers; record.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Underground High-Voltage Distribution § 75.800-4 Testing, examination, and maintenance of circuit breakers... adjustment of all circuit breakers protecting high-voltage circuits which enter any underground area of the...

  11. Interruption of a dry-type transformer in no-load by a vacuum circuit-breaker

    NASA Astrophysics Data System (ADS)

    Vandenheuvel, W. M. C.; Daalder, J. E.; Boone, M. J. M.; Wilmes, L. A. H.

    1983-08-01

    Overvoltages generated during interruption of a dry type delta-star connected transformer in no load by a vacuum breaker were studied. During interruption of inrush current 37% of the phase-to-ground overvoltages were 5 pu, and 6% 7 pu. Comparison of experimental and theoretical results using Boyle's model shows no discrepancy for inrush currents and clean overvoltages from the steady-state interruption. Overvoltages due to repetitive reignitions (not covered by Boyle's model) are higher than the calculated values during steady-state switching.

  12. 46 CFR 111.30-4 - Circuit breakers removable from the front.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Circuit breakers removable from the front. 111.30-4 Section 111.30-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-4 Circuit breakers removable from the front...

  13. 46 CFR 111.30-4 - Circuit breakers removable from the front.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Circuit breakers removable from the front. 111.30-4 Section 111.30-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-4 Circuit breakers removable from the front...

  14. 46 CFR 111.30-4 - Circuit breakers removable from the front.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Circuit breakers removable from the front. 111.30-4 Section 111.30-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-4 Circuit breakers removable from the front...

  15. 46 CFR 111.30-4 - Circuit breakers removable from the front.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Circuit breakers removable from the front. 111.30-4 Section 111.30-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-4 Circuit breakers removable from the front...

  16. 46 CFR 111.30-4 - Circuit breakers removable from the front.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Circuit breakers removable from the front. 111.30-4 Section 111.30-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-4 Circuit breakers removable from the front...

  17. 48 CFR 225.7006 - Restriction on air circuit breakers for naval vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Restriction on air circuit breakers for naval vessels. 225.7006 Section 225.7006 Federal Acquisition Regulations System DEFENSE... on air circuit breakers for naval vessels. ...

  18. 48 CFR 225.7006 - Restriction on air circuit breakers for naval vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Restriction on air circuit breakers for naval vessels. 225.7006 Section 225.7006 Federal Acquisition Regulations System DEFENSE... on air circuit breakers for naval vessels. ...

  19. Influence of Gap Distance on Vacuum Arc Characteristics of Cup Type AMF Electrode in Vacuum Interrupters

    NASA Astrophysics Data System (ADS)

    Cheng, Shaoyong; Xiu, Shixin; Wang, Jimei; Shen, Zhengchao

    2006-11-01

    The greenhouse effect of SF6 is a great concern today. The development of high voltage vacuum circuit breakers becomes more important. The vacuum circuit breaker has minimum pollution to the environment. The vacuum interrupter is the key part of a vacuum circuit breaker. The interrupting characteristics in vacuum and arc-controlling technique are the main problems to be solved for a longer gap distance in developing high voltage vacuum interrupters. To understand the vacuum arc characteristics and provide effective technique to control vacuum arc in a long gap distance, the arc mode transition of a cup-type axial magnetic field electrode is observed by a high-speed charge coupled device (CCD) video camera under different gap distances while the arc voltage and arc current are recorded. The controlling ability of the axial magnetic field on vacuum arc obviously decreases when the gap distance is longer than 40 mm. The noise components and mean value of the arc voltage significantly increase. The effective method for controlling the vacuum arc characteristics is provided by long gap distances based on the test results. The test results can be used as a reference to develop high voltage and large capacity vacuum interrupters.

  20. Research on burnout fault of moulded case circuit breaker based on finite element simulation

    NASA Astrophysics Data System (ADS)

    Xue, Yang; Chang, Shuai; Zhang, Penghe; Xu, Yinghui; Peng, Chuning; Shi, Erwei

    2017-09-01

    In the failure event of molded case circuit breaker, overheating of the molded case near the wiring terminal has a very important proportion. The burnout fault has become an important factor restricting the development of molded case circuit breaker. This paper uses the finite element simulation software to establish the model of molded case circuit breaker by coupling multi-physics field. This model can simulate the operation and study the law of the temperature distribution. The simulation results show that the temperature near the wiring terminal, especially the incoming side of the live wire, of the molded case circuit breaker is much higher than that of the other areas. The steady-state and transient simulation results show that the temperature at the wiring terminals is abnormally increased by increasing the contact resistance of the wiring terminals. This is consistent with the frequent occurrence of burnout of the molded case in this area. Therefore, this paper holds that the burnout failure of the molded case circuit breaker is mainly caused by the abnormal increase of the contact resistance of the wiring terminal.

  1. Optimizing the switching time for 400 kV SF6 circuit breakers

    NASA Astrophysics Data System (ADS)

    Ciulica, D.

    2018-01-01

    This paper presents real-time voltage and current analysis for optimizing the wave switching point of the circuit breaker SF6. Circuit Breaker plays an important role in power systems. It provides protection for equipment in embedded stations in transport networks. SF6 Circuit Breaker is very important equipment in Power Systems, which is used for up to 400 kV due to its excellent performance. The controlled switching is used to eliminate transient modes and electrodynamic and dielectric charges in the network at manual switching of capacitor, shunt reactors and power transformers. These effects reduce the reliability and lifetime of the equipment installed on the network, or may lead to erroneous protection.

  2. 62. VIEW LOOKING NORTHWEST AT THE OIL FILLED CIRCUIT BREAKER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. VIEW LOOKING NORTHWEST AT THE OIL FILLED CIRCUIT BREAKER FOR GENERATOR NUMBER 1. CIRCUIT BREAKERS ARE AUTOMATED SWITCHES WHICH DISCONNECT THE GENERATORS FROM THE LINE WHEN SHORT CIRCUITS OCCUR. WHEN CIRCUITS INVOLVING HIGH CURRENTS AND VOLTAGES ARE BROKEN, THE AIR SURROUNDING MECHANICAL PARTS OF THE SWITCH BECOMES IONIZED AND CONTINUES TO CONDUCT ELECTRIC POWER ACROSS ANY GAP IN THE SWITCH CONTACTS. TO PREVENT THIS AND INSURE A POSITIVE INTERRUPTION OF CURRENT, THE SWITCH CONTACTS ARE IMMERSED IN A CONTAINER OF OIL. THE OIL DOES NOT SUPPORT THE FORMATION OF AN ARC AND EFFECTIVELY CUTS OFF THE CURRENT WHEN THE SWITCH CONTACTS ARE OPENED. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  3. 30 CFR 75.800-3 - Testing, examination and maintenance of circuit breakers; procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Testing, examination and maintenance of circuit breakers; procedures. 75.800-3 Section 75.800-3 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... High-Voltage Distribution § 75.800-3 Testing, examination and maintenance of circuit breakers...

  4. The Voltage Distribution Characteristics of a Hybrid Circuit Breaker During High Current Interruption

    NASA Astrophysics Data System (ADS)

    Cheng, Xian; Duan, Xiongying; Liao, Minfu; Huang, Zhihui; Luo, Yan; Zou, Jiyan

    2013-08-01

    Hybrid circuit breaker (HCB) technology based on a vacuum interrupter and a SF6 interrupter in series has become a new research direction because of the low-carbon requirements for high voltage switches. The vacuum interrupter has an excellent ability to deal with the steep rising part of the transient recovery voltage (TRV), while the SF6 interrupter can withstand the peak part of the voltage easily. An HCB can take advantage of the interrupters in the current interruption process. In this study, an HCB model based on the vacuum ion diffusion equations, ion density equation, and modified Cassie-Mayr arc equation is explored. A simulation platform is constructed by using a set of software called the alternative transient program (ATP). An HCB prototype is also designed, and the short circuit current is interrupted by the HCB under different action sequences of contacts. The voltage distribution of the HCB is analyzed through simulations and tests. The results demonstrate that if the vacuum interrupter withstands the initial TRV and interrupts the post-arc current first, then the recovery speed of the dielectric strength of the SF6 interrupter will be fast. The voltage distribution between two interrupters is determined by their post-arc resistance, which happens after current-zero, and subsequently, it is determined by the capacitive impedance after the post-arc current decays to zero.

  5. A New Test Method of Circuit Breaker Spring Telescopic Characteristics Based Image Processing

    NASA Astrophysics Data System (ADS)

    Huang, Huimin; Wang, Feifeng; Lu, Yufeng; Xia, Xiaofei; Su, Yi

    2018-06-01

    This paper applied computer vision technology to the fatigue condition monitoring of springs, and a new telescopic characteristics test method is proposed for circuit breaker operating mechanism spring based on image processing technology. High-speed camera is utilized to capture spring movement image sequences when high voltage circuit breaker operated. Then the image-matching method is used to obtain the deformation-time curve and speed-time curve, and the spring expansion and deformation parameters are extracted from it, which will lay a foundation for subsequent spring force analysis and matching state evaluation. After performing simulation tests at the experimental site, this image analyzing method could solve the complex problems of traditional mechanical sensor installation and monitoring online, status assessment of the circuit breaker spring.

  6. Vacuum breaker valve assembly

    DOEpatents

    Thompson, J.L.; Upton, H.A.

    1999-04-27

    Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening. 1 fig.

  7. Vacuum breaker valve assembly

    DOEpatents

    Thompson, Jeffrey L.; Upton, Hubert Allen

    1999-04-27

    Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening.

  8. 40 CFR Table 31 to Subpart G of... - Typical Number of Vacuum Breakers, NF6 and Roof Drains, a NF7

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Typical Number of Vacuum Breakers, NF6..., and Wastewater Pt. 63, Subpt. G, Table 31 Table 31 to Subpart G of Part 63—Typical Number of Vacuum Breakers, NF6 and Roof Drains, a NF7 Tank diameter D (feet) b No. of vacuum breakers, NF6 Pontoon roof...

  9. High speed hydraulically-actuated operating system for an electric circuit breaker

    DOEpatents

    Iman, Imdad

    1983-06-07

    This hydraulically-actuated operating system comprises a cylinder, a piston movable therein in an opening direction to open a circuit breaker, and an accumulator for supplying pressurized liquid to a breaker-opening piston-actuating space within the cylinder. A normally-closed valve between the accumulator and the actuating space is openable to allow pressurized liquid from the accumulator to flow through the valve into the actuating space to drive the piston in an opening direction. A dashpotting mechanism operating separately from the hydraulic actuating system is provided, thereby reducing flow restriction interference with breaker opening.

  10. High speed hydraulically-actuated operating system for an electric circuit breaker

    DOEpatents

    Iman, I.

    1983-06-07

    This hydraulically-actuated operating system comprises a cylinder, a piston movable therein in an opening direction to open a circuit breaker, and an accumulator for supplying pressurized liquid to a breaker-opening piston-actuating space within the cylinder. A normally-closed valve between the accumulator and the actuating space is openable to allow pressurized liquid from the accumulator to flow through the valve into the actuating space to drive the piston in an opening direction. A dashpotting mechanism operating separately from the hydraulic actuating system is provided, thereby reducing flow restriction interference with breaker opening. 3 figs.

  11. Optimization of the Switch Mechanism in a Circuit Breaker Using MBD Based Simulation

    PubMed Central

    Jang, Jin-Seok; Yoon, Chang-Gyu; Ryu, Chi-Young; Kim, Hyun-Woo; Bae, Byung-Tae; Yoo, Wan-Suk

    2015-01-01

    A circuit breaker is widely used to protect electric power system from fault currents or system errors; in particular, the opening mechanism in a circuit breaker is important to protect current overflow in the electric system. In this paper, multibody dynamic model of a circuit breaker including switch mechanism was developed including the electromagnetic actuator system. Since the opening mechanism operates sequentially, optimization of the switch mechanism was carried out to improve the current breaking time. In the optimization process, design parameters were selected from length and shape of each latch, which changes pivot points of bearings to shorten the breaking time. To validate optimization results, computational results were compared to physical tests with a high speed camera. Opening time of the optimized mechanism was decreased by 2.3 ms, which was proved by experiments. Switch mechanism design process can be improved including contact-latch system by using this process. PMID:25918740

  12. Fault current limiter and alternating current circuit breaker

    DOEpatents

    Boenig, Heinrich J.

    1998-01-01

    A solid-state circuit breaker and current limiter for a load served by an alternating current source having a source impedance, the solid-state circuit breaker and current limiter comprising a thyristor bridge interposed between the alternating current source and the load, the thyristor bridge having four thyristor legs and four nodes, with a first node connected to the alternating current source, and a second node connected to the load. A coil is connected from a third node to a fourth node, the coil having an impedance of a value calculated to limit the current flowing therethrough to a predetermined value. Control means are connected to the thyristor legs for limiting the alternating current flow to the load under fault conditions to a predetermined level, and for gating the thyristor bridge under fault conditions to quickly reduce alternating current flowing therethrough to zero and thereafter to maintain the thyristor bridge in an electrically open condition preventing the alternating current from flowing therethrough for a predetermined period of time.

  13. Fault current limiter and alternating current circuit breaker

    DOEpatents

    Boenig, H.J.

    1998-03-10

    A solid-state circuit breaker and current limiter are disclosed for a load served by an alternating current source having a source impedance, the solid-state circuit breaker and current limiter comprising a thyristor bridge interposed between the alternating current source and the load, the thyristor bridge having four thyristor legs and four nodes, with a first node connected to the alternating current source, and a second node connected to the load. A coil is connected from a third node to a fourth node, the coil having an impedance of a value calculated to limit the current flowing therethrough to a predetermined value. Control means are connected to the thyristor legs for limiting the alternating current flow to the load under fault conditions to a predetermined level, and for gating the thyristor bridge under fault conditions to quickly reduce alternating current flowing therethrough to zero and thereafter to maintain the thyristor bridge in an electrically open condition preventing the alternating current from flowing therethrough for a predetermined period of time. 9 figs.

  14. Research on Mechanical Fault Prediction Algorithm for Circuit Breaker Based on Sliding Time Window and ANN

    NASA Astrophysics Data System (ADS)

    Wang, Xiaohua; Rong, Mingzhe; Qiu, Juan; Liu, Dingxin; Su, Biao; Wu, Yi

    A new type of algorithm for predicting the mechanical faults of a vacuum circuit breaker (VCB) based on an artificial neural network (ANN) is proposed in this paper. There are two types of mechanical faults in a VCB: operation mechanism faults and tripping circuit faults. An angle displacement sensor is used to measure the main axle angle displacement which reflects the displacement of the moving contact, to obtain the state of the operation mechanism in the VCB, while a Hall current sensor is used to measure the trip coil current, which reflects the operation state of the tripping circuit. Then an ANN prediction algorithm based on a sliding time window is proposed in this paper and successfully used to predict mechanical faults in a VCB. The research results in this paper provide a theoretical basis for the realization of online monitoring and fault diagnosis of a VCB.

  15. Investigation of Dielectric Breakdown Characteristics for Double-break Vacuum Interrupter and Dielectric Breakdown Probability Distribution in Vacuum Interrupter

    NASA Astrophysics Data System (ADS)

    Shioiri, Tetsu; Asari, Naoki; Sato, Junichi; Sasage, Kosuke; Yokokura, Kunio; Homma, Mitsutaka; Suzuki, Katsumi

    To investigate the reliability of equipment of vacuum insulation, a study was carried out to clarify breakdown probability distributions in vacuum gap. Further, a double-break vacuum circuit breaker was investigated for breakdown probability distribution. The test results show that the breakdown probability distribution of the vacuum gap can be represented by a Weibull distribution using a location parameter, which shows the voltage that permits a zero breakdown probability. The location parameter obtained from Weibull plot depends on electrode area. The shape parameter obtained from Weibull plot of vacuum gap was 10∼14, and is constant irrespective non-uniform field factor. The breakdown probability distribution after no-load switching can be represented by Weibull distribution using a location parameter. The shape parameter after no-load switching was 6∼8.5, and is constant, irrespective of gap length. This indicates that the scatter of breakdown voltage was increased by no-load switching. If the vacuum circuit breaker uses a double break, breakdown probability at low voltage becomes lower than single-break probability. Although potential distribution is a concern in the double-break vacuum cuicuit breaker, its insulation reliability is better than that of the single-break vacuum interrupter even if the bias of the vacuum interrupter's sharing voltage is taken into account.

  16. Moving characteristics of electrodes for vacuum circuit breaker

    NASA Astrophysics Data System (ADS)

    Yuan, Shun; Wang, Jimei

    1994-05-01

    This paper analyzes the effect of the gap of electrodes on the state of vacuum arc by experiment and theory. And the model of vacuum arc is set up. The optimal gap can be deduced from controlling the vacuum arc to be diffusion state, in order to get the optimal moving characteristics of electrodes.

  17. Remote control circuit breaker evaluation testing. [for space shuttles

    NASA Technical Reports Server (NTRS)

    Bemko, L. M.

    1974-01-01

    Engineering evaluation tests were performed on several models/types of remote control circuit breakers marketed in an attempt to gain some insight into their potential suitability for use on the space shuttle vehicle. Tests included the measurement of several electrical and operational performance parameters under laboratory ambient, space simulation, acceleration and vibration environmental conditions.

  18. Cathode surface effects and H.F.-behaviour of vacuum arcs

    NASA Astrophysics Data System (ADS)

    Fu, Yan Hong

    To gain a better understanding of the essential processes occurring during a vacuum arc interruption for the further development of the vacuum arc circuit breaker, cathode spot behavior, current interruption, dielectrical recovery and overvoltage generation are investigated. An experimental study on cathode spot behavior of the DC vacuum arc in relation to cathode surface roughness and a qualitative physical model to interpret the results are reported. An experimental investigation on the High Frequency (HF) current interruption, multiple recognitions and voltage escalation phenomena is reported. A calculation program to predict the level of overvoltages generated by the operation of a vacuum breaker in a realistic single phase circuit is developed. Detailed results are summarized.

  19. The original westinghouse circuit breakers, manufactured 7/11/27. Utility room, to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    The original westinghouse circuit breakers, manufactured 7/11/27. Utility room, to north. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  20. 37. SAR2, SHOWING OIL CIRCUIT BREAKERS (ABOVE) AND GENERATOR FIELD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. SAR-2, SHOWING OIL CIRCUIT BREAKERS (ABOVE) AND GENERATOR FIELD COIL CONTROL RHEOSTATS (BELOW). SCE negative no. 10331, November 1, 1923. Photograph by G. Haven Bishop. - Santa Ana River Hydroelectric System, SAR-2 Powerhouse, Redlands, San Bernardino County, CA

  1. "Report to the Legislature on": The Implementation of the Special Education Reimbursement ("Circuit Breaker") Program. Line-Item 7061-0012

    ERIC Educational Resources Information Center

    Massachusetts Department of Education, 2008

    2008-01-01

    This paper reports on the implementation of the Special Education Reimbursement ("Circuit Breaker") Program. Fiscal Year 2007 is the fourth year implementing the Circuit Breaker reimbursement program which provides additional state support for students with disabilities. School districts are eligible for a reimbursement of eligible costs…

  2. 30 CFR 75.601-1 - Short circuit protection; ratings and settings of circuit breakers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (amperes) 14 50 12 75 10 150 8 200 6 300 4 500 3 600 2 800 1 1,000 1/0 1,250 2/0 1,500 3/0 2,000 4/0 2,500... of circuit breakers. 75.601-1 Section 75.601-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES...

  3. Hydraulically-actuated operating system for an electric circuit breaker

    DOEpatents

    Barkan, Philip; Imam, Imdad

    1978-01-01

    This hydraulically-actuated operating system comprises a cylinder, a piston movable therein in an opening direction to open a circuit breaker, and an accumulator for supplying pressurized liquid to a piston-actuating space within the cylinder. A normally-closed valve between the accumulator and the actuating space is openable to allow pressurized liquid from the accumulator to flow through the valve into the actuating space to drive the piston in an opening direction. A vent is located hydraulically between the actuating space and the valve for affording communication between said actuating space and a low pressure region. Flow control means is provided for restricting leakage through said vent to a rate that prevents said leakage from substantially detracting from the development of pressure within said actuatng space during the period from initial opening of the valve to the time when said piston has moved through most of its opening stroke. Following such period and while the valve is still open, said flow control means allows effective leakage through said vent. The accumulator has a limited capacity that results in the pressure within said actuating space decaying promptly to a low value as a result of effective leakage through said vent after the piston has moved through a circuit-breaker opening stroke and while the valve is in its open state. Means is provided for resetting the valve to its closed state in response to said pressure decay in the actuating space.

  4. The Implications of the Use of Parental Choice as a Legal "Circuit Breaker"

    ERIC Educational Resources Information Center

    Mead, Julie F.; Lewis, Maria M.

    2016-01-01

    This study explores four instances where parental choice has been employed as a legal "circuit breaker": (a) First Amendment Establishment Clause cases related to public funding, (b) Fourteenth Amendment Equal Protection cases regarding race-conscious student assignment, (c) Title IX regulations concerning single-sex education, and (d) a…

  5. Self-consistent radiation-based simulation of electric arcs: II. Application to gas circuit breakers

    NASA Astrophysics Data System (ADS)

    Iordanidis, A. A.; Franck, C. M.

    2008-07-01

    An accurate and robust method for radiative heat transfer simulation for arc applications was presented in the previous paper (part I). In this paper a self-consistent mathematical model based on computational fluid dynamics and a rigorous radiative heat transfer model is described. The model is applied to simulate switching arcs in high voltage gas circuit breakers. The accuracy of the model is proven by comparison with experimental data for all arc modes. The ablation-controlled arc model is used to simulate high current PTFE arcs burning in cylindrical tubes. Model accuracy for the lower current arcs is evaluated using experimental data on the axially blown SF6 arc in steady state and arc resistance measurements close to current zero. The complete switching process with the arc going through all three phases is also simulated and compared with the experimental data from an industrial circuit breaker switching test.

  6. Switching Circuit for Shop Vacuum System

    NASA Technical Reports Server (NTRS)

    Burley, R. K.

    1987-01-01

    No internal connections to machine tools required. Switching circuit controls vacuum system draws debris from grinders and sanders in machine shop. Circuit automatically turns on vacuum system whenever at least one sander or grinder operating. Debris safely removed, even when operator neglects to turn on vacuum system manually. Pickup coils sense alternating magnetic fields just outside operating machines. Signal from any coil or combination of coils causes vacuum system to be turned on.

  7. Study of switching electric circuits with DC hybrid breaker, one stage

    NASA Astrophysics Data System (ADS)

    Niculescu, T.; Marcu, M.; Popescu, F. G.

    2016-06-01

    The paper presents a method of extinguishing the electric arc that occurs between the contacts of direct current breakers. The method consists of using an LC type extinguishing group to be optimally sized. From this point of view is presented a theoretical approach to the phenomena that occurs immediately after disconnecting the load and the specific diagrams are drawn. Using these, the elements extinguishing group we can choose. At the second part of the paper there is presented an analyses of the circuit switching process by decomposing the process in particular time sequences. For every time interval there was conceived a numerical simulation model in MATLAB-SIMULINK medium which integrates the characteristic differential equation and plots the capacitor voltage variation diagram and the circuit dumping current diagram.

  8. The Working of Circuit Breakers Within Percolation Models for Financial Markets

    NASA Astrophysics Data System (ADS)

    Ehrenstein, Gudrun; Westerhoff, Frank

    We use a modified Cont-Bouchaud model to explore the effectiveness of trading breaks. The modifications include that the trading activity of the market participants depends positively on historical volatility and that the orders of the agents are conditioned on the observed mispricing. Trading breaks, also called circuit breakers, interrupt the trading process when prices are about to exceed a pre-specified limit. We find that trading breaks are a useful instrument to stabilize financial markets. In particular, trading breaks may reduce price volatility and deviations from fundamentals.

  9. One-dimensional particle-in-cell simulation on the influence of electron and ion temperature on the sheath expansion process in the post-arc stage of vacuum circuit breaker

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mo, Yongpeng; Shi, Zongqian; Jia, Shenli

    2015-02-15

    The inter-contact region of vacuum circuit breakers is filled with residual plasma at the moment when the current is zero after the burning of metal vapor arc. The residual plasma forms an ion sheath in front of the post-arc cathode. The sheath then expands towards the post-arc anode under the influence of a transient recovery voltage. In this study, a one-dimensional particle-in-cell model is developed to investigate the post-arc sheath expansion. The influence of ion and electron temperatures on the decrease in local plasma density at the post-arc cathode side and post-arc anode side is discussed. When the decay inmore » the local plasma density develops from the cathode and anode sides into the high-density region and merges, the overall plasma density in the inter-contact region begins to decrease. Meanwhile, the ion sheath begins to expand faster. Furthermore, the theory of ion rarefaction wave only explains quantitatively the decrease in the overall plasma density at relatively low ion temperatures. With the increase of ion temperature to certain extent, another possible reason for the decrease in the overall plasma density is proposed and results from the more active thermal diffusion of plasma.« less

  10. One-dimensional particle-in-cell simulation on the influence of electron and ion temperature on the sheath expansion process in the post-arc stage of vacuum circuit breaker

    NASA Astrophysics Data System (ADS)

    Mo, Yongpeng; Shi, Zongqian; Jia, Shenli; Wang, Lijun

    2015-02-01

    The inter-contact region of vacuum circuit breakers is filled with residual plasma at the moment when the current is zero after the burning of metal vapor arc. The residual plasma forms an ion sheath in front of the post-arc cathode. The sheath then expands towards the post-arc anode under the influence of a transient recovery voltage. In this study, a one-dimensional particle-in-cell model is developed to investigate the post-arc sheath expansion. The influence of ion and electron temperatures on the decrease in local plasma density at the post-arc cathode side and post-arc anode side is discussed. When the decay in the local plasma density develops from the cathode and anode sides into the high-density region and merges, the overall plasma density in the inter-contact region begins to decrease. Meanwhile, the ion sheath begins to expand faster. Furthermore, the theory of ion rarefaction wave only explains quantitatively the decrease in the overall plasma density at relatively low ion temperatures. With the increase of ion temperature to certain extent, another possible reason for the decrease in the overall plasma density is proposed and results from the more active thermal diffusion of plasma.

  11. Breakdown Conditioning Chacteristics of Precision-Surface-Treatment-Electrode in Vacuum

    NASA Astrophysics Data System (ADS)

    Kato, Kastumi; Fukuoka, Yuji; Inagawa, Yukihiko; Saitoh, Hitoshi; Sakaki, Masayuki; Okubo, Hitoshi

    Breakdown (BD) characteristics in vacuum are strongly dependent on the electrode surface condition, like the surface roughness etc. Therefore, in order to develop a high voltage vacuum circuit breaker, it is important to optimize the surface treatment process. This paper discusses about the effect of precision-surface-treatment of the electrode on breakdown conditioning characteristics under non-uniform electric field in vacuum. Experimental results reveal that the electrode surface treatment affects the conditioning process, especially the BD voltage and the BD field strength at the initial stage of the conditioning.

  12. Optical Analysis Of The Vacuum Arc Plasma Generated In Cup-Shape Contacts

    NASA Astrophysics Data System (ADS)

    Pavelescu, G.; Pavelescu, D.; Dumitrescu, G.; Anghelita, P.; Gherendi, F.

    2007-04-01

    In this paper are presented the results of the optical analysis on the rotating arc plasma, generated in the vacuum low voltage circuit breaker with cup-shaped contacts. An adequate experimental setup was used for single shot time and spatial resolved spectroscopy in order to analyze the evolution of the vacuum arc plasma. Different current interruption situations are correlated with plasma spectral diagnosis. The study is aimed to contribute to a better understanding of the complex phenomena that take place in the interruption process of high currents that appears in the short-circuit regime of electrical networks.

  13. Development of a multiperspective optical measuring system for investigating decaying switching arcs at the nozzle exit of circuit breakers.

    PubMed

    Stoffels, M; Simon, S; Nikolic, P G; Stoller, P; Carstensen, J

    2017-03-01

    High-voltage gas circuit breakers, which play an important role in the operation and protection of the power grid, function by drawing an arc between two contacts and then extinguishing it by cooling it using a transonic gas flow. Improving the design of circuit breakers requires an understanding of the physical processes in the interruption of the arc, particularly during the zero crossing of the alternating current (the point in time when the arc can be interrupted). Most diagnostic techniques currently available focus on measurement of current, voltage, and gas pressure at defined locations. However, these integral properties do not give sufficient insight into the arc physics. To understand the current interruption process, spatially resolved information about the density, temperature, and conductivity of the arc and surrounding gas flow is needed. Owing to the three-dimensional, unstable nature of the arc in a circuit breaker, especially near current zero, a spatially resolved, tomographic diagnostic technique is required that is capable of freezing the rapid, transient behavior and that is insensitive to the vibrations and electromagnetic interference inherent in the interruption of short-circuit current arcs. Here a new measurement system, based on background-oriented schlieren (BOS) imaging, is presented and assessed. BOS imaging using four beams consisting of white light sources, a background pattern, imaging optics, and a camera permits measurement of the line-of-sight integrated refractive index. Tomographic reconstruction is used to determine the three-dimensional, spatially resolved index of refraction distribution that in turn is used to calculate the density. The quantitative accuracy of a single beam of the BOS setup is verified by using a calibration lens with a known focal length. The ability of the tomographic reconstruction to detect asymmetric features of the arc and surrounding gas flow is assessed semiquantitatively using a nozzle that

  14. A No-Arc DC Circuit Breaker Based on Zero-Current Interruption

    NASA Astrophysics Data System (ADS)

    Xiang, Xuewei; Chai, Jianyun; Sun, Xudong

    2017-05-01

    A dc system has no natural current zero-crossing point, so a dc arc is more difficult to extinguish than an ac arc. In order to effectively solve the problem of the dc arc, this paper proposes a dc circuit breaker (DCCB) capable of implementing a no-arc interruption. The proposed DCCB includes a main branch consisting of a mechanical switch, a diode and a current-limiting inductor, a semi-period resonance circuit consisting of a diode, an inductor and a capacitor, and a buffer branch consisting of a capacitor, a thyristor and a resistor. The mechanical switch is opened in a zero-current state, and the overvoltage caused by the counter electromotive force of the inductor does not exist. Meanwhile, the capacitor has a buffering effect on the voltage. The rising of the voltage of the mechanical switch is slower than the rising of the insulating strength of a contact gap of the mechanical switch, resulting in the contact gap not able to be broken down. Thus, the arc cannot be generated. The simulation results show that the proposed DCCB does not generate the arc in the interruption process, the rise rate of the short circuit current can be effectively limited, and the short circuit fault point can be rapidly isolated from the dc power supply.

  15. The Relationship between the Current Waveform just before the Current Zero and the Interruption Ability in the High-speed VCB

    NASA Astrophysics Data System (ADS)

    Niwa, Yoshimitsu; Matsuzaki, Jun; Yokokura, Kunio

    The high-speed vacuum circuit breaker, which forced the fault current to zero was investigated. The test circuit breaker consisted of a vacuum interrupter and a high frequency current source. The vacuum interrupter, which had the axial magnetic field electrode and the disk shape electrode, was tested. The arcing period of the high-speed vacuum circuit breaker is much shorter than that of conventional circuit breaker. The arc behavior of the test electrodes immediately after the contact separation was observed by a high-speed video camcorder. The relation between the current waveform just before the current zero and the interruption ability by varying the high frequency current source was investigated experimentally. The results demonstrate the interruption ability and the arc behavior of the high-speed vacuum circuit breaker. The high current interruption was made possible by the low current period just before the current zero, although the arcing time is short and the arc is concentrated.

  16. Study on the Mathematical Model of Dielectric Recovery Characteristics in High Voltage SF6 Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Lin, Xin; Wang, Feiming; Xu, Jianyuan; Xia, Yalong; Liu, Weidong

    2016-03-01

    According to the stream theory, this paper proposes a mathematical model of the dielectric recovery characteristic based on the two-temperature ionization equilibrium equation. Taking the dynamic variation of charged particle's ionization and attachment into account, this model can be used in collaboration with the Coulomb collision model, which gives the relationship of the heavy particle temperature and electron temperature to calculate the electron density and temperature under different pressure and electric field conditions, so as to deliver the breakdown electric field strength under different pressure conditions. Meanwhile an experiment loop of the circuit breaker has been built to measure the breakdown voltage. It is shown that calculated results are in conformity with experiment results on the whole while results based on the stream criterion are larger than experiment results. This indicates that the mathematical model proposed here is more accurate for calculating the dielectric recovery characteristic, it is derived from the stream model with some improvement and refinement and has great significance for increasing the simulation accuracy of circuit breaker's interruption characteristic. supported by Science and Technology Project of State Grid Corporation of China (No. GY17201200063), National Natural Science Foundation of China (No. 51277123), Basic Research Project of Liaoning Key Laboratory of Education Department (LZ2015055)

  17. Space and time resolved representation of a vacuum arc light emission

    NASA Astrophysics Data System (ADS)

    Georgescu, N.; Sandolache, G.; Zoita, V.

    1999-04-01

    An optoelectronic multichannel detection system for the study of the visible light emission of a vacuum circuit breaker arc is described. The system consists of two multiple slit collimator assemblies coupled directly to the arc discharge chamber and an electronic detection part. The light emitted by the arc is collected by the two collimator assemblies and is transmitted through optical fibres to the electronic detection part. By using a new, simple computational method two-dimensional plots of the vacuum arc light emission at different times are obtained.

  18. 30 CFR 75.900 - Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-phase alternating current equipment; circuit breakers. 75.900 Section 75.900 Mineral Resources MINE... Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit breakers. [Statutory Provisions] Low- and medium-voltage power circuits serving three-phase alternating current...

  19. 133. View of former oil switch breaker room (on second ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    133. View of former oil switch breaker room (on second floor, north of the control room), looking south. The oil switch breakers were replaced with vacuum switches, along the wall to the right. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  20. Feasibility analysis of a novel hybrid-type superconducting circuit breaker in multi-terminal HVDC networks

    NASA Astrophysics Data System (ADS)

    Khan, Umer Amir; Lee, Jong-Geon; Seo, In-Jin; Amir, Faisal; Lee, Bang-Wook

    2015-11-01

    Voltage source converter-based HVDC systems (VSC-HVDC) are a better alternative than conventional thyristor-based HVDC systems, especially for developing multi-terminal HVDC systems (MTDC). However, one of the key obstacles in developing MTDC is the absence of an adequate protection system that can quickly detect faults, locate the faulty line and trip the HVDC circuit breakers (DCCBs) to interrupt the DC fault current. In this paper, a novel hybrid-type superconducting circuit breaker (SDCCB) is proposed and feasibility analyses of its application in MTDC are presented. The SDCCB has a superconducting fault current limiter (SFCL) located in the main current path to limit fault currents until the final trip signal is received. After the trip signal the IGBT located in the main line commutates the current into a parallel line where DC current is forced to zero by the combination of IGBTs and surge arresters. Fault simulations for three-, four- and five-terminal MTDC were performed and SDCCB performance was evaluated in these MTDC. Passive current limitation by SFCL caused a significant reduction of fault current interruption stress in the SDCCB. It was observed that the DC current could change direction in MTDC after a fault and the SDCCB was modified to break the DC current in both the forward and reverse directions. The simulation results suggest that the proposed SDCCB could successfully suppress the DC fault current, cause a timely interruption, and isolate the faulty HVDC line in MTDC.

  1. Vacuum die attach for integrated circuits

    DOEpatents

    Schmitt, Edward H.; Tuckerman, David B.

    1991-01-01

    A thin film eutectic bond for attaching an integrated circuit die to a circuit substrate is formed by coating at least one bonding surface on the die and substrate with an alloying metal, assembling the die and substrate under compression loading, and heating the assembly to an alloying temperature in a vacuum. A very thin bond, 10 microns or less, which is substantially void free, is produced. These bonds have high reliability, good heat and electrical conduction, and high temperature tolerance. The bonds are formed in a vacuum chamber, using a positioning and loading fixture to compression load the die, and an IR lamp or other heat source. For bonding a silicon die to a silicon substrate, a gold silicon alloy bond is used. Multiple dies can be bonded simultaneously. No scrubbing is required.

  2. Vacuum die attach for integrated circuits

    DOEpatents

    Schmitt, E.H.; Tuckerman, D.B.

    1991-09-10

    A thin film eutectic bond for attaching an integrated circuit die to a circuit substrate is formed by coating at least one bonding surface on the die and substrate with an alloying metal, assembling the die and substrate under compression loading, and heating the assembly to an alloying temperature in a vacuum. A very thin bond, 10 microns or less, which is substantially void free, is produced. These bonds have high reliability, good heat and electrical conduction, and high temperature tolerance. The bonds are formed in a vacuum chamber, using a positioning and loading fixture to compression load the die, and an IR lamp or other heat source. For bonding a silicon die to a silicon substrate, a gold silicon alloy bond is used. Multiple dies can be bonded simultaneously. No scrubbing is required. 1 figure.

  3. The Generating Mechanism of Non-Sustained Disruptive Discharges in Vacuum Interrupters

    NASA Astrophysics Data System (ADS)

    Hara, Daisuke; Taki, Masayuki; Tanaka, Hitoshi; Okawa, Mikio; Yanabu, Satoru

    To develop vacuum circuit breaker (VCB) for higher voltage application, it may be important to understand generating mechanism and its influence of non-sustained disruptive discharges (NSDD) to the systems. So, we carried out the tests using equivalent testing circuit and observed the contacts after testing, For the test, by using commercial vacuum circuit interrupters, AC voltages of 50Hz was applied between contacts for 4 seconds after current interruption, and measured generating frequencies of NSDD vs. the voltages and vs. currents. Typical contact material used in the commercial switching equipment, such as AgWC, CuW, CuCr were tested and compared. Then CuCr's of different composition and manufacturing process are investigated. And CuCr-50 (manufactured by melting process) showed the best performance in all tests. We point out that surface condition may affect the generation of NSDD and also conditioning effect is very important.

  4. Fundamental properties of high-temperature SF6 mixed with CO2 as a replacement for SF6 in high-voltage circuit breakers

    NASA Astrophysics Data System (ADS)

    Wang, Weizong; Rong, Mingzhe; Wu, Yi; Yan, Joseph D.

    2014-06-01

    Sulfur hexafluoride (SF6) gas, used widely in high-voltage circuit breakers, can produce a remarkable greenhouse effect if released into the atmosphere. Fundamental properties of SF6 mixed with CO2 at high temperatures are presented in this paper, considering their reduction of adverse impact on the environment as a replacement for pure SF6 in high-voltage circuit breakers: to the knowledge of the authors, related data have not been reported in the literature. The species composition and thermodynamic properties (mass density, enthalpy and specific heat at constant pressure) are determined by the method of Gibbs free energy minimization, using standard thermodynamic tables. The transport properties, including viscosity, thermal conductivity and electrical conductivity, are evaluated by using the Chapman-Enskog method expanded up to the third-order approximation (second order for viscosity). Particular attention is paid to the establishment of a collision integral database related to a reacting species system containing basic elements of carbon, oxygen and sulfur as well as fluoride by the use of recent cross sections or interaction potentials available in the literature. The calculations, which assume a local thermodynamic equilibrium, are performed in the temperature range 300 to 30 000 K for different pressures between 0.01 and 1.6 MPa. The results obtained are compared to those of previously published studies, and the reasons for discrepancies are analysed. An evaluation of the current interruption performance by adding CO2 to SF6 is discussed from a microscopic point of view. The results provide reliable reference data for the simulation of switching arcs in high-voltage circuit breakers in SF6-CO2 mixtures.

  5. Numerical study of turbulence-influence mechanism on arc characteristics in an air direct current circuit breaker

    NASA Astrophysics Data System (ADS)

    Wu, Mingliang; Yang, Fei; Rong, Mingzhe; Wu, Yi; Qi, Yang; Cui, Yufei; Liu, Zirui; Guo, Anxiang

    2016-04-01

    This paper focuses on the numerical investigation of arc characteristics in an air direct current circuit breaker (air DCCB). Using magneto-hydrodynamics (MHD) theory, 3D laminar model and turbulence model are constructed and calculated. The standard k-epsilon model is utilized to consider the turbulence effect in the arc chamber of the DCCB. Several important phenomena are found: the arc column in the turbulence-model case is more extensive, moves much more slowly than the counterpart in the laminar-model case, and shows stagnation at the entrance of the chamber, unlike in the laminar-model case. Moreover, the arc voltage in the turbulence-model case is much lower than in the laminar-model case. However, the results in the turbulence-model case show a much better agreement with the results of the breaking experiments under DC condition than in the laminar-model case, which is contradictory to the previous conclusions from the arc researches of both the low-voltage circuit breaker and the sulfur hexafluoride (SF6) nozzle. First, in the previous air-arc research of the low-voltage circuit breaker, it is assumed that the air plasma inside the chamber is in the state of laminar, and the laminar-model application gives quite satisfactory results compared with the experiments, while in this paper, the laminar-model application works badly. Second, the turbulence-model application in the arc research of the SF6-nozzle performs much better and gives higher arc voltage than the laminar-model application does, whereas in this paper, the turbulence-model application predicts lower arc voltage than the laminar-model application does. Based on the analysis of simulation results in detail, the mechanism of the above phenomena is revealed. The transport coefficients are strongly changed by turbulence, which will enhance the arc diffusion and make the arc volume much larger. Consequently, the arc appearance and the distribution of Lorentz force in the turbulence-model case

  6. Simulation of the Process of Arc Energy-Effect in High Voltage Auto-Expansion SF6 Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Rong, Mingzhe; Yang, Qian; Fan, Chunduo

    2005-12-01

    A new magnetic hydro-dynamics (MHD) model of arc in H.V. auto-expansion SF6 circuit breaker that takes into consideration nozzle ablation due to both radiation and thermal conduction is presented in this paper. The effect of PTFE (polytetrafluorethylene) vapor is considered in the mass, momentum and energy conservation equations of the constructed model. Then, the gas flow fields with and without conduction considered are simulated. By comparing the aforementioned two results, it is indicated that the arc's maximal temperature with conduction considered is 90 percent of that without considering conduction.

  7. A novel post-arc current measuring equipment based on vacuum arc commutation and arc blow

    NASA Astrophysics Data System (ADS)

    Liao, Minfu; Ge, Guowei; Duan, Xiongying; Huang, Zhihui

    2017-07-01

    The paper proposes a novel post-arc current measuring equipment (NPACME), which is based on the vacuum arc commutation and magnetic arc blow. The NPACME is composed of the vacuum circuit breaker (VCB), shunt resistor, protective gap, high-precision current sensor and externally applied transverse magnetic field (ETMF). The prototype of the NPACME is designed and controlled by optical fiber communications. The vacuum arc commutation between the vacuum arc and the shunt resistor with ETMF is investigated. The test platform is established in the synthetic short-circuit test and the vacuum arc is observed by the high speed CMOS camera. The mathematic description of the vacuum arc commutation is obtained. Based on the current commutation characteristic, the parameters of the NPACME are optimized and the post-arc current is measured. The measuring result of the post-arc current is accurate with small interference and the post-arc charge is obtained. The experimental results verify that the NPACME is correct and accurate, which can be used to measure the post-arc characteristic in breaking test.

  8. Resonant Circuits and Introduction to Vacuum Tubes, Industrial Electronics 2: 9325.03. Course Outline.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    The 135 clock-hour course for the 11th year consists of outlines for blocks of instruction on series resonant circuits, parallel resonant circuits, transformer theory and application, vacuum tube fundamentals, diode vacuum tubes, triode tube construction and parameters, vacuum tube tetrodes and pentodes, beam-power and multisection tubes, and…

  9. Insulation co-ordination aspects for power stations with generator circuit-breakers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sanders, M.; Koeppl, G.; Kreuzer, J.

    1995-07-01

    The generator circuit-breaker (gen. c.b.) located between the generator and the step-up transformer, is now being applied world-wide. It has become a recognized electrical component of power stations which is largely due to economical advantages and increased power station availability. Technical protection considerations for power stations have always been the reason for discussion and the object of improvement. With the use of a gen. c.b., some points of view need to be considered anew. Not only the protection system in case of fault conditions will be influenced, but also the insulation co-ordination philosophy. Below the results of some calculations concerningmore » expected overvoltages are presented. These calculations are based on a transformer rated 264/15.5kV, 220 MVA. But the results are transferable to other power plants. Some measurements carried out on a transformer of the same rating complement the calculations. The findings may contribute to an improvement in insulation co-ordination and protection of the electrical system generator--step-up transformer.« less

  10. A High Power Solid State Circuit Breaker for Military Hybrid Electric Vehicle Applications

    DTIC Science & Technology

    2012-08-01

    the SSCB to isolate a fault, breaker opening is latched and can be reset to reclose the breaker via remote logic input. SSCB state and health...rated load current (125 A). Figure 10 shows that after the SSCB detects a fault and opens, it can also be repeatedly reclosed remotely to attempt to

  11. Numerical study of turbulence-influence mechanism on arc characteristics in an air direct current circuit breaker

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wu, Mingliang; Yang, Fei, E-mail: yfei2007@mail.xjtu.edu.cn; Rong, Mingzhe

    This paper focuses on the numerical investigation of arc characteristics in an air direct current circuit breaker (air DCCB). Using magneto-hydrodynamics (MHD) theory, 3D laminar model and turbulence model are constructed and calculated. The standard k-epsilon model is utilized to consider the turbulence effect in the arc chamber of the DCCB. Several important phenomena are found: the arc column in the turbulence-model case is more extensive, moves much more slowly than the counterpart in the laminar-model case, and shows stagnation at the entrance of the chamber, unlike in the laminar-model case. Moreover, the arc voltage in the turbulence-model case ismore » much lower than in the laminar-model case. However, the results in the turbulence-model case show a much better agreement with the results of the breaking experiments under DC condition than in the laminar-model case, which is contradictory to the previous conclusions from the arc researches of both the low-voltage circuit breaker and the sulfur hexafluoride (SF6) nozzle. First, in the previous air-arc research of the low-voltage circuit breaker, it is assumed that the air plasma inside the chamber is in the state of laminar, and the laminar-model application gives quite satisfactory results compared with the experiments, while in this paper, the laminar-model application works badly. Second, the turbulence-model application in the arc research of the SF6-nozzle performs much better and gives higher arc voltage than the laminar-model application does, whereas in this paper, the turbulence-model application predicts lower arc voltage than the laminar-model application does. Based on the analysis of simulation results in detail, the mechanism of the above phenomena is revealed. The transport coefficients are strongly changed by turbulence, which will enhance the arc diffusion and make the arc volume much larger. Consequently, the arc appearance and the distribution of Lorentz force in the turbulence

  12. 46 CFR 28.860 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... current carrying conductor must be protected in accordance with its current carrying capacity by a circuit breaker or fuse at the connection to the switchboard or distribution panel bus. (d) Each circuit breaker...

  13. 46 CFR 28.860 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... current carrying conductor must be protected in accordance with its current carrying capacity by a circuit breaker or fuse at the connection to the switchboard or distribution panel bus. (d) Each circuit breaker...

  14. Analytical Analysis and Case Study of Transient Behavior of Inrush Current in Power Transformer for Designing of Efficient Circuit Breakers

    NASA Astrophysics Data System (ADS)

    Harmanpreet, Singh, Sukhwinder; Kumar, Ashok; Kaur, Parneet

    2010-11-01

    Stability & security are main aspects in electrical power systems. Transformer protection is major issue of concern to system operation. There are many mall-trip cases of transformer protection are caused by inrush current problems. The phenomenon of transformer inrush current has been discussed in many papers since 1958. In this paper analytical analysis of inrush current in a transformer switched on dc and ac supply has been done. This analysis will help in design aspects of circuit breakers for better performance.

  15. Structure design of and experimental research on a two-stage laval foam breaker for foam fluid recycling.

    PubMed

    Wang, Jin-song; Cao, Pin-lu; Yin, Kun

    2015-07-01

    Environmental, economical and efficient antifoaming technology is the basis for achievement of foam drilling fluid recycling. The present study designed a novel two-stage laval mechanical foam breaker that primarily uses vacuum generated by Coanda effect and Laval principle to break foam. Numerical simulation results showed that the value and distribution of negative pressure of two-stage laval foam breaker were larger than that of the normal foam breaker. Experimental results showed that foam-breaking efficiency of two-stage laval foam breaker was higher than that of normal foam breaker, when gas-to-liquid ratio and liquid flow rate changed. The foam-breaking efficiency of normal foam breaker decreased rapidly with increasing foam stability, whereas the two-stage laval foam breaker remained unchanged. Foam base fluid would be recycled using two-stage laval foam breaker, which would reduce the foam drilling cost sharply and waste disposals that adverse by affect the environment.

  16. Mems: Platform for Large-Scale Integrated Vacuum Electronic Circuits

    DTIC Science & Technology

    2017-03-20

    SECURITY CLASSIFICATION OF: The objective of the LIVEC advanced study project was to develop a platform for large-scale integrated vacuum electronic ...Distribution Unlimited UU UU UU UU 20-03-2017 1-Jul-2014 30-Jun-2015 Final Report: MEMS Platform for Large-Scale Integrated Vacuum Electronic ... Electronic Circuits (LIVEC) Contract No: W911NF-14-C-0093 COR Dr. James Harvey U.S. ARO RTP, NC 27709-2211 Phone: 702-696-2533 e-mail

  17. Electrical short circuit and current overload tests on aircraft wiring

    NASA Technical Reports Server (NTRS)

    Cahill, Patricia

    1995-01-01

    The findings of electrical short circuit and current overload tests performed on commercial aircraft wiring are presented. A series of bench-scale tests were conducted to evaluate circuit breaker response to overcurrent and to determine if the wire showed any visible signs of thermal degradation due to overcurrent. Three types of wire used in commercial aircraft were evaluated: MIL-W-22759/34 (150 C rated), MIL-W-81381/12 (200 C rated), and BMS 1360 (260 C rated). A second series of tests evaluated circuit breaker response to short circuits and ticking faults. These tests were also meant to determine if the three test wires behaved differently under these conditions and if a short circuit or ticking fault could start a fire. It is concluded that circuit breakers provided reliable overcurrent protection. Circuit breakers may not protect wire from ticking faults but can protect wire from direct shorts. These tests indicated that the appearance of a wire subjected to a current that totally degrades the insulation looks identical to a wire subjected to a fire; however the 'fire exposed' conductor was more brittle than the conductor degraded by overcurrent. Preliminary testing indicates that direct short circuits are not likely to start a fire. Preliminary testing indicated that direct short circuits do not erode insulation and conductor to the extent that ticking faults did. Circuit breakers may not safeguard against the ignition of flammable materials by ticking faults. The flammability of materials near ticking faults is far more important than the rating of the wire insulation material.

  18. Investigation of the dielectric recovery in synthetic air in a high voltage circuit breaker

    NASA Astrophysics Data System (ADS)

    Seeger, M.; Naidis, G.; Steffens, A.; Nordborg, H.; Claessens, M.

    2005-06-01

    The dielectric recovery of an axially blown arc in an experimental set-up based on a conventional HV circuit breaker was investigated both experimentally and theoretically. As a quenching gas, synthetic air was used. The investigated time range was from 10 µs to 10 ms after current zero (CZ). A fast rise in the dielectric strength during the first 100 µs, followed by a plateau and further rise later was observed. The dependences on the breaking current and pressure were determined. The measured dielectric recovery during the first 100 µs after CZ could be reproduced with good accuracy by computational fluid dynamics simulations. From that it could be deduced that the temperature decay in the axis does not depend sensitively on the pressure. The dielectric recovery during the first 100 µs scales therefore mainly with the filling pressure. The plateau in the breakdown characteristic is due to a hot vapour layer from the still evaporating PTFE nozzle surface.

  19. Hybrid Direct-Current Circuit Breaker

    NASA Technical Reports Server (NTRS)

    Wang, Ruxi (Inventor); Premerlani, William James (Inventor); Caiafa, Antonio (Inventor); Pan, Yan (Inventor)

    2017-01-01

    A circuit breaking system includes a first branch including at least one solid-state snubber; a second branch coupled in parallel to the first branch and including a superconductor and a cryogenic contactor coupled in series; and a controller operatively coupled to the at least one solid-state snubber and the cryogenic contactor and programmed to, when a fault occurs in the load circuit, activate the at least one solid-state snubber for migrating flow of the electrical current from the second branch to the first branch, and, when the fault is cleared in the load circuit, activate the cryogenic contactor for migrating the flow of the electrical current from the first branch to the second branch.

  20. Fiber-coupled LED gas sensor and its application to online monitoring of ecoefficient dielectric insulation gases in high-voltage circuit breakers.

    PubMed

    Kramer, Axel; Over, Daniel; Stoller, Patrick; Paul, Thomas A

    2017-05-20

    Novel dielectric insulation gases used as alternatives to sulfur hexafluoride in gas-insulated switchgear (GIS) include several mixtures containing fluorinated organic compounds. We developed a fiber-optic analyzer enabling concentration measurement of fluoroketones used in medium- and high-voltage switchgear applications by ABB, with concurrent compensation of disturbing effects caused by dust and dirt. The sensor enables measurements in GIS and even in operating high-voltage circuit breakers. The online availability of concentration readings of fluoroketones is important for development tests, but can also be applied for monitoring or diagnostics of field installations.

  1. Series resonance inverter with triggered vacuum gaps

    NASA Astrophysics Data System (ADS)

    Damstra, Geert C.; Zhang, X.

    1994-05-01

    Series resonance inverters based on semi-conductor switching elements are well-known and have a wide range of application, mainly for lower voltages. For high voltage application many switching elements have to be put in series to obtain sufficient blocking voltage. Voltage grinding and multiple gate control elements are needed. There is much experience with the triggered vacuum gaps as high voltage/high current single shot elements, for example in reignition circuits for synthetic circuit breaker tests. These elements have a blocking voltage of 50 - 100 kV and are triggerable by a light fiber control device. A prototype inverter has been developed that generates 0.1 Hz, 30 kV AC voltages with a flat top for tests on cables and capacitors of many micro farads fed from a low voltage supply of about 600 V. Only two TVG elements are needed to switch the resonant circuit alternatively on the positive or negative supply. The resonant circuit itself consists of the capacitance of the testobject and a high quality inductor that determines the frequency and the peak current of the voltage reversing process.

  2. 30 CFR 75.900 - Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Low- and medium-voltage circuits serving three... STANDARDS-UNDERGROUND COAL MINES Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900 Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit breakers...

  3. 30 CFR 75.900 - Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Low- and medium-voltage circuits serving three... STANDARDS-UNDERGROUND COAL MINES Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900 Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit breakers...

  4. 30 CFR 75.900 - Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Low- and medium-voltage circuits serving three... STANDARDS-UNDERGROUND COAL MINES Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900 Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit breakers...

  5. Power-Switching Circuit

    NASA Technical Reports Server (NTRS)

    Praver, Gerald A.; Theisinger, Peter C.; Genofsky, John

    1987-01-01

    Functions of circuit breakers, meters, and switches combined. Circuit that includes power field-effect transistors (PFET's) provides on/off switching, soft starting, current monitoring, current tripping, and protection against overcurrent for 30-Vdc power supply at normal load currents up to 2 A. Has no moving parts.

  6. On issue of reconstruction at central distribution substation by example of one of plants of Chelyabinsk region

    NASA Astrophysics Data System (ADS)

    Brylina, O. G.; Semenova, K. D.; Shashkin, V. YU

    2018-03-01

    The article considers the issues of increasing the reliability and economy of the distribution substation. The result is found due to the reconstruction of the central distribution substation and one of the plants of Chelyabinsk region. The reasons for the reconstruction are explained. A comparison of oil and vacuum circuit breakers is made. The advantages of vacuum circuit breakers are shown. Alternative replacement of cables is offered. The basic technical characteristics of the cable brands are shown. The results of reconstruction are proved.

  7. Multi-mode ultra-strong coupling (I): spectroscopic experiments using a vacuum-gap transmon circuit architecture

    NASA Astrophysics Data System (ADS)

    Bosman, Sal J.; Gely, Mario F.; Singh, Vibhor; Bruno, Alessandro; Bothner, Daniel; Steele, Gary A.

    In circuit QED, multi-mode extensions of the quantum Rabi model suffer from divergence problems. Here, we spectroscopically study multi-mode ultra-strong coupling using a transmon circuit architecture, which provides no clear guidelines on how many modes play a role in the dynamics of the system. As our transmon qubit, we employ a suspended island above the voltage anti-node of a λ / 4 coplanar microwave resonator, thereby realising a circuit where 88% of the qubit capacitance is formed by a vacuum-gap capacitor with the center conductor of the resonator. We measure vacuum Rabi splitting over multiple modes up to 2 GHz, reaching coupling ratios of g / ω = 0 . 18 , well within the ultra-strong coupling regime. We observe a qubit-mediated mode coupling, measurable up to the fifth mode at 38 GHz. Using a novel analytical quantum circuit model of this architecture, which includes all modes without introducing divergencies, we are able to fit the full spectrum and extract a vacuum fluctuations induced Bloch-Siegert shift of up to 62 MHz. This circuit architecture expands the versatility of the transmon technology platform and opens many possibilities in multi-mode physics in the ultra-strong coupling regime.

  8. 30 CFR 77.900 - Low- and medium-voltage circuits serving portable or mobile three-phase alternating current...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... portable or mobile three-phase alternating current equipment; circuit breakers. 77.900 Section 77.900... mobile three-phase alternating current equipment; circuit breakers. Low- and medium-voltage circuits supplying power to portable or mobile three-phase alternating current equipment shall be protected by...

  9. Optical diagnostics of the arc plasma using fast intensified CCD-spectrograph system

    NASA Astrophysics Data System (ADS)

    Pavelescu, Gabriela; Guillot, Stephane; Braic, Mariana T.; Hong, Dunpin; Pavelescu, D.; Fleurier, Claude; Braic, Viorel; Gherendi, F.; Dumitrescu, G.; Anghelita, P.; Bauchire, J. M.

    2004-10-01

    Spectroscopic diagnostics, using intensified high speed CCD camera, was applied to study the arc dynamics in low voltage circuit breakers, in vacuum and in air. Time-resolved emission spectroscopy of the vacuum arc plasma, generated during electrode separation, provided information about the interruption process. The investigations were focused on the partial unsuccessful interruption around current zero. Absorption spectroscopy, in a peculiar setup, was used in order to determine the metallic atoms densities in the interelectrode space of a low voltage circuit breaker, working in ambient air.

  10. 30 CFR 75.900-2 - Approved circuit schemes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... device installed in the main secondary circuit at the source transformer may be used to provide undervoltage protection for each circuit that receives power from that transformer. (c) One circuit breaker may...

  11. 30 CFR 75.900-2 - Approved circuit schemes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... device installed in the main secondary circuit at the source transformer may be used to provide undervoltage protection for each circuit that receives power from that transformer. (c) One circuit breaker may...

  12. 30 CFR 75.900-2 - Approved circuit schemes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... device installed in the main secondary circuit at the source transformer may be used to provide undervoltage protection for each circuit that receives power from that transformer. (c) One circuit breaker may...

  13. 30 CFR 75.900-2 - Approved circuit schemes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... device installed in the main secondary circuit at the source transformer may be used to provide undervoltage protection for each circuit that receives power from that transformer. (c) One circuit breaker may...

  14. 30 CFR 75.900-2 - Approved circuit schemes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... device installed in the main secondary circuit at the source transformer may be used to provide undervoltage protection for each circuit that receives power from that transformer. (c) One circuit breaker may...

  15. Compact self-powered synchronous energy extraction circuit design with enhanced performance

    NASA Astrophysics Data System (ADS)

    Liu, Weiqun; Zhao, Caiyou; Badel, Adrien; Formosa, Fabien; Zhu, Qiao; Hu, Guangdi

    2018-04-01

    Synchronous switching circuit is viewed as an effective solution of enhancing the generator’s performance and providing better adaptability for load variations. A critical issue for these synchronous switching circuits is the self-powered realization. In contrast with other methods, the electronic breaker possesses the advantage of simplicity and reliability. However, beside the energy consumption of the electronic breakers, the parasitic capacitance decreases the available piezoelectric voltage. In this technical note, a new compact design of the self-powered switching circuit using electronic breaker is proposed. The envelope diodes are excluded and only a single envelope capacitor is used. The parasitic capacitance is reduced to half with boosted performance while the components are reduced with cost saved.

  16. Speckle measurements of density and temperature profiles in a model gas circuit breaker

    NASA Astrophysics Data System (ADS)

    Stoller, P. C.; Panousis, E.; Carstensen, J.; Doiron, C. B.; Färber, R.

    2015-01-01

    Speckle imaging was used to measure the density and temperature distribution in the arc zone of a model high voltage circuit breaker during the high current phase and under conditions simulating those present during current-zero crossings (current-zero-like arc); the arc was stabilized by a transonic, axial flow of synthetic air. A single probe beam was used; thus, accurate reconstruction was only possible for axially symmetric gas flows and arc channels. The displacement of speckles with respect to a reference image was converted to a line-of-sight integrated deflection angle, which was in turn converted into an axially symmetric refractive index distribution using a multistep process that made use of the inverse Radon transform. The Gladstone-Dale relation, which gives the index of refraction as a function of density, was extended to high temperatures by taking into account dissociation and ionization processes. The temperature and density were determined uniquely by assuming that the pressure distribution in the case of cold gas flow (in the absence of an arc) is not modified significantly by the arc. The electric conductivity distribution was calculated from the temperature profile and compared to measurements of the arc voltage and to previous results published in the literature for similar experimental conditions.

  17. Investigation of DC hybrid circuit breaker based on high-speed switch and arc generator

    NASA Astrophysics Data System (ADS)

    Wu, Yifei; Rong, Mingzhe; Wu, Yi; Yang, Fei; Li, Mei; Zhong, Jianying; Han, Guohui; Niu, Chunping; Hu, Yang

    2015-02-01

    A new design of DC hybrid circuit breaker based on high-speed switch (HSS) and arc generator (AG), which can drastically profit from low heat loss in normal state and fast current breaking under fault state, is presented and analyzed in this paper. AG is designed according to the magnetic pinch effect of liquid metal. By utilizing the arc voltage generated across AG, the fault current is rapidly commutated from HSS into parallel connected branch. As a consequence, the arcless open of HSS is achieved. The post-arc conducting resume time (Δ tc) of AG and the commutation original voltage (Uc), two key factors in the commutation process, are investigated experimentally. Particularly, influences of the liquid metal channel diameter (Φ) of AG, fault current rate of rise (di/dt) and Uc on Δ tc are focused on. Furthermore, a suitable Uc is determined during the current commutation process, aiming at the reliable arcless open of HSS and short breaking time. Finally, the fault current breaking test is carried out for the current peak value of 11.8 kA, and the validity of the design is confirmed by the experimental results.

  18. Investigation of DC hybrid circuit breaker based on high-speed switch and arc generator.

    PubMed

    Wu, Yifei; Rong, Mingzhe; Wu, Yi; Yang, Fei; Li, Mei; Zhong, Jianying; Han, Guohui; Niu, Chunping; Hu, Yang

    2015-02-01

    A new design of DC hybrid circuit breaker based on high-speed switch (HSS) and arc generator (AG), which can drastically profit from low heat loss in normal state and fast current breaking under fault state, is presented and analyzed in this paper. AG is designed according to the magnetic pinch effect of liquid metal. By utilizing the arc voltage generated across AG, the fault current is rapidly commutated from HSS into parallel connected branch. As a consequence, the arcless open of HSS is achieved. The post-arc conducting resume time (Δ tc) of AG and the commutation original voltage (Uc), two key factors in the commutation process, are investigated experimentally. Particularly, influences of the liquid metal channel diameter (Φ) of AG, fault current rate of rise (di/dt) and Uc on Δ tc are focused on. Furthermore, a suitable Uc is determined during the current commutation process, aiming at the reliable arcless open of HSS and short breaking time. Finally, the fault current breaking test is carried out for the current peak value of 11.8 kA, and the validity of the design is confirmed by the experimental results.

  19. Method for sequentially processing a multi-level interconnect circuit in a vacuum chamber

    NASA Technical Reports Server (NTRS)

    Routh, D. E.; Sharma, G. C. (Inventor)

    1984-01-01

    An apparatus is disclosed which includes a vacuum system having a vacuum chamber in which wafers are processed on rotating turntables. The vacuum chamber is provided with an RF sputtering system and a dc magnetron sputtering system. A gas inlet introduces various gases to the vacuum chamber and creates various gas plasma during the sputtering steps. The rotating turntables insure that the respective wafers are present under the sputtering guns for an average amount of time such that consistency in sputtering and deposition is achieved. By continuous and sequential processing of the wafers in a common vacuum chamber without removal, the adverse affects of exposure to atmospheric conditions are eliminated providing higher quality circuit contacts and functional device.

  20. Method for sequentially processing a multi-level interconnect circuit in a vacuum chamber

    NASA Technical Reports Server (NTRS)

    Routh, D. E.; Sharma, G. C. (Inventor)

    1982-01-01

    The processing of wafer devices to form multilevel interconnects for microelectronic circuits is described. The method is directed to performing the sequential steps of etching the via, removing the photo resist pattern, back sputtering the entire wafer surface and depositing the next layer of interconnect material under common vacuum conditions without exposure to atmospheric conditions. Apparatus for performing the method includes a vacuum system having a vacuum chamber in which wafers are processed on rotating turntables. The vacuum chamber is provided with an RF sputtering system and a DC magnetron sputtering system. A gas inlet is provided in the chamber for the introduction of various gases to the vacuum chamber and the creation of various gas plasma during the sputtering steps.

  1. Simulation of switching overvoltages in the mine electric power supply system

    NASA Astrophysics Data System (ADS)

    Ivanchenko, D. I.; Novozhilov, N. G.

    2017-02-01

    Overvoltages occur in mine power supply systems during switching off consumers with high inductive load, such as transformers, reactors and electrical machines. Overvoltages lead to an increase of insulation degradation rate and may cause electric faults, power outage, fire and explosion of methane and coal dust. This paper is dedicated to simulation of vacuum circuit breaker switching overvoltages in a mine power supply system by means of Simulink MATLAB. The model of the vacuum circuit breaker implements simulation of transient recovery voltage, current chopping and an electric arc. Obtained results were compared to available experimental data.

  2. Recovery of materials from waste printed circuit boards by vacuum pyrolysis and vacuum centrifugal separation.

    PubMed

    Zhou, Yihui; Wu, Wenbiao; Qiu, Keqiang

    2010-11-01

    In this research, a two-step process consisting of vacuum pyrolysis and vacuum centrifugal separation was employed to treat waste printed circuit boards (WPCBs). Firstly, WPCBs were pyrolysed under vacuum condition at 600 °C for 30 min in a lab-scale reactor. Then, the obtained pyrolysis residue was heated under vacuum until the solder was melted, and then the molten solder was separated from the pyrolysis residue by the centrifugal force. The results of vacuum pyrolysis showed that the type-A of WPCBs (the base plates of which was made from cellulose paper reinforced phenolic resin) pyrolysed to form an average of 67.97 wt.% residue, 27.73 wt.% oil, and 4.30 wt.% gas; and pyrolysis of the type-B of WPCBs (the base plates of which was made from glass fiber reinforced epoxy resin) led to an average mass balance of 72.20 wt.% residue, 21.45 wt.% oil, and 6.35 wt.% gas. The results of vacuum centrifugal separation showed that the separation of solder was complete when the pyrolysis residue was heated at 400 °C, and the rotating drum was rotated at 1200 rpm for 10 min. The pyrolysis oil and gas can be used as fuel or chemical feedstock after treatment. The pyrolysis residue after solder separation contained various metals, glass fibers and other inorganic materials, which could be recycled for further processing. The recovered solder can be reused directly and it can also be a good resource of lead and tin for refining. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. 46 CFR 39.2011 - Vapor overpressure and vacuum protection-TB/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... freely and does not remain in the open position. (c) A liquid filled pressure-vacuum breaker may be used... 46 Shipping 1 2014-10-01 2014-10-01 false Vapor overpressure and vacuum protection-TB/ALL. 39.2011... Equipment and Installation § 39.2011 Vapor overpressure and vacuum protection—TB/ALL. (a) The cargo tank...

  4. 46 CFR 39.2011 - Vapor overpressure and vacuum protection-TB/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... freely and does not remain in the open position. (c) A liquid filled pressure-vacuum breaker may be used... 46 Shipping 1 2013-10-01 2013-10-01 false Vapor overpressure and vacuum protection-TB/ALL. 39.2011... Equipment and Installation § 39.2011 Vapor overpressure and vacuum protection—TB/ALL. (a) The cargo tank...

  5. Observation of copper atoms behavior in a vacuum arc discharge using laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Sung, Y. M.; Hayashi, Y.; Okraku-Yirenkyi, Y.; Otsubo, M.; Honda, C.; Sakoda, T.

    2003-01-01

    In order to investigate the most important parameters influencing the breaking characteristic of a vacuum circuit breaker (VCB), the behavior of copper (Cu) particles emitted from electrodes designed as an imitation of a vacuum valve of the VCB was observed. The temporal-spatial intensity distributions due to Cu particles in an excited state or a neutral state were measured using the laser induced fluorescence (LIF) technique and a charge coupled device camera attached with a special filter. The diffusion velocity of a Cu atom was also investigated by evaluating a Doppler shift of the LIF signal. The results showed that most Cu particles were emitted from the anode and were in an excited state or an ionized state during an arc discharge. Also, Cu particles were distributed between electrodes even after the discharge chocked, and its diffusion velocity in the direction of the cathode from the anode was about 2.6 km/s.

  6. Analysis of Arc Characteristics and Flow Field in Arc Chamber of High-Voltage SF6 Auto-Expansion Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Zhang, Junmin; Chen, Zhang

    2008-10-01

    A new magnetic hydro-dynamics model for nozzle arc emphasizing the interaction of arc with PTFE (polytetrafluorethylene) vapour is established based on the conservation equations. The interruption of auto-expansion circuit breaker is simulated numerically by finite element method and the influence of PTFE vapour on the arc is analysed with this model. The results reveal that the flow field inside the arc chamber is determined by the arc current, the arcing time, the nozzle arc and the clogging of its thermal boundary. The establishment of quenching pressure relies on both SF6 gas and PTFE vapour that absorbed arc energy in the nozzle. The PTFE vapour leads to an increase in the pressure of nozzle arc obviously, and a decrease in the temperature of arc. But it enhances the temperature of arc at zero current and slows down the decreasing rate of arc temperature as the current decreases.

  7. Calculation and Analysis of Dynamic Characteristics of Multilink Permanent Magnetic Actuator in Vacuum Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Liu, Yingyi; Yuan, Haiwen; Zhang, Qingjie; Chen, Degui; Yuan, Haibin

    The dynamic characteristics are the key issues in the optimum design of a permanent magnetic actuator (PMA). A new approach to forecast the dynamic characteristics of the multilink PMA is proposed. By carrying out further developments of ADAMS and ANSOFT, a mathematic calculation model describing the coupling of mechanical movement, electric circuit and magnetic field considering eddy current effect, is constructed. With this model, the dynamic characteristics of the multilink PMA are calculated and compared with the experimental results. Factors that affect the opening time of the multilink PMA are analyzed with the model as well. The method is capable of providing a reference for the design of the PMA.

  8. Rectifier cabinet static breaker

    DOEpatents

    Costantino, Jr, Roger A.; Gliebe, Ronald J.

    1992-09-01

    A rectifier cabinet static breaker replaces a blocking diode pair with an SCR and the installation of a power transistor in parallel with the latch contactor to commutate the SCR to the off state. The SCR serves as a static breaker with fast turnoff capability providing an alternative way of achieving reactor scram in addition to performing the function of the replaced blocking diodes. The control circuitry for the rectifier cabinet static breaker includes on-line test capability and an LED indicator light to denote successful test completion. Current limit circuitry provides high-speed protection in the event of overload.

  9. 14 CFR 25.1357 - Circuit protective devices.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... designed to de-energize and disconnect faulty power sources and power transmission equipment from their... malfunctioning. (c) Each resettable circuit protective device must be designed so that, when an overload or... must be designed so that circuit breakers are not the primary means to remove or reset system power...

  10. 14 CFR 25.1357 - Circuit protective devices.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... designed to de-energize and disconnect faulty power sources and power transmission equipment from their... malfunctioning. (c) Each resettable circuit protective device must be designed so that, when an overload or... must be designed so that circuit breakers are not the primary means to remove or reset system power...

  11. 14 CFR 25.1357 - Circuit protective devices.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... designed to de-energize and disconnect faulty power sources and power transmission equipment from their... malfunctioning. (c) Each resettable circuit protective device must be designed so that, when an overload or... must be designed so that circuit breakers are not the primary means to remove or reset system power...

  12. 14 CFR 25.1357 - Circuit protective devices.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... designed to de-energize and disconnect faulty power sources and power transmission equipment from their... malfunctioning. (c) Each resettable circuit protective device must be designed so that, when an overload or... must be designed so that circuit breakers are not the primary means to remove or reset system power...

  13. Discussion of Electrode Conditioning Mechanism Based on Pre-breakdown Current under Non-uniform Electric Field in Vacuum

    NASA Astrophysics Data System (ADS)

    Yasuoka, Takanori; Kato, Tomohiro; Kato, Katsumi; Okubo, Hitoshi

    Electrode conditioning is very important technique for improvement of the insulation performance of vacuum circuit breakers (VCBs). This paper discusses the spark conditioning mechanism under non-uniform electric field focused on the pre-breakdown current. We quantitatively evaluated the spark conditioning effect by analyzing the pre-breakdown current based on Fowler-Nordheim equation. As a result, field enhancement factor β decreased with the increasing in breakdown voltage in the beginning of conditioning process, and finally β was saturated with the saturation of breakdown voltage. In addition, in case of non-uniform field, we found that β on high voltage rod electrode after conditioning varied according to the electric field strength on the rod electrode.

  14. Overview spectra and axial distribution of spectral line intensities in a high-current vacuum arc with CuCr electrodes

    NASA Astrophysics Data System (ADS)

    Lisnyak, M.; Pipa, A. V.; Gorchakov, S.; Iseni, S.; Franke, St.; Khapour, A.; Methling, R.; Weltmann, K.-D.

    2015-09-01

    Spectroscopic investigations of free-burning vacuum arcs in diffuse mode with CuCr electrodes are presented. The experimental conditions of the investigated arc correspond to the typical system for vacuum circuit breakers. Spectra of six species Cu I, Cu II, Cu III, Cr I, Cr II, and Cr III have been analyzed in the wavelength range 350-810 nm. The axial intensity distributions were found to be strongly dependent on the ionization stage of radiating species. Emission distributions of Cr II and Cu II can be distinguished as well as the distributions of Cr III and Cu III. Information on the axial distribution was used to identify the spectra and for identification of overlapping spectral lines. The overview spectra and some spectral windows recorded with high resolution are presented. Analysis of axial distributions of emitted light, which originates from different ionization states, is presented and discussed.

  15. 30 CFR 75.800-2 - Approved circuit schemes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... necessary protection to the circuits required by § 75.800: (a) Ground check relays may be used for undervoltage protection if the relay coils are designed to trip the circuit breaker when line voltage decreases to 40 percent to 60 percent of the nominal line voltage; (b) Ground trip relays on resistance...

  16. 30 CFR 75.800-2 - Approved circuit schemes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... necessary protection to the circuits required by § 75.800: (a) Ground check relays may be used for undervoltage protection if the relay coils are designed to trip the circuit breaker when line voltage decreases to 40 percent to 60 percent of the nominal line voltage; (b) Ground trip relays on resistance...

  17. Development and testing of a 180-volt dc electronic circuit breaker with a 335-ampere carry and 1200-ampere interrupt rating

    NASA Technical Reports Server (NTRS)

    Brush, A. S.; Phillips, R. L.

    1991-01-01

    NASA Lewis Research Center and associated contractors have conducted a program to assess the potential requirements for a high-current switch to conceptually design a switch using the best existing technology, and to build and demonstrate a breadboard which meets the requirements. The result is the high current remote bus isolator (HRBI). The HRBI is rated at 180 V dc, 335 A continuous with a 1200 A interrupt rating. It also incorporates remote-control and protective features called for by the Space Station Freedom PMAD dc test bed design. Two breadboard 335 A circuit breakers were built and tested that demonstrate a promising concept of paralleled current-limiting modules. The units incorporated all control and protective features required by advanced aerospace power systems. Component stresses in each unit were determined by design, and are consistent with a life of many thousands of fault operations.

  18. 30 CFR 77.900 - Low- and medium-voltage circuits serving portable or mobile three-phase alternating current...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Low- and medium-voltage circuits serving... Medium-Voltage Alternating Current Circuits § 77.900 Low- and medium-voltage circuits serving portable or mobile three-phase alternating current equipment; circuit breakers. Low- and medium-voltage circuits...

  19. 30 CFR 77.900 - Low- and medium-voltage circuits serving portable or mobile three-phase alternating current...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Low- and medium-voltage circuits serving... Medium-Voltage Alternating Current Circuits § 77.900 Low- and medium-voltage circuits serving portable or mobile three-phase alternating current equipment; circuit breakers. Low- and medium-voltage circuits...

  20. 30 CFR 77.900 - Low- and medium-voltage circuits serving portable or mobile three-phase alternating current...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Low- and medium-voltage circuits serving... Medium-Voltage Alternating Current Circuits § 77.900 Low- and medium-voltage circuits serving portable or mobile three-phase alternating current equipment; circuit breakers. Low- and medium-voltage circuits...

  1. Overview spectra and axial distribution of spectral line intensities in a high-current vacuum arc with CuCr electrodes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lisnyak, M.; Pipa, A. V.; Gorchakov, S., E-mail: gorchakov@inp-greifswald.de, E-mail: weltmann@inp-greifswald.de

    2015-09-28

    Spectroscopic investigations of free-burning vacuum arcs in diffuse mode with CuCr electrodes are presented. The experimental conditions of the investigated arc correspond to the typical system for vacuum circuit breakers. Spectra of six species Cu I, Cu II, Cu III, Cr I, Cr II, and Cr III have been analyzed in the wavelength range 350–810 nm. The axial intensity distributions were found to be strongly dependent on the ionization stage of radiating species. Emission distributions of Cr II and Cu II can be distinguished as well as the distributions of Cr III and Cu III. Information on the axial distribution wasmore » used to identify the spectra and for identification of overlapping spectral lines. The overview spectra and some spectral windows recorded with high resolution are presented. Analysis of axial distributions of emitted light, which originates from different ionization states, is presented and discussed.« less

  2. 46 CFR 28.365 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... (c) Each ungrounded current carrying conductor must be protected in accordance with its current carrying capacity by a circuit breaker or fuse at the connection to the switchboard or distribution panel...

  3. Insulation Technology in Dry Air and Vacuum for a 72kV Low Pressured Dry Air Insulated Switchgear

    NASA Astrophysics Data System (ADS)

    Yoshida, Tadahiro; Koga, Hiromi; Harada, Takakazu; Miki, Shinichi; Arioka, Masahiro; Sato, Shinji; Yoshida, Satoru; Inoue, Naoaki; Maruyama, Akihiko; Takeuchi, Toshie

    A new 72kV rated low pressured dry air insulated switchgear applying electromagnetic actuation and function that supports CBM has been developed. First, dielectric characteristics in dry air under lightning impulse application has been investigated at bare and insulator covered electrodes. Dependence of the breakdown electric field strength on the effective area has been clarified to apply the configuration design of the insulation mold for the vacuum interrupter. In addition, moisture volume dependence on surface resistance has been clarified to decide moisture volume in gas pressure tank. Next, a new vacuum circuit breaker (VCB) has been designed. To keep dimensions from former 72kV SF6 gas insulated switchgear, distance between contacts in vacuum interrupter is needed to be shorter than that of former switchgear. Voltage withstand capability between electrodes practically designed for vacuum interrupter has been investigated under dc voltage application simulated the small capacitive current breaking test. Gap configuration including contacts and slits has been optimized and distance has been shortened 11% from former switchgear. As a result, the new low pressured dry air insulated switchgear has been designed comparably in outer size to former SF6 gas insulated switchgear. Using dry air as an insulation medium with low pressure has been able to reduce the environmental burden.

  4. 46 CFR 111.105-31 - Flammable or combustible cargo with a flashpoint below 60 °C (140 °F), carriers of liquid-sulphur...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... be a lockable circuit breaker or lockable switch that disconnects power to the motor. (e) Cargo Tanks.../vacuum valves with an unlimited height; or (4) Within 10 meters (33 ft) of vent outlets for free flow of...

  5. 46 CFR 111.105-31 - Flammable or combustible cargo with a flashpoint below 60 °C (140 °F), carriers of liquid-sulphur...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... be a lockable circuit breaker or lockable switch that disconnects power to the motor. (e) Cargo Tanks.../vacuum valves with an unlimited height; or (4) Within 10 meters (33 ft) of vent outlets for free flow of...

  6. 46 CFR 111.105-31 - Flammable or combustible cargo with a flashpoint below 60 °C (140 °F), carriers of liquid-sulphur...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... be a lockable circuit breaker or lockable switch that disconnects power to the motor. (e) Cargo Tanks.../vacuum valves with an unlimited height; or (4) Within 10 meters (33 ft) of vent outlets for free flow of...

  7. Basic Radio Circuits and Vacuum Tube AM Troubleshooting; Radio and Television Service, Intermediate: 9785.03.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    The 135-hour quinmester course covers study of basic radio circuits as applied to vacuum tube radios in six blocks of instruction: orientation; AM receivers with tubes; no signal, audio failure; distortion; weak, noisy signals; and a post-test. Each block is subdivided into several units, and block objectives are outlined. Completion of AC…

  8. 1. View looking Northeast of Huber Breaker (left), Retail Coal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. View looking Northeast of Huber Breaker (left), Retail Coal Storage Bins (center), and Power Station (right foreground) Photograph taken by George Harven - Huber Coal Breaker, Breaker, 101 South Main Street, Ashley, Luzerne County, PA

  9. The new technological solution for the JT-60SA quench protection circuits

    NASA Astrophysics Data System (ADS)

    Gaio, E.; Maistrello, A.; Novello, L.; Matsukawa, M.; Perna, M.; Ferro, A.; Yamauchi, K.; Piovan, R.

    2018-07-01

    An advanced technology has been developed and employed for the main circuit breakers (CB) of the quench protection circuits (QPC) of the superconducting coils of JT-60SA: it consists in a Hybrid mechanical-static CB (HCB) composed of a mechanical Bypass switch (BPS) for conducting the continuous current, in parallel to a static circuit breaker (SCB) based on integrated gate commutated thyristor (IGCT) for current interruption. It was the result of a R&D program carried out since 2006 to identify innovative solutions for the interruption of high dc current, able to improve the maintainability and availability of the CB. The HCB developed for the JT-60SA QPC is the first realization of a dc circuit breaker based on this design approach for interrupting current of some tens of kA with reapplied voltage of some kV. It also represents the first application of hybrid technology with IGCT for protection of superconducting magnets in fusion experiments. The paper aims at giving a comprehensive overview of the main R&D activities devoted to the development of this new technological approach; then, the key aspects of the design, manufacturing and testing of the QPCs for JT-60SA, successfully completed in Naka Site in summer 2015 are presented. Finally, the significance of this research is discussed and the possible future developments, in particular in view of DEMO fusion reactor, are outlined.

  10. Vision based speed breaker detection for autonomous vehicle

    NASA Astrophysics Data System (ADS)

    C. S., Arvind; Mishra, Ritesh; Vishal, Kumar; Gundimeda, Venugopal

    2018-04-01

    In this paper, we are presenting a robust and real-time, vision-based approach to detect speed breaker in urban environments for autonomous vehicle. Our method is designed to detect the speed breaker using visual inputs obtained from a camera mounted on top of a vehicle. The method performs inverse perspective mapping to generate top view of the road and segment out region of interest based on difference of Gaussian and median filter images. Furthermore, the algorithm performs RANSAC line fitting to identify the possible speed breaker candidate region. This initial guessed region via RANSAC, is validated using support vector machine. Our algorithm can detect different categories of speed breakers on cement, asphalt and interlock roads at various conditions and have achieved a recall of 0.98.

  11. Shotgun cartridge rock breaker

    DOEpatents

    Ruzzi, Peter L.; Morrell, Roger J.

    1995-01-01

    A rock breaker uses shotgun cartridges or other firearm ammunition as the explosive charge at the bottom of a drilled borehole. The breaker includes a heavy steel rod or bar, a gun with a firing chamber for the ammunition which screws onto the rod, a long firing pin running through a central passage in the rod, and a firing trigger mechanism at the external end of the bar which strikes the firing pin to fire the cartridge within the borehole. A tubular sleeve surround the main body of the rod and includes slits the end to allow it to expand. The rod has a conical taper at the internal end against which the end of the sleeve expands when the sleeve is forced along the rod toward the taper by a nut threaded onto the external end of the rod. As the sleeve end expands, it pushes against the borehole and holds the explosive gasses within, and also prevents the breaker from flying out of the borehole. The trigger mechanism includes a hammer with a slot and a hole for accepting a drawbar or drawpin which, when pulled by a long cord, allows the cartridge to be fired from a remote location.

  12. GATING CIRCUITS

    DOEpatents

    Merrill, L.C.

    1958-10-14

    Control circuits for vacuum tubes are described, and a binary counter having an improved trigger circuit is reported. The salient feature of the binary counter is the application of the input signal to the cathode of each of two vacuum tubes through separate capacitors and the connection of each cathode to ground through separate diodes. The control of the binary counter is achieved in this manner without special pulse shaping of the input signal. A further advantage of the circuit is the simplicity and minimum nuruber of components required, making its use particularly desirable in computer machines.

  13. Using vacuum pyrolysis and mechanical processing for recycling waste printed circuit boards.

    PubMed

    Long, Laishou; Sun, Shuiyu; Zhong, Sheng; Dai, Wencan; Liu, Jingyong; Song, Weifeng

    2010-05-15

    The constant growth in generation of waste printed circuit boards (WPCB) poses a huge disposal problem because they consist of a heterogeneous mixture of organic and metallic chemicals as well as glass fiber. Also the presence of heavy metals, such as Pb and Cd turns this scrap into hazardous waste. Therefore, recycling of WPCB is an important subject not only from the recovery of valuable materials but also from the treatment of waste. The aim of this study was to present a recycling process without negative impact to the environment as an alternative for recycling WPCB. In this work, a process technology containing vacuum pyrolysis and mechanical processing was employed to recycle WPCB. At the first stage of this work, the WPCB was pyrolyzed under vacuum in a self-made batch pilot-scale fixed bed reactor to recycle organic resins contained in the WPCB. By vacuum pyrolysis the organic matter was decomposed to gases and liquids which could be used as fuels or chemical material resources, however, the inorganic WPCB matter was left unaltered as solid residues. At the second stage, the residues obtained at the first stage were investigated to separate and recover the copper through mechanical processing such as crushing, screening, and gravity separation. The copper grade of 99.50% with recovery of 99.86% based on the whole WPCB was obtained. And the glass fiber could be obtained by calcinations in a muffle furnace at 600 degrees C for 10 min. This study had demonstrated the feasibility of vacuum pyrolysis and mechanical processing for recycling WPCB. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  14. CIRCUITS FOR CURRENT MEASUREMENTS

    DOEpatents

    Cox, R.J.

    1958-11-01

    Circuits are presented for measurement of a logarithmic scale of current flowing in a high impedance. In one form of the invention the disclosed circuit is in combination with an ionization chamber to measure lonization current. The particular circuit arrangement lncludes a vacuum tube having at least one grid, an ionization chamber connected in series with a high voltage source and the grid of the vacuum tube, and a d-c amplifier feedback circuit. As the ionization chamber current passes between the grid and cathode of the tube, the feedback circuit acts to stabilize the anode current, and the feedback voltage is a measure of the logaritbm of the ionization current.

  15. Case study on impact performance optimization of hydraulic breakers.

    PubMed

    Noh, Dae-Kyung; Kang, Young-Ky; Cho, Jae-Sang; Jang, Joo-Sup

    2016-01-01

    In order to expand the range of activities of an excavator, attachments, such as hydraulic breakers have been developed to be applied to buckets. However, it is very difficult to predict the dynamic behavior of hydraulic impact devices such as breakers because of high non-linearity. Thus, the purpose of this study is to optimize the impact performance of hydraulic breakers. The ultimate goal of the optimization is to increase the impact energy and impact frequency and to reduce the pressure pulsation of the supply and return lines. The optimization results indicated that the four parameters used to optimize the impact performance of the breaker showed considerable improvement over the results reported in the literature. A test was also conducted and the results were compared with those obtained through optimization in order to verify the optimization results. The comparison showed an average relative error of 8.24 %, which seems to be in good agreement. The results of this study can be used to optimize the impact performance of hydraulic impact devices such as breakers, thus facilitating its application to excavators and increasing the range of activities of an excavator.

  16. 32. INTERIOR VIEW LOOKING NORTH ON THE ORE BREAKER LEVEL. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. INTERIOR VIEW LOOKING NORTH ON THE ORE BREAKER LEVEL. THE ORE BREAKER, A BLAKE JAW CRUSHER, IS IN THE BOX IN THE LEFT OF THE PHOTOGRAPH, THE ORE TO BE BROKEN IS FED INTO THE OPENING ON THE FLOOR AND NEXT TO ORE BREAKER BOX. THE GRIZZLY BARS ARE ON THE RIGHT AND THE PULLEYS FROM THE POWER SYSTEM ARE OVERHEAD. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  17. 28. View looking Northeast, Huber Breaker (left), Retail Coal Storage ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. View looking Northeast, Huber Breaker (left), Retail Coal Storage Bins (Center) Power Plant (right) Photograph taken by George Harven - Huber Coal Breaker, 101 South Main Street, Ashley, Luzerne County, PA

  18. 30. Looking to Huber Breaker (left), Retail Coal Storage Bins ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Looking to Huber Breaker (left), Retail Coal Storage Bins (center), and Power Plant (right) Photograph taken by George Harven - Huber Coal Breaker, 101 South Main Street, Ashley, Luzerne County, PA

  19. 44. Blue Coal Corporation Office Building (foreground), Huber Breaker (left), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Blue Coal Corporation Office Building (foreground), Huber Breaker (left), Retail Coal Storage Bins (far center) Photograph taken by George Harven - Huber Coal Breaker, 101 South Main Street, Ashley, Luzerne County, PA

  20. 31. Panoramic shot, Huber Breaker (left), Retail Coal Storage Bins ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. Panoramic shot, Huber Breaker (left), Retail Coal Storage Bins (center), Boney Elevator (right) Photographs taken by Joseph E.B. Elliot - Huber Coal Breaker, 101 South Main Street, Ashley, Luzerne County, PA

  1. Detail of motor control cabinet and field breakers. Control cabinet ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of motor control cabinet and field breakers. Control cabinet and breaker panel built by Cutler-Hammer - Wellton-Mohawk Irrigation System, Pumping Plant No. 3, South of Interstate 8, Wellton, Yuma County, AZ

  2. 29. Another view looking Northeast closer to Huber Breaker (left), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. Another view looking Northeast closer to Huber Breaker (left), Retail Coal Storage Bins (Center), Power Plant (right) Photograph taken by George Harven - Huber Coal Breaker, 101 South Main Street, Ashley, Luzerne County, PA

  3. Performance of bulk oil circuit breaker (BOCB) influenced by its parameters (Case study at the substation of Bogor Baru)

    NASA Astrophysics Data System (ADS)

    Goeritno, Arief; Rasiman, Syofyan

    2017-06-01

    Performance examination of the bulk oil circuit breaker that is influenced by its parameters at the Substation of Bogor Baru (the State Electricity Company = PLN) has been done. It is found that (1) dielectric strength of oil still qualifies as an insulating and cooling medium, because the average value of the measurement result is still above the minimum value allowed, where the minimum limit of 80 kV/2.5 cm or 32 kV/cm; (2) the simultaneity of the CB's contacts is still eligible, so that the BOCB can still be operated, because the difference of time between the highest and lowest values when the BOCB's contacts are opened/closed are less than (Δt<) 10 milliseconds (if meeting the PLN standards as recommended by Alsthom); and (3) the parameter of resistance according to the standards, where (i) the resistance of insulation has a value far above the allowed threshold, while the minimum standards are above 2,000 Mn (if meeting the ANSI standards) or on the value of 2,000 MΩ (if meeting PLN standards), (ii) the resistance of contacts has a value far above the allowed threshold, while the minimum standards are below 350 µΩ (if meeting ANSI standards) or on the value of 200 µΩ (if meeting PLN standards). The resistance of grounding is equal to the maximum limit specified, while the maximum standard is on the value of 0.5 Ω (if meeting PLN standard).

  4. 1. VIEW OF EAST FRONT OF BREAKER, WITH SCALE STICK, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW OF EAST FRONT OF BREAKER, WITH SCALE STICK, SHOWING FOUNDATIONS OF RETAIL SCALES IN FOREGROUND, LOOKING WEST - Marvine Colliery, Breaker No. 2, West side Boulevard Avenue, between East Parker Street & Route 380, Scranton, Lackawanna County, PA

  5. Workers' exposure to electric fields during the task 'maintenance of an operating device of circuit breaker from a service platform' at 110-kV substations.

    PubMed

    Korpinen, Leena; Pääkkönen, Rauno

    2018-02-26

    The objective of the study was to investigate occupational exposure to electric fields during the task 'maintenance of an operating device of circuit breaker from a service platform' at 110-kV substations. The aim was also to compare the results to Directive 2013/35/EU. At 16 substations, 255 electric field measurements were performed. The highest mean value of the electric fields was 9.6 kV⋅m -1 . At 63% of substations the maximum values were over 10.0 kV⋅m -1 , and at 31% of the substations the 75th percentiles were over 10.0 kV⋅m -1 , which is the low action level (AL) according to Directive 2013/35/EU. All measured values were below the high AL (20.0 kV⋅m -1 ). In the future, it is important to take into account that the measurements were only taken at Finnish 110-kV substations; therefore, it is not possible to generalize these results to other countries and different types of substations.

  6. Breaker zone aerosol dynamics in the southern Baltic Sea

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zielinski, T.; Zielinski, A.

    This paper presents the results of lidar based investigations of aerosol concentrations and their size distributions over the breaker zones. The measurements were carried out under various weather conditions over breaker zones of the Gulf of Gdansk (1992) and from a station on the open Baltic Sea (International Experiment BAEX in 1993).

  7. Detail of field breakers in the motor control cabinet for ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of field breakers in the motor control cabinet for unit 3. Control cabinet and breaker panel built by Cutler-Hammer - Wellton-Mohawk Irrigation System, Pumping Plant No. 1, Bounded by Gila River & Union Pacific Railroad, Wellton, Yuma County, AZ

  8. 47. Northwest Side of Breaker, Rock Belt Line (foreground), date ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. Northwest Side of Breaker, Rock Belt Line (foreground), date unknown Historic Photograph, Photograher Unknown; Collection of William Everett, Jr. (Wilkes-Barre, PA), photocopy by Joseph E.B. Elliot - Huber Coal Breaker, 101 South Main Street, Ashley, Luzerne County, PA

  9. Design and optimization of LCL-VSC grid-tied converter having short circuit fault current limiting ability

    NASA Astrophysics Data System (ADS)

    Liu, Mengqi; Liu, Haijun; Wang, Zhikai

    2017-01-01

    Traditional LCL grid-tied converters haven't the ability to limit the short-circuit fault current and only remove grid-connected converter using the breaker. However, the VSC converters become uncontrollable after the short circuit fault cutting off and the power switches may be damaged if the circuit breaker removes slowly. Compared to the filter function of the LCL passive components in traditional VSC converters, the novel LCL-VSC converter has the ability of limiting the short circuit fault current using the reasonable designed LCL parameters. In this paper the mathematical model of the LCL converter is established and the characteristics of the short circuit fault current generated by the ac side and dc side are analyzed. Thus one design and optimization scheme of the reasonable LCL passive parameter is proposed for the LCL-VSC converter having short circuit fault current limiting ability. In addition to ensuring the LCL passive components filtering the high-frequency harmonic, this scheme also considers the impedance characteristics to limit the fault current of AC and DC short circuit fault respectively flowing through the power switch no more than the maximum allowable operating current, in order to make the LCL converter working continuously. Finally, the 200kW simulation system is set up to prove the validity and feasibility of the theoretical analysis using the proposed design and optimization scheme.

  10. Mechanical Fault Diagnosis of High Voltage Circuit Breakers Based on Variational Mode Decomposition and Multi-Layer Classifier.

    PubMed

    Huang, Nantian; Chen, Huaijin; Cai, Guowei; Fang, Lihua; Wang, Yuqiang

    2016-11-10

    Mechanical fault diagnosis of high-voltage circuit breakers (HVCBs) based on vibration signal analysis is one of the most significant issues in improving the reliability and reducing the outage cost for power systems. The limitation of training samples and types of machine faults in HVCBs causes the existing mechanical fault diagnostic methods to recognize new types of machine faults easily without training samples as either a normal condition or a wrong fault type. A new mechanical fault diagnosis method for HVCBs based on variational mode decomposition (VMD) and multi-layer classifier (MLC) is proposed to improve the accuracy of fault diagnosis. First, HVCB vibration signals during operation are measured using an acceleration sensor. Second, a VMD algorithm is used to decompose the vibration signals into several intrinsic mode functions (IMFs). The IMF matrix is divided into submatrices to compute the local singular values (LSV). The maximum singular values of each submatrix are selected as the feature vectors for fault diagnosis. Finally, a MLC composed of two one-class support vector machines (OCSVMs) and a support vector machine (SVM) is constructed to identify the fault type. Two layers of independent OCSVM are adopted to distinguish normal or fault conditions with known or unknown fault types, respectively. On this basis, SVM recognizes the specific fault type. Real diagnostic experiments are conducted with a real SF₆ HVCB with normal and fault states. Three different faults (i.e., jam fault of the iron core, looseness of the base screw, and poor lubrication of the connecting lever) are simulated in a field experiment on a real HVCB to test the feasibility of the proposed method. Results show that the classification accuracy of the new method is superior to other traditional methods.

  11. Mechanical Fault Diagnosis of High Voltage Circuit Breakers Based on Variational Mode Decomposition and Multi-Layer Classifier

    PubMed Central

    Huang, Nantian; Chen, Huaijin; Cai, Guowei; Fang, Lihua; Wang, Yuqiang

    2016-01-01

    Mechanical fault diagnosis of high-voltage circuit breakers (HVCBs) based on vibration signal analysis is one of the most significant issues in improving the reliability and reducing the outage cost for power systems. The limitation of training samples and types of machine faults in HVCBs causes the existing mechanical fault diagnostic methods to recognize new types of machine faults easily without training samples as either a normal condition or a wrong fault type. A new mechanical fault diagnosis method for HVCBs based on variational mode decomposition (VMD) and multi-layer classifier (MLC) is proposed to improve the accuracy of fault diagnosis. First, HVCB vibration signals during operation are measured using an acceleration sensor. Second, a VMD algorithm is used to decompose the vibration signals into several intrinsic mode functions (IMFs). The IMF matrix is divided into submatrices to compute the local singular values (LSV). The maximum singular values of each submatrix are selected as the feature vectors for fault diagnosis. Finally, a MLC composed of two one-class support vector machines (OCSVMs) and a support vector machine (SVM) is constructed to identify the fault type. Two layers of independent OCSVM are adopted to distinguish normal or fault conditions with known or unknown fault types, respectively. On this basis, SVM recognizes the specific fault type. Real diagnostic experiments are conducted with a real SF6 HVCB with normal and fault states. Three different faults (i.e., jam fault of the iron core, looseness of the base screw, and poor lubrication of the connecting lever) are simulated in a field experiment on a real HVCB to test the feasibility of the proposed method. Results show that the classification accuracy of the new method is superior to other traditional methods. PMID:27834902

  12. Highly sensitive vacuum ion pump current measurement system

    DOEpatents

    Hansknecht, John Christopher [Williamsburg, VA

    2006-02-21

    A vacuum system comprising: 1) an ion pump; 2) power supply; 3) a high voltage DC--DC converter drawing power from the power supply and powering the vacuum pump; 4) a feedback network comprising an ammeter circuit including an operational amplifier and a series of relay controlled scaling resistors of different resistance for detecting circuit feedback; 5) an optional power block section intermediate the power supply and the high voltage DC--DC converter; and 6) a microprocessor receiving feedback information from the feedback network, controlling which of the scaling resistors should be in the circuit and manipulating data from the feedback network to provide accurate vacuum measurement to an operator.

  13. 51. South side of Breaker, Retail Pockets under Construction Historic ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. South side of Breaker, Retail Pockets under Construction Historic Photograph, Photographer Unknown Originally taken by Glen Alden Safety Department, 18 August 1954; Collection of William Everett, Jr. (Wilkes-Barre, PA), photocopy by Joseph E.B. Elliot - Huber Coal Breaker, 101 South Main Street, Ashley, Luzerne County, PA

  14. Statins: antimicrobial resistance breakers or makers?

    PubMed Central

    Lareu, Ricky R.; Dix, Brett R.; Hughes, Jeffery D.

    2017-01-01

    Introduction The repurposing of non-antibiotic drugs as adjuvant antibiotics may help break antimicrobial resistance (AMR). Statins are commonly prescribed worldwide to lower cholesterol. They also possess qualities of AMR “breakers”, namely direct antibacterial activity, synergism with antibiotics, and ability to stimulate the host immune system. However, statins’ role as AMR breakers may be limited. Their current extensive use for cardiovascular protection might result in selective pressures for resistance, ironically causing statins to be AMR “makers” instead. This review examines statins’ potential as AMR breakers, probable AMR makers, and identifies knowledge gaps in a statin-bacteria-human-environment continuum. The most suitable statin for repurposing is identified, and a mechanism of antibacterial action is postulated based on structure-activity relationship analysis. Methods A literature search using keywords “statin” or “statins” combined with “minimum inhibitory concentration” (MIC) was performed in six databases on 7th April 2017. After screening 793 abstracts, 16 relevant studies were identified. Unrelated studies on drug interactions; antifungal or antiviral properties of statins; and antibacterial properties of mevastatin, cerivastatin, antibiotics, or natural products were excluded. Studies involving only statins currently registered for human use were included. Results Against Gram-positive bacteria, simvastatin generally exerted the greatest antibacterial activity (lowest MIC) compared to atorvastatin, rosuvastatin, and fluvastatin. Against Gram-negative bacteria, atorvastatin generally exhibited similar or slightly better activity compared to simvastatin, but both were more potent than rosuvastatin and fluvastatin. Discussion Statins may serve as AMR breakers by working synergistically with existing topical antibiotics, attenuating virulence factors, boosting human immunity, or aiding in wound healing. It is probable that

  15. Liquid detection circuit

    DOEpatents

    Regan, Thomas O.

    1987-01-01

    Herein is a circuit which is capable of detecting the presence of liquids, especially cryogenic liquids, and whose sensor will not overheat in a vacuum. The circuit parameters, however, can be adjusted to work with any liquid over a wide range of temperatures.

  16. 30 CFR 75.900-3 - Testing, examination, and maintenance of circuit breakers; procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... current circuits serving three-phase alternating current equipment and their auxiliary devices shall be... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900-3 Testing, examination, and...

  17. 30 CFR 77.900-1 - Testing, examination, and maintenance of circuit breakers; procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... protecting low- and medium-voltage circuits serving portable or mobile three-phase alternating current... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits...

  18. 30 CFR 77.900-1 - Testing, examination, and maintenance of circuit breakers; procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... protecting low- and medium-voltage circuits serving portable or mobile three-phase alternating current... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits...

  19. 30 CFR 75.900-3 - Testing, examination, and maintenance of circuit breakers; procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... current circuits serving three-phase alternating current equipment and their auxiliary devices shall be... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900-3 Testing, examination, and...

  20. 30 CFR 77.900-2 - Testing, examination, and maintenance of circuit breakers; record.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... protecting low- and medium-voltage circuits serving three-phase alternating current equipment and such record... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits...

  1. 30 CFR 77.900-2 - Testing, examination, and maintenance of circuit breakers; record.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... protecting low- and medium-voltage circuits serving three-phase alternating current equipment and such record... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits...

  2. 30 CFR 75.900-4 - Testing, examination, and maintenance of circuit breakers; record.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... circuits serving three-phase alternating current equipment used in the mine. Such record shall be kept in a... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900-4 Testing, examination, and...

  3. 30 CFR 75.900-4 - Testing, examination, and maintenance of circuit breakers; record.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... circuits serving three-phase alternating current equipment used in the mine. Such record shall be kept in a... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900-4 Testing, examination, and...

  4. Removing lead from metallic mixture of waste printed circuit boards by vacuum distillation: factorial design and removal mechanism.

    PubMed

    Li, Xingang; Gao, Yujie; Ding, Hui

    2013-10-01

    The lead removal from the metallic mixture of waste printed circuit boards by vacuum distillation was optimized using experimental design, and a mathematical model was established to elucidate the removal mechanism. The variables studied in lead evaporation consisted of the chamber pressure, heating temperature, heating time, particle size and initial mass. The low-level chamber pressure was fixed at 0.1 Pa as the operation pressure. The application of two-level factorial design generated a first-order polynomial that agreed well with the data for evaporation efficiency of lead. The heating temperature and heating time exhibited significant effects on the efficiency, which was validated by means of the copper-lead mixture experiments. The optimized operating conditions within the region studied were the chamber pressure of 0.1 Pa, heating temperature of 1023 K and heating time of 120 min. After the conditions were employed to remove lead from the metallic mixture of waste printed circuit boards, the efficiency was 99.97%. The mechanism of the effects was elucidated by mathematical modeling that deals with evaporation, mass transfer and condensation, and can be applied to a wider range of metal removal by vacuum distillation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. The Effects of Wind and Surfactants on Mechanically Generated Spilling Breakers

    NASA Astrophysics Data System (ADS)

    Liu, X.; Diorio, J. D.; Duncan, J. H.

    2007-11-01

    The effects of both wind and surfactants on mechanically generated weakly spilling breakers are explored in a wind wave tank that is 11.8 m long, 1.15 m wide and 1.8 m high (1.0 m of water). A wave maker, which resides at the upwind end of the tank, is used to generate the breakers via a dispersive focusing method with a central wave packet frequency of 1.15 Hz. Low wind speeds (less than 3.0 m/s) are used to minimize the effect of short-wavelength wind-generated waves on the breakers. The profiles of the spilling breakers along the center plane of the tank are measured with an LIF technique that utilizes a high-speed digital movie camera. Measurements are performed with clean water and water mixed with various concentrations of Triton X-100, a soluble surfactant. It is found that the capillary waves/bulge patterns found in the initial stages of spilling breakers are dramatically affected by wind and surfactants. The size of bulge increases with the wind speed while the capillary waves are kept nearly the same. In the presence of surfactants and wind, both the amplitude and number of capillary waves are reduced and the slope of the front face of the wave increases.

  6. [Usefullness of the StoneBreaker lithotripter for percutaneous nephrolithotomy].

    PubMed

    del Peso, Almudena Coloma; González, Inmaculada Fernández; Gálvez, Milagros Jiménez; Abad, Pablo Garrido; Fajardo, Gloria Bocardo; Fernández, Luis Miguel Herranz; Arjona, Manuel Fernández; Torres, Lorenzo Herrero; Sanz, Ignacio Pereira

    2008-01-01

    Throughout the history, many devices have been used for breaking urinary tract stones. StoneBreaker (LMA Urology, Gland, Switzerland) is a second generation of intracorporeal lithotripter, pneumatic and portable, which adds several new advantages, like effectiveness in stone fragmentation and easy handling, very useful during percutaneous lithotripsy. We report the case of a 40 year-old male patient, with a left kidney pyelic lithiasis, who was treated by percutaneous lithotripsy, under general anaesthesia, with StoneBreaker (LMA Urology, Gland, Switzerland) as lithotripter. StoneBreaker (LMA Urology, Gland, Switzerland) is a lithotripter usable with rigid and semirigid ureteroscopes, much more powerful than its predecessors. It is able to decrease the number of shocks necessary for stone fragmentation, without bigger tissue reaction. It also has a more comfortable design due to the absence of connections, and its power by replaceable carbon dioxide cartridges.

  7. VIEW OF JOHN ELDER OF JEANNETTE BADGE NO. 66. BREAKER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF JOHN ELDER OF JEANNETTE BADGE NO. 66. BREAKER FOR GENERAL GLASS COMPANY. TAKEN ON BREAKER FLOOR IN FRONT OF BUCK USED TO HOLD GLASS. WORK EQUIPMENT INCLUDES: HARD HAT, SAFETY GLASSES, PROTECTIVE SLEEVES, LEATHER APRON, GLOVES WITH RUBBER PADS ("METATARSALS") WITH OVER STEEL-TOED SHOES. - Chambers-McKee Window Glass Company, Furnace No. 2, Clay Avenue Extension, Jeannette, Westmoreland County, PA

  8. Metal vapor arc switch electromagnetic accelerator technology

    NASA Technical Reports Server (NTRS)

    Mongeau, P. P.

    1984-01-01

    A multielectrode device housed in an insulator vacuum vessel, the metal vapor vacuum switch has high power capability and can hold off voltages up to the 100 kilovolt level. Such switches can be electronically triggered and can interrupt or commutate at a zero current crossing. The physics of arc initiation, arc conduction, and interruption are examined, including material considerations; inefficiencies; arc modes; magnetic field effects; passive and forced extinction; and voltage recovery. Heating, electrode lifetime, device configuration, and external circuit configuration are discussed. The metal vapor vacuum switch is compared with SCRs, GTOs, spark gaps, ignitrons, and mechanical breakers.

  9. Surface Flashover on Epoxy-Resin Printed Circuit Boards in Vacuum under Electron Irradiation

    NASA Astrophysics Data System (ADS)

    Fujii, Haruhisa; Hasegawa, Taketoshi; Osuga, Hiroyuki; Matsui, Katsuaki

    This paper deals with the surface flashover characteristics of dielectric material in vacuum during electron beam irradiation in order to design adequately the conductive patterns on printed circuit boards used inside a spacecraft. The dielectric material, glass-fiber reinforced epoxy resin, and the electrodes printed on it were irradiated with electrons of the energy of 3-10 keV. DC high voltage was applied between the two electrodes during electron irradiation. The voltage was increased stepwise until the surface flashover occurred on the dielectric material. We obtained the results that the surface flashover voltage increased with the insulation distance between the electrodes but electron irradiation made the flashover voltage lower. The flashover voltage characteristics were obtained as parameters of the electrode distance and the energy of the electron beam.

  10. 40 CFR 63.1063 - Floating roof requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... opening except those for automatic bleeder vents (vacuum breaker vents) and rim space vents shall have its... vents (vacuum breaker vents), rim space vents, leg sleeves, and deck drains shall be equipped with a... automatic bleeder vent (vacuum breaker vent) and rim space vent shall be equipped with a gasketed lid...

  11. 40 CFR 63.1063 - Floating roof requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... opening except those for automatic bleeder vents (vacuum breaker vents) and rim space vents shall have its... vents (vacuum breaker vents), rim space vents, leg sleeves, and deck drains shall be equipped with a... automatic bleeder vent (vacuum breaker vent) and rim space vent shall be equipped with a gasketed lid...

  12. 40 CFR 63.1063 - Floating roof requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... opening except those for automatic bleeder vents (vacuum breaker vents) and rim space vents shall have its... vents (vacuum breaker vents), rim space vents, leg sleeves, and deck drains shall be equipped with a... automatic bleeder vent (vacuum breaker vent) and rim space vent shall be equipped with a gasketed lid...

  13. 40 CFR 63.1063 - Floating roof requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... opening except those for automatic bleeder vents (vacuum breaker vents) and rim space vents shall have its... vents (vacuum breaker vents), rim space vents, leg sleeves, and deck drains shall be equipped with a... automatic bleeder vent (vacuum breaker vent) and rim space vent shall be equipped with a gasketed lid...

  14. Expanding sheath in a bounded plasma in the context of the post-arc phase of a vacuum arc

    NASA Astrophysics Data System (ADS)

    Sarrailh, P.; Garrigues, L.; Hagelaar, G. J. M.; Sandolache, G.; Rowe, S.; Jusselin, B.; Boeuf, J. P.

    2008-01-01

    A numerical model of sheath expansion and plasma decay in a bounded plasma subjected to a linearly increasing voltage has been developed. Numerical results obtained with a hybrid-MB model (Maxwell-Boltzmann electrons, particle ions and Poisson's equations) are compared with analytical theory and results from particle-in-cell (PIC) simulations. The hybrid-MB model is similar to models used for plasma immersion ion implantation except that plasma decay due to particle losses to the electrodes is taken into account. The comparisons with more accurate and much more time consuming PIC models show that the hybrid-MB model provides a very satisfactory description of the sheath expansion and plasma decay even for conditions where the grid spacing is much larger than the Debye length. The model is used for high plasma density conditions, corresponding to the post-arc phase of a vacuum arc circuit breaker where a vacuum gap is subject to a transient recovery voltage (TRV) after it has ceased to sustain a vacuum arc. The results show that the plasma sheath expansion is subsonic under these conditions, and that the plasma starts to decay exponentially after two rarefaction waves from the cathode and anode merge in the centre of the gap. A parametric study also shows the strong influence of the TRV rise rate and initial plasma density on the plasma decay time and on the ion current collected by each electrode. The effect of collisions between charged particles and metal atoms resulting for the electrode evaporation is also discussed.

  15. Adaptive sequential controller

    DOEpatents

    El-Sharkawi, Mohamed A.; Xing, Jian; Butler, Nicholas G.; Rodriguez, Alonso

    1994-01-01

    An adaptive sequential controller (50/50') for controlling a circuit breaker (52) or other switching device to substantially eliminate transients on a distribution line caused by closing and opening the circuit breaker. The device adaptively compensates for changes in the response time of the circuit breaker due to aging and environmental effects. A potential transformer (70) provides a reference signal corresponding to the zero crossing of the voltage waveform, and a phase shift comparator circuit (96) compares the reference signal to the time at which any transient was produced when the circuit breaker closed, producing a signal indicative of the adaptive adjustment that should be made. Similarly, in controlling the opening of the circuit breaker, a current transformer (88) provides a reference signal that is compared against the time at which any transient is detected when the circuit breaker last opened. An adaptive adjustment circuit (102) produces a compensation time that is appropriately modified to account for changes in the circuit breaker response, including the effect of ambient conditions and aging. When next opened or closed, the circuit breaker is activated at an appropriately compensated time, so that it closes when the voltage crosses zero and opens when the current crosses zero, minimizing any transients on the distribution line. Phase angle can be used to control the opening of the circuit breaker relative to the reference signal provided by the potential transformer.

  16. Solid-state circuit breaker with current-limiting characteristic using a superconducting coil

    DOEpatents

    Boenig, H.J.

    1982-08-16

    A thyristor bridge interposes an ac source and a load. A series connected DC source and superconducting coil within the bridge biases the thyristors thereof so as to permit bidirectional ac current flow therethrough under normal operating conditions. Upon a fault condition a control circuit triggers the thyristors so as to reduce ac current flow therethrough to zero in less than two eyeles and to open the bridge thereafter. Upon a temporary overload condition the control circuit triggers the thyristors so as to limit ac current flow therethrough to an acceptable level.

  17. Solid-state circuit breaker with current limiting characteristic using a superconducting coil

    DOEpatents

    Boenig, Heinrich J.

    1984-01-01

    A thyristor bridge interposes an ac source and a load. A series connected DC source and superconducting coil within the bridge biases the thyristors thereof so as to permit bidirectional ac current flow therethrough under normal operating conditions. Upon a fault condition a control circuit triggers the thyristors so as to reduce ac current flow therethrough to zero in less than two cycles and to open the bridge thereafter. Upon a temporary overload condition the control circuit triggers the thyristors so as to limit ac current flow therethrough to an acceptable level.

  18. Experimental investigation on the initial expansion stage of vacuum arc on cup-shaped TMF contacts

    NASA Astrophysics Data System (ADS)

    Wang, Ting; Xiu, Shixin; Liu, Zixi; Zhang, Yanzhe; Feng, Dingyu

    2018-02-01

    Arc behavior and measures to control it directly affect the properties of vacuum circuit breakers. Nowadays, transverse magnetic field (TMF) contacts are widely used for medium voltages. A magnetic field perpendicular to the current direction between the TMF contacts makes the arc move, transmitting its energy to the whole contact and avoiding excessive local ablation. Previous research on TMF arc behavior concentrated mainly on the arc movement and less on the initial stage (from arc ignition to an unstable arc column). A significant amount of experiment results suggest that there is a short period of arc stagnation after ignition. The duration of this arc stagnation and the arc characteristics during this stage affect the subsequent arc motion and even the breaking property of interrupters. The present study is of the arc characteristics in the initial stage. Experiments were carried out in a demountable vacuum chamber with cup-shaped TMF contacts. Using a high-speed camera, both single-point arc ignition mode and multiple-point arc ignition (MPAI) mode were observed. The experimental data show that the probability of MPAI mode occurring is related to the arc current. The influences of arc-ignition mode, arc current, and contact diameter on the initial expansion process were investigated. In addition, simulations were performed to analyze the multiple arc expansion process mechanically. Based on the experimental phenomena and simulation results, the mechanism of the arc expansion motion was analyzed.

  19. "Hyperglutamatergic cortico-striato-thalamo-cortical circuit" breaker drugs alleviate tics in a transgenic circuit model of Tourette׳s syndrome.

    PubMed

    Nordstrom, Eric J; Bittner, Katie C; McGrath, Michael J; Parks, Clinton R; Burton, Frank H

    2015-12-10

    The brain circuits underlying tics in Tourette׳s syndrome (TS) are unknown but thought to involve cortico/amygdalo-striato-thalamo-cortical (CSTC) loop hyperactivity. We previously engineered a transgenic mouse "circuit model" of TS by expressing an artificial neuropotentiating transgene (encoding the cAMP-elevating, intracellular A1 subunit of cholera toxin) within a small population of dopamine D1 receptor-expressing somatosensory cortical and limbic neurons that hyperactivate cortico/amygdalostriatal glutamatergic output circuits thought to be hyperactive in TS and comorbid obsessive-compulsive (OC) disorders. As in TS, these D1CT-7 ("Ticcy") transgenic mice׳s tics were alleviated by the TS drugs clonidine and dopamine D2 receptor antagonists; and their chronic glutamate-excited striatal motor output was unbalanced toward hyperactivity of the motoric direct pathway and inactivity of the cataleptic indirect pathway. Here we have examined whether these mice׳s tics are countered by drugs that "break" sequential elements of their hyperactive cortical/amygdalar glutamatergic and efferent striatal circuit: anti-serotonoceptive and anti-noradrenoceptive corticostriatal glutamate output blockers (the serotonin 5-HT2a,c receptor antagonist ritanserin and the NE alpha-1 receptor antagonist prazosin); agmatinergic striatothalamic GABA output blockers (the presynaptic agmatine/imidazoline I1 receptor agonist moxonidine); and nigrostriatal dopamine output blockers (the presynaptic D2 receptor agonist bromocriptine). Each drug class alleviates tics in the Ticcy mice, suggesting a hyperglutamatergic CSTC "tic circuit" could exist in TS wherein cortical/amygdalar pyramidal projection neurons׳ glutamatergic overexcitation of both striatal output neurons and nigrostriatal dopaminergic modulatory neurons unbalances their circuit integration to excite striatothalamic output and create tics, and illuminating new TS drug strategies. Copyright © 2015 The Authors. Published by

  20. 76 FR 9374 - Proposed Extension of Existing Information Collection; Examinations and Testing of Electrical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-17

    ... related detached components; 75.800-4 Testing, examination and maintenance of circuit breakers; record; 75...-4 Testing, examination and maintenance of circuit breakers; record; 75.1001-1 Devices for..., testing, and maintenance; 77.800-2 Testing, examination and maintenance of circuit breakers; record; and...

  1. Apparatus for and method of testing an electrical ground fault circuit interrupt device

    DOEpatents

    Andrews, L.B.

    1998-08-18

    An apparatus for testing a ground fault circuit interrupt device includes a processor, an input device connected to the processor for receiving input from an operator, a storage media connected to the processor for storing test data, an output device connected to the processor for outputting information corresponding to the test data to the operator, and a calibrated variable load circuit connected between the processor and the ground fault circuit interrupt device. The ground fault circuit interrupt device is configured to trip a corresponding circuit breaker. The processor is configured to receive signals from the calibrated variable load circuit and to process the signals to determine a trip threshold current and/or a trip time. A method of testing the ground fault circuit interrupt device includes a first step of providing an identification for the ground fault circuit interrupt device. Test data is then recorded in accordance with the identification. By comparing test data from an initial test with test data from a subsequent test, a trend of performance for the ground fault circuit interrupt device is determined. 17 figs.

  2. Apparatus for and method of testing an electrical ground fault circuit interrupt device

    DOEpatents

    Andrews, Lowell B.

    1998-01-01

    An apparatus for testing a ground fault circuit interrupt device includes a processor, an input device connected to the processor for receiving input from an operator, a storage media connected to the processor for storing test data, an output device connected to the processor for outputting information corresponding to the test data to the operator, and a calibrated variable load circuit connected between the processor and the ground fault circuit interrupt device. The ground fault circuit interrupt device is configured to trip a corresponding circuit breaker. The processor is configured to receive signals from the calibrated variable load circuit and to process the signals to determine a trip threshold current and/or a trip time. A method of testing the ground fault circuit interrupt device includes a first step of providing an identification for the ground fault circuit interrupt device. Test data is then recorded in accordance with the identification. By comparing test data from an initial test with test data from a subsequent test, a trend of performance for the ground fault circuit interrupt device is determined.

  3. 78 FR 8659 - Self-Regulatory Organizations; BATS Y-Exchange, Inc.; Notice of Filing and Immediate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... proposed changes to the market- wide circuit breaker on a pilot basis for a period scheduled to start on... circuit breaker pilot to April 8, 2013 in order for the implementation date for the market-wide circuit..., SR-NASD-98-27, and SR-Phlx-98-15). Once a Rule 11.18 circuit breaker is in effect, trading in all...

  4. 78 FR 8680 - Self-Regulatory Organizations; BATS Exchange, Inc.; Notice of Filing and Immediate Effectiveness...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... changes to the market- wide circuit breaker on a pilot basis for a period scheduled to start on February 4... circuit breaker pilot to April 8, 2013 in order for the implementation date for the market-wide circuit..., SR-NASD-98-27, and SR-Phlx-98-15). Once a Rule 11.18 circuit breaker is in effect, trading in all...

  5. Computational and Experimental Studies on β-Sheet Breakers Targeting Aβ1–40 Fibrils

    PubMed Central

    Minicozzi, Velia; Chiaraluce, Roberta; Consalvi, Valerio; Giordano, Cesare; Narcisi, Claudia; Punzi, Pasqualina; Rossi, Giancarlo C.; Morante, Silvia

    2014-01-01

    In this work we present and compare the results of extensive molecular dynamics simulations of model systems comprising an Aβ1–40 peptide in water in interaction with short peptides (β-sheet breakers) mimicking the 17–21 region of the Aβ1–40 sequence. Various systems differing in the customized β-sheet breaker structure have been studied. Specifically we have considered three kinds of β-sheet breakers, namely Ac-LPFFD-NH2 and two variants thereof, one obtained by substituting the acetyl group with the sulfonic amino acid taurine (Tau-LPFFD-NH2) and a second novel one in which the aspartic acid is substituted by an asparagine (Ac-LPFFN-NH2). Thioflavin T fluorescence, circular dichroism, and mass spectrometry experiments have been performed indicating that β-sheet breakers are able to inhibit in vitro fibril formation and prevent the β sheet folding of portions of the Aβ1–40 peptide. We show that molecular dynamics simulations and far UV circular dichroism provide consistent evidence that the new Ac-LPFFN-NH2 β-sheet breaker is more effective than the other two in stabilizing the native α-helix structure of Aβ1–40. In agreement with these results thioflavin T fluorescence experiments confirm the higher efficiency in inhibiting Aβ1–40 aggregation. Furthermore, mass spectrometry data and molecular dynamics simulations consistently identified the 17–21 Aβ1–40 portion as the location of the interaction region between peptide and the Ac-LPFFN-NH2 β-sheet breaker. PMID:24584938

  6. "I just wanted to get away": An analysis of spring breakers' travel motivations

    Treesearch

    Nuno F. Ribeiro; Paul E. Durrenberger; Careen M. Yarnal; Garry E. Chick

    2010-01-01

    Scholarly research on Spring Break has grown substantially and has often associated spring breakers' motivations with a number of risky behaviors. Recent research, however, has challenged these assumptions. The purpose of this study was to examine spring breakers' motivations for going on Spring Break. Unlike the media portrayal of Spring Break as a time of...

  7. 78 FR 8666 - Self-Regulatory Organizations; The NASDAQ Stock Market LLC; Notice of Filing and Immediate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... adopted the proposed changes to the market-wide circuit breakers on a pilot basis for a period that... to April 8, 2013. The proposal would delay the operative date of the market-wide circuit breaker pilot to April 8, 2013 in order for the implementation date for the market-wide circuit breaker pilot...

  8. Lessons Learned "Establishing an Electrically Safe Work Condition" Specifically related to Racking Electrical Breakers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Martinez, Tommy Robert; Romero, Philbert Roland; Garcia, Samuel Anthony

    During low voltage electrical equipment maintenance, a bad breaker was identified. The breaker was racked out from the substation cubicle without following the hazardous energy control process identified in the Integrated Work Document (IWD). The IWD required the substation to be in an electrically safe work condition prior to racking the breaker. Per NFPA 70E requirements, electrical equipment shall be put into an electrically safe work condition before an employee performs work on or interacts with equipment in a manner that increases the likelihood of creating an arc flash. Racking in or out a breaker on an energized bus maymore » increase the likelihood of creating an arc flash dependent on equipment conditions. A thorough risk assessment must be performed prior to performing such a task. The risk assessment determines the risk control measures to be put in place prior to performing the work. Electrical Safety Officers (ESO) can assist in performing risk assessments and incorporating risk control measures.« less

  9. THERMOCOUPLE VACUUM GAUGE

    DOEpatents

    Price, G.W.

    1954-08-01

    A protector device is described for use in controlling the pressure within a cyclotron. In particular, an electrical circuit functions to actuate a vacuum pump when a predetermined low pressure is reached and disconnect the pump when the pressure increases abcve a certain value. The principal feature of the control circuit lies in the use of a voltage divider network at the input to a relay control tube comprising two parallel, adjustable resistances wherein one resistor is switched into the circuit when the relay connects the pump to a power source. With this arrangement the relay is energized at one input level received from a sensing element within the cyclotron chamber and is de-energized when a second input level, representing the higher pressure limit, is reached.

  10. Application of vacuum metallurgy to separate pure metal from mixed metallic particles of crushed waste printed circuit board scraps.

    PubMed

    Zhan, Lu; Xu, Zhenming

    2008-10-15

    The principle of separating pure metal from mixed metallic particles (MMPs) byvacuum metallurgy is that the vapor pressures of various metals at the same temperature are different As a result, the metal with high vapor pressure and low boiling point can be separated from the mixed metals through distillation or sublimation, and then it can be recycled through condensation under a certain condition. The vacuum metallurgy separation (VMS) of MMPs of crushed waste printed circuit boards (WPCBs) has been studied in this paper. Theoretical analyses show that the MMPs (copper, zinc, bismuth, lead, and indium, for example) can be separated by vacuum metallurgy. The copper particles (0.15-0.20 mm) and zinc particles (<0.30 mm) were chosen to simulate the MMPs of crushed WPCBs. Experimental results show that the separated efficiency of zinc in the copper-rich particles achieves 96.19 wt % when the vacuum pressure is 0.01-0.10 Pa, the heating temperature is 1123 K, and the heating time is 105 min. Under this operation condition, the separated efficiency of zinc in the copper-rich particles from crushed WPCBs achieves 97.00 wt % and the copper purity increases from 90.68 to 99.84 wt %.

  11. 78 FR 8638 - Self-Regulatory Organizations; National Stock Exchange, Inc.; Notice of Filing and Immediate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... Change To Delay the Operative Date of Rule 11.20A Regarding Market-Wide Circuit Breakers Due to... the market- wide circuit breakers on a pilot basis for a period scheduled to start on February 4, 2013... changed to April 8, 2013. The proposal would delay the operative date of the market-wide circuit breaker...

  12. Response of crownvetch planted on anthracite breaker refuse

    Treesearch

    Miroslaw M. Czapowskyj; John P. Mikulecky; Edward A. Sowa

    1968-01-01

    Lime applications were essential to establishment of crownvetch (Coronilla vuria L.) on coal breaker refuse in the Pennsylvania Anthracite Region, and mulch treatments were highly beneficial. Fertilizer applications had only slight effect on either establishment or growth.

  13. 78 FR 8675 - Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... Proposed Rule Change to Amend ISE Rule 2102 to Extend the Market-Wide Circuit Breaker Pilot Program January...- wide circuit breaker on a pilot basis for a period that corresponds to the pilot period for the LULD... delay the operative date of the market-wide circuit breaker pilot to April 8, 2013 in order for the...

  14. DIFFERENTIAL FAULT SENSING CIRCUIT

    DOEpatents

    Roberts, J.H.

    1961-09-01

    A differential fault sensing circuit is designed for detecting arcing in high-voltage vacuum tubes arranged in parallel. A circuit is provided which senses differences in voltages appearing between corresponding elements likely to fault. Sensitivity of the circuit is adjusted to some level above which arcing will cause detectable differences in voltage. For particular corresponding elements, a group of pulse transformers are connected in parallel with diodes connected across the secondaries thereof so that only voltage excursions are transmitted to a thyratron which is biased to the sensitivity level mentioned.

  15. Dynamic process of high-current vacuum arc with consideration of magnetic field delay: numerical simulation and comparisons with the experiments

    NASA Astrophysics Data System (ADS)

    Yang, Dingge; Wang, Lijun; Jia, Shenli; Huo, Xintao; Zhang, Ling; Liu, Ke; Shi, Zongqian

    2009-03-01

    Based on a two-dimensional magnetohydrodynamic model, the dynamic process in a high-current vacuum arc (as in a high-power circuit breaker) was simulated and analysed. A half-wave of sinusoidal current was represented as a series of discrete steps, rather than as a continuous wave. The simulation was done at each step, i.e. at each of the discrete current values. In the simulation, the phase delay by which the axial magnetic field lags the current was taken into account. The curves which represent the variation of arc parameters (such as electron temperature) look sinusoidal, but the parameter values at a discrete moment in the second 1/4 cycle are smaller than those at the corresponding moment in the first 1/4 cycle (although the currents are equal at these two moments). This is perhaps mainly due to the magnetic field delay. In order to verify the correctness of the simulation, the simulation results were compared in part with the experimental results. It was seen from the experimental results that the arc column was darker but more uniform in the second 1/4 cycle than in the first 1/4 cycle, in agreement with the simulation results.

  16. GRID BLACKOUT IN VACUUM TUBES

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hardin, K.D.

    1961-06-01

    A method which gives quantitative data is presented which allows for characterization of the grid blackout effect and is applicable to calculation of circuit degradation. Data are presented for several tube types which show developed bias and discharge time constants as a function of pulse input conditions. Blackout can seriously change the performance of any vacuum tube circuit which utilizes the tube in positive grid operation. The effects on CW oscillators and UHF mixers are discussed. An equivalent circuit which simulates some portions of the blackout phenomenon is presented and used to calculate effective capacitance and resistance associated with themore » grid surface. (auth)« less

  17. Contact dynamics recording and analysis system using an optical fiber sensor approach

    NASA Astrophysics Data System (ADS)

    Anghel, F.; Pavelescu, D.; Grattan, K. T. V.; Palmer, A. W.

    1997-09-01

    A contact dynamics recording and analysis system configured using an optical fiber sensor has been developed having been designed with a particular application to the accurate and time-varying description of moving contact operating during electrical arc breaking, in an experimental platform simulating the operation of a vacuum circuit breaker. The system utilizes dynamic displacement measurement and data recording and a post-process data analysis to reveal the dynamic speed and acceleration data of the equipment.

  18. 46 CFR 64.19 - External pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... HANDLING SYSTEMS Standards for an MPT § 64.19 External pressure. (a) A tank without a vacuum breaker must be designed to withstand an external pressure of 71/2 psig or more. (b) A tank with a vacuum breaker...

  19. 46 CFR 64.19 - External pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... HANDLING SYSTEMS Standards for an MPT § 64.19 External pressure. (a) A tank without a vacuum breaker must be designed to withstand an external pressure of 71/2 psig or more. (b) A tank with a vacuum breaker...

  20. 46 CFR 64.19 - External pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... HANDLING SYSTEMS Standards for an MPT § 64.19 External pressure. (a) A tank without a vacuum breaker must be designed to withstand an external pressure of 71/2 psig or more. (b) A tank with a vacuum breaker...

  1. 46 CFR 64.19 - External pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... HANDLING SYSTEMS Standards for an MPT § 64.19 External pressure. (a) A tank without a vacuum breaker must be designed to withstand an external pressure of 71/2 psig or more. (b) A tank with a vacuum breaker...

  2. 46 CFR 64.19 - External pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... HANDLING SYSTEMS Standards for an MPT § 64.19 External pressure. (a) A tank without a vacuum breaker must be designed to withstand an external pressure of 71/2 psig or more. (b) A tank with a vacuum breaker...

  3. Humidity Control in the U.S. Air Force Aircraft Service Shelter

    DTIC Science & Technology

    1988-06-30

    printed circuit board control module , terminal boards, and blowt.r, etc.) are off-the-shelf commercial components. Only the humidifier ho:;Ift, I...indication of the shelter RH. - Circuit Breaker: A 20 amp, three pole breaker is providud fur equipment protection. o Water Storage Tank. A stainless...tapped into the shelter’s existing electrical system at the panelboard, on the load side of the 100 Amp main AC circuit breaker. Power is then

  4. Thermophysical and radiation properties of high-temperature C4F8-CO2 mixtures to replace SF6 in high-voltage circuit breakers

    NASA Astrophysics Data System (ADS)

    Zhong, Linlin; Cressault, Yann; Teulet, Philippe

    2018-03-01

    C4F8-CO2 mixtures are one of the potential substitutes to SF6 in high-voltage circuit breakers. However, the arc quenching ability of C4F8-CO2 mixtures is still unknown. In order to provide the necessary basic data for the further investigation of arc quenching performance, the compositions, thermodynamic properties, transport coefficients, and net emission coefficients (NEC) of various C4F8-CO2 mixtures are calculated at temperatures of 300-30 000 K in this work. The thermodynamic properties are presented as the product of mass density and specific heat, i.e., ρCp. The transport coefficients include electrical conductivity, viscosity, and thermal conductivity. The atomic and molecular radiation are both taken into account in the calculation of NEC. The comparison of the properties between SF6 and C4F8-CO2 mixtures is also discussed to find their differences. The results of compositions show that C4F8-CO2 mixtures have a distinctive advantage over other alternative gases e.g., CF3I and C3F8, because the dissociative product (i.e., C4F6) of C4F8 at low temperatures has a very high dielectric strength. This is good for an arc quenching medium to endure the arc recovery phase. Compared with SF6, C4F8-CO2 mixtures present lower ρCp at temperatures below 2800 K and larger thermal conductivity above 2800 K. Based on the position of peaks in thermal conductivity, we predict that the cooling of C4F8-CO2 arc will be slowed down at higher temperatures than that of SF6 arc. It is also found that the mixing of CO2 shows slight effects on the electrical conductivity and NEC of C4F8-CO2 mixtures.

  5. Experimental study of Siphon breaker about size effect in real scale reactor design

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kang, S. H.; Ahn, H. S.; Kim, J. M.

    2012-07-01

    Rupture accident within the pipe of a nuclear reactor is one of the main causes of a loss of coolant accident (LOCA). Siphon-breaking is a passive method that can prevent a LOCA. In this study, either a line or a hole is used as a siphon-breaker, and the effect of various parameters, such as the siphon-breaker size, pipe rupture point, pipe rupture size, and the presence of an orifice, are investigated using an experimental facility similar in size to a full-scale reactor. (authors)

  6. Effect of magnetic attachment with stress breaker on lateral stress to abutment tooth under overdenture.

    PubMed

    Gonda, T; Ikebe, K; Ono, T; Nokubi, T

    2004-10-01

    Recently, a newly developed magnetic attachment with stress breaker was used in retentive components in overdentures. Excessive lateral stress has a more harmful effect on natural teeth than axial stress, and the magnetic attachment with stress breaker is expected to reduce lateral forces on abutment teeth and protect it teeth from excessive stress. However, the properties of this retainer have not yet been determined experimentally. This study compares the lateral forces on abutment teeth for three retainers under loading on the denture base in a model study. A mandibular simulation model is constructed to measure lateral stress. Three types of retentive devices are attached to the canine root. These devices include the conventional root coping, the conventional magnetic attachment and the new magnetic attachment with stress breaker. For each retentive device, load is generated on the occlusal table of the model overdenture, and the lateral stress on the canine root and the displacement of the overdenture measured. The magnetic attachment with stress breaker does not displace the denture and exhibits lower lateral stress in the canine root than conventional root coping and magnetic attachments.

  7. 54. CLEARANCE OF SITE PRIOR TO CONSTRUCTION OF BREAKER BUILDING, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. CLEARANCE OF SITE PRIOR TO CONSTRUCTION OF BREAKER BUILDING, AND CONSTRUCTION OF EMBANKMENT FOR RAILROAD SPUR. c.1898 (AKZO No. A-3) - Avery Island Salt Works, Akzo Salt Incorporated, Avery Island, Iberia Parish, LA

  8. Electric Propulsion Laboratory Vacuum Chamber

    NASA Image and Video Library

    1964-06-21

    Engineer Paul Reader and his colleagues take environmental measurements during testing of a 20-inch diameter ion engine in a vacuum tank at the Electric Propulsion Laboratory (EPL). Researchers at the Lewis Research Center were investigating the use of a permanent-magnet circuit to create the magnetic field required power electron bombardment ion engines. Typical ion engines use a solenoid coil to create this magnetic field. It was thought that the substitution of a permanent magnet would create a comparable magnetic field with a lower weight. Testing of the magnet system in the EPL vacuum tanks revealed no significant operational problems. Reader found the weight of the two systems was similar, but that the thruster’s efficiency increased with the magnet. The EPL contained a series of large vacuum tanks that could be used to simulate conditions in space. Large vacuum pumps reduced the internal air pressure, and a refrigeration system created the cryogenic temperatures found in space.

  9. 40 CFR 65.44 - External floating roof (EFR).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... external floating roof except for automatic bleeder vents (vacuum breaker vents) and rim space vents does... floating roof shall meet the following specifications: (i) Except for automatic bleeder vents (vacuum breaker vents) and rim space vents, each opening in the noncontact external floating roof shall provide a...

  10. 40 CFR 65.44 - External floating roof (EFR).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... external floating roof except for automatic bleeder vents (vacuum breaker vents) and rim space vents does... floating roof shall meet the following specifications: (i) Except for automatic bleeder vents (vacuum breaker vents) and rim space vents, each opening in the noncontact external floating roof shall provide a...

  11. 40 CFR 65.44 - External floating roof (EFR).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... external floating roof except for automatic bleeder vents (vacuum breaker vents) and rim space vents does... floating roof shall meet the following specifications: (i) Except for automatic bleeder vents (vacuum breaker vents) and rim space vents, each opening in the noncontact external floating roof shall provide a...

  12. Study of feasibility of solid-state electric switch gear for aircraft and spacecraft

    NASA Technical Reports Server (NTRS)

    Buchanan, E.; Waddington, D.

    1973-01-01

    The design of a solid-state circuit breaker that can be interconnected to a second breaker to form a transfer switch is presented. The breaker operates on a nominal 270-V dc circuit and controls power to loads of up to 15 A. Automatic overload trip is provided as a function of excess energy measured through the breaker and/or excess current through the breaker. After an overload trip, up to nine preprogrammable attempts to reclose may be tried with programmable delays between each attempt. The breaker or switch is remotely controllable. Test data on performance in the laboratory over temperatures from -45 to 100 C are provided. The feasibility of solid-state switch gear has been established.

  13. Switching of High-Voltage Cable Lines with Shunt Reactors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sheskin, E. B., E-mail: evgeniy.sheskin@gmail.com; Evdokunin, G. A.

    2016-05-15

    The problem of disconnecting high-voltage cable lines with shunt reactors by SF{sub 6} circuit breakers is discussed. In these schemes it is possible to have a significant aperiodic component of the circuit breaker current that can prevent opening of the breaker. The authors propose methods for application to cable transmission lines which they believe will be optimal for ensuring normal disconnects.

  14. 76 FR 24358 - Airworthiness Directives; Dassault-Aviation Model FALCON 7X Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ...-wheels (WOW) proximity sensor wiring, both circuit breakers that supply power to that wiring will trip... sensor wiring, both circuit breakers that supply power to that wiring will trip, causing simultaneous de... robustness against short circuit of the proximity sensors wiring by adding dedicated fuses to each [[Page...

  15. Lime retention in anthracite coal-breaker refuse

    Treesearch

    Miroslaw M. Czapowskyj; Edward A. Sowa

    1973-01-01

    Hydrated lime was applied to extremely acid anthracite coal-breaker refuse at rates of 2.5 and 5.0 tons per acre. The lime raised the pH to neutral range, and this range was still in evidence 7 years after treatment. The pH readings decreased with the depth of the refuse profile, and below 9 inches they approximated those of the control plots. The 2.5-tons-of-lime-per-...

  16. Lime helps establish crownvetch on coal-breaker refuse

    Treesearch

    Miroslaw M. Czapowskyj; Edward A. Sowa

    1976-01-01

    A study was begun in 1965 to determine the effect of lime fertilizer, and mulch on the establishment and growth of crownvetch crowns planted on anthracite coal-breaker refuse. After 7 years the lime application had by far the strongest effect. Both 2.5 and 5.0 tons per acre increased survival and ground cover manyfold, and both treatments were equally beneficial from...

  17. Detusking fence-breaker elephants as an approach in human-elephant conflict mitigation.

    PubMed

    Mutinda, Matthew; Chenge, Geoffrey; Gakuya, Francis; Otiende, Moses; Omondi, Patrick; Kasiki, Samuel; Soriguer, Ramón C; Alasaad, Samer

    2014-01-01

    Human-elephant conflict (HEC) is a recurring problem that appears wherever the range of elephants and humans overlap. Different methods including the use of electric fences are used worldwide to mitigate this conflict. Nonetheless, elephants learn quickly that their tusks do not conduct electricity and use them to break down fences (fence-breakers). In Lewa Wildlife Conservancy, Kenya, destructive elephants (Loxodonta africana) were monitored between 2010 and 2013. The fence-breaking rate reached four incidents (fence-breaking) per elephant per 100 days. Ten bull males and 57 females were identified as fence-breakers. The bulls were involved in 85.07% and the females in 14.93% of incidents. The Kenya Wildlife Service approved detusking (partial cutting of tusks) in four of the 10 fence-breakers as a way of preventing them from breaking down fences, thereby mitigating HEC in the Conservancy. The result of the detusking was a drastic six-fold reduction in damage to fences (range: 1.67 to 14.5 times less fence-breaking) by the four worst fence-breaker elephants, because with trimmed tusks elephants lack the tools to break down fences. Detusking could not totally eliminate fence destruction because, despite lacking their tools, elephants can still destroy fences using their heads, bodies and trunks, albeit less effectively. On the other hand, apart from inherent aesthetic considerations, the detusking of elephants may have certain negative effects on factors such as elephants' social hierarchies, breeding, mate selection and their access to essential minerals and food. Elephant detusking seems to be effective in drastically reducing fence-breaking incidents, nonetheless its negative effects on behaviour, access to food and its aesthetical consequences still need to be further studied and investigated.

  18. Detusking Fence-Breaker Elephants as an Approach in Human-Elephant Conflict Mitigation

    PubMed Central

    Mutinda, Matthew; Chenge, Geoffrey; Gakuya, Francis; Otiende, Moses; Omondi, Patrick; Kasiki, Samuel; Soriguer, Ramón C.; Alasaad, Samer

    2014-01-01

    Background Human-elephant conflict (HEC) is a recurring problem that appears wherever the range of elephants and humans overlap. Different methods including the use of electric fences are used worldwide to mitigate this conflict. Nonetheless, elephants learn quickly that their tusks do not conduct electricity and use them to break down fences (fence-breakers). Methodology/Principal Findings In Lewa Wildlife Conservancy, Kenya, destructive elephants (Loxodonta africana) were monitored between 2010 and 2013. The fence-breaking rate reached four incidents (fence-breaking) per elephant per 100 days. Ten bull males and 57 females were identified as fence-breakers. The bulls were involved in 85.07% and the females in 14.93% of incidents. The Kenya Wildlife Service approved detusking (partial cutting of tusks) in four of the 10 fence-breakers as a way of preventing them from breaking down fences, thereby mitigating HEC in the Conservancy. The result of the detusking was a drastic six-fold reduction in damage to fences (range: 1.67 to 14.5 times less fence-breaking) by the four worst fence-breaker elephants, because with trimmed tusks elephants lack the tools to break down fences. Detusking could not totally eliminate fence destruction because, despite lacking their tools, elephants can still destroy fences using their heads, bodies and trunks, albeit less effectively. On the other hand, apart from inherent aesthetic considerations, the detusking of elephants may have certain negative effects on factors such as elephants' social hierarchies, breeding, mate selection and their access to essential minerals and food. Conclusions Elephant detusking seems to be effective in drastically reducing fence-breaking incidents, nonetheless its negative effects on behaviour, access to food and its aesthetical consequences still need to be further studied and investigated. PMID:24614538

  19. 75 FR 82327 - Airworthiness Directives; Dassault-Aviation Model FALCON 7X Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-30

    ... wiring, both circuit breakers that supply power to that wiring will trip, causing simultaneous de-power... case a short circuit occurs on a weight-on-wheels (WOW) proximity sensor wiring, both circuit breakers that supply power to that wiring will trip, causing simultaneous de-power of all WOW proximity sensors...

  20. Recycling of organic materials and solder from waste printed circuit boards by vacuum pyrolysis-centrifugation coupling technology.

    PubMed

    Zhou, Yihui; Wu, WenBiao; Qiu, Keqiang

    2011-12-01

    Here, we focused on the recycling of waste printed circuit boards (WPCBs) using vacuum pyrolysis-centrifugation coupling technology (VPCT) aiming to obtain valuable feedstock and resolve environmental pollution. The two types of WPCBs were pyrolysed at 600°C for 30 min under vacuum condition. During the pyrolysis process, the solder of WPCBs was separated and recovered when the temperature range was 400-600°C, and the rotating drum was rotated at 1000 rpm for 10 min. The type-A of WPCBs pyrolysed to form an average of 67.91 wt.% residue, 27.84 wt.% oil, and 4.25 wt.% gas; and pyrolysis of the type-B of WPCBs led to an average mass balance of 72.22 wt.% residue, 21.57 wt.% oil, and 6.21 wt.% gas. The GC-MS and FT-IR analyses showed that the two pyrolysis oils consisted mainly of phenols and substituted phenols. The pyrolysis oil can be used for fuel or chemical feedstock for further processing. The recovered solder can be recycled directly and it can also be a good resource of lead and tin for refining. The pyrolysis residues contained various metals, glass fibers and other inorganic materials, which could be recovered after further treatment. The pyrolysis gases consisted mainly of CO, CO(2), CH(4), and H(2), which could be collected and recycled. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. 76 FR 61429 - Self-Regulatory Organizations; Financial Industry Regulatory Authority, Inc.; Notice of Filing of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-04

    ... Volatility) (i) To reflect changes to market-wide circuit breaker triggers for NMS stocks, and (ii) amend... trading in all OTC Equity Securities when a market-wide circuit breaker is in effect for NMS stocks. The... Equity Securities pursuant to its authority under Rule 6440(a)(3) \\3\\ until the market-wide circuit...

  2. Integral Battery Power Limiting Circuit for Intrinsically Safe Applications

    NASA Technical Reports Server (NTRS)

    Burns, Bradley M.; Blalock, Norman N.

    2010-01-01

    A circuit topology has been designed to guarantee the output of intrinsically safe power for the operation of electrical devices in a hazardous environment. This design uses a MOSFET (metal oxide semiconductor field-effect transistor) as a switch to connect and disconnect power to a load. A test current is provided through a separate path to the load for monitoring by a comparator against a preset threshold level. The circuit is configured so that the test current will detect a fault in the load and open the switch before the main current can respond. The main current passes through the switch and then an inductor. When a fault occurs in the load, the current through the inductor cannot change immediately, but the voltage drops immediately to safe levels. The comparator detects this drop and opens the switch before the current in the inductor has a chance to respond. This circuit protects both the current and voltage from exceeding safe levels. Typically, this type of protection is accomplished by a fuse or a circuit breaker, but in order for a fuse or a circuit breaker to blow or trip, the current must exceed the safe levels momentarily, which may be just enough time to ignite anything in a hazardous environment. To prevent this from happening, a fuse is typically current-limited by the addition of the resistor to keep the current within safe levels while the fuse reacts. The use of a resistor is acceptable for non-battery applications where the wasted energy and voltage drop across the resistor can be tolerated. The use of the switch and inductor minimizes the wasted energy. For example, a circuit runs from a 3.6-V battery that must be current-limited to 200 mA. If the circuit normally draws 10 mA, then an 18-ohm resistor would drop 180 mV during normal operation, while a typical switch (0.02 ohm) and inductor (0.97 ohm) would only drop 9.9 mV. From a power standpoint, the current-limiting resistor protection circuit wastes about 18 times more power than the

  3. 78 FR 8648 - Self-Regulatory Organizations; EDGX Exchange, Inc.; Notice of Filing and Immediate Effectiveness...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... changes to the market- wide circuit breaker on a pilot basis for a period scheduled to start on February 4... circuit breaker pilot to April 8, 2013 in order for the implementation date for the market-wide circuit...-Amex-98-09, SR-BSE-98-06, SR-CHX-98-08, SR-NASD-98-27, and SR-Phlx-98-15). Once a Rule 11.14 circuit...

  4. Transmission-line-circuit model of an 85-TW, 25-MA pulsed-power accelerator

    NASA Astrophysics Data System (ADS)

    Hutsel, B. T.; Corcoran, P. A.; Cuneo, M. E.; Gomez, M. R.; Hess, M. H.; Hinshelwood, D. D.; Jennings, C. A.; Laity, G. R.; Lamppa, D. C.; McBride, R. D.; Moore, J. K.; Myers, A.; Rose, D. V.; Slutz, S. A.; Stygar, W. A.; Waisman, E. M.; Welch, D. R.; Whitney, B. A.

    2018-03-01

    We have developed a physics-based transmission-line-circuit model of the Z pulsed-power accelerator. The 33-m-diameter Z machine generates a peak electrical power as high as 85 TW, and delivers as much as 25 MA to a physics load. The circuit model is used to design and analyze experiments conducted on Z. The model consists of 36 networks of transmission-line-circuit elements and resistors that represent each of Zs 36 modules. The model of each module includes a Marx generator, intermediate-energy-storage capacitor, laser-triggered gas switch, pulse-forming line, self-break water switches, and tri-plate transmission lines. The circuit model also includes elements that represent Zs water convolute, vacuum insulator stack, four parallel outer magnetically insulated vacuum transmission lines (MITLs), double-post-hole vacuum convolute, inner vacuum MITL, and physics load. Within the vacuum-transmission-line system the model conducts analytic calculations of current loss. To calculate the loss, the model simulates the following processes: (i) electron emission from MITL cathode surfaces wherever an electric-field threshold has been exceeded; (ii) electron loss in the MITLs before magnetic insulation has been established; (iii) flow of electrons emitted by the outer-MITL cathodes after insulation has been established; (iv) closure of MITL anode-cathode (AK) gaps due to expansion of cathode plasma; (v) energy loss to MITL conductors operated at high lineal current densities; (vi) heating of MITL-anode surfaces due to conduction current and deposition of electron kinetic energy; (vii) negative-space-charge-enhanced ion emission from MITL anode surfaces wherever an anode-surface-temperature threshold has been exceeded; and (viii) closure of MITL AK gaps due to expansion of anode plasma. The circuit model is expected to be most accurate when the fractional current loss is small. We have performed circuit simulations of 52 Z experiments conducted with a variety of accelerator

  5. Three stage vacuum system for ultralow temperature installation

    NASA Astrophysics Data System (ADS)

    Das, N. K.; Pradhan, J.; Naser, Md Z. A.; Mandal, B. Ch; Roy, A.; Kumar, P.; Mallik, C.; Bhandari, R. K.

    2012-11-01

    We use a three stage vacuum system for developing a dilution fridge at VECC, Kolkata. We aim at achieving a cooling power of 20μW at 100mK for various experiments especially in the field of condensed matter and nuclear physics. The system is essentially composed of four segments-bath cryostat, vacuum system, dilution insert and 3He circulation circuit. Requirement of vacuum system at different stages are different. The vacuum system for cryostat and for internal vacuum chamber located within the helium bath is a common turbo molecular pump backed by scroll pump as to maintain a vacuum ~10-6mbar. For bringing down the temperature of the helium evaporator, we use a high throughput Roots pump backed by a dry pump. The pumping system for 3He distillation chamber (still) requires a high pumping speed, so a turbo drag pump backed by a scroll pump has been installed. As the fridge use precious 3He gas for operation, the entire system has been made to be absolutely leak proof with respect to the 3He gas.

  6. Generation of nanosecond neutron pulses in vacuum accelerating tubes

    NASA Astrophysics Data System (ADS)

    Didenko, A. N.; Shikanov, A. E.; Rashchikov, V. I.; Ryzhkov, V. I.; Shatokhin, V. L.

    2014-06-01

    The generation of neutron pulses with a duration of 1-100 ns using small vacuum accelerating tubes is considered. Two physical models of acceleration of short deuteron bunches in pulse neutron generators are described. The dependences of an instantaneous neutron flux in accelerating tubes on the parameters of pulse neutron generators are obtained using computer simulation. The results of experimental investigation of short-pulse neutron generators based on the accelerating tube with a vacuum-arc deuteron source, connected in the circuit with a discharge peaker, and an accelerating tube with a laser deuteron source, connected according to the Arkad'ev-Marx circuit, are given. In the experiments, the neutron yield per pulse reached 107 for a pulse duration of 10-100 ns. The resultant experimental data are in satisfactory agreement with the results of computer simulation.

  7. Solid state power controllers

    NASA Technical Reports Server (NTRS)

    Gibbs, R. S.

    1974-01-01

    Solid state power controllers (SSPC's) are to be considered for use as replacements of electromechanical relays and circuit breakers in future spacecraft and aircraft. They satisfy the combined function of both the relay and circuit breaker and can be remotely controlled by small signals, typically 10 mA, 5 to 28 v(dc). They have the advantage over conventional relay/circuit breaker systems in that they can be located near the utilization equipment and the primary ac or dc bus. The low level control, trip indication and status signals can be circuited by small gauge wire for control, computer interface, logic, electrical multiplexing, onboard testing, power management, and distribution purposes. This results in increased system versatility at appreciable weight saving and increased reliability. Conventional systems require the heavy gage load wiring and the control wiring to be routed from the bus to the load to other remote relay contacts, switches, sensors, etc. and to the circuit breaker located in the flight engineer's compartment for purposes of manual reset.

  8. 77 FR 16486 - Airworthiness Directives; Fokker Services B.V. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-21

    ... values of nuts on circuit breakers, contactors and terminal blocks of the EPC and battery relay panel... battery relay panel]. The required actions include doing a general visual inspection to determine if... and circuit breakers, contactors, and terminal blocks of the EPC and battery relay panel, as...

  9. 78 FR 21675 - Self-Regulatory Organizations; The NASDAQ Stock Market LLC; Order Approving, on an Accelerated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-11

    ... by significant amounts in a very short time period before suddenly reversing to prices consistent... circuit breaker pilot program, which was implemented through a series of rule filings by the equity exchanges and by FINRA.\\6\\ The single-stock circuit breaker was designed to reduce extraordinary market...

  10. Application Study of a High Temperature Superconducting Fault Current Limiter for Electric Power System

    NASA Astrophysics Data System (ADS)

    Naito, Yuji; Shimizu, Iwao; Yamaguchi, Iwao; Kaiho, Katsuyuki; Yanabu, Satoru

    Using high temperature superconductor, a Superconducting Fault Current Limiter (SFCL) was made and tested. Superconductor and vacuum interrupter as commutation switch are connected in parallel with bypass coil. When a fault occurs and the excessive current flows, superconductor is first quenched and the current is transferred to bypass coil because on voltage drop of superconductor. At the same time, since magnetic field is generated by current which flows in bypass coil, commutation switch is immediately driven by electromagnetic repulsion plate connected to driving rod of vacuum interrupter, and superconductor is separated from this circuit. Using the testing model, we could separate the superconductor from a circuit due to movement of vacuum interrupter within half-cycle current and transfer all current to bypass coil. Since operation of a commutation switch is included in current limiting operation of this testing model, it is one of helpful circuit of development of SFCL in the future. Moreover, since it can make the consumed energy of superconductor small during fault state due to realization of high-speed switch with simple composition, the burden of superconductor is reduced compared with conventional resistive type SFCL and it is considered that the flexibility of a SFCL design increases. Cooperation with a circuit breaker was also considered, the trial calculation of a parameter and energy of operation is conducted and discussion in the case of installing the SFCL to electric power system is made.

  11. 78 FR 21657 - Self-Regulatory Organizations; International Securities Exchange LLC; Order Approving, on an...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-11

    ... securities suddenly declining by significant amounts in a very short time period before suddenly reversing to... circuit breaker pilot program, which was implemented through a series of rule filings by the equity exchanges and by FINRA.\\9\\ The single-stock circuit breaker was designed to reduce extraordinary market...

  12. 78 FR 21642 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Order Granting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-11

    ... securities suddenly declining by significant amounts in a very short time period before suddenly reversing to... circuit breaker pilot program, which was implemented through a series of rule filings by the equity exchanges and by FINRA.\\8\\ The single-stock circuit breaker was designed to reduce extraordinary market...

  13. 46 CFR 111.54-3 - Remote control.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Remote control. 111.54-3 Section 111.54-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Circuit Breakers § 111.54-3 Remote control. Remotely controlled circuit breakers must have local...

  14. 46 CFR 111.54-3 - Remote control.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Remote control. 111.54-3 Section 111.54-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Circuit Breakers § 111.54-3 Remote control. Remotely controlled circuit breakers must have local...

  15. 46 CFR 111.54-3 - Remote control.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Remote control. 111.54-3 Section 111.54-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Circuit Breakers § 111.54-3 Remote control. Remotely controlled circuit breakers must have local...

  16. 46 CFR 111.54-3 - Remote control.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Remote control. 111.54-3 Section 111.54-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Circuit Breakers § 111.54-3 Remote control. Remotely controlled circuit breakers must have local...

  17. 46 CFR 111.54-3 - Remote control.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Remote control. 111.54-3 Section 111.54-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Circuit Breakers § 111.54-3 Remote control. Remotely controlled circuit breakers must have local...

  18. Resilience of the quantum Rabi model in circuit QED

    NASA Astrophysics Data System (ADS)

    E Manucharyan, Vladimir; Baksic, Alexandre; Ciuti, Cristiano

    2017-07-01

    In circuit quantum electrodynamics (circuit QED), an artificial ‘circuit atom’ can couple to a quantized microwave radiation much stronger than its real atomic counterpart. The celebrated quantum Rabi model describes the simplest interaction of a two-level system with a single-mode boson field. When the coupling is large enough, the bare multilevel structure of a realistic circuit atom cannot be ignored even if the circuit is strongly anharmonic. We explored this situation theoretically for flux (fluxonium) and charge (Cooper pair box) type multi-level circuits tuned to their respective flux/charge degeneracy points. We identified which spectral features of the quantum Rabi model survive and which are renormalized for large coupling. Despite significant renormalization of the low-energy spectrum in the fluxonium case, the key quantum Rabi feature—nearly-degenerate vacuum consisting of an atomic state entangled with a multi-photon field—appears in both types of circuits when the coupling is sufficiently large. Like in the quantum Rabi model, for very large couplings the entanglement spectrum is dominated by only two, nearly equal eigenvalues, in spite of the fact that a large number of bare atomic states are actually involved in the atom-resonator ground state. We interpret the emergence of the two-fold degeneracy of the vacuum of both circuits as an environmental suppression of flux/charge tunneling due to their dressing by virtual low-/high-impedance photons in the resonator. For flux tunneling, the dressing is nothing else than the shunting of a Josephson atom with a large capacitance of the resonator. Suppression of charge tunneling is a manifestation of the dynamical Coulomb blockade of transport in tunnel junctions connected to resistive leads.

  19. 75 FR 22043 - Airworthiness Directives; Agusta S.p.A. (Agusta) Model A109E Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-27

    ... report of an electrical failure, an investigation revealed inadequate functioning of the 35 amperes (Amps... to replace the 35 Amps with a 50 Amps circuit breaker and replace the wires with oversized ones to... of the 35 Amps BATT BUS circuit breaker. To prevent an electrical failure, the manufacturer has...

  20. Use of vacuum tubes in test instrumentation for measuring characteristics of fast high-voltage semiconductor devices

    NASA Technical Reports Server (NTRS)

    Berning, D.

    1981-01-01

    Circuits are described that permit measurement of fast events occurring in power semiconductors. These circuits were developed for the dynamic characterization of transistors used in inductive-load switching applications. Fast voltage clamping using vacuum diodes is discussed, and reference is made to a unique circuit that was built for performing nondestructive, reverse-bias, second-breakdown tests on transistors.

  1. Vacuum Gap Microstrip Microwave Resonators for 2.5-D Integration in Quantum Computing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lewis, Rupert M.; Henry, Michael David; Schroeder, Katlin

    We demonstrate vacuum gap λ/2 microwave resonators as a route toward higher integration in superconducting qubit circuits. The resonators are fabricated from pieces on two silicon chips bonded together with an In-Sb bond. Measurements of the devices yield resonant frequencies in good agreement with simulations. Furthermore, we discuss creating low loss circuits in this geometry.

  2. Vacuum Gap Microstrip Microwave Resonators for 2.5-D Integration in Quantum Computing

    DOE PAGES

    Lewis, Rupert M.; Henry, Michael David; Schroeder, Katlin

    2017-02-22

    We demonstrate vacuum gap λ/2 microwave resonators as a route toward higher integration in superconducting qubit circuits. The resonators are fabricated from pieces on two silicon chips bonded together with an In-Sb bond. Measurements of the devices yield resonant frequencies in good agreement with simulations. Furthermore, we discuss creating low loss circuits in this geometry.

  3. 78 FR 56601 - Airworthiness Directives; Fokker Services B.V. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-13

    ... torque values of nuts on circuit breakers, contactors, and terminal blocks of the EPC and battery relay... blocks of the EPC and battery relay panel, as applicable; and do all applicable adjustments of the torque... contacts and nuts on circuit breakers, contactors, and terminal blocks of the EPC and battery relay panel...

  4. Increasing the open-circuit voltage of photoprotein-based photoelectrochemical cells by manipulation of the vacuum potential of the electrolytes.

    PubMed

    Tan, Swee Ching; Crouch, Lucy I; Mahajan, Sumeet; Jones, Michael R; Welland, Mark E

    2012-10-23

    The innately highly efficient light-powered separation of charge that underpins natural photosynthesis can be exploited for applications in photoelectrochemistry by coupling nanoscale protein photoreaction centers to man-made electrodes. Planar photoelectrochemical cells employing purple bacterial reaction centers have been constructed that produce a direct current under continuous illumination and an alternating current in response to discontinuous illumination. The present work explored the basis of the open-circuit voltage (V(OC)) produced by such cells with reaction center/antenna (RC-LH1) proteins as the photovoltaic component. It was established that an up to ~30-fold increase in V(OC) could be achieved by simple manipulation of the electrolyte connecting the protein to the counter electrode, with an approximately linear relationship being observed between the vacuum potential of the electrolyte and the resulting V(OC). We conclude that the V(OC) of such a cell is dependent on the potential difference between the electrolyte and the photo-oxidized bacteriochlorophylls in the reaction center. The steady-state short-circuit current (J(SC)) obtained under continuous illumination also varied with different electrolytes by a factor of ~6-fold. The findings demonstrate a simple way to boost the voltage output of such protein-based cells into the hundreds of millivolts range typical of dye-sensitized and polymer-blend solar cells, while maintaining or improving the J(SC). Possible strategies for further increasing the V(OC) of such protein-based photoelectrochemical cells through protein engineering are discussed.

  5. 48 CFR 212.301 - Solicitation provisions and contract clauses for the acquisition of commercial items.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Offers for Air Circuit Breakers, as prescribed in 225.7006-4(a), to comply with 10 U.S.C. 2534(a)(3). (xxxvii) Use the clause at 252.225-7038, Restriction on Acquisition of Air Circuit Breakers, as prescribed...(c). (xlv) Use the clause at 252.232-7003, Electronic Submission of Payment Requests and Receiving...

  6. Building Community in the Classroom through Ice-Breakers and Parting Ways

    ERIC Educational Resources Information Center

    Eggleston, Tami; Smith, Gabie

    2004-01-01

    Many instructors are concerned with creating a community in the classroom. Although there are numerous published "ice-breakers," many of these techniques are not specific to psychology courses or have been used so much that the students see them as redundant and cliche. Icebreakers are better if they have relevance to a specific class, are…

  7. Development of 72/84kV Dry Air Insulated Dead Tank Type VCB

    NASA Astrophysics Data System (ADS)

    Saito, Hitoshi; Nagatake, Kazuhiro; Komatsu, Hideki; Takeshita, Yukihiro; Matsui, Yoshihiko; Katsumata, Kiyohito; Sakaki, Masayuki

    As a circuit breaker for over 84kV, SF6 gas circuit breaker (GCB) has been used for a long time, in virtue of its excellent characteristics as arc extinction and insulating medium. Although, SF6 gas has very high global warming potential (GWP) of 23,900, and it was designated to regulation object in COP3 in Kyoto in 1997. A lot of efforts have been done to reduce the amount of SF6 gas usage and emission from conventional equipments. On the other hand, SF6 gas free equipment has been researching and one strong candidate is air-insulated type switchgears with vacuum interrupters. In last few years, air-insulated switchgears, which include GIS, Cubicle type GIS (C-GIS) and dead tank type VCB, have been developed in succession. So far, we have already more than three years operation record for the air-insulated dead tank type VCB, and over 100 units is in-service in power systems. Recently, VCB technology, that is essential for SF6 gas-free equipments, has been advanced in the field of high-voltage, large current interruption and environment-conscious design. In this paper, the advanced dead tank type VCB and its technology is descried.

  8. Circuit board routing attachment for Fermilab Gerber plotter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lindenmeyer, C.

    1984-05-10

    A new and potentially important method of producing large circuit boards has been developed at Fermilab. A Gerber Flat Bed Plotter with an active area of 5' x 16' has been fitted with a machining head to produce a circuit board without the use of photography or chemicals. The modifications of the Gerber Plotter do not impair its use as a photoplotter or pen plotter, the machining head is merely exchanged with the standard attachments. The modifications to the program are minimal; this will be described in another report. The machining head is fitted with an air bearing motorized spindlemore » driven at a speed of 40,000 rpm to 90,000 rpm. The spindle also is provided with air bearings on its outside diameter, offering frictionless vertical travel guidance. Vertical travel of the spindle is driven by a spring return single acting air cylinder. An adjustable hydraulic damper slows the spindle travel near the end of its downward stroke. Two programmable stops control spindle down stroke position, and limit switches are provided for position feedback to the control system. A vacuum system collects chips at the cutter head. No lubrication or regular maintenance is required. The circuit board to be fabricated is supported on a porous plastic mat which allows table vacuum to hold the board in place while allowing the cutters or drills to cut through the board without damaging the rubber platen of the plotter. The perimeter of the board must be covered to the limits of the table vacuum area used to prevent excessive leakage.« less

  9. Paper-based silver-nanowire electronic circuits with outstanding electrical conductivity and extreme bending stability.

    PubMed

    Huang, Gui-Wen; Xiao, Hong-Mei; Fu, Shao-Yun

    2014-08-07

    Here a facile, green and efficient printing-filtration-press (PFP) technique is reported for room-temperature (RT) mass-production of low-cost, environmentally friendly, high performance paper-based electronic circuits. The as-prepared silver nanowires (Ag-NWs) are uniformly deposited at RT on a pre-printed paper substrate to form high quality circuits via vacuum filtration and pressing. The PFP circuit exhibits more excellent electrical property and bending stability compared with other flexible circuits made by existing techniques. Furthermore, practical applications of the PFP circuits are demonstrated.

  10. Reconfigurable liquid metal circuits by Laplace pressure shaping

    NASA Astrophysics Data System (ADS)

    Cumby, Brad L.; Hayes, Gerard J.; Dickey, Michael D.; Justice, Ryan S.; Tabor, Christopher E.; Heikenfeld, Jason C.

    2012-10-01

    We report reconfigurable circuits formed by liquid metal shaping with <10 pounds per square inch (psi) Laplace and vacuum pressures. Laplace pressure drives liquid metals into microreplicated trenches, and upon release of vacuum, the liquid metal dewets into droplets that are compacted to 10-100× less area than when in the channel. Experimental validation includes measurements of actuation speeds exceeding 30 cm/s, simple erasable resistive networks, and switchable 4.5 GHz antennas. Such capability may be of value for next generation of simple electronic switches, tunable antennas, adaptive reflectors, and switchable metamaterials.

  11. Kinetic Studies of Inhibition of the Aβ(1–42) Aggregation Using a Ferrocene-tagged β-Sheet Breaker Peptide

    PubMed Central

    Zhang, Lin; Yagnik, Gargey; Peng, Yong; Wang, Jianxiu; Xu, H. Howard; Hao, Yuanqiang; Liu, You-Nian; Zhou, Feimeng

    2013-01-01

    The aggregation of amyloidogenic proteins/peptides has been closely linked to the neuropathology of several important neurological disorders. In Alzheimer's disease (AD), amyloid beta (Aβ) peptides and their aggregation are believed to be at least partially responsible for the etiology of AD. The aggregate-inflicted cellular toxicity can be inhibited by short peptides whose sequence are homologous to segments of the Aβ(1–42) peptide responsible for β-sheet stacking (referred to as the β-sheet breaker peptides). Herein a water-soluble ferrocene (Fc)-tagged β-sheet breaker peptide (Fc-KLVFFK6) is used as an electrochemical probe for kinetic studies of the inhibition of the Aβ(1–42) fibrillation process and for determination of the optimal concentration of β-sheet breaker peptide for efficient inhibition. Our results demonstrated that Fc-KLVFFK6 interacts with the Aβ aggregates instantaneously in solution, and sub-stoichiometric amount of Fc-KLVFFK6 is sufficient to inhibit the formation of the Aβ oligomers and fibrils and to reduce the toxicity of Aβ(1–42). The interaction between Fc-KLVFFK6 and Aβ(1–42) follows a pseudo-first-order reaction, with a rate constant of 1.89 ± 0.05 × 10−4 s−1. Tagging β-sheet breaker peptides with a redox label facilitates design, screening, and rational use of peptidic inhibitors for impeding/altering Aβ aggregation. PMID:23232068

  12. RF Frequency Oscillations in the Early Stages of Vacuum Arc Collapse

    NASA Technical Reports Server (NTRS)

    Griffin, Steven T.; Thio, Y. C. Francis

    2003-01-01

    RF frequency oscillations may be produced in a typical capacitive charging / discharging pulsed power system. These oscillations may be benign, parasitic, destructive or crucial to energy deposition. In some applications, proper damping of oscillations may be critical to proper plasma formation. Because the energy deposited into the plasma is a function of plasma and circuit conditions, the entire plasma / circuit system needs to be considered as a unit To accomplish this, the initiation of plasma is modeled as a time-varying, non-linear element in a circuit analysis model. The predicted spectra are compared to empirical power density spectra including those obtained from vacuum arcs.

  13. Enhanced rhamnolipids production via efficient foam-control using stop valve as a foam breaker.

    PubMed

    Long, Xuwei; Shen, Chong; He, Ni; Zhang, Guoliang; Meng, Qin

    2017-01-01

    In this study, a stop valve was used as a foam breaker for dealing with the massive overflowing foam in rhamnolipid fermentation. As found, a stop valve at its tiny opening could break over 90% of the extremely stable rhamnolipid foam into enriched liquid when foam flows through the sharp gap in valve. The efficient foam-control by the stop valve considerably improved the rhamnolipid fermentation and significantly enhanced the rhamnolipid productivity by 83% compared to the regular fermentation. This efficient foam breaking was mainly achieved by a high shear rate in combination with fast separation of air from the collapsed foam. Altogether, the stop valve possessed a great activity in breaking rhamnolipid foam, and the involving mechanism holds the potential for developing efficient foam breakers for industrial rhamnolipid fermentation. Copyright © 2016. Published by Elsevier Ltd.

  14. An assessment of the hardness of miniature vacuum tubes to high-voltage transients

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Orvis, W.J.

    1990-03-01

    Miniature vacuum tubes are vacuum switching and control devices fabricated on a silicon wafer, using the same technology as is used to make integrated circuits. They operate in much the same manner as conventional vacuum tubes, but with two important differences: they are micron sized devices, and they employ field emission instead of thermionic emission as the electron source. As these devices have a vacuum as their active region, they will be extremely hard to nuclear radiation and relatively insensitive to temperature effects, they are also expected to be extremely fast devices. We have estimated here that their hardness tomore » high-voltage transients will be at least as good as existing semiconductor devices and possibly better. 5 figs.« less

  15. Vacuum Microelectronic Field Emission Array Devices for Microwave Amplification.

    NASA Astrophysics Data System (ADS)

    Mancusi, Joseph Edward

    This dissertation presents the design, analysis, and measurement of vacuum microelectronic devices which use field emission to extract an electron current from arrays of silicon cones. The arrays of regularly-spaced silicon cones, the field emission cathodes or emitters, are fabricated with an integrated gate electrode which controls the electric field at the tip of the cone, and thus the electron current. An anode or collector electrode is placed above the array to collect the emission current. These arrays, which are fabricated in a standard silicon processing facility, are developed for use as high power microwave amplifiers. Field emission has been studied extensively since it was first characterized in 1928, however due to the large electric fields required practical field emission devices are difficult to make. With the development of the semiconductor industry came the development of fabrication equipment and techniques which allow for the manufacture of the precision micron-scale structures necessary for practical field emission devices. The active region of a field emission device is a vacuum, therefore the electron travel is ballistic. This analysis of field emission devices includes electric field and electron emission modeling, development of a device equivalent circuit, analysis of the parameters in the equivalent circuit, and device testing. Variations in device structure are taken into account using a statistical model based upon device measurements. Measurements of silicon field emitter arrays at DC and RF are presented and analyzed. In this dissertation, the equivalent circuit is developed from the analysis of the device structure. The circuit parameters are calculated from geometrical considerations and material properties, or are determined from device measurements. It is necessary to include the emitter resistance in the equivalent circuit model since relatively high resistivity silicon wafers are used. As is demonstrated, the circuit model

  16. Push-pull radio frequency circuit with integral transistion to waveguide output

    DOEpatents

    Bennett, Wilfred P.

    1987-01-01

    A radio frequency circuit for ICRF heating includes a resonant push-pull circuit, a double ridged rectangular waveguide, and a coupling transition which joins the waveguide to the resonant circuit. The resonant circuit includes two cylindrical conductors mounted side by side and two power vacuum tubes attached to respective ends of a cylindrical conductor. A conductive yoke is located at the other end of the cylindrical conductors to short circuit the two cylindrical conductors. The coupling transition includes two relatively flat rectangular conductors extending perpendicular to the longitudinal axes of a respective cylindrical conductor to which the flat conductor is attached intermediate the ends thereof. Conductive side covers and end covers are also provided for forming pockets in the waveguide into which the flat conductors extend when the waveguide is attached to a shielding enclosure surrounding the resonant circuit.

  17. Suppressing breakers with polar oil films: Using an epic sea rescue to model wave energy budgets

    NASA Astrophysics Data System (ADS)

    Cox, Charles S.; Zhang, Xin; Duda, Timothy F.

    2017-02-01

    Oil has been used to still stormy seas for centuries, but the mechanisms are poorly understood. Here we examine the processes by using quantitative information from a remarkable 1883 sea rescue where oil was used to reduce large breakers during a storm. Modeling of the oil film's extent and waves under the film suggests that large breakers were suppressed by a reduction of wind energy input. Modification of surface roughness by the film is hypothesized to alter the wind profile above the sea and the energy flow. The results are central to understanding air-sea momentum exchange, including its role in such processes as cyclone growth and storm surge, although they address only one aspect of the complex problem of wind interaction with the ocean surface.

  18. Solid state power controllers

    NASA Technical Reports Server (NTRS)

    Gibbs, R. S.

    1973-01-01

    The rationale, analysis, design, breadboarding and testing of the incremental functional requirements are reported that led to the development of prototype 1 and 5 Amp dc and 1 Amp ac solid state power controllers (SSPC's). The SSPC's are to be considered for use as a replacement of electro-mechanical relays and circuit breakers in future spacecraft and aircraft. They satisfy the combined function of both the relay and circuit breaker and can be remotely controlled by small signals, typically 10 mA, 5 to 28 Vdc. They have the advantage over conventional relay/circuit breaker systems in that they can be located near utilization equipment and the primary ac or dc bus. The low level control, trip indication and status signals can be circuited by small guage wire for control, computer interface, logic, electrical multiplexing, unboard testing, and power management and distribution purposes. This results in increased system versatility at appreciable weight saving and increased reliability.

  19. 46 CFR 54.01-40 - External pressure (modifies UG-28).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... at times be subjected to partial vacuum due to nature of the contents, temperature, unloading operations, or other facet of employment shall either have vacuum breaker protection or be designed for not...

  20. 46 CFR 54.01-40 - External pressure (modifies UG-28).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... at times be subjected to partial vacuum due to nature of the contents, temperature, unloading operations, or other facet of employment shall either have vacuum breaker protection or be designed for not...

  1. 46 CFR 54.01-40 - External pressure (modifies UG-28).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... at times be subjected to partial vacuum due to nature of the contents, temperature, unloading operations, or other facet of employment shall either have vacuum breaker protection or be designed for not...

  2. 46 CFR 54.01-40 - External pressure (modifies UG-28).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... at times be subjected to partial vacuum due to nature of the contents, temperature, unloading operations, or other facet of employment shall either have vacuum breaker protection or be designed for not...

  3. 46 CFR 54.01-40 - External pressure (modifies UG-28).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... at times be subjected to partial vacuum due to nature of the contents, temperature, unloading operations, or other facet of employment shall either have vacuum breaker protection or be designed for not...

  4. Fundamental Insulation Characteristics of Air, N2, CO2, N2/O2 and SF6/N2 Mixed Gases

    NASA Astrophysics Data System (ADS)

    Rokunohe, Toshiaki; Yagihashi, Yoshitaka; Endo, Fumihiro; Oomori, Takashi

    SF6 gas has excellent dielectric strength and interruption performance. For these reasons, it has been widely used for gas insulated switchgear (GIS). However, use of SF6 gas has become regulated under agreements set at the 1997 COP3. Presently, development of a gas circuit breaker (GCB) using CO2 gas and development of a high voltage vacuum circuit breaker (VCB) are being pursued. GIS consists of disconnectors (DS), earthing switches (ES) and buses in addition to GCB. Since the interruption performance is not an important requirement for DS, ES and BUS, use of a gas with high dielectric strength is better than use of a gas with good interruption performance. Air and N2 are not greenhouse gases, and their dielectric strengths are higher than those of other SF6 alternative gases, but only about one-third of the dielectric strength of SF6 gas. This paper deals with a suitable insulation gas which has no greenhouse effect as an SF6 alternative gas. The N2/O2 mixed gas was investigated by changing the ratio of O2. Moreover, the effect of an insulation coating was investigated and compared with the dielectric strength of SF6/N2 mixed gas. The dielectric strength of air under the coating condition was equal to that of 10%SF6/N2 mixed gas.

  5. Performance of red pine and Japanese larch planted on anthracite coal-breaker refuse

    Treesearch

    Miroslaw M. Czapowskyj

    1973-01-01

    Red pine (Pinus resinosa Ait.) and Japanese larch (Larix leptolepis (Sieb. and Zucc.) Gord.) seedlings were planted on coal-breaker refuse with all combinations of two levels of lime, two levels of fertilizer, and four mulch treatments. The site was highly unfavorable as a medium for tree growth, and the 4-year results show...

  6. Comparative simulation of switching regimes of magnetic explosion generators by copper and aluminum magnetodynamic current breakers taking into account elastoplastic properties of materials

    NASA Astrophysics Data System (ADS)

    Bazanov, A. A.; Ivanovskii, A. V.; Panov, A. I.; Samodolov, A. V.; Sokolov, S. S.; Shaidullin, V. Sh.

    2017-06-01

    We report on the results of the computer simulation of the operation of magnetodynamic break switches used as the second stage of current pulse formation in magnetic explosion generators. The simulation was carried out under the conditions when the magnetic field energy density on the surface of the switching conductor as a function of the current through it was close to but still did not exceed the critical value typical of the beginning of electric explosion. In the computational model, we used the parameters of experimentally tested sample of a coil magnetic explosion generator that can store energy of up to 2.7 MJ in the inductive storage circuit and equipped with a primary explosion stage of the current pulse formation. It has been shown that the choice of the switching conductor material, as well as its elastoplastic properties, considerably affects the breaker speed. Comparative results of computer simulation for copper and aluminum have been considered.

  7. KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician (left) looks at the circuit breaker lights in the cabin. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

    NASA Image and Video Library

    2003-08-27

    KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician (left) looks at the circuit breaker lights in the cabin. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

  8. Irradiation and measurements of fluorinated ethylene-propylene-A on silicon solar cells in vacuum

    NASA Technical Reports Server (NTRS)

    Marsik, S. J.; Broder, J. D.

    1975-01-01

    Silicon monoxide (SiO) coated silicon solar cells covered with fluorinated ethylene-propylene-A (FEP-A) were irradiated by 1-MeV electrons in vacuum. The effect of irradiation on the light transmittance of FEP-A was checked by measuring the short-circuit current of the cells while in vacuum after each dose increment, immediately after the irradiation, and again after a minimum elapsed time of 16 hr. The results indicated no apparent loss in transmission due to irradiation of FEP-A and no delamination from the SiO surface while the cells were in vacuum, but embrittlement of FEP-A occurred at the accumulated dose.

  9. [Work accidents and automatic circuit reclosers in the electricity sector: beyond the immediate causes].

    PubMed

    Silva, Alessandro Jose Nunes da; Almeida, Ildeberto Muniz de; Vilela, Rodolfo Andrade de Gouveia; Mendes, Renata Wey Berti; Hurtado, Sandra Lorena Beltran

    2018-05-10

    The Brazilian electricity sector has recorded high work-related mortality rates that have been associated with outsourcing, used to cut costs. In order to decrease the power outage time for consumers, the industry adopted the automatic circuit recloser as the technical solution. The device has hazardous implications for maintenance workers. The aim of this study was to analyze the origins and consequences of work accidents in power systems with automatic circuit recloser, using the Accident Analysis and Prevention (AAP) model. The AAP model was used to investigate two work accidents, aimed to explore the events' organizational origins. Case 1 - when changing a deenergized secondary line, a worker received a shock from the energized primary cable (13.8kV). The system reclosed three times, causing severe injury to the worker (amputation of a lower limb). Case 2 - a fatal work accident occurred during installation of a new crosshead on a partially insulated energized line. The tip of a metal cross arm section strap touched the energized secondary line and electrocuted the maintenance operator. The circuit breaker component of the automatic circuit recloser failed. The analyses revealed how business management logic can participate in the root causes of work accidents through failures in maintenance management, outsourced workforce management, and especially safety management in systems with reclosers. Decisions to adopt automation to guarantee power distribution should not overlook the risks to workers in overhead power lines or fail to acknowledge the importance of ensuring safe conditions.

  10. Method of forming ultra thin film devices by vacuum arc vapor deposition

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F. (Inventor)

    2005-01-01

    A method for providing an ultra thin electrical circuit integral with a portion of a surface of an object, including using a focal Vacuum Arc Vapor Deposition device having a chamber, a nozzle and a nozzle seal, depressing the nozzle seal against the portion of the object surface to create an airtight compartment in the chamber and depositing one or more ultra thin film layer(s) only on the portion of the surface of the object, the layers being of distinct patterns such that they form the circuit.

  11. Wafer-Level Vacuum Packaging of Smart Sensors.

    PubMed

    Hilton, Allan; Temple, Dorota S

    2016-10-31

    The reach and impact of the Internet of Things will depend on the availability of low-cost, smart sensors-"low cost" for ubiquitous presence, and "smart" for connectivity and autonomy. By using wafer-level processes not only for the smart sensor fabrication and integration, but also for packaging, we can further greatly reduce the cost of sensor components and systems as well as further decrease their size and weight. This paper reviews the state-of-the-art in the wafer-level vacuum packaging technology of smart sensors. We describe the processes needed to create the wafer-scale vacuum microchambers, focusing on approaches that involve metal seals and that are compatible with the thermal budget of complementary metal-oxide semiconductor (CMOS) integrated circuits. We review choices of seal materials and structures that are available to a device designer, and present techniques used for the fabrication of metal seals on device and window wafers. We also analyze the deposition and activation of thin film getters needed to maintain vacuum in the ultra-small chambers, and the wafer-to-wafer bonding processes that form the hermetic seal. We discuss inherent trade-offs and challenges of each seal material set and the corresponding bonding processes. Finally, we identify areas for further research that could help broaden implementations of the wafer-level vacuum packaging technology.

  12. Wafer-Level Vacuum Packaging of Smart Sensors

    PubMed Central

    Hilton, Allan; Temple, Dorota S.

    2016-01-01

    The reach and impact of the Internet of Things will depend on the availability of low-cost, smart sensors—“low cost” for ubiquitous presence, and “smart” for connectivity and autonomy. By using wafer-level processes not only for the smart sensor fabrication and integration, but also for packaging, we can further greatly reduce the cost of sensor components and systems as well as further decrease their size and weight. This paper reviews the state-of-the-art in the wafer-level vacuum packaging technology of smart sensors. We describe the processes needed to create the wafer-scale vacuum microchambers, focusing on approaches that involve metal seals and that are compatible with the thermal budget of complementary metal-oxide semiconductor (CMOS) integrated circuits. We review choices of seal materials and structures that are available to a device designer, and present techniques used for the fabrication of metal seals on device and window wafers. We also analyze the deposition and activation of thin film getters needed to maintain vacuum in the ultra-small chambers, and the wafer-to-wafer bonding processes that form the hermetic seal. We discuss inherent trade-offs and challenges of each seal material set and the corresponding bonding processes. Finally, we identify areas for further research that could help broaden implementations of the wafer-level vacuum packaging technology. PMID:27809249

  13. Controlling Photons, Qubits and their Interactions in Superconducting Electronic Circuits

    NASA Astrophysics Data System (ADS)

    Wallraff, Andreas

    2009-03-01

    A combination of ideas from atomic physics, quantum optics and solid state physics allows us to investigate the fundamental interaction of matter and light on the level of single quanta in electronic circuits. In an approach known as circuit quantum electrodynamics, we coherently couple individual photons stored in a high quality microwave frequency resonator to a fully controllable superconducting two-level system (qubit) realized in a macroscopic electronic circuit [1]. In particular, we have recently observed the simultaneous interaction of one, two and three photons with a single qubit. In these experiments, we have probed the quantum nonlinearity of the qubit/light interaction governed by the Jaynes-Cummings hamiltonian, clearly demonstrating the quantization of the radiation field in the on-chip cavity. We have also performed quantum optics experiments with no photons at all. In this situation, i.e. in pure vacuum, we have resolved the renormalization of the qubit transition frequency - known as the Lamb shift - due to its non-resonant interaction with the cavity vacuum fluctuations [3].[4pt] [1] A. Wallraff et al., Nature (London) 431, 162 (2004)[0pt] [2] J. Fink et al., Nature (London) 454, 315 (2008)[0pt] [3] A. Fragner et al., Science 322, 1357 (2008)

  14. Material-controlled dynamic vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1996-10-08

    A compact vacuum insulation panel is described comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber includes apparatus and methods for enabling and disabling, or turning ``on`` and ``off`` the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls. 25 figs.

  15. Material-controlled dynamic vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1996-10-08

    A compact vacuum insulation panel comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber includes apparatus and methods for enabling and disabling, or turning "on" and "off" the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls.

  16. Radiation-controlled dynamic vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1995-01-01

    A compact vacuum insulation panel comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber that includes apparatus and methods for enabling and disabling, or turning "on" and "off" the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls.

  17. Radiation-controlled dynamic vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1995-07-18

    A compact vacuum insulation panel is described comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber that includes apparatus and methods for enabling and disabling, or turning ``on`` and ``off`` the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls. 25 figs.

  18. Vacuum arc plasma thrusters with inductive energy storage driver

    NASA Technical Reports Server (NTRS)

    Schein, Jochen (Inventor); Gerhan, Andrew N. (Inventor); Woo, Robyn L. (Inventor); Au, Michael Y. (Inventor); Krishnan, Mahadevan (Inventor)

    2004-01-01

    An apparatus for producing a vacuum arc plasma source device using a low mass, compact inductive energy storage circuit powered by a low voltage DC supply acts as a vacuum arc plasma thruster. An inductor is charged through a switch, subsequently the switch is opened and a voltage spike of Ldi/dt is produced initiating plasma across a resistive path separating anode and cathode. The plasma is subsequently maintained by energy stored in the inductor. Plasma is produced from cathode material, which allows for any electrically conductive material to be used. A planar structure, a tubular structure, and a coaxial structure allow for consumption of cathode material feed and thereby long lifetime of the thruster for long durations of time.

  19. Hybrid Circuit QED with Electrons on Helium

    NASA Astrophysics Data System (ADS)

    Yang, Ge

    Electrons on helium (eHe) is a 2-dimensional system that forms naturally at the interface between superfluid helium and vacuum. It has the highest measured electron mobility, and long predicted spin coherence time. In this talk, we will first review various quantum computer architecture proposals that take advantage of these exceptional properties. In particular, we describe how electrons on helium can be combined with superconducting microwave circuits to take advantage of the recent progress in the field of circuit quantum electrodynamics (cQED). We will then demonstrate how to reliably trap electrons on these devices hours at a time, at millikelvin temperatures inside a dilution refrigerator. The coupling between the electrons and the microwave resonator exceeds 1 MHz, and can be reproduced from the design geometry using our numerical simulation. Finally, we will present our progress on isolating individual electrons in such circuits, to build single-electron quantum dots with electrons on helium.

  20. 30 CFR 75.508 - Map of electrical system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... apparatus in connection with the mine electric system, including permanent cables, switchgear, rectifying... direct-current circuit breakers protecting underground trolley circuits, shall be shown on a mine map...

  1. 30 CFR 75.508 - Map of electrical system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... apparatus in connection with the mine electric system, including permanent cables, switchgear, rectifying... direct-current circuit breakers protecting underground trolley circuits, shall be shown on a mine map...

  2. Effect of Vacuum on Venous Drainage: an Experimental Evaluation on Pediatric Venous Cannulas and Tubing Systems.

    PubMed

    Vida, V L; Bhattarai, A; Speggiorin, S; Zanella, F; Stellin, G

    2014-01-01

    To observe how vacuum assisted venous drainage (VAVD) may influence the flow in a cardiopulmonary bypass circuit with different size of venous lines and cannulas. The experimental circuit was assembled to represent the cardiopulmonary bypass circuit routinely used during cardiac surgery. Wall suction was applied directly, modulated and measured into the venous reservoir. The blood flow was measured with a flow-meter positioned on the venous line. The circuit prime volume was replaced with group O date expired re-suspended red cells and Plasmalyte 148 to a hematocrit of 28% to 30%. In an open circuit with gravity siphon venous drain, angled cannulae drain more than straight ones regardless the amount of suction applied to the venous line (16 Fr straight cannula (S) drains 90 ml/min less than a 16 Fr angled (A) with a siphon gravity). The same flow can be obtained with lower cannula size and higher suction (i.e. 12 A with and -30 mmHg). Tables have been created to list how the flow varies according to the size of the cannulas, the size of the venous tubes, and the amount of suction applied to the system. Vacuum assisted venous drainage allows the use of smaller cannulae and venous lines to maintain a good venous return, which is very useful during minimally invasive approaches. The present study should be considered as a preliminary attempt to create a scientific-based starting point for a uniform the use of VAVD.

  3. 17 CFR 242.201 - Circuit breaker.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) The term covered security shall mean any NMS stock as defined in § 242.600(b)(47). (2) The term effective transaction reporting plan for a covered security shall have the same meaning as in § 242.600(b... shall have the same meaning as in § 242.600(b)(42). (5) The term odd lot shall have the same meaning as...

  4. 17 CFR 242.201 - Circuit breaker.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) The term covered security shall mean any NMS stock as defined in § 242.600(b)(47). (2) The term effective transaction reporting plan for a covered security shall have the same meaning as in § 242.600(b... shall have the same meaning as in § 242.600(b)(42). (5) The term odd lot shall have the same meaning as...

  5. 17 CFR 242.201 - Circuit breaker.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) The term covered security shall mean any NMS stock as defined in § 242.600(b)(47). (2) The term effective transaction reporting plan for a covered security shall have the same meaning as in § 242.600(b... shall have the same meaning as in § 242.600(b)(42). (5) The term odd lot shall have the same meaning as...

  6. 17 CFR 242.201 - Circuit breaker.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) The term covered security shall mean any NMS stock as defined in § 242.600(b)(47). (2) The term effective transaction reporting plan for a covered security shall have the same meaning as in § 242.600(b... shall have the same meaning as in § 242.600(b)(42). (5) The term odd lot shall have the same meaning as...

  7. Laser-induced electron source in a vacuum diode

    NASA Astrophysics Data System (ADS)

    Ghera, U.; Boxman, R. L.; Kleinman, H.; Ruschin, S.

    1989-11-01

    Experiments were conducted in which a high-power CO2 TEA laser interacted with metallic cathode in a high-vacuum (10 to the -8th Torr) diode. For power densities lower than 5 x 10 to the 7th W/sq cm, no current was detected. For power densities in the range of 5 x 10 to the 7th to 5 x 10 to the 8th W/sq cm, the Cu cathode emitted a maximum current of 40 mA. At a higher power density level, a circuit-limited current of 8 A was detected. The jump of a few orders of magnitude in the current is attributed to breakdown of the diode gap. The experimental results are similar to those of a triggered vacuum gap, and a thorough comparison is presented in this paper. The influence of the pressure in the vacuum chamber on the current magnitude shows the active role that adsorbed gas molecules have in the initial breakdown. When the cathode material was changed from metal to metal oxide, much lower laser power densities were required to reach the breakdown current region.

  8. A superconducting direct-current limiter with a power of up to 8 MVA

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fisher, L. M.; Alferov, D. F., E-mail: DFAlferov@niitfa.ru; Akhmetgareev, M. R.

    2016-12-15

    A resistive switching superconducting fault current limiter (SFCL) for DC networks with a nominal voltage of 3.5 kV and a nominal current of 2 kA was developed, produced, and tested. The SFCL has two main units—an assembly of superconducting modules and a high-speed vacuum circuit breaker. The assembly of superconducting modules consists of nine (3 × 3) parallel–series connected modules. Each module contains four parallel-connected 2G high-temperature superconducting (HTS) tapes. The results of SFCL tests in the short-circuit emulation mode with a maximum current rise rate of 1300 A/ms are presented. The SFCL is capable of limiting the current atmore » a level of 7 kA and break it 8 ms after the current-limiting mode begins. The average temperature of HTS tapes during the current-limiting mode increases to 210 K. After the current is interrupted, the superconductivity recovery time does not exceed 1 s.« less

  9. High-voltage, high-power, solid-state remote power controllers for aerospace applications

    NASA Technical Reports Server (NTRS)

    Sturman, J. C.

    1985-01-01

    Two general types of remote power controller (RPC) that combine the functions of a circuit breaker and a switch were developed for use in direct-current (dc) aerospace systems. Power-switching devices used in these designs are the relatively new gate-turnoff thyristor (GTO) and poweer metal-oxide-semiconductor field-effect transistors (MOSFET). The various RPC's can switch dc voltages to 1200 V and currents to 100 A. Seven different units were constructed and subjected to comprehensive laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times to limit voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout and microsecond tripout for large overloads. The basic circuits developed can be used to build switchgear limited only by the ratings of the switching device used.

  10. Analysis of switching surges generated by current interruption in an energy-storge coil

    NASA Astrophysics Data System (ADS)

    Chowdhuri, P.

    1981-10-01

    The transient voltages which are generated when the current in a large magnetic energy storage coil is interruped by a dc vacuum circuit breaker is analyzed. The effect of the various parameters in the circuit on the transient voltage is dicussed. The self inductance of the dump resistor must be minimized to control the generated transient. Contrary to general belief, a capacitor across the coil is not an effective surge suppressor. In fact, the capacitor may excite oscillations of higher magnitude. However, a capacitor, in addition to a surge suppressor, may be used to modify the frequency components of the transient voltage so that these frequency components are not coincident with the natural frequencies of the coil. Otherwise, resonant oscillations inside the coil may attain damaging magnitudes. The capacitor would also reduce the steepness of the wavefront of the transient across the coil, thus reducing the nonlinear voltage distribution inside the coil.

  11. A superconducting direct-current limiter with a power of up to 8 MVA

    NASA Astrophysics Data System (ADS)

    Fisher, L. M.; Alferov, D. F.; Akhmetgareev, M. R.; Budovskii, A. I.; Evsin, D. V.; Voloshin, I. F.; Kalinov, A. V.

    2016-12-01

    A resistive switching superconducting fault current limiter (SFCL) for DC networks with a nominal voltage of 3.5 kV and a nominal current of 2 kA was developed, produced, and tested. The SFCL has two main units—an assembly of superconducting modules and a high-speed vacuum circuit breaker. The assembly of superconducting modules consists of nine (3 × 3) parallel-series connected modules. Each module contains four parallel-connected 2G high-temperature superconducting (HTS) tapes. The results of SFCL tests in the short-circuit emulation mode with a maximum current rise rate of 1300 A/ms are presented. The SFCL is capable of limiting the current at a level of 7 kA and break it 8 ms after the current-limiting mode begins. The average temperature of HTS tapes during the current-limiting mode increases to 210 K. After the current is interrupted, the superconductivity recovery time does not exceed 1 s.

  12. Vacuum force

    NASA Astrophysics Data System (ADS)

    Han, Yongquan

    2015-03-01

    To study on vacuum force, we must clear what is vacuum, vacuum is a space do not have any air and also ray. There is not exist an absolute the vacuum of space. The vacuum of space is relative, so that the vacuum force is relative. There is a certain that vacuum vacuum space exists. In fact, the vacuum space is relative, if the two spaces compared to the existence of relative vacuum, there must exist a vacuum force, and the direction of the vacuum force point to the vacuum region. Any object rotates and radiates. Rotate bend radiate- centripetal, gravity produced, relative gravity; non gravity is the vacuum force. Gravity is centripetal, is a trend that the objects who attracted wants to Centripetal, or have been do Centripetal movement. Any object moves, so gravity makes the object curve movement, that is to say, the radiation range curve movement must be in the gravitational objects, gravity must be existed in non vacuum region, and make the object who is in the region of do curve movement (for example: The earth moves around the sun), or final attracted in the form gravitational objects, and keep relatively static with attract object. (for example: objects on the earth moves but can't reach the first cosmic speed).

  13. 46 CFR 58.25-55 - Overcurrent protection for steering-gear systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... overcurrent protection except short-circuit protection that is instantaneous and rated at 400% to 500% of— (1... for steering-gear systems. (a) Each feeder circuit for steering must be protected by a circuit breaker... motor for an alternating-current motor. (b) No feeder circuit for steering may have any overcurrent...

  14. Circuit board accident--organizational dimension hidden by prescribed safety.

    PubMed

    de Almeida, Ildeberto Muniz; Buoso, Eduardo; do Amaral Dias, Maria Dionísia; Vilela, Rodolfo Andrade Gouveia

    2012-01-01

    This study analyzes an accident in which two maintenance workers suffered severe burns while replacing a circuit breaker panel in a steel mill, following model of analysis and prevention of accidents (MAPA) developed with the objective of enlarging the perimeter of interventions and contributing to deconstruction of blame attribution practices. The study was based on materials produced by a health service team in an in-depth analysis of the accident. The analysis shows that decisions related to system modernization were taken without considering their implications in maintenance scheduling and creating conflicts of priorities and of interests between production and safety; and also reveals that the lack of a systemic perspective in safety management was its principal failure. To explain the accident as merely non-fulfillment of idealized formal safety rules feeds practices of blame attribution supported by alibi norms and inhibits possible prevention. In contrast, accident analyses undertaken in worker health surveillance services show potential to reveal origins of these events incubated in the history of the system ignored in practices guided by the traditional paradigm.

  15. Effect of electron irradiation in vacuum on FEP-A silicon solar cell covers

    NASA Technical Reports Server (NTRS)

    Marsik, S. J.; Broder, J. D.

    1975-01-01

    Fluorinated ethylene-propylene-A (FEP-A) covers on silicon solar cells were irradiated with 1-MeV electrons, in vacuum, to an accumulated fluence equivalent to approximately 28 years in synchronous orbit. The effect of irradiation on the light transmittance of FEP-A was checked by measuring the short-circuit current of the cells after each dose increment. The results indicate no apparent overall loss in transmission due to irradiation of FEP-A. Filter wheel measurements revealed some darkening of the FEP-A at the blue end of the spectrum. Although no delamination from the cell surface was observed while in vacuum, embrittlement of FEP-A occurred at the accumulated dose.

  16. Overall behaviour of PFC integrated SST-1 vacuum system

    NASA Astrophysics Data System (ADS)

    Khan, Ziauddin; Raval, Dilip C.; Paravasu, Yuvakiran; Semwal, Pratibha; Dhanani, Kalpeshkumar R.; George, Siju; Shoaib, Mohammad; Prakash, Arun; Babu, Gattu R.; Thankey, Prashant; Pathan, Firozkhan S.; Pradhan, Subrata

    2017-04-01

    As a part of phase-I up-gradation of Steady-state Superconducting Tokamak (SST-1), Graphite Plasma Facing Components (PFCs) have been integrated inside SST-1 vacuum vessel as a first wall (FW) during Nov 14 and May 2015. The SST-1 FW has a total surface area of the installed PFCs exposed to plasma is ∼ 40 m2 which is nearly 50% of the total surface area of stainless steel vacuum chamber (∼75 m2). The volume of the vessel within the PFCs is ∼ 16 m3. After the integration of PFCs, the entire vessel as well as the PFC cooling/baking circuits has been qualified with an integrated helium leak tightness of < 1.0 x 10-8 mbar 1/s. The pumping system of the SST-1 vacuum vessel comprises of one number of Roots’ pump, four numbers of turbomolecular pumps and a cryopump. After the initial pump down, the PFCs were baked at 250 °C for nearly 20 hours employing hot nitrogen gas to remove the absorbed water vapours. Thereafter, Helium glow discharges cleaning were carried out towards the removal of surface impurities. The pump down characteristics of SST-1 vacuum chamber and the changes in the residual gaseous impurities after the installation of the PFCs will be discussed in this paper.

  17. Effect of vacuum arc cathode spot distribution on breaking capacity of the arc-extinguishing chamber

    NASA Astrophysics Data System (ADS)

    Ding, Can; Yuan, Zhao; He, Junjia

    2017-10-01

    A DC circuit breaker performs a key function in breaking an intermediate-frequency (IF) current since breaking a pure IF current is equivalent to breaking a very small DC with a reverse IF current. In this study, it is found that cathode spots show a ring-shaped distribution at 2000 Hz. An arc with an uneven distribution of cathode spots has been simulated. The simulation results show that the distribution of cathode spots significantly affect the microparameter distribution of arc plasma. The current distribution on the anode side differs from that on the cathode side under the total radial electric field. Specifically, the anode current distribution is both uneven and concentrated. The applied axial magnetic field, which cannot reduce the concentrated anode current distribution effectively, might increase the concentration of the anode current. Finally, the uneven distribution of cathode spots reduces the breaking capacity of the arc-extinguishing chamber.

  18. Looking for Trouble

    ERIC Educational Resources Information Center

    Rice, Mike

    2006-01-01

    Circuit breakers are the linchpin of an institution's power-distribution system, so it's not surprising that several warning signs of an aging system relate to these devices. When warning signs occur, it's a message to facilities managers and administrators that breakers may need to be upgraded to help the power distribution system meet existing…

  19. Ethnopharmacological use of babassu (Orbignya phalerata Mart) in communities of babassu nut breakers in Maranhão, Brazil.

    PubMed

    Souza, Mércia H S L; Monteiro, Cristina A; Figueredo, Patricia M S; Nascimento, Flavia Raquel F; Guerra, Rosane N M

    2011-01-07

    Products derived from the palm tree Orbignya phalerata Mart, a species popularly known in Brazil as babassu, are used for the treatment of different diseases such as rheumatism, ulcers and inflammatory processes. The objective of this study was to perform a sociodemographic survey among communities of babassu nut breakers in the region of Médio Mearim, Esperantinópolis, Maranhão, Brazil, and to evaluate the frequency and main forms of therapeutic use of babassu products and subproducts. A semiquantitative method was used for the survey, with the application of semistructured interviews consisting of closed and semi-open questions. The data were analyzed using the SPSS 16.0 software for Windows (2007). The results showed that 82% of female nut breakers had a household income of less than US$ 280.00 and only 2% earned more than US$ 500.00. With respect to race and educational level, 61% of the interviewed women were mulattoes and 33% had a low educational level. The babassu-derived products most frequently used for medicinal purposes were the mesocarp, a residue called "borra", and oil. The mesocarp flour was used by 90% of nut breakers for the treatment of gastritis and inflammation and by 77% for leukorrhea. Babassu residue was mainly used for the treatment of wounds (60%) and the oil was used for woundhealing (16%) and leukorrhea (8%). In conclusion, the products derived from babassu are used for the treatment of gastritis, leukorrhea and wounds. In addition, most of the interviewed subjects apply these products topically. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  20. Electronic zero-point fluctuation forces inside circuit components

    PubMed Central

    Leonhardt, Ulf

    2018-01-01

    One of the most intriguing manifestations of quantum zero-point fluctuations are the van der Waals and Casimir forces, often associated with vacuum fluctuations of the electromagnetic field. We study generalized fluctuation potentials acting on internal degrees of freedom of components in electrical circuits. These electronic Casimir-like potentials are induced by the zero-point current fluctuations of any general conductive circuit. For realistic examples of an electromechanical capacitor and a superconducting qubit, our results reveal the possibility of tunable forces between the capacitor plates, or the level shifts of the qubit, respectively. Our analysis suggests an alternative route toward the exploration of Casimir-like fluctuation potentials, namely, by characterizing and measuring them as a function of parameters of the environment. These tunable potentials may be useful for future nanoelectromechanical and quantum technologies. PMID:29719863

  1. 46 CFR 120.380 - Overcurrent protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... for each ungrounded conductor for the purpose of opening the electric circuit if the current reaches a value that causes an excessive or dangerous temperature in the conductor or conductor insulation. (b) The grounded conductor of a circuit must not be disconnected by a switch or circuit breaker, unless...

  2. 46 CFR 120.380 - Overcurrent protection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... for each ungrounded conductor for the purpose of opening the electric circuit if the current reaches a value that causes an excessive or dangerous temperature in the conductor or conductor insulation. (b) The grounded conductor of a circuit must not be disconnected by a switch or circuit breaker, unless...

  3. Threshold current for fireball generation

    NASA Astrophysics Data System (ADS)

    Dijkhuis, Geert C.

    1982-05-01

    Fireball generation from a high-intensity circuit breaker arc is interpreted here as a quantum-mechanical phenomenon caused by severe cooling of electrode material evaporating from contact surfaces. According to the proposed mechanism, quantum effects appear in the arc plasma when the radius of one magnetic flux quantum inside solid electrode material has shrunk to one London penetration length. A formula derived for the threshold discharge current preceding fireball generation is found compatible with data reported by Silberg. This formula predicts linear scaling of the threshold current with the circuit breaker's electrode radius and concentration of conduction electrons.

  4. Innovation Incubator: Whisker Labs Technical Evaluation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sparn, Bethany F.; Frank, Stephen M.; Earle, Lieko

    The Wells Fargo Innovation Incubator (IN2) is a program to foster and accelerate startup companies with commercial building energy-efficiency and demand management technologies. The program is funded by the Wells Fargo Foundation and co-administered by the National Renewable Energy Laboratory (NREL). Whisker Labs, an Oakland, California-based company, was one of four awardees in the first IN2 cohort and was invited to participate in the program because of its novel electrical power sensing technology for circuit breakers. The stick-on Whisker meters install directly on the front face of the circuit breakers in an electrical panel using adhesive, eliminating the need tomore » open the panel and install current transducers (CTs) on the circuit wiring.« less

  5. 76 FR 10215 - Airworthiness Directives; Learjet Inc. Model 45 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-24

    ... above. This AD requires a general visual inspection for damage of wiring (including chafing, pinched... the pilot and copilot circuit breaker panels caused by a short circuit between chafed wiring and the... misrouted wires, which could result in a short circuit and the loss of systems associated with the wiring...

  6. 14 CFR 25.1701 - Definition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... on electrical devices, including those on relays, interrupters, switches, contactors, terminal blocks and circuit breakers, and other circuit protection devices. (4) Connectors, including feed-through... connections. (7) Electrical splices. (8) Materials used to provide additional protection for wires, including...

  7. 14 CFR 25.1701 - Definition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... on electrical devices, including those on relays, interrupters, switches, contactors, terminal blocks and circuit breakers, and other circuit protection devices. (4) Connectors, including feed-through... connections. (7) Electrical splices. (8) Materials used to provide additional protection for wires, including...

  8. Indian Vacuum Society: The Indian Vacuum Society

    NASA Astrophysics Data System (ADS)

    Saha, T. K.

    2008-03-01

    The Indian Vacuum Society (IVS) was established in 1970. It has over 800 members including many from Industry and R & D Institutions spread throughout India. The society has an active chapter at Kolkata. The society was formed with the main aim to promote, encourage and develop the growth of Vacuum Science, Techniques and Applications in India. In order to achieve this aim it has conducted a number of short term courses at graduate and technician levels on vacuum science and technology on topics ranging from low vacuum to ultrahigh vacuum So far it has conducted 39 such courses at different parts of the country and imparted training to more than 1200 persons in the field. Some of these courses were in-plant training courses conducted on the premises of the establishment and designed to take care of the special needs of the establishment. IVS also regularly conducts national and international seminars and symposia on vacuum science and technology with special emphasis on some theme related to applications of vacuum. A large number of delegates from all over India take part in the deliberations of such seminars and symposia and present their work. IVS also arranges technical visits to different industries and research institutes. The society also helped in the UNESCO sponsored post-graduate level courses in vacuum science, technology and applications conducted by Mumbai University. The society has also designed a certificate and diploma course for graduate level students studying vacuum science and technology and has submitted a syllabus to the academic council of the University of Mumbai for their approval, we hope that some colleges affiliated to the university will start this course from the coming academic year. IVS extended its support in standardizing many of the vacuum instruments and played a vital role in helping to set up a Regional Testing Centre along with BARC. As part of the development of vacuum education, the society arranges the participation of

  9. Design of high-voltage, high-power, solid state remote power controllers for aerospace applications

    NASA Technical Reports Server (NTRS)

    Sturman, J. C.

    1985-01-01

    Two general types of remote power controllers (RPC's), which combine the functions of a circuit breaker and a switch, were developed for use in dc aerospace systems. Power-switching devices used in the designs are the gate-turnoff thyristor (GTO) and MOSFET. The RPC's can switch dc voltages to 1200 V and currents to 1000 A. Seven different units were constructed and subjected to laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times which limit surge currents and voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout proportional to I sq T and microsecond tripout for large overloads.

  10. Design of high-voltage, high-power, solid state remote power controllers for aerospace applications

    NASA Astrophysics Data System (ADS)

    Sturman, J. C.

    1985-05-01

    Two general types of remote power controllers (RPC's), which combine the functions of a circuit breaker and a switch, were developed for use in dc aerospace systems. Power-switching devices used in the designs are the gate-turnoff thyristor (GTO) and MOSFET. The RPC's can switch dc voltages to 1200 V and currents to 1000 A. Seven different units were constructed and subjected to laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times which limit surge currents and voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout proportional to I sq T and microsecond tripout for large overloads.

  11. Synchronous Controlled Switching by VCB with Electromagnetic Operation Mechanism

    NASA Astrophysics Data System (ADS)

    Horinouchi, Katsuhiko; Tsukima, Mitsuru; Tohya, Nobumoto; Inoue, Ryuuichi; Sasao, Hiroyuki

    Synchronously controlled switching to suppress transient overvoltage and overcurrent resulting from when the circuit breakers on medium voltage systems are closed is described. Firstly, by simulation it is found that if the closing time is synchronously controlled so that the contacts of the circuit breaker close completely at the instant when the voltage across contacts of the breaker at each of the three individual phases are zero, the resulting overvoltage and overcurrent is significantly suppressed when compared to conventional three phase simultaneous closing. Next, an algorithm for determining the closing timing based on a forecasted voltage zero waveform, obtained from voltage sampling data, is presented. Finally, a synchronous closing experiment of voltage 22kV utilizing a controller to implement the algorithm and a VCB with an electromagnetic operation mechanism is presented. The VCB was successfully closed at the zero point within a tolerance range of 200 microseconds.

  12. Long life assurance study for manned spacecraft long life hardware. Volume 2: Long life assurance studies of EEE parts and packaging

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Guidelines for the design, development, and fabrication of electronic components and circuits for use in spacecraft construction are presented. The subjects discussed involve quality control procedures and test methodology for the following subjects: (1) monolithic integrated circuits, (2) hybrid integrated circuits, (3) transistors, (4) diodes, (5) tantalum capacitors, (6) electromechanical relays, (7) switches and circuit breakers, and (8) electronic packaging.

  13. Performance characteristics of nanocrystalline diamond vacuum field emission transistor array

    NASA Astrophysics Data System (ADS)

    Hsu, S. H.; Kang, W. P.; Davidson, J. L.; Huang, J. H.; Kerns, D. V.

    2012-06-01

    Nitrogen-incorporated nanocrystalline diamond (ND) vacuum field emission transistor (VFET) with self-aligned gate is fabricated by mold transfer microfabrication technique in conjunction with chemical vapor deposition (CVD) of nanocrystalline diamond on emitter cavity patterned on silicon-on-insulator (SOI) substrate. The fabricated ND-VFET demonstrates gate-controlled emission current with good signal amplification characteristics. The dc characteristics of the ND-VFET show well-defined cutoff, linear, and saturation regions with low gate turn-on voltage, high anode current, negligible gate intercepted current, and large dc voltage gain. The ac performance of the ND-VFET is measured, and the experimental data are analyzed using a modified small signal circuit model. The experimental results obtained for the ac voltage gain are found to agree with the theoretical model. A higher ac voltage gain is attainable by using a better test setup to eliminate the associated parasitic capacitances. The paper reveals the amplifier characteristics of the ND-VFET for potential applications in vacuum microelectronics.

  14. Performance characteristics of nanocrystalline diamond vacuum field emission transistor array

    NASA Astrophysics Data System (ADS)

    Hsu, S. H.; Kang, W. P.; Davidson, J. L.; Huang, J. H.; Kerns, D. V.

    2012-05-01

    Nitrogen-incorporated nanocrystalline diamond (ND) vacuum field emission transistor (VFET) with self-aligned gate is fabricated by mold transfer microfabrication technique in conjunction with chemical vapor deposition (CVD) of nanocrystalline diamond on emitter cavity patterned on silicon-on-insulator (SOI) substrate. The fabricated ND-VFET demonstrates gate-controlled emission current with good signal amplification characteristics. The dc characteristics of the ND-VFET show well-defined cutoff, linear, and saturation regions with low gate turn-on voltage, high anode current, negligible gate intercepted current, and large dc voltage gain. The ac performance of the ND-VFET is measured, and the experimental data are analyzed using a modified small signal circuit model. The experimental results obtained for the ac voltage gain are found to agree with the theoretical model. A higher ac voltage gain is attainable by using a better test setup to eliminate the associated parasitic capacitances. The paper reveals the amplifier characteristics of the ND-VFET for potential applications in vacuum microelectronics.

  15. Vacuum mechatronics

    NASA Technical Reports Server (NTRS)

    Hackwood, Susan; Belinski, Steven E.; Beni, Gerardo

    1989-01-01

    The discipline of vacuum mechatronics is defined as the design and development of vacuum-compatible computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. The importance of vacuum mechatronics is growing with an increased application of vacuum in space studies and in manufacturing for material processing, medicine, microelectronics, emission studies, lyophylisation, freeze drying and packaging. The quickly developing field of vacuum mechatronics will also be the driving force for the realization of an advanced era of totally enclosed clean manufacturing cells. High technology manufacturing has increasingly demanding requirements for precision manipulation, in situ process monitoring and contamination-free environments. To remove the contamination problems associated with human workers, the tendency in many manufacturing processes is to move towards total automation. This will become a requirement in the near future for e.g., microelectronics manufacturing. Automation in ultra-clean manufacturing environments is evolving into the concept of self-contained and fully enclosed manufacturing. A Self Contained Automated Robotic Factory (SCARF) is being developed as a flexible research facility for totally enclosed manufacturing. The construction and successful operation of a SCARF will provide a novel, flexible, self-contained, clean, vacuum manufacturing environment. SCARF also requires very high reliability and intelligent control. The trends in vacuum mechatronics and some of the key research issues are reviewed.

  16. Chelation: A Fundamental Mechanism of Action of AGE Inhibitors, AGE Breakers, and Other Inhibitors of Diabetes Complications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nagai, Rhoji; Murray, David B.; Metz, Thomas O.

    2012-03-01

    Advanced glycation or glycoxidation end-products (AGE) increase in tissue proteins with age, and their rate of accumulation is increased in diabetes, nephropathy and inflammatory diseases. AGE inhibitors include a range of compounds that are proposed to act by trapping carbonyl and dicarbonyl intermediates in AGE formation. However, some among the newer generation of AGE inhibitors lack reactive functional groups that would trap reaction intermediates, indicating an alternative mechanism of action. We propose that AGE inhibitors function primarily as chelators, inhibiting metal-catalyzed oxidation reactions. The AGE-inhibitory activity of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers is also consistent with their chelatingmore » activity. Finally, compounds described as AGE breakers, or their hydrolysis products, also have strong chelating activity, suggesting that these compounds also act through their chelating activity. We conclude that chelation is the common, and perhaps the primary, mechanism of action of AGE inhibitors and breakers, and that chronic, mild chelation therapy should prove useful in treatment of diabetes and age-related diseases characterized by oxidative stress, inflammation and increased chemical modification of tissue proteins by advanced glycoxidation and lipoxidation end-products.« less

  17. System Modeling of a MEMS Vibratory Gyroscope and Integration to Circuit Simulation.

    PubMed

    Kwon, Hyukjin J; Seok, Seyeong; Lim, Geunbae

    2017-11-18

    Recently, consumer applications have dramatically created the demand for low-cost and compact gyroscopes. Therefore, on the basis of microelectromechanical systems (MEMS) technology, many gyroscopes have been developed and successfully commercialized. A MEMS gyroscope consists of a MEMS device and an electrical circuit for self-oscillation and angular-rate detection. Since the MEMS device and circuit are interactively related, the entire system should be analyzed together to design or test the gyroscope. In this study, a MEMS vibratory gyroscope is analyzed based on the system dynamic modeling; thus, it can be mathematically expressed and integrated into a circuit simulator. A behavioral simulation of the entire system was conducted to prove the self-oscillation and angular-rate detection and to determine the circuit parameters to be optimized. From the simulation, the operating characteristic according to the vacuum pressure and scale factor was obtained, which indicated similar trends compared with those of the experimental results. The simulation method presented in this paper can be generalized to a wide range of MEMS devices.

  18. Natural vacuum electronics

    NASA Technical Reports Server (NTRS)

    Leggett, Nickolaus

    1990-01-01

    The ambient natural vacuum of space is proposed as a basis for electron valves. Each valve is an electron controlling structure similiar to a vacuum tube that is operated without a vacuum sustaining envelope. The natural vacuum electron valves discussed offer a viable substitute for solid state devices. The natural vacuum valve is highly resistant to ionizing radiation, system generated electromagnetic pulse, current transients, and direct exposure to space conditions.

  19. Towards programmable plant genetic circuits.

    PubMed

    Medford, June I; Prasad, Ashok

    2016-07-01

    Synthetic biology enables the construction of genetic circuits with predictable gene functions in plants. Detailed quantitative descriptions of the transfer function or input-output function for genetic parts (promoters, 5' and 3' untranslated regions, etc.) are collected. These data are then used in computational simulations to determine their robustness and desired properties, thereby enabling the best components to be selected for experimental testing in plants. In addition, the process forms an iterative workflow which allows vast improvement to validated elements with sub-optimal function. These processes enable computational functions such as digital logic in living plants and follow the pathway of technological advances which took us from vacuum tubes to cell phones. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  20. VACUUM TRAP

    DOEpatents

    Gordon, H.S.

    1959-09-15

    An improved adsorption vacuum trap for use in vacuum systems was designed. The distinguishing feature is the placement of a plurality of torsionally deformed metallic fins within a vacuum jacket extending from the walls to the central axis so that substantially all gas molecules pass through the jacket will impinge upon the fin surfaces. T fins are heated by direct metallic conduction, thereby ol taining a uniform temperature at the adeorbing surfaces so that essentially all of the condensible impurities from the evacuating gas are removed from the vacuum system.

  1. Motor actuated vacuum door. [for photography from sounding rockets

    NASA Technical Reports Server (NTRS)

    Hanagud, A. V.

    1986-01-01

    Doors that allow scientific instruments to record and retrieve the observed data are often required to be designed and installed as a part of sounding rocket hardware. The motor-actuated vacuum door was designed to maintain a medium vacuum of the order of 0.0001 torr or better while closed, and to provide an opening 15 inches long x 8.5 inches wide while open for cameras to image Halley's comet. When the electric motor receives the instruction to open the door through the payload battery, timer, and relay circuit, the first operation is to unlock the door. After unlatching, the torque transmitted by the motor to the main shaft through the links opens the door. A microswitch actuator, which rides on the linear motion conversion mechanism, is adjusted to trip the limit switch at the end of the travel. The process is repeated in the reverse order to close the door. 'O' rings are designed to maintain the seal. Door mechanisms similar to the one described have flown on Aerobee 17.018 and Black Brant 27.047 payloads.

  2. Full circuit calculation for electromagnetic pulse transmission in a high current facility

    NASA Astrophysics Data System (ADS)

    Zou, Wenkang; Guo, Fan; Chen, Lin; Song, Shengyi; Wang, Meng; Xie, Weiping; Deng, Jianjun

    2014-11-01

    We describe herein for the first time a full circuit model for electromagnetic pulse transmission in the Primary Test Stand (PTS)—the first TW class pulsed power driver in China. The PTS is designed to generate 8-10 MA current into a z -pinch load in nearly 90 ns rise time for inertial confinement fusion and other high energy density physics research. The PTS facility has four conical magnetic insulation transmission lines, in which electron current loss exists during the establishment of magnetic insulation. At the same time, equivalent resistance of switches and equivalent inductance of pinch changes with time. However, none of these models are included in a commercially developed circuit code so far. Therefore, in order to characterize the electromagnetic transmission process in the PTS, a full circuit model, in which switch resistance, magnetic insulation transmission line current loss and a time-dependent load can be taken into account, was developed. Circuit topology and an equivalent circuit model of the facility were introduced. Pulse transmission calculation of shot 0057 was demonstrated with the corresponding code FAST (full-circuit analysis and simulation tool) by setting controllable parameters the same as in the experiment. Preliminary full circuit simulation results for electromagnetic pulse transmission to the load are presented. Although divergences exist between calculated and experimentally obtained waveforms before the vacuum section, consistency with load current is satisfactory, especially at the rising edge.

  3. 320 x 240 uncooled IRFPA with pixel wise thin film vacuum packaging

    NASA Astrophysics Data System (ADS)

    Yon, J.-J.; Dumont, G.; Rabaud, W.; Becker, S.; Carle, L.; Goudon, V.; Vialle, C.; Hamelin, A.; Arnaud, A.

    2012-10-01

    Silicon based vacuum packaging is a key enabling technology for achieving affordable uncooled Infrared Focal Plane Arrays (IRFPA) as required by the promising mass market for very low cost IR applications, such as automotive driving assistance, energy loss monitoring in buildings, motion sensors… Among the various approaches studied worldwide, the CEA, LETI is developing a unique technology where each bolometer pixel is sealed under vacuum at the wafer level, using an IR transparent thin film deposition. This technology referred to as PLP (Pixel Level Packaging), leads to an array of hermetic micro-caps each containing a single microbolometer. Since the successful demonstration that the PLP technology, when applied on a single microbolometer pixel, can provide the required vacuum < 10-3 mbar, the authors have pushed forward the development of the technology on fully operational QVGA readout circuits CMOS base wafers (320 x 240 pixels). In this outlook, the article reports on the electro optical performance obtained from this preliminary PLP based QVGA demonstrator. Apart from the response, noise and NETD distributions, the paper also puts emphasis on additional key features such as thermal time constant, image quality, and ageing properties.

  4. 78 FR 5773 - Notification of Proposed Production Activity, Generac Power Systems, Inc., Subzone 41J...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ... assemblies; oil/fuel filters; air/oil separation equipment; air filters/elements; catalytic converters... assemblies; AC line filters; dielectric items of paper/plastic; capacitors; circuit breakers; switching...

  5. Computer Power: Part 1: Distribution of Power (and Communications).

    ERIC Educational Resources Information Center

    Price, Bennett J.

    1988-01-01

    Discussion of the distribution of power to personal computers and computer terminals addresses options such as extension cords, perimeter raceways, and interior raceways. Sidebars explain: (1) the National Electrical Code; (2) volts, amps, and watts; (3) transformers, circuit breakers, and circuits; and (4) power vs. data wiring. (MES)

  6. 29 CFR 1926.403 - General requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... protect other equipment, the adequacy of the protection thus provided. (iii) Electrical insulation. (iv... switchboards, control panels, switches, circuit breakers, motor controllers, relays, and similar equipment...

  7. 30 CFR 28.4 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., assembles, or fabricates, or controls the design, manufacture, assembly, or fabrication of a fuse, and who... means a device, no less effective than an automatic circuit breaker, for use with direct current which... MINING PRODUCTS FUSES FOR USE WITH DIRECT CURRENT IN PROVIDING SHORT-CIRCUIT PROTECTION FOR TRAILING...

  8. 30 CFR 28.4 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., assembles, or fabricates, or controls the design, manufacture, assembly, or fabrication of a fuse, and who... means a device, no less effective than an automatic circuit breaker, for use with direct current which... MINING PRODUCTS FUSES FOR USE WITH DIRECT CURRENT IN PROVIDING SHORT-CIRCUIT PROTECTION FOR TRAILING...

  9. 30 CFR 28.4 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., assembles, or fabricates, or controls the design, manufacture, assembly, or fabrication of a fuse, and who... means a device, no less effective than an automatic circuit breaker, for use with direct current which... MINING PRODUCTS FUSES FOR USE WITH DIRECT CURRENT IN PROVIDING SHORT-CIRCUIT PROTECTION FOR TRAILING...

  10. Comparison of vacuum and non-vacuum urine tubes for urinary sediment analysis.

    PubMed

    Topcuoglu, Canan; Sezer, Sevilay; Kosem, Arzu; Ercan, Mujgan; Turhan, Turan

    2017-12-01

    Urine collection systems with aspiration system for vacuum tubes are becoming increasingly common for urinalysis, especially for microscopic examination of the urine. In this study, we aimed to examine whether vacuum aspiration of the urine sample has any adverse effect on sediment analysis by comparing results from vacuum and non-vacuum urine tubes. The study included totally 213 urine samples obtained from inpatients and outpatients in our hospital. Urine samples were collected to containers with aspiration system for vacuum tubes. Each sample was aliquoted to both vacuum and non-vacuum urine tubes. Urinary sediment analysis was performed using manual microscope. Results were evaluated using chi-square test. Comparison of the sediment analysis results from vacuum and non-vacuum urine tubes showed that results were highly concordant for erythrocyte, leukocyte and epithelial cells (gamma values 1, 0.997, and 0.994, respectively; p < .001). Results were also concordant for urinary casts, crystals and yeast (kappa values 0.815, 0.945 and 1, respectively; p < .001). The results show that in urinary sediment analysis, vacuum aspiration has no adverse effect on the cellular components except on casts.

  11. Study on Power Loss Reduction Considering Load Variation with Large Penetration of Distributed Generation in Smart Grid

    NASA Astrophysics Data System (ADS)

    Liu, Chang; Lv, Xiangyu; Guo, Li; Cai, Lixia; Jie, Jinxing; Su, Kuo

    2017-05-01

    With the increasing of penetration of distributed in the smart grid, the problems that the power loss increasing and short circuit capacity beyond the rated capicity of circuit breaker will become more serious. In this paper, a methodology (Modified BPSO) is presented for network reconfiguration which is based on hybrid approach of Tabu Search and BPSO algorithms to prevent the local convergence and to decrease the calculation time using double fitnesses to consider the constraints. Moreover, an average load simulated method (ALS method) load variation considered is proposed that the average load value is used to instead of the actual load to calculation. Finally, from a case study, the results of simulation certify the approaches will decrease drastically the losses and improve the voltage profiles obviously, at the same time, the short circuit capacity is also decreased into less the shut-off capacity of circuit breaker. The power losses won’t be increased too much even if the short circuit capacity constraint is considered; voltage profiles are better with the constraint of short circuit capacity considering. The ALS method is simple and calculated time is speed.

  12. 33 CFR 183.460 - Overcurrent protection: Special applications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Requirements § 183.460 Overcurrent protection: Special applications. (a) Each ungrounded output conductor from... conductor is in the main power feed circuit from the battery to an engine cranking motor. The circuit breaker or fuse must be within 72 inches of the battery measured along the conductor, unless, for boats...

  13. 33 CFR 183.460 - Overcurrent protection: Special applications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Requirements § 183.460 Overcurrent protection: Special applications. (a) Each ungrounded output conductor from... conductor is in the main power feed circuit from the battery to an engine cranking motor. The circuit breaker or fuse must be within 72 inches of the battery measured along the conductor, unless, for boats...

  14. 46 CFR 169.667 - Switchboards.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Switchboards. 169.667 Section 169.667 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and... circuit must have at the point of attachment to the power source either— (1) A Circuit breaker; or (2) A...

  15. 46 CFR 169.667 - Switchboards.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Switchboards. 169.667 Section 169.667 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and... circuit must have at the point of attachment to the power source either— (1) A Circuit breaker; or (2) A...

  16. 46 CFR 169.667 - Switchboards.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Switchboards. 169.667 Section 169.667 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and... circuit must have at the point of attachment to the power source either— (1) A Circuit breaker; or (2) A...

  17. 46 CFR 169.667 - Switchboards.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Switchboards. 169.667 Section 169.667 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and... circuit must have at the point of attachment to the power source either— (1) A Circuit breaker; or (2) A...

  18. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... The following requirements apply to vehicles with vacuum brake assist units and vacuum brake systems. (a) Vacuum brake assist unit integrity. The vacuum brake assist unit shall demonstrate integrity as... maintained on the pedal. (1) Inspection procedure. Stop the engine and apply service brake several times to...

  19. Electronic circuits and systems: A compilation. [including integrated circuits, logic circuits, varactor diode circuits, low pass filters, and optical equipment circuits

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Technological information is presented electronic circuits and systems which have potential utility outside the aerospace community. Topics discussed include circuit components such as filters, converters, and integrators, circuits designed for use with specific equipment or systems, and circuits designed primarily for use with optical equipment or displays.

  20. Demonstrations with a Vacuum: Old Demonstrations for New Vacuum Pumps.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    1989-01-01

    Explains mechanisms of 19th-century vacuum pumps. Describes demonstrations using the pump including guinea and feather tube, aurora tube, electric egg, Gassiots cascade, air mill, bell in vacuum, density and buoyancy of air, fountain in vacuum, mercury shower, palm and bladder glasses, Bacchus demonstration, pneumatic man-lifter, and Magdeburg…

  1. Hole-transport material variation in fully vacuum deposited perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Polander, Lauren E.; Pahner, Paul; Schwarze, Martin; Saalfrank, Matthias; Koerner, Christian; Leo, Karl

    2014-08-01

    This work addresses the effect of energy level alignment between the hole-transporting material and the active layer in vacuum deposited, planar-heterojunction CH3NH3PbIx-3Clx perovskite solar cells. Through a series of hole-transport materials, with conductivity values set using controlled p-doping of the layer, we correlate their ionization potentials with the open-circuit voltage of the device. With ionization potentials beyond 5.3 eV, a substantial decrease in both current density and voltage is observed, which highlights the delicate energetic balance between driving force for hole-extraction and maximizing the photovoltage. In contrast, when an optimal ionization potential match is found, the open-circuit voltage can be maximized, leading to power conversion efficiencies of up to 10.9%. These values are obtained with hole-transport materials that differ from the commonly used Spiro-MeO-TAD and correspond to a 40% performance increase versus this reference.

  2. The Impact Of Surface Shape Of Chip-Breaker On Machined Surface

    NASA Astrophysics Data System (ADS)

    Šajgalík, Michal; Czán, Andrej; Martinček, Juraj; Varga, Daniel; Hemžský, Pavel; Pitela, David

    2015-12-01

    Machined surface is one of the most used indicators of workpiece quality. But machined surface is influenced by several factors such as cutting parameters, cutting material, shape of cutting tool or cutting insert, micro-structure of machined material and other known as technological parameters. By improving of these parameters, we can improve machined surface. In the machining, there is important to identify the characteristics of main product of these processes - workpiece, but also the byproduct - the chip. Size and shape of chip has impact on lifetime of cutting tools and its inappropriate form can influence the machine functionality and lifetime, too. This article deals with elimination of long chip created when machining of shaft in automotive industry and with impact of shape of chip-breaker on shape of chip in various cutting conditions based on production requirements.

  3. Improved Vacuum Bazooka

    NASA Astrophysics Data System (ADS)

    Cockman, John

    2003-04-01

    This apparatus is a modification to the well-known "vacuum bazooka" (PIRA 2B30.70). My vacuum bazooka is easy to construct and demonstrate, requires no precise fittings, foil, or vacuum grease, and propels ping-pong balls at a tremendous velocity!

  4. Deposition and characterization of ZnS/Si heterojunctions produced by vacuum evaporation

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Loferski, Joseph J.; Beaulieu, Roland

    1988-01-01

    Isotype heterojunctions of ZnS (lattice constant 5.41 A) were grown on silicon (lattice constant 5.43 A) p-n junctions to form a minority-carrier mirror. The deposition process was vacuum evaporation from a ZnS powder source onto a heated (450 C) substrate. Both planar (100) and textured (111) surfaces were used. A reduction of the minority-carrier recombination at the surface was seen from increased short-wavelength quantum response and increased illuminated open-circuit voltage. The minority-carrier diffusion length was not degraded by the process.

  5. 75 FR 61341 - Airworthiness Directives; Agusta S.p.A. (Agusta) Model A109E Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ... electrical failure, an investigation revealed inadequate functioning of the 35 amperes (Amps) battery bus... investigation revealed inadequate functioning of the 35 amperes (Amps) battery bus (BATT BUS) circuit breaker...

  6. 75 FR 38128 - Sensata Technologies MA, Inc., Power Controls Division, Formerly Known As Airpax Corp., Cambridge...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-01

    ... subject firm. The workers are engaged in activities related to the production of hydraulic magnetic... shift in production of hydraulic magnetic circuit breakers to Aguascalientes, Mexico. The amended notice...

  7. 33 CFR 183.455 - Overcurrent protection: General.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....455 Overcurrent protection: General. (a) Each ungrounded current-carrying conductor must be protected... breaker or fuse must be placed at the source of power for each circuit or conductor except: (1) If it is... seven inches of the source of power for each circuit or conductor measured along the conductor. (2) If...

  8. 33 CFR 183.455 - Overcurrent protection: General.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....455 Overcurrent protection: General. (a) Each ungrounded current-carrying conductor must be protected... breaker or fuse must be placed at the source of power for each circuit or conductor except: (1) If it is... seven inches of the source of power for each circuit or conductor measured along the conductor. (2) If...

  9. 75 FR 12793 - Petitions for Modification

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-17

    ... number'' on the subject line, by any of the following methods: 1. Electronic Mail: Standards-Petitions... cables will be no smaller than 10 American Wire Gauge (AWG); (4) all circuit breakers used to protect... unit calibrated to trip at 70% of phase to phase short circuit current. The trip setting of these...

  10. Measurement of eddy-current distribution in the vacuum vessel of the Sino-UNIted Spherical Tokamak.

    PubMed

    Li, G; Tan, Y; Liu, Y Q

    2015-08-01

    Eddy currents have an important effect on tokamak plasma equilibrium and control of magneto hydrodynamic activity. The vacuum vessel of the Sino-UNIted Spherical Tokamak is separated into two hemispherical sections by a toroidal insulating barrier. Consequently, the characteristics of eddy currents are more complex than those found in a standard tokamak. Thus, it is necessary to measure and analyze the eddy-current distribution. In this study, we propose an experimental method for measuring the eddy-current distribution in a vacuum vessel. By placing a flexible printed circuit board with magnetic probes onto the external surface of the vacuum vessel to measure the magnetic field parallel to the surface and then subtracting the magnetic field generated by the vertical-field coils, the magnetic field due to the eddy current can be obtained, and its distribution can be determined. We successfully applied this method to the Sino-UNIted Spherical Tokamak, and thus, we obtained the eddy-current distribution despite the presence of the magnetic field generated by the external coils.

  11. The Classical Vacuum.

    ERIC Educational Resources Information Center

    Boyer, Timothy H.

    1985-01-01

    The classical vacuum of physics is not empty, but contains a distinctive pattern of electromagnetic fields. Discovery of the vacuum, thermal spectrum, classical electron theory, zero-point spectrum, and effects of acceleration are discussed. Connection between thermal radiation and the classical vacuum reveals unexpected unity in the laws of…

  12. Amplifier circuit operable over a wide temperature range

    DOEpatents

    Kelly, Ronald D.; Cannon, William L.

    1979-01-01

    An amplifier circuit having stable performance characteristics over a wide temperature range from approximately 0.degree. C up to as high as approximately 500.degree. C, such as might be encountered in a geothermal borehole. The amplifier utilizes ceramic vacuum tubes connected in directly coupled differential amplifier pairs having a common power supply and a cathode follower output stage. In an alternate embodiment, for operation up to 500.degree. C, positive and negative power supplies are utilized to provide improved gain characteristics, and all electrical connections are made by welding. Resistor elements in this version of the invention are specially heat treated to improve their stability with temperature.

  13. 40 CFR 98.438 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substations, circuit breakers, other switchgear, gas-insulated lines, or power transformers. Fluorinated GHG... transformers containing a fluorinated GHG prior to sale or distribution, or offer for sale or distribution in...

  14. 40 CFR 98.438 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substations, circuit breakers, other switchgear, gas-insulated lines, or power transformers. Fluorinated GHG... transformers containing a fluorinated GHG prior to sale or distribution, or offer for sale or distribution in...

  15. 40 CFR 98.438 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substations, circuit breakers, other switchgear, gas-insulated lines, or power transformers. Fluorinated GHG... transformers containing a fluorinated GHG prior to sale or distribution, or offer for sale or distribution in...

  16. Electroweak vacuum instability and renormalized Higgs field vacuum fluctuations in the inflationary universe

    NASA Astrophysics Data System (ADS)

    Kohri, Kazunori; Matsui, Hiroki

    2017-08-01

    In this work, we investigated the electroweak vacuum instability during or after inflation. In the inflationary Universe, i.e., de Sitter space, the vacuum field fluctuations < δ phi 2 > enlarge in proportion to the Hubble scale H2. Therefore, the large inflationary vacuum fluctuations of the Higgs field < δ phi 2 > are potentially catastrophic to trigger the vacuum transition to the negative-energy Planck-scale vacuum state and cause an immediate collapse of the Universe. However, the vacuum field fluctuations < δ phi 2 >, i.e., the vacuum expectation values have an ultraviolet divergence, and therefore a renormalization is necessary to estimate the physical effects of the vacuum transition. Thus, in this paper, we revisit the electroweak vacuum instability from the perspective of quantum field theory (QFT) in curved space-time, and discuss the dynamical behavior of the homogeneous Higgs field phi determined by the effective potential V eff( phi ) in curved space-time and the renormalized vacuum fluctuations < δ phi 2 >ren via adiabatic regularization and point-splitting regularization. We simply suppose that the Higgs field only couples the gravity via the non-minimal Higgs-gravity coupling ξ(μ). In this scenario, the electroweak vacuum stability is inevitably threatened by the dynamical behavior of the homogeneous Higgs field phi, or the formations of AdS domains or bubbles unless the Hubble scale is small enough H< ΛI .

  17. Architecture, Voltage, and Components for a Turboelectric Distributed Propulsion Electric Grid (AVC-TeDP)

    NASA Technical Reports Server (NTRS)

    Gemin, Paul; Kupiszewski, Tom; Radun, Arthur; Pan, Yan; Lai, Rixin; Zhang, Di; Wang, Ruxi; Wu, Xinhui; Jiang, Yan; Galioto, Steve; hide

    2015-01-01

    The purpose of this effort was to advance the selection, characterization, and modeling of a propulsion electric grid for a Turboelectric Distributed Propulsion (TeDP) system for transport aircraft. The TeDP aircraft would constitute a miniature electric grid with 50 MW or more of total power, two or more generators, redundant transmission lines, and multiple electric motors driving propulsion fans. The study proposed power system architectures, investigated electromechanical and solid state circuit breakers, estimated the impact of the system voltage on system mass, and recommended DC bus voltage range. The study assumed an all cryogenic power system. Detailed assumptions within the study include hybrid circuit breakers, a two cryogen system, and supercritical cyrogens. A dynamic model was developed to investigate control and parameter selection.

  18. Germanium detector vacuum encapsulation

    NASA Technical Reports Server (NTRS)

    Madden, N. W.; Malone, D. F.; Pehl, R. H.; Cork, C. P.; Luke, P. N.; Landis, D. A.; Pollard, M. J.

    1991-01-01

    This paper describes an encapsulation technology that should significantly improve the viability of germanium gamma-ray detectors for a number of important applications. A specialized vacuum chamber has been constructed in which the detector and the encapsulating module are processed in high vacuum. Very high vacuum conductance is achieved within the valveless encapsulating module. The detector module is then sealed without breaking the chamber vacuum. The details of the vacuum chamber, valveless module, processing, and sealing method are presented.

  19. Design and preliminary test results of the 40 MW power supply at the national high magnetic field laboratory

    NASA Astrophysics Data System (ADS)

    Boenig, Heinrich J.; Bogdan, Ferenc; Morris, Gary C.; Ferner, James A.; Schneider-Muntau, Hans J.; Rumrill, Ronald H.; Rumrill, Ronald S.

    1994-07-01

    Four highly stabilized, steady-state, 10 MW power supplies have been installed at the National High Magnetic Field Laboratory in Tallahassee, FL. Each supply consists of a 12.5 kV vacuum circuit breaker, two three-winding, step-down transformers, a 24-pulse rectifier with interphase reactors and freewheeling diodes, and a passive and an active filter. Two different transformer tap settings allow dc supply output voltages of 400 and 500 V. The rated current of a supply is 17 kA and each supply has a one hour overload capability of 20 kA. The power supply output bus system, including a reversing switch at the input and 2 x 16 disconnect switches at the output, connects each supply to 16 different magnet cells. The design of the power supply is described and preliminary test results with a supply feeding a 10 MW resistive load are presented.

  20. Electroweak vacuum instability and renormalized Higgs field vacuum fluctuations in the inflationary universe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kohri, Kazunori; Matsui, Hiroki, E-mail: kohri@post.kek.jp, E-mail: matshiro@post.kek.jp

    In this work, we investigated the electroweak vacuum instability during or after inflation. In the inflationary Universe, i.e., de Sitter space, the vacuum field fluctuations < δ φ {sup 2} > enlarge in proportion to the Hubble scale H {sup 2}. Therefore, the large inflationary vacuum fluctuations of the Higgs field < δ φ {sup 2} > are potentially catastrophic to trigger the vacuum transition to the negative-energy Planck-scale vacuum state and cause an immediate collapse of the Universe. However, the vacuum field fluctuations < δ φ {sup 2} >, i.e., the vacuum expectation values have an ultraviolet divergence, andmore » therefore a renormalization is necessary to estimate the physical effects of the vacuum transition. Thus, in this paper, we revisit the electroweak vacuum instability from the perspective of quantum field theory (QFT) in curved space-time, and discuss the dynamical behavior of the homogeneous Higgs field φ determined by the effective potential V {sub eff}( φ ) in curved space-time and the renormalized vacuum fluctuations < δ φ {sup 2} >{sub ren} via adiabatic regularization and point-splitting regularization. We simply suppose that the Higgs field only couples the gravity via the non-minimal Higgs-gravity coupling ξ(μ). In this scenario, the electroweak vacuum stability is inevitably threatened by the dynamical behavior of the homogeneous Higgs field φ, or the formations of AdS domains or bubbles unless the Hubble scale is small enough H < Λ {sub I} .« less

  1. 77 FR 27144 - Airworthiness Directives; Agusta S.p.A. Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-09

    ... that resulted from ``inadequate functioning of the 35 amperes (amps) BATT BUS circuit breaker.'' The.... (b) Unsafe Condition This AD defines the unsafe condition as failure of the 35 ampere (amp) ``BATT...

  2. Stainless Steel NaK-Cooled Circuit (SNaKC) Fabrication and Assembly

    NASA Technical Reports Server (NTRS)

    Godfroy, Thomas J.

    2007-01-01

    An actively pumped Stainless Steel NaK Circuit (SNaKC) has been designed and fabricated by the Early Flight Fission Test Facility (EFF-TF) team at NASA's Marshall Space Flight Center. This circuit uses the eutectic mixture of sodium and potassium (NaK) as the working fluid building upon the experience and accomplishments of the SNAP reactor program from the late 1960's The SNaKC enables valuable experience and liquid metal test capability to be gained toward the goal of designing and building an affordable surface power reactor. The basic circuit components include a simulated reactor core a NaK to gas heat exchanger, an electromagnetic (EM) liquid metal pump, a liquid metal flow meter, an expansion reservoir and a drain/fill reservoir To maintain an oxygen free environment in the presence of NaK, an argon system is utilized. A helium and nitrogen system are utilized for core, pump, and heat exchanger operation. An additional rest section is available to enable special component testing m an elevated temperature actively pumped liquid metal environment. This paper summarizes the physical build of the SNaKC the gas and pressurization systems, vacuum systems, as well as instrumentation and control methods.

  3. Radiation hard vacuum switch

    DOEpatents

    Boettcher, Gordon E.

    1990-01-01

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction.

  4. Radiation hard vacuum switch

    DOEpatents

    Boettcher, Gordon E.

    1990-03-06

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction.

  5. Demonstration of nonreciprocity in a microwave cavity optomechanical circuit

    NASA Astrophysics Data System (ADS)

    Peterson, Gabriel; Lecocq, Florent; Kotler, Shlomi; Cicak, Katarina; Simmonds, Raymond; Aumentado, Jose; Teufel, John

    The ability to engineer nonreciprocal interactions is essential for many applications including quantum signal processing and quantum transduction. While attributes such as high efficiency and low added noise are always beneficial, for quantum applications these metrics are crucial. Here we present recent experimental results on a parametric, nonreciprocal microwave circuit based on the optomechanical interaction between a superconducting microwave resonator and a mechanically compliant vacuum gap capacitor. Unlike standard Faraday-based circulators, this parametric interaction does not require magnetic fields, and the direction of circulation can be controlled dynamically in situ. Looking forward, such devices could enable programmable, high-efficiency connections between disparate nodes of a quantum network.

  6. 46 CFR 111.30-29 - Emergency switchboards.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... but not in the same space as a battery emergency power source. (d) Each alternating-current emergency... switchboard with a draw out or plug-in type generator circuit breaker that disconnects: (i) Each generator...

  7. 46 CFR 111.30-29 - Emergency switchboards.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... but not in the same space as a battery emergency power source. (d) Each alternating-current emergency... switchboard with a draw out or plug-in type generator circuit breaker that disconnects: (i) Each generator...

  8. 48 CFR 252.212-7001 - Contract terms and conditions required to implement statutes or Executive orders applicable to...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Pub. L. 111-383). (17) __ 252.225-7038, Restriction on Acquisition of Air Circuit Breakers (JUN 2005...-7003, Electronic Submission of Payment Requests and Receiving Reports (MAR 2008) (10 U.S.C. 2227). (23...

  9. Experimental observation of sub-terahertz backward-wave amplification in a multi-level microfabricated slow-wave circuit

    NASA Astrophysics Data System (ADS)

    Baik, Chan-Wook; Ahn, Ho Young; Kim, Yongsung; Lee, Jooho; Hong, Seogwoo; Lee, Sang Hun; Choi, Jun Hee; Kim, Sunil; Jeon, So-Yeon; Yu, SeGi; Collins, George; Read, Michael E.; Lawrence Ives, R.; Kim, Jong Min; Hwang, Sungwoo

    2015-11-01

    In our earlier paper dealing with dispersion retrieval from ultra-deep, reactive-ion-etched, slow-wave circuits on silicon substrates, it was proposed that splitting high-aspect-ratio circuits into multilevels enabled precise characterization in sub-terahertz frequency regime. This achievement prompted us to investigate beam-wave interaction through a vacuum-sealed integration with a 15-kV, 85-mA, thermionic, electron gun. Our experimental study demonstrates sub-terahertz, backward-wave amplification driven by an external oscillator. The measured output shows a frequency downshift, as well as power amplification, from beam loading even with low beam perveance. This offers a promising opportunity for the development of terahertz radiation sources, based on silicon technologies.

  10. Experimental observation of sub-terahertz backward-wave amplification in a multi-level microfabricated slow-wave circuit

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baik, Chan-Wook, E-mail: cw.baik@samsung.com; Ahn, Ho Young; Kim, Yongsung

    2015-11-09

    In our earlier paper dealing with dispersion retrieval from ultra-deep, reactive-ion-etched, slow-wave circuits on silicon substrates, it was proposed that splitting high-aspect-ratio circuits into multilevels enabled precise characterization in sub-terahertz frequency regime. This achievement prompted us to investigate beam-wave interaction through a vacuum-sealed integration with a 15-kV, 85-mA, thermionic, electron gun. Our experimental study demonstrates sub-terahertz, backward-wave amplification driven by an external oscillator. The measured output shows a frequency downshift, as well as power amplification, from beam loading even with low beam perveance. This offers a promising opportunity for the development of terahertz radiation sources, based on silicon technologies.

  11. Vacuum fluctuations in an ancestor vacuum: A possible dark energy candidate

    NASA Astrophysics Data System (ADS)

    Aoki, Hajime; Iso, Satoshi; Lee, Da-Shin; Sekino, Yasuhiro; Yeh, Chen-Pin

    2018-02-01

    We consider an open universe created by bubble nucleation, and study possible effects of our "ancestor vacuum," a de Sitter space in which bubble nucleation occurred, on the present universe. We compute vacuum expectation values of the energy-momentum tensor for a minimally coupled scalar field, carefully taking into account the effect of the ancestor vacuum by the Euclidean prescription. We pay particular attention to the so-called supercurvature mode, a non-normalizable mode on a spatial slice of the open universe, which has been known to exist for sufficiently light fields. This mode decays in time most slowly, and may leave residual effects of the ancestor vacuum, potentially observable in the present universe. We point out that the vacuum energy of the quantum field can be regarded as dark energy if mass of the field is of order the present Hubble parameter or smaller. We obtain preliminary results for the dark energy equation of state w (z ) as a function of the redshift.

  12. 48 CFR 252.212-7001 - Contract terms and conditions required to implement statutes or Executive orders applicable to...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Acquisition of Air Circuit Breakers (JUN 2005) (10 U.S.C. 2534(a)(3)). (18) __ 252.225-7039, Contractors...)). (10 U.S.C. 2321). (23) __ 252.232-7003, Electronic Submission of Payment Requests and Receiving...

  13. ONR Far East Scientific Bulletin. Volume 7. Number 1, January-March 1982.

    DTIC Science & Technology

    1982-03-01

    Engineering - Professor K. Tamaru Associate Professor H. Matsunami - Electronic Circuit Engineering - Professor F. Ikegami Associate Professor S...circuit breakers, ozonizers and production of ozone in silent discharges, and superconducting equipment. In addition, a very brief report is given of a...treatment plants (Mitsubishi Electric ozonizer work is discussed later in this paper), - electric fans including ventilating systems for long highway

  14. Electricity Submetering on the Cheap: Stick-on Electricity Meters

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lanzisera, Steven; Lorek, Michael; Pister, Kristofer

    2014-08-17

    We demonstrate a low-cost, 21 x 12 mm prototype Stick-on Electricity Meter (SEM) to replace traditional in-circuit-breaker-panel current and voltage sensors for building submetering. A SEM sensor is installed on the external face of a circuit breaker to generate voltage and current signals. This allows for the computation of real and apparent power as well as capturing harmonics created by non-linear loads. The prototype sensor is built using commercially available components, resulting in a production cost of under $10 per SEM. With no highvoltage install work requiring an electrician, home owners or other individuals can install the system in amore » few minutes with no safety implications. This leads to an installed system cost that is much lower than traditional submetering technology.. Measurement results from lab characterization as well as a real-world residential dwelling installation are presented, verifying the operation of our proposed SEM sensor. The SEM sensor can resolve breaker power levels below 10W, and it can be used to provide data for non-intrusive load monitoring systems at full sample rate.« less

  15. Measuring circuit

    DOEpatents

    Sun, Shan C.; Chaprnka, Anthony G.

    1977-01-11

    An automatic gain control circuit functions to adjust the magnitude of an input signal supplied to a measuring circuit to a level within the dynamic range of the measuring circuit while a log-ratio circuit adjusts the magnitude of the output signal from the measuring circuit to the level of the input signal and optimizes the signal-to-noise ratio performance of the measuring circuit.

  16. Vacuum Virtues

    ERIC Educational Resources Information Center

    Rathey, Allen

    2007-01-01

    Upright vacuums, like cars, vary in quality, features and performance. Like automobiles, some uprights are reliable, others may be problematic, and some become a problem as a result of neglect or improper use. So, how do education institutions make an informed choice and, having done so, ensure that an upright vacuum goes the distance? In this…

  17. Coaxial twin-shaft magnetic fluid seals applied in vacuum wafer-handling robot

    NASA Astrophysics Data System (ADS)

    Cong, Ming; Wen, Haiying; Du, Yu; Dai, Penglei

    2012-07-01

    Compared with traditional mechanical seals, magnetic fluid seals have unique characters of high airtightness, minimal friction torque requirements, pollution-free and long life-span, widely used in vacuum robots. With the rapid development of Integrate Circuit (IC), there is a stringent requirement for sealing wafer-handling robots when working in a vacuum environment. The parameters of magnetic fluid seals structure is very important in the vacuum robot design. This paper gives a magnetic fluid seal device for the robot. Firstly, the seal differential pressure formulas of magnetic fluid seal are deduced according to the theory of ferrohydrodynamics, which indicate that the magnetic field gradient in the sealing gap determines the seal capacity of magnetic fluid seal. Secondly, the magnetic analysis model of twin-shaft magnetic fluid seals structure is established. By analyzing the magnetic field distribution of dual magnetic fluid seal, the optimal value ranges of important parameters, including parameters of the permanent magnetic ring, the magnetic pole tooth, the outer shaft, the outer shaft sleeve and the axial relative position of two permanent magnetic rings, which affect the seal differential pressure, are obtained. A wafer-handling robot equipped with coaxial twin-shaft magnetic fluid rotary seals and bellows seal is devised and an optimized twin-shaft magnetic fluid seals experimental platform is built. Test result shows that when the speed of the two rotational shafts ranges from 0-500 r/min, the maximum burst pressure is about 0.24 MPa. Magnetic fluid rotary seals can provide satisfactory performance in the application of wafer-handling robot. The proposed coaxial twin-shaft magnetic fluid rotary seal provides the instruction to design high-speed vacuum robot.

  18. Microfluidic Pneumatic Logic Circuits and Digital Pneumatic Microprocessors for Integrated Microfluidic Systems

    PubMed Central

    Rhee, Minsoung

    2010-01-01

    We have developed pneumatic logic circuits and microprocessors built with microfluidic channels and valves in polydimethylsiloxane (PDMS). The pneumatic logic circuits perform various combinational and sequential logic calculations with binary pneumatic signals (atmosphere and vacuum), producing cascadable outputs based on Boolean operations. A complex microprocessor is constructed from combinations of various logic circuits and receives pneumatically encoded serial commands at a single input line. The device then decodes the temporal command sequence by spatial parallelization, computes necessary logic calculations between parallelized command bits, stores command information for signal transportation and maintenance, and finally executes the command for the target devices. Thus, such pneumatic microprocessors will function as a universal on-chip control platform to perform complex parallel operations for large-scale integrated microfluidic devices. To demonstrate the working principles, we have built 2-bit, 3-bit, 4-bit, and 8-bit microprecessors to control various target devices for applications such as four color dye mixing, and multiplexed channel fluidic control. By significantly reducing the need for external controllers, the digital pneumatic microprocessor can be used as a universal on-chip platform to autonomously manipulate microfluids in a high throughput manner. PMID:19823730

  19. Microfabricated triggered vacuum switch

    DOEpatents

    Roesler, Alexander W [Tijeras, NM; Schare, Joshua M [Albuquerque, NM; Bunch, Kyle [Albuquerque, NM

    2010-05-11

    A microfabricated vacuum switch is disclosed which includes a substrate upon which an anode, cathode and trigger electrode are located. A cover is sealed over the substrate under vacuum to complete the vacuum switch. In some embodiments of the present invention, a metal cover can be used in place of the trigger electrode on the substrate. Materials used for the vacuum switch are compatible with high vacuum, relatively high temperature processing. These materials include molybdenum, niobium, copper, tungsten, aluminum and alloys thereof for the anode and cathode. Carbon in the form of graphitic carbon, a diamond-like material, or carbon nanotubes can be used in the trigger electrode. Channels can be optionally formed in the substrate to mitigate against surface breakdown.

  20. The ice-breaker effect: singing mediates fast social bonding.

    PubMed

    Pearce, Eiluned; Launay, Jacques; Dunbar, Robin I M

    2015-10-01

    It has been proposed that singing evolved to facilitate social cohesion. However, it remains unclear whether bonding arises out of properties intrinsic to singing or whether any social engagement can have a similar effect. Furthermore, previous research has used one-off singing sessions without exploring the emergence of social bonding over time. In this semi-naturalistic study, we followed newly formed singing and non-singing (crafts or creative writing) adult education classes over seven months. Participants rated their closeness to their group and their affect, and were given a proxy measure of endorphin release, before and after their class, at three timepoints (months 1, 3 and 7). We show that although singers and non-singers felt equally connected by timepoint 3, singers experienced much faster bonding: singers demonstrated a significantly greater increase in closeness at timepoint 1, but the more gradual increase shown by non-singers caught up over time. This represents the first evidence for an 'ice-breaker effect' of singing in promoting fast cohesion between unfamiliar individuals, which bypasses the need for personal knowledge of group members gained through prolonged interaction. We argue that singing may have evolved to quickly bond large human groups of relative strangers, potentially through encouraging willingness to coordinate by enhancing positive affect.

  1. The ice-breaker effect: singing mediates fast social bonding

    PubMed Central

    Pearce, Eiluned; Launay, Jacques; Dunbar, Robin I. M.

    2015-01-01

    It has been proposed that singing evolved to facilitate social cohesion. However, it remains unclear whether bonding arises out of properties intrinsic to singing or whether any social engagement can have a similar effect. Furthermore, previous research has used one-off singing sessions without exploring the emergence of social bonding over time. In this semi-naturalistic study, we followed newly formed singing and non-singing (crafts or creative writing) adult education classes over seven months. Participants rated their closeness to their group and their affect, and were given a proxy measure of endorphin release, before and after their class, at three timepoints (months 1, 3 and 7). We show that although singers and non-singers felt equally connected by timepoint 3, singers experienced much faster bonding: singers demonstrated a significantly greater increase in closeness at timepoint 1, but the more gradual increase shown by non-singers caught up over time. This represents the first evidence for an ‘ice-breaker effect’ of singing in promoting fast cohesion between unfamiliar individuals, which bypasses the need for personal knowledge of group members gained through prolonged interaction. We argue that singing may have evolved to quickly bond large human groups of relative strangers, potentially through encouraging willingness to coordinate by enhancing positive affect. PMID:26587241

  2. Project Circuits in a Basic Electric Circuits Course

    ERIC Educational Resources Information Center

    Becker, James P.; Plumb, Carolyn; Revia, Richard A.

    2014-01-01

    The use of project circuits (a photoplethysmograph circuit and a simple audio amplifier), introduced in a sophomore-level electric circuits course utilizing active learning and inquiry-based methods, is described. The development of the project circuits was initiated to promote enhanced engagement and deeper understanding of course content among…

  3. 48 CFR 252.212-7001 - Contract terms and conditions required to implement statutes or Executive orders applicable to...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....225-7036. (15) __252.225-7038, Restriction on Acquisition of Air Circuit Breakers (JUN 2005) (10 U.S.C... Data (SEP 1999) (10 U.S.C. 2321). (19) __252.232-7003, Electronic Submission of Payment Requests and...

  4. Electronic circuits

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Twenty-nine circuits and circuit techniques developed for communications and instrumentation technology are described. Topics include pulse-code modulation, phase-locked loops, data coding, data recording, detection circuits, logic circuits, oscillators, and amplifiers.

  5. In vitro and in vivo evaluation of Dideco's paediatric cardiopulmonary circuit for neonates weighing less than five kilograms.

    PubMed

    Thiara, A S; Eggereide, V; Pedersen, T; Lindberg, H; Fiane, A E

    2010-07-01

    The neonate cardiopulmonary bypass (CPB) circuit, including a KIDS D100 oxygenator (The Sorin Group, Mirandola, Italy) and a D130 arterial filter (The Sorin Group), was evaluated in vitro with respect to the removal of free micro gas bubbles. No gas bubbles > 40microm were measured after the arterial filter D130 upon manual introduction of 10 ml of air into the venous line or during the use of vacuum-assisted venous drainage (VAVD). The D130 arterial filter removed 88 % of gas bubbles < 40 microm during manual introduction of air into the venous line; however, only 50 % of gas bubbles < 40 microm were removed during the use of VAVD. The same CPB circuit was evaluated in vivo to compare with another CPB circuit, including a D901 oxygenator (The Sorin Group) and arterial filter D736 (The Sorin Group), in 155 neonates weighing < or =5 kg. The D100 circuit required significantly less priming volume than the D901 circuit. Postoperative haemoglobin was significantly higher, artificial ventilation time was significantly shorter and postoperative bleeding was significantly less in the D100 group. This neonate CPB circuit effectively removed the gas bubbles and required up to 37% less priming volume and, thus, decreased the need for blood transfusion.

  6. Synaptic organic transistors with a vacuum-deposited charge-trapping nanosheet

    PubMed Central

    Kim, Chang-Hyun; Sung, Sujin; Yoon, Myung-Han

    2016-01-01

    Organic neuromorphic devices hold great promise for unconventional signal processing and efficient human-machine interfaces. Herein, we propose novel synaptic organic transistors devised to overcome the traditional trade-off between channel conductance and memory performance. A vacuum-processed, nanoscale metallic interlayer provides an ultra-flat surface for a high-mobility molecular film as well as a desirable degree of charge trapping, allowing for low-temperature fabrication of uniform device arrays on plastic. The device architecture is implemented by widely available electronic materials in combination with conventional deposition methods. Therefore, our results are expected to generate broader interests in incorporation of organic electronics into large-area neuromorphic systems, with potential in gate-addressable complex logic circuits and transparent multifunctional interfaces receiving direct optical and cellular stimulation. PMID:27645425

  7. Synaptic organic transistors with a vacuum-deposited charge-trapping nanosheet

    NASA Astrophysics Data System (ADS)

    Kim, Chang-Hyun; Sung, Sujin; Yoon, Myung-Han

    2016-09-01

    Organic neuromorphic devices hold great promise for unconventional signal processing and efficient human-machine interfaces. Herein, we propose novel synaptic organic transistors devised to overcome the traditional trade-off between channel conductance and memory performance. A vacuum-processed, nanoscale metallic interlayer provides an ultra-flat surface for a high-mobility molecular film as well as a desirable degree of charge trapping, allowing for low-temperature fabrication of uniform device arrays on plastic. The device architecture is implemented by widely available electronic materials in combination with conventional deposition methods. Therefore, our results are expected to generate broader interests in incorporation of organic electronics into large-area neuromorphic systems, with potential in gate-addressable complex logic circuits and transparent multifunctional interfaces receiving direct optical and cellular stimulation.

  8. General and crevice corrosion study of the in-wall shielding materials for ITER vacuum vessel

    NASA Astrophysics Data System (ADS)

    Joshi, K. S.; Pathak, H. A.; Dayal, R. K.; Bafna, V. K.; Kimihiro, Ioki; Barabash, V.

    2012-11-01

    Vacuum vessel In-Wall Shield (IWS) will be inserted between the inner and outer shells of the ITER vacuum vessel. The behaviour of IWS in the vacuum vessel especially concerning the susceptibility to crevice of shielding block assemblies could cause rapid and extensive corrosion attacks. Even galvanic corrosion may be due to different metals in same electrolyte. IWS blocks are not accessible until life of the machine after closing of vacuum vessel. Hence, it is necessary to study the susceptibility of IWS materials to general corrosion and crevice corrosion under operations of ITER vacuum vessel. Corrosion properties of IWS materials were studied by using (i) Immersion technique and (ii) Electro-chemical Polarization techniques. All the sample materials were subjected to a series of examinations before and after immersion test, like Loss/Gain weight measurement, SEM analysis, and Optical stereo microscopy, measurement of surface profile and hardness of materials. After immersion test, SS 304B4 and SS 304B7 showed slight weight gain which indicate oxide layer formation on the surface of coupons. The SS 430 material showed negligible weight loss which indicates mild general corrosion effect. On visual observation with SEM and Metallography, all material showed pitting corrosion attack. All sample materials were subjected to series of measurements like Open Circuit potential, Cyclic polarization, Pitting potential, protection potential, Critical anodic current and SEM examination. All materials show pitting loop in OC2 operating condition. However, its absence in OC1 operating condition clearly indicates the activity of chloride ion to penetrate oxide layer on the sample surface, at higher temperature. The critical pitting temperature of all samples remains between 100° and 200°C.

  9. Vacuum probe surface sampler

    NASA Technical Reports Server (NTRS)

    Zahlava, B. A. (Inventor)

    1973-01-01

    A vacuum probe surface sampler is described for rapidly sampling relatively large surface areas which possess relatively light loading densities of micro-organism, drug particles or the like. A vacuum head with a hollow handle connected to a suitable vacuum source is frictionally attached to a cone assembly terminating in a flared tip adapted to be passed over the surface to be sampled. A fine mesh screen carried by the vacuum head provides support for a membrane filter which collects the microorganisms or other particles. The head assembly is easily removed from the cone assembly without contacting the cone assembly with human hands.

  10. Comparison of work rates, energy expenditure, and perceived exertion during a 1-h vacuuming task with a backpack vacuum cleaner and an upright vacuum cleaner.

    PubMed

    Mengelkoch, Larry J; Clark, Kirby

    2006-03-01

    The purpose of this study was to evaluate two types of industrial vacuum cleaners, in terms of cleaning rates, energy expenditure, and perceived exertion. Twelve industrial cleaners (six males and six females, age 28-39 yr) performed two 1-h vacuuming tasks with an upright vacuum cleaner (UVC) and a backpack vacuum cleaner (BPVC). Measures for oxygen uptake (VO2) and ratings of perceived exertion (RPE) were collected continuously during the 1-h vacuuming tasks. Cleaning rates for the UVC and BPVC were 7.23 and 14.98 m2min(-1), respectively. On a separate day subjects performed a maximal treadmill exercise test to determine their maximal aerobic capacity (peak VO2). Average absolute energy costs (in Metabolic equivalents), relative energy costs of the vacuum task compared to the subjects' maximal aerobic capacity (% peak VO2), and RPE responses for the 1-h vacuuming tasks were similar between vacuum cleaners, but % peak VO2 and RPE values differed between genders. These results indicate that the BPVC was more efficient than the UVC. With the BPVC, experienced workers vacuumed at a cleaning rate 2.07 times greater than the UVC and had similar levels of energy expenditure and perceived effort, compared to the slower cleaning rate with the UVC.

  11. Use of Fuzzy Logic Systems for Assessment of Primary Faults

    NASA Astrophysics Data System (ADS)

    Petrović, Ivica; Jozsa, Lajos; Baus, Zoran

    2015-09-01

    In electric power systems, grid elements are often subjected to very complex and demanding disturbances or dangerous operating conditions. Determining initial fault or cause of those states is a difficult task. When fault occurs, often it is an imperative to disconnect affected grid element from the grid. This paper contains an overview of possibilities for using fuzzy logic in an assessment of primary faults in the transmission grid. The tool for this task is SCADA system, which is based on information of currents, voltages, events of protection devices and status of circuit breakers in the grid. The function model described with the membership function and fuzzy logic systems will be presented in the paper. For input data, diagnostics system uses information of protection devices tripping, states of circuit breakers and measurements of currents and voltages before and after faults.

  12. Thomson scattering diagnostics of decay processes of Ar/SF6 gas-blast arcs confined by a nozzle

    NASA Astrophysics Data System (ADS)

    Tomita, Kentaro; Gojima, Daisuke; Nagai, Kazuhiko; Uchino, Kiichiro; Kamimae, Ryo; Tanaka, Yasunori; Suzuki, Katsumi; Iijima, Takanori; Uchii, Toshiyuki; Shinkai, Takeshi

    2013-09-01

    Because of its instability, it is difficult to measure precisely the electron density (ne) of a long-gap decaying arc discharge in a circuit breaker. However, it is well known that it is an essential parameter for the determination of success or failure of the current interruption in a circuit breaker. In this paper, the spatiotemporal evolutions of the electron density were successfully measured in decaying SF6 gas-blast arc discharges formed with a long gap (50 mm) in a confined nozzle using laser Thomson scattering. Pure Ar gas and an 80%Ar/20%SF6 mixture gas were used as the arc quenching media at atmospheric pressure. After reducing the current to zero, both the measured ne and arc radius in the Ar/SF6 gas arc clearly decayed more rapidly than in the pure Ar gas arc.

  13. Relation between plastic surface microtexturation and Ag film percolation and resistivity

    NASA Astrophysics Data System (ADS)

    Rapeaux, Michel; Tribut, Laurent

    2017-09-01

    Reinforced polycarbonate samples are textured by laser to get hydrophilic or hydrophobic surface. Then, Ag films are deposited on textured and non-textured samples by magnetron sputtering. In-situ resistivity measurement has been done to determine the electrical percolation threshold according to the texturation. Results are discussed and texturation is presented as one option to improve surface insulation in circuit breaker after a short-circuit event.

  14. 40 CFR 63.441 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... flash steam from the digester or live steam. Closed-vent system means a system that is not open to the... this subpart, including emissions from individual process vents, stacks, open pieces of process... stock chests, and their associated vacuum pumps, filtrate tanks, foam breakers or tanks, and any other...

  15. 40 CFR 63.441 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... flash steam from the digester or live steam. Closed-vent system means a system that is not open to the... this subpart, including emissions from individual process vents, stacks, open pieces of process... stock chests, and their associated vacuum pumps, filtrate tanks, foam breakers or tanks, and any other...

  16. 40 CFR 63.441 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... flash steam from the digester or live steam. Closed-vent system means a system that is not open to the... this subpart, including emissions from individual process vents, stacks, open pieces of process... stock chests, and their associated vacuum pumps, filtrate tanks, foam breakers or tanks, and any other...

  17. 40 CFR 63.441 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... or live steam. Closed-vent system means a system that is not open to the atmosphere and is composed... emissions from individual process vents, stacks, open pieces of process equipment, equipment leaks... stock chests, and their associated vacuum pumps, filtrate tanks, foam breakers or tanks, and any other...

  18. 40 CFR 63.441 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... or live steam. Closed-vent system means a system that is not open to the atmosphere and is composed... emissions from individual process vents, stacks, open pieces of process equipment, equipment leaks... stock chests, and their associated vacuum pumps, filtrate tanks, foam breakers or tanks, and any other...

  19. A radiation hard vacuum switch

    DOEpatents

    Boettcher, G.E.

    1988-07-19

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction. 3 figs.

  20. Comparison of vacuum rise time, vacuum limit accuracy, and occlusion break surge of 3 new phacoemulsification systems.

    PubMed

    Han, Young Keun; Miller, Kevin M

    2009-08-01

    To compare vacuum rise time, vacuum limit accuracy, and occlusion break surge of 3 new phacoemulsification machines. Jules Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA. The vacuum rise time under normal and enhanced aspiration modes, vacuum limit accuracy, and occlusion break surge of the Infiniti Vision System, Stellaris Vision Enhancement System, and WhiteStar Signature Phacoemulsification System were tested. Vacuum rise time and limit accuracy were measured at limit settings of 400 mm Hg and 600 mm Hg. Surge area was recorded at vacuum limit settings of 200 mm Hg, 300 mm Hg, 400 mm Hg, and 500 mm Hg. The Infiniti had the fastest vacuum rise times under normal and enhanced aspiration modes. At 4 seconds, the vacuum limit accuracy was greatest with the Infiniti at the 400 mm Hg limit and the Signature at the 600 mm Hg limit. The Stellaris did not reach either vacuum target. The Infiniti performed better than the other 2 machines during testing of occlusion break surge at all vacuum limit settings above 200 mm Hg. Under controlled laboratory test conditions, the Infiniti had the fastest vacuum rise time, greatest vacuum limit accuracy at 400 mm Hg, and least occlusion break surge. These results can be explained by the lower compliance of the Infiniti system.

  1. Compensated gain control circuit for buck regulator command charge circuit

    DOEpatents

    Barrett, David M.

    1996-01-01

    A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit.

  2. Air bearing vacuum seal assembly

    DOEpatents

    Booth, Rex

    1978-01-01

    An air bearing vacuum seal assembly capable of rotating at the speed of several thousand revolutions per minute using an air cushion to prevent the rotating and stationary parts from touching, and a two stage differential pumping arrangement to maintain the pressure gradient between the air cushion and the vacuum so that the leak rate into the vacuum is, for example, less than 1 .times. 10.sup.-4 Pa m.sup.3 /s. The air bearing vacuum seal has particular application for mounting rotating targets to an evacuated accelerator beam tube for bombardment of the targets with high-power charged particle beams in vacuum.

  3. The Combat-System/Ship-System Interface,

    DTIC Science & Technology

    1982-02-01

    sequence initiated by removal of the load shed signal. Re-eneAgize capabitiLty. Provide remotely controlled reclosable power control devices to...signal from the electrical plant control equipment. The power controllers would replace existing circuit breakers and incorporate reclose capability

  4. Compensated gain control circuit for buck regulator command charge circuit

    DOEpatents

    Barrett, D.M.

    1996-11-05

    A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit. 5 figs.

  5. Vacuum-Gauge Connection For Shipping Container

    NASA Technical Reports Server (NTRS)

    Henry, Robert H.

    1990-01-01

    External connector enables measurement of vacuum in stored part. Remote-readout connector added to shipping container and connected to thermo-couple vacuum gauge in vacuum-insulated cryogenic line packed in container. Enables monitoring of condition of vacuum without opening container.

  6. Addressing Circuitous Currents MVDC Power Systems Protection

    DTIC Science & Technology

    2017-12-31

    load . The converter modules are current-controlled buck converters. They are being controlled to provide a no - load voltage of 155V at their outputs...PAGE Form Approved 0MB No . 0704-0188 The public reporting burden for this collection of information is estimated to average 1 hour per response...distribution is unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The work investigates Z-source breakers in multi-zone systems with current to the load through

  7. NSLS II Vacuum System

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ferreira, M.; Doom, L.; Hseuh, H.

    2009-09-13

    National Synchrotron Light Source II, being constructed at Brookhaven, is a 3-GeV, 500 mA, 3rd generation synchrotron radiation facility with ultra low emittance electron beams. The storage ring vacuum system has a circumference of 792 m and consists of over 250 vacuum chambers with a simulated average operating pressure of less than 1 x 10{sup -9} mbar. A summary of the update design of the vacuum system including girder supports of the chambers, gauges, vacuum pumps, bellows, beam position monitors and simulation of the average pressure will be shown. A brief description of the techniques and procedures for cleaning andmore » mounting the chambers are given.« less

  8. Effective Porosity Measurements by Wet- and Dry-type Vacuum Saturations using Process-Programmable Vacuum Saturation System

    NASA Astrophysics Data System (ADS)

    Lee, T. J.; Lee, K. S., , Dr; Lee, S. K.

    2017-12-01

    One of the most important factors in measuring effective porosity by vacuum saturation method is that the air in the pore space can be fully substituted by water during the vacuum saturation process. International Society of Rock Mechanics (ISRM) suggests vacuuming a rock sample submerged in the water, while American Society of Test and Materials (ASTM) vacuuming the sample and water separately and then pour the water to the sample. In this study, we call the former wet-type vacuum saturation (WVS) method and the latter dry-type vacuum saturation (DVS) method, and compare the effective porosity measured by the two different vacuum saturation processes. For that purpose, a vacuum saturation system has been developed, which can support both WVS and DVS by only changing the process by programming. Comparison of effective porosity has been made for a cement mortar and rock samples. As a result, DVS can substitute more void volume to water than WVS, which in turn insists that DVS can provide more exact value of effective porosity than WVS.

  9. Smooth criminal: convicted rule-breakers show reduced cognitive conflict during deliberate rule violations.

    PubMed

    Jusyte, Aiste; Pfister, Roland; Mayer, Sarah V; Schwarz, Katharina A; Wirth, Robert; Kunde, Wilfried; Schönenberg, Michael

    2017-09-01

    Classic findings on conformity and obedience document a strong and automatic drive of human agents to follow any type of rule or social norm. At the same time, most individuals tend to violate rules on occasion, and such deliberate rule violations have recently been shown to yield cognitive conflict for the rule-breaker. These findings indicate persistent difficulty to suppress the rule representation, even though rule violations were studied in a controlled experimental setting with neither gains nor possible sanctions for violators. In the current study, we validate these findings by showing that convicted criminals, i.e., individuals with a history of habitual and severe forms of rule violations, can free themselves from such cognitive conflict in a similarly controlled laboratory task. These findings support an emerging view that aims at understanding rule violations from the perspective of the violating agent rather than from the perspective of outside observer.

  10. Influence of deep cryogenic treatment on structure and wear resistance of materials of hydraulic breaker chisels

    NASA Astrophysics Data System (ADS)

    Bolobov, V. I.; BinhLe, Thanh

    2018-03-01

    It is shown that shallow cryogenic treatment at -75°C (SCT) of the materials of hydraulic breaker chisels - P20, 1080 and D2 steels leads to a decrease (44 ÷ 82%) in the amount of retained austenite and an increase (26 ÷ 99%) in the amount of carbides in the structure of hardened steel, which is accompanied by an increase in its hardness (1.4 ÷ 2.1%) and abrasive wear resistance (10 ÷ 31%) with a simultaneous decrease in impact toughness (19 ÷ 24%). Deep cryogenic treatment at -196°C (DCT) and subsequent low-temperature tempering of D2 steel leads to a significant increase in its wear resistance (98%) and impact toughness (32%).

  11. Theoretical analysis of cross-talking signals between counter-streaming electron beams in a vacuum tube oscillator

    NASA Astrophysics Data System (ADS)

    Shin, Y. M.; Ryskin, N. M.; Won, J. H.; Han, S. T.; Park, G. S.

    2006-03-01

    The basic theory of cross-talking signals between counter-streaming electron beams in a vacuum tube oscillator consisting of two two-cavity klystron amplifiers reversely coupled through input/output slots is theoretically investigated. Application of Kirchhoff's laws to the coupled equivalent RLC circuit model of the device provides four nonlinear coupled equations, which are the first-order time-delayed differential equations. Analytical solutions obtained through linearization of the equations provide oscillation frequencies and thresholds of four fundamental eigenstates, symmetric/antisymmetric 0/π modes. Time-dependent output signals are numerically analyzed with variation of the beam current, and a self-modulation mechanism and transition to chaos scenario are examined. The oscillator shows a much stronger multistability compared to a delayed feedback klystron oscillator owing to the competitions among more diverse eigenmodes. A fully developed chaos region also appears at a relatively lower beam current, ˜3.5Ist, compared to typical vacuum tube oscillators (10-100Ist), where Ist is a start-oscillation current.

  12. Circuit model of the ITER-like antenna for JET and simulation of its control algorithms

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Durodié, Frédéric, E-mail: frederic.durodie@rma.ac.be; Křivská, Alena; Dumortier, Pierre

    2015-12-10

    The ITER-like Antenna (ILA) for JET [1] is a 2 toroidal by 2 poloidal array of Resonant Double Loops (RDL) featuring in-vessel matching capacitors feeding RF current straps in conjugate-T manner, a low impedance quarter-wave impedance transformer, a service stub allowing hydraulic actuator and water cooling services to reach the aforementioned capacitors and a 2nd stage phase-shifter-stub matching circuit allowing to correct/choose the conjugate-T working impedance. Toroidally adjacent RDLs are fed from a 3dB hybrid splitter. It has been operated at 33, 42 and 47MHz on plasma (2008-2009) while it presently estimated frequency range is from 29 to 49MHz. Atmore » the time of the design (2001-2004) as well as the experiments the circuit models of the ILA were quite basic. The ILA front face and strap array Topica model was relatively crude and failed to correctly represent the poloidal central septum, Faraday Screen attachment as well as the segmented antenna central septum limiter. The ILA matching capacitors, T-junction, Vacuum Transmission Line (VTL) and Service Stubs were represented by lumped circuit elements and simple transmission line models. The assessment of the ILA results carried out to decide on the repair of the ILA identified that achieving routine full array operation requires a better understanding of the RF circuit, a feedback control algorithm for the 2nd stage matching as well as tighter calibrations of RF measurements. The paper presents the progress in modelling of the ILA comprising a more detailed Topica model of the front face for various plasma Scrape Off Layer profiles, a comprehensive HFSS model of the matching capacitors including internal bellows and electrode cylinders, 3D-EM models of the VTL including vacuum ceramic window, Service stub, a transmission line model of the 2nd stage matching circuit and main transmission lines including the 3dB hybrid splitters. A time evolving simulation using the improved circuit model allowed to

  13. Transient stability enhancement of electric power generating systems by 120-degree phase rotation

    DOEpatents

    Cresap, Richard L.; Taylor, Carson W.; Kreipe, Michael J.

    1982-01-01

    A method and system for enhancing the transient stability of an intertied three-phase electric power generating system. A set of power exporting generators (10) is connected to a set of power importing generators (20). When a transient cannot be controlled by conventional stability controls, and imminent loss of synchronism is detected (such as when the equivalent rotor angle difference between the two generator sets exceeds a predetermined value, such as 150 degrees), the intertie is disconnected by circuit breakers. Then a switch (30) having a 120-degree phase rotation, or a circuit breaker having a 120-degree phase rotation is placed in the intertie. The intertie is then reconnected. This results in a 120-degree reduction in the equivalent rotor angle difference between the two generator sets, making the system more stable and allowing more time for the conventional controls to stabilize the transient.

  14. Multipurpose Vacuum Induction Processing System

    NASA Astrophysics Data System (ADS)

    Govindaraju, M.; Kulkarni, Deepak; Balasubramanian, K.

    2012-11-01

    Multipurpose vacuum processing systems are cost effective; occupy less space, multiple functional under one roof and user friendly. A multipurpose vacuum induction system was designed, fabricated and installed in a record time of 6 months time at NFTDC Hyderabad. It was designed to function as a) vacuum induction melting/refining of oxygen free electronic copper/pure metals, b) vacuum induction melting furnace for ferrous materials c) vacuum induction melting for non ferrous materials d) large vacuum heat treatment chamber by resistance heating (by detachable coil and hot zone) e) bottom discharge vacuum induction melting system for non ferrous materials f) Induction heat treatment system and g) directional solidification /investment casting. It contains provision for future capacity addition. The attachments require to manufacture multiple shaped castings and continuous rod casting can be added whenever need arises. Present capacity is decided on the requirement for 10years of development path; presently it has 1.2 ton liquid copper handling capacity. It is equipped with provision for capacity addition up to 2 ton liquid copper handling capacity in future. Provision is made to carry out the capacity addition in easy steps quickly. For easy operational maintenance and troubleshooting, design was made in easily detachable sections. High vacuum system is also is detachable, independent and easily movable which is first of its kind in the country. Detailed design parameters, advantages and development history are presented in this paper.

  15. Vacuum leak detector and method

    DOEpatents

    Edwards, Jr., David

    1983-01-01

    Apparatus and method for detecting leakage in a vacuum system involves a moisture trap chamber connected to the vacuum system and to a pressure gauge. Moisture in the trap chamber is captured by freezing or by a moisture adsorbent to reduce the residual water vapor pressure therein to a negligible amount. The pressure gauge is then read to determine whether the vacuum system is leaky. By directing a stream of carbon dioxide or helium at potentially leaky parts of the vacuum system, the apparatus can be used with supplemental means to locate leaks.

  16. Robot design for a vacuum environment

    NASA Technical Reports Server (NTRS)

    Belinski, S.; Trento, W.; Imani-Shikhabadi, R.; Hackwood, S.

    1987-01-01

    The cleanliness requirements for many processing and manufacturing tasks are becoming ever stricter, resulting in a greater interest in the vacuum environment. Researchers discuss the importance of this special environment, and the development of robots which are physically and functionally suited to vacuum processing tasks. Work is in progress at the Center for robotic Systems in Microelectronics (CRSM) to provide a robot for the manufacture of a revolutionary new gyroscope in high vacuum. The need for vacuum in this and other processes is discussed as well as the requirements for a vacuum-compatible robot. Finally, researchers present details on work done at the CRSM to modify an existing clean-room compatible robot for use at high vacuum.

  17. An Experimental Study of Droplets Produced by a Plunging Breakers

    NASA Astrophysics Data System (ADS)

    Erinin, Martin; Wang, Dan; Towle, David; Liu, Xinan; Duncan, James

    2016-11-01

    In this study, the production of droplets by a mechanically generated plunging breaking water wave is investigated in a wave tank. The breaker, with an amplitude of 0.070 m, is generated repeatedly with a programmable wave maker by using a dispersively focused wave packet (average frequency 1.15 Hz). The profile histories of the breaking wave crests along the center plane of the tank are measured using cinematic laser-induced fluorescence. The droplets are measured using a cinematic digital in-line holographic system positioned at 30 locations along a horizontal plane that is 1 cm above the maximum wave crest height. This measurement plane covers the entire region in the tank where the wave breaks. The holographic system is used to obtain the droplet diameters (d, for d >100 microns) and the three components of the droplet velocities. From these measurements and counting only the droplets that are moving up, the spatio-temporal distribution of droplet generation by the breaking wave is obtained. The main features of the droplet generation are correlated with the features and phases of the breaking process. The support of the National Science Foundation under Grant OCE0751853 from the Division of Ocean Sciences is gratefully acknowledged.

  18. 40 CFR 63.685 - Standards: Tanks.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... organic-contaminated debris is dumped from roll-off boxes or dump trucks, and then this debris is promptly... roof except for automatic bleeder vents (vacuum breaker vents) and the rim space vents is to provide a... gasketed cover or a gasketed lid except for leg sleeves, automatic bleeder vents, rim space vents, column...

  19. 40 CFR 63.685 - Standards: Tanks.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... organic-contaminated debris is dumped from roll-off boxes or dump trucks, and then this debris is promptly... roof except for automatic bleeder vents (vacuum breaker vents) and the rim space vents is to provide a... gasketed cover or a gasketed lid except for leg sleeves, automatic bleeder vents, rim space vents, column...

  20. 40 CFR 63.685 - Standards: Tanks.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... organic-contaminated debris is dumped from roll-off boxes or dump trucks, and then this debris is promptly... roof except for automatic bleeder vents (vacuum breaker vents) and the rim space vents is to provide a... gasketed cover or a gasketed lid except for leg sleeves, automatic bleeder vents, rim space vents, column...

  1. 40 CFR 63.685 - Standards: Tanks.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... organic-contaminated debris is dumped from roll-off boxes or dump trucks, and then this debris is promptly... roof except for automatic bleeder vents (vacuum breaker vents) and the rim space vents is to provide a... gasketed cover or a gasketed lid except for leg sleeves, automatic bleeder vents, rim space vents, column...

  2. Microfabrication and Cold Testing of Copper Circuits for a 50 Watt, 220 GHz Traveling Wave Tube

    DTIC Science & Technology

    2013-01-11

    Dobbs, R. J., Joye, C. D., Kory, C. L., Neil, G. R., Park, G. S ., Park, J. H., Temkin, R. J., “Vacuum electronic high power terahertz sources,” Trans...Steer, B., Hyttinen, M., Roitman, A., Horoyski, P., Smith, G. M., Bolton, D. R., Cruickshank, P. A. S ., Robertson, D. A., "Compact, high power EIK...precise circuits with high yield. It was found that slight beam tunnel misalignment can cause very strong stopbands to appear in the operating band

  3. ADDER CIRCUIT

    DOEpatents

    Jacobsohn, D.H.; Merrill, L.C.

    1959-01-20

    An improved parallel addition unit is described which is especially adapted for use in electronic digital computers and characterized by propagation of the carry signal through each of a plurality of denominationally ordered stages within a minimum time interval. In its broadest aspects, the invention incorporates a fast multistage parallel digital adder including a plurality of adder circuits, carry-propagation circuit means in all but the most significant digit stage, means for conditioning each carry-propagation circuit during the time period in which information is placed into the adder circuits, and means coupling carry-generation portions of thc adder circuit to the carry propagating means.

  4. Technical specification for vacuum systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Khaw, J.

    The vacuum systems at the Stanford Linear Accelerator Center (SLAC) are primarily of all-metal construction and operate at pressures from 10/sup -5/ to 10/sup -11/ Torr. The primary gas loads during operation result from thermal desorption and beam-induced desorption from the vacuum chamber walls. These desorption rates can be extremely high in the case of hydrocarbons and other contaminants. These specifications place a major emphasis on eliminating contamination sources. The specifications and procedures have been written to insure the cleanliness and vacuum integrity of all SLAC vacuum systems, and to assist personnel involved with SLAC vacuum systems in choosing andmore » designing components that are compatible with existing systems and meet the quality and reliability of SLAC vacuum standards. The specification includes requirements on design, procurement, fabrication, chemical cleaning, clean room practices, welding and brazing, helium leak testing, residual gas analyzer testing, bakeout, venting, and pumpdown. Also appended are specifications regarding acceptable vendors, isopropyl alcohol, bakeable valve cleaning procedure, mechanical engineering safety inspection, notes on synchrotron radiation, and specifications of numerous individual components. (LEW)« less

  5. Color Coding of Circuit Quantities in Introductory Circuit Analysis Instruction

    ERIC Educational Resources Information Center

    Reisslein, Jana; Johnson, Amy M.; Reisslein, Martin

    2015-01-01

    Learning the analysis of electrical circuits represented by circuit diagrams is often challenging for novice students. An open research question in electrical circuit analysis instruction is whether color coding of the mathematical symbols (variables) that denote electrical quantities can improve circuit analysis learning. The present study…

  6. Design of an improved RCD buffer circuit for full bridge circuit

    NASA Astrophysics Data System (ADS)

    Yang, Wenyan; Wei, Xueye; Du, Yongbo; Hu, Liang; Zhang, Liwei; Zhang, Ou

    2017-05-01

    In the full bridge inverter circuit, when the switch tube suddenly opened or closed, the inductor current changes rapidly. Due to the existence of parasitic inductance of the main circuit. Therefore, the surge voltage between drain and source of the switch tube can be generated, which will have an impact on the switch and the output voltage. In order to ab sorb the surge voltage. An improve RCD buffer circuit is proposed in the paper. The peak energy will be absorbed through the buffer capacitor of the circuit. The part energy feedback to the power supply, another part release through the resistor in the form of heat, and the circuit can absorb the voltage spikes. This paper analyzes the process of the improved RCD snubber circuit, According to the specific parameters of the main circuit, a reasonable formula for calculating the resistance capacitance is given. A simulation model will be modulated in Multisim, which compared the waveform of tube voltage and the output waveform of the circuit without snubber circuit with the improved RCD snubber circuit. By comparing and analyzing, it is proved that the improved buffer circuit can absorb surge voltage. Finally, experiments are demonstrated to validate that the correctness of the RC formula and the improved RCD snubber circuit.

  7. Bakeout Chamber Within Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Taylor, Daniel M.; Soules, David M.; Barengoltz, Jack B.

    1995-01-01

    Vacuum-bakeout apparatus for decontaminating and measuring outgassing from pieces of equipment constructed by mounting bakeout chamber within conventional vacuum chamber. Upgrade cost effective: fabrication and installation of bakeout chamber simple, installation performed quickly and without major changes in older vacuum chamber, and provides quantitative data on outgassing from pieces of equipment placed in bakeout chamber.

  8. Adaptive protection algorithm and system

    DOEpatents

    Hedrick, Paul [Pittsburgh, PA; Toms, Helen L [Irwin, PA; Miller, Roger M [Mars, PA

    2009-04-28

    An adaptive protection algorithm and system for protecting electrical distribution systems traces the flow of power through a distribution system, assigns a value (or rank) to each circuit breaker in the system and then determines the appropriate trip set points based on the assigned rank.

  9. 49 CFR 238.305 - Interior calendar day mechanical inspection of passenger cars.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., circuit breakers, contactors, relays, grid resistors, and fuses are installed in non-hazardous locations... has access to the record upon request. (2) The written or electronic record must contain the following...) Any non-complying conditions found; and (iv) The signature or electronic identification of the...

  10. 49 CFR 238.305 - Interior calendar day mechanical inspection of passenger cars.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., circuit breakers, contactors, relays, grid resistors, and fuses are installed in non-hazardous locations... has access to the record upon request. (2) The written or electronic record must contain the following...) Any non-complying conditions found; and (iv) The signature or electronic identification of the...

  11. 49 CFR 238.305 - Interior calendar day mechanical inspection of passenger cars.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., circuit breakers, contactors, relays, grid resistors, and fuses are installed in non-hazardous locations... has access to the record upon request. (2) The written or electronic record must contain the following...) Any non-complying conditions found; and (iv) The signature or electronic identification of the...

  12. 75 FR 78783 - Self-Regulatory Organizations; EDGA Exchange, Inc.; Notice of Filing and Immediate Effectiveness...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-16

    ... regarding decisions to pause trading and continue to reduce the negative impacts of sudden, unanticipated price movements in Circuit Breaker Securities. The Exchange believes that the pilot is working well... proposal, the Commission has considered the proposed rule's impact on efficiency, competition, and capital...

  13. A pump driving liquid cooling circuit method for the aperture of an infrared cold optical system

    NASA Astrophysics Data System (ADS)

    Xie, RongJian

    2017-06-01

    To enhance the optical recognition and wavelength filtering of an infrared cold optical system, some lens need to be maintained within a certain temperature range, which requires specific thermal management of the aperture. A 250K liquid cooling circuit designed for this purpose is introduced, and the experimental results established and operated in a vacuum environmental simulation chamber is carried out and analyzed. A practical cooling power source of radiation cooling equipment is adopted and the sun exposure heat load is imitated by array of planar membrane heaters attached on the specific designed structure of the aperture. Controlling the aperture temperature and improving the optical system performance are proved effective. Numerical optimization of the cooling circuit and simulation of the aperture are performed , and the factors affect the optical system performance in the mean time are also investigated.

  14. Improving Vacuum Cleaners

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Under a Space Act Agreement between the Kirby company and Lewis Research Center, NASA technology was applied to a commercial vacuum cleaner product line. Kirby engineers were interested in advanced operational concepts, such as particle flow behavior and vibration, critical factors to improve vacuum cleaner performance. An evaluation of the company 1994 home care system, the Kirby G4, led to the refinement of the new G5 and future models. Under the cooperative agreement, Kirby had access to Lewis' holography equipment, which added insight into how long a vacuum cleaner fan would perform, as well as advanced computer software that can simulate the flow of air through fans. The collaboration resulted in several successes including fan blade redesign and continuing dialogue on how to improve air-flow traits in various nozzle designs.

  15. Vacuum Brazing of Accelerator Components

    NASA Astrophysics Data System (ADS)

    Singh, Rajvir; Pant, K. K.; Lal, Shankar; Yadav, D. P.; Garg, S. R.; Raghuvanshi, V. K.; Mundra, G.

    2012-11-01

    Commonly used materials for accelerator components are those which are vacuum compatible and thermally conductive. Stainless steel, aluminum and copper are common among them. Stainless steel is a poor heat conductor and not very common in use where good thermal conductivity is required. Aluminum and copper and their alloys meet the above requirements and are frequently used for the above purpose. The accelerator components made of aluminum and its alloys using welding process have become a common practice now a days. It is mandatory to use copper and its other grades in RF devices required for accelerators. Beam line and Front End components of the accelerators are fabricated from stainless steel and OFHC copper. Fabrication of components made of copper using welding process is very difficult and in most of the cases it is impossible. Fabrication and joining in such cases is possible using brazing process especially under vacuum and inert gas atmosphere. Several accelerator components have been vacuum brazed for Indus projects at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore using vacuum brazing facility available at RRCAT, Indore. This paper presents details regarding development of the above mentioned high value and strategic components/assemblies. It will include basics required for vacuum brazing, details of vacuum brazing facility, joint design, fixturing of the jobs, selection of filler alloys, optimization of brazing parameters so as to obtain high quality brazed joints, brief description of vacuum brazed accelerator components etc.

  16. 78 FR 23691 - Airworthiness Directives; the Boeing Company

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-22

    ... off electrical power to the in-flight entertainment (IFE) systems and other non-essential electrical...., Washington, DC 20590. FOR FURTHER INFORMATION CONTACT: Ray Mei, Aerospace Engineer, Systems and Equipment... circuit breaker, relays, and wiring to allow the flightcrew to turn off electrical power to the IFE...

  17. Power MEMS Development

    DTIC Science & Technology

    2010-08-31

    circuit breakers for testing and analysis in ONR laboratories. Task 1.2 Contributors: Sunny Kedia, Shinzo Onishi , Scott Samson, Drew Hanser Task 1.2...HEAT SINK FOR HIGH-POWER MEMS SWITCH APPLICATIONS (TASK 1.3) Contributors: Priscila Spagnol, Shinzo Onishi , Drew Hanser, Weidong Wang, Sunny Kedia

  18. 76 FR 50781 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-16

    ... volatility, if adopted, applies]. During the pilot, the term ``Circuit Breaker Securities'' shall mean all.... (collectively, the ``Exchanges''), to pause trading during periods of extraordinary market volatility in S&P 500... extraordinary market volatility, if adopted, applies.\\7\\ On June 23, 2011, the Commission approved the expansion...

  19. Cleaning High-Voltage Equipment With Corncob Grit

    NASA Technical Reports Server (NTRS)

    Caveness, C.

    1986-01-01

    High electrical resistance of particles makes power shutdown unnecessary. New, inexpensive method of cleaning high-voltage electrical equipment uses plentiful agricultural product - corncob grit. Method removes dirt and debris from transformers, circuit breakers, and similar equipment. Suitable for utilities, large utility customers, and electrical-maintenance services.

  20. Discrepancies between Ideal Characteristics of a Property Tax System and Current Practice in New York.

    ERIC Educational Resources Information Center

    Netzer, Dick; Berne, Robert

    1995-01-01

    Ideally, voters' and state legislatures' policy choices should underlie a property tax system that is straightforward, comprehensible, systematic, and reasonably related to policy objectives. Administration should be uniform and fair. New York State's property tax system lacks a uniform valuation standard and "circuit breaker" and has…