WorldWideScience

Sample records for circuit activity control

  1. Genetic control of active neural circuits

    Directory of Open Access Journals (Sweden)

    Leon Reijmers

    2009-12-01

    Full Text Available The use of molecular tools to study the neurobiology of complex behaviors has been hampered by an inability to target the desired changes to relevant groups of neurons. Specific memories and specific sensory representations are sparsely encoded by a small fraction of neurons embedded in a sea of morphologically and functionally similar cells. In this review we discuss genetics techniques that are being developed to address this difficulty. In several studies the use of promoter elements that are responsive to neural activity have been used to drive long lasting genetic alterations into neural ensembles that are activated by natural environmental stimuli. This approach has been used to examine neural activity patterns during learning and retrieval of a memory, to examine the regulation of receptor trafficking following learning and to functionally manipulate a specific memory trace. We suggest that these techniques will provide a general approach to experimentally investigate the link between patterns of environmentally activated neural firing and cognitive processes such as perception and memory.

  2. Controllable circuit

    DEFF Research Database (Denmark)

    2010-01-01

    A switch-mode power circuit comprises a controllable element and a control unit. The controllable element is configured to control a current in response to a control signal supplied to the controllable element. The control unit is connected to the controllable element and provides the control...

  3. An active control synchronization for two modified Chua circuits

    Science.gov (United States)

    Li, Guo-Hui

    2005-03-01

    From modern control theory, an active control method to synchronize two modified Chua circuits with each other, which exhibit chaos, is presented. Some sufficient conditions of linear stability of the chaotic synchronization are obtained from rigorous mathematic justification. On the basis of the state-observer, the controller is analytically deduced using the active control. It is shown that this technique can be applied to achieve synchronization of the two systems with each other, whether they are identical or not. Finally, numerical simulations show the effectiveness of the proposed control scheme.

  4. An active control synchronization for two modified Chua circuits

    Institute of Scientific and Technical Information of China (English)

    Li Guo-Hui

    2005-01-01

    From modern control theory, an active control method to synchronize two modified Chua circuits with each other, which exhibit chaos, is presented. Some sufficient conditions of linear stability of the chaotic synchronization are obtained from rigorous mathematic justification. On the basis of the state-observer, the controller is analytically deduced using the active control. It is shown that this technique can be applied to achieve synchroniztion of the tow systems with each other, whether they are identical or not. Finally, numerical simulations show the effectiveness of the proposed control scheme.

  5. An adaptive active control for the modified Chua's circuit

    International Nuclear Information System (INIS)

    In this Letter, it is shown that a couple of the modified Chua's systems with different parameters and initial conditions can be synchronized using active control when the values of parameters both in drive system and response system are known aforehand. Furthermore, an adaptive active control approach is proposed based on Lyapunov stability theory to make the states of two identical Chua's systems with unknown constant parameters be asymptotically synchronized. In addition, the proposed adaptive active control method guarantees that the designed controller is independent to those uncertain parameters. Simulation results by using both active control and adaptive active control are provided, and the feasibility and effectiveness of the proposed adaptive active control are demonstrated

  6. Transcriptional Regulatory Circuits Controlling Brown Fat Development and Activation

    OpenAIRE

    Seale, Patrick

    2015-01-01

    Brown and beige adipose tissue is specialized for heat production and can be activated to reduce obesity and metabolic dysfunction in animals. Recent studies also have indicated that human brown fat activity levels correlate with leanness. This has revitalized interest in brown fat biology and has driven the discovery of many new regulators of brown fat development and function. This review summarizes recent advances in our understanding of the transcriptional mechanisms that control brown an...

  7. DQ reference frame modeling and control of single-phase active power decoupling circuits

    DEFF Research Database (Denmark)

    Tang, Yi; Qin, Zian; Blaabjerg, Frede; Loh, Poh Chiang

    Power decoupling circuits can compensate the inherent double line frequency ripple power in single-phase systems and greatly facilitate their dc-link capacitor design. Example applications of power decoupling circuit include photovoltaic, light-emitting diode, fuel cell, and motor drive systems....... This paper presents the dq synchronous reference frame modeling of single-phase power decoupling circuits and a complete model describing the dynamics of dc-link ripple voltage is presented. The proposed model is universal and valid for both inductive and capacitive decoupling circuits, and the input...... of decoupling circuits can be either dependent or independent of its front-end converters. Based on this model, a dq synchronous reference frame controller is designed which allows the decoupling circuit to operate in two different modes because of the circuit symmetry. Simulation and experimental...

  8. A novel active T-type three-level converter with open-circuit fault-tolerant control

    DEFF Research Database (Denmark)

    Choi, Uimin; Blaabjerg, Frede

    This paper proposes a novel active T-type three-level converter concept with fault-tolerant control. With the proposed topology, the converter can be operated continuously under open-circuit faults. It is shown that the proposed topology not only can keep its outputs under open-circuit fault......-point devices have the highest thermal stresses. The feasibility and effectiveness of the proposed topology concept are verified by the simulation results....

  9. Optically controllable molecular logic circuits

    International Nuclear Information System (INIS)

    Molecular logic circuits represent a promising technology for observation and manipulation of biological systems at the molecular level. However, the implementation of molecular logic circuits for temporal and programmable operation remains challenging. In this paper, we demonstrate an optically controllable logic circuit that uses fluorescence resonance energy transfer (FRET) for signaling. The FRET-based signaling process is modulated by both molecular and optical inputs. Based on the distance dependence of FRET, the FRET pathways required to execute molecular logic operations are formed on a DNA nanostructure as a circuit based on its molecular inputs. In addition, the FRET pathways on the DNA nanostructure are controlled optically, using photoswitching fluorescent molecules to instruct the execution of the desired operation and the related timings. The behavior of the circuit can thus be controlled using external optical signals. As an example, a molecular logic circuit capable of executing two different logic operations was studied. The circuit contains functional DNAs and a DNA scaffold to construct two FRET routes for executing Input 1 AND Input 2 and Input 1 AND NOT Input 3 operations on molecular inputs. The circuit produced the correct outputs with all possible combinations of the inputs by following the light signals. Moreover, the operation execution timings were controlled based on light irradiation and the circuit responded to time-dependent inputs. The experimental results demonstrate that the circuit changes the output for the required operations following the input of temporal light signals

  10. Optically controllable molecular logic circuits

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Takahiro, E-mail: t-nishimura@ist.osaka-u.ac.jp; Fujii, Ryo; Ogura, Yusuke; Tanida, Jun [Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2015-07-06

    Molecular logic circuits represent a promising technology for observation and manipulation of biological systems at the molecular level. However, the implementation of molecular logic circuits for temporal and programmable operation remains challenging. In this paper, we demonstrate an optically controllable logic circuit that uses fluorescence resonance energy transfer (FRET) for signaling. The FRET-based signaling process is modulated by both molecular and optical inputs. Based on the distance dependence of FRET, the FRET pathways required to execute molecular logic operations are formed on a DNA nanostructure as a circuit based on its molecular inputs. In addition, the FRET pathways on the DNA nanostructure are controlled optically, using photoswitching fluorescent molecules to instruct the execution of the desired operation and the related timings. The behavior of the circuit can thus be controlled using external optical signals. As an example, a molecular logic circuit capable of executing two different logic operations was studied. The circuit contains functional DNAs and a DNA scaffold to construct two FRET routes for executing Input 1 AND Input 2 and Input 1 AND NOT Input 3 operations on molecular inputs. The circuit produced the correct outputs with all possible combinations of the inputs by following the light signals. Moreover, the operation execution timings were controlled based on light irradiation and the circuit responded to time-dependent inputs. The experimental results demonstrate that the circuit changes the output for the required operations following the input of temporal light signals.

  11. 49 CFR 236.13 - Spring switch; selection of signal control circuits through circuit controller.

    Science.gov (United States)

    2010-10-01

    ... circuits through circuit controller. 236.13 Section 236.13 Transportation Other Regulations Relating to...; selection of signal control circuits through circuit controller. The control circuits of signals governing... circuit controller, or through the contacts of relay repeating the position of such circuit...

  12. Light-Controlled Synthetic Gene Circuits

    OpenAIRE

    Gardner, Laura; Deiters, Alexander

    2012-01-01

    Highly complex synthetic gene circuits have been engineered in living organisms to develop systems with new biological properties. A precise trigger to activate or deactivate these complex systems is desired in order to tightly control different parts of a synthetic or natural network. Light represents an excellent tool to achieve this goal as it can be regulated in timing, location, intensity, and wavelength, which allows for precise spatiotemporal control over genetic circuits. Recently, li...

  13. Design and analysis of an active power factor correction circuit

    OpenAIRE

    Zhou, Zhen

    1989-01-01

    The design of an active-unity power factor correction circuit with variable-hysteresis control for off-line dc-to-dc switching power supplies is described. Design equations relating the boost inductor current ripple to the circuit components selection and circuit performance arc discussed. A computer-aided design program (CADO) is developed to give the optimal circuit components selection. A 500 watt, 300 volt experimental circuit is built to verify the simulation and analysis ...

  14. 49 CFR 236.731 - Controller, circuit.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Controller, circuit. A device for opening and closing electric circuits....

  15. 49 CFR 236.721 - Circuit, control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, control. 236.721 Section 236.721 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, control. An electrical circuit between a source of electric energy and a device which it operates....

  16. Activity transport models for PWR primary circuits

    International Nuclear Information System (INIS)

    The corrosion products activated in the primary circuit form a major source of occupational radiation dose in the PWR reactors. Transport of corrosion activity is a complex process including chemistry, reactor physics, thermodynamics and hydrodynamics. All the mechanisms involved are not known and there is no comprehensive theory for the process, so experimental test loops and plant data are very important in research efforts. Several activity transport modelling attempts have been made to improve the water chemistry control and to minimise corrosion in PWR's. In this research report some of these models are reviewed with special emphasis on models designed for Soviet VVER type reactors. (51 refs., 16 figs., 4 tabs.)

  17. 49 CFR 236.5 - Design of control circuits on closed circuit principle.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Design of control circuits on closed circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on closed circuit principle. All control circuits the functioning of which affects safety of train...

  18. Water quality control program in experimental circuits

    International Nuclear Information System (INIS)

    The Water Quality Control Program of the Experimental Circuits visualizes studying the water chemistry of the cooling in the primary and secondary circuits, monitoring the corrosion of the systems and studying the mechanism of the corrosion products transport in the systems. (author)

  19. Timing control by redundant inhibitory neuronal circuits

    Energy Technology Data Exchange (ETDEWEB)

    Tristan, I., E-mail: itristan@ucsd.edu; Rulkov, N. F.; Huerta, R.; Rabinovich, M. [BioCircuits Institute, University of California, San Diego, La Jolla, California 92093-0402 (United States)

    2014-03-15

    Rhythms and timing control of sequential activity in the brain is fundamental to cognition and behavior. Although experimental and theoretical studies support the understanding that neuronal circuits are intrinsically capable of generating different time intervals, the dynamical origin of the phenomenon of functionally dependent timing control is still unclear. Here, we consider a new mechanism that is related to the multi-neuronal cooperative dynamics in inhibitory brain motifs consisting of a few clusters. It is shown that redundancy and diversity of neurons within each cluster enhances the sensitivity of the timing control with the level of neuronal excitation of the whole network. The generality of the mechanism is shown to work on two different neuronal models: a conductance-based model and a map-based model.

  20. Cholinergic Circuit Control of Postnatal Neurogenesis

    Science.gov (United States)

    Asrican, Brent; Paez-Gonzalez, Patricia; Erb, Joshua; Kuo, Chay T.

    2016-01-01

    New neuron addition via continued neurogenesis in the postnatal/adult mammalian brain presents a distinct form of nervous system plasticity. During embryonic development, precise temporal and spatial patterns of neurogenesis are necessary to create the nervous system architecture. Similar between embryonic and postnatal stages, neurogenic proliferation is regulated by neural stem cell (NSC)-intrinsic mechanisms layered upon cues from their local microenvironmental niche. Following developmental assembly, it remains relatively unclear what may be the key driving forces that sustain continued production of neurons in the postnatal/adult brain. Recent experimental evidence suggests that patterned activity from specific neural circuits can also directly govern postnatal/adult neurogenesis. Here, we review experimental findings that revealed cholinergic modulation, and how patterns of neuronal activity and acetylcholine release may differentially or synergistically activate downstream signaling in NSCs. Higher-order excitatory and inhibitory inputs regulating cholinergic neuron firing, and their implications in neurogenesis control are also considered.

  1. Active components for integrated plasmonic circuits

    DEFF Research Database (Denmark)

    Krasavin, A.V.; Bolger, P.M.; Zayats, A.V.;

    2009-01-01

    We present a comprehensive study of highly efficient and compact passive and active components for integrated plasmonic circuit based on dielectric-loaded surface plasmon polariton waveguides.......We present a comprehensive study of highly efficient and compact passive and active components for integrated plasmonic circuit based on dielectric-loaded surface plasmon polariton waveguides....

  2. The peptidergic control circuit for sighing.

    Science.gov (United States)

    Li, Peng; Janczewski, Wiktor A; Yackle, Kevin; Kam, Kaiwen; Pagliardini, Silvia; Krasnow, Mark A; Feldman, Jack L

    2016-02-18

    Sighs are long, deep breaths expressing sadness, relief or exhaustion. Sighs also occur spontaneously every few minutes to reinflate alveoli, and sighing increases under hypoxia, stress, and certain psychiatric conditions. Here we use molecular, genetic, and pharmacologic approaches to identify a peptidergic sigh control circuit in murine brain. Small neural subpopulations in a key breathing control centre, the retrotrapezoid nucleus/parafacial respiratory group (RTN/pFRG), express bombesin-like neuropeptide genes neuromedin B (Nmb) or gastrin-releasing peptide (Grp). These project to the preBötzinger Complex (preBötC), the respiratory rhythm generator, which expresses NMB and GRP receptors in overlapping subsets of ~200 neurons. Introducing either neuropeptide into preBötC or onto preBötC slices, induced sighing or in vitro sigh activity, whereas elimination or inhibition of either receptor reduced basal sighing, and inhibition of both abolished it. Ablating receptor-expressing neurons eliminated basal and hypoxia-induced sighing, but left breathing otherwise intact initially. We propose that these overlapping peptidergic pathways comprise the core of a sigh control circuit that integrates physiological and perhaps emotional input to transform normal breaths into sighs. PMID:26855425

  3. Controllable clock circuit design in PEM system

    International Nuclear Information System (INIS)

    A high-precision synchronized clock circuit design will be presented, which can supply steady, reliable and anti-jamming clock signal for the data acquirement (DAQ) system of Positron Emission Mammography (PEM). This circuit design is based on the Single-Chip Microcomputer and high-precision clock chip, and can achieve multiple controllable clock signals. The jamming between the clock signals can be reduced greatly with the differential transmission. Meanwhile, the adoption of CAN bus control in the clock circuit can prompt the clock signals to be transmitted or masked simultaneously when needed. (authors)

  4. Control circuit for a pulsed neutron source

    International Nuclear Information System (INIS)

    A pulsed neutron source is operated with a control circuit which produces neutron pulses very sharply defined with reference to time. A relatively steep rising high voltage control pulse for the ion source is produced by means of a low voltage input control pulse. Simultaneously, a control pulse is generated for a delayed quenching circuit, which quenches the high voltage control pulse for the ion source after a fixed time delay for a short time. The control voltage obtained for the ion source and for the neutron output is sharply defined as regards time. (orig.)

  5. A model for reverberating circuits with controlled feedback

    Science.gov (United States)

    Rodrigues, Vanessa de Freitas; de Castro, Maria Clícia Stelling; Wedemann, Roseli Suzi; Cortez, Celia Martins

    2015-12-01

    We studied the behavior of a mathematic-computational model for a reverberating neuronal circuit with controlled feedback, verifying the output pattern of the circuit, by means simulations using a program in language C++. Using values obtained from surveying the literature from animal experiments, we observed that the model was able to reproduce the polissynaptic activity of a neuron group of a vigil rat, with looping time of three neurons of the order of magnitude of 102 ms.

  6. TRIAC/SCR proportional control circuit

    Science.gov (United States)

    Hughes, W.J.

    1999-04-06

    A power controller device is disclosed which uses a voltage-to-frequency converter in conjunction with a zero crossing detector to linearly and proportionally control AC power being supplied to a load. The output of the voltage-to frequency converter controls the ``reset`` input of a R-S flip flop, while an ``0`` crossing detector controls the ``set`` input. The output of the flip flop triggers a monostable multivibrator controlling the SCR or TRIAC firing circuit connected to the load. Logic gates prevent the direct triggering of the multivibrator in the rare instance where the ``reset`` and ``set`` inputs of the flip flop are in coincidence. The control circuit can be supplemented with a control loop, providing compensation for line voltage variations. 9 figs.

  7. Feedback control of superconducting quantum circuits

    NARCIS (Netherlands)

    Ristè, D.

    2014-01-01

    Superconducting circuits have recently risen to the forefront of the solid-state prototypes for quantum computing. Reaching the stage of robust quantum computing requires closing the loop between measurement and control of quantum bits (qubits). This thesis presents the realization of feedback contr

  8. The voltage-current relationship and equivalent circuit implementation of parallel flux-controlled memristive circuits

    Institute of Scientific and Technical Information of China (English)

    Bao Bo-Cheng; Feng Fei; Dong Wei; Pan Sai-Hu

    2013-01-01

    A flux-controlled memristor characterized by smooth cubic nonlinearity is taken as an example,upon which the voltage-current relationships (VCRs) between two parallel memristive circuits-a parallel memristor and capacitor circuit (the parallel MC circuit),and a parallel memristor and inductor circuit (the parallel ML circuit)-are investigated.The results indicate that the VCR between these two parallel memristive circuits is closely related to the circuit parameters,and the frequency and amplitude of the sinusoidal voltage stimulus.An equivalent circuit model of the memristor is built,upon which the circuit simulations and experimental measurements of both the parallel MC circuit and the parallel ML circuit are performed,and the results verify the theoretical analysis results.

  9. Design of Threshold Controller Based Chaotic Circuits

    DEFF Research Database (Denmark)

    Mohamed, I. Raja; Murali, K.; Sinha, Sudeshna;

    2010-01-01

    We propose a very simple implementation of a second-order nonautonomous chaotic oscillator, using a threshold controller as the only source of nonlinearity. We demonstrate the efficacy and simplicity of our design through numerical and experimental results. Further, we show that this approach of ...... using a threshold controller as a nonlinear element, can be extended to obtain autonomous and multiscroll chaotic attractor circuits as well....

  10. Volumetric and chemical control auxiliary circuit for a PWR primary circuit

    International Nuclear Information System (INIS)

    The volumetric and chemical control circuit has an expansion tank with at least one water-steam chamber connected to the primary circuit by a sampling pipe and a reinjection pipe. The sampling pipe feeds jet pumps controlled by valves. An action on these valves and pumps regulates the volume of the water in the primary circuit. A safety pipe controlled by a flap automatically injects water from the chamber into the primary circuit in case of ruptures. The auxiliary circuit has also systems for purifying the water and controlling the boric acid and hydrogen content

  11. Measurements of the Effects of Smoke on Active Circuits

    International Nuclear Information System (INIS)

    Smoke has long been recognized as the most common source of fire damage to electrical equipment; however, most failures have been analyzed after the fire was out and the smoke vented. The effects caused while the smoke is still in the air have not been explored. Such effects have implications for new digital equipment being installed in nuclear reactors. The U.S. Nuclear Regulatory Commission is sponsoring work to determine the impact of smoke on digital instrumentation and control. As part of this program, Sandia National Laboratories has tested simple active circuits to determine how smoke affects them. These tests included the study of three possible failure modes on a functional board: (1) circuit bridging, (2) corrosion (metal loss), and (3) induction of stray capacitance. The performance of nine different circuits was measured continuously on bare and conformably coated boards during smoke exposures lasting 1 hour each and continued for 24 hours after the exposure started. The circuit that was most affected by smoke (100% change in measured values) was the one most sensitive to circuit bridging. Its high impedance (50 MOmega) was shorted during the exposure, but in some cases recovered after the smoke was vented. The other two failure modes, corrosion and induced stray capacitance, caused little change in the function of the circuits. The smoke permanently increased resistance of the circuit tested for corrosion, implying that the cent acts were corroded. However, the change was very small (< 2%). The stray-capacitance test circuit showed very little change after a smoke exposure in either the short or long term. The results of the tests suggest that conformal coatings and type of circuit are major considerations when designing digital circuitry to be used in critical control systems

  12. Measurements of the Effects of Smoke on Active Circuits

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.J.

    1999-02-09

    Smoke has long been recognized as the most common source of fire damage to electrical equipment; however, most failures have been analyzed after the fire was out and the smoke vented. The effects caused while the smoke is still in the air have not been explored. Such effects have implications for new digital equipment being installed in nuclear reactors. The U.S. Nuclear Regulatory Commission is sponsoring work to determine the impact of smoke on digital instrumentation and control. As part of this program, Sandia National Laboratories has tested simple active circuits to determine how smoke affects them. These tests included the study of three possible failure modes on a functional board: (1) circuit bridging, (2) corrosion (metal loss), and (3) induction of stray capacitance. The performance of nine different circuits was measured continuously on bare and conformably coated boards during smoke exposures lasting 1 hour each and continued for 24 hours after the exposure started. The circuit that was most affected by smoke (100% change in measured values) was the one most sensitive to circuit bridging. Its high impedance (50 M{Omega}) was shorted during the exposure, but in some cases recovered after the smoke was vented. The other two failure modes, corrosion and induced stray capacitance, caused little change in the function of the circuits. The smoke permanently increased resistance of the circuit tested for corrosion, implying that the cent acts were corroded. However, the change was very small (< 2%). The stray-capacitance test circuit showed very little change after a smoke exposure in either the short or long term. The results of the tests suggest that conformal coatings and type of circuit are major considerations when designing digital circuitry to be used in critical control systems.

  13. Measurements of the effects of smoke on active circuits

    International Nuclear Information System (INIS)

    Smoke has long been recognized as the most common source of fire damage to electrical equipment; however, most failures have been analyzed after the fire was out and the smoke vented. The effects caused while the smoke is still in the air have not been explored. Such effects have implications for new digital equipment being installed in nuclear reactors. The US Nuclear Regulatory Commission is sponsoring work to determine the impact of smoke on digital instrumentation and control. As part of this program, Sandia National Laboratories has tested simple active circuits to determine how smoke affects them. These tests included the study of three possible failure modes on a functional board: (1) circuit bridging, (2) corrosion (metal loss), and (3) induction of stray capacitance. The performance of nine different circuits was measured continuously on bare and conformally coated boards during smoke exposures lasting 1 hour each and continued for 24 hours after the exposure started. The circuit that was most affected by smoke (100% change in measured values) was the one most sensitive to circuit bridging. Its high impedance (50 Mohm) was shorted during the exposure, but in some cases recovered after the smoke was vented. The other two failure modes, corrosion and induced stray capacitance, caused little change in the function of the circuits. The smoke permanently increased resistance of the circuit tested for corrosion, implying that the contacts were corroded. However, the change was very small (< 2%). The stray capacitance test circuit showed very little change after a smoke exposure in either the short or long term. The results of the tests suggest that conformal coatings and type of circuit are major considerations when designing digital circuitry to be used in critical control systems

  14. Designer's handbook of instrumentation and control circuits

    CERN Document Server

    Carr, Joseph J

    1991-01-01

    Here is a comprehensive, practical guide to the entire process of analog instrumentation and control, from sensor input to data conversion circuitry and final output. This readable handbook avoids complex mathematical treatments, instead taking an applications-oriented approach and presenting many sample circuits and concrete examples. It is an essential reference for engineers and high-level technicians in a variety of scientific and engineering fields--anywhere data is collected electronically and where such data is used to control physical processes.Key Features* Covers design o

  15. 49 CFR 236.732 - Controller, circuit; switch.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Controller, circuit; switch. 236.732 Section 236.732 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 236.732 Controller, circuit; switch. A device for opening and closing electric circuits, operated by...

  16. Digital signal processing in power electronics control circuits

    CERN Document Server

    Sozanski, Krzysztof

    2013-01-01

    Many digital control circuits in current literature are described using analog transmittance. This may not always be acceptable, especially if the sampling frequency and power transistor switching frequencies are close to the band of interest. Therefore, a digital circuit is considered as a digital controller rather than an analog circuit. This helps to avoid errors and instability in high frequency components. Digital Signal Processing in Power Electronics Control Circuits covers problems concerning the design and realization of digital control algorithms for power electronics circuits using

  17. Activity-dependent modulation of neural circuit synaptic connectivity

    Directory of Open Access Journals (Sweden)

    Charles R Tessier

    2009-07-01

    Full Text Available In many nervous systems, the establishment of neural circuits is known to proceed via a two-stage process; 1 early, activity-independent wiring to produce a rough map characterized by excessive synaptic connections, and 2 subsequent, use-dependent pruning to eliminate inappropriate connections and reinforce maintained synapses. In invertebrates, however, evidence of the activity-dependent phase of synaptic refinement has been elusive, and the dogma has long been that invertebrate circuits are “hard-wired” in a purely activity-independent manner. This conclusion has been challenged recently through the use of new transgenic tools employed in the powerful Drosophila system, which have allowed unprecedented temporal control and single neuron imaging resolution. These recent studies reveal that activity-dependent mechanisms are indeed required to refine circuit maps in Drosophila during precise, restricted windows of late-phase development. Such mechanisms of circuit refinement may be key to understanding a number of human neurological diseases, including developmental disorders such as Fragile X syndrome (FXS and autism, which are hypothesized to result from defects in synaptic connectivity and activity-dependent circuit function. This review focuses on our current understanding of activity-dependent synaptic connectivity in Drosophila, primarily through analyzing the role of the fragile X mental retardation protein (FMRP in the Drosophila FXS disease model. The particular emphasis of this review is on the expanding array of new genetically-encoded tools that are allowing cellular events and molecular players to be dissected with ever greater precision and detail.

  18. Statistical Estimation of the ,Switching Activity in VLSI Circuits

    OpenAIRE

    Farid N. Najm; Michael G. Xakellis

    1998-01-01

    Higher levels of integration have led to a generation of integrated circuits for which power dissipation and reliability are major design concerns. In CMOS circuits, both of these problems are directly related to the extent of circuit switching activity. The average number of transitions per second at a circuit node is a measure of switching activity that has been called the transition density. This paper presents a statistical simulation technique to estimate individual node transition densi...

  19. A time-delay suppression technique for DPWM control circuit

    OpenAIRE

    Ishizuka, Yoichi; Hirose, Fumitoshi; Yamada, Yusuke; Matsuo, Hirofumi

    2009-01-01

    A proposed design of a low-cost digital pulse width modulation (DPWM) control circuit for non-isolated DC-DC converter without A/D converter is described. Also, propsed real-time PID control technique for DPWM is described. Some experimental results and simulation results are revealed the proposed circuit and scheme. The purpose of this research is striking a balance between minimizing cost increase by digitalizing of the control circuit of DC-DC converter and speeding up the control circuit.

  20. Finite element analysis of the macro fiber composite actuator: macroscopic elastic and piezoelectric properties and active control thereof by means of negative capacitance shunt circuit

    International Nuclear Information System (INIS)

    The finite element method (FEM) model of a piezoelectric macro fiber composite (MFC) is presented. Using a specially developed numerical model, the complete set of macroscopic values of elastic compliance and piezoelectric tensors is computed. These values are useful in numerical FEM simulations of more complex systems such as noise and vibration suppression devices or active acoustic metamaterials, where the MFC actuator can be approximated by a plate-like uniform piezoelectric material. Using this approach, a great reduction of the FEM model complexity can be achieved. The computed numerical macroscopic values of the MFC actuator are compared with MFC manufacturer's data and with data obtained using different computational methods. A demonstration of active tuning of effective elastic constants of the piezoelectric MFC actuator by means of a shunt electric circuit is presented. The effective material constants are computed using the FEM model developed. The effect of the shunt circuit capacitance on the effective anisotropic Young's moduli is analyzed in detail. A method for finding the proper shunt circuit adjustment that yields the maximum values of the MFC actuator Young's modulus is shown. Possible applications to noise and vibration suppression are discussed. (paper)

  1. Cortical feedback control of olfactory bulb circuits.

    Science.gov (United States)

    Boyd, Alison M; Sturgill, James F; Poo, Cindy; Isaacson, Jeffry S

    2012-12-20

    Olfactory cortex pyramidal cells integrate sensory input from olfactory bulb mitral and tufted (M/T) cells and project axons back to the bulb. However, the impact of cortical feedback projections on olfactory bulb circuits is unclear. Here, we selectively express channelrhodopsin-2 in olfactory cortex pyramidal cells and show that cortical feedback projections excite diverse populations of bulb interneurons. Activation of cortical fibers directly excites GABAergic granule cells, which in turn inhibit M/T cells. However, we show that cortical inputs preferentially target short axon cells that drive feedforward inhibition of granule cells. In vivo, activation of olfactory cortex that only weakly affects spontaneous M/T cell firing strongly gates odor-evoked M/T cell responses: cortical activity suppresses odor-evoked excitation and enhances odor-evoked inhibition. Together, these results indicate that although cortical projections have diverse actions on olfactory bulb microcircuits, the net effect of cortical feedback on M/T cells is an amplification of odor-evoked inhibition. PMID:23259951

  2. Test and inspection for process control of monolithic circuits

    Science.gov (United States)

    Spangenberg, E.

    1967-01-01

    Report details the test and inspection procedures for the mass production of high reliability integrated circuits. It covers configuration control, basic fundamentals of quality control, control charts, wafer process evaluation, general process evaluation, evaluation score system, and diffusion evaluation.

  3. New Active Digital Pixel Circuit for CMOS Image Sensor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new active digital pixel circuit for CMOS image sensor is designed consisting of four components: a photo-transducer, a preamplifier, a sample & hold (S & H) circuit and an A/D converter with an inverter. It is optimized by simulation and adjustment based on 2μm standard CMOS process. Each circuit of the components is designed with specific parameters. The simulation results of the whole pixel circuits show that the circuit has such advantages as low distortion, low power consumption, and improvement of the output performances by using an inverter.

  4. Synapse-specific inhibitory control of hippocampal feedback inhibitory circuit

    Directory of Open Access Journals (Sweden)

    Simon eChamberland

    2010-10-01

    Full Text Available Local circuit and long-range GABAergic projections provide powerful inhibitory control over the operation of hippocampal inhibitory circuits, yet little is known about the input- and target-specific organization of interacting inhibitory networks in relation to their specific functions. Using a combination of two-photon laser scanning photostimulation and whole-cell patch clamp recordings in mice hippocampal slices, we examined the properties of transmission at GABAergic synapses formed onto hippocampal CA1 stratum oriens – lacunosum moleculare (O–LM interneurons by two major inhibitory inputs: local projection originating from stratum radiatum interneurons and septohippocampal GABAergic terminals. Optical mapping of local inhibitory inputs to O–LM interneurons revealed that vasoactive intestinal polypeptide- and calretinine-positive neurons, with anatomical properties typical of type III interneuron-specific interneurons, provided the major local source of inhibition to O–LM cells. Inhibitory postsynaptic currents evoked by minimal stimulation of this input exhibited small amplitude and significant paired-pulse and multiple-pulse depression during repetitive activity. Moreover, these synapses failed to show any form of long-term synaptic plasticity. In contrast, synapses formed by septohippocampal projection produced higher amplitude and persistent inhibition and exhibited long-term potentiation induced by theta-like activity. These results indicate the input and target-specific segregation in inhibitory control, exerted by two types of GABAergic projections and responsible for distinct dynamics of inhibition in O–LM interneurons. The two inputs are therefore likely to support the differential activity- and brain state-dependent recruitment of hippocampal feedback inhibitory circuits in vivo, crucial for dendritic disinhibition and computations in CA1 pyramidal cells.

  5. An Activity for Demonstrating the Concept of a Neural Circuit

    Science.gov (United States)

    Kreiner, David S.

    2012-01-01

    College students in two sections of a general psychology course participated in a demonstration of a simple neural circuit. The activity was based on a neural circuit that Jeffress proposed for localizing sounds. Students in one section responded to a questionnaire prior to participating in the activity, while students in the other section…

  6. Integrated-Circuit Controller For Brushless dc Motor

    Science.gov (United States)

    Le, Dong Tuan

    1994-01-01

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

  7. Photonic integrated circuits for radar beam control

    OpenAIRE

    Stulemeijer, J.; Smit, M. K.; Vliet, F.E. van; Bogaart, F.L.M. van den

    1999-01-01

    Photonic integrated circuits have the potential to reduce the volume and weight of optical beamforming networks for phased-array radar antennae by more than one order of magnitude, and will drastically reduce packaging and interconnection costs by integrating subcircuits, consisting of many components, on a single chip. Most work on optical beamforming networks reported so far has been based on discrete optical components. Here we describe a first realization of an integrated optical chip wit...

  8. A NEW CONTROL CIRCUIT AND COMPUTER SOFTWARE FOR CONTROLING PHOTOVOLTAIC SYSTEMS

    OpenAIRE

    Mustafa Berkant SELEK; İŞLER, Yalçın; Metin ÇOLAK

    2008-01-01

    In this study, a new microcontroller circuit was designed and new computer software was implemented to control power flow currents of renewable energy system, which is established in Solar Energy Institute, Ege University, Bornova, Izmir, Turkey. PIC18F452 microcontroller based electronic circuit was designed to control another electronic circuit that includes power electronic switching components. Readily available standard control circuits are designed for switching single level inverters. ...

  9. Efflux Pump Control Alters Synthetic Gene Circuit Function.

    Science.gov (United States)

    Diao, Junchen; Charlebois, Daniel A; Nevozhay, Dmitry; Bódi, Zoltán; Pál, Csaba; Balázsi, Gábor

    2016-07-15

    Synthetic biology aims to design new biological systems for predefined purposes, such as the controlled secretion of biofuels, pharmaceuticals, or other chemicals. Synthetic gene circuits regulating an efflux pump from the ATP-binding cassette (ABC) protein family could achieve this. However, ABC efflux pumps can also drive out intracellular inducer molecules that control the gene circuits. This will introduce an implicit feedback that could alter gene circuit function in ways that are poorly understood. Here, we used two synthetic gene circuits inducible by tetracycline family molecules to regulate the expression of a yeast ABC pump (Pdr5p) that pumps out the inducer. Pdr5p altered the dose-responses of the original gene circuits substantially in Saccharomyces cerevisiae. While one aspect of the change could be attributed to the efflux pumping function of Pdr5p, another aspect remained unexplained. Quantitative modeling indicated that reduced regulator gene expression in addition to efflux pump function could fully explain the altered dose-responses. These predictions were validated experimentally. Overall, we highlight how efflux pumps can alter gene circuit dynamics and demonstrate the utility of mathematical modeling in understanding synthetic gene circuit function in new circumstances. PMID:27111147

  10. Analysis of SCR control circuit testing for power supply double chamber plasma nitriding

    International Nuclear Information System (INIS)

    Analysis of scr control circuit testing for power supply double chamber plasma nitriding has been performed. Analysis of testing was carried out to find out and validate the performance of the SCR control circuit. The testing method is direct measurement consist of oscillator circuit and SCR performance test. The analysis of oscillator circuit with main component of OT UJT 2646 and OT 240 transformer on the SCR control circuit was functioning properly. This can be seen with the formation of the 4 V voltage Vcc as an indication pulse signal to activate the gate on the SCR and at 12 V Vcc voltage (max) pulse signal is almost full. This pulse signal will be used to activate the SCR gate so that the SCR output voltage can be controlled. For SCR that installed on the doubler circuit, they are functioning properly too. The indication is the voltage on the output side of the doubler circuit is almost twice as the input side. The addition of test time (operation time) and the addition of the load current is proportional to the temperature of SCR. (author)

  11. Hybrid circuit modules for motor commutation and control

    Science.gov (United States)

    Dekramer, C.

    1972-01-01

    Thick film hybrid techniques are used to develop circuitry for a brushless dc motor commutator. The power commutator contains the driving circuit and an amplifier that controls the armature current. A position decoder contains digital integrated circuits which receive the signals from the armature position sensors and generate the driving signals for the power commutator in the proper sequence. These units drive motors with stall currents up to about 400 mA.

  12. Neural Control of Energy Balance: Translating Circuits to Therapies

    OpenAIRE

    Gautron, Laurent; Elmquist, Joel K.; Williams, Kevin W

    2015-01-01

    Recent insights into the neural circuits controlling energy balance and glucose homeostasis have rekindled the hope for development of novel treatments for obesity and diabetes. However, many therapies contribute relatively modest beneficial gains with accompanying side effects, and the mechanisms of action for other interventions remain undefined. This Review summarizes current knowledge linking the neural circuits regulating energy and glucose balance with current and potential pharmacother...

  13. Visual experience modulates spatio-temporal dynamics of circuit activation

    Directory of Open Access Journals (Sweden)

    Arianna Maffei

    2011-06-01

    Full Text Available Persistent reduction in sensory drive in early development results in multiple plastic changes of different cortical synapses. How these experience-dependent modifications affect the spatio-temporal dynamics of signal propagation in neocortical circuits is poorly understood. Here we demonstrate that brief visual deprivation significantly affects the propagation of electrical signals in the primary visual cortex. The spatio-temporal spread of circuit activation upon direct stimulation of its input layer (Layer 4 is reduced, as is the activation of Layer 2/3 – the main recipient of the output from Layer 4. Our data suggest that the decrease in spatio-temporal activation of L2/3 depends on reduced L4 output, and is not intrinsically generated within L2/3. The data shown here suggest that changes in the synaptic components of the visual cortical circuit result not only in alteration of local integration of excitatory and inhibitory inputs, but also in a significant decrease in overall circuit activation. Furthermore, our data indicate a differential effect of visual deprivation on L4 and L2/3, suggesting that while feedforward activation of L2/3 is reduced, its activation by long range, within layer inputs is unaltered. Thus, brief visual deprivation induces experience-dependent circuit re-organization by modulating not only circuit excitability, but also the spatio-temporal patterns of cortical activation within and between layers.

  14. Biasing Circuits for Voltage Controlled GSM Power Amplifiers

    OpenAIRE

    van Bezooijen, André; Prikhodko, Dima; Van Roermund, A.H.M.

    2003-01-01

    In GSM phones voltage controlled power amplifiers are used to vary the output power.Inaccuracies in output power levels are predominantly caused by drift in PA gain over temperature and input power.In this paper we present biasing circuits that implement an inherently accurate gain control curve.These circuits are based on temperature stabilised V/I-converters and current mirrors.Applying current driven biasing of the first RF-stage reduces the input power dependency of the gain.Measurements ...

  15. Visual Experience Modulates Spatio-Temporal Dynamics of Circuit Activation

    OpenAIRE

    Wang, Lang; Fontanini, Alfredo; Maffei, Arianna

    2011-01-01

    Persistent reduction in sensory drive in early development results in multiple plastic changes of different cortical synapses. How these experience-dependent modifications affect the spatio-temporal dynamics of signal propagation in neocortical circuits is poorly understood. Here we demonstrate that brief visual deprivation significantly affects the propagation of electrical signals in the primary visual cortex. The spatio-temporal spread of circuit activation upon direct stimulation of its i...

  16. Visual experience modulates spatio-temporal dynamics of circuit activation

    OpenAIRE

    Arianna Maffei

    2011-01-01

    Persistent reduction in sensory drive in early development results in multiple plastic changes of different cortical synapses. How these experience-dependent modifications affect the spatio-temporal dynamics of signal propagation in neocortical circuits is poorly understood. Here we demonstrate that brief visual deprivation significantly affects the propagation of electrical signals in the primary visual cortex. The spatio-temporal spread of circuit activation upon direct stimulation of its i...

  17. Circuit Design: An inquiry lab activity at Maui Community College

    OpenAIRE

    Morzinski, Katie; Azucena, Oscar; Downs, Cooper; Favaloro, Tela; Park, Jung; U, Vivian

    2010-01-01

    We present an inquiry lab activity on Circuit Design that was conducted in Fall 2009 with first-year community college students majoring in Electrical Engineering Technology. This inquiry emphasized the use of engineering process skills, including circuit assembly and problem solving, while learning technical content. Content goals of the inquiry emphasized understanding voltage dividers (Kirchoff's voltage law) and analysis and optimization of resistive networks (Thevenin equivalence). We as...

  18. Circuit Design: An inquiry lab activity at Maui Community College

    CERN Document Server

    Morzinski, Katie; Downs, Cooper; Favaloro, Tela; Park, Jung; U, Vivian

    2010-01-01

    We present an inquiry lab activity on Circuit Design that was conducted in Fall 2009 with first-year community college students majoring in Electrical Engineering Technology. This inquiry emphasized the use of engineering process skills, including circuit assembly and problem solving, while learning technical content. Content goals of the inquiry emphasized understanding voltage dividers (Kirchoff's voltage law) and analysis and optimization of resistive networks (Thevenin equivalence). We assumed prior exposure to series and parallel circuits and Ohm's law (the relationship between voltage, current, and resistance) and designed the inquiry to develop these skills. The inquiry utilized selection of engineering challenges on a specific circuit (the Wheatstone Bridge) to realize these learning goals. Students generated questions and observations during the starters, which were categorized into four engineering challenges or design goals. The students formed teams and chose one challenge to focus on during the i...

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

    Science.gov (United States)

    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.

  20. Control of electrostatic damage to electronic circuits

    Energy Technology Data Exchange (ETDEWEB)

    Kirk, W.J. Jr.

    1980-03-01

    Static is caused by the flow of materials and people within an environment. The static voltages generated by these movements can degrade or destroy many solid state devices currently being used in sophisticated electronic equipment. Discharge of static voltages through these sensitive devices during assembly operations can lead to a nonfunctional assembly fabricated from parts which previously were acceptable or to later failure of an assembly which was functional after fabrication. Sources of electrostatic charges, equipment and methods for minimizing the generation of electrostatic voltages during the production, assembly and packaging of solid state electronic equipment, and the sensitivity of solid state devices to electrostatic damage are discussed. It is concluded that static awareness is the key to an effective electrostatic damage (ESD) control program, and that production facilities must incorporate electrostatic protection facilities, materials, and processes so that workers can concentrate on producing a high-quality product without having to be overly concerned about ESD procedures. (LCL)

  1. Control technology for integrated circuit fabrication at Micro-Circuit Engineering, Incorporated, West Palm Beach, Florida

    Science.gov (United States)

    Mihlan, G. I.; Mitchell, R. I.; Smith, R. K.

    1984-07-01

    A survey to assess control technology for integrated circuit fabrication was conducted. Engineering controls included local and general exhaust ventilation, shielding, and personal protective equipment. Devices or work stations that contained toxic materials that were potentially dangerous were controlled by local exhaust ventilation. Less hazardous areas were controlled by general exhaust ventilation. Process isolation was used in the plasma etching, low pressure chemical vapor deposition, and metallization operations. Shielding was used in ion implantation units to control X-ray emissions, in contact mask alignes to limit ultraviolet (UV) emissions, and in plasma etching units to control radiofrequency and UV emissions. Most operations were automated. Use of personal protective equipment varied by job function.

  2. Nonlinear Magnetic Circuit Analysis of SMART Control Rod Drive Actuator

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Myounggyu; Gi, Myung Ju; Kim, Myounggon; Park, Youngwoo [Chungnam Nat' l Univ., Daejeon (Korea, Republic of); Lee, Jaeseon; Kim, Jongwook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this paper, we derive a nonlinear magnetic circuit model of an electromagnetic control-rod actuator in the SMART. The results of the nonlinear model are compared with those by linear circuit model and finite-element analyses. gnetic circuit modeling is a useful tool when designing an electromagnetic actuator, as it allows fast calculations and enables parametric studies. It is particularly essential when the actuator is to be used in a very complex system such as a nuclear reactor. Important design parameters must be identified at the early stage of the design process. Once the design space is narrowed down, more accurate methods such finite-element analyses (FEA) can be employed for detailed design. Magnetic circuit modeling is based on the assumption that a flux path consists of sections in each of which field quantities are constant with linear constitutive relations. This assumption fails to hold when portions of the flux path become saturated. The magnetic circuit must be modified in order to accurately describe the nonlinear behavior of saturation.

  3. Nonlinear Magnetic Circuit Analysis of SMART Control Rod Drive Actuator

    International Nuclear Information System (INIS)

    In this paper, we derive a nonlinear magnetic circuit model of an electromagnetic control-rod actuator in the SMART. The results of the nonlinear model are compared with those by linear circuit model and finite-element analyses. gnetic circuit modeling is a useful tool when designing an electromagnetic actuator, as it allows fast calculations and enables parametric studies. It is particularly essential when the actuator is to be used in a very complex system such as a nuclear reactor. Important design parameters must be identified at the early stage of the design process. Once the design space is narrowed down, more accurate methods such finite-element analyses (FEA) can be employed for detailed design. Magnetic circuit modeling is based on the assumption that a flux path consists of sections in each of which field quantities are constant with linear constitutive relations. This assumption fails to hold when portions of the flux path become saturated. The magnetic circuit must be modified in order to accurately describe the nonlinear behavior of saturation

  4. Low Pressure Circuit Control and adjust System Test

    International Nuclear Information System (INIS)

    The hydraulic mechanism (MSAC) is a system that will be employed in the movement of the control rods of the CAREM-25 reactor.In this report, the experimental work on a prototype of MSAC in a low pressure circuit is presented: also the methodology and conclusions.Basic thermalhydraulic data from the MSAC was obtained, and the most relevant control parameters were determined.The response of the mechanism to changes in the control parameters was also evaluated. In conclusion, the response of the MSAC fulfills the aspects of reliability and repetitive movement with water flow pulses control, in the low pressure circuit at the Laboratorio de Mecanica, Materiales y Mediciones of INVAP S.E

  5. Comparison of bidirectional power electronics with unidirectional topologies using active discharging circuits for feeding DEAP transducer

    Science.gov (United States)

    Hoffstadt, Thorben; Maas, Jürgen

    2015-04-01

    To enable a continuous operation of a DEAP transducer, the feeding power electronics must provide the capability to charge and discharge the transducer to enable a continuous voltage adjustment. While in case of energy harvesting applications a bidirectional power electronics is mandatory, for actuator applications also unidirectional power electronics with active discharging circuits can be used. Thus, in this contribution a bidirectional flyback-converter is compared to a unidirectional with different discharging circuits. For this purpose, the design of a resistive and an inductive-resistive discharging circuit is proposed, that are connected in parallel to the DEAP and activated when required. Modulation schemes for both discharging circuits are derived that enable a continuous voltage control. Based on realized prototypes of the investigated topologies the different converters are finally compared to each other.

  6. Dynorphin Controls the Gain of an Amygdalar Anxiety Circuit

    OpenAIRE

    Nicole A. Crowley; Daniel W. Bloodgood; J. Andrew Hardaway; Alexis M. Kendra; Jordan G. McCall; Ream Al-Hasani; Nora M. McCall; Waylin Yu; Zachary L. Schools; Michael J. Krashes; Bradford B. Lowell; Jennifer L. Whistler; Michael R. Bruchas; Thomas L. Kash

    2016-01-01

    Kappa opioid receptors (KORs) are involved in a variety of aversive behavioral states, including anxiety. To date, a circuit-based mechanism for KOR-driven anxiety has not been described. Here, we show that activation of KORs inhibits glutamate release from basolateral amygdala (BLA) inputs to the bed nucleus of the stria terminalis (BNST) and occludes the anxiolytic phenotype seen with optogenetic activation of BLA-BNST projections. In addition, deletion of KORs from amygdala neurons results...

  7. Retrofitting the instrumentation and control system of primary cooling circuit from TRIGA INR 14 MW reactor

    International Nuclear Information System (INIS)

    Activities of retrofitting the instrumentation and control system from TRIGA INR primary cooling circuit consists in replacement of actual system for: - parameter measurement; - safety; - reactor external scramming; - protection, command and supply for electrical elements of the system. This retrofitting project is designed to ensure the necessary features of reactor external safety and for technological parameter measurement. The new safety system of main cooling circuit is completely separated from its operating system and is arranged in a panel assembly in reactor control room. The operating system has the following features: - data acquisition; - parameter value and state of command elements displaying; - command elements on hierarchical levels; - operator information through visual and acoustic alarm. (authors)

  8. Switching regulator emission control circuit for ion sources

    Science.gov (United States)

    Clay, F. P., Jr.; Brock, F. J.; Melfi, L. T., Jr.

    1975-01-01

    An electron emission control circuit of the switching regulator type operating at 100 kHz has been developed which maintains a constant emission current within 0.1% for a cathode power demand variation of approximately 100%. The power output stage has an efficiency of 67%, and the overall efficiency is 45% when driving a thoria-coated iridium cathode having a nominal resistance at operating temperature of 2.5 ohms. Under optimum conditions, the bus power demand is 1.75 W. The circuit is useful in controlling the electron emission current of ion sources in applications which involve a substantial variation of the cathode work function, such as oxygen partial pressure measurements over a large dynamic range.

  9. Stepping Motors and Associated Electronic Circuits for Reactor Control

    International Nuclear Information System (INIS)

    Electrical stepping motors are now available which, because of their high torque and precise motion, are very suitable for use with reactor control rods. A typical motor will produce a torque of about 30 kg cm at 10 rev/min and make about 150 steps per revolution, so that a positional accuracy of 1 part in 10000 can be obtained on the control absorber. The motors may have three or four windings and are driven by d.c. pulse-generators specially designed for the particular reactor application. The low-frequency pulses may be produced in many ways, including: (a) rotating shutters moving over photo-transistors, (b) assemblies of standard computing elements, such as synchro-transmitters, and (c) circuits which cause frequency-reduction and squaring of the 50 c/s or 60 c/s electrical supply. It is advisable to arrange variation of the on/off ratio of pulses to obtain maximum torque or reduce energy losses in the motors. The usual electronic circuit consists of binary frequency-dividing circuits connected to Schmitt trigger circuits which switch a low-voltage d.c. supply to the motors via transistor amplifiers. A typical design will permit an absorber to be driven in steps over 60 cm in 5, 10, 20, 40, 80 or 100 min in the direction required. In the electronic circuits, separate channels are used for each speed and direction to give high reliability and solid-state components on portable cards are used throughout for ease of maintenance. Auto control may be applied, by using a two-phase motor to drive a rotary pulse-generator or by means of frequency- modulation about a chosen reference. It is convenient to measure position by displaying the number of pulses fed to the motor on a two-way counter. Various monitoring circuits may be used to verify that the motor has moved in the correct direction and the use of groups of three or more units permits redundancy principles to be applied. Six vertically-acting control rods with stepping motors will be installed in the high

  10. Mathematic-Graphical Formalization of Switch Point Control Circuit Function

    Directory of Open Access Journals (Sweden)

    Juraj Zdansky

    2004-01-01

    Full Text Available This article describes authors designed method then enables mathematic – graphical formalization of system’s functional specification. The result of this method is algebraic system – finite automata that is written in transition table. This transition table is possible to overwrite to graphic form (state diagram or to mathematic form (transition and output function. This method is described by example of switch point control circuit.

  11. A cortical circuit for gain control by behavioral state

    OpenAIRE

    Fu, Yu; Tucciarone, Jason M.; Espinosa, J. Sebastian; Sheng, Nengyin; Darcy, Daniel P.; Nicoll, Roger A.; Huang, Z. Josh; Stryker, Michael P

    2014-01-01

    The brain’s response to sensory input is strikingly modulated by behavioral state. Notably, the visual response of mouse primary visual cortex (V1) is enhanced by locomotion, a tractable and accessible example of a time-locked change in cortical state. The neural circuits that transmit behavioral state to sensory cortex to produce this modulation are unknown. In vivo calcium imaging of behaving animals revealed that locomotion activates vasoactive intestinal peptide (VIP)-positive neurons in ...

  12. Activity-dependent modulation of neural circuit synaptic connectivity

    OpenAIRE

    Tessier, Charles R.; Kendal Broadie

    2009-01-01

    In many nervous systems, the establishment of neural circuits is known to proceed via a two-stage process; 1) early, activity-independent wiring to produce a rough map characterized by excessive synaptic connections, and 2) subsequent, use-dependent pruning to eliminate inappropriate connections and reinforce maintained synapses. In invertebrates, however, evidence of the activity-dependent phase of synaptic refinement has been elusive, and the dogma has long been that invertebrate circ...

  13. Automatic safety control for a reactor primary circuit

    International Nuclear Information System (INIS)

    It is to be provided for the circulation in a closed-loop primary coolant circuit of a nuclear reactor driven by a recirculation pump to stop instantaneously without any action of additional control systems on occurence of a large pressure drop. The recirculation pumps operating without cavitation at the operating point is designed according to the invention in that way that at large pressure drops in the coolant circuit it wille pass over to full cavitation, thus reducing the flow rate to a flow per cent of the operating flow rate. This is achieved by influencing a) the distribution of the required total pressure head of the recirculation pump over the total range of flow rates, or b) the pressure head excisting on the suction side of the recirculation pump. Both means may also be applied together. (RW) 891 RW/RW 892 MKO

  14. Solid state circuit controls direction, speed, and braking of dc motor

    Science.gov (United States)

    Hanna, M. F.

    1966-01-01

    Full-wave bridge rectifier circuit controls the direction, speed, and braking of a dc motor. Gating in the circuit of Silicon Controlled Rectifiers /SCRS/ controls output polarity and braking is provided by an SCR that is gated to short circuit the reverse voltage generated by reversal of motor rotation.

  15. FPGA based control circuit for single phase inverter

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, M.I.; Husin, Z.; Abd Rahim, H.; Abu Hassan, M.S. [Malaysia Perlis Univ., Perlis (Malaysia). School of Computer and Communication Engineering; Ismail, B. [Malaysia Perlis Univ., Perlis (Malaysia). School of Microelectronic Engineering; Isa, M.N. [Malaysia Perlis Univ., Perlis (Malaysia). School of Power System Engineering

    2008-07-01

    A study was conducted in which DC voltage was successfully converted to a pure sine wave AC source. This paper described the controller circuit for a single phase inverter, which was used to convert DC to AC voltage. Inverters typically have various switching techniques, depending on the application, such as emergency lighting systems, AC variable speed drives, uninterrupted power supplies and frequency converters. The techniques include pulse width modulation, sinusoidal pulse width modulation (SPWM) and modified SPWM. In this study, the circuitry of the SPWM inverter was constructed using power MOSFET. However, it could also be constructed using other power semiconductor devices such as a bipolar junction transistor or an insulated gate bipolar transistor. A low cost, field programmable gate array FPGA chip developed by Altera was used as the main controller unit to control the operation of the full bridge circuit and generate a control signal for SPWM. The whole control unit consisted of 1734 logic elements. The high logic density of the FPGA chip served as an efficient hardware for rapid prototyping. As such, the use of the FPGA increased signal accuracy. The output was a pure sine wave of 242 volt rms with low harmonics distortion which is less than 3 per cent. This is suitable for use in complex electrical equipment and frequency sensitive equipment. 4 refs., 1 tab., 8 figs.

  16. RECONFIGURING EVOLVED CIRCUITS USING CONTROLLER: A REAL TIME APPROACH

    Directory of Open Access Journals (Sweden)

    B. Hari Krishna

    2014-01-01

    Full Text Available FPGA is a device that contains a matrix of reconfigurable gate arrays that can implement different complex functions and also vary structurally. In this study, a novel method of reconfigurable circuit switching action is done with the help of a controller. BPSK Modulation application is chosen to demonstrate the reconfigurable action. When an event occurs the context/core switching is done at both input and output and also preserving the structural and functional relationship. The reconfiguration ability of FPGA with an embedded core performing the switching in real time is the focus of this study. A controller running on Linux platform is used along with the FPGA core. In this study, we propose a real time approach for reconfiguring evolved circuits using controller. It has an adaptive hardware that can continuously change in response to the input data and there by perform reconfiguration. Here the reconfiguration process is achieved by using a real time controller which gives a command to the FPGA core (ALTERA (Cypress processor for reconfiguration.

  17. Comprehensive figures of merit for passive and active plasmonic circuits

    OpenAIRE

    Krasavin, Alexey V.; Zayats, Anatoly V.

    2015-01-01

    In this article a comprehensive figures of merit for both passive and active plasmonic circuit components are introduced, benchmarking their performance for the realisation of high-bandwidth optical data communication in electronic chips. For the first time the figure of merit for passive plasmonic interconnects has been derived in terms of ultimate global characteristics of the plasmonic circuitry, particularly bandwidth and power consumption densities. Then, these parameters were linked to ...

  18. Design of Greenhouse Temperature and Light Intensity Control Circuit

    Institute of Scientific and Technical Information of China (English)

    Chao; ZHANG

    2014-01-01

    In view of domestic scientific and technological achievements at present,real-time control circuit for greenhouse temperature and light intensity has been designed in line with the principle of cost saving and easy control.With advanced temperature sensor and light sensor applied to measure the temperature and light intensity,an execution unit is controlled by single-chip microcomputer(SCM)to regulate the temperature and light intensity,creating a hardware design scheme and software design idea.In case of high temperature and high light intensity in greenhouse,the sunshade net will be put down and the blower will be started automatically;in case of low temperature and light intensity,the sunshade net will be folded up and the heating valve will be turned up automatically.In this way,the temperature and light intensity in greenhouse will be controlled within the designed range.

  19. Tools for Resolving Functional Activity and Connectivity within Intact Neural Circuits

    OpenAIRE

    Jennings, Joshua H.; Stuber, Garret D.

    2014-01-01

    Mammalian neural circuits are sophisticated biological systems that choreograph behavioral processes vital for survival. While the inherent complexity of discrete neural circuits has proven difficult to decipher, many parallel methodological developments promise to help delineate the function and connectivity of molecularly defined neural circuits. Here, we review recent technological advances designed to precisely monitor and manipulate neural circuit activity. We propose a holistic, multifa...

  20. Research and design of the protection circuits in LD controller

    Institute of Scientific and Technical Information of China (English)

    SHAN Jiang-dong; TIAN Xiao-jian; DENG Jun; ZHANG Shuang

    2006-01-01

    According to the parameters and applications of laser diode (LD), three protection circuits were designed: the time-delay soft-start protection circuit, the power-on impulse protection circuit and the limit-current protection circuit. In this article, the structure and the principle of every protection circuit have been detailed. From several tests and feedbacks from customers, the expected goals have been completed.

  1. Dynamic phases in control and information processing biological circuits

    Science.gov (United States)

    Vaikuntanathan, Suriyanarayanan

    2015-03-01

    Recent work using the mathematical framework of large deviation theory has shown that fluctuations about the steady state can have a particularly rich structure even in extremely simple non-equilibrium systems [Phys. Rev. E. 89, 062108, 2014]. In certain instances the fluctuations can encode the presence of a dynamical phase with properties distinct from those of the steady state of the system. The transition between these two regimes is akin to a first order thermodynamic phase transition. Specifically, it implies an extreme sensitivity of the system to changes in certain sets of parameters. I will show that such dynamical phase transitions can serve as a general organizing principle to understand biological circuits that are involved in information processing and control. I will focus on two specific examples: adaptation control in E. coli chemotaxis and ultra sensitive response of the E. coli flagella motor, to illustrate these calculations. This work also elucidates the role played by energy dissipation in ensuring control and suggests general guidelines for the construction of robust non equilibrium circuits that perform various specified functions.

  2. Quantum circuits with uniformly controlled one-qubit gates

    International Nuclear Information System (INIS)

    Uniformly controlled one-qubit gates are quantum gates which can be represented as direct sums of two-dimensional unitary operators acting on a single qubit. We present a quantum gate array which implements any n-qubit gate of this type using at most 2n-1-1 controlled-NOT gates, 2n-1 one-qubit gates, and a single diagonal n-qubit gate. To illustrate the versatility of these gates we then apply them to the decomposition of a general n-qubit gate and a state preparation procedure. Moreover, we study their implementation using only nearest-neighbor gates. We give upper bounds for the one-qubit and controlled-NOT gate counts for all the aforementioned applications. In all four cases, the proposed circuit topologies either improve on or achieve the previously reported upper bounds for the gate counts. Thus, they provide the most efficient method for general gate decompositions currently known

  3. Active Snubber Circuit for High Power Inverter Leg

    DEFF Research Database (Denmark)

    Rasmussen, Tonny Wederberg; Johansen, Morten Holst

    2009-01-01

    Abstract— High power converters in the conventional 6 pulse configuration with 6 switching elements IGBTs (Insulated Gate Bipolar Transistor) are pushed to the limit of power. Especially the switching loss is high. This reduces the switching frequency due to cooling problems. Passive snubber...... circuits have been introduced to reduce the loss even though some of the loss is removed from the IGBT to the snubber resistance. This paper takes also the next step to introduce the active Undeland snubber which in principle is lossless. The paper describes this solution together with some simulations...... indicating that the switching loss is reduced. Comparison between hard switched, passive and active snubber is done....

  4. Balanced calibration of resonant shunt circuits for piezoelectric vibration control

    DEFF Research Database (Denmark)

    Høgsberg, Jan; Krenk, Steen

    2012-01-01

    Shunting of piezoelectric transducers and suitable electric circuits constitutes an effective passive approach to resonant vibration damping of structures. Most common design concepts for resonant resistor-inductor (RL) shunt circuits rely on either maximization of the attainable modal damping...

  5. Towards Defining the Role of CNS Circuits in Control of Energy Homeostasis

    OpenAIRE

    Heß, Simon

    2011-01-01

    Healthy individuals are able to maintain a steady body weight over a long period of time due to an active process called energy homeostasis in which food intake is matched to energy expenditure with great precision. Once this tightly regulated system becomes unbalanced, weight gain and, on a longer time scale, obesity will develop. The control of energy homeostasis is accomplished by neuronal circuits within the CNS. These cir- cuits‚ are able to modulate food intake and energy expenditure in...

  6. Circuit Implementation of Coronary Artery Chaos Phenomenon and Optimal PID Synchronization Controller Design

    Directory of Open Access Journals (Sweden)

    Cheng-Yu Yeh

    2012-01-01

    Full Text Available This study aimed at the implementation and synchronization control of cardiac circuit. First, the MATLAB-Simulink was used to simulate the dynamic behavior of cardiac chaotic circuit, and simple electronic modules were used to implement the cardiac system. Then the Particle Swarm Optimization (PSO was used to seek for the proportional, integral, and derivative gains of optimal PID controller, and the PID controller which could synchronize the slave cardiac circuit and the master cardiac circuit was obtained, in order to synchronize the master/slave chaotic cardiac circuits. This method can be provided for cardiac doctors to diagnose and medicate cardiac abnormality.

  7. Active Match Load Circuit Intended for Testing Piezoelectric Transformers

    DEFF Research Database (Denmark)

    Andersen, Thomas; Rødgaard, Martin Schøler; Andersen, Michael A. E.

    2012-01-01

    An adjustable high voltage active load circuit for voltage amplitudes above 100 volts, especially intended for resistive matching the output impedance of a piezoelectric transformer (PT) is proposed in this paper. PTs have been around for over 50 years, were C. A. Rosen is common known for his...... famous Rosen type design back in the 1950s. After the discovered of new piezoelectric materials and new PT designs have been invented, the PT based power converters are in the area where they can outperform tradition electromagnetic based converters in certain applications. The performance of PTs can...

  8. The PWM auto-control circuit of neutron tube atmospheric pressure

    International Nuclear Information System (INIS)

    Ion source atmospheric pressure auto-control circuit for C/O logging neutron generator is introduced. The pulse circuit of ion source adopts zero-voltage quasi-resonant switch technique and the heating circuit for replenisher adopts PWM converter

  9. Equivalent Circuit for Cavity Discharges Including Controlled Current Source and Controlled Switch

    Institute of Scientific and Technical Information of China (English)

    CHEN Weigen; CHEN Xi; XIE Bo; LIU Jun

    2013-01-01

    Numerous equivalent circuits for cavity discharges have been developed,yet most of these models cannot provide simulated signals that precisely reveal the variability of the discharge's characteristic parameters,such as repetition rate,magnitude and phase of discharges,which makes them not suitable for intensive studies of discharge process.Therefore,using Simulink code,we theoretically analyzed and studied the classical equivalent circuits of cavity discharges,as well as the influence of circuit components on simulation results,and then proposed a novel equivalent circuit,the key parameters of which were determined according to the physical behavior of cavity discharges.In the novel equivalent circuit,the repetition rate can be changed by discharge resistance,inception and residual voltages;meanwhile the phase of discharge can be controlled by adjusting the parameters of shunt resistance.Furthermore,a controlled current source as a function of space charge is introduced in the equivalent circuit.Compared with the former ones,the simulated signals obtained by this novel model are better approximation of real signals.This work could be referred by latter studies of the characteristics and the mechanisms of cavity discharge in oil-paper insulation.

  10. Addiction: Decreased reward sensitivity and increased expectation sensitivity conspire to overwhelm the brain's control circuit

    OpenAIRE

    Volkow, Nora D.; Wang, Gene-Jack; Fowler, Joanna S.; Tomasi, Dardo; Telang, Frank; Baler, Ruben

    2010-01-01

    Based on brain imaging findings, we present a model according to which addiction emerges as an imbalance in the information processing and integration among various brain circuits and functions. The dysfunctions reflect (a) decreased sensitivity of reward circuits, (b) enhanced sensitivity of memory circuits to conditioned expectations to drugs and drug cues, stress reactivity, and (c) negative mood, and a weakened control circuit. Although initial experimentation with a drug of abuse is larg...

  11. Self healing of open circuit faults: With active re-configurability and mimicry of synaptic plasticity

    Science.gov (United States)

    Yaswant, Vaddi; Kumar, Amit; Sambandan, Sanjiv

    2016-07-01

    We discuss the self-repair of open faults in circuits using electrically conductive particles dispersed in an insulating fluid. The repair is triggered by the electric field developed across the open circuit in a current carrying interconnect and results in the formation of a bridge of particles across the gap. We illustrate and model the dynamics of the resistance of the self-healed route, Rb, in low field conditions. Furthermore, active control of Rb and active re-wiring are also demonstrated. Considering Rb to be akin to weights between nodes, the formation and re-wiring of routes and the control of Rb mimic synaptic plasticity in biological systems and open interesting possibilities for computing.

  12. Equivalent realisation circuit for a class of non-ideal voltage-controlled memristors

    Directory of Open Access Journals (Sweden)

    Saihu Pan

    2015-12-01

    Full Text Available In this study, an equivalent realisation circuit with off-the-shelf components and devices is proposed, which can be used to equivalently implement a class of non-ideal voltage-controlled memristors. The mathematical models of the equivalent realisation circuit with three function arithmetic circuits are built and their fingerprints are analysed by the pinched hysteresis loops with bipolar periodic voltage stimuli. The numerical simulations are easily verified by experimental measurements, which indicate that when three function arithmetic circuits are linked, the equivalent realisation circuit can realise three non-ideal voltage-controlled memristors with different non-linearities.

  13. Small-Signal Modeling of Marine Electromagnetic Detection Transmitter Controlled-Source Circuit

    OpenAIRE

    Haijun Tao; Yiming Zhang; Xiguo Ren

    2015-01-01

    Marine electromagnetic transmitter transmits electromagnetic waves with large power frequency conversion to the seabed to obtain the submarine structure and mineral resources. However, the current transmitter presents several problems, such as low efficiency, serious heat, and poor adaptability to the load. Soft-switching controlled-source circuit is used to reduce circuit losses. The mathematical model of controlled-source circuit should be established to realize a closed-loop control for in...

  14. Coupling spatial segregation with synthetic circuits to control bacterial survival.

    Science.gov (United States)

    Huang, Shuqiang; Lee, Anna Jisu; Tsoi, Ryan; Wu, Feilun; Zhang, Ying; Leong, Kam W; You, Lingchong

    2016-02-01

    Engineered bacteria have great potential for medical and environmental applications. Fulfilling this potential requires controllability over engineered behaviors and scalability of the engineered systems. Here, we present a platform technology, microbial swarmbot, which employs spatial arrangement to control the growth dynamics of engineered bacteria. As a proof of principle, we demonstrated a safeguard strategy to prevent unintended bacterial proliferation. In particular, we adopted several synthetic gene circuits to program collective survival in Escherichia coli: the engineered bacteria could only survive when present at sufficiently high population densities. When encapsulated by permeable membranes, these bacteria can sense the local environment and respond accordingly. The cells inside the microbial swarmbot capsules will survive due to their high densities. Those escaping from a capsule, however, will be killed due to a decrease in their densities. We demonstrate that this design concept is modular and readily generalizable. Our work lays the foundation for engineering integrated and programmable control of hybrid biological-material systems for diverse applications. PMID:26925805

  15. Optically controlled photonic bandgap structures for microstrip circuits

    CERN Document Server

    Cadman, D A

    2003-01-01

    This thesis is concerned with the optical control of microwave photonic bandgap circuits using high resistivity silicon. Photoconducting processes that occur within silicon are investigated. The influence of excess carrier density on carrier mobility and lifetime is examined. In addition, electron-hole pair recombination mechanisms (Shockley-Read-Hall, Auger, radiative and surface) are investigated. The microwave properties of silicon are examined, in particular the variation of silicon reflectivity with excess carrier density. Filtering properties of microstrip photonic bandgap structures and how they may be controlled optically are studied. A proof-of-concept microstrip photonic bandgap structure with optical control is designed, simulated and measured. With no optical illumination incident upon the silicon, the microstrip photonic bandgap structure's filtering properties are well-defined; a 3dB stopband width of 2.6GHz, a 6dB bandwidth of 2GHz and stopband depth of -11.6dB at the centre frequency of 9.9GHz...

  16. Optically controlled photonic bandgap structures for microstrip circuits

    International Nuclear Information System (INIS)

    This thesis is concerned with the optical control of microwave photonic bandgap circuits using high resistivity silicon. Photoconducting processes that occur within silicon are investigated. The influence of excess carrier density on carrier mobility and lifetime is examined. In addition, electron-hole pair recombination mechanisms (Shockley-Read-Hall, Auger, radiative and surface) are investigated. The microwave properties of silicon are examined, in particular the variation of silicon reflectivity with excess carrier density. Filtering properties of microstrip photonic bandgap structures and how they may be controlled optically are studied. A proof-of-concept microstrip photonic bandgap structure with optical control is designed, simulated and measured. With no optical illumination incident upon the silicon, the microstrip photonic bandgap structure's filtering properties are well-defined; a 3dB stopband width of 2.6GHz, a 6dB bandwidth of 2GHz and stopband depth of -11.6dB at the centre frequency of 9.9GHz. When the silicon is illuminated, the structure's filtering properties are suppressed. Under illumination the experimental results display an increase in S21 of 6.5dB and a reduction in S11 of more than 10dB at 9.9GHz. A comparison of measured and simulated results reveal that the photogenerated excess carrier density is between 4 x 1015 cm-3 and 1.1 x 1016 cm-3. (author)

  17. Active quenching circuit for a InGaAs single-photon avalanche diode

    International Nuclear Information System (INIS)

    We present a novel gated operation active quenching circuit (AQC). In order to simulate the quenching circuit a complete SPICE model of a InGaAs SPAD is set up according to the I–V characteristic measurement results of the detector. The circuit integrated with aROIC (readout integrated circuit) is fabricated in an CSMC 0.5 μm CMOS process and then hybrid packed with the detector. Chip measurement results show that the functionality of the circuit is correct and the performance is suitable for practical system applications. (semiconductor integrated circuits)

  18. A low-delay digital PWM control circuit for DC-DC converters

    OpenAIRE

    Ishizuka, Yoichi; Ueno, Masao; Nishikawa, Ichiro; Ichinose, Akira; Matsuo, Hirofumi

    2007-01-01

    This paper is descried about a proposed scheme of a low-cost digital pulse width modulation (DPWM) control circuit for non-isolated DC-DC converter without A/D converter. Also,real-time PID control technique for DPWM is described. Some experimental results are revealed the proposed circuit and scheme. The purpose of this research is striking a balance between minimizing cost increase by digitalizing of the control circuit of DC-DC converter and speeding up the control circuit.

  19. Comprehensive figures of merit for passive and active plasmonic circuits

    CERN Document Server

    Krasavin, Alexey V

    2015-01-01

    In this article a comprehensive figures of merit for both passive and active plasmonic circuit components are introduced, benchmarking their performance for the realisation of high-bandwidth optical data communication in electronic chips. For the first time the figure of merit for passive plasmonic interconnects has been derived in terms of ultimate global characteristics of the plasmonic circuitry, particularly bandwidth and power consumption densities. Then, these parameters were linked to the local waveguide characteristics, such as mode propagation length, bending radius, etc. The figure has been applied to provide a comprehensive comparison to the main types of the plasmonics waveguides and can serve as an excellent benchmark for future designs. Completing the development of broadband optical on-chip data communication, we developed an all-inclusive figure of merit for active photonic- or plasmonic-based electro-optic modulators, establishing the communication between electronic and photonic chip domains...

  20. Optimization of linear parametric circuits by the control of stability

    Directory of Open Access Journals (Sweden)

    Yu. I. Shapovalov

    2013-07-01

    Full Text Available Introduction. A brief description of the symbolic frequency method for linear parametric circuit analysis is adduced. In particular it comes to parametric transfer functions and assessment of asymptotic stability of such circuits. The formulation of optimization task. The objective function formation is done via two functions - the function of goal defined by desirable circuit characteristics (goal of optimization and function characteristics of circuit defined by the selected values of the varied parameters during optimization of electrical circuit characteristics. The coincidence degree of these two functions is objective function which is formed on their basis by the chosen method. The procedure of optimization. The solution of optimization task is determining the values с0* and m* that provide minimum value of objective function, satisfy the condition of circuit stability and conditions of physical parametric element realizability Example. There is example of single-circuit parametric amplifier optimization using the objective function based on the calculation of parametric circuit transfer function with a symbolic representation of the parametric capacity parameters. Conclusions. Frequency symbolic analysis method allows solving optimization task of parametric linear circuits designing in the frequency domain based on use of the frequency symbolic transfer functions which are approximated by trigonometric polynomials of Fourier, particularly in complex form.

  1. Performance Evaluation a Developed Energy Harvesting Interface Circuit in Active Technique

    OpenAIRE

    Ramizi Mohamed; Mahidur R. Sarker; Azah Mohamed

    2014-01-01

    This study presents the performance evaluation a developed energy harvesting interface circuit in active technique. The energy harvesting interface circuit for micro-power applications uses equivalent voltage of the piezoelectric materials have been developed and simulated. Circuit designs and simulation results are presented for a conventional diode rectifier with voltage doubler in passive technique. Most of the existing techniques are mainly passive-based energy harvesting circuits. Genera...

  2. Dynorphin Controls the Gain of an Amygdalar Anxiety Circuit

    Directory of Open Access Journals (Sweden)

    Nicole A. Crowley

    2016-03-01

    Full Text Available Kappa opioid receptors (KORs are involved in a variety of aversive behavioral states, including anxiety. To date, a circuit-based mechanism for KOR-driven anxiety has not been described. Here, we show that activation of KORs inhibits glutamate release from basolateral amygdala (BLA inputs to the bed nucleus of the stria terminalis (BNST and occludes the anxiolytic phenotype seen with optogenetic activation of BLA-BNST projections. In addition, deletion of KORs from amygdala neurons results in an anxiolytic phenotype. Furthermore, we identify a frequency-dependent, optically evoked local dynorphin-induced heterosynaptic plasticity of glutamate inputs in the BNST. We also find that there is cell type specificity to the KOR modulation of the BLA-BNST input with greater KOR-mediated inhibition of BLA dynorphin-expressing neurons. Collectively, these results provide support for a model in which local dynorphin release can inhibit an anxiolytic pathway, providing a discrete therapeutic target for the treatment of anxiety disorders.

  3. Dynorphin Controls the Gain of an Amygdalar Anxiety Circuit.

    Science.gov (United States)

    Crowley, Nicole A; Bloodgood, Daniel W; Hardaway, J Andrew; Kendra, Alexis M; McCall, Jordan G; Al-Hasani, Ream; McCall, Nora M; Yu, Waylin; Schools, Zachary L; Krashes, Michael J; Lowell, Bradford B; Whistler, Jennifer L; Bruchas, Michael R; Kash, Thomas L

    2016-03-29

    Kappa opioid receptors (KORs) are involved in a variety of aversive behavioral states, including anxiety. To date, a circuit-based mechanism for KOR-driven anxiety has not been described. Here, we show that activation of KORs inhibits glutamate release from basolateral amygdala (BLA) inputs to the bed nucleus of the stria terminalis (BNST) and occludes the anxiolytic phenotype seen with optogenetic activation of BLA-BNST projections. In addition, deletion of KORs from amygdala neurons results in an anxiolytic phenotype. Furthermore, we identify a frequency-dependent, optically evoked local dynorphin-induced heterosynaptic plasticity of glutamate inputs in the BNST. We also find that there is cell type specificity to the KOR modulation of the BLA-BNST input with greater KOR-mediated inhibition of BLA dynorphin-expressing neurons. Collectively, these results provide support for a model in which local dynorphin release can inhibit an anxiolytic pathway, providing a discrete therapeutic target for the treatment of anxiety disorders. PMID:26997280

  4. Chaotic memristive circuit: equivalent circuit realization and dynamical analysis

    Institute of Scientific and Technical Information of China (English)

    Bao Bo-Cheng; Xu Jian-Ping; Zhou Guo-Hua; Ma Zheng-Hua; Zou Ling

    2011-01-01

    In this paper,a practical equivalent circuit of an active flux-controlled memristor characterized by smooth piecewise-quadratic nonlinearity is designed and an experimental chaotic memristive circuit is implemented.The chaotic memristive circuit has an equilibrium set and its stability is dependent on the initial state of the memristor.The initial state-dependent and the circuit parameter-dependent dynamics of the chaotic memristive circuit are investigated via phase portraits,bifurcation diagrams and Lyapunov exponents.Both experimental and simulation results validate the proposed equivalent circuit realization of the active flux-controlled memristor.

  5. 49 CFR 236.7 - Circuit controller operated by switch-and-lock movement.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit controller operated by switch-and-lock movement. 236.7 Section 236.7 Transportation Other Regulations Relating to Transportation (Continued... switch-and-lock movement. Circuit controller operated by switch-and-lock movement shall be maintained...

  6. Soft switching DC/DC converter using controlled output rectifier with auxiliary circuit

    OpenAIRE

    Dudrik, Jaroslav; BODOR Marcel; TRIP Daniel Nistor

    2010-01-01

    Auxiliary circuit for DC/DC converter withcontrolled output rectifier is presented in this paper.Soft switching for power switches of the inverter isachieved by using controlled output rectifier and softswitching of the controlled rectifier by using losslessauxiliary circuit. The principle of converter operationis explained and analyzed and experimental results onthe laboratory model are presented.

  7. Detection circuit of solenoid valve operation and control rod drive mechanism utilizing the circuit

    International Nuclear Information System (INIS)

    Object: To detect the operation of a plunger and detect opening and closing operations of a solenoid valve driving device due to change in impedance of a coil for driving the solenoid valve to judge normality and abnormality of the solenoid valve, thereby increasing reliance and safety of drive and control apparatus of control rods. Structure: An arrangement comprises a drive and operation detector section wherein the operation of a solenoid driving device for controlling power supply to a coil for driving the solenoid valve to control opening and closing of the solenoid valve, and a plunger operation detector section for detecting change in impedance of the drive coil to detect that the plunger of the solenoid valve is either in the opening direction or closing direction, whereby a predetermined low voltage such as not to activate the solenoid valve even when the solenoid valve is open or closed is applied to detect a current flowing into the coil at that time, thus detecting an operating state of the plunger. (Yoshino, Y.)

  8. Timing control circuit for real-time control of events in Aditya Tokamak

    International Nuclear Information System (INIS)

    Tokamak plasma is prone to many random events having potential for causing severe damages to the machine, such as disruptions, production and elimination of high-energy runaway electrons etc. These events can be mitigated by obtaining pre-cursor signal leading to these events and then taking proper measures just before their onset to avoid their happenings, like disruptions can be mitigated by massive gas injection or putting a bias voltage on an electrode placed inside the plasma, the runaways can be mitigated by gas injection and by applying specific magnetic fields. Hence for real time control of these events, the pre-cursors should be electronically recorded and the mitigation techniques should be initiated by sending triggers to their individual operational systems. To implement these methodologies of real-time controlling of events in Aditya Tokamak, a low cost multi-channel Micro-Controller based timing circuit is designed and developed in-house. This circuit first compares the precursor signals fed into it with the pre-set values and gives a trigger output whenever the signals overshoot the pre-set values. The circuit readies itself for operation along with start of the tokamak discharge and waits up to an initial pre-determined delay and then initiates a trigger at the time of overshooting of precursor signal. The circuit is fully integrated and assembled in compact enclosure with local LCD for threshold and initial trigger-delay monitoring and indicators for full stand-alone operation. The system has been successfully tested in the disruption control by biasing electrode experiments in Aditya tokamak. The MHD oscillations, precursor in this case, is monitored by this circuit and whenever the amplitude of these oscillations overshoot a particular pre-set value, a trigger is generated and delivered to a SCR switch which triggers the voltage on the electrode placed inside the plasma to avoid disruptions. The detailed design features and results will be

  9. Morphology controlled open circuit voltage in polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Chetan R.; Himmerlich, Marcel; Krischok, Stefan; Hoppe, Harald [Institute of Physics and Institute of Micro- and Nanotechnologies, Ilmenau University of Technology, 98684 Ilmenau (Germany); Sommer, Michael; Wicklein, Andre; Thelakkat, Mukundan [Applied Functional Polymers, University of Bayreuth, 95440 Bayreuth (Germany)

    2011-07-15

    We report a strong dependence of open circuit voltage on the altered morphology of block copolymer (P3HT-b -PPerAcr) based solar cells. The open circuit voltage increases dramatically by about 300 mV by increasing the amount of acceptor homopolymer within the block copolymer/homopolymer blends. The change in open circuit voltage is found to be in correlation with the enrichment of acceptor moiety at the film surface as identified by Atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Based on this fact, an additional increase in open circuit voltage to its maximum values is achieved by introducing an acceptor buffer layer at the cathode interface. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Performance Evaluation a Developed Energy Harvesting Interface Circuit in Active Technique

    Directory of Open Access Journals (Sweden)

    Ramizi Mohamed

    2014-10-01

    Full Text Available This study presents the performance evaluation a developed energy harvesting interface circuit in active technique. The energy harvesting interface circuit for micro-power applications uses equivalent voltage of the piezoelectric materials have been developed and simulated. Circuit designs and simulation results are presented for a conventional diode rectifier with voltage doubler in passive technique. Most of the existing techniques are mainly passive-based energy harvesting circuits. Generally, the power harvesting capability of the passive technique is very low. To increase the harvested energy, the active technique and its components such as MOSFET, thyristor and transistor have chosen to design the proposed energy harvesting interface circuit. In this study, it has simulated both the conventional in passive circuit and developed energy harvester in active technique. The developed interface circuits consisting of piezoelectric element with input source of vibration, AC-DC thyristor doubler rectifier circuit and DC-DC boost converter using thyristor with storage device. In the development circuits, it is noted that the components thyristor instead of mainly diode available in conventional circuits have chosen. Because the forward voltage potential (0.7 V is higher than the incoming input voltage (0.2 V. Finally, the complete energy harvester using PSPICE software have designed and simulated. The proposed circuits in PSPICE generate the boost-up DC voltage up to 2 V. The overall efficiency of the developed circuit is 70%, followed by the software simulation, which is greater than conventional circuit efficiency of 20% in performance evaluator. It is concluded that the developed circuit output voltage can be used to operate for the applications in autonomous devices.

  11. Multiswitching Synchronization of a Driven Hyperchaotic Circuit Using Active Backstepping

    Directory of Open Access Journals (Sweden)

    A. Ayotunde Ajayi

    2014-01-01

    Full Text Available An active backstepping technique is proposed for the realization of multiswitching synchronization of periodically forced hyperchaotic Van der Pol-Duffing oscillators. The active backstepping technique is a systematic design approach with recursive procedures that skillfully optimizes the choice of Lyapunov functions and active control technique. Using the active backstepping technique, the usual master-slave synchronization scheme is extended to study the synchronization of systems with different combinations of the slave states variables with master state variables. Our numerical results confirm the effectiveness of the proposed analytical technique.

  12. The Signal Detection and Control Circuit Design for Confocal Auto-Focus System

    Directory of Open Access Journals (Sweden)

    Yin Liu

    2016-01-01

    Full Text Available Based on the demands of Confocal Auto-Focus system, the implementation method of signal measurement circuit and control circuit is given. Using the high performance instrumental amplifier AD620BN, low noise precision FET Op amplifier AD795JRZ and ultralow offset voltage Op amplifier OP07EP, a signal measurement circuit used to converse the two differential light intensity signal to electric signal is designed. And a control circuit which takes MCU MSP430F149 as core processes the former signal and generate a control signal driving the platform for auto-focusing. The experimental results proved the feasibility and correctness of circuits. And the system meets the design requirement.

  13. Decoding the organization of spinal circuits that control locomotion

    OpenAIRE

    Kiehn, Ole

    2016-01-01

    Unravelling the functional operation of neuronal networks and linking cellular activity to specific behavioural outcomes are among the biggest challenges in neuroscience. In this broad field of research, substantial progress has been made in studies of the spinal networks that control locomotion. Through united efforts using electrophysiological and molecular genetic network approaches and behavioural studies in phylogenetically diverse experimental models, the organization of locomotor netwo...

  14. Sensitivity analysis of an LCL-filter-based three-phase active rectifier via a virtual circuit approach

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Chiarantoni, Ernesto; Aquila, Antonio Dell’; Liserre, Marco; Vergura, Silvano

    2004-01-01

    Three-phase active rectifiers based on the voltage source converter topology can successfully replace traditional thyristor based rectifiers or diode bridge plus chopper in interfacing dc-systems to the grid. However, if the application in which they are employed has a high safety issue or if there......, to the grid side stiffness and to the parameters of the controller has never been detailed considered. In this paper the experimental results of an LCL-filter-based three-phase active rectifier are analysed with the circuit theory approach. A ?virtual circuit? is synthesized in role of the digital...

  15. Advanced active quenching circuits for single-photon avalanche photodiodes

    Science.gov (United States)

    Stipčević, M.; Christensen, B. G.; Kwiat, P. G.; Gauthier, D. J.

    2016-05-01

    Commercial photon-counting modules, often based on actively quenched solid-state avalanche photodiode sensors, are used in wide variety of applications. Manufacturers characterize their detectors by specifying a small set of parameters, such as detection efficiency, dead time, dark counts rate, afterpulsing probability and single photon arrival time resolution (jitter), however they usually do not specify the conditions under which these parameters are constant or present a sufficient description. In this work, we present an in-depth analysis of the active quenching process and identify intrinsic limitations and engineering challenges. Based on that, we investigate the range of validity of the typical parameters used by two commercial detectors. We identify an additional set of imperfections that must be specified in order to sufficiently characterize the behavior of single-photon counting detectors in realistic applications. The additional imperfections include rate-dependence of the dead time, jitter, detection delay shift, and "twilighting." Also, the temporal distribution of afterpulsing and various artifacts of the electronics are important. We find that these additional non-ideal behaviors can lead to unexpected effects or strong deterioration of the system's performance. Specifically, we discuss implications of these new findings in a few applications in which single-photon detectors play a major role: the security of a quantum cryptographic protocol, the quality of single-photon-based random number generators and a few other applications. Finally, we describe an example of an optimized avalanche quenching circuit for a high-rate quantum key distribution system based on time-bin entangled photons.

  16. Dynamic control of a central pattern generator circuit: a computational model of the snail feeding network.

    Science.gov (United States)

    Vavoulis, Dimitris V; Straub, Volko A; Kemenes, Ildikó; Kemenes, György; Feng, Jianfeng; Benjamin, Paul R

    2007-05-01

    Central pattern generators (CPGs) are networks underlying rhythmic motor behaviours and they are dynamically regulated by neuronal elements that are extrinsic or intrinsic to the rhythmogenic circuit. In the feeding system of the pond snail, Lymnaea stagnalis, the extrinsic slow oscillator (SO) interneuron controls the frequency of the feeding rhythm and the N3t (tonic) has a dual role; it is an intrinsic CPG interneuron, but it also suppresses CPG activity in the absence of food, acting as a decision-making element in the feeding circuit. The firing patterns of the SO and N3t neurons and their synaptic connections with the rest of the CPG are known, but how these regulate network function is not well understood. This was investigated by building a computer model of the feeding network based on a minimum number of cells (N1M, N2v and N3t) required to generate the three-phase motor rhythm together with the SO that was used to activate the system. The intrinsic properties of individual neurons were represented using two-compartment models containing currents of the Hodgkin-Huxley type. Manipulations of neuronal activity in the N3t and SO neurons in the model produced similar quantitative effects to food and electrical stimulation in the biological network indicating that the model is a useful tool for studying the dynamic properties of the feeding circuit. The model also predicted novel effects of electrical stimulation of two CPG interneurons (N1M and N2v). When tested experimentally, similar effects were found in the biological system providing further validation of our model. PMID:17561845

  17. Exposure to Forced Swim Stress Alters Local Circuit Activity and Plasticity in the Dentate Gyrus of the Hippocampus

    Directory of Open Access Journals (Sweden)

    Orli Yarom

    2008-01-01

    Full Text Available Studies have shown that, depending on its severity and context, stress can affect neural plasticity. Most related studies focused on synaptic plasticity and long-term potentiation (LTP of principle cells. However, evidence suggests that following high-frequency stimulation, which induces LTP in principal cells, modifications also take place at the level of complex interactions with interneurons within the dentate gyrus, that is, at the local circuit level. So far, the possible effects of stress on local circuit activity and plasticity were not studied. Therefore, we set out to examine the possible alterations in local circuit activity and plasticity following exposure to stress. Local circuit activity and plasticity were measured by using frequency dependant inhibition (FDI and commissural modulation protocols following exposure to a 15 minute-forced swim trial. Exposure to stress did not alter FDI. The application of theta-burst stimulation (TBS reduced FDI in both control and stressed rats, but this type of plasticity was greater in stressed rats. Commissural-induced inhibition was significantly higher in stressed rats both before and after applying theta-burst stimulation. These findings indicate that the exposure to acute stress affects aspects of local circuit activity and plasticity in the dentate gyrus. It is possible that these alterations underlie some of the behavioral consequences of the stress experience.

  18. Microcontroller based phase control circuit for resonant power converters

    OpenAIRE

    Milcevski, Dejan; Stefanov, Goce; Karadzinov, Ljupco

    2011-01-01

    A microcontroller based circuit is developed for driving the IGBT switches of a bridge resonant power converter used for induction heating of metals. When a resonant power converter is used for induction heating the load is variable due to the effects of the heating process making the converter to operate out of resonance. This effect decreases the converter output power and increases switching loses. In order to maintain constant output power operating constantly on the resonant frequency a ...

  19. Supermode control in integrated hybrid Si/III–V optoelectronic circuits for modal gain enhancement

    OpenAIRE

    Sun, Xiankai; Yariv, Amnon

    2009-01-01

    We propose using supermode control to enhance the modal gain in integrated hybrid Si/III–V optoelectronic circuits. Numerical simulations predict that a 4-fold enhancement in modal gain can be achieved with optimal design.

  20. A Time-Delay Suppression Technique for Digital PWM Control Circuit

    OpenAIRE

    Ishizuka, Yoichi

    2010-01-01

    This paper describes a digital PWM controller IC without A/D converters. The analog timing converter (ATC) is proposed for output voltage sensing. In this system, analog circuit are realized with an comparator and an D/A converter.

  1. Designing signal conditioning circuit for stability control system of LINAC modulator

    International Nuclear Information System (INIS)

    Background: Shanghai Soft X-ray FEL is under design and construction at Shanghai Institute of Applied Physics (SINAP). Purpose: The stability of the existing SSRF Linac modulator has achieved 500 ppm. But the Soft X-FEL requires 100 PPM. Methods: This paper describes control strategy based on pulse amplitude feedback technology, and gives the design of signal conditioning circuit in more details. The signal conditioning circuit contains amplitude fading, LPF and cutting etc. Results: The relevant experiments show that the circuit reaches required function and stability. Conclusions: Feedback control strategy is useful for the existing modulator. (authors)

  2. Improved AC pixel electrode circuit for active matrix of organic light-emitting display

    Science.gov (United States)

    Si, Yujuan; Lang, Liuqi; Chen, Wanzhong; Liu, Shiyong

    2004-05-01

    In this paper, a modified four-transistor pixel circuit for active-matrix organic light-emitting displays (AMOLED) was developed to improve the performance of OLED device. This modified pixel circuit can provide an AC driving mode to make the OLED working in a reversed-biased voltage during the certain cycle. The optimized values of the reversed-biased voltage and the characteristics of the pixel circuit were investigated using AIM-SPICE. The simulated results reveal that this circuit can provide a suitable output current and voltage characteristic, and little change was made in luminance current.

  3. Local Circuit Inhibition in the Cerebral Cortex as the source of Gain Control and Untuned Suppression

    OpenAIRE

    Shapley, Robert M.; Xing, Dajun

    2012-01-01

    Theoretical considerations have led to the concept that the cerebral cortex is operating in a balanced state in which synaptic excitation is approximately balanced by synaptic inhibition from the local cortical circuit. This paper is about the functional consequences of the balanced state in sensory cortex. One consequence is gain control: there is experimental evidence and theoretical support for the idea that local circuit inhibition acts as a local automatic gain control throughout the cor...

  4. Simulation of electrical machines, circuits and control systems using finite element method and system simulator

    OpenAIRE

    Kanerva, Sami

    2005-01-01

    The aim of this study is to provide a combined simulation environment capable of modelling and analyzing the interaction between electrical machines and controlled converters. For that purpose, two indirect methods are presented for coupling the magnetic field computation of electrical machines with the simulation of circuits and control systems. The methods are implemented for the system simulator SIMULINK as functional blocks, which solve the field and circuit equations relating to the elec...

  5. Utility design of electronic circuit

    International Nuclear Information System (INIS)

    This is comprised of eleven chapters about electronic circuit design and utility circuit for electronics, which includes the point of design on electronic circuit like logical circuit, sensor circuit and power circuit, acoustic system, image system, communication system like FSK demodulation circuit, measurement and control system, appliance, operating amplifier, conversion device, counter and timer, sensor circuit, motor control such as DC motor control circuit and stepping motor drive circuit and power device like electric current control circuit.

  6. Design of Microcantilever-Based Biosensor with Digital Feedback Control Circuit

    Directory of Open Access Journals (Sweden)

    Jayu P. Kalambe

    2012-01-01

    Full Text Available This paper present the design of cantilever-based biosensors with new readout, which hold promises as fast and cheap “point of care” device as well as interesting research tools. The fabrication process and related issues of the cantilever based bio-sensor are discussed. Coventorware simulation is carried out to analyze the device behavior. A fully integrated control circuit has been designed to solve manufacturing challenge which will take care of positioning of the cantilever instead of creating nanometer gap between the electrodes. The control circuit will solve the manufacturing challenge faced by the readout methods where it is essential to maintain precise gap between the electrodes. The circuit can take care of variation obtained due to fabrication process and maintain the precise gap between the electrodes by electrostatic actuation. The control circuit consist of analog and digital modules. The reliability issues of the sensor are also discussed.

  7. Impaired activity-dependent neural circuit assembly and refinement in autism spectrum disorder genetic models

    OpenAIRE

    Caleb Andrew Doll; Kendal eBroadie

    2014-01-01

    Early-use activity during circuit-specific critical periods refines brain circuitry by the coupled processes of eliminating inappropriate synapses and strengthening maintained synapses. We theorize these activity-dependent developmental processes are specifically impaired in autism spectrum disorders (ASDs). ASD genetic models in both mouse and Drosophila have pioneered our insights into normal activity-dependent neural circuit assembly and consolidation, and how these developmental mechanism...

  8. Analysis of Electrical Circuits with Controlled Sources through the Principle of Superposition

    Directory of Open Access Journals (Sweden)

    T. S. Rathore

    2012-07-01

    Full Text Available In the text books, while solving the circuits with controlled sources using Principle of superposition (POS, controlled sources are not deactivated. Thus POS has not been applied in the ‘true sense’ to circuits with dependent sources. It is shown here that POS can be applied in the ‘true sense’ to such circuits also, but with caution. POS is applicable to all those circuits with dependent sources as well, if it is applicable to these circuits when all the dependent sources are treated as independent sources. We have included two such examples: one which cannot be solved only employing series-parallel reduction, current voltage division, and Ohm’s law, second which has more than one controlled sources. The method based on POS is compared with that based on Miller equivalents and generalized matrix method. It is shown that the latter one is the most efficient. It is hoped that the teachers will emphasize that POS can be applied, in the true sense, for analysing circuits with controlled sources. The prospective authors would include this theory in their future text books. However, they should motivate the students to use generalized matrix method for better efficiency.

  9. A High Step-Down Interleaved Buck Converter with Active-Clamp Circuits for Wind Turbines

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2012-12-01

    Full Text Available In this paper, a high step-down interleaved buck coupled-inductor converter (IBCC with active-clamp circuits for wind energy conversion has been studied. In high step-down voltage applications, an IBCC can extend duty ratio and reduce voltage stresses on active switches. In order to reduce switching losses of active switches to improve conversion efficiency, a IBCC with soft-switching techniques is usually required. Compared with passive-clamp circuits, the IBCC with active-clamp circuits have lower switching losses and minimum ringing voltage of the active switches. Thus, the proposed IBCC with active-clamp circuits for wind energy conversion can significantly increase conversion efficiency. Finally, a 240 W prototype of the proposed IBCC with active-clamp circuits was built and implemented. Experimental results have shown that efficiency can reach as high as 91%. The proposed IBCC with active-clamp circuits is presented in high step-down voltage applications to verify the performance and the feasibility for energy conversion of wind turbines.

  10. A Circuit for Motor Cortical Modulation of Auditory Cortical Activity

    OpenAIRE

    Nelson, Anders; Schneider, David M.; Takatoh, Jun; Sakurai, Katsuyasu; Wang, Fan; Mooney, Richard

    2013-01-01

    Normal hearing depends on the ability to distinguish self-generated sounds from other sounds, and this ability is thought to involve neural circuits that convey copies of motor command signals to various levels of the auditory system. Although such interactions at the cortical level are believed to facilitate auditory comprehension during movements and drive auditory hallucinations in pathological states, the synaptic organization and function of circuitry linking the motor and auditory corti...

  11. Passive and active elements using fractional Lβ C α circuit

    KAUST Repository

    Radwan, Ahmed Gomaa

    2011-10-01

    This paper introduces a qualitative revision of the traditional LC tank circuit in the fractional domain. The paper can be divided into six major parts, aiming in turn to establish the various conditions under which L βCα impedance may act as a resistor, negative resistor, or a positive or negative pure imaginary inductor or capacitor, in accordance to new frequency definitions; illustrate the process by which the phase response chooses the shortest path from initial to final phase, and use this illustration to verify the cases discussed in part one; develop the generalized parameters for the bandpass filter response of the L βCα circuit, such as the resonance frequency and quality factor versus α-β plane; discuss sensitivity analyses with respect to the fractional orders, as well as the time domain analyses for the impulse and step responses with their analytical formulas; and lastly, to propose some possible applications for this generalized circuit. Mathematical and PSpice simulation results are included to validate the discussion. © 2011 IEEE.

  12. 78 FR 37203 - Authorization of Production Activity; Subzone 196A; TTI, Inc. (Electromechanical and Circuit...

    Science.gov (United States)

    2013-06-20

    ... comment (78 FR 15683, 03-12-2013). The FTZ Board has determined that no further review of the activity is... and Circuit Protection Devices Production/Kitting); Fort Worth, Texas On February 13, 2013, TTI,...

  13. Feasibility of Tunable Amplifier and Bandpass Filter for Mobile Handsets Using Active Inductor Circuits

    OpenAIRE

    Majeed, B.; N. T. Ali; J. Rodriguez Tellez

    2002-01-01

    In this paper active inductor circuits are employed to assess their suitability for providing a tuning function in GaAs MMIC circuits. The specifications for a mobile handset amplifier and a bandpass filter operating from a 3 V supply rail are used as test vehicles. The design and simulation of the circuits employs a low-cost commercially available low pinch-off GaAs MESFET process. The suitability of active inductors for tuning in such applications considers issues such as frequency tuning r...

  14. Design of a semi-custom integrated circuit for the SLAC SLC timing control system

    International Nuclear Information System (INIS)

    A semi-custom (gate array) integrated circuit has been designed for use in the SLAC Linear Collider timing and control system. The design process and SLAC's experiences during the phases of the design cycle are described. Issues concerning the partitioning of the design into semi-custom and standard components are discussed. Functional descriptions of the semi-custom integrated circuit and the timing module in which it is used are given

  15. Thermoelectric devices and diamond films for temperature control of high density electronic circuits

    International Nuclear Information System (INIS)

    The increased speeds of integrated circuits is accompanied by increased power levels and the need to package the IC chips very close together. Combined, these spell very high power densities and severe thermal problems at the package level. Conventional packaging materials have difficulty dealing with these thermal management problems. However, it is possible to combine both active and passive cooling by using thin film bismuth-telluride thermoelectric coolers (microcoolers) and diamond substrates for the temperature control of these high density electronic circuits. The highest power components would be mounted directly onto thin film thermoelectric elements, which would maintain the temperature of these components from a few degrees to tens of degrees below that of the diamond substrate. This allows these components to operate within their required temperature range, effectively manage temperature spikes and junction temperatures, and increase clockspeed. To optimize the design of the thermoelectric cooler and operate at maximum efficiency, diamond films acting as thermal lenses would also be used to spread the heat from the small power device to the larger coolers. In those instances where the devices are all operating above ambient temperature, high thermal conductivity diamond films alone are sufficient to cool these devices, by effectively conducting the heat throughout the board. copyright 1995 American Institute of Physics

  16. Integrated Brain Circuits: Astrocytic Networks Modulate Neuronal Activity and Behavior

    Science.gov (United States)

    Halassa, Michael M.; Haydon, Philip G.

    2011-01-01

    The past decade has seen an explosion of research on roles of neuron-astrocyte interactions in the control of brain function. We highlight recent studies performed on the tripartite synapse, the structure consisting of pre- and postsynaptic elements of the synapse and an associated astrocytic process. Astrocytes respond to neuronal activity and neuro-transmitters, through the activation of metabotropic receptors, and can release the gliotransmitters ATP, D-serine, and glutamate, which act on neurons. Astrocyte-derived ATP modulates synaptic transmission, either directly or through its metabolic product adenosine. D-serine modulates NMDA receptor function, whereas glia-derived glutamate can play important roles in relapse following withdrawal from drugs of abuse. Cell type–specific molecular genetics has allowed a new level of examination of the function of astrocytes in brain function and has revealed an important role of these glial cells that is mediated by adenosine accumulation in the control of sleep and in cognitive impairments that follow sleep deprivation. PMID:20148679

  17. Sub-Kelvin single flux quantum control circuits and multi-chip packaging for supporting superconducting qubit

    International Nuclear Information System (INIS)

    Superconducting single flux quantum (SFQ) circuit can operate at very low temperature. This is suitable for controlling a quantum computing system with Josephson junctions. However, it is difficult to integrate both SFQ circuits and qubits into a single-chip, because of the dissipative characteristics of SFQ circuits. Therefore, we have developed a multi-chip packaging technology for a qubit control module. The module consists of SFQ circuit chips, qubit chips, and a substrate all of which are fabricated with Nb and Al technology. The chips are flip-chip bonded with superconducting solder bumps. We also investigated SFQ control circuits for superconducting qubits and circuit parameter optimization for sub-Kelvin temperature operation. Using both multi-chip packaging and optimized SFQ control circuit makes the design of qubit control module more flexible

  18. Four quadrant control circuit for a brushless three-phase dc motor

    Science.gov (United States)

    Nola, Frank J. (Inventor)

    1987-01-01

    A control circuit is provided for a brushless three-phase dc motor which affords four quadrant control from a single command. The control circuit probes acceleration of the motor in both clockwise and counterclockwise directions and braking and generation in both clockwise and counterclockwise directions. In addition to turning on individual transistors of the transistor pairs connected to the phase windings of the motor for 120 deg periods while the other transistor of that pair is off, the control circuit also provides, in a future mode of operation, turning the two transistors of each pair on and off alternately at a phase modulation frequency during such a 120 deg period. A feedback signal is derived which is proportional to the motor current and which has a polarity consistent with the command signal, such that negative feedback results.

  19. A logical molecular circuit for programmable and autonomous regulation of protein activity using DNA aptamer-protein interactions

    OpenAIRE

    Han, Da; Zhu, Zhi; Wu, Cuichen; Peng, Lu; Zhou, Leiji; Gulbakan, Basri; Zhu, Guizhi; Williams, Kathryn R.; Tan, Weihong

    2012-01-01

    Researchers increasingly envision an important role for artificial biochemical circuits in biological engineering, much like electrical circuits in electrical engineering. Similar to electrical circuits, which control electromechanical devices, biochemical circuits could be utilized as a type of servomechanism to control nanodevices in vitro, monitor chemical reactions in situ, or regulate gene expressions in vivo.1 As a consequence of their relative robustness and potential applicability for...

  20. Predictive maintenance of electrical components through computer-controlled acquisition and trending of standard circuit parameters

    International Nuclear Information System (INIS)

    Condition monitoring techniques are finding greater acceptance within many power plant maintenance organizations as plant operators develop predictive maintenance programs. This paper describes a proven condition monitoring technique and it's application in an electrical circuit predictive maintenance program. The technique performs a series of standard electrical measurements, under computer control, using a pre-defined test methodology. The test data is evaluated by utilizing statistical analysis methods and by comparisons through graphical representations. These methods allow comparisons with data from similar circuits or with baseline measurements. Circuit and component degradation appears as a change in one or more of the measured electrical parameters. Trending these parameters over time provides for early identification of circuit degradation. Incorporating this technique into a plant predictive maintenance program will switch maintenance personnel from a reactive to proactive position

  1. A circuit scheme to control current surge for RFID-NVM pumps

    Energy Technology Data Exchange (ETDEWEB)

    Li Ming; Kang Jinfeng; Wang Yangyuan [Institute of Microelectronics, Peking University, Beijing 100871 (China); Yang Liwu, E-mail: prettynecess@163.co [Semiconductor Manufacturing International Corporation, Shanghai 201203 (China)

    2010-02-15

    This paper presents a new circuit scheme to control the current surge in the boosting phase of an radio frequency idenfication-nonvolative memory pump. By introducing a circuit block consisting of a current reference and a current mirror, the new circuit scheme can keep the period-average current of the pump constantly below the desired level, for example, 2.5 {mu}A. Therefore, it can prevent the rectified supply of the RFID tag IC from collapsing in the boosting phase of the pump. The presented scheme could effectively reduce the voltage drop on the rectified supply from more than 50% to even zero, but could cost less area. Moreover, an analytical expression to calculate the boosting time of a pump in the new scheme is developed. (semiconductor integrated circuits)

  2. A circuit scheme to control current surge for RFID-NVM pumps

    International Nuclear Information System (INIS)

    This paper presents a new circuit scheme to control the current surge in the boosting phase of an radio frequency idenfication-nonvolative memory pump. By introducing a circuit block consisting of a current reference and a current mirror, the new circuit scheme can keep the period-average current of the pump constantly below the desired level, for example, 2.5 μA. Therefore, it can prevent the rectified supply of the RFID tag IC from collapsing in the boosting phase of the pump. The presented scheme could effectively reduce the voltage drop on the rectified supply from more than 50% to even zero, but could cost less area. Moreover, an analytical expression to calculate the boosting time of a pump in the new scheme is developed. (semiconductor integrated circuits)

  3. E-Learning System for Learning Virtual Circuit Making with a Microcontroller and Programming to Control a Robot

    Science.gov (United States)

    Takemura, Atsushi

    2015-01-01

    This paper proposes a novel e-Learning system for learning electronic circuit making and programming a microcontroller to control a robot. The proposed e-Learning system comprises a virtual-circuit-making function for the construction of circuits with a versatile, Arduino microcontroller and an educational system that can simulate behaviors of…

  4. Simulation of Aorta Artery Aneurysms Using Active Electronic Circuit

    Directory of Open Access Journals (Sweden)

    Kamran Hassani

    2007-01-01

    Full Text Available The fusiform and saccular aneurysms in different aorta artery sections were studied using an electronic circuit of cardiovascular system. The geometrical model of each artery section including thoracic and abdominal were generated in accordance with original anatomical data. By increasing the rate of aneurysm in each studied section, the pressure drop were calculated using CFD method, furthermore the compliance variations due to aneurysms were determined by mathematical method. The equivalent electronic circuit was then used to study the effects of the pressure drops and compliance variations on whole cardiovascular system. The results of the simulation exhibited the features of the pathology, including hypertension, the increase of the pulse pressure with the rate of aneurysm and the large magnitude of back flow during systole. Finally, the obtained results were compared with relevant clinical data .We have concluded from the study that aorta aneurysms in both fusiform and saccular, especially at highest diameters, may be the most important determinant of the artery rapture and heart failure.

  5. Designing an Electro-Hydraulic Control Module for an Open-Circuit Variable Displacement Pump

    DEFF Research Database (Denmark)

    Pedersen, Henrik Clemmensen; Andersen, Torben Ole; Hansen, Michael Rygaard

    2005-01-01

    This paper deals with the problem of designing an electric control module for a Sauer-Danfoss Series 45 H-frame open circuit axial piston pump. The purpose of the electric control module is to replace the existing hydro-mechanical (LS) regulator, and enable the pump to follow a reference pressure...

  6. Primary and secondary circuit pressure control at a nuclear power plant

    International Nuclear Information System (INIS)

    The guide contains design and analysis requirements for the primary and secondary circuit pressure control systems of nuclear power plants equipped with pressurized and boiling water reactors. For the purpose of this guide, pressure control means pressure regulation, overpressure protection and pressure reduction

  7. Incorporating Artificial Neural Networks in the dynamic thermal-hydraulic model of a controlled cryogenic circuit

    Science.gov (United States)

    Carli, S.; Bonifetto, R.; Savoldi, L.; Zanino, R.

    2015-09-01

    A model based on Artificial Neural Networks (ANNs) is developed for the heated line portion of a cryogenic circuit, where supercritical helium (SHe) flows and that also includes a cold circulator, valves, pipes/cryolines and heat exchangers between the main loop and a saturated liquid helium (LHe) bath. The heated line mimics the heat load coming from the superconducting magnets to their cryogenic cooling circuits during the operation of a tokamak fusion reactor. An ANN is trained, using the output from simulations of the circuit performed with the 4C thermal-hydraulic (TH) code, to reproduce the dynamic behavior of the heated line, including for the first time also scenarios where different types of controls act on the circuit. The ANN is then implemented in the 4C circuit model as a new component, which substitutes the original 4C heated line model. For different operational scenarios and control strategies, a good agreement is shown between the simplified ANN model results and the original 4C results, as well as with experimental data from the HELIOS facility confirming the suitability of this new approach which, extended to an entire magnet systems, can lead to real-time control of the cooling loops and fast assessment of control strategies for heat load smoothing to the cryoplant.

  8. A universal gyroscope driving circuit with 70dB amplitude control range

    KAUST Repository

    Abdelghany, Mohamed A.

    2010-08-01

    A CMOS variable gain driving circuit with output signal amplitude control for gyroscopes with wide range of quality factors is presented. The driving circuit can be used for gyroscopes with Q values higher than 500. The circuit uses a current-commutating switching mixer to control the gyroscope driving signal level. Conventional driving circuits use automatic gain control (AGC) which suffers from limited linear range and the need for an off-chip capacitor for the peak detector and loop filter. Two stage variable gain amplifier is used in the proposed design to ensure enough gain for oscillation for such a wide range of quality factors. Analog and digital amplitude control methods are used to cover wide range of driving signal amplitude with enough accuracy to hit the maximum driving signal level without sacrificing gyroscope linearity. Due to the high DC gain of the amplifier chain, DC offset resulting from mismatches might saturate the amplifier output. DC offset correction is employed using a secondary negative feedback loop. The proposed driving circuit is being fabricated in 0.6μm CMOS technology. © 2010 IEEE.

  9. Frequency-specific flow control in microfluidic circuits with passive elastomeric features

    Science.gov (United States)

    Leslie, Daniel C.; Easley, Christopher J.; Seker, Erkin; Karlinsey, James M.; Utz, Marcel; Begley, Matthew R.; Landers, James P.

    2009-03-01

    A fundamental challenge in the design of microfluidic devices lies in the need to control the transport of fluid according to complex patterns in space and time, and with sufficient accuracy. Although strategies based on externally actuated valves have enabled marked breakthroughs in chip-based analysis, this requires significant off-chip hardware, such as vacuum pumps and switching solenoids, which strongly tethers such devices to laboratory environments. Severing the microfluidic chip from this off-chip hardware would enable a new generation of devices that place the power of microfluidics in a broader range of disciplines. For example, complete on-chip flow control would empower highly portable microfluidic tools for diagnostics, forensics, environmental analysis and food safety, and be particularly useful in field settings where infrastructure is limited. Here, we demonstrate an elegantly simple strategy for flow control: fluidic networks with embedded deformable features are shown to transport fluid selectively in response to the frequency of a time-modulated pressure source. Distinct fluidic flow patterns are activated through the dynamic control of a single pressure input, akin to the analog responses of passive electrical circuits composed of resistors, capacitors and diodes.

  10. Developmental regulation of spatio-temporal patterns of cortical circuit activation

    OpenAIRE

    Trevor Charles Griffen; Arianna Maffei

    2013-01-01

    Neural circuits are refined in an experience-dependent manner during early postnatal development. How development modulates the spatio-temporal propagation of activity through cortical circuits is poorly understood. Here we use voltage sensitive dye imaging (VSD) to show that there are significant changes in the spatio-temporal patterns of intracortical signals in primary visual cortex from postnatal day 13 (P13), eye opening, to P28, the peak of the critical period for rodent visual cortical...

  11. Developmental regulation of spatio-temporal patterns of cortical circuit activation

    OpenAIRE

    Griffen, Trevor C.; Wang, Lang; Fontanini, Alfredo; Maffei, Arianna

    2013-01-01

    Neural circuits are refined in an experience-dependent manner during early postnatal development. How development modulates the spatio-temporal propagation of activity through cortical circuits is poorly understood. Here we use voltage-sensitive dye imaging (VSD) to show that there are significant changes in the spatio-temporal patterns of intracortical signals in primary visual cortex (V1) from postnatal day 13 (P13), eye opening, to P28, the peak of the critical period for rodent visual cor...

  12. Loss compensation in Metamaterials through embedding of active transistor based negative differential resistance circuits

    OpenAIRE

    Xu, Wangren; Padilla, Willie J.; Sonkusale, Sameer

    2012-01-01

    This paper presents an all-electronic approach for loss compensation in metamaterials. This is achieved by embedding active-transistors based negative differential resistance (NDR) circuits in each unit cell of the metamaterial lattice. NDR circuits provide tunable loss compensation over a broad frequency range limited only by the maximum operating frequency of transistors that is reaching terahertz values in newer semiconductor processes. Design, simulation and experimental results of metama...

  13. Active noise control for high frequencies

    OpenAIRE

    Kaymak, E; Atherton, MA; Rotter, KRG; Millar, B.

    2006-01-01

    There are many applications that can benefit from Active Noise Control (ANC) such as in aircraft cabins and air conditioning ducts, i.e. in situations where technology interferes with human hearing in a harmful way or disrupts communication. Headsets with analogue ANC circuits have been used in the armed forces for attenuating frequencies below 1 kHz, which when combined with passive filtering offers protection across the whole frequency range of human hearing. A dental surgery is also a nois...

  14. Synchronization of a modified Chua's circuit system via adaptive sliding mode control

    International Nuclear Information System (INIS)

    This study addresses the adaptive synchronization of a modified Chua's circuit system with both unknown system parameters and the nonlinearity in the control input. An adaptive switching surface is newly adopted such that it becomes easy to ensure the stability of the error dynamics in the sliding mode. Based on this adaptive switching surface, an adaptive sliding mode controller (ASMC) is derived to guarantee the occurrence of the sliding motion, even when the system is undergoing input nonlinearity. This method can also be easily extended to a general class of Chua's circuits. An illustrative example is given to show the applicability of the proposed ASMC design

  15. A resting state network in the motor control circuit of the basal ganglia

    Directory of Open Access Journals (Sweden)

    Bruzzone Lorenzo

    2009-11-01

    Full Text Available Abstract Background In the absence of overt stimuli, the brain shows correlated fluctuations in functionally related brain regions. Approximately ten largely independent resting state networks (RSNs showing this behaviour have been documented to date. Recent studies have reported the existence of an RSN in the basal ganglia - albeit inconsistently and without the means to interpret its function. Using two large study groups with different resting state conditions and MR protocols, the reproducibility of the network across subjects, behavioural conditions and acquisition parameters is assessed. Independent Component Analysis (ICA, combined with novel analyses of temporal features, is applied to establish the basis of signal fluctuations in the network and its relation to other RSNs. Reference to prior probabilistic diffusion tractography work is used to identify the basal ganglia circuit to which these fluctuations correspond. Results An RSN is identified in the basal ganglia and thalamus, comprising the pallidum, putamen, subthalamic nucleus and substantia nigra, with a projection also to the supplementary motor area. Participating nuclei and thalamo-cortical connection probabilities allow this network to be identified as the motor control circuit of the basal ganglia. The network was reproducibly identified across subjects, behavioural conditions (fixation, eyes closed, field strength and echo-planar imaging parameters. It shows a frequency peak at 0.025 ± 0.007 Hz and is most similar in spectral composition to the Default Mode (DM, a network of regions that is more active at rest than during task processing. Frequency features allow the network to be classified as an RSN rather than a physiological artefact. Fluctuations in this RSN are correlated with those in the task-positive fronto-parietal network and anticorrelated with those in the DM, whose hemodynamic response it anticipates. Conclusion Although the basal ganglia RSN has not been

  16. Developmental regulation of spatio-temporal patterns of cortical circuit activation

    Directory of Open Access Journals (Sweden)

    Trevor Charles Griffen

    2013-01-01

    Full Text Available Neural circuits are refined in an experience-dependent manner during early postnatal development. How development modulates the spatio-temporal propagation of activity through cortical circuits is poorly understood. Here we use voltage sensitive dye imaging (VSD to show that there are significant changes in the spatio-temporal patterns of intracortical signals in primary visual cortex from postnatal day 13 (P13, eye opening, to P28, the peak of the critical period for rodent visual cortical plasticity. Upon direct stimulation of layer 4 (L4, activity spreads to L2/3 and to L5 at all ages. However, while from eye opening to the peak of the critical period, the amplitude and persistence of the voltage signal decrease, peak activation is reached more quickly and the interlaminar gain increases with age. The lateral spread of activation within layers remains unchanged throughout the time window under analysis. These developmental changes in spatio-temporal patterns of intracortical circuit activation are mediated by differences in the contributions of excitatory and inhibitory synaptic components. Our results demonstrate that after eye opening the circuit in primary visual cortex is refined through a progression of changes that shape the spatio-temporal patterns of circuit activation. Signals become more efficiently propagated across layers through developmentally regulated changes in interlaminar gain.

  17. Functional and structural specific roles of activity-driven BDNF within circuits formed by single spiny stellate neurons of the barrel cortex

    Directory of Open Access Journals (Sweden)

    Qian-Quan eSun

    2014-11-01

    Full Text Available Brain derived neurotrophic factor (BDNF plays key roles in several neurodevelopmental disorders and actions of pharmacological treatments. However it is uncealr how specific BDNF’s effects are on diffeerent circuit components. Current studies have largely focused on the role of BDNF in modification of synaptic development. The precise roles of BDNF in the refinement of a functional circuit in vivo remain unclear. Val66Met polymorphism of BDNF may be associated with increased risk for cognitive impairments and is mediated at least in part by activity-dependent trafficking and/or secretion of BDNF. Using mutant mice that lacked activity-driven BDNF expression (bdnf-KIV, we previously reported that experience regulation of the cortical GABAergic network is mediated by activity-driven BDNF expression. Here, we demonstrate that activity-driven BDNF’s effects on circuits formed by the layer IV spiny stellate cells are highly specific. Structurally, dendritic but not axonal morphology was altered in the mutant. Physiologically, GABAergic but not glutamatergic synapses were severely affected. The effects on GABA transmission occurs via presynaptic alteration of calcium-dependent release probability. These results suggest that neuronal activity through activity-driven BDNF expression, can selectively regulate specific features of layer IV circuits in vivo. We postulate that the role of activity-dependent BDNF is to modulate the computational ability of circuits that relate to the gain control (i.e. feed-forward inhibition; whereas the basic wiring of circuits relevant to the sensory pathway is spared. Gain control modulation within cortical circuits has broad impact on cognitive processing and brain state-transitions. Cognitive behavior and mode is determined by brain states, thus the studying of circuit alteration by endogenous BDNF provides insights into the cellular and molecular mechanisms of diseases mediated by BDNF.

  18. Variable cooling circuit for thermoelectric generator and engine and method of control

    Science.gov (United States)

    Prior, Gregory P

    2012-10-30

    An apparatus is provided that includes an engine, an exhaust system, and a thermoelectric generator (TEG) operatively connected to the exhaust system and configured to allow exhaust gas flow therethrough. A first radiator is operatively connected to the engine. An openable and closable engine valve is configured to open to permit coolant to circulate through the engine and the first radiator when coolant temperature is greater than a predetermined minimum coolant temperature. A first and a second valve are controllable to route cooling fluid from the TEG to the engine through coolant passages under a first set of operating conditions to establish a first cooling circuit, and from the TEG to a second radiator through at least some other coolant passages under a second set of operating conditions to establish a second cooling circuit. A method of controlling a cooling circuit is also provided.

  19. Computer simulation of short-circuiting transfer welding under waveform control on inverter power source

    Institute of Scientific and Technical Information of China (English)

    Yang Lijun; Feng Shengqiang; Dong Tianshun; Li Huan

    2007-01-01

    A simulation model is introduced about the non-linearity process of short-circuiting transfer in CO2 arc welding for displaying the interaction between the inverter power source and welding arc under waveform control. In the simulation model, the feedback signals of current and voltage are taken respectively at the different phase in a short circuit periodic time and applied to the PWM(pulse width modulation) module in a model of inverter power source to control the output of power source. The simulation operation about the dynamic process of CO2 short-circuiting transfer welding is implemented on the founded simulation model with a peak arc current of 400 A and a peak voltage of 35 V, producing the dynamic arc waveforms which can embody the effect of inverter harmonic wave. The simulating waveforms are close to that of welding experiments.

  20. Selecting protective devices for use in rectified control current circuits

    Energy Technology Data Exchange (ETDEWEB)

    Savin, S.N.; Krichevskaya, L.Z.

    1982-11-01

    Power supplies are in widespread use at 35-110 kV substations as sources of control current. These power supplies are rectifying devices which consist of an intermediate transformer with a three-phase bridge rectifier. The advantages of the various types of power supplies are discussed.

  1. Altered regional and circuit resting-state activity associated with unilateral hearing loss.

    Directory of Open Access Journals (Sweden)

    Xingchao Wang

    Full Text Available The deprivation of sensory input after hearing damage results in functional reorganization of the brain including cross-modal plasticity in the sensory cortex and changes in cognitive processing. However, it remains unclear whether partial deprivation from unilateral auditory loss (UHL would similarly affect the neural circuitry of cognitive processes in addition to the functional organization of sensory cortex. Here, we used resting-state functional magnetic resonance imaging to investigate intrinsic activity in 34 participants with UHL from acoustic neuroma in comparison with 22 matched normal controls. In sensory regions, we found decreased regional homogeneity (ReHo in the bilateral calcarine cortices in UHL. However, there was an increase of ReHo in the right anterior insular cortex (rAI, the key node of cognitive control network (CCN and multimodal sensory integration, as well as in the left parahippocampal cortex (lPHC, a key node in the default mode network (DMN. Moreover, seed-based resting-state functional connectivity analysis showed an enhanced relationship between rAI and several key regions of the DMN. Meanwhile, lPHC showed more negative relationship with components in the CCN and greater positive relationship in the DMN. Such reorganizations of functional connectivity within the DMN and between the DMN and CCN were confirmed by a graph theory analysis. These results suggest that unilateral sensory input damage not only alters the activity of the sensory areas but also reshapes the regional and circuit functional organization of the cognitive control network.

  2. Reduction of activation and contamination of reactor circuits

    International Nuclear Information System (INIS)

    After investigation of the metal loss rate of INCOLOY 800 samples by several test series performes at 3420C and 150 bar with different oxygen contents in demineralized water (deionate), the protective gold plating applied on the inner side of the first autoclave system had to be renewed. Within the period of reporting the second autoclave system (same dimensions as the first autoclave system) also provided with an inner gold plating was nearly completed. Also a small sized third autoclave system has been completed which allows to study the metal loss rate to pressurized water of standard stainless steel, the material making up 15% of the inner surface of a primary reactor circuit. Reduction of the oxygen content in deionate by noble gas sweeping, which is much more effective than chemical reduction by hydrazine, was improved in combination with the first autoclave system. Apparently the minimum oxygen content of 0,05 mg/kg required for primary loop water of pressurized reactors can still be lowered by the factor of 20. (orig./RW)

  3. Latch-up control in CMOS integrated circuits

    International Nuclear Information System (INIS)

    The potential for latch-up, a pnpn self-sustaining low impedance state, is inherent in standard bulk CMOS structures. Under normal bias, the parasitic SCR is in its blocking state, but if subjected to a high-voltage spike or if exposed to an ionizing environment, triggering may occur. Prevention of latch-up has been achieved by lifetime control methods such as gold doping or neutron irradiation and by modifying the structure with buried layers. Smaller, next-generation CMOS designs will enhance parasitic action making the problem a concern for other than military or space applications alone. Latch-up control methods presently employed are surveyed. Their adaptability to VSLI designs is analyzed

  4. Controlling the Mdm2-Mdmx-p53 Circuit

    OpenAIRE

    Waning, David L.; Lehman, Jason A.; Batuello, Christopher N.; Mayo, Lindsey D.

    2010-01-01

    The p53 tumor suppressor is a key protein in maintaining the integrity of the genome by inducing either cell cycle arrest or apoptosis following cellular stress signals. Two human family members, Mdm2 and Mdmx, are primarily responsible for inactivating p53 transcription and targeting p53 protein for ubiquitin-mediated degradation. In response to genotoxic stress, post-translational modifications to p53, Mdm2 and Mdmx stabilize and activate p53. The role that phosphorylation of these molecule...

  5. The paraventricular thalamus controls a central amygdala fear circuit

    OpenAIRE

    Penzo, Mario A.; Robert, Vincent; Tucciarone, Jason; Bundel, Dimitri De; Wang, Minghui; Van Aelst, Linda; Darvas, Martin; Parada, Luis F.; Palmiter, Richard; He, Miao; Huang, Z. Josh; Li, Bo

    2015-01-01

    Appropriate responses to an imminent threat brace us for adversities. The ability to sense and predict threatening or stressful events is essential for such adaptive behavior. In the mammalian brain, one putative stress sensor is the paraventricular nucleus of the thalamus (PVT), an area that is readily activated by both physical and psychological stressors 1-3 . However, the role of PVT in the establishment of adaptive behavioral responses remains unclear. Here we show in mice that PVT regul...

  6. Distributed dynamical computation in neural circuits with propagating coherent activity patterns.

    Directory of Open Access Journals (Sweden)

    Pulin Gong

    2009-12-01

    Full Text Available Activity in neural circuits is spatiotemporally organized. Its spatial organization consists of multiple, localized coherent patterns, or patchy clusters. These patterns propagate across the circuits over time. This type of collective behavior has ubiquitously been observed, both in spontaneous activity and evoked responses; its function, however, has remained unclear. We construct a spatially extended, spiking neural circuit that generates emergent spatiotemporal activity patterns, thereby capturing some of the complexities of the patterns observed empirically. We elucidate what kind of fundamental function these patterns can serve by showing how they process information. As self-sustained objects, localized coherent patterns can signal information by propagating across the neural circuit. Computational operations occur when these emergent patterns interact, or collide with each other. The ongoing behaviors of these patterns naturally embody both distributed, parallel computation and cascaded logical operations. Such distributed computations enable the system to work in an inherently flexible and efficient way. Our work leads us to propose that propagating coherent activity patterns are the underlying primitives with which neural circuits carry out distributed dynamical computation.

  7. An Educational Laboratory for Digital Control and Rapid Prototyping of Power Electronic Circuits

    Science.gov (United States)

    Choi, Sanghun; Saeedifard, M.

    2012-01-01

    This paper describes a new educational power electronics laboratory that was developed primarily to reinforce experimentally the fundamental concepts presented in a power electronics course. The developed laboratory combines theoretical design, simulation studies, digital control, fabrication, and verification of power-electronic circuits based on…

  8. Design of programmable logic controller auto power reset circuit for FM transmitter

    Directory of Open Access Journals (Sweden)

    Adisak Pattanajakr

    2016-06-01

    Full Text Available The mono-stereo controller using audio mute clock is used at the International Broadcasting Bureau (IBB FM 106.6 MHz transmitter in Ulaan Baatar, Mongolia since 2010. The major problem of the FM broadcast station was from the frozen Programmable Logic Controller, PLC, which must be manually reset and the report by the VOA listeners. Then, the PLC auto power reset circuit is proposed and built in mono-stereo controller to monitor the operation of the PLC. The circuit is also used to restart the PLC whenever, it is frozen. The cloud router and Transmission Control Protocol/Internet Protocol (TCP/IP to Recommended Standard number 232 (RS-232 converter are used to synchronize the PLC time. From the results, this circuit can improve the transmitter availability and quality of the 24 hours/day broadcast program without affection to the listeners. The reliability of the cloud router is acceptable with low delay of data transfer via the internet connection between Thailand to Mongolia. The cloud router which the IBB leases cloud service from the provider that offers high speed internet up to 1000 Mb/s, via the remote terminal is used for the schedule program and the time synchronization of the PLC correctly. The proposed system is very stable and there is no problem of the frozen PLC whether it connects to the internet or not. Hence, the designed PLC auto power reset circuit can be used to eliminate the frozen PLC problem.

  9. Experiences of activity measurements of primary circuit materials in a WWR-SM research reactor

    International Nuclear Information System (INIS)

    The activity of water and gas samples taken from the primary circuit have been measured nondestructively for more than two years to monitor the technological parameters of the reactor. In the primary water samples 17 fission products and seven activated traces, as well as six radioactive conponents in the gas samples were determined routinely by Ge/Li gamma-spectrometry. (author)

  10. Control of DFIG Wind Turbines Based on Indirect Matrix Converters in Short Circuit Mode to Improve the LVRT Capability

    Directory of Open Access Journals (Sweden)

    Ahmad Khajeh

    2013-01-01

    Full Text Available Nowadays, the doubly-fed induction generators (DFIGs based wind turbines (WTs are the dominant type of WTs. Traditionally, the back-to-back converters are used to excite the rotor circuit of DFIG. In this paper, an indirect matrix converter (IMC is proposed to control the generator. Compared with back-to-back converters, IMCs have numerous advantages such as higher level of robustness, reliability, and reduced size and weight due to the absence of bulky electrolytic capacitor. According to the recent grid codes wind turbines must have low voltage ride-through (LVRT capability. In this paper a new crowbar system is proposed so that along with the control system it protects the IMC from large fault currents and supports the grid voltage dips during grid faults. This crowbar system is provided using the existing converter switches to establish a short circuit mode without any extra circuitry. Even in severe fault conditions, the duration of short circuit mode is quite small so the control system will be activated shortly after the fault to inject reactive power as required by new LVRT standards. Therefore, the new LVRT standards are well satisfied without any extra costs. PSIM simulation results confirm the efficiency of the proposed method.

  11. Benchmark of AC and DC Active Power Decoupling Circuits for Second-Order Harmonic Mitigation in Kilowatt-Scale Single-Phase Inverters

    DEFF Research Database (Denmark)

    Qin, Zian; Tang, Yi; Loh, Poh Chiang;

    2016-01-01

    efficiency and high power density is identified and comprehensively studied, and the commercially available film capacitors, the circuit topologies, and the control strategies adopted for active power decoupling are all taken into account. Then, an adaptive decoupling voltage control method is proposed to...

  12. Apparatus for controlling the firing of rectifiers in polyphase rectifying circuits

    Science.gov (United States)

    Yarema, R.J.

    1979-09-18

    A polyphase rectifier is controlled with precision by a circuit that filters and shifts a reference signal associated with each phase and that starts a ramp signal at a zero crossing of the shifted reference signal. The difference between the ramp signal and an external trigger signal is used to generate a pulse that switches power rectifiers into conduction. The circuit reduces effects of variations that introduce subharmonics into a rectified signal and it can be used for constant or time-varying external trigger signals.

  13. Simulation and primary circuit control of the SP-100 space nuclear power reactor

    International Nuclear Information System (INIS)

    Space nuclear power reactors with thermoelectric conversion are one of the main sources for space application that can provide enough electric power. In this paper we discuss the working conditions, basic structure and operational characteristics of an EMTE pump needed to flow control of a metal liquid nuclear space reactor primary circuit. The BEMTE-1 program is used to study this system during normal operation to simulate the SP-100 american reactor primary cooling circuit and to obtain the actuation point of the system. (author)

  14. Effect of Sensors on the Reliability and Control Performance of Power Circuits in the Web of Things (WoT).

    Science.gov (United States)

    Bae, Sungwoo; Kim, Myungchin

    2016-01-01

    In order to realize a true WoT environment, a reliable power circuit is required to ensure interconnections among a range of WoT devices. This paper presents research on sensors and their effects on the reliability and response characteristics of power circuits in WoT devices. The presented research can be used in various power circuit applications, such as energy harvesting interfaces, photovoltaic systems, and battery management systems for the WoT devices. As power circuits rely on the feedback from voltage/current sensors, the system performance is likely to be affected by the sensor failure rates, sensor dynamic characteristics, and their interface circuits. This study investigated how the operational availability of the power circuits is affected by the sensor failure rates by performing a quantitative reliability analysis. In the analysis process, this paper also includes the effects of various reconstruction and estimation techniques used in power processing circuits (e.g., energy harvesting circuits and photovoltaic systems). This paper also reports how the transient control performance of power circuits is affected by sensor interface circuits. With the frequency domain stability analysis and circuit simulation, it was verified that the interface circuit dynamics may affect the transient response characteristics of power circuits. The verification results in this paper showed that the reliability and control performance of the power circuits can be affected by the sensor types, fault tolerant approaches against sensor failures, and the response characteristics of the sensor interfaces. The analysis results were also verified by experiments using a power circuit prototype. PMID:27608020

  15. Effect of Sensors on the Reliability and Control Performance of Power Circuits in the Web of Things (WoT

    Directory of Open Access Journals (Sweden)

    Sungwoo Bae

    2016-09-01

    Full Text Available In order to realize a true WoT environment, a reliable power circuit is required to ensure interconnections among a range of WoT devices. This paper presents research on sensors and their effects on the reliability and response characteristics of power circuits in WoT devices. The presented research can be used in various power circuit applications, such as energy harvesting interfaces, photovoltaic systems, and battery management systems for the WoT devices. As power circuits rely on the feedback from voltage/current sensors, the system performance is likely to be affected by the sensor failure rates, sensor dynamic characteristics, and their interface circuits. This study investigated how the operational availability of the power circuits is affected by the sensor failure rates by performing a quantitative reliability analysis. In the analysis process, this paper also includes the effects of various reconstruction and estimation techniques used in power processing circuits (e.g., energy harvesting circuits and photovoltaic systems. This paper also reports how the transient control performance of power circuits is affected by sensor interface circuits. With the frequency domain stability analysis and circuit simulation, it was verified that the interface circuit dynamics may affect the transient response characteristics of power circuits. The verification results in this paper showed that the reliability and control performance of the power circuits can be affected by the sensor types, fault tolerant approaches against sensor failures, and the response characteristics of the sensor interfaces. The analysis results were also verified by experiments using a power circuit prototype.

  16. Controlled Conjugated Backbone Twisting for an Increased Open-Circuit Voltage while Having a High Short-Circuit Current in Poly(hexylthiophene) Derivatives

    KAUST Repository

    Ko, Sangwon

    2012-03-21

    Conjugated polymers with nearly planar backbones have been the most commonly investigated materials for organic-based electronic devices. More twisted polymer backbones have been shown to achieve larger open-circuit voltages in solar cells, though with decreased short-circuit current densities. We systematically impose twists within a family of poly(hexylthiophene)s and examine their influence on the performance of polymer:fullerene bulk heterojunction (BHJ) solar cells. A simple chemical modification concerning the number and placement of alkyl side chains along the conjugated backbone is used to control the degree of backbone twisting. Density functional theory calculations were carried out on a series of oligothiophene structures to provide insights on how the sterically induced twisting influences the geometric, electronic, and optical properties. Grazing incidence X-ray scattering measurements were performed to investigate how the thin-film packing structure was affected. The open-circuit voltage and charge-transfer state energy of the polymer:fullerene BHJ solar cells increased substantially with the degree of twist induced within the conjugated backbone-due to an increase in the polymer ionization potential-while the short-circuit current decreased as a result of a larger optical gap and lower hole mobility. A controlled, moderate degree of twist along the poly(3,4-dihexyl-2,2′:5′,2′′- terthiophene) (PDHTT) conjugated backbone led to a 19% enhancement in the open-circuit voltage (0.735 V) vs poly(3-hexylthiophene)-based devices, while similar short-circuit current densities, fill factors, and hole-carrier mobilities were maintained. These factors resulted in a power conversion efficiency of 4.2% for a PDHTT:[6,6]-phenyl-C 71-butyric acid methyl ester (PC 71BM) blend solar cell without thermal annealing. This simple approach reveals a molecular design avenue to increase open-circuit voltage while retaining the short-circuit current. © 2012 American

  17. An Efficiency Improved Active Power Decoupling Circuit with Minimized Implementation Cost

    DEFF Research Database (Denmark)

    Tang, Yi; Blaabjerg, Frede

    2014-01-01

    Active power decoupling techniques are promising solutions for capacitance reduction in single-phase AC/DC or DC/AC systems. This paper proposes a novel circuit topology which can realize the power decoupling function without adding additional active switches into the circuit. Also, the proposed...... topology does not require additional passive component, e.g. inductors or film capacitors for ripple energy storage because this task can be accomplished by the dc-link capacitors themselves, and therefore its implementation cost can be minimized. Another unique feature of the proposed topology...

  18. 荷控忆阻器等效电路分析模型及其电路特性研究%Equivalent circuit analysis model of charge-controlled memristor and its circuit characteristics

    Institute of Scientific and Technical Information of China (English)

    胡丰伟; 包伯成; 武花干; 王春丽

    2013-01-01

    忆阻器是物理上新实现的具有记忆特性的基本二端电路元件。根据ϕ-q关系式的泰勒级数形式构建了荷控忆阻器等效电路分析模型,以三次非线性荷控忆阻器模型为例,对不同参数条件下的荷控忆阻器进行了伏安关系、有无源性等电路特性的理论分析。结果表明:荷控忆阻器的伏安关系具有斜体“8”字形紧磁滞回线特性,随其参数符号的不同,荷控忆阻器呈现出无源性和有源性,导致其电路特性发生相应的变化;相比无源荷控忆阻器,有源荷控忆阻器更适用于作为二次谐波信号产生电路使用。制作了荷控忆阻器特性分析等效电路的实验电路,实验测量结果很好地验证了理论分析结果。%Memristor realized physically is recently a basic two-terminal circuit element with memory property. Based on Taylor series form ofϕ−q relationship, a charge-controlled memristor equivalent circuit analysis model is built. A charge-controlled memristor model with cubic nonlinearity is taken, as an example, to make a theoretical analysis of circuit characteristics, such as voltage-current relationship, active-passive property, and so on, of the charge-controlled memristor with different parameters. Results indicate that the voltage-current relationship of the charge-controlled memristor has an italic”8”shaped hysteresis loop characteristic, and the charge-controlled memristor shows passivity and activity accompanied with the variations of parameter symbols, resulting in the occurrence of the corresponding variations of circuit characteristics;compared with the passive memristor, the active memristor is more suitable for use as a second harmonic signal generation circuit. An experiment circuit is built based on the equivalent circuit of the charge-controlled memristor characteristic analysis, and the experimental results well verify the theoretical analysis.

  19. Design, components, controls and operational experience of mercury circuits

    Energy Technology Data Exchange (ETDEWEB)

    Lielausis, O.

    1996-06-01

    The main activities of the Institute of Physics are connected with magnetohydrodynamics of incompressible media, first at all, liquid metals. Along side with Li, Na, NaK and low temperature eutectic InGaSn, mercury serves as one of the best working medium. A special Hg laboratory complex was built including a 350 m{sup 2} experimental hall. The amount of Hg in use reaches 8x10{sup 3} kg. As an important practical result the development and production of different electromagnetic pumps for heavy metals (Hg, Pb, Bi, Zn, Sn, InGaSn, steel) can be considered. The same can be said about new technologies for Hg chemical treatment (purification). Mercury is used as an effective modeling material for the investigation of a great number of metallurgical processes, as well as for thermohydraulic testing of systems, proposed for other (more aggressive or high temperature) heavy liquid metals. The laboratory is equipped with three easy transferable d=3-5 cm mercury loops as well as with a large closed 12 m long d=10 cm stationary loop. The electromagnetic feeding pump delivers 5 l/s at 5 atm. The loading mercury weights 4.7x10{sup 3} kg. For investigation in magnetohydrodynamics a 2 m long solenoid calculated for a 2 T magnetic field in a d=20cm bore is used, as well as an electromagnet providing 1.5 T in a 15 cm gap between round d=50 cm poles. Since in the case of Hg almost all traditional measuring techniques (including thermoanemometry) can be applied, complex physical problems can be considered. So, results gained in this laboratory, served as a base for ideas about 2D MHD turbulence, possessing all the strange features predicted by theory for 2D turbulence. So, recently it was showed that by means of an outer magnetic field the intensity of heat transfer can be enhanced by an order compared with an ordinary turbulent motion outside the field. Detailed modeling of heat transfer processes typical to the liquid metal blanket of proposed thermonuclear reactors was performed.

  20. 基于有源广义忆阻的无感混沌电路研究∗%Inductorless chaotic circuit based on active generalized memristors

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Equivalently implementing a generalized memristor by using common components and then making a nonlinear circuit with a reliable property, are conducive to experimentally exhibit the nonlinear phenomena of the memristive chaotic circuit and show practical applications in generating chaotic signals. Firstly, based on a memristive diode bridge circuit, a new first-order actively generalized memristor emulator is constructed with no grounded restriction and ease to realize. The mathematical model of the emulator is established and its fingerprints are analyzed by the pinched hysteresis loops with different sinusoidal voltage stimuli. The results verified by experimental measurements indicate that the emulator uses only one operational amplifier and nine elementary electronic circuit elements and is an active voltage-controlled generalized memristor. Secondly, by parallelly connecting the proposed emulator to a capacitor and then linearly coupling with an RC bridge oscillator, a memristor based chaotic circuit without any inductance element is constructed. The dynamical model of the inductorless memristive chaotic circuit is established and the phase portraits of the chaotic attractor with typical circuit parameters are obtained numerically. The dissipativity, equilibrium points, and stabilities are derived, which indicate that in the phase space of the inductorless memristive chaotic circuit there exists a dissipative area where are distributed two unstable nonzero saddle-foci and a non-dissipative area containing an unstable origin saddle point. Furthermore, by utilizing the bifurcation diagram, Lyapunov exponent spectra, and phase portraits, the dynamical behaviors of the inductorless memristive chaotic circuit are investigated. Results show that with the evolution of the parameter value of the coupling resistor, the complex nonlinear phenomena of the coexisting bifurcation modes and coexisting attractors under two different initial conditions of the state variables

  1. High-frequency link dc/ac converter with suppressed voltage clamp circuits -- Naturally commutated phase angle control with self turn-off devices

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, Mikihiko; Nagai, Masaki; Mochizuki, Masayuki; Nabae, Akira [Tokyo Inst. of Polytechnics, Kanagawa (Japan). Dept. of Electronic Engineering

    1996-03-01

    High-frequency (HF) link circuit topology is advantageous in realizing compact and light-weight power converters for UPS systems, new energy systems, etc. Among its several circuit configurations, so called cycloconverter type dc/ac converter has its inherent merit of bidirectional power flow and fewer power conversion stages. But, without additional voltage clamp circuit, voltage surge occurs at the moment of PWM switchings of the cycloconverter due to the stored energy in the leakage inductance at the HF transformer. In this paper, a new approach which adopts only natural-commutation phase angle control for the cycloconverter stage instead of PWM is proposed to remove such voltage clamp circuits. Experimental results of the prototype system which include the application as an ac active filter are also shown.

  2. Anabolic steroids alter the physiological activity of aggression circuits in the lateral anterior hypothalamus.

    Science.gov (United States)

    Morrison, T R; Sikes, R W; Melloni, R H

    2016-02-19

    Syrian hamsters exposed to anabolic/androgenic steroids (AAS) during adolescence consistently show increased aggressive behavior across studies. Although the behavioral and anatomical profiles of AAS-induced alterations have been well characterized, there is a lack of data describing physiological changes that accompany these alterations. For instance, behavioral pharmacology and neuroanatomical studies show that AAS-induced changes in the vasopressin (AVP) neural system within the latero-anterior hypothalamus (LAH) interact with the serotonin (5HT) and dopamine (DA) systems to modulate aggression. To characterize the electrophysiological profile of the AAS aggression circuit, we recorded LAH neurons in adolescent male hamsters in vivo and microiontophoretically applied agonists and antagonists of aggressive behavior. The interspike interval (ISI) of neurons from AAS-treated animals correlated positively with aggressive behaviors, and adolescent AAS exposure altered parameters of activity in regular firing neurons while also changing the proportion of neuron types (i.e., bursting, regular, irregular). AAS-treated animals had more responsive neurons that were excited by AVP application, while cells from control animals showed the opposite effect and were predominantly inhibited by AVP. Both DA D2 antagonists and 5HT increased the firing frequency of AVP-responsive cells from AAS animals and dual application of AVP and D2 antagonists doubled the excitatory effect of AVP or D2 antagonist administration alone. These data suggest that multiple DA circuits in the LAH modulate AAS-induced aggressive responding. More broadly, these data show that multiple neurochemical interactions at the neurophysiological level are altered by adolescent AAS exposure. PMID:26691962

  3. Optogenetic spatial and temporal control of cortical circuits on a columnar scale.

    Science.gov (United States)

    Roy, Arani; Osik, Jason J; Ritter, Neil J; Wang, Shen; Shaw, James T; Fiser, József; Van Hooser, Stephen D

    2016-02-01

    Many circuits in the mammalian brain are organized in a topographic or columnar manner. These circuits could be activated-in ways that reveal circuit function or restore function after disease-by an artificial stimulation system that is capable of independently driving local groups of neurons. Here we present a simple custom microscope called ProjectorScope 1 that incorporates off-the-shelf parts and a liquid crystal display (LCD) projector to stimulate surface brain regions that express channelrhodopsin-2 (ChR2). In principle, local optogenetic stimulation of the brain surface with optical projection systems might not produce local activation of a highly interconnected network like the cortex, because of potential stimulation of axons of passage or extended dendritic trees. However, here we demonstrate that the combination of virally mediated ChR2 expression levels and the light intensity of ProjectorScope 1 is capable of producing local spatial activation with a resolution of ∼200-300 μm. We use the system to examine the role of cortical activity in the experience-dependent emergence of motion selectivity in immature ferret visual cortex. We find that optogenetic cortical activation alone-without visual stimulation-is sufficient to produce increases in motion selectivity, suggesting the presence of a sharpening mechanism that does not require precise spatiotemporal activation of the visual system. These results demonstrate that optogenetic stimulation can sculpt the developing brain. PMID:26631152

  4. APPLICATION OF CIRCUIT SIMULATION IN HARDWARE DESIGN FOR ELECTRONIC CONTROL HIGH PRESSURE COMMON-RAIL FUEL SYSTEM OF DIESEL ENGINE

    Institute of Scientific and Technical Information of China (English)

    Tan Wenchun; Yu Shitao; Yang Lin; Zhuo Bin

    2005-01-01

    By means of circuit simulation, hardware of electronic control unit (ECU) of high pressure common-rail electronic control fuel system for diesel engine is designed. According to the system requirements for hardware of ECU, signal-processing circuit of variable reluctance (VR) sensor, filter circuit for input signal, high voltage power circuit and driver and protection circuit of solenoid are simulated as emphases. Difficulties of wide scope of VR sensor output signal, efficiency of high voltage power and reliable and swift driver of solenoid are solved. The results of simulation show that the hardware meets the requirement of the fuel system. At the same time, circuit simulation can greatly increase quality of the design, alleviate design labor and shorten design time.

  5. Circuit model of the ITER-like antenna for JET and simulation of its control algorithms

    International Nuclear Information System (INIS)

    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. At 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 design and

  6. Circuit model of the ITER-like antenna for JET and simulation of its control algorithms

    Science.gov (United States)

    Durodié, Frédéric; Dumortier, Pierre; Helou, Walid; Křivská, Alena; Lerche, Ernesto

    2015-12-01

    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. At 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 design and

  7. Circuit model of the ITER-like antenna for JET and simulation of its control algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Durodié, Frédéric, E-mail: frederic.durodie@rma.ac.be; Křivská, Alena [LPP-ERM/KMS, TEC Partner, Brussels (Belgium); Dumortier, Pierre; Lerche, Ernesto [LPP-ERM/KMS, TEC Partner, Brussels (Belgium); JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Helou, Walid [CEA, IRFM, F-13108 St-Paul-Lez-Durance (France); Collaboration: EUROfusion Consortium

    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. At 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 design and

  8. Collective of mechatronics circuit

    International Nuclear Information System (INIS)

    This book is composed of three parts, which deals with mechatronics system about sensor, circuit and motor. The contents of the first part are photo sensor of collector for output, locating detection circuit with photo interrupts, photo sensor circuit with CdS cell and lamp, interface circuit with logic and LED and temperature sensor circuit. The second part deals with oscillation circuit with crystal, C-R oscillation circuit, F-V converter, timer circuit, stability power circuit, DC amp and DC-DC converter. The last part is comprised of bridge server circuit, deformation bridge server, controlling circuit of DC motor, controlling circuit with IC for PLL and driver circuit of stepping motor and driver circuit of Brushless.

  9. A predictive control algorithm for an active three-phase power filter

    OpenAIRE

    R.V. Vlasenko; Bialobrzeski, O. V.

    2014-01-01

    The paper deals with grid connection circuits for active filters, structures of active power filter control systems, and methods based on full capacity components determination. The existing structures of active power filter control and control algorithm adjustment for valve commutation loss reduction are analyzed. A predictive control algorithm for an active three-phase power filter is introduced.

  10. Core Transcriptional Regulatory Circuit Controlled by the TAL1 Complex in Human T-cell Acute Lymphoblastic Leukemia

    OpenAIRE

    Sanda, Takaomi; Lawton, Lee N.; Barrasa, M. Inmaculada; Fan, Zi Peng; Kohlhammer, Holger; Gutierrez, Alejandro; Ma, Wenxue; Tatarek, Jessica; Ahn, Yebin; Kelliher, Michelle A.; Jamieson, Catriona H.M.; Staudt, Louis M.; Young, Richard A.; Look, A. Thomas

    2012-01-01

    The oncogenic transcription factor TAL1/SCL is aberrantly expressed in over 40% of cases of human T-cell acute lymphoblastic leukemia (T-ALL), emphasizing its importance in the molecular pathogenesis of T-ALL. Here we identify the core transcriptional regulatory circuit controlled by TAL1 and its regulatory partners HEB, E2A, LMO1/2, GATA3 and RUNX1. We show that TAL1 forms a positive interconnected auto-regulatory loop with GATA3 and RUNX1, and that the TAL1 complex directly activates the MY...

  11. Threshold flux-controlled memristor model and its equivalent circuit implementation

    International Nuclear Information System (INIS)

    Modeling a memristor is an effective way to explore the memristor properties due to the fact that the memristor devices are still not commercially available for common researchers. In this paper, a physical memristive device is assumed to exist whose ionic drift direction is perpendicular to the direction of the applied voltage, upon which, corresponding to the HP charge-controlled memristor model, a novel threshold flux-controlled memristor model with a window function is proposed. The fingerprints of the proposed model are analyzed. Especially, a practical equivalent circuit of the proposed model is realized, from which the corresponding experimental fingerprints are captured. The equivalent circuit of the threshold memristor model is appropriate for various memristors based breadboard experiments. (interdisciplinary physics and related areas of science and technology)

  12. Controllable cross-Kerr interaction between microwave photons in circuit quantum electrodynamics

    Institute of Scientific and Technical Information of China (English)

    Wu Qin-Qin; Liao Jie-Qiao; Kuang Le-Man

    2011-01-01

    We propose a scheme to enable a controllable cross-Kerr interaction between microwave photons in a circuit quantum electrodynamics (QED) system. In this scheme we use two transmission-line resonators (TLRs) and one superconducting quantum interference device (SQUID) type charge qubit, which acts as an artificial atom. It is shown that in the dispersive regime of the circuit-QED system, a controllable cross-Kerr interaction can be obtained by properly preparing the initial state of the qubit, and a large cross-phase shift between two microwave fields in the two TLRs can then be reached. Based on this cross-Kerr interaction, we show how to create a macroscopic entangled state between the two TLRs.

  13. A strategy for adaptive synchronization of an electrical chaotic circuit based on nonlinear control

    International Nuclear Information System (INIS)

    This paper deals with the adaptive synchronization of an electrical chaotic oscillator through a nonlinear control law. The nonlinear controller is designed to synchronize two identical chaotic systems. Lyapunov stability theory is applied to prove that under some conditions the drive-response system can achieve practical synchronization. The designed controller contains only continuous nonlinear terms existing in the dynamical systems and is easy to implement in practice. As an illustrative example to verify the validity of the proposed method, a hyperbolic tangent-based electrical and chaotic circuit is chosen and its dynamics is briefly investigated to demonstrate its chaotic behavior.

  14. A Dynamic Magnetic Equivalent Circuit Model For Design And Control Of Wound Rotor Synchronous Machines

    OpenAIRE

    Wang, Xiaoqi

    2013-01-01

    Recently, a new magnetic equivalent circuit (MEC) model was developed to support automated multi-objective design of wound-rotor synchronous machines (WRSMs). In this research, the MEC model and its application have been enhanced. Initial enhancement has focused on using the MEC model to explore machine design and control as a unified problem. Excitation strategies for optimal steady-state performance have been developed. The optimization is implemented in two phases. First, stator and field ...

  15. Modeling and Verification for Track Circuit Encoding in Train Control Center Based on UML and TA

    OpenAIRE

    Lei Yuan; Lijuan Wang; Dewang Chen; Amie Albrecht

    2014-01-01

    The correct implementation of Train Control Center (TCC) software has great significance on the safe operation of high-speed railways. There are some problems in the currently used timed automata (TA) method for modeling TCC software, such as subjectivity and uncertainty in the modeling.  In order to better verify the features of TCC software, this paper presents a new modeling method which combines Unified Modeling Language (UML) and Timed Automata (TA). As track circuit encoding functi...

  16. Software-Controlled Next Generation Optical Circuit Switching for HPC and Cloud Computing Datacenters

    OpenAIRE

    Muhammad Imran; Martin Collier; Pascal Landais; Kostas Katrinis

    2015-01-01

    In this paper, we consider the performance of optical circuit switching (OCS) systems designed for data center networks by using network-level simulation. Recent proposals have used OCS in data center networks but the relatively slow switching times of OCS-MEMS switches (10–100 ms) and the latencies of control planes in these approaches have limited their use to the largest data center networks with workloads that last several seconds. Herein, we extend the applicability and generality of the...

  17. Circuit Resistance Exercise Improves Glycemic Control and Adipokines in Females with Type 2 Diabetes Mellitus

    OpenAIRE

    Nam Hwoeh Yeo; Young Jun Kim; Hye-Jeong Lee 167; Dukkuy Kim; Ki Ok Shin; Jin Hee Woo; Sunghwun Kang

    2009-01-01

    The aim of study was to evaluate whether circuit resistance exercise (CE) improves glycemic control and adipokine levels in comparison with walking exercise (WE) in 15 adult postmenopausal Korean females with type 2 diabetes mellitus (T2DM). The participants were randomly assigned to either the CE or WE group. Subjects exercised for 1 h, three times per week for 12 weeks. The parameters measured were body composition, respiratory rate, blood glucose, insulin and adipokines. The body compositi...

  18. Activation product transport in the helium cooling circuit of the SEAFP Plant Model 1

    International Nuclear Information System (INIS)

    This paper presents results using the steady-state activation transport and deposition code TRAP. Activation of the helium coolant and pipe wall deposits are calculated at important locations of the primary circuit loop of the SEAFP Plant Model 1. The dominant sources of active material in the coolant comprise a nuclear sputtering mechanism and direct generation in the coolant due to the neutron-coolant interaction. Coolant activity behavior is shown to be dictated by the volatile nuclides whereas surface activity behavior is dictated by the non-volatiles. Resulting hazards are estimated to be extremely small

  19. Vector Control of Three-Phase Induction Motor with Two Stator Phases Open-Circuit

    Directory of Open Access Journals (Sweden)

    Seyed Hesam Asgari

    2015-06-01

    Full Text Available Variable frequency drives are used to provide reliable dynamic systems and significant reduction in usage of energy and costs of the induction motors. Modeling and control of faulty or an unbalanced three-phase induction motor is obviously different from healthy three-phase induction motor. Using conventional vector control techniques such as Field-Oriented Control (FOC for faulty three-phase induction motor, results in a significant torque and speed oscillation. This research presented a novel method for vector control of three-phase induction motor under fault condition (two-phase open circuit fault. The proposed method for vector control of faulty machine is based on rotor FOC method. A comparison between conventional and modified controller shows that the modified controller has been significantly reduced the torque and speed oscillations.

  20. Design of monitoring circuit of PMT HV power supply control system of LASCAR scintillator array detector at RIBLL

    International Nuclear Information System (INIS)

    It is described that the monitoring circuit of PMT HV power supply control system of LASCAR in this paper, which is based on CC123 HV power supply module supplied by Beijing HAMAMATSU Phonetics Co.. The detailed design of this monitoring circuit, which has combined MCU and Personal Computer, is presented. (authors)

  1. [PhysioFlex: a target-controlled self-regulating closed-circuit inhalation anesthesia regulator].

    Science.gov (United States)

    Nathan, N; Sperandio, M; Erdmann, W; Westerkamp, B; Van Dijk, G; Scherpereel, P; Feiss, P

    1997-01-01

    Physi Flex is the first commercially available apparatus capable for quantitative, or self-regulating target controlled inhalational anaesthesia, with a totally closed circuit, in adults and children. The fresh gas supply to the circuit is intermittent, automatically regulated by continuous monitoring of the volume and composition of the gas mixture in the breathing circuit. The circle system includes, instead of the two conventional one way valves, a blower creating a continuous unidirectional flow at 70 L.min-1. In addition to the CO2-absorber it contains an absorber with carbon, absorbing the anaesthetic vapour when switched into the circuit. The ventilator consists of four ventilating chambers, each one with a membrane separating the patient and the motor compartments. The displacement of the membranes generates and measures the tidal volume. Automatic ventilation is achieved by electric valves and motor gas, and manual ventilation using a bag. Spontaneous ventilation is also possible. The machine is operated via a computer with selects the number of ventilating chambers (one, two or four), and the tidal volume between 50 and 2,000 mL, depending on age, gender and weight of the patient. The computer maintains the gas volume and the gas and vapour concentrations at their preset values. The O2-flow and consumption, the N2O flow and uptake, FICO2 and FETCO2, FI and FET of the volatile anaesthetic, all other important data are displayed in a numerical and graphical form on a color screen and registered for a delayed analysis. The end tidal concentration of the volatile anaesthetic drives a stepmotor with a syringe containing the selected volatile anaesthetic agent with is directly injected into the breathing circuit where it is vaporized. Therefore the concentration of the anaesthetic vapour can be instantaneously increased with this injector at induction and lowered at end of anaesthesia with the carbon absorber, and the fresh gas consumption is significantly

  2. Fuzzy control of carbon dioxide short circuit transfer welding based on reducing dependence of operating skills

    Institute of Scientific and Technical Information of China (English)

    王雅生; 蔡洪能; 张庆; 曲海英

    2002-01-01

    In order to reduce dependence of operating skill ,fuzzy control system is developed, the core of which is a 16 bit Single Chip Microcomputer of Intel 80C196KC.It is realized by software programming. In this system two fuzzy controller are designed. The PID parameter self-adjusting fuzzy controller is used to compensate welding current deviation in the process of arc voltage optimized control. To obtain the optimum result of ultimate frequency of short circuit transfer, the self-optimizing fuzzy controller carries out the arc voltage self-optimizing by under the condition of the given welding current. Arc voltage and welding current are kept the optimum matching relationship by two fuzzy controllers.

  3. Fluorescence-based monitoring of in vivo neural activity using a circuit-tracing pseudorabies virus.

    Directory of Open Access Journals (Sweden)

    Andrea E Granstedt

    Full Text Available The study of coordinated activity in neuronal circuits has been challenging without a method to simultaneously report activity and connectivity. Here we present the first use of pseudorabies virus (PRV, which spreads through synaptically connected neurons, to express a fluorescent calcium indicator protein and monitor neuronal activity in a living animal. Fluorescence signals were proportional to action potential number and could reliably detect single action potentials in vitro. With two-photon imaging in vivo, we observed both spontaneous and stimulated activity in neurons of infected murine peripheral autonomic submandibular ganglia (SMG. We optically recorded the SMG response in the salivary circuit to direct electrical stimulation of the presynaptic axons and to physiologically relevant sensory stimulation of the oral cavity. During a time window of 48 hours after inoculation, few spontaneous transients occurred. By 72 hours, we identified more frequent and prolonged spontaneous calcium transients, suggestive of neuronal or tissue responses to infection that influence calcium signaling. Our work establishes in vivo investigation of physiological neuronal circuit activity and subsequent effects of infection with single cell resolution.

  4. Controllable preparation of two-mode entangled coherent states in circuit QED

    Science.gov (United States)

    Ji, Ying-Hua; Liu, Yong-Mei

    2014-11-01

    Although the multi-level structure of superconducting qubits may result in calculation errors, it can be rationally used to effectively improve the speed of gate operations. Utilizing a current-biased Josephson junction (λ-type rf-SQUID) as a tunable coupler for superconducting transmission line resonators (TLRs), under the large detuning condition, we demonstrate the controllable generation of entangled coherent states in circuit quantum electrodynamics (circuit QED). The coupling between the TLRs and the qubit can be effectively regulated by an external bias current or coupling capacitor. Further investigations indicate that the maximum entangled state can be obtained through measuring the excited state of the superconducting qubits. Then, the influence of the TLR decay on the prepared entangled states is analyzed.

  5. Simulating Experiment and Circuit Simulation of RTD/HPT Photo-Controlled MOBILE

    Institute of Scientific and Technical Information of China (English)

    齐海涛; 张之圣; 郭维廉; 钟明; 梁惠来; 张世林

    2004-01-01

    The MOBILE is a logic element realizing the monostable-bistable transition of a circuit that consists of two resonant tunneling transistors-the resonant tunneling diodes (RTDs) connected in series. It has several advantages including multiple inputs and multiple functions. In this paper, by connecting a heterojunction phototransistor (HPT) with the MOBILE, a novel optoelectronic functional device can be got, which presents the function of both photocurrent switching and photocurrent latching. These behaviors have been demonstrated for the first time by simulating experiments and circuit simulations, with RTDs firstly manufactured in China. Research indicates that the novel photo-controlled MOBILE has the same logic functions as conventional electrical MOBILE except for with light as an input signal.

  6. A 2.4-GHz SiGe HBT power amplifier with bias current controlling circuit

    Institute of Scientific and Technical Information of China (English)

    Peng Yanjun; Song Jiayou; Wang Zhigong; Tsang K F

    2009-01-01

    A 2.4-GHz SiGe HBT power amplifier (PA) with a novel bias current controlling circuit has been realized in IBM 0.35-μm SiGe BiCMOS technology, BiCMOS5PAe. The bias circuit switches the quiescent current to make the PA operate in a high or low power mode. Under a single supply voltage of 3.5 V, the two-stage mode-switchable power amplifier provides a PAE improvement up to 56.7% and 19.2% at an output power of 0 and 20 dBm, respectively, with a reduced quiescent current in the low power mode as compared to only operating the PA in the high power mode. The die size is only 1.32 × 1.37 mm2.

  7. Benchmark of AC and DC active power decoupling circuits for second-order harmonic mitigation in kW-scale single-phase inverters

    DEFF Research Database (Denmark)

    Qin, Zian; Tang, Yi; Loh, Poh Chiang; Blaabjerg, Frede

    This paper presents the benchmark study of ac and dc active power decoupling circuits for second-order harmonic mitigation in kW-scale single-phase inverters. First of all, the best solutions of active power decoupling to achieve high efficiency and power density are identified and comprehensively...... studied, where the commercially available film capacitors, circuit topologies, and control strategies for active power decoupling are all taken into account. Then, an adaptive decoupling voltage control method is proposed to further improve the performance of dc decoupling in terms of efficiency and...... reliability. The feasibility and superiority of the identified solution for active power decoupling together with the proposed adaptive decoupling voltage control method are finally verified by both the experimental results obtained on a 2 kW single-phase inverter....

  8. Design Of Start-up Power Circuit For Control Power Supplies With Wide Input Voltage Variation

    OpenAIRE

    Saichand, K; Kumrawat, Akshay; JOHN, VINOD

    2013-01-01

    This paper presents the design of a start up power circuit for a control power supply (CPS) which feeds power to the sub-systems of High Power Converters (HPC). The sub-systems such as gate drive card, annunciation card, protection and delay card etc; needs to be provided power for the operation of a HPC. The control power supply (CPS) is designed to operate over a wide range of input voltage from 90Vac to 270Vac. The CPS output supplies power at a desired voltage of Vout =24V to the auxil...

  9. Condition based maintenance of gas circuit breaker using synchronous switching control

    International Nuclear Information System (INIS)

    CBM(Condition Based Maintenance) attracts the attention as a resolution of the request for the maintenance cost reduction of power electrical equipments. CBM is to maintain the necessary contents at the optimum timing. This maintenance timing is planed according to the trend of equipments condition information. Especially at the highly reliable equipments like a GIS(Gas Insulated Switchgear), it is expected to optimize the maintenance period. We describe the applicable CBM of GCB (Gas Circuit Breaker) using the operation time data that are the control one of the Synchronous Switching Controller. (author)

  10. Pulsewidth modulated DC-to-DC power conversion circuits, dynamics, and control designs

    CERN Document Server

    Choi, Byungcho

    2013-01-01

    This is the definitive reference for anyone involved in pulsewidth modulated DC-to-DC power conversion Pulsewidth Modulated DC-to-DC Power Conversion: Circuits, Dynamics, and Control Designs provides engineers, researchers, and students in the power electronics field with comprehensive and complete guidance to understanding pulsewidth modulated (PWM) DC-to-DC power converters. Presented in three parts, the book addresses the circuitry and operation of PWM DC-to-DC converters and their dynamic characteristics, along with in-depth discussions of control design of PWM DC-to

  11. A flexible organic active matrix circuit fabricated using novel organic thin film transistors and organic light-emitting diodes

    KAUST Repository

    Gutiérrez-Heredia, Gerardo

    2010-10-04

    We present an active matrix circuit fabricated on plastic (polyethylene naphthalene, PEN) and glass substrates using organic thin film transistors and organic capacitors to control organic light-emitting diodes (OLEDs). The basic circuit is fabricated using two pentacene-based transistors and a capacitor using a novel aluminum oxide/parylene stack (Al2O3/ parylene) as the dielectric for both the transistor and the capacitor. We report that our circuit can deliver up to 15 μA to each OLED pixel. To achieve 200 cd m-2 of brightness a 10 μA current is needed; therefore, our approach can initially deliver 1.5× the required current to drive a single pixel. In contrast to parylene-only devices, the Al2O 3/parylene stack does not fail after stressing at a field of 1.7 MV cm-1 for >10 000 s, whereas \\'parylene only\\' devices show breakdown at approximately 1000 s. Details of the integration scheme are presented. © 2010 IOP Publishing Ltd.

  12. Intersegmental coordination of cockroach locomotion: adaptive control of centrally coupled pattern generator circuits

    Directory of Open Access Journals (Sweden)

    Einat eFuchs

    2011-01-01

    Full Text Available Animals’ ability to demonstrate both stereotyped and adaptive locomotor behavior is largely dependent on the interplay between centrally-generated motor patterns and the sensory inputs that shape them. We utilized a combined experimental and theoretical approach to investigate the relative importance of CPG interconnections vs. intersegmental afferents in the cockroach: an animal that is renowned for rapid and stable locomotion. We simultaneously recorded coxal levator and depressor motor neurons (MN in the thoracic ganglia of Periplaneta americana, while sensory feedback was completely blocked or allowed only from one intact stepping leg. In the absence of sensory feedback, we observed a coordination pattern with consistent phase relationship that shares similarities with a double tripod gait, suggesting central, feedforward control. This intersegmental coordination pattern was then reinforced in the presence of sensory feedback from a single stepping leg. Specifically, we report on transient stabilization of phase differences between activity recorded in the middle and hind thoracic MN following individual front-leg steps, suggesting a role for afferent phasic information in the coordination of motor circuits at the different hemiganglia. Data were further analyzed using stochastic models of coupled oscillators and maximum likelihood techniques to estimate underlying physiological parameters, such as uncoupled endogenous frequencies of hemisegmental oscillators and coupling strengths and directions. We found that descending ipsilateral coupling is stronger than ascending coupling, while left-right coupling in both the meso- and meta-thoracic ganglia appear to be symmetrical. We discuss our results in comparison with recent findings in stick insects that share similar neural and body architectures, and argue that the two species may exemplify opposite extremes of a fast-slow locomotion continuum, mediated through different intersegmental

  13. Impaired activity-dependent neural circuit assembly and refinement in autism spectrum disorder genetic models

    Directory of Open Access Journals (Sweden)

    Caleb Andrew Doll

    2014-02-01

    Full Text Available Early-use activity during circuit-specific critical periods refines brain circuitry by the coupled processes of eliminating inappropriate synapses and strengthening maintained synapses. We theorize these activity-dependent developmental processes are specifically impaired in autism spectrum disorders (ASDs. ASD genetic models in both mouse and Drosophila have pioneered our insights into normal activity-dependent neural circuit assembly and consolidation, and how these developmental mechanisms go awry in specific genetic conditions. The monogenic Fragile X syndrome (FXS, a common cause of heritable ASD and intellectual disability, has been particularly well linked to defects in activity-dependent critical period processes. The Fragile X Mental Retardation Protein (FMRP is positively activity-regulated in expression and function, in turn regulates excitability and activity in a negative feedback loop, and appears to be required for the activity-dependent remodeling of synaptic connectivity during early-use critical periods. The Drosophila FXS model has been shown to functionally conserve the roles of human FMRP in synaptogenesis, and has been centrally important in generating our current mechanistic understanding of the FXS disease state. Recent advances in Drosophila optogenetics, transgenic calcium reporters, highly-targeted transgenic drivers for individually-identified neurons, and a vastly improved connectome of the brain are now being combined to provide unparalleled opportunities to both manipulate and monitor activity-dependent processes during critical period brain development in defined neural circuits. The field is now poised to exploit this new Drosophila transgenic toolbox for the systematic dissection of activity-dependent mechanisms in normal versus ASD brain development, particularly utilizing the well-established Drosophila FXS disease model.

  14. Microcontroller based instrumentation for heater control circuit of tin oxide based hydrogen sensor

    International Nuclear Information System (INIS)

    A thin film sensor based on tin oxide developed in IGCAR is used to monitor very low levels of hydrogen (concentration ranging from 2 ppm to 80 ppm). The heater and the sensor patterns are integrated on a miniature alumina substrate and necessary electrical leads are taken out. For proper functioning of the sensor, the heater has to be maintained at a constant temperature of 350°C. The sensor output (voltage signal) varies with H2 concentration. In fast breeder reactors, liquid sodium is used as coolant. The sensor is used to detect water/steam leak in secondary sodium circuit. During the start up of the reactor, steam leak into sodium circuit generates hydrogen gas as a product that doesn't dissolve in sodium, but escapes to the surge tank containing argon i.e. in cover gas plenum of sodium circuit. On-line monitoring of hydrogen in cover gas is done to detect an event of water/steam leakage. The focus of this project is on the instrumentation pertaining to the temperature control for the sensor heater. The tin oxide based hydrogen sensor is embedded in a substrate which consists of a platinum heater, essentially a resistor. There is no provision of embedding a temperature sensor on the heater surface due to the physical constraints, without which maintaining a constant heater temperature is a complex task

  15. Simple voltage-controlled current source for wideband electrical bioimpedance spectroscopy: circuit dependences and limitations

    International Nuclear Information System (INIS)

    In this work, the single Op-Amp with load-in-the-loop topology as a current source is revisited. This circuit topology was already used as a voltage-controlled current source (VCCS) in the 1960s but was left unused when the requirements for higher frequency arose among the applications of electrical bioimpedance (EBI). The aim of the authors is not only limited to show that with the currently available electronic devices it is perfectly viable to use this simple VCCS topology as a working current source for wideband spectroscopy applications of EBI, but also to identify the limitations and the role of each of the circuit components in the most important parameter of a current for wideband applications: the output impedance. The study includes the eventual presence of a stray capacitance and also an original enhancement, driving with current the VCCS. Based on the theoretical analysis and experimental measurements, an accurate model of the output impedance is provided, explaining the role of the main constitutive elements of the circuit in the source's output impedance. Using the topologies presented in this work and the proposed model, any electronic designer can easily implement a simple and efficient current source for wideband EBI spectroscopy applications, e.g. in this study, values above 150 kΩ at 1 MHz have been obtained, which to the knowledge of the authors are the largest values experimentally measured and reported for a current source in EBI at this frequency

  16. Simple voltage-controlled current source for wideband electrical bioimpedance spectroscopy: circuit dependences and limitations

    Science.gov (United States)

    Seoane, F.; Macías, R.; Bragós, R.; Lindecrantz, K.

    2011-11-01

    In this work, the single Op-Amp with load-in-the-loop topology as a current source is revisited. This circuit topology was already used as a voltage-controlled current source (VCCS) in the 1960s but was left unused when the requirements for higher frequency arose among the applications of electrical bioimpedance (EBI). The aim of the authors is not only limited to show that with the currently available electronic devices it is perfectly viable to use this simple VCCS topology as a working current source for wideband spectroscopy applications of EBI, but also to identify the limitations and the role of each of the circuit components in the most important parameter of a current for wideband applications: the output impedance. The study includes the eventual presence of a stray capacitance and also an original enhancement, driving with current the VCCS. Based on the theoretical analysis and experimental measurements, an accurate model of the output impedance is provided, explaining the role of the main constitutive elements of the circuit in the source's output impedance. Using the topologies presented in this work and the proposed model, any electronic designer can easily implement a simple and efficient current source for wideband EBI spectroscopy applications, e.g. in this study, values above 150 kΩ at 1 MHz have been obtained, which to the knowledge of the authors are the largest values experimentally measured and reported for a current source in EBI at this frequency.

  17. The SlowControl System for the TRD Gas Circuit of the Alpha Magnetic Spectrometer

    International Nuclear Information System (INIS)

    The AMS-02 detector was installed on May 2011 on the International Space Station and has since collected billions of cosmic ray events. The Transition Radiation Detector (TRD) of AMS-02 is a key element to identify positrons in Cosmic Rays with respect to the much more abundant protons. The transition radiation generated by charged particles going through a fleece of propylene radiator is captured by modules of straw tubes interleaved with the fleece layers. The straw tubes are filled with a Xe/CO2 mixture. Due to gas diffusion, such mixture has to be refilled periodically in space during the entire life cycle of AMS. The TRD is equipped with a GasCircuit, containing vessels for Xe and CO2 storage, and all the actuators and sensors needed for the composition of the mixture and to refill the TRD straw tubes. This paper describes the architecture of the (GasCircuitSlowControlsystem (the UGC) that is used to monitor and control the GasCircuit, the qualification procedure for use in space, and the performance of the system after one year of operation on the International Space Station

  18. A novel mixed-synchronization phenomenon in coupled Chua's circuits via non-fragile linear control

    Institute of Scientific and Technical Information of China (English)

    Wang Jun-Wei; Ma Qing-Hua; Zeng Li

    2011-01-01

    Dynamical variables of coupled nonlinear oscillators can exhibit different synchronization patterns depending on the designed coupling scheme.In this paper,a non-fragile linear feedback control strategy with multiplicative controller gain uncertainties is proposed for realizing the mixed-synchronization of Chua's circuits connected in a drive-response configuration.In particular,in the mixed-synchronization regime,different state variables of the response system can evolve into complete synchronization,anti-synchronization and even amplitude death simultaneously with the drive variables for an appropriate choice of scaling matrix.Using Lyapunov stability theory,we derive some sufficient criteria for achieving global mixed-synchronization.It is shown that the desired non-fragile state feedback controller can be constructed by solving a set of linear matrix inequalities(LMIs).Numerical simulations are also provided to demonstrate the effectiveness of the proposed control approach.

  19. Efficacy of biofouling control measures in cooling water circuits of MAPS

    International Nuclear Information System (INIS)

    The Madras Atomic Power Station (MAPS) operates on a once through mode using seawater at the rate of 35 m3s-1 for condenser cooling purposes. Low level continuous chlorination (0.2 ± 0.1 mg L-1 TRO) and twice a week booster dosing (0.4 ± 0.2 mg L-1 TRO) for eight hours is practiced. In addition active bromide is being dosed ahead of the process seawater heat exchangers, 0.15 - 0.2 mg L-1for fouling control. Biofouling load in the cooling water circuits of UNIT-2 after a period of 24 months of operation was assessed during maintenance shutdown with a view to assess the efficacy of present chlorination regime. Different sections of the cooling circuit have unique geometries, structural materials, flow paths and environmental conditions (velocity, temperatures and concentration of biocides). The fouling community at the offshore intake well comprised of green mussels (Perna viridis) with a loading of 11.1 kg m2 y-1. Fouling load in the pump chamber (suction end) was found to be 8.7 kg m2 y-2, whereas the load in the discharge conduit of the pumps was 4.1 kg m2 y-2. From the pump house the water is pumped through circular concrete conduits (9.9 kg m2 y-2) to the main condensers. Before reaching the main condensers the water passes through a valve pit comprising of circular mild steel sections (7.6 kg m2 y-2). The main condenser inlet water box was relatively less fouled and was found to be dominated by the barnacle B. reticulatus with a load of 1.0 kg m2 y-2. Compared to the main condenser section, the load in concrete conduits feeding the process water heat exchangers was marginally less (8.3 kg m2 y-2) with barnacle Megabalanus tintinnabulum recorded in addition to those observed in the main condenser conduits. The loads in the mild steel pipe sections (after bromide dosing) were about 8.5 kg m2 y-2, indicating the inadequacy of the biocide in combating fouling. From this point the water passes through a rectangular concrete conduit (header) before entering the

  20. Water chemistry and corrosion control of cladding and primary circuit components. Proceedings of a technical committee meeting

    International Nuclear Information System (INIS)

    Corrosion is the principal life limiting degradation mechanism in nuclear steam supply systems, especially taking into account the trends to increase fuel burnup, thermal rate and cycle length. Primary circuit components of water cooled power reactors have an impact on Zr-based alloys behaviour due to crud (primary circuit corrosion products) formation, transport and deposition on heat transfer surfaces. Crud deposits influence water chemistry, radiation and thermal hydraulic conditions near cladding surface, and by this way-Zr-based alloy corrosion. During the last decade, significant improvements were achieved in the reduction of the corrosion and dose rates by changing the cladding material for one more resistant to corrosion or by the improvement of water chemistry conditions. However, taking into account the above mentioned tendency for heavier fuel duties, corrosion and water chemistry, control will remain a serious task to work with for nuclear power plant operators and scientists, as well as development of generally accepted corrosion model of Zr-based alloys in a water environment in a new millennium. Upon the recommendation of the International Working Group on Water Reactor Fuel Performance and Technology, water chemistry and corrosion of cladding and primary circuit components are in the focus of the IAEA activities in the area of fuel technology and performance. At present the IAEA performs two co-ordinated research projects (CRPs): on On-line High Temperature Monitoring of Water Chemistry and Corrosion (WACOL) and on Activity Transport in Primary Circuits. Two CRPs deal with hydrogen and hydride degradation of the Zr-based alloys. A state-of-the-art review entitled: 'Waterside Corrosion of Zirconium Alloys in Nuclear Power Plants' was published in 1998. Technical Committee meetings on the subject were held in 1985 (Cadarache, France), 1989 (Portland, USA), 1993 (Rez, Czech Republic). During the last few years extensive exchange of experience in

  1. Nonlinear feedback control of a novel hyperchaotic system and its circuit implementation

    International Nuclear Information System (INIS)

    This paper reports a new hyperchaotic system by adding an additional state variable into a three-dimensional chaotic dynamical system. Some of its basic dynamical properties, such as the hyperchaotic attractor, Lyapunov exponents, bifurcation diagram and the hyperchaotic attractor evolving into periodic, quasi-periodic dynamical behaviours by varying parameter k are studied. An effective nonlinear feedback control method is used to suppress hyperchaos to unstable equilibrium. Furthermore, a circuit is designed to realize this new hyperchaotic system by electronic workbench (EWB). Numerical simulations are presented to show these results

  2. Reliability assessment of power plant instrumentation and control systems with monolithic integrated circuits

    International Nuclear Information System (INIS)

    The application of present generation of digital and analog monolithic integrated circuits (ICs) to operating nuclear power plant systems has resulted in components scaled down to less than 1/10th of the area of conventional components, and still function faster and more efficiently. Microprocessors and digital/analog ICs in monitoring and control systems have emerged as the preferred choice for power plant systems. This paper develops a reliability analysis for power plant systems with IC components assuming constant failure rate. A variable failure rate model is also developed for analyzing observed failure data to ascertain probable cause

  3. A Nanostructured Composites Thermal Switch Controls Internal and External Short Circuit in Lithium Ion Batteries

    Science.gov (United States)

    McDonald, Robert C.; VanBlarcom, Shelly L.; Kwasnik, Katherine E.

    2013-01-01

    A document discusses a thin layer of composite material, made from nano scale particles of nickel and Teflon, placed within a battery cell as a layer within the anode and/or the cathode. There it conducts electrons at room temperature, then switches to an insulator at an elevated temperature to prevent thermal runaway caused by internal short circuits. The material layer controls excess currents from metal-to-metal or metal-to-carbon shorts that might result from cell crush or a manufacturing defect

  4. Synchronising chaotic Chua's circuit using switching feedback control based on piecewise quadratic Lyapunov functions

    International Nuclear Information System (INIS)

    This paper investigates the chaos synchronisation between two coupled chaotic Chua's circuits. The sufficient condition presented by linear matrix inequalities (LMIs) of global asymptotic synchronisation is attained based on piecewise quadratic Lyapunov functions. First, we obtain the piecewise linear differential inclusions (pwLDIs) model of synchronisation error dynamics, then we design a switching (piecewise-linear) feedback control law to stabilise it based on the piecewise quadratic Laypunov functions. Then we give some numerical simulations to demonstrate the effectiveness of our theoretical results

  5. Analysis and Simple Circuit Design of Double Differential EMG Active Electrode.

    Science.gov (United States)

    Guerrero, Federico Nicolás; Spinelli, Enrique Mario; Haberman, Marcelo Alejandro

    2016-06-01

    In this paper we present an analysis of the voltage amplifier needed for double differential (DD) sEMG measurements and a novel, very simple circuit for implementing DD active electrodes. The three-input amplifier that standalone DD active electrodes require is inherently different from a differential amplifier, and general knowledge about its design is scarce in the literature. First, the figures of merit of the amplifier are defined through a decomposition of its input signal into three orthogonal modes. This analysis reveals a mode containing EMG crosstalk components that the DD electrode should reject. Then, the effect of finite input impedance is analyzed. Because there are three terminals, minimum bounds for interference rejection ratios due to electrode and input impedance unbalances with two degrees of freedom are obtained. Finally, a novel circuit design is presented, including only a quadruple operational amplifier and a few passive components. This design is nearly as simple as the branched electrode and much simpler than the three instrumentation amplifier design, while providing robust EMG crosstalk rejection and better input impedance using unity gain buffers for each electrode input. The interference rejection limits of this input stage are analyzed. An easily replicable implementation of the proposed circuit is described, together with a parameter design guideline to adjust it to specific needs. The electrode is compared with the established alternatives, and sample sEMG signals are obtained, acquired on different body locations with dry contacts, successfully rejecting interference sources. PMID:26841414

  6. Modeling suggests that gene circuit architecture controls phenotypic variability in a bacterial persistence network

    Directory of Open Access Journals (Sweden)

    Koh Rachel S

    2012-05-01

    Full Text Available Abstract Background Bacterial persistence is a non-inherited bet-hedging mechanism where a subpopulation of cells enters a dormant state, allowing those cells to survive environmental stress such as treatment with antibiotics. Persister cells are not mutants; they are formed by natural stochastic variation in gene expression. Understanding how regulatory architecture influences the level of phenotypic variability can help us explain how the frequency of persistence events can be tuned. Results We present a model of the regulatory network controlling the HipBA toxin-antitoxin system from Escherichia coli. Using a biologically realistic model we first determine that the persistence phenotype is not the result of bistability within the network. Next, we develop a stochastic model and show that cells can enter persistence due to random fluctuations in transcription, translation, degradation, and complex formation. We then examine alternative gene circuit architectures for controlling hipBA expression and show that networks with more noise (more persisters and less noise (fewer persisters are straightforward to achieve. Thus, we propose that the gene circuit architecture can be used to tune the frequency of persistence, a trait that can be selected for by evolution. Conclusions We develop deterministic and stochastic models describing how the regulation of toxin and antitoxin expression influences phenotypic variation within a population. Persistence events are the result of stochastic fluctuations in toxin levels that cross a threshold, and their frequency is controlled by the regulatory topology governing gene expression.

  7. Software-Controlled Next Generation Optical Circuit Switching for HPC and Cloud Computing Datacenters

    Directory of Open Access Journals (Sweden)

    Muhammad Imran

    2015-11-01

    Full Text Available In this paper, we consider the performance of optical circuit switching (OCS systems designed for data center networks by using network-level simulation. Recent proposals have used OCS in data center networks but the relatively slow switching times of OCS-MEMS switches (10–100 ms and the latencies of control planes in these approaches have limited their use to the largest data center networks with workloads that last several seconds. Herein, we extend the applicability and generality of these studies by considering dynamically changing short-lived circuits in software-controlled OCS switches, using the faster switching technologies that are now available. The modelled switch architecture features fast optical switches in a single hop topology with a centralized, software-defined optical control plane. We model different workloads with various traffic aggregation parameters to investigate the performance of such designs across usage patterns. Our results show that, with suitable choices for the OCS system parameters, delay performance comparable to that of electrical data center networks can be obtained.

  8. Frequency translating phase conjugation circuit for active retrodirective antenna array. [microwave transmission

    Science.gov (United States)

    Chernoff, R. (Inventor)

    1980-01-01

    An active retrodirective antenna array which has central phasing from a reference antenna element through a "tree" structured network of transmission lines utilizes a number of phase conjugate circuits (PCCs) at each node and a phase reference regeneration circuit (PRR) at each node except the initial node. Each node virtually coincides with an element of the array. A PCC generates the exact conjugate phase of an incident signal using a phase locked loop which combines the phases in an up converter, divides the sum by 2 and mixes the result with the phase in a down converter for phase detection. The PRR extracts the phase from the conjugate phase. Both the PCC and the PRR are not only exact but also free from mixer degeneracy.

  9. 有源忆阻器伏安关系与有源忆阻电路频率特性研究%Voltage-Current Relationship of Active Memristor and Frequency Characteristic of Active Memristive Circuit

    Institute of Scientific and Technical Information of China (English)

    包伯成; 邹相; 胡文; 武花干

    2013-01-01

    Memristor, a nonlinear resistor with memory property, is the fourth basic two-terminal circuit element realized physically recently. In this paper,an active flux-controlled memristor with piecewise-quadratic nonlinearity is taken as an example, upon which voltage-current relationship of the active memristor is analyzed,and frequency response characteristic of a series circuit consisting of an active flux-controlled memristor and a capacitor (simplified by active WC circuit)is studied. The comparison analysis between active WC circuit and active RC circuit is performed. The results indicate that voltage-current characteristics of the active memristor exhibit pinched hysteresis loops and depend on the inner initial states;both active WC circuit and active RC circuit show high pass properties,but the former is a lead network and the latter is a lag network. Circuit simulations are performed based on e-quivalent circuit of active flux-controlled memristor, which well verify theoretical analysis results.%忆阻器是具有记忆特性的非线性电阻器,是物理上新实现的第四种基本二端电路元件.以分段二次型非线性函数描述的有源磁控忆阻器为例,分析了有源忆阻器的伏安关系,研究了有源忆阻器与电容串联电路(简称有源WC电路)的频率响应特性,并与有源RC电路进行了比较分析.结果表明:有源忆阻器的伏安特性曲线为紧磁滞回线,且依赖于其内部初始状态;有源WC电路与有源RC电路均呈现高通特性,但前者为超前网络而后者为滞后网络.基于有源磁控忆阻器的等效电路进行了电路仿真,其结果很好地验证了理论分析结果.

  10. Development of a two-dimensional skin friction balance nulling circuit using multivariable control theory

    Science.gov (United States)

    Tripp, John S.; Patek, Stephen D.

    1988-01-01

    Measurement of planar skin friction forces in aerodynamic testing currently requires installation of two perpendicularly mounted, single-axis balances; consequently, force components must be sensed at two distinct locations. A two-axis instrument developed at the Langley Research Center to overcome this disadvantage allows measurement of a two-dimensional force at one location. This paper describes a feedback-controlled nulling circuit developed for the NASA two-axis balance which, without external compensation, is inherently unstable because of its low friction mechanical design. Linear multivariable control theory is applied to an experimentally validated mathematical model of the balance to synthesize a state-variable feedback control law. Pole placement techniques and computer simulation studies are employed to select eigenvalues which provide ideal transient response with decoupled sensing dynamics.

  11. DNA-based control of protein activity.

    Science.gov (United States)

    Engelen, W; Janssen, B M G; Merkx, M

    2016-03-01

    DNA has emerged as a highly versatile construction material for nanometer-sized structures and sophisticated molecular machines and circuits. The successful application of nucleic acid based systems greatly relies on their ability to autonomously sense and act on their environment. In this feature article, the development of DNA-based strategies to dynamically control protein activity via oligonucleotide triggers is discussed. Depending on the desired application, protein activity can be controlled by directly conjugating them to an oligonucleotide handle, or expressing them as a fusion protein with DNA binding motifs. To control proteins without modifying them chemically or genetically, multivalent ligands and aptamers that reversibly inhibit their function provide valuable tools to regulate proteins in a noncovalent manner. The goal of this feature article is to give an overview of strategies developed to control protein activity via oligonucleotide-based triggers, as well as hurdles yet to be taken to obtain fully autonomous systems that interrogate, process and act on their environments by means of DNA-based protein control. PMID:26812623

  12. Improved resistive shunt by means of negative capacitance: new circuit, performances and multi-mode control

    Science.gov (United States)

    Berardengo, M.; Thomas, O.; Giraud-Audine, C.; Manzoni, S.

    2016-07-01

    This paper deals with vibration control by means of piezoelectric patches shunted with electrical impedances made up by a resistance and a negative capacitance. The paper analyses most of the possible layouts by which a negative capacitance can be built and shows that a common mathematical description is possible. This allows closed formulations to be found in order to optimise the electrical network for mono- and multi-mode control. General analytical formulations are obtained to estimate the performance of the shunt in terms of vibration reduction. In particular, it is highlighted that the main effect of a negative capacitance is to artificially enhance the electromechanical coupling factor, which is the basis of performance estimation. Stability issues relating to the use of negative capacitances are especially addressed using refined models for the piezoelectric patch capacitance. Furthermore, a new circuit based on a couple of negative capacitances is proposed and tested, showing better performances than those provided by the usual layouts with a single negative capacitance. Finally, guidelines and analytical formulations to deal with the practical implementation of negative capacitance circuits are provided.

  13. Evaluation of Heat Removal from RBMK-1500 Core Using Control Rods Cooling Circuit

    Directory of Open Access Journals (Sweden)

    M. Vaisnoras

    2008-05-01

    Full Text Available The Ignalina nuclear power plant is a twin unit with two RBMK-1500, graphite moderated, boiling water, multichannel reactors. After the decision was made to decommission the Ignalina NPP, Unit 1 was shut down on December 31, 2004, and Unit 2 is to be operated until the end of 2009. Despite of this fact, severe accident management guidelines for RBMK-1500 reactor at Ignalina NPP are prepared. In case of beyond design basis accidents, it can occur that no water sources are available at the moment for heat removal from fuel channels. Specificity of RBMK reactor is such that the channels with control rods are cooled with water supplied by the system totally independent from the reactor cooling system. Therefore, the heat removal from RBMK-1500 reactor core using circuit for cooling of rods in control and protection system can be used as nonregular mean for reactor cooldown in case of BDBA. The heat from fuel channels, where heat is generated, through graphite bricks is transferred in radial direction to cooled CPS channels. This article presents the analysis of possibility to remove heat from reactor core in case of large LOCA by employing CPS channels cooling circuit. The analysis was performed for Ignalina NPP with RBMK-1500 reactor using RELAP5-3D and RELAP5 codes. Results of the analysis have shown that, in spite of high thermal inertia of graphite, this heat removal from CPS channels allows to slow down effectively the core heat-up process.

  14. Closed-circuit television and remote crane control for vitrification facilities

    International Nuclear Information System (INIS)

    The Defense Waste Processing Facility is currently under construction at the Savannah River Plant. Within the main process cell (MPC), a 117-ton capacity bridge crane is to be installed to facilitate remote handling and processing operations. E. I. du Pont de Nemours and Company defined and PRC designed and built an operational prototype closed-circuit television (CCTV) and remote control system. Phase I of the program developed the CCTV system to prove the feasibility of a remote viewing system. The phase II program added full crane functional remote control and installed it on an existing hot canyon crane. This prototype system established the criteria for the development of the MPC crane and future crane systems. Parameters were: (a) failsafe assurance, (b) high liability, (c) ease of maintenance for dressed-out personnel, (d) rapid malfunction diagnosis, (e) ergonomics, (f) known picture orientation, and (g) audio system to monitor operational sounds. The complete system has undergone a total demonstration of its operational capabilities using simulator circuits for crane functions and is now being integrated with the crane for a full operational demonstration. The system will then be mothballed pending installation by construction personnel ready for cold startup of the plant in 1988

  15. Thermal research of infrared sight thermoelectric cooler control circuit under temperature environment

    Science.gov (United States)

    Gao, Youtang; Ding, Huan; Xue, Xiao; Xu, Yuan; Chang, Benkang

    2010-10-01

    Testing device TST-05B, which is suitable for adaptability test of semiconductor devices, electronic products and other military equipment under the condition of the surrounding air temperature rapidly changing, is used here for temperature shock test.Thermal stability technology of thermoelectric cooler control circuit infrared sight under temperature shock is studied in this paper. Model parameters and geometry is configured for ADI devices (ADN8830), welding material and PCB which are used in system. Thermoelectric cooler control circuit packaged by CSP32 distribution are simulated and analyzed by thermal shock and waveform through engineering finite element analysis software ANSYYS. Because solders of the whole model have much stronger stress along X direction than that of other directions, initial stress constraints along X direction are primarily considered when the partial model of single solder is imposed by thermal load. When absolute thermal loads stresses of diagonal nodes with maximum strains are separated from the whole model, interpolation is processed according to thermal loads circulation. Plastic strains and thermal stresses of nodes in both sides of partial model are obtained. The analysis results indicates that with thermal load circulation, maximum forces of each circulation along X direction are increasingly enlarged and with the accumulation of plastic strains of danger point, at the same time structural deformation and the location of maximum equivalent plastic strain in the solder joints at the first and eighth, the composition will become invalid in the end.

  16. The Gain Stability and Output Signal-to-noise Ratio Analysis of the Negative Feedback Control in Genetic Circuits

    OpenAIRE

    Liu, S; Chen, C.

    2012-01-01

    Negative feedback genetic circuits (NFGC) are key regulatory motif of cellular robustness with the capability of reducing noise in genetic interaction network. NFGC have the same control theory frame as negative feedback amplifier circuits (NFAC). NFAC can enhance gain stability and output signal-to-noise ratio (OSNR) of output signal (voltage). Whether NFGC possess these two advantages or not is still unclear. We have investigated the advantages of NFGC through using feedback depth analysis ...

  17. Efficiency in Controlling Activities

    OpenAIRE

    Van Nguyen, Tuyen

    2015-01-01

    Controlling is essential for financial success of corporations. An efficient controlling system should be implemented in order to manage financial performance from income, expense to profitability. The purpose of the thesis is to provide insight knowledge towards corporate accounting management as well as to propose potential improvement for the existing controlling system of the case company, which is Bosch Rexroth Japan. The theoretical framework creates the knowledge foundation for re...

  18. OPEN-LOOP CONTROL OF A BIPOLAR STEPPER MOTORS USING THE SPECIALIZED INTEGRATED CIRCUITS

    Directory of Open Access Journals (Sweden)

    Gheorghe BALUTA

    2004-12-01

    Full Text Available This paper describes the open-loop control of a stepper motors. Bipolar stepper motors can be driven with an L297, an L298N bridge driver and very few external components. With an L298N this configuration drives motors with winding currents up to 2.5A. If very high powers are required an equivalent circuit made with discrete transistors replaces the bridge driver. Together these two chips form a complete microprocessor-to-stepper motor interface. The command signals for the controller L297 are generated through an IBM-PC486 interface. It was developed an open-loop command program written in BorlandC programming language.

  19. Instruments used to measure or check {alpha}, {beta}, {gamma} activity and neutron emission in the course of processing ore or irradiated fuel; Appareils de mesure ou de controle {alpha}, {beta}, {gamma}, n, des circuits des usines de traitement du minerai ou du combustible irradie

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, A.; Brunet, M.; Kermagoret, M.; Labeyrie, J.; Roux, G.; Vasseur, J.; Weil, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-07-01

    One of the methods checking ores in the course of treatment is the rapid quantitative determination of thorium. This measurement is carried out by means of a scintillation instrument which shows the {beta} and {alpha} coincidences of ThC and ThC'. The treatment of irradiated fuel is accompanied by a large number of radioactive checks relative to the performance of the fixation and elution operations of uranium in the ion exchangers, to the concentration of radioactivity of effluent sent from the plant into watercourses. The operations of fixation and elution of the uranium are checked automatically by an instrument which takes a sample of 5 cm{sup 3} of solution, evaporates it and measures its activity every 10 or 20 minutes. Plutonium concentrations are measured: - in the presence of strong {beta} {gamma} activities, by means of rotating cylinder detectors; - in the presence of weak {beta} {gamma} activities, by means of {alpha} detectors scanning a constant level liquid surface; - by means of fission chambers relatively insensitive to {gamma}. Fission product concentrations are measured by chambers, counters or scintillators, according to the amount of {gamma} activity present. Finally, the activity of effluent to be emptied into watercourses is checked by means of a scintillation instrument, which measures the {alpha} activity on the one hand, and on the other hand the {beta} {gamma} activity of residue from a 100 cm{sup 3} sample taken and evaporated in 20 minutes. (author) [French] Parmi les controles relatifs au minerai en cours de traitement, figure le dosage rapide de thorium. Cette mesure est realisee au moyen d'un appareillage a scintillation qui met en evidence la coincidence des emissions {beta} et {alpha} du ThC et du ThC'. Le traitement des combustibles irradies s'accompagne d'un grand nombre de controles radioactifs portant sur le fonctionnement des operations de fixation et d'elution de l'uranium dans les

  20. Addiction: Decreased reward sensitivity and increased expectation sensitivity conspire to overwhelm the brain’s control circuit

    Energy Technology Data Exchange (ETDEWEB)

    Volkow, N.D.; Wang, G.; Volkow, N.D.; Wang, G.-J.; Fowler, J.S.; Tomasi, D.; Telang, F.; Baler, R.

    2010-07-01

    Based on brain imaging findings, we present a model according to which addiction emerges as an imbalance in the information processing and integration among various brain circuits and functions. The dysfunctions reflect (a) decreased sensitivity of reward circuits, (b) enhanced sensitivity of memory circuits to conditioned expectations to drugs and drug cues, stress reactivity, and (c) negative mood, and a weakened control circuit. Although initial experimentation with a drug of abuse is largely a voluntary behavior, continued drug use can eventually impair neuronal circuits in the brain that are involved in free will, turning drug use into an automatic compulsive behavior. The ability of addictive drugs to co-opt neurotransmitter signals between neurons (including dopamine, glutamate, and GABA) modifies the function of different neuronal circuits, which begin to falter at different stages of an addiction trajectory. Upon exposure to the drug, drug cues or stress this results in unrestrained hyperactivation of the motivation/drive circuit that results in the compulsive drug intake that characterizes addiction.

  1. Practical aspects of 13C surface receive coils with active decoupling and tuning circuit

    DEFF Research Database (Denmark)

    Nilsson, Daniel; Mohr, Johan Jacob; Zhurbenko, Vitaliy

    2012-01-01

    Magnetic Resonance Imaging (MRI) of nuclei other than 1H (e.g. 13C) allows for characterisation of metabolic processes. Imaging of such nuclei, however, requires development of sensitive MRI coils. This paper describes the design of surface receive coils for 13C imaging in small animals. The design...... is based on application-specified coil profile and includes impedance matching and balancing circuits. Active decoupling is implemented in order to minimize the influence of the receiving coil on the homogeneity of the transmit-coil field. Measurement results for a coil prototype are presented...

  2. Active control of convection

    Energy Technology Data Exchange (ETDEWEB)

    Bau, H.H. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1995-12-31

    Using stability theory, numerical simulations, and in some instances experiments, it is demonstrated that the critical Rayleigh number for the bifurcation (1) from the no-motion (conduction) state to the motion state and (2) from time-independent convection to time-dependent, oscillatory convection in the thermal convection loop and Rayleigh-Benard problems can be significantly increased or decreased. This is accomplished through the use of a feedback controller effectuating small perturbations in the boundary data. The controller consists of sensors which detect deviations in the fluid`s temperature from the motionless, conductive values and then direct actuators to respond to these deviations in such a way as to suppress the naturally occurring flow instabilities. Actuators which modify the boundary`s temperature/heat flux are considered. The feedback controller can also be used to control flow patterns and generate complex dynamic behavior at relatively low Rayleigh numbers.

  3. Active Combustion Control Valve Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the past decade, research into active combustion control has yielded impressive results in suppressing thermoacoustic instabilities and widening the...

  4. Development of Microcontroller-Based Inverter Control Circuit for Residential Wind Generator Application

    Directory of Open Access Journals (Sweden)

    Ahmad Firdaus Ahmad Zaidi

    2011-09-01

    Full Text Available The current usage level of wind power as alternative source of energy in Malaysia is very low. Ironically, some areas particularly coastal area has steady wind energy supply that is potential to generate electricity for residential use. There is urgent need to locally develop the low cost wind turbine generator that has the capability to not only supply electricity to respective household but can be connected to power grid so that excess power could be sold back to the local utility company. Recent developments of power electronic converters allow stable supply needed for grid transfer in respect to nature of wind dynamics, enhanced power extraction and low total harmonic distortion (THD. In this project, an inverter circuit with suitable control scheme design is developed to be used with a 500W permanent magnet type wind generator which is typical for residential use. Expected circuit output is single phase 240V sine wave voltage which is nominal grid voltage with the total harmonics distortion (THD of voltage across load should not exceed 5% as recommended by IEEE Standard 519-1992. The simulation and experimental results are included in the paper.

  5. WindoWorks: A flexible program for computerized testing of accelerator control system electronic circuit boards

    International Nuclear Information System (INIS)

    Since most accelerator control system circuit boards reside in a commercial bus architecture, such as CAMAC or VMEbus, a computerized test station is needed for exercising the boards. This test station is needed for the development of newly designed prototypes, for commissioning newly manufactured boards, for diagnosing boards which have failed in service, and for long term testing of boards with intermittent failure problems. WindoWorks was created to address these needs. It is a flexible program which runs on a PC compatible computer and uses a PC to bus crate interface. WindoWorks was designed to give the user a flexible way to test circuit boards. Each test is incapsulated into a window. By bringing up several different windows the user can run several different tests simultaneously. The windows are sizable, and moveable. They have data entry boxes so that the test can be customized to the users preference. The windows can be used in conjunction with each other in order to create supertests. There are several windows which are generic. They can be used to test basic functions on any VME (or CAMAC) board. There are other windows which have been created to test specific boards. New windows for testing specific boards can be easily created by a Pascal programmer using the WindoWorks framework

  6. Gallium arsenide digital integrated circuits for controlling SLAC CW-RF systems

    International Nuclear Information System (INIS)

    In order to fill the PEP and SPEAR storage rings with beams from the SLC linac and damping rings, precise control of the linac subharmonic buncher and the damping ring RF is required. Recently several companies have developed resettable GaAs master/slave D-type flip-flops which are capable of operating at frequencies of 3 GHz and higher. Using these digital devices as frequency dividers, one can phase shift the SLAC CW-RF systems to optimize the timing for filling the storage rings. We have evaluated the performance of integrated circuits from two vendors for our particular application. Using microstrip circuit techniques, we have built and operated in the accelerator several chassis to synchronize a reset signal from the storage rings to the SLAC 2.856 GHz RF and to phase shift divide-by-four and divide-by-sixteen frequency dividers to the nearest 350 psec bucket required for filling. 4 refs., 4 figs., 2 tabs

  7. Fidelity of frequency and phase entrainment of circuit-level spike activity during DBS.

    Science.gov (United States)

    Agnesi, Filippo; Muralidharan, Abirami; Baker, Kenneth B; Vitek, Jerrold L; Johnson, Matthew D

    2015-08-01

    High-frequency stimulation is known to entrain spike activity downstream and upstream of several clinical deep brain stimulation (DBS) targets, including the cerebellar-receiving area of thalamus (VPLo), subthalamic nucleus (STN), and globus pallidus (GP). Less understood are the fidelity of entrainment to each stimulus pulse, whether entrainment patterns are stationary over time, and how responses differ among DBS targets. In this study, three rhesus macaques were implanted with a single DBS lead in VPLo, STN, or GP. Single-unit spike activity was recorded in the resting state in motor cortex during VPLo DBS, in GP during STN DBS, and in STN and pallidal-receiving area of motor thalamus (VLo) during GP DBS. VPLo DBS induced time-locked spike activity in 25% (n = 15/61) of motor cortex cells, with entrained cells following 7.5 ± 7.4% of delivered pulses. STN DBS entrained spike activity in 26% (n = 8/27) of GP cells, which yielded time-locked spike activity for 8.7 ± 8.4% of stimulus pulses. GP DBS entrained 67% (n = 14/21) of STN cells and 32% (n = 19/59) of VLo cells, which showed a higher fraction of pulses effectively inhibiting spike activity (82.0 ± 9.6% and 86.1 ± 16.6%, respectively). Latency of phase-locked spike activity increased over time in motor cortex (58%, VPLo DBS) and to a lesser extent in GP (25%, STN DBS). In contrast, the initial inhibitory phase observed in VLo and STN during GP DBS remained stable following stimulation onset. Together, these data suggest that circuit-level entrainment is low-pass filtered during high-frequency stimulation, most notably for glutamatergic pathways. Moreover, phase entrainment is not stationary or consistent at the circuit level for all DBS targets. PMID:26084905

  8. Peculiarities of dynamics of the global electric circuit elements during very low solar activity

    International Nuclear Information System (INIS)

    Complete text of publication follows. Accumulated data about dynamics of various elements of the solar - terrestrial relationship allow us to approach the problem of the solar activity influence on the middle atmosphere with taking into account role of the ground surface electrical conductivity. A special importance of this problem appears in the 23 cycle of the solar activity (2006-2009 years). This period is characterized by unusually low values of solar UV radiation as well as of magnitudes of the solar wind magnetic field. It means that impact of the solar electromagnetic energy on the near - Earth space is much weaker than usually. The Earth global electric circuit which includes the ionosphere, the stratosphere and the ground surface as its vital components has its own specific features during considered period. In this paper we outline these peculiarities of the global electric circuit and its influence on the middle atmosphere. First of all, we will demonstrate that experimental values of the atmospheric electric field (observations at Vostok Station, Antarctica) are the lowest during the last 3 years. We claim that role of the electric conductivity of the ground surface begin to play more significant role in the dynamics of the global electric circuit. To confirm that suggestion we studied interaction between the stratospheric temperature distribution in the high latitudes in winters of 2008 - 2009 and the area of the old sea ice (pack ice) in the Arctic Ocean during the same period. We will show that the areas of the low temperatures in the polar stratosphere correspond pretty well to distribution of the pack ice in the Arctic. Our explanation of the phenomena is based on difference of electric conductivity of the ice and of the open ocean water.

  9. Four-quadrant speed control circuit of DC servo motor using integrated voltage control method; Den`atsu sekibunchi seigyo wo mochoiita chokuryu dendoki no shishogen sokudo seigyo

    Energy Technology Data Exchange (ETDEWEB)

    Okui, H. [Osaka polytechnic College, Osaka (Japan); Irie, H. [Osaka Electro-Communication Univ., Osaka (Japan)

    1996-08-20

    The Two-Quadrant chopper is constructed by using smoothing reactor in common of the step-down chopper and step-up chopper of the DC chopper. Furthermore, since the circuit connected in bridge type by using these two groups has both of positive and negative voltage from DC source and can supplies the current from positive and negative directions for load, it is called in general as the Four-Quadrant chopper. As the Four-Quadrant chopper may supply and regenerate power, it works as power amplifier with high efficiency. In this paper, the speed control circuit of DC servo motor using Four-Quadrant integrated voltage control circuit is described. The speed control circuit is composed of simple circuits of one adder integrator and four hysteresis comparators. The Four-Quadrant speed control circuit has a DC motor speed feedback loop and a voltage feedback loop which connects with AC, it plays the Four-Quadrant speed control without current inspection. The speed control characteristics with no steady state error over four quadrants may be obtained, changing of the quadrant is smooth and transition response is rapid. 9 refs., 11 figs.

  10. Active weld control

    Science.gov (United States)

    Powell, Bradley W.; Burroughs, Ivan A.

    1994-01-01

    Through the two phases of this contract, sensors for welding applications and parameter extraction algorithms have been developed. These sensors form the foundation of a weld control system which can provide action weld control through the monitoring of the weld pool and keyhole in a VPPA welding process. Systems of this type offer the potential of quality enhancement and cost reduction (minimization of rework on faulty welds) for high-integrity welding applications. Sensors for preweld and postweld inspection, weld pool monitoring, keyhole/weld wire entry monitoring, and seam tracking were developed. Algorithms for signal extraction were also developed and analyzed to determine their application to an adaptive weld control system. The following sections discuss findings for each of the three sensors developed under this contract: (1) weld profiling sensor; (2) weld pool sensor; and (3) stereo seam tracker/keyhole imaging sensor. Hardened versions of these sensors were designed and built under this contract. A control system, described later, was developed on a multiprocessing/multitasking operating system for maximum power and flexibility. Documentation for sensor mechanical and electrical design is also included as appendices in this report.

  11. Flexible, low-latency architecture for qubit control and measurement in circuit QED

    Science.gov (United States)

    Vlothuizen, Wouter; Deurloo, D.; Sterke, J. De; Vermeulen, R.; Schouten, R. N.; Dicarlo, Leo

    Increasing qubit numbers in circuit QED requires an extensible architecture for digital waveform generation of qubit control and measurement signals. For quantum error correction, the ability to select from a number of predetermined waveforms based on measurement results will become paramount. We present a room-temperature architecture with very low latency from measurement to waveform output. This modular FPGA-based system can generate both baseband and RF modulated signals using DACs clocked at 1 GHz. A backplane that interconnects several modules allows exchange of (measurement) information between modules and maintains deterministic timing across those modules. We replace the typical line based sequencer used in arbitrary waveform generators by a user programmable processor that treats waveforms and measurements as instructions added to a conventional CPU architecture. This allows for flexible coding of triggering, repetitions, delays and interactions between measurement and signal generation. We acknowledge funding from the Dutch Research Organization (NWO), an ERC Synergy Grant, and European project SCALEQIT.

  12. Controllable high-fidelity quantum state transfer and entanglement generation in circuit QED.

    Science.gov (United States)

    Xu, Peng; Yang, Xu-Chen; Mei, Feng; Xue, Zheng-Yuan

    2016-01-01

    We propose a scheme to realize controllable quantum state transfer and entanglement generation among transmon qubits in the typical circuit QED setup based on adiabatic passage. Through designing the time-dependent driven pulses applied on the transmon qubits, we find that fast quantum sate transfer can be achieved between arbitrary two qubits and quantum entanglement among the qubits also can also be engineered. Furthermore, we numerically analyzed the influence of the decoherence on our scheme with the current experimental accessible systematical parameters. The result shows that our scheme is very robust against both the cavity decay and qubit relaxation, the fidelities of the state transfer and entanglement preparation process could be very high. In addition, our scheme is also shown to be insensitive to the inhomogeneous of qubit-resonator coupling strengths. PMID:26804326

  13. Automaticity or active control

    DEFF Research Database (Denmark)

    Tudoran, Ana Alina; Olsen, Svein Ottar

    This study addresses the quasi-moderating role of habit strength in explaining action loyalty. A model of loyalty behaviour is proposed that extends the traditional satisfaction–intention–action loyalty network. Habit strength is conceptualised as a cognitive construct to refer to the psychologic......, respectively, between intended loyalty and action loyalty. At high levels of habit strength, consumers are more likely to free up cognitive resources and incline the balance from controlled to routine and automatic-like responses....

  14. Exhaust constituent emission factors of printed circuit board pyrolysis processes and its exhaust control

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Hung-Lung, E-mail: hlchiang@mail.cmu.edu.tw [Department of Health Risk Management, China Medical University, Taichung, Taiwan (China); Lin, Kuo-Hsiung [Department of Environmental Engineering and Science, Fooyin University, Kaohsiung, Taiwan (China)

    2014-01-15

    Highlights: • Recycling of waste printed circuit boards is an important issue. • Pyrolysis is an emerging technology for PCB treatment. • Emission factors of VOCs are determined for PCB pyrolysis exhaust. • Iron-Al{sub 2}O{sub 3} catalyst was employed for the exhaust control. -- Abstract: The printed circuit board (PCB) is an important part of electrical and electronic equipment, and its disposal and the recovery of useful materials from waste PCBs (WPCBs) are key issues for waste electrical and electronic equipment. Waste PCB compositions and their pyrolysis characteristics were analyzed in this study. In addition, the volatile organic compound (VOC) exhaust was controlled by an iron-impregnated alumina oxide catalyst. Results indicated that carbon and oxygen were the dominant components (hundreds mg/g) of the raw materials, and other elements such as nitrogen, bromine, and copper were several decades mg/g. Exhaust constituents of CO, H{sub 2}, CH{sub 4}, CO{sub 2}, and NOx, were 60–115, 0.4–4.0, 1.1–10, 30–95, and 0–0.7 mg/g, corresponding to temperatures ranging from 200 to 500 °C. When the pyrolysis temperature was lower than 300 °C, aromatics and paraffins were the major species, contributing 90% of ozone precursor VOCs, and an increase in the pyrolysis temperature corresponded to a decrease in the fraction of aromatic emission factors. Methanol, ethylacetate, acetone, dichloromethane, tetrachloromethane and acrylonitrile were the main species of oxygenated and chlorinated VOCs. The emission factors of some brominated compounds, i.e., bromoform, bromophenol, and dibromophenol, were higher at temperatures over 400 °C. When VOC exhaust was flowed through the bed of Fe-impregnated Al{sub 2}O{sub 3}, the emission of ozone precursor VOCs could be reduced by 70–80%.

  15. Exhaust constituent emission factors of printed circuit board pyrolysis processes and its exhaust control

    International Nuclear Information System (INIS)

    Highlights: • Recycling of waste printed circuit boards is an important issue. • Pyrolysis is an emerging technology for PCB treatment. • Emission factors of VOCs are determined for PCB pyrolysis exhaust. • Iron-Al2O3 catalyst was employed for the exhaust control. -- Abstract: The printed circuit board (PCB) is an important part of electrical and electronic equipment, and its disposal and the recovery of useful materials from waste PCBs (WPCBs) are key issues for waste electrical and electronic equipment. Waste PCB compositions and their pyrolysis characteristics were analyzed in this study. In addition, the volatile organic compound (VOC) exhaust was controlled by an iron-impregnated alumina oxide catalyst. Results indicated that carbon and oxygen were the dominant components (hundreds mg/g) of the raw materials, and other elements such as nitrogen, bromine, and copper were several decades mg/g. Exhaust constituents of CO, H2, CH4, CO2, and NOx, were 60–115, 0.4–4.0, 1.1–10, 30–95, and 0–0.7 mg/g, corresponding to temperatures ranging from 200 to 500 °C. When the pyrolysis temperature was lower than 300 °C, aromatics and paraffins were the major species, contributing 90% of ozone precursor VOCs, and an increase in the pyrolysis temperature corresponded to a decrease in the fraction of aromatic emission factors. Methanol, ethylacetate, acetone, dichloromethane, tetrachloromethane and acrylonitrile were the main species of oxygenated and chlorinated VOCs. The emission factors of some brominated compounds, i.e., bromoform, bromophenol, and dibromophenol, were higher at temperatures over 400 °C. When VOC exhaust was flowed through the bed of Fe-impregnated Al2O3, the emission of ozone precursor VOCs could be reduced by 70–80%

  16. Active Control of Suspension Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper some recent research on active control of very long suspension bridges, is presented. The presentation is based on research work at Aalborg University, Denmark. The active control system is based on movable flaps attached to the bridge girder. Wind load on bridges with or without...... flaps attached to the girder is briefly presented. A simple active control system is discussed. Results from wind tunnel experiments with a bridge section show that flaps can be used effectively to control bridge girder vibrations. Flutter conditions for suspension bridges with and without flaps are...

  17. On the organization of the quality control of the multiple forced circulation circuit metal of the RBMK-1000 reactor

    International Nuclear Information System (INIS)

    The main requirements for organization of the control over the metal of the multiple forced circulation circuit (MFC) of the RBMK-1000 reactor are discussed. The requirements are based on the branch instruction on the operation control of the NPP pipeline and equipment metal corresponding to the main IAEA recommendations. Periodicity and the main types of the controlled equipment as well as evaluation of labour costs for manual control of the metal state of the drum-separator by means of commercial defectoscopic technique are presented. Labour costs make up about 300,000 men-h according to the preliminary data for the total manual control cycle (100% control) of the metal of the RBMK-1000 MFC circuit. A conclusion is made on advisability of a wide-range introduction of mechanized and automated control means

  18. Cellular and circuit models of increased resting-state network gamma activity in schizophrenia.

    Science.gov (United States)

    White, R S; Siegel, S J

    2016-05-01

    Schizophrenia (SCZ) is a disorder characterized by positive symptoms (hallucinations, delusions), negative symptoms (blunted affect, alogia, reduced sociability, and anhedonia), as well as persistent cognitive deficits (memory, concentration, and learning). While the biology underlying subjective experiences is difficult to study, abnormalities in electroencephalographic (EEG) measures offer a means to dissect potential circuit and cellular changes in brain function. EEG is indispensable for studying cerebral information processing due to the introduction of techniques for the decomposition of event-related activity into its frequency components. Specifically, brain activity in the gamma frequency range (30-80Hz) is thought to underlie cognitive function and may be used as an endophenotype to aid in diagnosis and treatment of SCZ. In this review we address evidence indicating that there is increased resting-state gamma power in SCZ. We address how modeling this aspect of the illness in animals may help treatment development as well as providing insights into the etiology of SCZ. PMID:26577758

  19. Musical molecules: the molecular junction as an active component in audio distortion circuits

    International Nuclear Information System (INIS)

    Molecular junctions that have a non-linear current–voltage characteristic consistent with quantum mechanical tunneling are demonstrated as analog audio clipping elements in overdrive circuits widely used in electronic music, particularly with electric guitars. The performance of large-area molecular junctions fabricated at the wafer level is compared to currently standard semiconductor diode clippers, showing a difference in the sound character. The harmonic distributions resulting from the use of traditional and molecular clipping elements are reported and discussed, and differences in performance are noted that result from the underlying physics that controls the electronic properties of each clipping component. In addition, the ability to tune the sound using the molecular junction is demonstrated. Finally, the hybrid circuit is compared to an overdriven tube amplifier, which has been the standard reference electric guitar clipped tone for over 60 years. In order to investigate the feasibility of manufacturing molecular junctions for use in commercial applications, devices are fabricated using a low-density format at the wafer level, where 38 dies per wafer, each containing two molecular junctions, are made with exceptional non-shorted yield (99.4%, representing 718 out of 722 tested devices) without requiring clean room facilities. (paper)

  20. Musical molecules: the molecular junction as an active component in audio distortion circuits

    Science.gov (United States)

    Bergren, Adam Johan; Zeer-Wanklyn, Lucas; Semple, Mitchell; Pekas, Nikola; Szeto, Bryan; McCreery, Richard L.

    2016-03-01

    Molecular junctions that have a non-linear current-voltage characteristic consistent with quantum mechanical tunneling are demonstrated as analog audio clipping elements in overdrive circuits widely used in electronic music, particularly with electric guitars. The performance of large-area molecular junctions fabricated at the wafer level is compared to currently standard semiconductor diode clippers, showing a difference in the sound character. The harmonic distributions resulting from the use of traditional and molecular clipping elements are reported and discussed, and differences in performance are noted that result from the underlying physics that controls the electronic properties of each clipping component. In addition, the ability to tune the sound using the molecular junction is demonstrated. Finally, the hybrid circuit is compared to an overdriven tube amplifier, which has been the standard reference electric guitar clipped tone for over 60 years. In order to investigate the feasibility of manufacturing molecular junctions for use in commercial applications, devices are fabricated using a low-density format at the wafer level, where 38 dies per wafer, each containing two molecular junctions, are made with exceptional non-shorted yield (99.4%, representing 718 out of 722 tested devices) without requiring clean room facilities.

  1. Plasticity in the brainstem vagal circuits controlling gastric motor function triggered by corticotropin releasing factor.

    Science.gov (United States)

    Browning, Kirsteen N; Babic, Tanja; Toti, Luca; Holmes, Gregory M; Coleman, F Holly; Travagli, R Alberto

    2014-10-15

    Stress impairs gastric emptying, reduces stomach compliance and induces early satiety via vagal actions. We have shown recently that the ability of the anti-stress neuropeptide oxytocin (OXT) to modulate vagal brainstem circuits undergoes short-term plasticity via alterations in cAMP levels subsequent to vagal afferent fibre-dependent activation of metabotropic glutamate receptors. The aim of the present study was to test the hypothesis that the OXT-induced gastric response undergoes plastic changes in the presence of the prototypical stress hormone, corticotropin releasing factor (CRF). Whole cell patch clamp recordings showed that CRF increased inhibitory GABAergic synaptic transmission to identified corpus-projecting dorsal motor nucleus of the vagus (DMV) neurones. In naive brainstem slices, OXT perfusion had no effect on inhibitory synaptic transmission; following exposure to CRF (and recovery from its actions), however, re-application of OXT inhibited GABAergic transmission in the majority of neurones tested. This uncovering of the OXT response was antagonized by pretreatment with protein kinase A or adenylate cyclase inhibitors, H89 and di-deoxyadenosine, respectively, indicating a cAMP-mediated mechanism. In naive animals, OXT microinjection in the dorsal vagal complex induced a NO-mediated corpus relaxation. Following CRF pretreatment, however, microinjection of OXT attenuated or, at times reversed, the gastric relaxation which was insensitive to l-NAME but was antagonized by pretreatment with a VIP antagonist. Immunohistochemical analyses of vagal motoneurones showed an increased number of oxytocin receptors present on GABAergic terminals of CRF-treated or stressed vs. naive rats. These results indicate that CRF alters vagal inhibitory circuits that uncover the ability of OXT to modulate GABAergic currents and modifies the gastric corpus motility response to OXT. PMID:25128570

  2. Synchronic, optical transmission data link integrated with FPGA circuits (for TESLA LLRF control system)

    Energy Technology Data Exchange (ETDEWEB)

    Zielinski, J.S.

    2006-07-15

    The X-ray free-electron laser X-FEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short X-ray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new possibilities for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated to the LLRF1 system in VUV FEL experiment It is being developed by the ELHEP2 group in the Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller to stabilize the vector sum of fields in cavities of one cryo-module in the experiment. The device can be also used as the simulator of the cavity and test bench for other devices. The synchronic, optical link project was made for the accelerator X-FEL laser TESLA, the LLRF control system experiment at DESY, Hamburg. The control and diagnostic data is transmitted up to 2.5Gbit/s through a plastic fiber in a distance up to a few hundred meters. The link is synchronized once after power up, and never resynchronized when data is transmitted with maximum speed. The one way link bit error rate is less then 10{sup -15}. The transceiver component written in VHDL that works in the dedicated Altera registered Stratix registered GX FPGA circuit. During the work in the PERG laboratory a 2,5Gbit/s serial link with the long vector parallel interface transceiver was created. Long-Data-Vector transceiver transmits 16bit vector each 8ns with 120ns latency. (orig.)

  3. Synchronic, optical transmission data link integrated with FPGA circuits (for TESLA LLRF control system)

    International Nuclear Information System (INIS)

    The X-ray free-electron laser X-FEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short X-ray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new possibilities for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated to the LLRF1 system in VUV FEL experiment It is being developed by the ELHEP2 group in the Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller to stabilize the vector sum of fields in cavities of one cryo-module in the experiment. The device can be also used as the simulator of the cavity and test bench for other devices. The synchronic, optical link project was made for the accelerator X-FEL laser TESLA, the LLRF control system experiment at DESY, Hamburg. The control and diagnostic data is transmitted up to 2.5Gbit/s through a plastic fiber in a distance up to a few hundred meters. The link is synchronized once after power up, and never resynchronized when data is transmitted with maximum speed. The one way link bit error rate is less then 10-15. The transceiver component written in VHDL that works in the dedicated Altera registered Stratix registered GX FPGA circuit. During the work in the PERG laboratory a 2,5Gbit/s serial link with the long vector parallel interface transceiver was created. Long-Data-Vector transceiver transmits 16bit vector each 8ns with 120ns latency. (orig.)

  4. A Novel LTPS-TFT Pixel Circuit to Compensate the Electronic Degradation for Active-Matrix Organic Light-Emitting Diode Displays

    OpenAIRE

    Ching-Lin Fan; Fan-Ping Tseng; Hui-Lung Lai; Bo-Jhang Sun; Kuang-Chi Chao; Yi-Chiung Chen

    2013-01-01

    A novel pixel driving circuit for active-matrix organic light-emitting diode (AMOLED) displays with low-temperature polycrystalline-silicon thin-film transistors (LTPS-TFTs) is studied. The proposed compensation pixel circuit is driven by voltage programming scheme, which is composed of five TFTs and one capacitor, and has been certified to provide uniform output current by the Automatic Integrated Circuit Modeling Simulation Program with Integrated Circuit Emphasis (AIM-SPICE) simulator. The...

  5. Temperature control of molecular circuit switch responsible for virulent phenotype expression in uropathogenic Escherichia coli

    Science.gov (United States)

    Samoilov, Michael

    2010-03-01

    The behavior and fate of biological organisms are to a large extent dictated by their environment, which can be often viewed as a collection of features and constraints governed by physics laws. Since biological systems comprise networks of molecular interactions, one such key physical property is temperature, whose variations directly affect the rates of biochemical reactions involved. For instance, temperature is known to control many gene regulatory circuits responsible for pathogenicity in bacteria. One such example is type 1 fimbriae (T1F) -- the foremost virulence factor in uropathogenic E. coli (UPEC), which accounts for 80-90% of all community-acquired urinary tract infections (UTIs). The expression of T1F is randomly `phase variable', i.e. individual cells switch between virulent/fimbriate and avirulent/afimbriate phenotypes, with rates regulated by temperature. Our computational investigation of this process, which is based on FimB/FimE recombinase-mediated inversion of fimS DNA element, offers new insights into its discrete-stochastic kinetics. In particular, it elucidates the logic of T1F control optimization to the host temperature and contributes further understanding toward the development of novel therapeutic approaches to UPEC-caused UTIs.

  6. A Realization of SC-CNN-Based Circuit Using FTFN

    OpenAIRE

    Günay, Enis; UZUNHİSARCIKLI, Esma; KILIÇ, Recai; ALÇI, Mustafa

    2005-01-01

    In this paper, a realization of the State Controlled Cellular Neural Network (SC-CNN)-based circuit using Four Terminal Floating Nullor (FTFN) as active element is presented. In this realization, a new version of autonomous Chua's circuit has been considered using FTFN realization of SC-CNN-based circuit. The performance of the proposed SC-CNN-based circuit is demonstrated by PSpice simulations.

  7. Microwave amplifier and active circuit design using the real frequency technique

    CERN Document Server

    Jarry, Pierre

    2016-01-01

    This book focuses on the authors' Real Frequency Technique (RFT) and its application to a wide variety of multi-stage microwave amplifiers and active filters, and passive equalizers for radar pulse shaping and antenna return loss applications. The first two chapters review the fundamentals of microwave amplifier design and provide a description of the RFT. Each subsequent chapter introduces a new type of amplifier or circuit design, reviews its design problems, and explains how the RFT can be adapted to solve these problems. The authors take a practical approach by summarizing the design steps and giving numerous examples of amplifier realizations and measured responses. Provides a complete description of the RFT as it is first used to design multistage lumped amplifiers using a progressive optimization of the equalizers, leading to a small umber of parameters to optimize simultaneously Presents modifications to the RFT to design trans-impedance microwave amplifiers that are used for photodiodes acti...

  8. Research on a new active power filter topology based on chopper circuit

    CERN Document Server

    Xiaoling, Guo; Bo, Zhang; Jing, Zhang

    2015-01-01

    The active power filter (APF) is attracting more and more attention for its outstanding performance in current and voltage ripple compensation. As modern high-energy accelerators are demanding much more stringent current ripple guideline, the APF is introduced to the magnet power supply (MPS) in accelerator system. However, the conventional APF has a lot of shortages and drawbacks due to its traditional topology, such as complex structure, nonadjustable working voltage, requirement of power supply, and so on. This paper proposes a new topology of APF, which is working as two types of chopper circuits. This APF need not extra electricity, but to use the power of the MPS current ripple to realize ripple depressing. At the end of this paper, the experiment result proves its feasibility and effect.

  9. Compact Hybrid Subsystem of 16 Channel Optical Demultiplexer, 2x2 Switches, Optical Power Monitors and Control Circuit

    Institute of Scientific and Technical Information of China (English)

    Kenichiro; Takahashi; Toshihiko; Kishimoto; Shintaro; Mouri; Youichi; Hata; Hideaki; Yusa; Mitsuaki; Tamura; Kazuhito; Saito; Hisao; Maki

    2003-01-01

    A compact hybrid subsystem of 16channel optical demultiplexer, 2x2 switches, optical power monitors and control circuit board is developed. The subsystem is able to add or drop arbitrary optical channels and monitor the optical power level by software commands. The size of the subsystem is 170x200x30(mm).

  10. 一种应用于AMOLED的阵列扫描控制电路%A Kind of the Array Scanning and Controlling Circuit for AMOLED

    Institute of Scientific and Technical Information of China (English)

    闵剑; 余菲; 梁蓓

    2011-01-01

    In order to increase the yields and decrease the cost, a driving circuit scheme for the active matrix organic light emitting device ( AMOLED ) on panel was proposed. This driving circuit was composed of the array scanning and controlling circuit with PMOS-TFI( P-type Metal Oxide Semiconductor-Thin Film Transistor). Each array scanning and controlling unit was controlled by the two clock signals, and it included five PMOS-TFTs. It was showed that the result of simulation was the same as the result of analysis by using HSPICE, and the correctness of the circuitry was also verified.%为了提高显示屏的成品率,降低成本,提出了AMOLED屏上行驱动电路的一种设计方案,以PMOS-TFT为行驱动电路的结构.该电路由阵列扫描控制电路构成,每个阵列扫描控制单元由2个时钟信号控制,并包含5个PMOS-TFT.通过HSPICE的仿真,结果得出电路的仿真结果与分析结果一致,验证了电路功能的正确性.

  11. Controller with an ispLS1016 circuit for the utilization of a TV fifo in spectrometric

    International Nuclear Information System (INIS)

    It is described the design of a controller based in the integrated circuit ispLS1016 for the utilization of a 256K x 8 FIFO originally for digital video applications in spectroscopy., Co, Zn, Sn, U and Th (deposited in filter paper) are The design was based upon an integrated circuit of the ispLSI family, which allowed drastically to diminish the quantity of utilized components, to obtain a flexible design in less time and to fulfill other specific requirements for spectroscopy applications

  12. Single axis controlled hybrid magnetic bearing for left ventricular assist device: hybrid core and closed magnetic circuit.

    Science.gov (United States)

    da Silva, Isaias; Horikawa, Oswaldo; Cardoso, Jose R; Camargo, Fernando A; Andrade, Aron J P; Bock, Eduardo G P

    2011-05-01

    In previous studies, we presented main strategies for suspending the rotor of a mixed-flow type (centrifugal and axial) ventricular assist device (VAD), originally presented by the Institute Dante Pazzanese of Cardiology (IDPC), Brazil. Magnetic suspension is achieved by the use of a magnetic bearing architecture in which the active control is executed in only one degree of freedom, in the axial direction of the rotor. Remaining degrees of freedom, excepting the rotation, are restricted only by the attraction force between pairs of permanent magnets. This study is part of a joint project in development by IDPC and Escola Politecnica of São Paulo University, Brazil. This article shows advances in that project, presenting two promising solutions for magnetic bearings. One solution uses hybrid cores as electromagnetic actuators, that is, cores that combine iron and permanent magnets. The other solution uses actuators, also of hybrid type, but with the magnetic circuit closed by an iron core. After preliminary analysis, a pump prototype has been developed for each solution and has been tested. For each prototype, a brushless DC motor has been developed as the rotor driver. Each solution was evaluated by in vitro experiments and guidelines are extracted for future improvements. Tests have shown good results and demonstrated that one solution is not isolated from the other. One complements the other for the development of a single-axis-controlled, hybrid-type magnetic bearing for a mixed-flow type VAD. PMID:21595710

  13. A 10-bit 250 MSPS charge-domain pipelined ADC with replica controlled PVT insensitive BCT circuit

    Science.gov (United States)

    Songren, Huang; Hong, Zhang; Zhenhai, Chen; Shuang, Zhu; Zongguang, Yu; Hongwen, Qian; Yue, Hao

    2015-05-01

    A low power 10-bit 250 MSPS charge-domain (CD) pipelined analog-to-digital converter (ADC) is introduced. The ADC is implemented in MOS bucket-brigade devices (BBDs) based CD pipelined architecture. A replica controlled boosted charge transfer (BCT) circuit is introduced to reject the influence of PVT variations on the charge transfer process. Based on replica controlled BCT, the CD pipelined ADC is designed and realized in a 1P6M 0.18 μm CMOS process. The ADC achieves an SFDR of 64.4 dB, an SNDR of 56.9 dB and an ENOB of 9.2 for a 9.9 MHz input; and an SFDR of 63.1 dB, an SNR of 55.2 dB, an SNDR of 54.5 dB and an ENOB of 8.7 for a 220.5 MHz input at full sampling rate. The DNL is +0.5/ -0.55 LSB and INL is +0.8/ -0.85 LSB. The power consumption of the prototype ADC is only 45 mW at 1.8 V supply and it occupies an active die area of 1.56 mm2. Project supported by the National Natural Science Foundation of China (No. 61106027).

  14. Neural Dysfunction in Cognitive Control Circuits in Persons at Clinical High-Risk for Psychosis.

    Science.gov (United States)

    Colibazzi, Tiziano; Horga, Guillermo; Wang, Zhishun; Huo, Yuankai; Corcoran, Cheryl; Klahr, Kristin; Brucato, Gary; Girgis, Ragy; Gill, Kelly; Abi-Dargham, Anissa; Peterson, Bradley S

    2016-04-01

    Cognitive control, a set of functions that develop throughout adolescence, is important in the pathogenesis of psychotic disorders. Whether cognitive control has a role in conferring vulnerability for the development of psychotic illness is still unknown. The aim of this study was to investigate the neural systems supporting cognitive control in individuals deemed to be potentially prodromal for psychotic illness. We recruited 56 participants at clinical high-risk (CHR) for psychosis based on the Structured Interview for Psychosis-Risk Syndromes (SIPS) and 49 healthy controls. Twelve of the CHR participants eventually developed psychosis. We compared functional magnetic resonance imaging (fMRI) BOLD signal during the performance of the Simon task. We tested for differences between CHR individuals and controls in conflict-related functional activity. In the CHR group when compared with controls, we detected smaller conflict-related activations in several cortical areas, including the Dorsolateral Prefrontal Cortex (DLPFC). Furthermore, conflict-related activations in the DLPFC of those CHR individuals who ultimately developed psychosis (CHR converters) were smaller than in non-converters (CHR non-converters). Higher levels of conflict-related activation were associated with better social and role outcome. Risk for psychosis was associated at the neural level with reduced conflict-related brain activity. This neural phenotype appears correlated within the DLPFC with the development of psychosis and with functional outcome. PMID:26354046

  15. A Hybrid Circuit for Spoof Surface Plasmons and Spatial Waveguide Modes to Reach Controllable Band-Pass Filters

    Science.gov (United States)

    Zhang, Qian; Zhang, Hao Chi; Wu, Han; Cui, Tie Jun

    2015-11-01

    We propose a hybrid circuit for spoof surface plasmon polaritons (SPPs) and spatial waveguide modes to develop new microwave devices. The hybrid circuit includes a spoof SPP waveguide made of two anti-symmetric corrugated metallic strips and a traditional substrate integrated waveguide (SIW). From dispersion relations, we show that the electromagnetic waves only can propagate through the hybrid circuit when the operating frequency is less than the cut-off frequency of the SPP waveguide and greater than the cut-off frequency of SIW, generating efficient band-pass filters. We demonstrate that the pass band is controllable in a large range by designing the geometrical parameters of SPP waveguide and SIW. Full-wave simulations are provided to show the large adjustability of filters, including ultra wideband and narrowband filters. We fabricate a sample of the new hybrid device in the microwave frequencies, and measurement results have excellent agreements to numerical simulations, demonstrating excellent filtering characteristics such as low loss, high efficiency, and good square ratio. The proposed hybrid circuit gives important potential to accelerate the development of plasmonic integrated functional devices and circuits in both microwave and terahertz frequencies.

  16. Control of microwave signals using bichromatic electromechanically induced transparency in multimode circuit electromechanical systems

    Science.gov (United States)

    Cheng, Jiang; Yuanshun, Cui; Xintian, Bian; Xiaowei, Li; Guibin, Chen

    2016-05-01

    We theoretically investigate the tunable delay and advancement of microwave signals based on bichromatic electromechanically induced transparency in a three-mode circuit electromechanical system, where two nanomechanical resonators with closely spaced frequencies are independently coupled to a common microwave cavity. In the presence of a strong microwave pump field, we obtain two transparency windows accompanied by steep phase dispersion in the transmitted microwave probe field. The width of the transparency window and the group delay of the probe field can be controlled effectively by the power of the pump field. It is shown that the maximum group delay of 0.12 ms and the advancement of 0.27 ms can be obtained in the current experiments. Project supported by the National Natural Science Foundation of China (Grant Nos. 11304110 and 11174101), the Jiangsu Natural Science Foundation, China (Grant Nos. BK20130413 and BK2011411), and the Natural Science Foundation of Jiangsu Higher Education Institutions of China (Grant Nos. 13KJB140002 and 15KJB460004).

  17. PSPICE controlled-source models of analogous circuit for Langevin type piezoelectric transducer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The design and construction of wide-band and high efficiency acoustical projector has long been considered an art beyond the capabilities of many smaller groups. Langevin type piezoelectric transducers have been the most candidate of sonar array system applied in underwater communication. The transducers are fabricated, by bolting head mass and tail mass on both ends of stacked piezoelectric ceramic, to satisfy the multiple, conflicting design for high power transmitting capability. The aim of this research is to study the characteristics of Langevin type piezoelectric transducer that depend on different metal loading. First, the Mason equivalent circuit is used to model the segmented piezoelectric ceramic, then, the impedance network of tail and head masses is deduced by the Newton’s theory. To obtain the optimal solution to a specific design formulation, PSPICE controlled-source programming techniques can be applied. A valid example of the application of PSPICE models for Langevin type transducer analysis is presented and the simulation results are in good agreement with the experimental measurements.

  18. Voltage control in the stator circuit of cage induction machine operating as generator in small scale hydropower plant

    OpenAIRE

    Kandyba, Andrzej; Kalus, Marian; Kurytnik, Igor Piotr

    2012-01-01

    The synthesis of RMS voltage control system in the stator circuit of squirrel cage induction machine based on the linear criterion of " optimum magnitude" by C. Kessler 'a was performed. The squirrel cage induction machine was operating as a generator in autonomous (isolated) network. Induction machine is driven by an induction machine supplied from the inverter, which simulates the low pressure head water turbine. Synthesis process of the control system was supported by experimental studi...

  19. Temperature control system for the study of single event effects in integrated circuits using a cyclotron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Bakerenkov, A.S., E-mail: as_bakerenkov@list.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Belyakov, V.V. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Kozyukov, A.E. [Joint-Stock Company Institute of Space Device Engineering (JSC ISDE), Moscow (Russian Federation); Pershenkov, V.S.; Solomatin, A.V.; Shurenkov, V.V. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2015-02-11

    The temperature control system for the study of single event disruptions produced by hard ion impacts in integrated circuits is described. Heating and cooling of the irradiated device are achieved using thermoelectric modules (Peltier modules). The thermodynamic performance of the system is estimated. The technique for the numerical estimation of the main parameters of the temperature control system for cooling and heating is considered. The results of a test of the system in a vacuum cell of an accelerator are presented.

  20. Temperature control system for the study of single event effects in integrated circuits using a cyclotron accelerator

    International Nuclear Information System (INIS)

    The temperature control system for the study of single event disruptions produced by hard ion impacts in integrated circuits is described. Heating and cooling of the irradiated device are achieved using thermoelectric modules (Peltier modules). The thermodynamic performance of the system is estimated. The technique for the numerical estimation of the main parameters of the temperature control system for cooling and heating is considered. The results of a test of the system in a vacuum cell of an accelerator are presented

  1. Successful reconstruction of a physiological circuit with known connectivity from spiking activity alone.

    Directory of Open Access Journals (Sweden)

    Felipe Gerhard

    Full Text Available Identifying the structure and dynamics of synaptic interactions between neurons is the first step to understanding neural network dynamics. The presence of synaptic connections is traditionally inferred through the use of targeted stimulation and paired recordings or by post-hoc histology. More recently, causal network inference algorithms have been proposed to deduce connectivity directly from electrophysiological signals, such as extracellularly recorded spiking activity. Usually, these algorithms have not been validated on a neurophysiological data set for which the actual circuitry is known. Recent work has shown that traditional network inference algorithms based on linear models typically fail to identify the correct coupling of a small central pattern generating circuit in the stomatogastric ganglion of the crab Cancer borealis. In this work, we show that point process models of observed spike trains can guide inference of relative connectivity estimates that match the known physiological connectivity of the central pattern generator up to a choice of threshold. We elucidate the necessary steps to derive faithful connectivity estimates from a model that incorporates the spike train nature of the data. We then apply the model to measure changes in the effective connectivity pattern in response to two pharmacological interventions, which affect both intrinsic neural dynamics and synaptic transmission. Our results provide the first successful application of a network inference algorithm to a circuit for which the actual physiological synapses between neurons are known. The point process methodology presented here generalizes well to larger networks and can describe the statistics of neural populations. In general we show that advanced statistical models allow for the characterization of effective network structure, deciphering underlying network dynamics and estimating information-processing capabilities.

  2. Optical control of antibacterial activity

    Science.gov (United States)

    Velema, Willem A.; van der Berg, Jan Pieter; Hansen, Mickel J.; Szymanski, Wiktor; Driessen, Arnold J. M.; Feringa, Ben L.

    2013-11-01

    Bacterial resistance is a major problem in the modern world, stemming in part from the build-up of antibiotics in the environment. Novel molecular approaches that enable an externally triggered increase in antibiotic activity with high spatiotemporal resolution and auto-inactivation are highly desirable. Here we report a responsive, broad-spectrum, antibacterial agent that can be temporally activated with light, whereupon it auto-inactivates on the scale of hours. The use of such a ‘smart’ antibiotic might prevent the build-up of active antimicrobial material in the environment. Reversible optical control over active drug concentration enables us to obtain pharmacodynamic information. Precisely localized control of activity is achieved, allowing the growth of bacteria to be confined to defined patterns, which has potential for the development of treatments that avoid interference with the endogenous microbial population in other parts of the organism.

  3. Dopamine-dependent synaptic plasticity in an amygdala inhibitory circuit controls fear memory expression.

    Science.gov (United States)

    Lee, Joo Han; Kim, Joung-Hun

    2016-01-01

    Of the numerous events that occur in daily life, we readily remember salient information, but do not retain most less-salient events for a prolonged period. Although some of the episodes contain putatively emotional aspects, the information with lower saliency is rarely stored in neural circuits via an unknown mechanism. We provided substantial evidence indicating that synaptic plasticity in the dorsal ITC of amygdala allows for selective storage of salient emotional experiences, while it deters less-salient experience from entering long-term memory. After activation of D4R or weak fear conditioning, STDP stimulation induces LTD in the LA-ITC synapses. This form of LTD is dependent upon presynaptic D4R, and is likely to result from enhancement of GABA release. Both optogenetic abrogation of LTD and ablation of D4R at the dorsal ITC in vivo lead to heightened and over-generalized fear responses. Finally, we demonstrated that LTD was impaired at the dorsal ITC of PTSD model mice, which suggests that maladaptation of GABAergic signaling and the resultant LTD impairment contribute to the endophenotypes of PTSD. PMID:26674344

  4. The circuit designer's companion

    CERN Document Server

    Williams, Tim

    2013-01-01

    The Circuit Designer's Companion covers the theoretical aspects and practices in analogue and digital circuit design. Electronic circuit design involves designing a circuit that will fulfill its specified function and designing the same circuit so that every production model of it will fulfill its specified function, and no other undesired and unspecified function.This book is composed of nine chapters and starts with a review of the concept of grounding, wiring, and printed circuits. The subsequent chapters deal with the passive and active components of circuitry design. These topics are foll

  5. Fractional active disturbance rejection control.

    Science.gov (United States)

    Li, Dazi; Ding, Pan; Gao, Zhiqiang

    2016-05-01

    A fractional active disturbance rejection control (FADRC) scheme is proposed to improve the performance of commensurate linear fractional order systems (FOS) and the robust analysis shows that the controller is also applicable to incommensurate linear FOS control. In FADRC, the traditional extended states observer (ESO) is generalized to a fractional order extended states observer (FESO) by using the fractional calculus, and the tracking differentiator plus nonlinear state error feedback are replaced by a fractional proportional-derivative controller. To simplify controller tuning, the linear bandwidth-parameterization method has been adopted. The impacts of the observer bandwidth ωo and controller bandwidth ωc on system performance are then analyzed. Finally, the FADRC stability and frequency-domain characteristics for linear single-input single-output FOS are analyzed. Simulation results by FADRC and ADRC on typical FOS are compared to demonstrate the superiority and effectiveness of the proposed scheme. PMID:26928516

  6. Active control: Wind turbine model

    DEFF Research Database (Denmark)

    Bindner, H.

    1999-01-01

    This report is a part of the reporting of the work done in the project 'Active Control of Wind Turbines'. This project aim is to develop a simulation model for design of control systems for turbines with pitch control and to use that model to designcontrollers. This report describes the model...... developed for controller design and analysis. Emphasis has been put on establishment of simple models describing the dynamic behavior of the wind turbine in adequate details for controller design. This hasbeen done with extensive use of measurements as the basis for selection of model complexity and model....... The models are all formulated as linear differential equations. The models are validated throughcomparisons with measurements performed on a Vestas WD 34 400 kW wind turbine. It is shown from a control point of view simple linear models can be used to describe the dynamic behavior of a pitch...

  7. CIRCUIT RESISTANCE EXERCISE IMPROVES GLYCEMIC CONTROL AND ADIPOKINES IN FEMALES WITH TYPE 2 DIABETES MELLITUS

    Directory of Open Access Journals (Sweden)

    Nam Hwoeh Yeo

    2009-12-01

    Full Text Available The aim of study was to evaluate whether circuit resistance exercise (CE improves glycemic control and adipokine levels in comparison with walking exercise (WE in 15 adult postmenopausal Korean females with type 2 diabetes mellitus (T2DM. The participants were randomly assigned to either the CE or WE group. Subjects exercised for 1 h, three times per week for 12 weeks. The parameters measured were body composition, respiratory rate, blood glucose, insulin and adipokines. The body composition of the CE group showed a significant reduction (all p < 0.05 in body weight, body mass index (BMI, and percentage of body fat and a significant increase in muscle mass. Respiratory function was also significantly increased in the CE group. Additionally, hemoglobin A1c (HbA1c changed favorably in the CE group, as were the concentrations of adipokines such as retinol binding protein 4 (RBP-4 (p < 0.05, adiponectin (p < 0.01, and monocyte chemoattractant protein-1 (MCP-1 (p < 0.01. In addition, significant correlations with CE were evident for homeostatic model assessment insulin resistance (HOMA-IR and glucose (r = 0.69, p < 0.001, muscle mass and glucose (r = 0.45, p < 0.05, and muscle mass and HbA1c (r = 0.39, p < 0.05. The beneficial effects of CE include the development of muscle mass, which effectively increases glucose use and reduces the amount of insulin required. Thus, our results suggest that CE improves glycemic control and adipokines resulting from incrementally increased muscle mass and reductions of body weight, BMI and percentage of body fat for T2DM postmenopausal Korean women

  8. The Electron Runaround: Understanding Electric Circuit Basics through a Classroom Activity

    Science.gov (United States)

    Singh, Vandana

    2010-01-01

    Several misconceptions abound among college students taking their first general physics course, and to some extent pre-engineering physics students, regarding the physics and applications of electric circuits. Analogies used in textbooks, such as those that liken an electric circuit to a piped closed loop of water driven by a water pump, do not…

  9. ABOUT CONTROLLING OF SCIENTIFIC ACTIVITY

    Directory of Open Access Journals (Sweden)

    Mukhin V. V.

    2014-06-01

    Full Text Available We have selected the new area of controlling - scientific activity controlling. We consider some problems of development in this field, primarily the problem of selection of key performance indicators. It’s been founded that administrative measures stimulated the pursuit of a number of articles published in scientific journals hinders the development of science. Methodological errors - emphasis on citation indexes, impact factors, etc. - lead to wrong management decisions. As the experience of the UK, an expertise should be applied in the management of science. The article briefly discusses some of the drawbacks of the system of scientific specialties. It is proposed to expand research on the science of science and scientific activity controlling. We have also discussed the problems of controlling in applied research organizations

  10. Acute effects of three different circuit weight training protocols on blood lactate, heart rate, and rating of perceived exertion in recreationally active women.

    Science.gov (United States)

    Skidmore, Brook L; Jones, Margaret T; Blegen, Mark; Matthews, Tracey D

    2012-01-01

    Interval and circuit weight training are popular training methods for maximizing time-efficiency, and are purported to deliver greater physiological benefits faster than traditional training methods. Adding interval training into a circuit weight-training workout may further enhance the benefits of circuit weight training by placing increased demands upon the cardiovascular system. Our purpose was to compare acute effects of three circuit weight training protocols 1) traditional circuit weight training, 2) aerobic circuit weight training, and 3) combined circuit weight-interval training on blood lactate (BLA), heart rate (HR), and ratings of perceived exertion (RPE). Eleven recreationally active women completed 7 exercise sessions. Session 1 included measurements of height, weight, estimated VO2max, and 13 repetition maximum (RM) testing of the weight exercises. Sessions 2-4 were held on non-consecutive days for familiarization with traditional circuit weight training (TRAD), aerobic circuit weight training (ACWT), and combined circuit weight-interval training (CWIT) protocols. In sessions 5-7, TRAD, ACWT, and CWIT were performed in a randomized order ≥ 72 hr apart for measures of BLA, HR, and RPE at pre-exercise and following each of three mini-circuit weight training stations. Repeated-measures ANOVAs yielded significant interactions (p workouts into exercise programming may enhance fitness benefits and maximize time-efficiency more so than traditional circuit training methods. PMID:24150076

  11. Analysis of AC Switch Machine in Switch Control Circuit%交流转辙机道岔控制电路重点解析

    Institute of Scientific and Technical Information of China (English)

    王渝

    2012-01-01

    This paper systematically sorts out and summarizes the key circuits in the switch control circuits of AC switch machine,including the starting circuit,the cutting off circuit,and the failure button relay circuit.And the author analyzes the key points of related designs,which are instructive to the design of AC switch control circuit in the future.%对交流转辙机道岔控制电路中启动电路、切断电路及故障按钮继电器电路等重点电路进行系统梳理和总结,并对相关的设计要点进行分析,对今后交流转辙机道岔控制电路的设计具有一定的指导意义。

  12. All optical controlled photonic integrated circuits using azo dye functionized sol-gel material

    Science.gov (United States)

    Ke, Xianjun

    The main focus of this dissertation is development and characterization of all-optical controllable azo dye functionized sol gel material, demonstrating a PIC fabrication technique on glass substrate using such material, and exploration and feasibility demonstration of three PIC functional devices namely optical variable attenuator, optical switches, and optical tunable filters using the material. The realization of all the devices in this dissertation are based on one material: dye functionalized sol-gel material. A photochromic sol-gel material functionalized with azo dye was synthesized and characterized. It possesses a photochromic characteristic under the control of green laser beam illumination. The material characteristics suggest the possibility of a new promising material platform candidate for the fabrication of alloptical controlled photonic integrated circuits. As the first potential application of the dye functionalized sol-gel material, an alloptical variable attenuator was designed and demonstrated. The optical variable attenuation is achieved in Mach-Zehnder interferometric configuration through all-optical modulation of sol-gel waveguide phase shifters. A 2 x 2 optical switch based on multimode interference (MMI) waveguide structure is proposed in the dissertation. The schematic configuration of the optical switch consists of a cascade of two identical MMIs with two all-optical controlled phase shifters realized by using the photochromic sol-gel material. The cross or bar switch state of the optical switch is determined by the phase difference between the two sol-gel waveguide phase shifters. An all-optical tunable filter is designed and its feasibility demonstrated by using the sol-gel photochromic material. Except for the phase change demonstrated on sol-gel waveguide phase shifters, dynamic gratings were observed on sol-gel film when exposed to two interference beams. This reveals the possibility of realizing Bragg grating-based tunable filters

  13. Optimized circuit design for flexible 8-bit RFID transponders with active layer of ink-jet printed small molecule semiconductors

    NARCIS (Netherlands)

    Kjellander, B.K.C.; Smaal, W.T.T.; Myny, K.; Genoe, J.; Dehaene, W.; Heremans, P.; Gelinck, G.H.

    2013-01-01

    We ink-jet print a blend of 6,13-bis(triisopropyl-silylethynyl)pentacene and polystyrene as the active layer for flexible circuits. The discrete ink-jet printed transistors exhibit a saturation mobility of 0.5 cm2 V -1 s-1. The relative spread in transistor characteristics can be very large. This sp

  14. Active books: the design of an implantable stimulator that minimizes cable count using integrated circuits very close to electrodes.

    Science.gov (United States)

    Liu, Xiao; Demosthenous, Andreas; Vanhoestenberghe, Anne; Jiang, Dai; Donaldson, Nick

    2012-06-01

    This paper presents an integrated stimulator that can be embedded in implantable electrode books for interfacing with nerve roots at the cauda equina. The Active Book overcomes the limitation of conventional nerve root stimulators which can only support a small number of stimulating electrodes due to cable count restriction through the dura. Instead, a distributed stimulation system with many tripole electrodes can be configured using several Active Books which are addressed sequentially. The stimulator was fabricated in a 0.6-μm high-voltage CMOS process and occupies a silicon area of 4.2 × 6.5 mm(2). The circuit was designed to deliver up to 8 mA stimulus current to tripole electrodes from an 18 V power supply. Input pad count is limited to five (two power and three control lines) hence requiring a specific procedure for downloading stimulation commands to the chip and extracting information from it. Supported commands include adjusting the amplitude of stimulus current, varying the current ratio at the two anodes in each channel, and measuring relative humidity inside the chip package. In addition to stimulation mode, the chip supports quiescent mode, dissipating less than 100 nA current from the power supply. The performance of the stimulator chip was verified with bench tests including measurements using tripoles in saline. PMID:23853144

  15. A Component-Minimized Single-Phase Active Power Decoupling Circuit with Reduced Current Stress to Semiconductor Switches

    DEFF Research Database (Denmark)

    Tang, Yi; Blaabjerg, Frede

    2015-01-01

    This letter proposes a novel circuit topology which can realize the power decoupling function without adding additional active switches into the circuit. The dc-link capacitor of a full bridge rectifier is split into two identical parts and the midpoint is connected to one leg through a filter...... component, e.g. inductors or film capacitors for ripple energy storage because this task can be accomplished by the dc-link capacitors, and therefore its implementation cost can be minimized. Another unique feature of the proposed topology is that the current stress of power semiconductors can be reduced...

  16. Control of the boric acid concentration in the primary circuit by ion-exchanger Varion AT-660

    International Nuclear Information System (INIS)

    In order to control the output of VVER type nuclear power plants the variation of the boric acid concentration of the primary circuit can be used. The possibility of direct boric acid control in the primary circuit as well as the cleaning technology of boric acid solution by means of ion exchangers were studied. The equilibrium boric acid capacity of Varion AT-N (Varion AT-660) resin of nuclear grade purity was determined under dynamic conditions at various temperatures and concentrations. As a result, at a given concentration and amount of the resin, the desired change in the boric acid concentration of the heat transfer medium can be attained by the necessary adjustment of the temperature of the incoming solution to the ion exchanger. (Sz.J.)

  17. Dextromethorphan mediated bitter taste receptor activation in the pulmonary circuit causes vasoconstriction.

    Directory of Open Access Journals (Sweden)

    Jasbir D Upadhyaya

    Full Text Available Activation of bitter taste receptors (T2Rs in human airway smooth muscle cells leads to muscle relaxation and bronchodilation. This finding led to our hypothesis that T2Rs are expressed in human pulmonary artery smooth muscle cells and might be involved in regulating the vascular tone. RT-PCR was performed to reveal the expression of T2Rs in human pulmonary artery smooth muscle cells. Of the 25 T2Rs, 21 were expressed in these cells. Functional characterization was done by calcium imaging after stimulating the cells with different bitter agonists. Increased calcium responses were observed with most of the agonists, the largest increase seen for dextromethorphan. Previously in site-directed mutational studies, we have characterized the response of T2R1 to dextromethorphan, therefore, T2R1 was selected for further analysis in this study. Knockdown with T2R1 specific shRNA decreased mRNA levels, protein levels and dextromethorphan-induced calcium responses in pulmonary artery smooth muscle cells by up to 50%. To analyze if T2Rs are involved in regulating the pulmonary vascular tone, ex vivo studies using pulmonary arterial and airway rings were pursued. Myographic studies using porcine pulmonary arterial and airway rings showed that stimulation with dextromethorphan led to contraction of the pulmonary arterial and relaxation of the airway rings. This study shows that dextromethorphan, acting through T2R1, causes vasoconstrictor responses in the pulmonary circuit and relaxation in the airways.

  18. Self-control of chaos in neural circuits with plastic electrical synapses

    Science.gov (United States)

    Zhigulin, V. P.; Rabinovich, M. I.

    2004-10-01

    Two kinds of connections are known to exist in neural circuits: electrical (also called gap junctions) and chemical. Whereas chemical synapses are known to be plastic (i. e., modifiable), but slow, electrical transmission through gap junctions is not modifiable, but is very fast. We suggest the new artificial synapse that combines the best properties of both: the fast reaction of a gap junction and the plasticity of a chemical synapse. Such a plastic electrical synapse can be used in hybrid neural circuits and for the development of neural prosthetics, i.e., implanted devices that can interact with the real nervous system. Based on the computer modelling we show that such a plastic electrical synapse regularizes chaos in the minimal neural circuit consisting of two chaotic bursting neurons.

  19. Circuits and methods for determination and control of signal transition rates in electrochemical cells

    Energy Technology Data Exchange (ETDEWEB)

    Jamison, David Kay

    2016-04-12

    A charge/discharge input is for respectively supplying charge to, or drawing charge from, an electrochemical cell. A transition modifying circuit is coupled between the charge/discharge input and a terminal of the electrochemical cell and includes at least one of an inductive constituent, a capacitive constituent and a resistive constituent selected to generate an adjusted transition rate on the terminal sufficient to reduce degradation of a charge capacity characteristic of the electrochemical cell. A method determines characteristics of the transition modifying circuit. A degradation characteristic of the electrochemical cell is analyzed relative to a transition rate of the charge/discharge input applied to the electrochemical cell. An adjusted transition rate is determined for a signal to be applied to the electrochemical cell that will reduce the degradation characteristic. At least one of an inductance, a capacitance, and a resistance is selected for the transition modifying circuit to achieve the adjusted transition rate.

  20. Adaptive feedback active noise control

    Science.gov (United States)

    Kuo, Sen M.; Vijayan, Dipa

    Feedforward active noise control (ANC) systems use a reference sensor that senses a reference input to the controller. This signal is assumed to be unaffected by the secondary source and is a good measure of the undesired noise to be cancelled by the system. The reference sensor may be acoustic (e.g., microphone) or non-acoustic (e.g., tachometer, optical transducer). An obvious problem when using acoustic sensors is that the reference signal may be corrupted by the canceling signal generated by the secondary source. This problem is known as acoustic feedback. One way of avoiding this is by using a feedback active noise control (FANC) system which dispenses with the reference sensor. The FANC technique originally proposed by Olson and May employs a high gain negative feedback amplifier. This system suffered from the drawback that the error microphone had to be placed very close to the loudspeaker. The operation of the system was restricted to low frequency range and suffered from instability due to the possibility of positive feedback. Feedback systems employing adaptive filtering techniques for active noise control were developed. This paper presents the FANC system modeled as an adaptive prediction scheme.

  1. Linear integrated circuits

    Science.gov (United States)

    Young, T.

    This book is intended to be used as a textbook in a one-semester course at a variety of levels. Because of self-study features incorporated, it may also be used by practicing electronic engineers as a formal and thorough introduction to the subject. The distinction between linear and digital integrated circuits is discussed, taking into account digital and linear signal characteristics, linear and digital integrated circuit characteristics, the definitions for linear and digital circuits, applications of digital and linear integrated circuits, aspects of fabrication, packaging, and classification and numbering. Operational amplifiers are considered along with linear integrated circuit (LIC) power requirements and power supplies, voltage and current regulators, linear amplifiers, linear integrated circuit oscillators, wave-shaping circuits, active filters, DA and AD converters, demodulators, comparators, instrument amplifiers, current difference amplifiers, analog circuits and devices, and aspects of troubleshooting.

  2. Optical Sensing Circuit Using Low-Temperature Polycrystalline Silicon p-Type Thin-Film Transistors and p-Intrinsic-Metal Diode for Active Matrix Displays with Optical Input Functions

    Science.gov (United States)

    Lim, Han-Sin; Kwon, Oh-Kyong

    2009-03-01

    An optical sensing circuit composed of low-temperature polycrystalline silicon (LTPS) p-type thin-film transistors (TFTs) and a p-intrinsic-metal (p-i-m) diode is proposed for image scanning and touch sensing functions. Because it is a very difficult challenge to integrate both display pixels and optical sensing circuits into the restricted pixel area, the number of additional devices and control signal lines must be minimized. Therefore, two p-type TFTs, one p-i-m diode, one capacitor, and one signal line are added to display pixel for the proposed optical sensing circuit. Active matrix liquid crystal display (AMLCD) and active matrix organic light-emitting diode (AMOLED) pixels with the proposed optical sensing circuit have image scanning and touch sensing functions, respectively. Through the measurement of the proposed circuit under the condition of incident light varying from 0 to 10,000 lx, we verified that the dynamic and output ranges of the proposed circuit are 30 dB and 1.5 V, respectively.

  3. Novel Active Combustion Control Valve

    Science.gov (United States)

    Caspermeyer, Matt

    2014-01-01

    This project presents an innovative solution for active combustion control. Relative to the state of the art, this concept provides frequency modulation (greater than 1,000 Hz) in combination with high-amplitude modulation (in excess of 30 percent flow) and can be adapted to a large range of fuel injector sizes. Existing valves often have low flow modulation strength. To achieve higher flow modulation requires excessively large valves or too much electrical power to be practical. This active combustion control valve (ACCV) has high-frequency and -amplitude modulation, consumes low electrical power, is closely coupled with the fuel injector for modulation strength, and is practical in size and weight. By mitigating combustion instabilities at higher frequencies than have been previously achieved (approximately 1,000 Hz), this new technology enables gas turbines to run at operating points that produce lower emissions and higher performance.

  4. Monolithic microwave integrated circuit with integral array antenna

    International Nuclear Information System (INIS)

    A monolithic microwave integrated circuit including an integral array antenna. The system includes radiating elements, feed network, phasing network, active and/or passive semiconductor devices, digital logic interface circuits and a microcomputer controller simultaneously incorporated on a single substrate by means of a controlled fabrication process sequence

  5. Modeling and control of a LN2-GN2 operated closed circuit cryogenic wind tunnel

    Science.gov (United States)

    Balakrishna, S.; Thibodeaux, J. J.

    1979-01-01

    An explicit but simple lumped parameter nonlinear multivariable model of a LN2-GN2-operated closed circuit cryogenic wind tunnel has been developed and its basic features have been experimentally validated. The model describes the mass-energy interaction involved in the cryogenic tunnel process and includes the real gas properties of nitrogen gas.

  6. Neurobiological Circuits Regulating Attention, Cognitive Control, Motivation, and Emotion: Disruptions in Neurodevelopmental Psychiatric Disorders

    Science.gov (United States)

    Arnsten, Amy F. T.; Rubia, Katya

    2012-01-01

    Objective: This article aims to review basic and clinical studies outlining the roles of prefrontal cortical (PFC) networks in the behavior and cognitive functions that are compromised in childhood neurodevelopmental disorders and how these map into the neuroimaging evidence of circuit abnormalities in these disorders. Method: Studies of animals,…

  7. Modeling of active control of external magnetohydrodynamic instabilities

    International Nuclear Information System (INIS)

    A general circuit formulation of resistive wall mode (RWM) feedback stabilization developed by Boozer [Phys. Plasmas 5, 3350 (1998)] has been used as the basis for the VALEN computer code that calculates the performance of an active control system in arbitrary geometry. The code uses a finite element representation of a thin shell structure in an integral formulation to model arbitrary conducting walls. This is combined with a circuit representation of stable and unstable plasma modes. Benchmark comparisons of VALEN results with large aspect ratio analytic model of the current driven kink mode are in very good agreement. VALEN also models arbitrary sensors, control coils, and the feedback logic connecting these sensors and control coils to provide a complete simulation capability for feedback control of plasma instabilities. VALEN modeling is in good agreement with experimental results on DIII-D [Garofalo et al., Nucl. Fusion 40, 1491 (2000)] and HBT-EP [Cates et al., Phys. Plasmas 7, 3133 (2000)]. VALEN feedback simulations have also been used to evaluate and optimize the sensor/coil configurations for present and planned RWM experiments on DIII-D. These studies have shown a clear advantage for the use of local poloidal field sensors driving a 'mode control' feedback logic control loop and configurations which minimize the control coil coupling to the stabilizing resistive wall

  8. Measuring circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for measuring circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listings

  9. Circuit theory

    International Nuclear Information System (INIS)

    This book is divided into fourteen chapters, which deals with circuit theory of basis, sinusoidal alternating current on cycle and frequency, basics current circuit about R.L, C circuit and resonant circuit, current power, general linear circuit, inductive coupling circuit and vector locus on an alternating current bridge and mutual inductance and coupling coefficient, multiphase alternating current and method of symmetrical coordinates, non-sinusoidal alternating current, two terminal network, four terminal network, transient of circuits, distributed line circuit constant, frequency characteristic and a filter and Laplace transformation.

  10. Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control

    Energy Technology Data Exchange (ETDEWEB)

    S.K. Kawatra; T.C. Eisele; T. Weldum; D. Larsen; R. Mariani; J. Pletka

    2005-07-01

    The goal of this project was to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process were used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced could be minimized. The goal was to save energy by reducing the amount of material that was ground below the target size, while simultaneously reducing the quantity of materials wasted as ''slimes'' that were too fine to be useful. Extensive plant sampling and mathematical modeling of the grinding circuits was carried out to determine how to correct this problem. The approaches taken included (1) Modeling of the circuit to determine process bottlenecks that restrict flowrates in one area while forcing other parts of the circuit to overgrind the material; (2) Modeling of hydrocyclones to determine the mechanisms responsible for retaining fine, high-density particles in the circuit until they are overground, and improving existing models to accurately account for this behavior; and (3) Evaluation of the potential of advanced technologies to improve comminution efficiency and produce sharper product size distributions with less overgrinding. The mathematical models were used to simulate novel circuits for minimizing overgrinding and increasing throughput, and it is estimated that a single plant grinding 15 million tons of ore per year saves up to 82.5 million kWhr/year, or 8.6 x 10{sup 11} BTU/year. Implementation of this technology in the midwestern iron ore industry, which grinds an estimated 150 million tons of ore annually to produce over 50 million tons of iron ore concentrate, would save an estimated 1 x 10{sup 13} BTU/year.

  11. Active control of the noise

    International Nuclear Information System (INIS)

    The problems of acoustic noise are more and more preponderant in the measure in that the amount of equipment and industrial machinery is increased such as fans, transformers, compressors etc. the use of devices passive mechanics for the reduction of the noise is effective and very appreciated because its effects embrace a wide range of acoustic frequency. However, to low frequencies, such devices become too big and expensive besides that present a tendency to do not effective. The control of active noise, CAN, using the electronic generation anti-noise, constitutes an interesting solution to the problem because their operation principle allows achieving an appreciable reduction of the noise by means of the use of compact devices. The traditional techniques for the control of acoustic noise like barriers and silenced to attenuate it, are classified as passive and their works has been accepted as norm as for the treatment of problems of noise it refers. Such techniques are considered in general very effective in the attenuation of noise of wide band. However, for low frequency, the required passive structures are too big and expensive; also, their effectiveness diminishes flagrantly, that which makes them impractical in many applications. The active suppression is profiled like a practical alternative for the reduction of acoustic noise. The idea in the active treatment of the noise it contemplates the use of a device electro-acoustic, like a speaker for example that it cancels to the noise by the generation of sounds of Same width and of contrary phase (anti-noise). The cancellation phenomenon is carried out when the ant-noise combines acoustically with the noise, what is in the cancellation of both sounds. The effectiveness of the cancellation of the primary source of noise depends on the precision with which the width and the phase of the generated ant-noise are controlled. The active control of noise, ANC (activates noise control), it is being investigated for

  12. Experimental Comparison of two Active Vibration Control Approaches: Velocity Feedback and Negative Capacitance Shunt Damping

    Science.gov (United States)

    Beck, Benjamin; Schiller, Noah

    2013-01-01

    This paper outlines a direct, experimental comparison between two established active vibration control techniques. Active vibration control methods, many of which rely upon piezoelectric patches as actuators and/or sensors, have been widely studied, showing many advantages over passive techniques. However, few direct comparisons between different active vibration control methods have been made to determine the performance benefit of one method over another. For the comparison here, the first control method, velocity feedback, is implemented using four accelerometers that act as sensors along with an analog control circuit which drives a piezoelectric actuator. The second method, negative capacitance shunt damping, consists of a basic analog circuit which utilizes a single piezoelectric patch as both a sensor and actuator. Both of these control methods are implemented individually using the same piezoelectric actuator attached to a clamped Plexiglas window. To assess the performance of each control method, the spatially averaged velocity of the window is compared to an uncontrolled response.

  13. Control of internal and external short circuits in lithium batteries using a composite thermal switch

    Science.gov (United States)

    Mcdonald, Robert C.; Pickett, Jerome; Goebel, Franz

    1991-01-01

    A composite material has been developed, consisting of a blend of metal and fluorocarbon particles, which behaves as an electronic conductor at room temperature and which abruptly becomes an insulator at a predetermined temperature. This switching behavior results from the difference in thermal expansion coefficients between the conductive and non-conductive portions of the composite. This material was applied as a thin film between the carbon cathode in Li/SOCl2 cells, and the metallic cathode current collector. Using test articles incorporating this feature it was shown that lithium cells externally heated or internally heated during a short circuit lost rate capability and the ability to overheat well below the melting point of lithium (180 C). Thus, during an internal or external cell short circuit, the potential for thermal runaway involving reactions of molten lithium is avoided.

  14. A Digital Controller for Active Aeroelastic Controls

    OpenAIRE

    Ueda, Tetsuhiko; MUROTA, Katsuichi; 上田, 哲彦; 室田, 勝一

    1989-01-01

    A high-speed digital controller for aeroelastic controls was designed and made. The purpose was to minimize adverse phase lag which is inevitably produced by the CPU time of digital processing. The delay deteriorates control performances on rather rapid phenomena like aircraft flutter. With fix-point operation the controller realized 417 microseconds of throughput time including the A/D and D/A conversion. This corresponds to a high sampling rate of 2.4kHz. The controller furnishes two channe...

  15. Spine Pruning Drives Antipsychotic-sensitive Locomotion via Circuit Control of Striatal Dopamine

    OpenAIRE

    Kim, Il Hwan; Rossi, Mark A.; Aryal, Dipendra K.; Racz, Bence; Kim, Namsoo; Uezu, Akiyoshi; Wang, Fan; Wetsel, William C.; Weinberg, Richard J.; Yin, Henry; Soderling, Scott H.

    2015-01-01

    Psychiatric and neurodevelopmental disorders may arise from anomalies in long-range neuronal connectivity downstream of pathologies in dendritic spines. However, the mechanisms that may link spine pathology to circuit abnormalities relevant to atypical behavior remain unknown. Using a mouse model to conditionally disrupt a critical regulator of the dendritic spine cytoskeleton, Arp2/3, we report here a molecular mechanism that unexpectedly reveals the interrelationship of progressive spine pr...

  16. Remote Query Resonant-Circuit Sensors for Monitoring of Bacteria Growth: Application to Food Quality Control

    OpenAIRE

    Bachas, Leonidas G.; Libby G. Puckett; Craig A. Grimes; J. Samuel Bitler; Keat Ghee Ong

    2002-01-01

    This paper presents a technique for in-situ remote query monitoring of bacteria growth utilizing a printed thin or thick-film sensor comprised of an inductor-capacitor (LC) resonant circuit. The sensor, which is placed within the biological medium of interest and remotely detected using a loop antenna, measures the complex permittivity of the medium. Since bacteria growth increases the complex permittivity of a biological medium the LC sensor can be used to determine bacteria concentration. T...

  17. From blockade to transparency: controllable photon transmission through a circuit QED system

    OpenAIRE

    Liu, Yu-xi; Xu, Xun-Wei; Miranowicz, Adam; Nori, Franco

    2012-01-01

    A strong photon-photon nonlinear interaction is a necessary condition for photon blockade. Moreover, this nonlinearity can also result a bistable behavior in the cavity field. We analyze the relation between detecting field and photon blockade in a superconducting circuit QED system, and show that photon blockade cannot occur when the detecting field is in the bistable regime. This photon blockade is the microwave-photonics analog of the Coulomb blockade. We further demonstrate that the photo...

  18. A low-power circuit for piezoelectric vibration control by synchronized switching on voltage sources

    OpenAIRE

    Shen, Hui; Qiu, Jinhao; Ji, Hongli; Zhu, Kongjun; Balsi, Marco; Giorgio, Ivan; Dell'Isola, Francesco

    2010-01-01

    In the paper, a vibration damping system powered by harvested energy with implementation of the so-called SSDV (synchronized switch damping on voltage source) technique is designed and investigated. In the semi-passive approach, the piezoelectric element is intermittently switched from open-circuit to specific impedance synchronously with the structural vibration. Due to this switching procedure, a phase difference appears between the strain induced by vibration and the resulting voltage, thu...

  19. Development of quench detection/protection system based on active power method for superconducting magnet by using capacitor circuit

    International Nuclear Information System (INIS)

    Highlights: ► The authors have presented an active power method for quench detection. ► A method for improving its characteristics using a capacitor circuit was proposed. ► Quench detection/protection test for a Bi2223 superconducting coil was carried out. ► The proposed method was more useful than the conventional one. -- Abstract: When a quench occurs in a superconducting magnet, excessive joule heating in normal region may damage the magnet. It is necessary to detect the quench as soon as possible and discharge magnetic energy stored in the magnet. The authors have presented a quench detection/protection system based on an active power method which detects the quench regardless of a self-inductive and mutual-inductive voltages and electromagnetic noise. In the conventional active power method, the inductive voltages are removed by cancel coils. In this paper, the authors propose a method to cancel an inductive voltage using a capacitor circuit. The quench detection/protection system becomes more precise and smaller than the conventional system through the capacitor circuit

  20. A Bmp/Admp regulatory circuit controls maintenance and regeneration of dorsal-ventral polarity in planarians.

    Science.gov (United States)

    Gaviño, Michael A; Reddien, Peter W

    2011-02-22

    Animal embryos have diverse anatomy and vary greatly in size. It is therefore remarkable that a common signaling pathway, BMP signaling, controls development of the dorsoventral (DV) axis throughout the Bilateria. In vertebrates, spatially opposed expression of the BMP family proteins Bmp4 and Admp (antidorsalizing morphogenetic protein) can promote restoration of DV pattern following tissue removal. bmp4 orthologs have been identified in all three groups of the Bilateria (deuterostomes, ecdysozoans, and lophotrochozoans). By contrast, the absence of admp orthologs in ecdysozoans such as Drosophila and C. elegans has suggested that a regulatory circuit of oppositely expressed bmp4 and admp genes represents a deuterostome-specific innovation. Here we describe the existence of spatially opposed bmp and admp expression in a protostome. An admp ortholog (Smed-admp) is expressed ventrally and laterally in adult Schmidtea mediterranea planarians, opposing the dorsal-pole expression of Smed-bmp4. Smed-admp is required for regeneration following parasagittal amputation. Furthermore, Smed-admp promotes Smed-bmp4 expression and Smed-bmp4 inhibits Smed-admp expression, generating a regulatory circuit that buffers against perturbations of Bmp signaling. These results suggest that a Bmp/Admp regulatory circuit is a central feature of the Bilateria, used broadly for the establishment, maintenance, and regeneration of the DV axis. PMID:21295483

  1. Field Experiments on 10 kV Switching Shunt Capacitor Banks Using Ordinary and Phase-Controlled Vacuum Circuit Breakers

    Directory of Open Access Journals (Sweden)

    Wenxia Sima

    2016-01-01

    Full Text Available During the switching on/off of shunt capacitor banks in substations, vacuum circuit breakers (VCBs are required to switch off or to switch on the capacitive current. Therefore, the VCBs have to be operated under a harsh condition to ensure the reliability of the equipment. This study presents a complete comparison study of ordinary and phase-controlled VCBs on switching 10 kV shunt capacitor banks. An analytical analysis for switching 10 kV shunt capacitor banks is presented on the basis of a reduced circuit with an ungrounded neutral. A phase selection strategy for VCBs to switch 10 kV shunt capacitor banks is proposed. Switching on current waveforms and switching off overvoltage waveforms with, and without, phase selection were measured and discussed by field experiments in a 110 kV substation in Chongqing, China. Results show that the operation of phase-controlled VCBs for 10 kV switching shunt capacitor banks is stable, and phase-controlled VCBs can be used to implement the 10 kV switching on/off shunt capacitor banks to limit the transient overvoltage and overcurrent. The values of overvoltage and inrush current using phase-controlled VCBs are all below those with ordinary VCBs.

  2. LOGIC CIRCUIT

    Science.gov (United States)

    Strong, G.H.; Faught, M.L.

    1963-12-24

    A device for safety rod counting in a nuclear reactor is described. A Wheatstone bridge circuit is adapted to prevent de-energizing the hopper coils of a ball backup system if safety rods, sufficient in total control effect, properly enter the reactor core to effect shut down. A plurality of resistances form one arm of the bridge, each resistance being associated with a particular safety rod and weighted in value according to the control effect of the particular safety rod. Switching means are used to switch each of the resistances in and out of the bridge circuit responsive to the presence of a particular safety rod in its effective position in the reactor core and responsive to the attainment of a predetermined velocity by a particular safety rod enroute to its effective position. The bridge is unbalanced in one direction during normal reactor operation prior to the generation of a scram signal and the switching means and resistances are adapted to unbalance the bridge in the opposite direction if the safety rods produce a predetermined amount of control effect in response to the scram signal. The bridge unbalance reversal is then utilized to prevent the actuation of the ball backup system, or, conversely, a failure of the safety rods to produce the predetermined effect produces no unbalance reversal and the ball backup system is actuated. (AEC)

  3. A microcontroller-based interface circuit for data acquisition and control of a micromechanical thermal flow sensor

    International Nuclear Information System (INIS)

    In the present work, a special microcontroller-based data acquisition and control system was designed and fabricated, for fast and accurate flow measurements with programmable modes of operation. The system can apply predetermined power to the heater and simultaneously is able of monitoring both the thermopile signal and the heater current. An RS232 connection was also implemented for the communication with the outside world. The interface circuit was adapted to the micromechanical flow sensor for evaluation. Various sensor parameters were extracted in both laminar and turbulent flow conditions. The sensor responses with three operation modes (constant voltage, power and temperature) were also obtained

  4. A Ka-band high power monolithic HEMT VCO using a sub-resonator circuit with phase control architecture

    OpenAIRE

    Kashiwa, Takuo; Katoh, Takayuki; Ishida, Takao; Kurusu, Hitoshi; Mitsui, Yasuo

    1998-01-01

    This paper reports on a high output performance of a Ka-band monolithic HEMT Voltage Controlled Oscillator(VCO). This VCO has a sub-resonator in order to avoid reduction in Q-factor of a resonator. Circuit elements of the sub-resonator are optimized to achieve a wide tuning range as well as high output power and low phase noise performances. In addition, an AlGaAs/InGaAs double-hetero struc­ture High Electron Mobility Transistor(HEMT) is employed in the VCO to obtain a high output per­formanc...

  5. Field Experiments on 10 kV Switching Shunt Capacitor Banks Using Ordinary and Phase-Controlled Vacuum Circuit Breakers

    OpenAIRE

    Wenxia Sima; Mi Zou; Qing Yang; Ming Yang; Licheng Li

    2016-01-01

    During the switching on/off of shunt capacitor banks in substations, vacuum circuit breakers (VCBs) are required to switch off or to switch on the capacitive current. Therefore, the VCBs have to be operated under a harsh condition to ensure the reliability of the equipment. This study presents a complete comparison study of ordinary and phase-controlled VCBs on switching 10 kV shunt capacitor banks. An analytical analysis for switching 10 kV shunt capacitor banks is presented on the basis of ...

  6. Optically controlled phased array antenna concepts using GaAs monolithic microwave integrated circuits

    Science.gov (United States)

    Kunath, R. R.; Bhasin, K. B.

    1986-01-01

    The desire for rapid beam reconfigurability and steering has led to the exploration of new techniques. Optical techniques have been suggested as potential candidates for implementing these needs. Candidates generally fall into one of two areas: those using fiber optic Beam Forming Networks (BFNs) and those using optically processed BFNs. Both techniques utilize GaAs Monolithic Microwave Integrated Circuits (MMICs) in the BFN, but the role of the MMIC for providing phase and amplitude variations is largely eliminated by some new optical processing techniques. This paper discusses these two types of optical BFN designs and provides conceptual designs of both systems.

  7. EFFECT OF NEBULIZED COLISTIN ON THE VENTILATOR CIRCUIT: A PROSPECTIVE PILOT CASE-CONTROL STUDY FROM A SINGLE CANCER CENTER

    Directory of Open Access Journals (Sweden)

    Iyad M Ghonimat

    2015-04-01

    Full Text Available Nebulized colistin (NC is used for the treatment of pneumonia due to multidrug-resistant Gram-negative bacteria. In this one-year case-control study, our objective was to evaluate the effect of NC on the ventilator circuit (VC components. The case group consisted of 25 mechanically-ventilated patients who received NC, while the control group was 25 mechanically-ventilated patients who did not receive NC. Respiratory therapists inspected the VC every 4 hrs and whenever a ventilator alarm was reported. The VC component was changed if the alarm did not subside after necessary measures were performed. Patients from both groups were treated at the adult ICU in King Hussein Cancer Center (KHCC. In the case group, 22(88% patients required changing at least one of the circuit components (flow sensor, exhalation membrane, or nebulizer kit. The median number of changes (range per patient of the flow sensor, exhalation membrane, and nebulizer kit were: 2(1-3, 2(1-6, and 1(1-2, respectively. Large amounts of white crystals, which resembled the colistin powder, were reported on the replaced VC components. The flow sensor was changed in 2 control patients, but white crystals were absent. Crystals obtained from one case subject were confirmed to be colistin by chromatographic mass spectroscopy. Further studies are needed to evaluate the effect of crystal formation on the efficacy of NC and clinical outcomes.

  8. Striatal plasticity and basal ganglia circuit function

    OpenAIRE

    Kreitzer, Anatol C.; Malenka, Robert C.

    2008-01-01

    The dorsal striatum, which consists of the caudate and putamen, is the gateway to the basal ganglia. It receives convergent excitatory afferents from cortex and thalamus and forms the origin of the direct and indirect pathways—distinct basal ganglia circuits involved in motor control. It is also a major site of activity-dependent synaptic plasticity. Striatal plasticity alters the transfer of information throughout basal ganglia circuits and may represent a key neural substrate for adaptive m...

  9. Observation of chaotic beats in a driven memristive Chua's circuit

    OpenAIRE

    Ahamed, A. Ishaq; Srinivasan, K.; Murali, K.; Lakshmanan, M.

    2010-01-01

    In this paper, a time varying resistive circuit realising the action of an active three segment piecewise linear flux controlled memristor is proposed. Using this as the nonlinearity, a driven Chua's circuit is implemented. The phenomenon of chaotic beats in this circuit is observed for a suitable choice of parameters. The memristor acts as a chaotically time varying resistor (CTVR), switching between a less conductive OFF state and a more conductive ON state. This chaotic switching is govern...

  10. Improving the performance of hysteresis direct torque control of IPMSM using active filter topology

    Indian Academy of Sciences (India)

    Kayhan Gulez; Ali Ahmed Adam; Halit Pastaci

    2006-06-01

    This paper describes an active filter topology to improve the performance of hysteresis direct torque control (HDTC) of interior permanent magnet synchronous motor (IPMSM). The filter topology consists of an active filter and two RLC filters, and is connected to the main power circuit through a 1:1 transformer. The active filter is characterized by detecting the harmonics in the motor phase voltages and injecting equivalent harmonic voltages to produce almost sinusoidal voltage waveform to the motor terminals. The active filter uses hysteresis voltage controller while the motor main circuit uses hysteresis direct torque control. The simulation results of this combined control structure show considerable torque ripple reduction in the steady state range and adequate dynamic torque performance as well as considerable harmonic voltage and EMI noise reduction.

  11. Control of a Two-Stage Direct Power Converter with a Single Voltage Sensor Mounted in the Intermediary Circuit

    DEFF Research Database (Denmark)

    Klumpner, Christian; Wheeler, P.; Blaabjerg, Frede

    2004-01-01

    Controlling a converter requires not only a powerful processors but also accurate voltage and current sensors and fast and precise analogue-digital converters, which increase the cost per kW of the assembly, especially in the low power range. A matrix converter requires less transducers than a back......-to-back Voltage Source Converter because of the inherent direct power transfer which doesn?t require a control loop of the dc-link voltage to balance the power of the rectifier and the inverter. On the other hand, two-stage Direct Power Converters (DPC) also perform direct power conversion as the matrix...... converters but in two stages (AC/DC/AC) without using energy storage in the intermediary circuit. They also offer the possibility to reduce the number of switches compared to the standard single-stage matrix converter. This paper presents a new method to control a two-stage DPC providing sine-wave in sine...

  12. Hypoxia activates a latent circuit for processing gustatory information in C. elegans

    OpenAIRE

    Pocock, Roger; Hobert, Oliver

    2010-01-01

    Dedicated neuronal circuits enable animals to engage in specific behavioral responses to environmental stimuli. We demonstrate here that hypoxic stress enhances gustatory sensory perception via novel circuitry in the nematode Caenorhabditis elegans. The hypoxia-inducible transcription factor HIF-1 upregulates serotonin (5-HT) expression in specific sensory neurons not normally required for chemosensation. 5-HT subsequently signals to promote hypoxia-enhanced sensory perception using a metabot...

  13. Active Spacecraft Potential Control Investigation

    Science.gov (United States)

    Torkar, K.; Nakamura, R.; Tajmar, M.; Scharlemann, C.; Jeszenszky, H.; Laky, G.; Fremuth, G.; Escoubet, C. P.; Svenes, K.

    2016-03-01

    In tenuous plasma the floating potential of sunlit spacecraft reaches tens of volts, positive. The corresponding field disturbs measurements of the ambient plasma by electron and ion sensors and can reduce micro-channel plate lifetime in electron detectors owing to large fluxes of attracted photoelectrons. Also the accuracy of electric field measurements may suffer from a high spacecraft potential. The Active Spacecraft Potential Control (ASPOC) neutralizes the spacecraft potential by releasing positive charge produced by indium ion emitters. The method has been successfully applied on other spacecraft such as Cluster and Double Star. Two ASPOC units are present on each spacecraft. Each unit contains four ion emitters, whereby one emitter per instrument is operated at a time. ASPOC for the Magnetospheric Multiscale (MMS) mission includes new developments in the design of the emitters and the electronics. New features include the use of capillaries instead of needles, new materials for the emitters and their internal thermal insulators, an extended voltage and current range of the electronics, both for ion emission and heating purposes, and a more capable control software. This enables lower spacecraft potentials, higher reliability, and a more uniform potential structure in the spacecraft's sheath compared to previous missions. Results from on-ground testing demonstrate compliance with requirements. Model calculations confirm the findings from previous applications that the plasma measurements will not be affected by the beam's space charge. Finally, the various operating modes to adapt to changing boundary conditions are described along with the main data products.

  14. Model of Reentrant Ventricular Tachycardia based upon Infarct Border Zone Geometry Predicts Reentrant Circuit Features as Determined by Activation Mapping

    Science.gov (United States)

    Ciaccio, Edward J; Ashikaga, Hiroshi; Kaba, Riyaz A; Cervantes, Daniel; Hopenfeld, Bruce; Wit, Andrew L; Peters, Nicholas S; McVeigh, Elliot R; Garan, Hasan; Coromilas, James

    2008-01-01

    Background Infarct border zone (IBZ) geometry likely affects inducibility and characteristics of postinfarction reentrant ventricular tachycardia, but the connection has not been established. Objective To determine characteristics of post infarction ventricular tachycardia in the IBZ. Methods A geometric model describing the relationship between IBZ geometry and wavefront propagation in reentrant circuits was developed. Based on the formulation, slow conduction and block was expected to coincide with areas where IBZ thickness (T) is minimal and the local spatial gradient in thickness (ΔT) is maximal, so that the degree of wavefront curvature ρ ∝ ΔT/T is maximal. Regions of fastest conduction velocity were predicted to coincide with areas of minimum ΔT. In seven arrhythmogenic postinfarction canine heart experiments, tachycardia was induced by programmed stimulation, and activation maps were constructed from multichannel recordings. IBZ thickness was measured in excised hearts from histologic analysis or magnetic resonance imaging. Reentrant circuit properties were predicted from IBZ geometry and compared with ventricular activation maps following tachycardia induction. Results Mean IBZ thickness was 231±140µm at the reentry isthmus and 1440±770µm in the outer pathway (p<0.001). Mean curvature ρ was 1.63±0.45mm−1 at functional block line locations, 0.71±0.18mm−1 at isthmus entrance-exit points, and 0.33±0.13mm−1 in the outer reentrant circuit pathway. The mean conduction velocity about the circuit during reentrant tachycardia was 0.32±0.04mm/ms at entrance-exit points, 0.42±0.13mm/ms for the entire outer pathway, and 0.64±0.16mm/ms at outer pathway regions with minimum ΔT. Model sensitivity and specificity to detect isthmus location was 75.0±5.7% and 97.2±0.7%. Conclusions Reentrant circuit features as determined by activation mapping can be predicted on the basis of IBZ geometrical relationships. PMID:17675078

  15. ACUTE EFFECTS OF THREE DIFFERENT CIRCUIT WEIGHT TRAINING PROTOCOLS ON BLOOD LACTATE, HEART RATE, AND RATING OF PERCEIVED EXERTION IN RECREATIONALLY ACTIVE WOMEN

    Directory of Open Access Journals (Sweden)

    Brook L. Skidmore

    2012-12-01

    Full Text Available Interval and circuit weight training are popular training methods for maximizing time-efficiency, and are purported to deliver greater physiological benefits faster than traditional training methods. Adding interval training into a circuit weight-training workout may further enhance the benefits of circuit weight training by placing increased demands upon the cardiovascular system. Our purpose was to compare acute effects of three circuit weight training protocols 1 traditional circuit weight training, 2 aerobic circuit weight training, and 3 combined circuit weight-interval training on blood lactate (BLA, heart rate (HR, and ratings of perceived exertion (RPE. Eleven recreationally active women completed 7 exercise sessions. Session 1 included measurements of height, weight, estimated VO2max, and 13 repetition maximum (RM testing of the weight exercises. Sessions 2-4 were held on non-consecutive days for familiarization with traditional circuit weight training (TRAD, aerobic circuit weight training (ACWT, and combined circuit weight-interval training (CWIT protocols. In sessions 5-7, TRAD, ACWT, and CWIT were performed in a randomized order > 72 hr apart for measures of BLA, HR, and RPE at pre-exercise and following each of three mini-circuit weight training stations. Repeated-measures ANOVAs yielded significant interactions (p < 0.05 in BLA, HR, and RPE. Combined circuit weight- interval training (CWIT produced higher BLA (7.31 ± 0.37 vs. TRAD: 3.99 ± 0.26, ACWT: 4.54 ± 0.31 mmol.L-1, HR (83.51 ± 1.18 vs. TRAD: 70.42 ± 1.67, ACWT: 74.13 ± 1.43 beats.min-1 and RPE (8.14 ± 0.41 vs. TRAD: 5.06 ± 0.43, ACWT: 6.15 ± 0.42 at all measures. Aerobic circuit weight training (ACWT elicited greater RPE than traditional circuit weight training (TRAD at all measures. Including combined circuit weight-interval training (CWIT workouts into exercise programming may enhance fitness benefits and maximize time-efficiency more so than traditional circuit

  16. Active coupling control in densely packed subwavelength waveguides via dark mode

    CERN Document Server

    Suchowski, Haim; Hatakeyama, Taiki; Wu, Chihhui; Feng, Liang; OBrien, Kevin; Wang, Yuan; Zhang, Xiang

    2015-01-01

    The ever growing need for energy-efficient and fast communications is driving the development of highly integrated photonic circuits where controlling light at the nanoscale becomes the most critical aspect of information transfer . Directional couplers, two interacting optical waveguides placed in close proximity, are important building blocks in these integrated photonics circuits and have been employed as optical modulators and switches for high speed communication, data processing and integrated quantum operations. However, active control over the coupling between closely packed waveguides is highly desirable and yet remains a critical barrier towards ultra small footprint devices. A general approach to achieve active control in waveguide systems is to exploit optical nonlinearities enabled by a strong control pulse. However these devices suffer from the nonlinear absorption induced by the intense control pulse as the signal and its control propagate in the same waveguide. Here we experimentally demonstra...

  17. Dynamic signal processing by ribozyme-mediated RNA circuits to control gene expression

    Science.gov (United States)

    Shen, Shensi; Rodrigo, Guillermo; Prakash, Satya; Majer, Eszter; Landrain, Thomas E.; Kirov, Boris; Daròs, José-Antonio; Jaramillo, Alfonso

    2015-01-01

    Organisms have different circuitries that allow converting signal molecule levels to changes in gene expression. An important challenge in synthetic biology involves the de novo design of RNA modules enabling dynamic signal processing in live cells. This requires a scalable methodology for sensing, transmission, and actuation, which could be assembled into larger signaling networks. Here, we present a biochemical strategy to design RNA-mediated signal transduction cascades able to sense small molecules and small RNAs. We design switchable functional RNA domains by using strand-displacement techniques. We experimentally characterize the molecular mechanism underlying our synthetic RNA signaling cascades, show the ability to regulate gene expression with transduced RNA signals, and describe the signal processing response of our systems to periodic forcing in single live cells. The engineered systems integrate RNA–RNA interaction with available ribozyme and aptamer elements, providing new ways to engineer arbitrary complex gene circuits. PMID:25916845

  18. Remote Query Resonant-Circuit Sensors for Monitoring of Bacteria Growth: Application to Food Quality Control

    Directory of Open Access Journals (Sweden)

    Leonidas G. Bachas

    2002-06-01

    Full Text Available This paper presents a technique for in-situ remote query monitoring of bacteria growth utilizing a printed thin or thick-film sensor comprised of an inductor-capacitor (LC resonant circuit. The sensor, which is placed within the biological medium of interest and remotely detected using a loop antenna, measures the complex permittivity of the medium. Since bacteria growth increases the complex permittivity of a biological medium the LC sensor can be used to determine bacteria concentration. This paper presents results on monitoring of three different bacteria strains, Bacillus subtilis, Escherichia coli JM109, and Pseudomonas putida, demonstrating application of the sensor for monitoring bacteria growth in milk, meat, and beer. Due to its low unit cost and remote query detection, the sensor is potentially useful for commercial scale monitoring of food quality.

  19. Brain's reward circuits mediate itch relief. a functional MRI study of active scratching.

    Directory of Open Access Journals (Sweden)

    Alexandru D P Papoiu

    Full Text Available Previous brain imaging studies investigating the brain processing of scratching used an exogenous intervention mimicking scratching, performed not by the subjects themselves, but delivered by an investigator. In real life, scratching is a conscious, voluntary, controlled motor response to itching, which is directed to the perceived site of distress. In this study we aimed to visualize in real-time by brain imaging the core mechanisms of the itch-scratch cycle when scratching was performed by subjects themselves. Secondly, we aimed to assess the correlations between brain patterns of activation and psychophysical ratings of itch relief or pleasurability of scratching. We also compared the patterns of brain activity evoked by self-scratching vs. passive scratching. We used a robust tridimensional Arterial Spin Labeling fMRI technique that is less sensitive to motion artifacts: 3D gradient echo and spin echo (GRASE--Propeller. Active scratching was accompanied by a higher pleasurability and induced a more pronounced deactivation of the anterior cingulate cortex and insula, in comparison with passive scratching. A significant involvement of the reward system including the ventral tegmentum of the midbrain, coupled with a mechanism deactivating the periaqueductal gray matter (PAG, suggests that itch modulation operates in reverse to the mechanism known to suppress pain. Our findings not only confirm a role for the central networks processing reward in the pleasurable aspects of scratching, but also suggest they play a role in mediating itch relief.

  20. Circuits and filters handbook

    CERN Document Server

    Chen, Wai-Kai

    2003-01-01

    A bestseller in its first edition, The Circuits and Filters Handbook has been thoroughly updated to provide the most current, most comprehensive information available in both the classical and emerging fields of circuits and filters, both analog and digital. This edition contains 29 new chapters, with significant additions in the areas of computer-aided design, circuit simulation, VLSI circuits, design automation, and active and digital filters. It will undoubtedly take its place as the engineer's first choice in looking for solutions to problems encountered in the design, analysis, and behavi

  1. A Positive Buck Boost Converter with Mode Select Circuit and Feed Forward Techniques Using Fuzzy Logic Controller

    Directory of Open Access Journals (Sweden)

    Latha. S. C

    2014-11-01

    Full Text Available The portable devices development of semiconductor manufacturing technology, conversion efficiency, power consumption, and the size of devices have become the most important design criteria of switching power converters. For portable applications better conveniences extension of battery life and improves the conversion efficiency of power converters .It is essential to develop accurate switching power converters, which can reduce more wasted power energy. The proposed topology can achieve faster transient responses when the supply voltages are changed for the converter by making use of the feed forward network .With mode select circuit the conduction & switching losses are reduced the positive buck–boost converter operate in buck, buck–boost, or boost converter. By adding feed-forward techniques, the proposed converter can improve transient response when the supply voltages are changed. The designing, modeling & experimental results were verified in MATLAB/ Simulink. The fuzzy logic controller is used as controller.

  2. Circadian Control of the Estrogenic Circuits Regulating GnRH Secretion and the Preovulatory Luteinizing Hormone Surge

    Directory of Open Access Journals (Sweden)

    Lance J Kriegsfeld

    2012-05-01

    Full Text Available Female reproduction requires the precise temporal organization of interacting, estradiol-sensitive neural circuits that converge to optimally drive hypothalamo-pituitary-gonadal (HPG axis functioning. In mammals, the master circadian pacemaker in the suprachaismatic nucleus (SCN of the anterior hypothalamus coordinates reproductively-relevant neuroendocrine events necessary to maximize reproductive success. Likewise, in species where periods of fertility are brief, circadian oversight of reproductive function ensures that estradiol-dependent increases in sexual motivation coincide with ovulation. Across species, including humans, disruptions to circadian timing (e.g., through rotating shift work, night shift work, poor sleep hygiene lead to pronounced deficits in ovulation and fecundity. Despite the well-established roles for the circadian system in female reproductive functioning, the specific neural circuits and neurochemical mediators underlying these interactions are not fully understood. Most work to date has focused on the direct and indirect communication from the SCN to the GnRH system in control of the preovulatory LH surge. However, the same clock genes underlying circadian rhythms at the cellular level in SCN cells are also common to target cell populations of the SCN, including the GnRH neuronal network. Exploring the means by which the master clock synergizes with subordinate clocks in GnRH cells and its upstream modulatory systems represents an exciting opportunity to further understand the role of endogenous timing systems in female reproduction. Herein we provide an overview of the state of knowledge regarding interactions between the circadian timing system and estradiol-sensitive neural circuits driving GnRH secretion and the preovulatory LH surge.

  3. Fiber-Coupled Planar Light-Wave Circuit for Seed Laser Control in High Spectral Resolution Lidar Systems

    Science.gov (United States)

    Cook, Anthony; McNeil, Shirley; Switzer, Gregg; Battle, Philip

    2010-01-01

    Precise laser remote sensing of aerosol extinction and backscatter in the atmosphere requires a high-power, pulsed, frequency doubled Nd:YAG laser that is wavelength- stabilized to a narrow absorption line such as found in iodine vapor. One method for precise wavelength control is to injection seed the Nd:YAG laser with a low-power CW laser that is stabilized by frequency converting a fraction of the beam to 532 nm, and to actively frequency-lock it to an iodine vapor absorption line. While the feasibility of this approach has been demonstrated using bulk optics in NASA Langley s Airborne High Spectral Resolution Lidar (HSRL) program, an ideal, lower cost solution is to develop an all-waveguide, frequency-locked seed laser in a compact, robust package that will withstand the temperature, shock, and vibration levels associated with airborne and space-based remote sensing platforms. A key technology leading to this miniaturization is the integration of an efficient waveguide frequency doubling element, and a low-voltage phase modulation element into a single, monolithic, planar light-wave circuit (PLC). The PLC concept advances NASA's future lidar systems due to its compact, efficient and reliable design, thus enabling use on small aircraft and satellites. The immediate application for this technology is targeted for NASA Langley's HSRL system for aerosol and cloud characterization. This Phase I effort proposes the development of a potassium titanyl phosphate (KTP) waveguide phase modulator for future integration into a PLC. For this innovation, the proposed device is the integration of a waveguide-based frequency doubler and phase modulator in a single, fiber pigtail device that will be capable of efficient second harmonic generation of 1,064-nm light and subsequent phase modulation of the 532 nm light at 250 MHz, providing a properly spectrally formatted beam for HSRL s seed laser locking system. Fabrication of the integrated PLC chip for NASA Langley, planned for

  4. Fuel quality control: Five years of activity in laboratories

    International Nuclear Information System (INIS)

    A description of how ENEL (Italian National Electricity Board) carries out the activity of fuel quality control is given, and the results of the Round Robin circuit which has been operating for five years in laboratories regulary performing the control analyses of these products are reported. The laboratories taking part in the Round Robin circuit are 41 (out of which 35 are ENEL laboratories and 6 are owned by external companies) and they are situated throughout Italy; the controlled parameters are the following: heat of combustion (PCS), sulphur (S), vanadium (V) and asphaltenes (ASF); the adopted methods are the official ASTM or IP ones. The statistical analysis of the results has permitted, for every parameter, the calculation of the repeatability and the reproducibility which, in most cases, have turned out to be in keeping with the values provided for in the regulations. Among the collateral initiatives promoted in the framework of this Round Robin, the following are reported: preparation of standards of fuel oil with a known content of a sulphur and vanadium; expediting visits to all the ENEL laboratories participating in the RRT; publication of a handbook of the adopted analysis methods (in Italian); definition of guide-lines on the right selection of new automatic equipment

  5. Wiring visual circuits, one eye at a time

    OpenAIRE

    El Danaf, Rana N; Huberman, Andrew D.

    2012-01-01

    A study uses light-gated ion channels to control the activity of neurons in each eye, thereby revealing how the timing of neuronal firing dictates whether visual circuits segregate from one another or stay mixed.

  6. Passive and active RF-microwave circuits course and exercises with solutions

    CERN Document Server

    Jarry, Pierre

    2015-01-01

    Microwave and radiofrequency (RF) circuits play an important role in communication systems. Due to the proliferation of radar, satellite, and mobile wireless systems, there is a need for design methods that can satisfy the ever increasing demand for accuracy, reliability, and fast development times. This book explores the principal elements for receiving and emitting signals between Earth stations, satellites, and RF (mobile phones) in four parts; the theory and realization of couplers, computation and realization of microwave and RF filters, amplifiers and microwave and RF oscillators. Pas

  7. A fuzzy-logic based dual-purpose adaptive circuit for vibration control and energy harvesting using piezoelectric transducer

    Science.gov (United States)

    Liu, Zhe Peng; Li, Qing

    2013-04-01

    Due to their two-way electromechanical coupling effect, piezoelectric transducers can be used to synthesize passive vibration control schemes, e.g., RLC circuit with the integration of inductance and resistance elements that is conceptually similar to damped vibration absorber. Meanwhile, the wide usage of wireless sensors has led to the recent enthusiasm of developing piezoelectric-based energy harvesting devices that can convert ambient vibratory energy into useful electrical energy. It can be shown that the integration of circuitry elements such as resistance and inductance can benefit the energy harvesting capability. Here we explore a dual-purpose circuit that can facilitate simultaneous vibration suppression and energy harvesting. It is worth noting that the goal of vibration suppression and the goal of energy harvesting may not always complement each other. That is, the maximization of vibration suppression doesn't necessarily lead to the maximization of energy harvesting, and vice versa. In this research, we develop a fuzzy-logic based algorithm to decide the proper selection of circuitry elements to balance between the two goals. As the circuitry elements can be online tuned, this research yields an adaptive circuitry concept for the effective manipulation of system energy and vibration suppression. Comprehensive analyses are carried out to demonstrate the concept and operation.

  8. Active interaction control for civil structures

    OpenAIRE

    Wang, Luo-Jia

    1997-01-01

    This thesis presents a civil engineering approach to active control for civil structures. The proposed control technique, termed Active Interaction Control (AIC), utilizes dynamic interactions between different structures, or components of the same structure, to reduce the resonance response of the controlled or primary structure under earthquake excitations. The primary control objective of AIC is to minimize the maximum story drift of the primary structure. This is accomplished by timing th...

  9. Cooperative Control Method of Active and Semiactive Control: New Framework for Vibration Control

    OpenAIRE

    Kazuhiko Hiramoto

    2014-01-01

    A new control design framework for vibration control, the cooperative control of active and semiactive control, is proposed in the paper. In the cooperative control, a structural system having both of an actuator and a semiactive control device, for example, MR damper and so forth, is defined as the control object. In the proposed control approach, the higher control performance is aimed by the cooperative control between the active control with the actuator and the semiactive control with th...

  10. Vector Control of Three-Phase Induction Motor with Two Stator Phases Open-Circuit

    OpenAIRE

    Seyed Hesam Asgari; Mohammad Jannati; Tole Sutikno; Nik Rumzi Nik Idris

    2015-01-01

    Variable frequency drives are used to provide reliable dynamic systems and significant reduction in usage of energy and costs of the induction motors. Modeling and control of faulty or an unbalanced three-phase induction motor is obviously different from healthy three-phase induction motor. Using conventional vector control techniques such as Field-Oriented Control (FOC) for faulty three-phase induction motor, results in a significant torque and speed oscillation. This research presented a no...

  11. Semi-active vibration control based on unsymmetrical synchronized switch damping: Analysis and experimental validation of control performance

    Science.gov (United States)

    Ji, Hongli; Qiu, Jinhao; Cheng, Li; Nie, Hong

    2016-05-01

    In semi-active synchronized switch damping (SSD) approaches for structural vibration control, the damping effect is achieved by properly switching the voltage on the piezoelectric actuators. Unsymmetrical SSD switch circuit has been designed in the previous paper to increase the effective voltage range on the PZT actuator for improvement of the control performance. In this study, analysis and experimental validation of control performance of a synchronized switch damping system based on the unsymmetrical switch circuit are carried out. First the model of an unsymmetrical SSD system is presented and the working principle is introduced. The general expression of the switched voltage on the piezoelectric actuator is derived. Based on its periodicity in steady-state control, the harmonic components of the actuator voltage are derived using Fourier series expansion. Next, the displacement response of the system is derived under combined actions of the excitation and switched voltage. Finally, a setup of a flexible beam with unsymmetrical switch circuit is used to demonstrate the control performance under different voltage sources and to verify the theoretical results. The results show that the control performance mainly depends on the voltage range on the PZT. A higher effective voltage range can be generated in unsymmetrical SSDV than in symmetrical SSDV and better control performance can be achieved at the same negative actuator voltage. The unsymmetrical SSDV makes better utilization of the actuator capability.

  12. Genetic circuit design automation.

    Science.gov (United States)

    Nielsen, Alec A K; Der, Bryan S; Shin, Jonghyeon; Vaidyanathan, Prashant; Paralanov, Vanya; Strychalski, Elizabeth A; Ross, David; Densmore, Douglas; Voigt, Christopher A

    2016-04-01

    Computation can be performed in living cells by DNA-encoded circuits that process sensory information and control biological functions. Their construction is time-intensive, requiring manual part assembly and balancing of regulator expression. We describe a design environment, Cello, in which a user writes Verilog code that is automatically transformed into a DNA sequence. Algorithms build a circuit diagram, assign and connect gates, and simulate performance. Reliable circuit design requires the insulation of gates from genetic context, so that they function identically when used in different circuits. We used Cello to design 60 circuits forEscherichia coli(880,000 base pairs of DNA), for which each DNA sequence was built as predicted by the software with no additional tuning. Of these, 45 circuits performed correctly in every output state (up to 10 regulators and 55 parts), and across all circuits 92% of the output states functioned as predicted. Design automation simplifies the incorporation of genetic circuits into biotechnology projects that require decision-making, control, sensing, or spatial organization. PMID:27034378

  13. Single-Phase Single-Stage PV-Grid System Using VSI Based on Simple Control Circuit

    Directory of Open Access Journals (Sweden)

    Slamet Riyadi

    2012-12-01

    Full Text Available Integrating electric energy generated by PV with utilities has been developed. Some of these using two-stage converters and the others using single stage converters. For systems with two-stage converters, the first stage converter acts as a MPPT to maximize power generated by PV and the second stage is used as an interface to the utilities. In the single-stage system, an inverter is used for both function. In this paper, PV-Grid System using a single-stage Voltage Source Inverter is proposed. The simple control circuit to make PV generate maximum power and keeping power equilibrium between PV and inverter output power is used. To verify the analysis, simulations are done.

  14. Stable level and phase control circuits for high power VHF transmitters for RIB applications

    International Nuclear Information System (INIS)

    For most applications it is required that the output power level and insertion phase of a high power transmitter remain unchanged against ambient temperature variation and power supply fluctuations. Design schemes for a stable level controller and a phase controller for use in a VHF transmitter that has been indigenously developed for RIB application at VECC is presented in this paper. (author)

  15. Optoelectronics circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Optoelectronics Circuits Manual covers the basic principles and characteristics of the best known types of optoelectronic devices, as well as the practical applications of many of these optoelectronic devices. The book describes LED display circuits and LED dot- and bar-graph circuits and discusses the applications of seven-segment displays, light-sensitive devices, optocouplers, and a variety of brightness control techniques. The text also tackles infrared light-beam alarms and multichannel remote control systems. The book provides practical user information and circuitry and illustrations.

  16. THE FUZZY LOGIC BASED POWER INJECTION INTO ROTOR CIRCUIT FOR INSTANTANEOUS HIGH TORQUE AND SPEED CONTROL IN INDUCTION MACHINES

    Directory of Open Access Journals (Sweden)

    Selami KESLER

    2009-01-01

    Full Text Available The power flow of the rotor circuit is controlled by different methods in induction machines used for producing high torque in applications involved great power and constant output power with constant frequency in wind turbines. The voltage with slip frequency can be applied on rotor windings to produce controlled high torque and obtain optimal power factor and speed control. In this study, firstly, the dynamic effects of the voltage applying on rotor windings through the rings in slip-ring induction machines are researched and undesirable aspects of the method are exposed with simulations supported by experiments. Afterwards, a fuzzy logic based inverter model on rotor side is proposed with a view to improving the dynamic effects, controlling high torque producing and adjusting machine speed in instantaneous forced conditions. For the simulation model of the system in which the stator side is directly connected to the grid in steady state operation, a C/C++ algorithm is developed and the results obtained for different load conditions are discussed.

  17. Microglial control of neuronal activity

    Directory of Open Access Journals (Sweden)

    Catherine eBéchade

    2013-03-01

    Full Text Available Fine-tuning of neuronal activity was thought to be a neuron-autonomous mechanism until the discovery that astrocytes are active players of synaptic transmission. The involvement of astrocytes has changed our understanding of the roles of non-neuronal cells and shed new light on the regulation of neuronal activity. Microglial cells are the macrophages of the brain and they have been mostly investigated as immune cells. However recent data discussed in this review support the notion that, similarly to astrocytes, microglia are involved in the regulation of neuronal activity. For instance, in most, if not all, brain pathologies a strong temporal correlation has long been known to exist between the pathological activation of microglia and dysfunction of neuronal activity. Recent studies have convincingly shown that alteration of microglial function is responsible for pathological neuronal activity. This causal relationship has also been demonstrated in mice bearing loss-of-function mutations in genes specifically expressed by microglia. In addition to these long-term regulations of neuronal activity, recent data show that microglia can also rapidly regulate neuronal activity, thereby acting as partners of neurotransmission.

  18. Analytical criteria for local activity of CNN with five state variables and application to Hyper-chaos synchronization Chua's circuit

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The analytic criteria for the local activity theory in one-port cellular neural network (CNN) with five local state variables are presented. The application to a Hyper-chaos synchronization Chua's circuit (HCSCC) CNN with 1125 variables is studied. The bifurcation diagrams of the HCSCC CNN show that they are slightly different from the smoothed CNN with one or two ports and four state variables calculated earlier. The evolution of the patterns of the state variables of the HCSCC CNN is stimulated. Oscillatory patterns, chaotic patterns, convergent or divergent patterns may emerge if the selected cell parameters are located in the locally active domains but nearby or in the edge of chaos domain.

  19. Vibration control of active structures an introduction

    CERN Document Server

    Preumont, Andre

    2002-01-01

    This text is an introduction to the dynamics of active structures and to the feedback control of lightly damped flexible structures. The emphasis is placed on basic issues and simple control strategies that work.

  20. Developing Internal Controls through Activities

    Science.gov (United States)

    Barnes, F. Herbert

    2009-01-01

    Life events can include the Tuesday afternoon cooking class with the group worker or the Saturday afternoon football game, but in the sense that Fritz Redl thought of them, these activities are only threads in a fabric of living that includes all the elements of daily life: playing, working, school-based learning, learning through activities,…

  1. Relationship between Voltage-current Curve and Circuit Frequency of an Active Memristor%有源忆阻器伏安曲线与电路频率之间的关系

    Institute of Scientific and Technical Information of China (English)

    王殿学

    2015-01-01

    忆阻器是具有记忆特性非线性电阻器,是现实的第四种基本二端电路元件。文章以光滑三次型非线型函数描述的有源磁控忆阻器模型为例,利用Multisim计算机仿真软件,进一步研究有源忆阻器伏安曲线与电路频率之间关系,讨论有源忆阻器输入电流的突变特性。结果表明:由光滑三次型非线型函数的有源磁控忆阻器模型构成的电路具有边界效应,电流具有突变特性。%With the active magnetic control memristor model described with smooth thrice non-linear function as an example, the relationship between the voltage-current curve and circuit frequency of an active memristor was further studied with Multisim.The saltation characteristic of input current of an active memristor is also discussed. The result shows that there is boundary effect in the circuit constituted with the active magnetic control model de-scribed with smooth thrice non-linear function.The current of the circuit has saltation characteristic.

  2. Control strategy and hardware implementation for DC–DC boost power circuit based on proportional–integral compensator for high voltage application

    Directory of Open Access Journals (Sweden)

    Sanjeevikumar Padmanaban

    2015-06-01

    Full Text Available For high-voltage (HV applications, the designers mostly prefer the classical DC–DC boost converter. However, it lacks due to the limitation of the output voltage by the gain transfer ratio, decreased efficiency and its requirement of two sensors for feedback signals, which creates complex control scheme with increased overall cost. Furthermore, the output voltage and efficiency are reduced due to the self-parasitic behavior of power circuit components. To overcome these drawbacks, this manuscript provides, the theoretical development and hardware implementation of DC–DC step-up (boost power converter circuit for obtaining extra output-voltage high-performance. The proposed circuit substantially improves the high output-voltage by voltage-lift technology with a closed loop proportional–integral controller. This complete numerical model of the converter circuit including closed loop P-I controller is developed in simulation (Matlab/Simulink software and the hardware prototype model is implemented with digital signal processor (DSP TMS320F2812. A detailed performance analysis was carried out under both line and load regulation conditions. Numerical simulation and its verification results provided in this paper, prove the good agreement of the circuit with theoretical background.

  3. Operative and postoperative control of variations in characteristics of physicochemical processes in NPP circuits

    International Nuclear Information System (INIS)

    Based on actual data obtained from operative chemical monitoring in operating NPPs, the authors show the use of some probability diagnosis methods in practical applications such as identification of anomalies of the water chemistry condition, specifically, in the following: detecting violation of control limits a priori determined for the water chemistry parameters, using the control card method; construction of detectors for identifying probably (statistically) significant stepwise changes in the current arithmetical mean of the water chemistry parametric values; identifying successive changes in the behavior of robust estimators of the monitored parameters values; construction of robust linear regression prognostic models for dynamic changes in the monitored parameters values; correlation analysis of time series formed from the measured data on the water chemistry connected parameters (which are lumped (concentrated at one control point) and/or distributed along the coolant path). (author)

  4. Development of novel control strategy for multiple circuit, roof top bus air conditioning system in hot humid countries

    International Nuclear Information System (INIS)

    A novel control strategy to improve energy efficiency and to enhance passengers' thermal comfort of a new roof top bus multiple circuit air conditioning (AC) system operating on partial load conditions is presented. A novel strategy for automatic control of the AC system was developed based on numerous experimental test runs at various operating conditions, taking into account energy saving and thermal comfort without sacrificing the proper cycling rate of the system compressor. For this task, more than 50 test runs were conducted at different set point temperatures of 21, 22 and 23 deg. C. Fanger's method was used to evaluate passenger thermal comfort, and the system energy consumption was also calculated. A performance comparison between that of the conventional AC system and that of the newly developed one has been conducted. The comparison revealed that the adopted control strategy introduces significant improvements in terms of thermal comfort and energy saving on various partial load conditions. Potential energy saving of up to 31.6% could be achieved. This results in a short payback period of 17 months. It was found from the economic analysis that the new system is able to save approximately 20.0% of the life cycle cost

  5. Neurotrophins and spinal circuit function

    OpenAIRE

    Lorne M. Mendell

    2014-01-01

    Work early in the last century emphasized the stereotyped activity of spinal circuits based on studies of reflexes. However, the last several decades have focused on the plasticity of these spinal circuits. These considerations began with studies of the effects of monoamines on descending and reflex circuits. In recent years new classes of compounds called growth factors that are found in peripheral nerves and the spinal cord have been shown to affect circuit behavior in the spinal cord. In t...

  6. A Hybrid Circuit for Spoof Surface Plasmons and Spatial Waveguide Modes to Reach Controllable Band-Pass Filters

    OpenAIRE

    Qian Zhang; Hao Chi Zhang; Han Wu; Tie Jun Cui

    2015-01-01

    We propose a hybrid circuit for spoof surface plasmon polaritons (SPPs) and spatial waveguide modes to develop new microwave devices. The hybrid circuit includes a spoof SPP waveguide made of two anti-symmetric corrugated metallic strips and a traditional substrate integrated waveguide (SIW). From dispersion relations, we show that the electromagnetic waves only can propagate through the hybrid circuit when the operating frequency is less than the cut-off frequency of the SPP waveguide and gr...

  7. Design motor control system of the main circuit and driver circuit%电机控制系统主电路及驱动电路的设计

    Institute of Scientific and Technical Information of China (English)

    阴丽华; 曾显恒

    2014-01-01

    Motor body chosen in this article brushless DC motor using three phase windings star connected while power device is composed of an inverter bridge circuit. The article describes the control system hardware circuit design process. In EasyARM2100 development board for the core of the control unit, the main circuit and the drive unit line described, and hardware design also made corresponding explanation.%本文中选用的无刷直流电动机的电机本体采用星形连接的三相对称绕组,同时功率器件组成的逆变器为桥式电路。文章主要叙述了控制系统的硬件电路设计过程。以EasyARM2100开发板为核心的控制单元,主电路及驱动单元行了阐述,并对硬件设计也作出了相应的解释。

  8. Cascaded active silicon microresonator array cross-connect circuits for WDM networks-on-chip

    Science.gov (United States)

    Poon, Andrew W.; Xu, Fang; Luo, Xianshu

    2008-02-01

    We propose a design of an optical switch on a silicon chip comprising a 5 × 5 array of cascaded waveguide-crossing-coupled microring resonator-based switches for photonic networks-on-chip applications. We adopt our recently demonstrated design of multimode-interference (MMI)-based wire waveguide crossings, instead of conventional plain waveguide crossings, for the merits of low loss and low crosstalk. The microring resonator is integrated with a lateral p-i-n diode for carrier-injection-based GHz-speed on-off switching. All 25 microring resonators are assumed to be identical within a relatively wide resonance line width. The optical circuit switch can employ a single wavelength channel or multiple wavelength channels that are spaced by the microring resonator free spectral range. We analyze the potential performance of the proposed photonic network in terms of (i) light path cross-connections loss budget, and (ii) DC on-off power consumption for establishing a light path. As a proof-of-concept, our initial experiments on cascaded passive silicon MMI-crossing-coupled microring resonators demonstrate 3.6-Gbit/s non-return-to-zero data transmissions at on- and off-resonance wavelengths.

  9. Control system for the feed of pressurized fluid in a hydraulic circuit as a function of the state of the locking or unlocking of two mechanical organs

    International Nuclear Information System (INIS)

    The control system comprises two hydraulic cylinders of which rods are integral with the mechanical organs. The piston of the first cylinder separates the chamber of this one in two parts. The piston of the second cylinder separates its chamber in three parts. The inlet chamber of the two cylinders are connected to pressurized fluid feed pipes, and the outlet chambers to a depressurization pipe. According to the position of the piston depending itself on the state of locking or unlocking of the rods, an interconnection pipe and a feed pipe of the pressurized fluid hydraulic circuit communicate with a chamber or another one. The feed of the hydraulic circuit is possible only the two rods are unlocked. The invention applies more particularly to the feed of the control circuit of an emergency seal of the primary pump of a pressurized water nuclear reactor

  10. 基于忆阻器的自动增益控制电路设计%Design of Automatic Gain Control Circuit Based on Memristor

    Institute of Scientific and Technical Information of China (English)

    王勤; 甘朝晖; 段宗胜

    2013-01-01

    忆阻器被认为是除了电阻、电容、电感之外的第四个基本电路元件,它是一种非线性二端无源器件,具有“记忆”功能.忆阻器在众多领域中具有巨大的应用潜力,有望推动整个电路理论的变革.介绍了一种改进的忆阻器SPICE模型,在此基础上,设计了一种基于忆阻器的自动增益控制电路.通过SPICE对电路进行仿真,证明该设计是可行的,完全实现了增益的自动控制.%Memristor is considered as the forth basic circuit element besides resistor, capacitor and inductor. It is a two-terminal non-linear passive component with memory function. Memristors have great potential applications in many fields, and it is expected to change the theory of circuit greatly. An improved memristor model was presented and an automatic gain control (AGC) circuit was designed based on memristor. The proposed circuit was simulated with SPICE. Simulation results showed that the circuit could fully realize automatic gain control.

  11. Controllable V-Shape Multi-Scroll Butterfly Attractor: System and Circuit Implementation

    KAUST Repository

    Zidan, Mohammed A.

    2012-07-23

    In this paper, a new controllable V-shape multiscroll attractor is presented, where a variety of symmetrical and unsymmetrical attractors with a variable number of scrolls can be controlled using new staircase nonlinear function and the parameters of the system. This attractor can be used to generate random signals with a variety of symbol distribution. Digital implementation of the proposed generator is also presented using a Xilinx Virtex® 4 Field Programmable Gate Array and experimental results are provided. The digital realization easily fits into a small area (<1.5% of the total area) and expresses a high throughput (4.3 Gbit/sec per state variable). © 2012 World Scientific Publishing Company.

  12. Research on Multi Position and Parallel Detection Device for Universal Circuit Breaker Controller

    Directory of Open Access Journals (Sweden)

    Meng Xiang Fei

    2016-01-01

    Full Text Available This paper introduces a design scheme of the residual current electrical fire monitoring detector performance test system based on virtual instrument technology. In order to test different current specifications monitor detector compatiblly,the system combines virtual instrument technology and computer control technology to improve the accuracy of output current of the current generator with electric voltage compensation technology and the way of closed-loop control ,and designs two sets of different size and the same type of pneumatic fixture to solve the connection of different specifications monitoring detector, software design adopts layered structure and the method based on configuration files, to better satisfy all kinds of test requirements for different products. Practical application shows that the system has the testing results of accurate, high efficiency and convenient operation.

  13. The use of test structures for reliability prediction and process control of integrated circuits and photovoltaics

    Science.gov (United States)

    Trachtenberg, I.

    How a reliability model might be developed with new data from accelerated stress testing, failure mechanisms, process control monitoring, and test structure evaluations is illustrated. The effects of the acceleration of temperature on operating life is discussed. Test structures that will further accelerate the failure rate are discussed. Corrosion testing is addressed. The uncoated structure is encapsulated in a variety of mold compounds and subjected to pressure-cooker testing.

  14. Contribution on Control Strategies of Flow-On-Demand Hydraulic Circuits

    OpenAIRE

    Scherer, Martin; Geimer, Marcus [Hrsg.; Weiß, Björn

    2013-01-01

    The development of an innovative flow-on-demand electrohydraulic system for mobile forestry cranes is described in the present paper. To overcome functional principle related weaknesses of conventional hydraulic-mechanical Load-Sensing systems, this work breaks up the control pressure difference related dependence of the delivered oil flow. Rather the swiveling angle of the displacement pump is calculated by summing up the single consumer oil flows corresponding to the velocity requests of th...

  15. Feasibility Study of Correcting Circuit Scheme for Automatic Control System of Total Air in Boiler

    Directory of Open Access Journals (Sweden)

    V. Nazarov

    2014-09-01

    Full Text Available The paper contains results of investigations on dynamic characteristics automatic control system (ACS for total air consumption (TAC in a boiler with corrections for О2 and СО. From transition process point of view the ACS TAC with correction for СО is considered as the most optimum one as with disturbance attack on fuel expenditure so discharging beyond boiler furnace.

  16. A prototype expert system 'SMART' for water chemistry control in reactor water circuits

    International Nuclear Information System (INIS)

    The operational safety of a power plant depends mainly on the material compatibility of the system materials with the environment. However, for an operating plant, the material is almost fixed and hence one can improve the safety by controlling the surrounding environment. From the economy point of view, the plant availability factor as well as plant life extension (PLEX) are important considerations and these necessitate a systematic approach for continuous parametric monitoring, rapid data analysis and diagnosis for controlling the water chemistry regime. A prototype expert system 'SMART' was developed in BASIC language. The expert system consists of four modules. The DATA HANDLER module controls all the data handling functions and graphical display of the data parameters. It also generates weekly and monthly reports of the water chemistry data. The DATA INTERPRETER module compares the experimental data with the theoretically calculated values and predicts the presence of impurity ingress in the system. The CHEMISTRY EXPERT contains the knowledge base about the various sub-systems. All the water chemistry specifications are translated in the form of IF... THEN.. rules and are stored in this module. The expert system inferences with the forward chain reasoning mechanism to identify the diagnostic parameters by consulting the knowledge base and applying the appropriate rules. The ACTION EXPERT module collects all the diagnostic parameters and suggests the operator, the remedial actions/counter measures that should be taken immediately. This rule based system can be expanded to accommodate different water chemistry regimes. (author)

  17. Striatal plasticity and basal ganglia circuit function.

    Science.gov (United States)

    Kreitzer, Anatol C; Malenka, Robert C

    2008-11-26

    The dorsal striatum, which consists of the caudate and putamen, is the gateway to the basal ganglia. It receives convergent excitatory afferents from cortex and thalamus and forms the origin of the direct and indirect pathways, which are distinct basal ganglia circuits involved in motor control. It is also a major site of activity-dependent synaptic plasticity. Striatal plasticity alters the transfer of information throughout basal ganglia circuits and may represent a key neural substrate for adaptive motor control and procedural memory. Here, we review current understanding of synaptic plasticity in the striatum and its role in the physiology and pathophysiology of basal ganglia function. PMID:19038213

  18. Control strategy with minimal controller reconfiguration of fault tolerant polyphase PMSMdrives under open circuit fault of one phase

    OpenAIRE

    Baudart, François; Dehez, Bruno; Labrique, Francis; Matagne, Ernest; Telteu, Dan; Alexandre, Paul; 19th International Conference on Electrical Machines (ICEM 2010)

    2010-01-01

    Segment polyphase motors gain interest in applications requiring high performance and high reliability due to their high fault tolerance. This paper sums up the generalization of the vector control strategy of such motor and presents a method to adapt with a minimal reconfiguration the control strategy in the case of an open phase failure. Simulations results validate the method.

  19. Local GABA Circuit Control of Experience-Dependent Plasticity in Developing Visual Cortex

    OpenAIRE

    Hensch, Takao K.; Fagiolini, Michela; Mataga, Nobuko; Stryker, Michael P.; Baekkeskov, Steinunn; Kash, Shera F.

    1998-01-01

    Sensory experience in early life shapes the mammalian brain. An impairment in the activity-dependent refinement of functional connections within developing visual cortex was identified here in a mouse model. Gene-targeted disruption of one isoform of glutamic acid decarboxylase prevented the competitive loss of responsiveness to an eye briefly deprived of vision, without affecting cooperative mechanisms of synapse modification in vitro. Selective, use-dependent enhancement of fast intracortic...

  20. Large-scale planar lightwave circuits

    Science.gov (United States)

    Bidnyk, Serge; Zhang, Hua; Pearson, Matt; Balakrishnan, Ashok

    2011-01-01

    By leveraging advanced wafer processing and flip-chip bonding techniques, we have succeeded in hybrid integrating a myriad of active optical components, including photodetectors and laser diodes, with our planar lightwave circuit (PLC) platform. We have combined hybrid integration of active components with monolithic integration of other critical functions, such as diffraction gratings, on-chip mirrors, mode-converters, and thermo-optic elements. Further process development has led to the integration of polarization controlling functionality. Most recently, all these technological advancements have been combined to create large-scale planar lightwave circuits that comprise hundreds of optical elements integrated on chips less than a square inch in size.

  1. Circuit analysis with Multisim

    CERN Document Server

    Baez-Lopez, David

    2011-01-01

    This book is concerned with circuit simulation using National Instruments Multisim. It focuses on the use and comprehension of the working techniques for electrical and electronic circuit simulation. The first chapters are devoted to basic circuit analysis.It starts by describing in detail how to perform a DC analysis using only resistors and independent and controlled sources. Then, it introduces capacitors and inductors to make a transient analysis. In the case of transient analysis, it is possible to have an initial condition either in the capacitor voltage or in the inductor current, or bo

  2. A fly-wheel drive with controlled-torque clutch for a reactors cooling circuit pumps

    International Nuclear Information System (INIS)

    After a theoretical study on the slowing down of a centrifugal pump, the motion equations have been checked by means of experimental tests. In order to have important slowing down times (which is the case of the cooling pumps of a research reactor) it is necessary to add a fly-wheel. To prevent troubles when starting, a block pump-fly-wheel with clutch under controlled torque was developed. It is so possible to start the fly-wheel progressively without increasing too much power of the driving motor. (author)

  3. Cryogenic Pound Circuits for Cryogenic Sapphire Oscillators

    Science.gov (United States)

    Dick, G. John; Wang, Rabi

    2006-01-01

    Two modern cryogenic variants of the Pound circuit have been devised to increase the frequency stability of microwave oscillators that include cryogenic sapphire-filled cavity resonators. The original Pound circuit is a microwave frequency discriminator that provides feedback to stabilize a voltage-controlled microwave oscillator with respect to an associated cavity resonator. In the present cryogenic Pound circuits, the active microwave devices are implemented by use of state-of-the-art commercially available tunnel diodes that exhibit low flicker noise (required for high frequency stability) and function well at low temperatures and at frequencies up to several tens of gigahertz. While tunnel diodes are inherently operable as amplitude detectors and amplitude modulators, they cannot, by themselves, induce significant phase modulation. Therefore, each of the present cryogenic Pound circuits includes passive circuitry that transforms the AM into the required PM. Each circuit also contains an AM detector that is used to sample the microwave signal at the input terminal of the high-Q resonator for the purpose of verifying the desired AM null at this point. Finally, each circuit contains a Pound signal detector that puts out a signal, at the modulation frequency, having an amplitude proportional to the frequency error in the input signal. High frequency stability is obtained by processing this output signal into feedback to a voltage-controlled oscillator to continuously correct the frequency error in the input signal.

  4. SLIDING MODE CONTROL FOR ACTIVE AUTOMOBILE SUSPENSIONS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Nonlinear control methods are presented based on theory of sliding mode control (SMC) or variable structure control (VSC) for application to active automobile suspensions. Requirements of reducing manufacturing cost and energy consumption of the active suspension system may be satisfiedby reasonable design of the sliding surface and hydraulic servo system. Emphasis is placed on the study of the discrete sliding mode control method (DSMC) applicable for a new sort of speed on-off solenoid valves of anti-dust capability and low price. Robustness and effectiveness of the feedback linearized controller in typical road conditions are demonstrated by numerical results fora quarter-car suspension model.

  5. Modelling of piezoelectric actuator dynamics for active structural control

    Science.gov (United States)

    Hagood, Nesbitt W.; Chung, Walter H.; Von Flotow, Andreas

    1990-01-01

    The paper models the effects of dynamic coupling between a structure and an electrical network through the piezoelectric effect. The coupled equations of motion of an arbitrary elastic structure with piezoelectric elements and passive electronics are derived. State space models are developed for three important cases: direct voltage driven electrodes, direct charge driven electrodes, and an indirect drive case where the piezoelectric electrodes are connected to an arbitrary electrical circuit with embedded voltage and current sources. The equations are applied to the case of a cantilevered beam with surface mounted piezoceramics and indirect voltage and current drive. The theoretical derivations are validated experimentally on an actively controlled cantilevered beam test article with indirect voltage drive.

  6. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

    Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

  7. High performance of PbSe/PbS core/shell quantum dot heterojunction solar cells: short circuit current enhancement without the loss of open circuit voltage by shell thickness control

    Science.gov (United States)

    Choi, Hyekyoung; Song, Jung Hoon; Jang, Jihoon; Mai, Xuan Dung; Kim, Sungwoo; Jeong, Sohee

    2015-10-01

    We fabricated heterojunction solar cells with PbSe/PbS core shell quantum dots and studied the precisely controlled PbS shell thickness dependency in terms of optical properties, electronic structure, and solar cell performances. When the PbS shell thickness increases, the short circuit current density (JSC) increases from 6.4 to 11.8 mA cm-2 and the fill factor (FF) enhances from 30 to 49% while the open circuit voltage (VOC) remains unchanged at 0.46 V even with the decreased effective band gap. We found that the Fermi level and the valence band maximum level remain unchanged in both the PbSe core and PbSe/PbS core/shell with a less than 1 nm thick PbS shell as probed via ultraviolet photoelectron spectroscopy (UPS). The PbS shell reduces their surface trap density as confirmed by relative quantum yield measurements. Consequently, PbS shell formation on the PbSe core mitigates the trade-off relationship between the open circuit voltage and the short circuit current density. Finally, under the optimized conditions, the PbSe core with a 0.9 nm thick shell yielded a power conversion efficiency of 6.5% under AM 1.5.We fabricated heterojunction solar cells with PbSe/PbS core shell quantum dots and studied the precisely controlled PbS shell thickness dependency in terms of optical properties, electronic structure, and solar cell performances. When the PbS shell thickness increases, the short circuit current density (JSC) increases from 6.4 to 11.8 mA cm-2 and the fill factor (FF) enhances from 30 to 49% while the open circuit voltage (VOC) remains unchanged at 0.46 V even with the decreased effective band gap. We found that the Fermi level and the valence band maximum level remain unchanged in both the PbSe core and PbSe/PbS core/shell with a less than 1 nm thick PbS shell as probed via ultraviolet photoelectron spectroscopy (UPS). The PbS shell reduces their surface trap density as confirmed by relative quantum yield measurements. Consequently, PbS shell formation on

  8. A robust predictive current controller for healthy and open-circuit faulty conditions of five-phase BLDC drives applicable for wind generators and electric vehicles

    International Nuclear Information System (INIS)

    Highlights: • Model predictive deadbeat control of generator stator phase currents. • Fault tolerant control of five-phase BLDC generator. • Control of stator phase currents under normal and open-circuit faulty conditions. • MATLAB simulation and experimental verification of proposed control method. • Verification of robustness and fast respond of proposed controlling method. - Abstract: Fault tolerant control of five-phase brushless direct current (BLDC) machines is gaining more importance in high-safety applications such as offshore wind generators and automotive industries. In many applications, traditional controllers (such as PI controllers) are used to control the stator currents under faulty conditions. These controllers have good performance with dc signals. However, in the case of missing one or two of the phases, appropriate reference currents of these machines have oscillatory dynamics both in phase- and synchronous-reference frames. Non-constant nature of these reference values requires the implication of fast current controllers. In this paper, model predictive deadbeat controllers are proposed to control the stator currents of five-phase BLDC machines under normal and faulty conditions. Open circuit fault is considered for both one and two stator phases, and the behaviour of proposed controlling method is evaluated. This evaluation is generally focused on first, sensitivity of proposed controlling method and second, its speed in following reference current values under transient states. Proposed method is simulated and is verified experimentally on a five-phase BLDC drive

  9. MODERNIZATION OF DESIGN AND DESIGN CIRCUITS FOR CONTROL PART OF SPORTS SIMULATOR PNEUMATIC DRIVE

    Directory of Open Access Journals (Sweden)

    I. V. Каchanov

    2014-12-01

    Full Text Available The paper contains justification on application of a pneumatic drive  in various training simulators which are used as for general rehabilitation so for professional training as well for various kinds of sports. Simulator flow diagrams based on pneumatic drive are presented in the paper.A mathematical model has been constructed that makes it possible to determine operational characteristics of the pneumatic drive and select design parameters of simulator elements.As a result of calculating characteristics of the sports simulator pneumatic drive some drawbacks have been revealed in pneumatic equipment. For this very reason an original design of pneumatic control element with improved characteristics has been developed and its flow diagram is given in the paper.

  10. All optical controlled-NOT gate based on an exciton-polariton circuit

    Science.gov (United States)

    Solnyshkov, D. D.; Bleu, O.; Malpuech, G.

    2015-07-01

    We propose an implementation of a CNOT gate for quantum computing based on a patterned microcavity polariton system, which can be manufactured using the modern technological facilities. The qubits are encoded in the spin-coherent polariton states. The structure consists of two wire cavities oriented at 45° with a micropillar between them. The polariton spin rotates due to the Longitudinal-Transverse splitting between polarization eigenstates in the wires. In the pillar, the optically generated circularly polarized polariton macrooccupied state plays the role of the control qubit. Because of the spin-anisotropic polariton interaction, it induces an effective magnetic field along the Z-direction with a sign depending on the qubit value.

  11. Control of stress-induced persistent anxiety by an extra-amygdala septohypothalamic circuit.

    Science.gov (United States)

    Anthony, Todd E; Dee, Nick; Bernard, Amy; Lerchner, Walter; Heintz, Nathaniel; Anderson, David J

    2014-01-30

    The extended amygdala has dominated research on the neural circuitry of fear and anxiety, but the septohippocampal axis also plays an important role. The lateral septum (LS) is thought to suppress fear and anxiety through its outputs to the hypothalamus. However, this structure has not yet been dissected using modern tools. The type 2 CRF receptor (Crfr2) marks a subset of LS neurons whose functional connectivity we have investigated using optogenetics. Crfr2(+) cells include GABAergic projection neurons that connect with the anterior hypothalamus. Surprisingly, we find that these LS outputs enhance stress-induced behavioral measures of anxiety. Furthermore, transient activation of Crfr2(+) neurons promotes, while inhibition suppresses, persistent anxious behaviors. LS Crfr2(+) outputs also positively regulate circulating corticosteroid levels. These data identify a subset of LS projection neurons that promote, rather than suppress, stress-induced behavioral and endocrinological dimensions of persistent anxiety states and provide a cellular point of entry to LS circuitry. PMID:24485458

  12. Operant behavior to obtain palatable food modifies ERK activity in the brain reward circuit.

    Science.gov (United States)

    Guegan, Thomas; Cutando, Laura; Gangarossa, Giuseppe; Santini, Emanuela; Fisone, Gilberto; Martinez, Albert; Valjent, Emmanuel; Maldonado, Rafael; Martin, Miquel

    2013-03-01

    Food palatability produces behavioral modifications that resemble those induced by drugs of abuse. Palatability-induced behavioral changes require both, the activation of the endogenous cannabinoid system, and changes in structural plasticity in neurons of the brain reward pathway. The ERK intracellular pathway is activated by CB1 receptors (CB1-R) and plays a crucial role in neuroplasticity. We investigated the activation of the ERK signaling cascade in the mesocorticolimbic system induced by operant training to obtain highly palatable isocaloric food and the involvement of the CB1-R in these responses. Using immunofluorescence techniques, we analyzed changes in ERK intracellular pathway activation in the mesocorticolimbic system of wild-type and CB1 knockout mice (CB1-/-) trained on an operant paradigm to obtain standard, highly caloric or highly palatable isocaloric food. Operant training for highly palatable isocaloric food, but not for standard or highly caloric food, produced a robust activation of the ERK signaling cascade in the same brain areas where this training modified structural plasticity. These changes induced by the operant training were absent in CB1-/-. We can conclude that the activation of the ERK pathway is associated to the neuroplasticity induced by operant training for highly palatable isocaloric food and might be involved in CB1-R mediated alterations in behavior and structural plasticity. PMID:22580057

  13. Active vibration control of lightweight floor systems

    Science.gov (United States)

    Baader, J.; Fontana, M.

    2016-04-01

    Wide-span and lightweight floors are often prone to structural vibrations due to their low resonance frequency and poor material damping. Their dynamic behaviour can be improved using passive, semi-active or active vibration control devices. The following article proposes a novel method for the controller synthesis for active vibration control. An existing passive TMD (tuned mass damper) is modelled and equipped with an actuator in order to provide more efficient damping. Using an iterative optimization approach under constraints, an optimal controller is found which minimizes a quadratic cost function in frequency domain. A simulation of an existing test bench shows that the active vibration control device is able to provide increased damping compared to the passive TMD.

  14. Ap-let neurons--a peptidergic circuit potentially controlling ecdysial behavior in Drosophila.

    Science.gov (United States)

    Park, Dongkook; Han, Mei; Kim, Young-Cho; Han, Kyung-An; Taghert, Paul H

    2004-05-01

    Here we describe a novel set of peptidergic neurons conserved throughout all developmental stages in the Drosophila central nervous system (CNS). We show that a small complement of 28 apterous-expressing cells (Ap-let neurons) in the ventral nerve cord (VNC) of Drosophila larvae co-express numerous gene products. The products include the neuroendocrine-specific bHLH regulator called Dimmed (Dimm), four neuropeptide biosynthetic enzymes (PC2, Fur1, PAL2, and PHM), and a specific dopamine receptor subtype (dDA1). For the PC2, Fur1, and PAL2 enzymes, and for the dDA1 receptor, this neuronal pattern represents the vast majority of their total expression in the VNC. In addition, while Dimm and PHM are present in the peritracheal Inka cells in larvae, pupae, and adults, Ap, PC2, Fur1, PAL2, and dDA1 are not. PC2, PAL2, and DA1 receptor expression were all controlled by both dimm and ap. Previous genetic analysis of animals deficient in PC2 revealed an abnormal larval ecdysis phenotype. Together, these data support the hypothesis that the small cohort of Ap-let interneurons regulates larval ecdysis behavior by secretion of an unidentified amidated peptide(s). This hypothesis further predicts that the production of the Ap-let neuropeptide(s) is dependent on each of four specific enzymes, and that a certain aspect(s) of its production and/or release is regulated by dopamine input. PMID:15081360

  15. Linear analysis near a steady-state of biochemical networks: control analysis, correlation metrics and circuit theory

    Directory of Open Access Journals (Sweden)

    Qian Hong

    2008-05-01

    Full Text Available Abstract Background: Several approaches, including metabolic control analysis (MCA, flux balance analysis (FBA, correlation metric construction (CMC, and biochemical circuit theory (BCT, have been developed for the quantitative analysis of complex biochemical networks. Here, we present a comprehensive theory of linear analysis for nonequilibrium steady-state (NESS biochemical reaction networks that unites these disparate approaches in a common mathematical framework and thermodynamic basis. Results: In this theory a number of relationships between key matrices are introduced: the matrix A obtained in the standard, linear-dynamic-stability analysis of the steady-state can be decomposed as A = SRT where R and S are directly related to the elasticity-coefficient matrix for the fluxes and chemical potentials in MCA, respectively; the control-coefficients for the fluxes and chemical potentials can be written in terms of RT BS and ST BS respectively where matrix B is the inverse of A; the matrix S is precisely the stoichiometric matrix in FBA; and the matrix eAt plays a central role in CMC. Conclusion: One key finding that emerges from this analysis is that the well-known summation theorems in MCA take different forms depending on whether metabolic steady-state is maintained by flux injection or concentration clamping. We demonstrate that if rate-limiting steps exist in a biochemical pathway, they are the steps with smallest biochemical conductances and largest flux control-coefficients. We hypothesize that biochemical networks for cellular signaling have a different strategy for minimizing energy waste and being efficient than do biochemical networks for biosynthesis. We also discuss the intimate relationship between MCA and biochemical systems analysis (BSA.

  16. Active Control of Fan Noise

    Institute of Scientific and Technical Information of China (English)

    Nobuhiko YAMASAKI; Hirotoshi TAJIMA

    2008-01-01

    In the wake-rotor interaction fan noise, a number of the interacting modes at the blade passing frequency (BPF)and its harmonics are generated which are prescribed by the number of stator and rotor blades etc. In the present study, the dominant mode is tried to be suppressed by the secondary sound from the loudspeaker actuators. One of the novel features of the present system is the adoption of the control board with the Field Programmable Gate Array (FPGA) hardware and the LabVIEW software to synchronize the circumferentially installed loudspeaker actuators with the relative location of rotational blades under arbitrary fan rotational speeds. The experiments were conducted under the conditions of three rotational speeds of 2004, 3150, and 4002 [rpm]. The reduction in the sound pressure level (SPL) was observed for all three rotational speeds. The sound pressure level at the BPF was reduced approximately 13 [dB] for 2004 [rpm] case, but not so large reduction was attained for other cases probably due to the inefficiency of the loudspeaker actuators at high frequencies

  17. Buck-boost converter for simultaneous semi-active vibration control and energy harvesting for electromagnetic regenerative shock absorber

    Science.gov (United States)

    Li, Peng; Zhang, Chongxiao; Kim, Junyoung; Yu, Liangyao; Zuo, Lei

    2014-04-01

    Regenerative semi-active suspensions can capture the previously dissipated vibration energy and convert it to usable electrical energy for powering on-board electronic devices, while achieve both the better ride comfort and improved road handling performance at the same time when certain control is applied. To achieve this objective, the power electronics interface circuit connecting the energy harvester and the electrical loads, which can perform simultaneous vibration control and energy harvesting function is in need. This paper utilized a buck-boost converter for simultaneous semi-active vibration control and energy harvesting with electromagnetic regenerative shock absorber, which utilizes a rotational generator to converter the vibration energy to electricity. It has been found that when the circuit works in discontinuous current mode (DCM), the ratio between the input voltage and current is only related to the duty cycle of the switch pulse width modulation signal. Using this property, the buck-boost converter can be used to perform semi-active vibration control by controlling the load connected between the terminals of the generator in the electromagnetic shock absorber. While performing the vibration control, the circuit always draw current from the shock absorber and the suspension remain dissipative, and the shock absorber takes no additional energy to perform the vibration control. The working principle and dynamics of the circuit has been analyzed and simulations were performed to validate the concept.

  18. Cortico-Basal Ganglia Circuit Function in Psychiatric Disease.

    Science.gov (United States)

    Gunaydin, Lisa A; Kreitzer, Anatol C

    2016-01-01

    Circuit dysfunction models of psychiatric disease posit that pathological behavior results from abnormal patterns of electrical activity in specific cells and circuits in the brain. Many psychiatric disorders are associated with abnormal activity in the prefrontal cortex and in the basal ganglia, a set of subcortical nuclei implicated in cognitive and motor control. Here we discuss the role of the basal ganglia and connected prefrontal regions in the etiology and treatment of obsessive-compulsive disorder, anxiety, and depression, emphasizing mechanistic work in rodent behavioral models to dissect causal cortico-basal ganglia circuits underlying discrete behavioral symptom domains relevant to these complex disorders. PMID:26667072

  19. Independent Control of Active and Reactive Powers of a DFIG Based Wind Energy Conversion System by Vector Control

    Directory of Open Access Journals (Sweden)

    Ibrahim Ahmad A

    2015-03-01

    Full Text Available The paper deals with a design and implementation of a doubly fed induction generator (DFIG wind energy conversion system (WECS connected to the power grid. A back-to-back AC/DC/AC converter is incorporated between the stator and the rotor windings of a DFIG, in order to obtain variable speed operation. The DFIG can be controlled from sub-synchronous speed to super synchronous speed operation. The main objective of the paper is to control the flow of the Active and Reactive powers produced by the DFIG based wind energy conversion system. A vector control strategy with stator flux orientation is applied to both the grid side converter and the rotor side converter for the independent control of Active and reactive powers produced by the DFIG based wind energy conversion system. The system along with its control circuit were simulated in a Matlab/simulink and the results are presented and discussed.

  20. DSP Control of Line Hybrid Active Filter

    DEFF Research Database (Denmark)

    Dan, Stan George; Benjamin, Doniga Daniel; Magureanu, R.;

    2005-01-01

    Active Power Filters have been intensively explored in the past decade. Hybrid active filters inherit the efficiency of passive filters and the improved performance of active filters, and thus constitute a viable improved approach for harmonic compensation. In this paper a parallel hybrid filter...... is studied for current harmonic compensation. The hybrid filter is formed by a single tuned Le filter and a small-rated power active filter, which are directly connected in series without any matching transformer. Thus the required rating of the active filter is much smaller than a conventional standalone...... active filter. Simulation and experimental results obtained in laboratory confirmed the validity and effectiveness of the control....

  1. Manually controlled neutron-activation system

    Science.gov (United States)

    Johns, R. A.; Carothers, G. A.

    1982-01-01

    A manually controlled neutron activation system, the Manual Reactor Activation System, was designed and built and has been operating at one of the Savannah River Plant's production reactors. With this system, samples can be irradiated for up to 24 hours and pneumatically transferred to a shielded repository for decay until their activity is low enough for them to be handled at a radiobench. The Manual Reactor Activation System was built to provide neutron activation of solid waste forms for the Alternative Waste Forms Leach Testing Program. Neutron activation of the bulk sample prior to leaching permits sensitive multielement radiometric analyses of the leachates.

  2. A single lithium-ion battery protection circuit with high reliability and low power consumption

    International Nuclear Information System (INIS)

    A single lithium-ion battery protection circuit with high reliability and low power consumption is proposed. The protection circuit has high reliability because the voltage and current of the battery are controlled in a safe range. The protection circuit can immediately activate a protective function when the voltage and current of the battery are beyond the safe range. In order to reduce the circuit's power consumption, a sleep state control circuit is developed. Additionally, the output frequency of the ring oscillation can be adjusted continuously and precisely by the charging capacitors and the constant-current source. The proposed protection circuit is fabricated in a 0.5 μm mixed-signal CMOS process. The measured reference voltage is 1.19 V, the overvoltage is 4.2 V and the undervoltage is 2.2 V. The total power is about 9 μW. (semiconductor integrated circuits)

  3. Light activated escape circuits : a behavior and neurophysiology lab module using Drosophila optogenetics

    OpenAIRE

    Titlow, Joshua S.; Johnson, Bruce R.; Pulver, Stefan R.

    2015-01-01

    The neural networks that control escape from predators often show very clear relationships between defined sensory inputs and stereotyped motor outputs. This feature provides unique opportunities for researchers, but it also provides novel opportunities for neuroscience educators. Here we introduce new teaching modules using adult Drosophila that have been engineered to express csChrimson, a red-light sensitive channelrhodopsin, in specific sets of neurons and muscles mediating visually guide...

  4. Active Power Filter Using Predicted Current Control

    Czech Academy of Sciences Publication Activity Database

    Xiaojie, Y.; Pivoňka, P.; Valouch, Viktor

    2001-01-01

    Roč. 46, č. 1 (2001), s. 41-50. ISSN 0001-7043 Institutional research plan: CEZ:AV0Z2057903 Keywords : active power filter * control strategy Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  5. Research on a new active power filter topology based on chopper circuit

    OpenAIRE

    Xiaoling, Guo; Jian, Cheng; Bo, Zhang; Jing, Zhang

    2015-01-01

    The active power filter (APF) is attracting more and more attention for its outstanding performance in current and voltage ripple compensation. As modern high-energy accelerators are demanding much more stringent current ripple guideline, the APF is introduced to the magnet power supply (MPS) in accelerator system. However, the conventional APF has a lot of shortages and drawbacks due to its traditional topology, such as complex structure, nonadjustable working voltage, requirement of power s...

  6. Alterations in Neuronal Activity in Basal Ganglia-Thalamocortical Circuits in the Parkinsonian State

    Directory of Open Access Journals (Sweden)

    Adriana Galvan

    2015-02-01

    Full Text Available In patients with Parkinson’s disease and in animal models of this disorder, neurons in the basal ganglia and related regions in thalamus and cortex show changes that can be recorded by using electrophysiologic single-cell recording techniques, including altered firing rates and patterns, pathologic oscillatory activity and increased inter-neuronal synchronization. In addition, changes in synaptic potentials or in the joint spiking activities of populations of neurons can be monitored as alterations in local field potentials, electroencephalograms or electrocorticograms. Most of the mentioned electrophysiologic changes are probably related to the degeneration of diencephalic dopaminergic neurons, leading to dopamine loss in the striatum and other basal ganglia nuclei, although degeneration of non-dopaminergic cell groups may also have a role. The altered electrical activity of the basal ganglia and associated nuclei may contribute to some of the motor signs of the disease. We here review the current knowledge of the electrophysiologic changes at the single cell level, the level of local populations of neural elements, and the level of the entire basal ganglia-thalamocortical network in parkinsonism, and discuss the possible use of this information to optimize treatment approaches to Parkinson’s disease, such as deep brain stimulation therapy.

  7. Active Noise Control in Propeller Aircraft

    OpenAIRE

    Johansson, Sven; Claesson, Ingvar

    2001-01-01

    A noisy environment dominated by low frequency noise can often be improved through the use of active noise control. This situation arises naturally in propeller aircraft where the propellers induce periodic low frequency noise inside the cabin. The cabin noise is typically rather high, and the passenger flight comfort could be improved considerably if this level were significantly reduced. This paper addresses same design aspects for multiple-reference active noise control systems based on th...

  8. Breathing and Vocal Control: The Respiratory System as both a Driver and Target of Telencephalic Vocal Motor Circuits in Songbirds

    OpenAIRE

    Schmidt, Marc F.; McLean, Judith; Goller, Franz

    2011-01-01

    The production of vocalizations is intimately linked to the respiratory system. Despite our understanding of neural circuits that generate normal respiratory patterns, very little is understood regarding how these ponto-medullary circuits become engaged during vocal production. Songbirds offer a potentially powerful model system for addressing this relationship. Songs dramatically alter the respiratory pattern in ways that are often highly predictable and songbirds have a specialized telencep...

  9. Bismuth Ferrite for Active Control of Surface Plasmon Polariton Modes

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Zhukovsky, Sergei; Lavrinenko, Andrei

    We propose and investigate several layouts of m etal-insulator-metal waveguide with active core which can be utilized for dynamic switching in photonic integrated circuits. The active material, bismuth ferrite (BiFeO3), is sandwiched between metal plates and changes i ts refractive index through ...

  10. Bismuth Ferrite for Active Control of Surface Plasmon Polariton Modes

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Zhukovsky, Sergei; Lavrinenko, Andrei

    2014-01-01

    We propose and investigate several layouts of m etal-insulator-metal waveguide with active core which can be utilized for dynamic switching in photonic integrated circuits. The active material, bismuth ferrite (BiFeO3), is sandwiched between metal plates and changes i ts refractive index through...

  11. Semi-active control of dynamically excited structures using active interaction control

    OpenAIRE

    Zhang, Yunfeng

    2001-01-01

    This thesis presents a family of semi-active control algorithms termed Active Interaction Control (AIC) used for response control of dynamically excited structures. The AIC approach has been developed as a semi﷓active means of protecting building structures against large earthquakes. The AIC algorithms include the Active Interface Damping (AID), Optimal Connection Strategy (OCS), and newly developed Tuned Interaction Damping (TID) algorithms. All of the AIC algorithms are founded upon ...

  12. Active load control techniques for wind turbines.

    Energy Technology Data Exchange (ETDEWEB)

    van Dam, C.P. (University of California, Davis, CA); Berg, Dale E.; Johnson, Scott J. (University of California, Davis, CA)

    2008-07-01

    This report provides an overview on the current state of wind turbine control and introduces a number of active techniques that could be potentially used for control of wind turbine blades. The focus is on research regarding active flow control (AFC) as it applies to wind turbine performance and loads. The techniques and concepts described here are often described as 'smart structures' or 'smart rotor control'. This field is rapidly growing and there are numerous concepts currently being investigated around the world; some concepts already are focused on the wind energy industry and others are intended for use in other fields, but have the potential for wind turbine control. An AFC system can be broken into three categories: controls and sensors, actuators and devices, and the flow phenomena. This report focuses on the research involved with the actuators and devices and the generated flow phenomena caused by each device.

  13. A state feedback electro-acoustic transducer for active control of acoustic impedance

    Science.gov (United States)

    Samejima, Toshiya

    2003-03-01

    In this paper, a new control system in which the acoustic impedance of an electro-acoustic transducer diaphragm can be actively varied by modifying design parameters is presented and its effectiveness is theoretically investigated. The proposed control system is based on a state-space description of the control system derived from an electrical equivalent circuit of an electro-acoustic transducer to which a differentiating circuit is connected, and is designed using modern control theory. The optimal quadratic regulator is used in the control system design, with its quadratic performance index formulated for producing desired acoustic impedance. Computer simulations indicate that the acoustic impedance of the diaphragm can be significantly varied over a wide frequency range that includes the range below the resonance frequency of the electro-acoustic transducer. A computer model of the proposed control system is used to illustrate its application to semi-active noise control in a duct. It is demonstrated that the proposed control system provides substantial reductions in the noise radiating from the outlet of the duct, both in the stiffness control range and in the mass control range.

  14. Integrated coherent matter wave circuits

    International Nuclear Information System (INIS)

    An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. We report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through their electric polarizability. Moreover, the source of coherent matter waves is a Bose-Einstein condensate (BEC). Finally, we launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry

  15. Active control of vibrations in pedestrian bridges

    OpenAIRE

    Álvaro Cunha; Carlos Moutinho

    1999-01-01

    This paper, apart from making a brief general reference to vibration problems in pedestrian bridges, as well as to the form of modelling of dynamic pedestrian loads, presents the use of a predictive control strategy for the numerical simulation of the dynamic response of actively controlled structures of this type. The consideration of this control strategy permitted the development of a computational model, which was applied to the study of a pedestrian cable-stayed bridge, in order to show ...

  16. Active and passive vibration control of structures

    CERN Document Server

    Spelsberg-Korspeter, Gottfried

    2014-01-01

    Active and Passive Vibration Control of Structures form an issue of very actual interest in many different fields of engineering, for example in the automotive and aerospace industry, in precision engineering (e.g. in large telescopes), and also in civil engineering. The papers in this volume bring together engineers of different background, and it fill gaps between structural mechanics, vibrations and modern control theory.  Also links between the different applications in structural control are shown.

  17. Control of nucleus accumbens activity with neurofeedback

    OpenAIRE

    Greer, Stephanie M.; Trujillo, Andrew J.; Glover, Gary H.; Knutson, Brian

    2014-01-01

    The nucleus accumbens (NAcc) plays critical roles in healthy motivation and learning, as well as in psychiatric disorders (including schizophrenia and attention deficit hyperactivity disorder). Thus, techniques that confer control of NAcc activity might inspire new therapeutic interventions. By providing second-to-second temporal resolution of activity in small subcortical regions, functional magnetic resonance imaging (fMRI) can resolve online changes in NAcc activity, which can then be pres...

  18. Adaptive control of active filter using DSP

    International Nuclear Information System (INIS)

    In order to reduce output-voltage ripple of power supply, an active filter is necessary. In this paper, the active filter with DSP is proposed. The waveform from active filter can be flexibly improved by DSP programming. The output-voltage ripple can be enough reduced by mixing frequency components of the input-voltage ripple. The result of adaptive control using LMS algorism is presented. The improvement by using filtered-X method is discussed. (author)

  19. A Novel LTPS-TFT Pixel Circuit to Compensate the Electronic Degradation for Active-Matrix Organic Light-Emitting Diode Displays

    Directory of Open Access Journals (Sweden)

    Ching-Lin Fan

    2013-01-01

    Full Text Available A novel pixel driving circuit for active-matrix organic light-emitting diode (AMOLED displays with low-temperature polycrystalline-silicon thin-film transistors (LTPS-TFTs is studied. The proposed compensation pixel circuit is driven by voltage programming scheme, which is composed of five TFTs and one capacitor, and has been certified to provide uniform output current by the Automatic Integrated Circuit Modeling Simulation Program with Integrated Circuit Emphasis (AIM-SPICE simulator. The results of simulation show excellent performance, such as the low average error rate of OLED current variation (<0.5% and the low average nonuniformity of OLED current variation (<0.8% while the shift of threshold voltage of the driving poly-Si TFT and the OLED are both in the worst case ( V for TFT and  V for OLED. The proposed pixel circuit shows high immunity to the threshold voltage deviation of both the driving poly-Si TFT and the OLED.

  20. A YAP/TAZ-miR-130/301 molecular circuit exerts systems-level control of fibrosis in a network of human diseases and physiologic conditions

    Science.gov (United States)

    Bertero, Thomas; Cottrill, Katherine A.; Annis, Sofia; Bhat, Balkrishen; Gochuico, Bernadette R.; Osorio, Juan C.; Rosas, Ivan; Haley, Kathleen J.; Corey, Kathleen E.; Chung, Raymond T.; Nelson Chau, B.; Chan, Stephen Y.

    2015-01-01

    The molecular origins of fibrosis affecting multiple tissue beds remain incompletely defined. Previously, we delineated the critical role of the control of extracellular matrix (ECM) stiffening by the mechanosensitive microRNA-130/301 family, as activated by the YAP/TAZ co-transcription factors, in promoting pulmonary hypertension (PH). We hypothesized that similar mechanisms may dictate fibrosis in other tissue beds beyond the pulmonary vasculature. Employing an in silico combination of microRNA target prediction, transcriptomic analysis of 137 human diseases and physiologic states, and advanced gene network modeling, we predicted the microRNA-130/301 family as a master regulator of fibrotic pathways across a cohort of seemingly disparate diseases and conditions. In two such diseases (pulmonary fibrosis and liver fibrosis), inhibition of microRNA-130/301 prevented the induction of ECM modification, YAP/TAZ, and downstream tissue fibrosis. Thus, mechanical forces act through a central feedback circuit between microRNA-130/301 and YAP/TAZ to sustain a common fibrotic phenotype across a network of human physiologic and pathophysiologic states. Such re-conceptualization of interconnections based on shared systems of disease and non-disease gene networks may have broad implications for future convergent diagnostic and therapeutic strategies. PMID:26667495

  1. A Study of Power Systems Stability Enhancement Effects by Excitation Control of Superconducting Generator with High Response Excitation based on Detailed Excitation Circuit Model

    Science.gov (United States)

    Wu, Guohong; Shirato, Hideyuki

    SCG (Superconducting Generator) has a superconducting field winding, which leads to many advantages such as small size, high generation efficiency, low impedance, and so on, and be considered as one of the candidates to meet the needs of high stability and high efficiency in the future power system networks. SCG with high response excitation is especially expected to be able to enhance the transient stability of power system by its SMES (Superconducting Magnetic Energy System) effect. The SMES effect of SCG is recognized that its behaviors are dominated by the structures and controls of its excitation system. For this reason, in order to verify exactly how the SMES effect of SCG influences on the power system stability, the electrical circuits of SCG high response excitation are modeled in detail for conducting digital simulation, and its influence on excitation voltage and active power output of SCG are discussed as well. The simulation results with a typical one machine - infinite bus power system model shows that the SMES effect can be certainly obtained when its exciting power is supplied from SCG terminal bus and may considerably lead to an improvement of power system transient stability.

  2. Wind Turbine Rotors with Active Vibration Control

    DEFF Research Database (Denmark)

    Svendsen, Martin Nymann

    This thesis presents a framework for structural modeling, analysis and active vibration damping of rotating wind turbine blades and rotors. A structural rotor model is developed in terms of finite beam elements in a rotating frame of reference. The element comprises a representation of general...... that these are geometrically well separated. For active vibration control in three-bladed wind turbine rotors the present work presents a resonance-based method for groups of one collective and two whirling modes. The controller is based on the existing resonant format and introduces a dual system...... system. As in the method for non-rotating systems, an explicit procedure for optimal calibration of the controller gains is established. The control system is applied to an 86m wind turbine rotor by means of active strut actuator mechanisms. The prescribed additional damping ratios are reproduced almost...

  3. THE CONTROL AND EVALUATION OF PROMOTIONAL ACTIVITIES

    Directory of Open Access Journals (Sweden)

    Felicia Sabou

    2012-01-01

    Full Text Available The paper focused on importance and benefits of control and evaluation of marketing activities. The control of efficiency review the assessment of the resources for marketing activity, checking also the efficiency of the human resources, advertising, promotion activities and distribution activities. In the analyse of human resources the most important ratio are: the average of costumers visits on a day, the number of custom order received from 100 visits, the number of new customers from a period, the number of lost customers from a period, the marketing human expenditures from all the sales.The strategic control is made to check if the objectives and the company strategy are adapted to the marketing environment.

  4. Integrated Circuit of CMOS DC-DC Buck Converter with Differential Active Inductor

    Directory of Open Access Journals (Sweden)

    Kaoutar Elbakkar

    2011-11-01

    Full Text Available In this paper, we propose a new design of DC-DC buck converter (BC, which the spiral inductor is replaced by a differential gyrator with capacitor load (gyrator-C implemented in 0.18um CMOS process. The gyrator-C transforms the capacitor load (which is the parasitic capacitor of MOSFETS to differential active inductor DAI. The low-Q value of DAI at switching frequency of converter (few hundred kHz is boosted by adding a negative impedance converter (NIC. The transistor parameters of DAI and NIC can be properly chosen to achieve the desirable value of equivalent inductance L (few tens H, and the maximum-Q value at the switching frequency, and thus the efficiency of converter is improved. Experimental results show that the converter supplied with an input voltage of 1V, provides an output voltage of 0.74V and output ripple voltage of 10mV at 155 kHz and Q-value is maximum (#8776;4226 at this frequency.

  5. Adaptive Piezoelectric Absorber for Active Vibration Control

    Directory of Open Access Journals (Sweden)

    Sven Herold

    2016-02-01

    Full Text Available Passive vibration control solutions are often limited to working reliably at one design point. Especially applied to lightweight structures, which tend to have unwanted vibration, active vibration control approaches can outperform passive solutions. To generate dynamic forces in a narrow frequency band, passive single-degree-of-freedom oscillators are frequently used as vibration absorbers and neutralizers. In order to respond to changes in system properties and/or the frequency of excitation forces, in this work, adaptive vibration compensation by a tunable piezoelectric vibration absorber is investigated. A special design containing piezoelectric stack actuators is used to cover a large tuning range for the natural frequency of the adaptive vibration absorber, while also the utilization as an active dynamic inertial mass actuator for active control concepts is possible, which can help to implement a broadband vibration control system. An analytical model is set up to derive general design rules for the system. An absorber prototype is set up and validated experimentally for both use cases of an adaptive vibration absorber and inertial mass actuator. Finally, the adaptive vibration control system is installed and tested with a basic truss structure in the laboratory, using both the possibility to adjust the properties of the absorber and active control.

  6. Active control for performance enhancement of electrically controlled rotor

    Institute of Scientific and Technical Information of China (English)

    Lu Yang; Wang Chao

    2015-01-01

    Electrically controlled rotor (ECR) system has the potential to enhance the rotor perfor-mance by applying higher harmonic flap inputs. In order to explore the feasibility and effectiveness for ECR performance enhancement using closed-loop control method, firstly, an ECR rotor perfor-mance analysis model based on helicopter flight dynamic model is established, which can reflect the performance characteristics of ECR helicopter at high advance ratio. Based on the simulation platform, an active control method named adaptive T-matrix algorithm is adopted to explore the feasibility and effectiveness for ECR performance enhancement. The simulation results verify the effectiveness of this closed-loop control method. For the sample ECR helicopter, about 3%rotor power reduction is obtained with the optimum 2/rev flap inputs at the advance ratio of 0.34. And through analyzing the distributions of attack of angle and drag in rotor disk, the underlying physical essence of ECR power reduction is cleared. Furthermore, the influence of the key control parameters, including convergence factor and weighting matrix, on the effectiveness of closed-loop control for ECR performance enhancement is explored. Some useful results are summarized, which can be used to direct the future active control law design of ECR performance enhancement.

  7. Active control for performance enhancement of electrically controlled rotor

    Directory of Open Access Journals (Sweden)

    Lu Yang

    2015-10-01

    Full Text Available Electrically controlled rotor (ECR system has the potential to enhance the rotor performance by applying higher harmonic flap inputs. In order to explore the feasibility and effectiveness for ECR performance enhancement using closed-loop control method, firstly, an ECR rotor performance analysis model based on helicopter flight dynamic model is established, which can reflect the performance characteristics of ECR helicopter at high advance ratio. Based on the simulation platform, an active control method named adaptive T-matrix algorithm is adopted to explore the feasibility and effectiveness for ECR performance enhancement. The simulation results verify the effectiveness of this closed-loop control method. For the sample ECR helicopter, about 3% rotor power reduction is obtained with the optimum 2/rev flap inputs at the advance ratio of 0.34. And through analyzing the distributions of attack of angle and drag in rotor disk, the underlying physical essence of ECR power reduction is cleared. Furthermore, the influence of the key control parameters, including convergence factor and weighting matrix, on the effectiveness of closed-loop control for ECR performance enhancement is explored. Some useful results are summarized, which can be used to direct the future active control law design of ECR performance enhancement.

  8. Instrumentation and test gear circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Instrumentation and Test Gear Circuits Manual provides diagrams, graphs, tables, and discussions of several types of practical circuits. The practical circuits covered in this book include attenuators, bridges, scope trace doublers, timebases, and digital frequency meters. Chapter 1 discusses the basic instrumentation and test gear principles. Chapter 2 deals with the design of passive attenuators, and Chapter 3 with passive and active filter circuits. The subsequent chapters tackle 'bridge' circuits, analogue and digital metering techniques and circuitry, signal and waveform generation, and p

  9. Active control of ionized boundary layers

    CERN Document Server

    Mendes, R V

    1997-01-01

    The challenging problems, in the field of control of chaos or of transition to chaos, lie in the domain of infinite-dimensional systems. Access to all variables being impossible in this case and the controlling action being limited to a few collective variables, it will not in general be possible to drive the whole system to the desired behaviour. A paradigmatic problem of this type is the control of the transition to turbulence in the boundary layer of fluid motion. By analysing a boundary layer flow for an ionized fluid near an airfoil, one concludes that active control of the transition amounts to the resolution of an generalized integro-differential eigenvalue problem. To cope with the required response times and phase accuracy, electromagnetic control, whenever possible, seems more appropriate than mechanical control by microactuators.

  10. Hexagonal Binary Decision Diagram Quantum Logic Circuits Using Schottky In-Plane and Wrap Gate Control of GaAs and InGaAs Nanowires

    OpenAIRE

    Hasegawa, Hideki; Kasai, Seiya

    2001-01-01

    Previous quantum device research has been done on discrete device levels and lacks a clear vision for high density integration. This paper proposes a new, simple and realistic approach for quantum large scale integrated circuits (QLSIs) where a binary-decision diagram (BDD) logic architecture is implemented by BDD node devices based on quantum wire transistors (QWTrs) and single electron transistors (SETs) realized by the Schottky in-plane gate (IPG) and wrap-gate (WPG) control of III-V hexag...

  11. Active regulation of receptor ratios controls integration of quorum-sensing signals in Vibrio harveyi

    Science.gov (United States)

    Teng, Shu-Wen; Schaffer, Jessica N; Tu, Kimberly C; Mehta, Pankaj; Lu, Wenyun; Ong, N P; Bassler, Bonnie L; Wingreen, Ned S

    2011-01-01

    Quorum sensing is a chemical signaling mechanism used by bacteria to communicate and orchestrate group behaviors. Multiple feedback loops exist in the quorum-sensing circuit of the model bacterium Vibrio harveyi. Using fluorescence microscopy of individual cells, we assayed the activity of the quorum-sensing circuit, with a focus on defining the functions of the feedback loops. We quantitatively investigated the signaling input–output relation both in cells with all feedback loops present as well as in mutants with specific feedback loops disrupted. We found that one of the feedback loops regulates receptor ratios to control the integration of multiple signals. Together, the feedback loops affect the input–output dynamic range of signal transmission and the noise in the output. We conclude that V. harveyi employs multiple feedback loops to simultaneously control quorum-sensing signal integration and to ensure signal transmission fidelity. PMID:21613980

  12. How to control the activated corrosion products source term in PWRs

    International Nuclear Information System (INIS)

    The generalized corrosion of the primary circuit of PWR reactors leads to the deposition of radioactive corrosion products onto the surfaces of the primary loop components which represent important potential causes of harm for the operation and maintenance personnel. The source term is made of all activated chemical species transported by the primary coolant circuit and susceptible to become activated under the neutron flux of the core. The abatement of this source term is a major concern for all nuclear operators and is the object of this conference organized by the French nuclear energy society (SFEN). These proceedings comprise 8 papers and 1 presentation with transparencies. The introductive talk by B. Jeannin (EDF) is illustrated with a series of slides showing the general trend with time of the collective doses received by the personnel of EDF's power plants in controlled areas. (J.S.)

  13. Gq/5-HT2c receptor signals activate a local GABAergic inhibitory feedback circuit to modulate serotonergic firing and anxiety in mice.

    Science.gov (United States)

    Spoida, Katharina; Masseck, Olivia A; Deneris, Evan S; Herlitze, Stefan

    2014-04-29

    Serotonin 2c receptors (5-HT2c-Rs) are drug targets for certain mental disorders, including schizophrenia, depression, and anxiety. 5-HT2c-Rs are expressed throughout the brain, making it difficult to link behavioral changes to circuit specific receptor expression. Various 5-HT-Rs, including 5-HT2c-Rs, are found in the dorsal raphe nucleus (DRN); however, the function of 5-HT2c-Rs and their influence on the serotonergic signals mediating mood disorders remain unclear. To investigate the role of 5-HT2c-Rs in the DRN in mice, we developed a melanopsin-based optogenetic probe for activation of Gq signals in cellular domains, where 5-HT2c-Rs are localized. Our results demonstrate that precise temporal control of Gq signals in 5-HT2c-R domains in GABAergic neurons upstream of 5-HT neurons provides negative feedback regulation of serotonergic firing to modulate anxiety-like behavior in mice. PMID:24733892

  14. Span of Control and Span of Activity

    OpenAIRE

    Oriana Bandiera; Andrea Prat; Raffaella Sadun; Julie Wulf

    2012-01-01

    For both practitioners and researchers, span of control plays an important role in defining and understanding the role of the CEO. In this paper, we combine organizational chart information for a sample of 65 companies with detailed data on how their CEOs allocate their work time, which we define as their span of activity. Span of activity provides a direct measure of the CEO's management style, including the attention devoted to specific subordinates and functions, the time devoted to indivi...

  15. Capital Control, Debt Financing and Innovative Activity

    OpenAIRE

    Czarnitzki, Dirk; Kraft, Kornelius

    2009-01-01

    "The present paper discusses the effects of dispersed versus concentrated capital ownership on investment into innovative activity. While the market for equity capital might exert insufficient control on top managements’ behavior, this weakness may be mitigated by a suitable degree of debt financing. We report the results of an empirical study on the determinants of innovative activity measured by patent applications. Using a large sample of German manufacturing firms, we find that companies ...

  16. Comparison between four piezoelectric energy harvesting circuits

    Institute of Scientific and Technical Information of China (English)

    Jinhao QIU; Hao JIANG; Hongli JI; Kongjun ZHU

    2009-01-01

    This paper investigates and compares the efficiencies of four different interfaces for vibration-based energy harvesting systems. Among those four circuits, two circuits adopt the synchronous switching technique, in which the circuit is switched synchronously with the vibration. In this study, a simple source-less trigger circuit used to control the synchronized switch is proposed and two interface circuits of energy harvesting systems are designed based on the trigger circuit. To validate the effectiveness of the proposed circuits, an experimental system was established and the power harvested by those circuits from a vibration beam was measured. Experimental results show that the two new circuits can increase the harvested power by factors 2.6 and 7, respectively, without consuming extra power in the circuits.

  17. Active Vibration Control of Piezolaminated Smart Beams

    Directory of Open Access Journals (Sweden)

    V. Balamurugan

    2001-04-01

    Full Text Available This paper deals with the active vibration control of beam like structures with distributed piezoelectric sensor and actuator layers bonded on top and bottom surfaces of the beam. A finite element model based on Euler-Bernoulli beam theory has been developed. The contribution of the piezoelectric sensor and actuator layers on the mass and stiffness of the beam is considered. Three types of classical control strategies, namely direct proportional feedback, constant-gain negative velocity feedback and Lyapunov feedback and an optimal control strategy, linear quadratic regulator (LQR scheme are applied to study their control effectiveness. Also, the control performance with different types of loading, such as impulse loading, step loading, harmonic and random loading is studied

  18. A Dynamic Absorber With Active Vibration Control

    Science.gov (United States)

    Huang, S.-J.; Lian, R.-J.

    1994-12-01

    The design and construction of a dynamic absorber incorporating active vibration control is described. The absorber is a two-degrees-of-freedom spring — lumped mass system sliding on a guide pillar, with two internal vibration disturbance sources. Both the main mass and the secondary absorber mass are acted on by DC servo motors, respectively, to suppress the vibration amplitude. The state variable technique is used to model this dynamic system and a decoupling PID control method is used. First, the discrete time state space model is identified by using the commercial software MATLAB. Then the decoupling controller of this multi-input/multi-output system is derived from the identified model. Finally the results of some experiments are presented. The experimental results show that the system is effective in suppressing vibration. Also, the performance of this control strategy for position tracking control is evaluated based on experimental data.

  19. MODELING MERCURY CONTROL WITH POWDERED ACTIVATED CARBON

    Science.gov (United States)

    The paper presents a mathematical model of total mercury removed from the flue gas at coal-fired plants equipped with powdered activated carbon (PAC) injection for Mercury control. The developed algorithms account for mercury removal by both existing equipment and an added PAC in...

  20. Dopamine D1 receptor activation rescues extinction impairments in low-estrogen female rats and induces cortical layer-specific activation changes in prefrontal-amygdala circuits.

    Science.gov (United States)

    Rey, Colin D; Lipps, Jennifer; Shansky, Rebecca M

    2014-04-01

    Post-traumatic stress disorder (PTSD) is twice as common in women as in men; it is a major public health problem whose neurobiological basis is unknown. In preclinical studies using fear conditioning and extinction paradigms, women and female animals with low estrogen levels exhibit impaired extinction retrieval, but the mechanisms that underlie these hormone-based discrepancies have not been identified. There is much evidence that estrogen can modulate dopaminergic transmission, and here we tested the hypothesis that dopamine-estrogen interactions drive extinction processes in females. Intact male and female rats were trained on cued fear conditioning, and received an intraperitoneal injection of a D1 agonist or vehicle before extinction learning. As reported previously, females that underwent extinction during low estrogen estrous phases (estrus/metaestrus/diestrus (EMD)) froze more during extinction retrieval than those that had been in the high-estrogen phase (proestrus; PRO). However, D1 stimulation reversed this relationship, impairing extinction retrieval in PRO and enhancing it in EMD. We also combined retrograde tracing and fluorescent immunohistochemistry to measure c-fos expression in infralimbic (IL) projections to the basolateral area of the amygdala (BLA), a neural pathway known to be critical to extinction retrieval. Again we observed diverging, estrous-dependent effects; SKF treatment induced a positive correlation between freezing and IL-BLA circuit activation in EMD animals, and a negative correlation in PRO animals. These results show for the first time that hormone-dependent extinction deficits can be overcome with non-hormone-based interventions, and suggest a circuit-specific mechanism by which these behavioral effects occur. PMID:24343528

  1. Active vibration control of a full scale aircraft wing using a reconfigurable controller

    Science.gov (United States)

    Prakash, Shashikala; Renjith Kumar, T. G.; Raja, S.; Dwarakanathan, D.; Subramani, H.; Karthikeyan, C.

    2016-01-01

    This work highlights the design of a Reconfigurable Active Vibration Control (AVC) System for aircraft structures using adaptive techniques. The AVC system with a multichannel capability is realized using Filtered-X Least Mean Square algorithm (FxLMS) on Xilinx Virtex-4 Field Programmable Gate Array (FPGA) platform in Very High Speed Integrated Circuits Hardware Description Language, (VHDL). The HDL design is made based on Finite State Machine (FSM) model with Floating point Intellectual Property (IP) cores for arithmetic operations. The use of FPGA facilitates to modify the system parameters even during runtime depending on the changes in user's requirements. The locations of the control actuators are optimized based on dynamic modal strain approach using genetic algorithm (GA). The developed system has been successfully deployed for the AVC testing of the full-scale wing of an all composite two seater transport aircraft. Several closed loop configurations like single channel and multi-channel control have been tested. The experimental results from the studies presented here are very encouraging. They demonstrate the usefulness of the system's reconfigurability for real time applications.

  2. Active control of transmitted sound in buildings

    Science.gov (United States)

    Thompsett, Russell Harvey George

    The problem of noise from neighbours has increased dramatically over the last few years. Many of the noise complaints are due to the high level, low frequency noise from modern stereo equipment, and are often described in terms of the low frequency characteristics of the music; the repetitive, booming, bass beat. The objective of this research was to establish the feasibility of applying active noise control to alleviate this problem. The initial approach was to evaluate the possibility of exploiting the dominance of individual modes in the response of rooms at low frequency to effect global control. However, initial investigations using a modal model of the sound field revealed that this would be difficult due to the contribution of many acoustic modes excited off resonance. This conclusion was supported by measurements of acoustic room responses in typical buildings, illustrating a non-resonant characteristic. Consequently, attention was turned to the feasibility of using local active control systems to create zones of quiet by concentrating control at a specific location near the observers ears, for example in a seat headrest, or near the pillows of a bed. The lack of a reference signal in either approach requires the use of a feedback control strategy. With a typically non-resonant system, the predictability in the disturbance necessary for successful feedback control must be contained in the primary excitation, namely the music. Examples of different music styles were investigated and of those with the potential to be a nuisance surprisingly few were significantly more predictable than a random disturbance. As expected the most encouraging control performance simulations were found for modern dance music, with a strong repetitive beat. A real-time, local controller was demonstrated in the laboratory with such a disturbance signal and the properties of the quiet zone were measured. The subjective response when hearing the controller in operation was found to be

  3. Circuit Quantum Electrodynamics

    CERN Document Server

    Bishop, Lev S

    2010-01-01

    Circuit Quantum Electrodynamics (cQED), the study of the interaction between superconducting circuits behaving as artificial atoms and 1-dimensional transmission-line resonators, has shown much promise for quantum information processing tasks. For the purposes of quantum computing it is usual to approximate the artificial atoms as 2-level qubits, and much effort has been expended on attempts to isolate these qubits from the environment and to invent ever more sophisticated control and measurement schemes. Rather than focussing on these technological aspects of the field, this thesis investigates the opportunities for using these carefully engineered systems for answering questions of fundamental physics.

  4. Active control of multiple resistive wall modes

    International Nuclear Information System (INIS)

    A two-dimensional array of saddle coils at Mc poloidal and Nc toroidal positions is used on the EXTRAP T2R reversed-field pinch (Brunsell P R et al 2001 Plasma Phys. Control. Fusion 43 1457) to study active control of resistive wall modes (RWMs). Spontaneous growth of several RWMs with poloidal mode number m = 1 and different toroidal mode number n is observed experimentally, in agreement with linear MHD modelling. The measured plasma response to a controlled coil field and the plasma response computed using the linear circular cylinder MHD model are in quantitative agreement. Feedback control introduces a linear coupling of modes with toroidal mode numbers n, n' that fulfil the condition |n - n'| = Nc. Pairs of coupled unstable RWMs are present in feedback experiments with an array of Mc x Nc = 4 x 16 coils. Using intelligent shell feedback, the coupled modes are generally not controlled even though the field is suppressed at the active coils. A better suppression of coupled modes may be achieved in the case of rotating modes by using the mode control feedback scheme with individually set complex gains. In feedback with a larger array of Mc x Nc = 4 x 32 coils, the coupling effect largely disappears, and with this array, the main internal RWMs n = -11, -10, +5, +6 are all simultaneously suppressed throughout the discharge (7-8 wall times). With feedback there is a two-fold extension of the pulse length, compared to discharges without feedback

  5. Driving and controlling circuit for full-color OLED based on ARM7%ARM7全彩OLED驱动控制电路设计

    Institute of Scientific and Technical Information of China (English)

    张翔; 蒋泉

    2012-01-01

    介绍了一款全彩无源OLED模块的驱动接口电路及驱动程序的设计.系统采用ARM7系列的LPC2138为控制核心,分别设计了电源电路、下载电路、复位电路和接口电路,并向全彩无源OLED模块提供数据信号和控制信号,从而实现了分辨力为128×128,65×103色的动态全彩图片显示.设计了基于ARM7内核的OLED驱动电路实验系统,可显示红、绿、蓝单色以及全彩图片,为中小尺寸OLED提供了一种低成本、低功耗的单芯片解决方案.%The paper introduces the design of driving circuit, reset circuit, download circuit, interface circuit and driving programs of the full-color passive OLED(organic light emitting device) module in the display system. The system adopts the LPC2138, family of ARM7-core, to control the OLED module. The data and control signals are provided by LPC2138 in order to realize a resolution of 128X 128, 65X 103 dynamic full-color display. Experiment results show that the system can display red, green, blue and full-color pictures, provide a low-cost, low-power and single-chip solution for small sized OLEDs.

  6. 30 CFR 77.904 - Identification of circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Identification of circuit breakers. 77.904... COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.904 Identification of circuit breakers. Circuit breakers shall be labeled to show which circuits they control unless identification...

  7. An Effective Power Management Circuit system for Energy Harvesting Applications

    Directory of Open Access Journals (Sweden)

    Chun-Chang Wu

    2014-05-01

    Full Text Available A high-efficiency power management circuit is realized using TSMC 0.35μm CMOS process to convert energy harvested from the environment for battery storage as a suitable power supply for application circuitry. A high conversion efficiency (74% switching voltage regulator is designed to serve as a digital control circuit with greater tolerance to power noise. For noise-sensitive analog circuits such as amplifiers and the analog-to-digital converters, a linear low dropout (LDO regulator is also designed to provide a cleaner and more stable power supply. In addition, a microcontroller which can effectively control the power switching of each circuit block is also implemented. To prevent power waste, the system blocks normally stay in standby mode with extremely low power consumption. Each block will be turned on only when instructed to activate.

  8. Actively controlled vibration welding system and method

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Wayne W.; Kang, Bongsu; Tan, Chin-An

    2013-04-02

    A vibration welding system includes a controller, welding horn, an active material element, and anvil assembly. The assembly may include an anvil body connected to a back plate and support member. The element, e.g., a piezoelectric stack or shape memory alloy, is positioned with respect to the assembly. The horn vibrates in a desirable first direction to form a weld on a work piece. The element controls any vibrations in a second direction by applying calibrated response to the anvil body in the second direction. A method for controlling undesirable vibrations in the system includes positioning the element with respect to the anvil assembly, connecting the anvil body to the support member through the back plate, vibrating the horn in a desirable first direction, and transmitting an input signal to the element to control vibration in an undesirable second direction.

  9. Control Systems Cyber Security Standards Support Activities

    Energy Technology Data Exchange (ETDEWEB)

    Robert Evans

    2009-01-01

    The Department of Homeland Security’s Control Systems Security Program (CSSP) is working with industry to secure critical infrastructure sectors from cyber intrusions that could compromise control systems. This document describes CSSP’s current activities with industry organizations in developing cyber security standards for control systems. In addition, it summarizes the standards work being conducted by organizations within the sector and provides a brief listing of sector meetings and conferences that might be of interest for each sector. Control systems cyber security standards are part of a rapidly changing environment. The participation of CSSP in the development effort for these standards has provided consistency in the technical content of the standards while ensuring that information developed by CSSP is included.

  10. BWR startup and shutdown activity transport control

    International Nuclear Information System (INIS)

    This paper summarizes BWR industry experience on good practices for controlling the transport of corrosion product activity during shutdowns, particularly refueling outages, and for startup chemistry control to minimize IGSCC (intergranular stress corrosion cracking). For shutdown, overall goals are to minimize adverse impacts of crud bursts and the time required to remove activated corrosion products from the reactor coolant during the shutdown process prior to refueling, and to assist plants in predicting and controlling radiation exposure during outages. For startup, the overall goals are to highlight conditions during early heatup and startup when sources of reactor coolant oxidants are high, when there is a greater likelihood for chemical excursions associated with refueling outage work activities, and when hydrogen injection is not available to mitigate IGSCC due to system design limitations. BWR water chemistry has changed significantly in recent years with the adoption of hydrogen water chemistry, zinc addition and noble metal chemical applications. These processes have, in some instances, resulted in significant activity increases during shutdown evolutions, which together with reduced time for cleanup because of shorter outages, has consequently increased outage radiation exposure. A review several recent outages shows that adverse effects from these conditions can be minimized, leading to the set of good practice recommendations for shutdown chemistry control. Most plants lose the majority of their hydrogen availability hours during early startup because feedwater hydrogen injection systems were not originally designed to inject hydrogen below 20% power. Hydrogen availability has improved through modifications to inject hydrogen at lower power levels, some near 5%. However, data indicate that IGSCC is accelerated during early startup, when dissolved oxygen and hydrogen peroxide levels are high and reactor coolant temperatures are in the 300 to 400 oF (

  11. EDA circuit simulation

    International Nuclear Information System (INIS)

    EDA technique is used for circuit simulation. The circuit simulation and the analysis are made for a gate circuit one-shot multivibrator. The result shows: EDA circuit simulation is very useful technique

  12. Active Control of Long Bridges Using Flaps

    DEFF Research Database (Denmark)

    Hansen, H. I.; Thoft-Christensen, Palle

    The main problem in designing ultra-long span suspension bridges is flutter. A solution to this problem might be to introduce an active flap control system to increase the flutter wind velocity. The investigated flap control system consists of flaps integrated in the bridge girder so each flap is...... different flap configurations for a bridge section model by using aerodynamic derivatives for a flat plate. The example shows that different flap configurations can either increase or decrease the flutter wind velocity. for optimal flap configurations flutter will not occur....

  13. Electronic design with integrated circuits

    Science.gov (United States)

    Comer, D. J.

    The book is concerned with the application of integrated circuits and presents the material actually needed by the system designer to do an effective job. The operational amplifier (op amp) is discussed, taking into account the electronic amplifier, the basic op amp, the practical op amp, analog applications, and digital applications. Digital components are considered along with combinational logic, digital subsystems, the microprocessor, special circuits, communications, and integrated circuit building blocks. Attention is given to logic gates, logic families, multivibrators, the digital computer, digital methods, communicating with a computer, computer organization, register and timing circuits for data transfer, arithmetic circuits, memories, the microprocessor chip, the control unit, communicating with the microprocessor, examples of microprocessor architecture, programming a microprocessor, the voltage-controlled oscillator, the phase-locked loop, analog-to-digital conversion, amplitude modulation, frequency modulation, pulse and digital transmission, the semiconductor diode, the bipolar transistor, and the field-effect transistor.

  14. Laminar circuit organization and response modulation in mouse visual cortex

    Directory of Open Access Journals (Sweden)

    Victor Quintanar-Zilinskas

    2012-10-01

    Full Text Available The mouse has become an increasingly important animal model for visual system studies, but few studies have investigated local functional circuit organization of mouse visual cortex. Here we used our newly developed mapping technique combining laser scanning photostimulation (LSPS with fast voltage-sensitive dye (VSD imaging to examine the spatial organization and temporal dynamics of laminar circuit responses in living slice preparations of mouse primary visual cortex (V1. During experiments, LSPS using caged glutamate provided spatially restricted neuronal activation in a specific cortical layer, and evoked responses from the stimulated layer to its functionally connected regions were detected by VSD imaging. In this study, we first provided a detailed analysis of spatiotemporal activation patterns at specific V1 laminar locations and measured local circuit connectivity. Then we examined the role of cortical inhibition in the propagation of evoked cortical responses by comparing circuit activity patterns in control and in the presence of GABAa receptor antagonists. We found that GABAergic inhibition was critical in restricting layer-specific excitatory activity spread and maintaining topographical projections. In addition, we investigated how AMPA and NMDA receptors influenced cortical responses and found that blocking AMPA receptors abolished interlaminar functional projections, and the NMDA receptor activity was important in controlling visual cortical circuit excitability and modulating activity propagation. The NMDA receptor antagonist reduced neuronal population activity in time-dependent and laminar-specific manners. Finally, we used the quantitative information derived from the mapping experiments and presented computational modeling analysis of V1 circuit organization. Taken together, the present study has provided important new information about mouse V1 circuit organization and response modulation.

  15. An adaptive synchronization strategy based on active control for demodulating message hidden in chaotic signals

    International Nuclear Information System (INIS)

    In the field of secure communication, it is very important to demodulate the message hidden in chaotic signals. In this paper, an adaptive synchronization strategy based on active control is proposed, which is used to design an active controller and an appropriate adaptive demodulator at the receiver to recover the transmitted message hidden in chaotic signals of a drive system. Based on Lyapunov stability theory, it is shown that the transmitted message can be theoretically recovered by using the proposed strategy. Numerical simulations based on the Chua's circuit are also presented to verify the effectiveness of the proposed strategy. In addition, it is shown via simulations that, by increasing the gain of the active controller the message error caused by the external noise and the discontinuous property of the message can be reduced

  16. Jacket Substructure Fatigue Mitigation through Active Control

    DEFF Research Database (Denmark)

    Hanis, Tomas; Natarajan, Anand

    As offshore wind farms are being installed farther and in deeper waters offshore, new, and more sophisticated marine substructures such as jackets need to be used. Herein, a 10MW wind turbine mounted on a jacket sub structure at a mean water depth of 50 meters is investigated with regards to the...... fatigue design loads on the braces of the jacket. Since large wind turbines of 10MW rating have low rotor speeds (p), the modal frequencies of the sub structures approach 3p at low wind speeds, which leads to a modal coupling and resonance. Therefore an active control system is developed which provides...... sufficient structural damping and consequently a fatigue reduction at the substructure. The resulting reduction in fatigue design loads on the jacket structure based on the active control system is presented....

  17. Evolution of transcriptional regulatory circuits in bacteria

    OpenAIRE

    Perez, J. Christian; Groisman, Eduardo A.

    2009-01-01

    Related organisms typically respond to a given cue by altering the level or activity of orthologous transcription factors, which, paradoxically, often regulate expression of distinct gene sets. Although promoter rewiring of shared genes is primarily responsible for regulatory differences among related eukaryotic species, in bacteria, species-specific genes are often controlled by ancestral transcription factors and regulatory circuit evolution has been further shaped by horizontal gene transf...

  18. Active Noise Control in Forest Machines

    OpenAIRE

    Forsgren, Fredrik

    2011-01-01

    Achieving a low noise level is of great interest to the forest machine industry. Traditionally this is obtained by using passive noise reduction, i.e. by using materials for sound isolation and sound absorption. Especially designs to attenuate low frequency noise tend to be bulky and impractical from an installation point of view. An alternative solution to the problem is to use active noise control (ANC). The basic principle of ANC is to generate an anti-noise signal designed to destructivel...

  19. Analog and VLSI circuits

    CERN Document Server

    Chen, Wai-Kai

    2009-01-01

    Featuring hundreds of illustrations and references, this book provides the information on analog and VLSI circuits. It focuses on analog integrated circuits, presenting the knowledge on monolithic device models, analog circuit cells, high performance analog circuits, RF communication circuits, and PLL circuits.

  20. Investigation on Controlled Power-on Circuit of Rectifier%整流器可控上电电路的研究

    Institute of Scientific and Technical Information of China (English)

    曹中圣; 王虎; 杨喜军

    2011-01-01

    As the storage charge does not exist in the cold state electrolytic capacitor, charging on the capaeitor without any measure will cause the high amplitude surge current, which may result in failure on charging or even damage to the circuit. This paper describes a DC link controlled voltage power-on circuit, which can charge the capacitor with arbitrary voltage waveform for three-phase rectifier and high power factor for single-phase rectifier. The circuit topology is presented, and the working principle is analyzed by theory and simulation. The analysis results show that the proposed power-on circuit is feasible.%由于冷态电解电容储存电荷为零,不采取措施的情况下上电,将引起整流电路较高幅值的浪涌电流,轻者引起上电失败,重者危害电路安全.该文提出一种直流回路电压可控的上电电路,对十三相整流电路可以实现直流回路电压任意波形上电,对于单相整流电路可以实现高功率因数上电.给出了电路拓扑,对其工作原理进行了理沦分析和仿真验证,所得结果表明,所提出的上电电路具有可行性.

  1. Active Thermal Control System Development for Exploration

    Science.gov (United States)

    Westheimer, David

    2007-01-01

    All space vehicles or habitats require thermal management to maintain a safe and operational environment for both crew and hardware. Active Thermal Control Systems (ATCS) perform the functions of acquiring heat from both crew and hardware within a vehicle, transporting that heat throughout the vehicle, and finally rejecting that energy into space. Almost all of the energy used in a space vehicle eventually turns into heat, which must be rejected in order to maintain an energy balance and temperature control of the vehicle. For crewed vehicles, Active Thermal Control Systems are pumped fluid loops that are made up of components designed to perform these functions. NASA has been actively developing technologies that will enable future missions or will provide significant improvements over the state of the art technologies. These technologies have are targeted for application on the Crew Exploration Vehicle (CEV), or Orion, and a Lunar Surface Access Module (LSAM). The technologies that have been selected and are currently under development include: fluids that enable single loop ATCS architectures, a gravity insensitive vapor compression cycle heat pump, a sublimator with reduced sensitivity to feedwater contamination, an evaporative heat sink that can operate in multiple ambient pressure environments, a compact spray evaporator, and lightweight radiators that take advantage of carbon composites and advanced optical coatings.

  2. Active control of electric potential of spacecraft

    Science.gov (United States)

    Goldstein, R.

    1977-01-01

    Techniques are discussed for controlling the potential of a spacecraft by means of devices which release appropriate charged particles from the spacecraft to the environment. Attention is given to electron emitters, ion emitters, a basic electron emitter arrangement, techniques for sensing electric field or potential, and flight experiments on active potential control. It is recommended to avoid differential charging on spacecraft surfaces because it can severely affect the efficacy of emitters. Discharging the frame of a spacecraft with dielectric surfaces involves the risk of stressing the dielectric material excessively. The spacecraft should, therefore, be provided with grounded conductive surfaces. It is pointed out that particles released by control systems can return to the spacecraft.

  3. Active Control of Shear Thickening in Suspensions

    CERN Document Server

    Lin, Neil Y C; Cates, Michael E; Sun, Jin; Cohen, Itai

    2016-01-01

    Shear thickening, an increase of viscosity with shear rate, is a ubiquitous phenomena in suspended materials that has implications for broad technological applications. Controlling this thickening behavior remains a major challenge and has led to empirical strategies ranging from altering the particle surfaces and shape to modifying the solvent properties. However, none of these methods allow for active control of flow properties during shear itself. Here, we demonstrate that by strategic imposition of a high-frequency and low-amplitude shear perturbation orthogonal to the primary shearing flow, we can largely eradicate shear thickening. The orthogonal shear effectively becomes a regulator for controlling thickening in the suspension, allowing the viscosity to be reduced by up to two decades on demand. In a separate setup, we show that such effects can be induced by simply agitating the sample transversely to the primary shear direction. Overall, the ability of in situ manipulation of shear thickening paves a...

  4. Circuits courts

    OpenAIRE

    Dubuisson-Quellier, Sophie

    2015-01-01

    Si la notion de circuit court est aujourd’hui largement reprise par les médias comme un phénomène assez typique de la fin du 20ème siècle, il convient de considérer que la vente directe est aussi ancienne que l’agriculture elle-même. Au tournant des années 2000, elle est surtout devenu un moyen, pour ceux qui la promeuvent de souligner que les distances tant géographiques qu’organisationnelles entre ceux qui produisent et ceux qui consomment sont devenus trop longues et doivent être raccourci...

  5. FPGA Based Adaptive Neuro Fuzzy Inference Controller for Full Vehicle Nonlinear Active Suspension Systems

    Directory of Open Access Journals (Sweden)

    Ammar A. Aldair

    2010-10-01

    Full Text Available A Field Programmable Gate Array (FPGA is proposed to build an Adaptive Neuro Fuzzy Inference System (ANFIS for controlling a full vehicle nonlinear active suspension system. A Very High speed integrated circuit Hardware Description Language (VHDL has been used to implement the proposed controller. An optimal Fraction Order PIλ D µ (FOPID controller is designed for a full vehicle nonlinear active suspension system. Evolutionary Algorithm (EA has been applied to modify the five parameters of the FOPID controller (i.e. proportional constant Kp, integral constant Ki , derivative constant Kd, integral order λ and derivative order µ. The data obtained from the FOPID controller are used as a reference to design the ANFIS model as a controller for the controlled system. A hybrid approach is introduced to train the ANFIS. A Matlab Program has been used to design and simulate the proposed controller. The ANFIS control parameters obtained from the Matlab program are used to write the VHDL codes. Hardware implementation of the FPGA is dependent on the configuration file obtained from the VHDL program. The experimental results have proved the efficiency and robustness of the hardware implementation for the proposed controller. It provides a novel technique to be used to design NF controller for full vehicle nonlinear active suspension systems with hydraulic actuators.

  6. The Circuit Simulation of Half-Bridge Converter with PWM Control Method%PWM半桥变换器电路仿真

    Institute of Scientific and Technical Information of China (English)

    左是

    2011-01-01

    随着电力电子技术的迅速发展,PWM型DC-DC变换器的应用日益广泛。如今,高性能、高效率、小型化和轻量化越来越成为各类DC-DC变换器追求的目标。文中优选电路结构简单、容易控制的半桥电路作为直直变换拓扑,在剖析了脉宽调制对称半桥变换器工作原理及特性后,设计出270 V直流输入、360 V直流输出、输出功率为500 W变换器的相关参数。切实了解SG1525芯片脉冲产生原理后,设计出控制电路参数,从而搭建出完整的闭环系统。详尽分析了所得出仿真结果,并以此验证了理论分析和工程设计的正确性。%With the rapid development of power electronics technology,the applications of PWM DC-DC converter is widely used,and now,high performance,high efficiency,miniaturization and lightweight model has tended to be the goal of PWM DC-DC converter.In this paper,the common DC-DC converter topology is analysed,and in view of its simple circuit structure,easy control method half-bridge circuit may suit for small and medium-capacity as a DC-DC conversion topology.In the analysis of PWM converter operating principle and circuit characteristics,this paper achieves the design parameters of 270 V DC input,360 V DC output,and 500 W output power converter.After well understanding the producing pulse principle of SG1525 chip,it realizes the design parameters of control circuit,thus build a complete closed-loop system.After obtained a detailed analysis of the experimental results,this paper verifies the theoretical analysis and circuit simulation is correct.

  7. Testing of five methods for the control of zebra mussels in cooling circuits of power plants located on the Moselle river

    International Nuclear Information System (INIS)

    Bioassays have been conducted on site at the Cattenom nuclear power plant located on the Moselle River (in northeast France) to control mussels in auxiliary plant circuits. During the course of a two-year program, five methods were tested: - thermal treatment (33 deg to 40 deg C), - high dosage chlorination (> 50 ppm), - low dosage chlorine dioxide, - potassium salt (KCI > 100 ppm), - one organic compound (Mexel 432). This note presents a comparison of the treatments shown to be most effective, on the basis of technical feasibility, cost and environmental acceptability. (author). 8 figs., 10 refs., 3 tabs

  8. A Flexible Power Control Method of VSC-HVDC Link for the Enhancement of Effective Short-Circuit Ratio in a Hybrid Multi-Infeed HVDC System

    DEFF Research Database (Denmark)

    Liu, Yan; Chen, Zhe

    2013-01-01

    . To evaluate the contribution of the VSC-HVDC link on the voltage stability of HMIDC system, this paper proposes an effective short circuit ratio (ESCR) calculation method. Through the calculation, the voltage support capability of the VSC-HVDC link can be quantitatively represented by the ESCR....... Furthermore, based on the calculation results, a flexible power control strategy for the VSC-HVDC link is developed to provide maximum reactive power support under grid faults. The theoretical analysis of the HMIDC system is based on the Danish transmission grid, evaluated through PSCAD simulations under...

  9. 47 CFR 32.2232 - Circuit equipment.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Circuit equipment. 32.2232 Section 32.2232... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2232 Circuit equipment... which is used for the amplification, modulation, regeneration, circuit patching, balancing or control...

  10. Short- circuit tests of circuit breakers

    OpenAIRE

    Chorovský, P.

    2015-01-01

    This paper deals with short-circuit tests of low voltage electrical devices. In the first part of this paper, there are described basic types of short- circuit tests and their principles. Direct and indirect (synthetic) tests with more details are described in the second part. Each test and principles are explained separately. Oscilogram is obtained from short-circuit tests of circuit breakers at laboratory. The aim of this research work is to propose a test circuit for performing indirect test.

  11. A study on the short-circuit test by fault angle control and the recovery characteristics of the fault current limiter using coated conductor

    International Nuclear Information System (INIS)

    Superconducting fault current limiters (SFCLs) have been developed in many countries, and they are expected to be used in the recent electric power systems, because of their great efficiency for operating these power system stably. It is necessary for resistive FCLs to generate resistance immediately and to have a fast recovery characteristic after the fault clearance, because of re-closing operation. Short-circuit tests are performed to obtained current limiting operational and recovery characteristics of the FCL by a fault controller using a power switching device. The power switching device consists of anti-parallel connected thyristors. The fault occurs at the desired angle by controlling the firing angle of thyristors. Resistive SFCLs have different current limiting characteristics with respect to the fault angle in the first swing during the fault. This study deals with the short-circuit characteristic of FCL coils using two different YBCO coated conductors (CCs), 344 and 344s, by controlling the fault angle and experimental studies on the recovery characteristic by a small current flowing through the SFCL after the fault clearance. Tests are performed at various voltages applied to the SFCL in a saturated liquid nitrogen cooling system

  12. SEMI-ACTIVE CONTROL OF VEHICLE SUSPENSION WITH MAGNETO-RHEOLOGICAL DAMPERS:PART III——EXPERIMENTAL VALIDATION

    Institute of Scientific and Technical Information of China (English)

    WANG Enrong; YING Liang; WANG Wanjun; RAKHEJA Subhash; SU Chunyi

    2008-01-01

    A hardware-in-the-loop (HIL) test and simulation platform is developed in the laboratory, so as to validate the performance characteristics of the proposed skyhook-based asymmetric semi-active controller in Part I, and examine the validity of the proposed MR-damper model in a system surrounding. A real-time monitor is designed to assess and monitor the responses of the quarter-vehicle model in the HIL platform, and to select the excitation, controller synthesis, and the output displays. A drive current circuit hardware employing PID feedback technique is developed to compensate for the time delays from the servo-controller and drive current circuit, in which a small resistance is integrated in the current amplifier circuit to provide the feedback signal. The experiments were performed to measure the responses of the quarter-vehicle MR-suspension models with fixed current and the proposed semi-active MR-damping variations, under harmonic, rounded pulse and random road excitations. The measured data were compared with the corresponding model results to examine the model and controller validity, and revealed generally good agreements in the model and tested results and very little sensitivity of the tested responses to variations in the sprung mass. The HIL test results validate the effectiveness of the proposed skyhook-based semi-active asymmetric controller and its high robustness against the vehicle load variations in view of the intelligent vehicle suspension design.

  13. Trip electrical circuit of the gyrotion

    International Nuclear Information System (INIS)

    The electron cyclotron resonance heating system of INPE/LAP is shown and the trip electrical circuit of the gyrotron is described, together with its fundamental aspects. The trip electrical circuit consists basically of a series regulator circuit which regulates the output voltage level and controls the pulse width time. Besides that, a protection circuit for both tubes, regulator and gyrotron, against faults in the system. (author)

  14. An Equivalent Circuit for Landau Damping

    DEFF Research Database (Denmark)

    Pécseli, Hans

    1976-01-01

    An equivalent circuit simulating the effect of Landau damping in a stable plasma‐loaded parallel‐plate capacitor is presented. The circuit contains a double infinity of LC components. The transition from stable to unstable plasmas is simulated by the introduction of active elements into the circuit....

  15. Coordinated Voltage Control of Active Distribution Network

    Directory of Open Access Journals (Sweden)

    Xie Jiang

    2016-01-01

    Full Text Available This paper presents a centralized coordinated voltage control method for active distribution network to solve off-limit problem of voltage after incorporation of distributed generation (DG. The proposed method consists of two parts, it coordinated primal-dual interior point method-based voltage regulation schemes of DG reactive powers and capacitors with centralized on-load tap changer (OLTC controlling method which utilizes system’s maximum and minimum voltages, to improve the qualified rate of voltage and reduce the operation numbers of OLTC. The proposed coordination has considered the cost of capacitors. The method is tested using a radial edited IEEE-33 nodes distribution network which is modelled using MATLAB.

  16. Controller modification applied for active fault detection

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob; Poulsen, Niels Kjølstad

    2014-01-01

    This paper is focusing on active fault detection (AFD) for parametric faults in closed-loop systems. This auxiliary input applied for the fault detection will also disturb the external output and consequently reduce the performance of the controller. Therefore, only small auxiliary inputs are used...... modify the feedback controller with a minor effect on the external output in the fault free case. Further, in the faulty case, the signature of the auxiliary input can be optimized. This is obtained by using a band-pass filter for the YJBK parameter that is only effective in a small frequency range where...... the frequency for the auxiliary input is selected. This gives that it is possible to apply an auxiliary input with a reduced amplitude. An example is included to show the results....

  17. Lactate Regulates Metabolic and Pro-inflammatory Circuits in Control of T Cell Migration and Effector Functions.

    Directory of Open Access Journals (Sweden)

    Robert Haas

    2015-07-01

    Full Text Available Lactate has long been considered a "waste" by-product of cell metabolism, and it accumulates at sites of inflammation. Recent findings have identified lactate as an active metabolite in cell signalling, although its effects on immune cells during inflammation are largely unexplored. Here we ask whether lactate is responsible for T cells remaining entrapped in inflammatory sites, where they perpetuate the chronic inflammatory process. We show that lactate accumulates in the synovia of rheumatoid arthritis patients. Extracellular sodium lactate and lactic acid inhibit the motility of CD4+ and CD8+ T cells, respectively. This selective control of T cell motility is mediated via subtype-specific transporters (Slc5a12 and Slc16a1 that we find selectively expressed by CD4+ and CD8+ subsets, respectively. We further show both in vitro and in vivo that the sodium lactate-mediated inhibition of CD4+ T cell motility is due to an interference with glycolysis activated upon engagement of the chemokine receptor CXCR3 with the chemokine CXCL10. In contrast, we find the lactic acid effect on CD8+ T cell motility to be independent of glycolysis control. In CD4+ T helper cells, sodium lactate also induces a switch towards the Th17 subset that produces large amounts of the proinflammatory cytokine IL-17, whereas in CD8+ T cells, lactic acid causes the loss of their cytolytic function. We further show that the expression of lactate transporters correlates with the clinical T cell score in the synovia of rheumatoid arthritis patients. Finally, pharmacological or antibody-mediated blockade of subtype-specific lactate transporters on T cells results in their release from the inflammatory site in an in vivo model of peritonitis. By establishing a novel role of lactate in control of proinflammatory T cell motility and effector functions, our findings provide a potential molecular mechanism for T cell entrapment and functional changes in inflammatory sites that drive

  18. Development, integration and testing of automated triggering circuit for hybrid DC circuit breaker

    International Nuclear Information System (INIS)

    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. (author)

  19. 含磁控和荷控两种忆阻器的混沌电路设计与仿真%Design and simulation of chaotic circuit for flux-controlled memristor and charge-controlled memristor

    Institute of Scientific and Technical Information of China (English)

    洪庆辉; 曾以成; 李志军

    2013-01-01

    利用惠普实验室荷控和磁控两种忆阻器模型设计了一个五阶混沌电路。数值仿真结果表明该电路在参数变化情况下能产生Hopf分岔和反倍周期分岔两种分岔行为,并能产生双涡卷、单涡卷、周期态等不同相轨道。为了验证电路的混沌行为,利用基本元器件设计了惠普实验室荷控和磁控忆阻器模拟器,并将其应用到对所设计电路中进行Pspice仿真,电路仿真结果验证了理论分析的正确性。%In this work,we design a fifth-order chaotic circuit with HP memristors, which consists of a flux-controlled memristor and a charge-controlled memristor. By changing the control parameters, the circuit evolves into different orbits, such as periodic orbits, double-scroll, of single-scroll. In order to ensure the occurrence of chaotic behaviors in the circuit, simulators of the charge-controlled memristor and the flux-controlled memristor are designed with conventional electronic devices, and Pspice simulation is conducted on the resulting circuit. Pspice simulation results verify the correctness of the theorectical analysis.

  20. Demultiplexer circuit for neural stimulation

    Science.gov (United States)

    Wessendorf, Kurt O; Okandan, Murat; Pearson, Sean

    2012-10-09

    A demultiplexer circuit is disclosed which can be used with a conventional neural stimulator to extend the number of electrodes which can be activated. The demultiplexer circuit, which is formed on a semiconductor substrate containing a power supply that provides all the dc electrical power for operation of the circuit, includes digital latches that receive and store addressing information from the neural stimulator one bit at a time. This addressing information is used to program one or more 1:2.sup.N demultiplexers in the demultiplexer circuit which then route neural stimulation signals from the neural stimulator to an electrode array which is connected to the outputs of the 1:2.sup.N demultiplexer. The demultiplexer circuit allows the number of individual electrodes in the electrode array to be increased by a factor of 2.sup.N with N generally being in a range of 2-4.

  1. Real Time Vibration Control of Active Suspension System with Active Force Control using Iterative Learning Algorithm

    Directory of Open Access Journals (Sweden)

    Kalaivani

    2013-09-01

    Full Text Available This paper presents concurrent vibration control of a laboratory scaled vibration isolator platform with Active Force Control (AFC using Iterative Learning Algorithm (ILA. The work investigates the performance of the traditional Proportional Integral Derivative Controller (PIDC with and without AFC using ILA for vibration suppression. The physical single degree of freedom quarter car has been interfaced with a personal computer using a National Instruments data acquisition card NI USB 6008. The controllers are designed and simulated using LabVIEW simulation software. The results infer that the PIDC with AFC using ILA works superior than the PIDC.

  2. Improved simulation of stabilizer circuits

    International Nuclear Information System (INIS)

    The Gottesman-Knill theorem says that a stabilizer circuit - that is, a quantum circuit consisting solely of controlled-NOT (CNOT), Hadamard, and phase gates - can be simulated efficiently on a classical computer. This paper improves that theorem in several directions. First, by removing the need for Gaussian elimination, we make the simulation algorithm much faster at the cost of a factor of 2 increase in the number of bits needed to represent a state. We have implemented the improved algorithm in a freely available program called CHP (CNOT-Hadamard-phase), which can handle thousands of qubits easily. Second, we show that the problem of simulating stabilizer circuits is complete for the classical complexity class +L, which means that stabilizer circuits are probably not even universal for classical computation. Third, we give efficient algorithms for computing the inner product between two stabilizer states, putting any n-qubit stabilizer circuit into a 'canonical form' that requires at most O(n2/log n) gates, and other useful tasks. Fourth, we extend our simulation algorithm to circuits acting on mixed states, circuits containing a limited number of nonstabilizer gates, and circuits acting on general tensor-product initial states but containing only a limited number of measurements

  3. Real-Time Control of Active and Reactive Power for Doubly Fed Induction Generator (DFIG)-Based Wind Energy Conversion System

    OpenAIRE

    Aman Abdulla Tanvir; Adel Merabet; Rachid Beguenane

    2015-01-01

    This paper presents the modeling, rapid control prototyping, and hardware-in-the-loop testing for real-time simulation and control of a grid-connected doubly fed induction generator (DFIG) in a laboratory-size wind turbine emulator for wind energy conversation systems. The generator is modeled using the direct-quadrature rotating reference frame circuit along with the aligned stator flux, and the field-oriented control approach is applied for independent control of the active and reactive pow...

  4. Alterations in the motor neuron-Renshaw cell circuit in the Sod1G93A mouse model

    OpenAIRE

    Wootz, Hanna; FitzSimons-Kantamneni, Eileen; Larhammar, Martin; Rotterman, Travis M.; Enjin, Anders; Patra, Kalicharan; Andre, Elodie; van Zundert, Brigitte; Kullander, Klas; Alvarez, Francisco J.

    2013-01-01

    Motor neurons become hyperexcitable during progression of amyotrophic lateral sclerosis (ALS). This abnormal firing behavior has been explained by changes in their membrane properties, but more recently it has been suggested that changes in premotor circuits may also contribute to this abnormal activity. The specific circuits that may be altered during development of ALS have not been investigated. Here we examined the Renshaw cell recurrent circuit that exerts inhibitory feedback control on ...

  5. Biocompatibility and pathways of initial complement pathway activation with Phisio- and PMEA-coated cardiopulmonary bypass circuits during open-heart surgery.

    Science.gov (United States)

    Thiara, A S; Mollnes, T E; Videm, V; Andersen, V Y; Svennevig, K; Kolset, S O; Fiane, A E

    2011-03-01

    A randomized open-heart surgery study comprising 30 patients was undertaken to compare the biocompatibility of Phisio-(phosphorylcholine) and PMEA-(poly-2-methoxyethyl acrylate) coated cardiopulmonary bypass (CPB) circuits and to assess the initial complement pathway activation during open-heart surgery. Blood samples were obtained at five time points, from the start of surgery to 24 hours postoperatively. The following analyses were performed: haemoglobin, lactate dehydrogenase, leukocyte and platelet counts, myeloperoxidase and neutrophil-activating peptide-2, thrombin-anti-thrombin complexes, syndecan-1 and the complement activation products C1rs-C1-inhibitor complexes, C4bc, C3bc, C3bBbP and the terminal complement complex (TCC). No significant inter-group difference was found in any parameters, except for the concentration of TCC which was moderately lower in the PMEA group at termination of CPB. Complement activation during open-heart surgery was mainly mediated through the alternative pathway. In conclusion, PMEA- and Phisio-coated circuits displayed similar biocompatibility with respect to inflammatory and haemostatic responses during and after open-heart surgery. PMID:21177724

  6. Techniques for control of long-term reliability of complex integrated circuits. I - Reliability assurance by test vehicle qualification.

    Science.gov (United States)

    Van Vonno, N. W.

    1972-01-01

    Development of an alternate approach to the conventional methods of reliability assurance for large-scale integrated circuits. The product treated is a large-scale T squared L array designed for space applications. The concept used is that of qualification of product by evaluation of the basic processing used in fabricating the product, providing an insight into its potential reliability. Test vehicles are described which enable evaluation of device characteristics, surface condition, and various parameters of the two-level metallization system used. Evaluation of these test vehicles is performed on a lot qualification basis, with the lot consisting of one wafer. Assembled test vehicles are evaluated by high temperature stress at 300 C for short time durations. Stressing at these temperatures provides a rapid method of evaluation and permits a go/no go decision to be made on the wafer lot in a timely fashion.

  7. Acute Effects of Three Different Circuit Weight Training Protocols on Blood Lactate, Heart Rate, and Rating of Perceived Exertion in Recreationally Active Women

    OpenAIRE

    Skidmore, Brook L.; Jones, Margaret T; Mark Blegen; Matthews, Tracey D.

    2012-01-01

    Interval and circuit weight training are popular training methods for maximizing time-efficiency, and are purported to deliver greater physiological benefits faster than traditional training methods. Adding interval training into a circuit weight-training workout may further enhance the benefits of circuit weight training by placing increased demands upon the cardiovascular system. Our purpose was to compare acute effects of three circuit weight training protocols 1) traditional circuit weigh...

  8. New Digital Control System for the JET Alfv'en Eigenmode Active Spectroscopy Diagnostic

    Science.gov (United States)

    Woskov, P. P.; Stillerman, J.; Porkolab, M.; Fasoli, A.; Testa, D.; Galvao, R.; Pires Dos Resis, A.; Pires de Sa, W.; Ruchko, L.; Blanchard, P.; Figueiredo, J.; Dorling, S.; Farthing, J.; Graham, M.; Dowson, S.; Yu, L.; Concezzi, S.

    2012-10-01

    The state-of-the-art JET Alfv'en active spectroscopy diagnostic with eight internal inductive antennas is being upgraded from a single 5 kW tube amplifier to eight parallel, 10 -- 1000 kHz, 4 kW solid state class D power switching amplifiers. A new digital control system has been designed with arbitrary constant phase controlled frequency sweeps for traveling mode studies, amplifier gain control through a feedback loop referenced to programmed antenna current profiles, and integration with CODAS for synchronization, triggering, gating, and fault tripping. A combination of National Instruments Real Time LabView software and FPGA circuits is used to achieve the multiple control requirements with better than 1 ms response. System specifications and digital-analog design trade offs for sweep rates, response times, frequency resolution, and voltage levels will be presented.

  9. Variational integrators for electric circuits

    International Nuclear Information System (INIS)

    In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electric circuit, one is faced with three special situations: 1. The system involves external (control) forcing through external (controlled) voltage sources and resistors. 2. The system is constrained via the Kirchhoff current (KCL) and voltage laws (KVL). 3. The Lagrangian is degenerate. Based on a geometric setting, an appropriate variational formulation is presented to model the circuit from which the equations of motion are derived. A time-discrete variational formulation provides an iteration scheme for the simulation of the electric circuit. Dependent on the discretization, the intrinsic degeneracy of the system can be canceled for the discrete variational scheme. In this way, a variational integrator is constructed that gains several advantages compared to standard integration tools for circuits; in particular, a comparison to BDF methods (which are usually the method of choice for the simulation of electric circuits) shows that even for simple LCR circuits, a better energy behavior and frequency spectrum preservation can be observed using the developed variational integrator

  10. Design of a Long-distance Remote Control Switch Circuit%远距离遥控开关电路设计

    Institute of Scientific and Technical Information of China (English)

    李加旺

    2013-01-01

    实现远距离遥控功能,借助通信网络较易实现。利用解码芯片MC145436及通用编解码器PT2262/PT2272实现对多路开关进行独立遥控的设计方法,具有电路简单、工作可靠、操作方便等优点。%It is easy to realize remote control function by means of communication network. The design methods using the decoder chip MC145436 and universal codec PT2262/PT2272 to achieve multi-channel switch for independent remote control has the advantages of simple circuit, reliable work, and convenient operation etc..

  11. Feasibility study and uncertainties in the validation of an existing safety-related control circuit with the ISO 13849-1:2006 design standard

    International Nuclear Information System (INIS)

    In industry, machine users and people who modify or integrate equipment often have to evaluate the safety level of a safety-related control circuit that they have not necessarily designed. The modifications or integrations may involve work to make an existing machine that does not comply with normative or regulatory specifications safe. However, how can a circuit performing a safety function be validated a posteriori? Is the validation exercise feasible? What are the difficulties and limitations of such a procedure? The aim of this article is to answer these questions by presenting a validation study of a safety function of an existing machine. A plastic injection molding machine is used for this study, as well as standard ISO 13849-1:2006. Validation consists of performing an a posteriori (post-design) estimation of the performance level of the safety function. The procedure is studied for two contexts of use of the machine: in industry, and in laboratory. The calculations required by the ISO standard were done using Excel, followed by SIStema software. It is shown that, based on the context of use, the estimated performance level was different for the same safety-related circuit. The variability in the results is explained by the assumptions made by the person undertaking the validation without the involvement of the machine designer. - Highlights: • Validation of the performance level of a safety function is undertaken. • An injection molding machine and ISO 13849-1:2006 standard are used for the procedure. • The procedure is undertaken for two contexts of use of the machine. • In this study, the performance level depends on the context of use. • The assumptions made throughout the study partially explain this difference

  12. Regrowing the adult brain: NF-κB controls functional circuit formation and tissue homeostasis in the dentate gyrus.

    Directory of Open Access Journals (Sweden)

    Yvonne Imielski

    Full Text Available Cognitive decline during aging is correlated with a continuous loss of cells within the brain and especially within the hippocampus, which could be regenerated by adult neurogenesis. Here we show that genetic ablation of NF-κB resulted in severe defects in the neurogenic region (dentate gyrus of the hippocampus. Despite increased stem cell proliferation, axogenesis, synaptogenesis and neuroprotection were hampered, leading to disruption of the mossy fiber pathway and to atrophy of the dentate gyrus during aging. Here, NF-κB controls the transcription of FOXO1 and PKA, regulating axogenesis. Structural defects culminated in behavioral impairments in pattern separation. Re-activation of NF-κB resulted in integration of newborn neurons, finally to regeneration of the dentate gyrus, accompanied by a complete recovery of structural and behavioral defects. These data identify NF-κB as a crucial regulator of dentate gyrus tissue homeostasis suggesting NF-κB to be a therapeutic target for treating cognitive and mood disorders.

  13. The architecture of the active surface control system of the Large Millimeter Telescope

    Science.gov (United States)

    Souccar, Kamal; Wallace, Gary; Grosslein, Ron; Schloerb, F. Peter

    2014-07-01

    One of the fundamental design principles of the LMT is that its segmented primary surface must be active: the position and orientation of each of the segments must be moved in order to maintain the precise parabolic surface that is required by the specifications. Consequently, a system of actuators, one at the corner of each segment, is used to move the segments to counteract surface deformations attributed to gravity or thermal effects. A new control system was designed and built within the project to implement an active surface at the LMT. The technical concept for the active surface control system is to provide a set of bus boxes with built-in control and I/O capabilities to run four actuators each. Bus boxes read the LVDT sensor position and limit switch status for each actuator and use this information to drive the actuator's DC motor, closing the position loop. Each bus box contains a DC power supply for the electronics, a second DC power supply for the motors, an embedded controller with I/O to close the position loop, and a custom printed circuit board to condition the LVDT signals and drive the motors. An interface printed circuit board resides in each actuator providing a single connector access to the LVDT, the motor, and the limit switches. During the fall of 2013, 84 bus boxes were commissioned to control the 336 actuators of the inner three rings of the telescope. The surface correction model was determined using holography measurements and the active surface system has been in regular use during the scientific observation at the LMT.

  14. Analog circuit design designing dynamic circuit response

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    This second volume, Designing Dynamic Circuit Response builds upon the first volume Designing Amplifier Circuits by extending coverage to include reactances and their time- and frequency-related behavioral consequences.

  15. Childhood physical abuse predicts stressor-evoked activity within central visceral control regions.

    Science.gov (United States)

    Banihashemi, Layla; Sheu, Lei K; Midei, Aimee J; Gianaros, Peter J

    2015-04-01

    Early life experience differentially shapes later stress reactivity, as evidenced by both animal and human studies. However, early experience-related changes in the function of central visceral neural circuits that control stress responses have not been well characterized, particularly in humans. The paraventricular nucleus of the hypothalamus (PVN), bed nucleus of the stria terminalis (BNST), amygdala (Amyg) and subgenual anterior cingulate cortex (sgACC) form a core visceral stress-responsive circuit. The goal of this study is to examine how childhood emotional and physical abuse relates to adulthood stressor-evoked activity within these visceral brain regions. To evoke acute states of mental stress, participants (n = 155) performed functional magnetic resonance imaging (fMRI)-adapted versions of the multi-source interference task (MSIT) and the Stroop task with simultaneous monitoring of mean arterial pressure (MAP) and heart rate. Regression analyses revealed that childhood physical abuse correlated positively with stressor-evoked changes in MAP, and negatively with unbiased, a priori extractions of fMRI blood-oxygen level-dependent signal change values within the sgACC, BNST, PVN and Amyg (n = 138). Abuse-related changes in the function of visceral neural circuits may reflect neurobiological vulnerability to adverse health outcomes conferred by early adversity. PMID:24847113

  16. Experience with chemistry control of primary circuit and operation of high temperature and high pressure mechanical filtration at Temelin VVER-1000/320 NPP

    International Nuclear Information System (INIS)

    The primary circuit with the VVER1000-320V reactor installed in the nuclear power plant Temelin represents a world-unique technology in terms of reduction of concentration of corrosion products and activated corrosion products by means of mechanical, high-temperature and high-pressure filters. The technology uses continual filtration and its main advantage is cleaning of the primary coolant at operating parameters, i.e. without any adjustments of pressure and temperature of the filtered coolant. The filter is made of especially treated titanium, whose spongy form improves the required interception of undissolved corrosion products and activated corrosion products on its surface. It contributes to limitation of formation of radiation fields and it favorably affects reduction of the effective dose received by the plant's operating personnel. (author)

  17. Photomultiplier blanking circuit

    Science.gov (United States)

    Mcclenahan, J. O.

    1972-01-01

    Circuit for protecting photomultiplier equipment from current surges which occur when exposed to brilliant illumination is discussed. Components of circuit and details of operation are provided. Circuit diagram to show action of blanking pulse on zener diode is included.

  18. Prediction control of active power filters

    Institute of Scientific and Technical Information of China (English)

    王莉娜; 罗安

    2003-01-01

    A prediction method to obtain harmonic reference for active power filter is presented. It is a new use ofthe adaptive predictive filter based on FIR. The delay inherent in digital controller is successfully compensated by u-sing the proposed method, and the computing load is not very large compared with the conventional method. Moreo-ver, no additional hardware is needed. Its DSP-based realization is also presented, which is characterized by time-va-riant rate sampling, quasi synchronous sampling, and synchronous operation among the line frequency, PWM gener-ating and sampling in A/D unit. Synchronous operation releases the limitation on PWM modulation ratio and guar-antees that the electrical noises resulting from the switching operation of IGBTs do not interfere with the sampledcurrent. The simulation and experimental results verify the satisfactory performance of the proposed method.

  19. Dysregulated neuronal activity patterns implicate corticostriatal circuit dysfunction in multiple rodent models of Huntington’s disease

    Directory of Open Access Journals (Sweden)

    Benjamin R. Miller

    2011-05-01

    Full Text Available Huntington’s disease (HD is an autosomal dominant neurodegenerative disorder that targets the corticostriatal system and results in progressive deterioration of cognitive, emotional, and motor skills. Although cortical and striatal neurons are widely studied in animal models of HD, there is little information on neuronal function during expression of the HD behavioral phenotype. To address this knowledge gap, we used chronically implanted micro-wire bundles to record extracellular spikes and local field potentials (LFPs in truncated (R6/1 and R6/2 and full-length (knock-in, KI mouse models as well as in tgHD rats behaving in an open-field arena. Spike activity was recorded in the striatum of all models and in prefrontal cortex (PFC of R6/2 and KI mice, and in primary motor cortex (M1 of R6/2 mice. We also recorded LFP activity in R6/2 striatum. All HD models exhibited altered neuronal activity relative to wild-type (WT controls. Although there was no consistent effect on firing rate across models and brain areas, burst firing was reduced in striatum, PFC, and M1 of R6/2 mice, and in striatum of KI mice. Consistent with a decline in bursting, the interspike-interval coefficient of variation was reduced in all regions of all models, except PFC of KI mice and striatum of tgHD rats. Among simultaneously recorded neuron pairs, correlated firing was reduced in all brain regions of all models, while coincident bursting, which measures the temporal overlap between bursting pairs, was reduced in striatum of all models as well as in M1 of R6/2's. Preliminary analysis of striatal LFPs revealed aberrant behavior-related oscillations in the delta to theta range and in gamma activity. Collectively, our results indicate that disrupted corticostriatal processing occurs across multiple HD models despite differences in the severity of the behavioral phenotype. Efforts aimed at normalizing corticostriatal activity may hold the key to developing new HD

  20. Missile flight control using active flexspar actuators

    Science.gov (United States)

    Barrett, Ron; Gross, R. Steven; Brozoski, Fred

    1996-04-01

    A new type of subsonic missile flight control surface using piezoelectric flexspar actuators is presented. The flexspar design uses an aerodynamic shell which is pivoted at the quarter-chord about a graphite main spar. The shell is pitched up and down by a piezoelectric bender element which is rigidly attached to a base mount and allowed to rotate freely at the tip. The element curvature, shell pitch deflection and torsional stiffness are modeled using laminated plate theory. A one-third scale TOW 2B missile model was used as a demonstration platform. A static wing of the missile was replaced with an active flexspar wing. The 1 in 0964-1726/5/2/002/img1 2.7 in active flight control surface was powered by a bimorph bender with 5 mil PZT-5H sheets. Bench and wind tunnel testing showed good correlation between theory and experiment and static pitch deflections in excess of 0964-1726/5/2/002/img2. A natural frequency of 78.5 rad 0964-1726/5/2/002/img3 with a break frequency of 157 rad 0964-1726/5/2/002/img3 was measured. Wind tunnel tests revealed no flutter or divergence tendencies. Maximum changes in lift coefficient were measured at 0964-1726/5/2/002/img5 which indicates that terminal and initial missile load factors may be increased by approximately 3.1 and 12.6 g respectively, leading to a greatly reduced turn radius of only 2400 ft.