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Sample records for combinational circuits based

  1. Resistor Combinations for Parallel Circuits.

    ERIC Educational Resources Information Center

    McTernan, James P.

    1978-01-01

    To help simplify both teaching and learning of parallel circuits, a high school electricity/electronics teacher presents and illustrates the use of tables of values for parallel resistive circuits in which total resistances are whole numbers. (MF)

  2. Minutiae matching with privacy protection based on the combination of garbled circuit and homomorphic encryption.

    PubMed

    Li, Mengxing; Feng, Quan; Zhao, Jian; Yang, Mei; Kang, Lijun; Wu, Lili

    2014-01-01

    Biometrics plays an important role in authentication applications since they are strongly linked to holders. With an increasing growth of e-commerce and e-government, one can expect that biometric-based authentication systems are possibly deployed over the open networks in the near future. However, due to its openness, the Internet poses a great challenge to the security and privacy of biometric authentication. Biometric data cannot be revoked, so it is of paramount importance that biometric data should be handled in a secure way. In this paper we present a scheme achieving privacy-preserving fingerprint authentication between two parties, in which fingerprint minutiae matching algorithm is completed in the encrypted domain. To improve the efficiency, we exploit homomorphic encryption as well as garbled circuits to design the protocol. Our goal is to provide protection for the security of template in storage and data privacy of two parties in transaction. The experimental results show that the proposed authentication protocol runs efficiently. Therefore, the protocol can run over open networks and help to alleviate the concerns on security and privacy of biometric applications over the open networks. PMID:24711729

  3. Minutiae Matching with Privacy Protection Based on the Combination of Garbled Circuit and Homomorphic Encryption

    PubMed Central

    Li, Mengxing; Zhao, Jian; Yang, Mei; Kang, Lijun; Wu, Lili

    2014-01-01

    Biometrics plays an important role in authentication applications since they are strongly linked to holders. With an increasing growth of e-commerce and e-government, one can expect that biometric-based authentication systems are possibly deployed over the open networks in the near future. However, due to its openness, the Internet poses a great challenge to the security and privacy of biometric authentication. Biometric data cannot be revoked, so it is of paramount importance that biometric data should be handled in a secure way. In this paper we present a scheme achieving privacy-preserving fingerprint authentication between two parties, in which fingerprint minutiae matching algorithm is completed in the encrypted domain. To improve the efficiency, we exploit homomorphic encryption as well as garbled circuits to design the protocol. Our goal is to provide protection for the security of template in storage and data privacy of two parties in transaction. The experimental results show that the proposed authentication protocol runs efficiently. Therefore, the protocol can run over open networks and help to alleviate the concerns on security and privacy of biometric applications over the open networks. PMID:24711729

  4. Memristor based startup circuit for self biased circuits

    NASA Astrophysics Data System (ADS)

    Das, Mangal; Singh, Amit Kumar; Rathi, Amit; Singhal, Sonal

    2016-04-01

    This paper presents the design of a Memristor based startup circuit for self biased circuits. Memristor has many advantages over conventional CMOS devices such as low leakage current at nanometer scale, easy to manufacture. In this work the switching characteristics of memristor is utilized. First the theoretical equations describing the switching behavior of memristor are investigated. To prove the switching capability of Memristor, a startup circuit based on memristor is proposed which uses series combination of Memristor and capacitor. Proposed circuit is compared with the previously reported MOSFET based startup circuits. Comparison of different circuits was done to validate the results. Simulation results show that memristor based circuit can attain on (I = 12.94 µA) to off state (I = 1 .2 µA) in 25 ns while the MOSFET based startup circuits take on (I = 14.19 µA) to off state (I = 1.4 µA) in more than 90 ns. The benefit comes in terms of area because the number of components used in the circuit are lesser than the conventional startup circuits.

  5. Global Electric Circuit Implications of Combined Aircraft Storm Electric Current Measurements and Satellite-Based Diurnal Lightning Statistics

    NASA Technical Reports Server (NTRS)

    Mach, Douglas M.; Blakeslee, Richard J.; Bateman, Monte G.

    2011-01-01

    Using rotating vane electric field mills and Gerdien capacitors, we measured the electric field profile and conductivity during 850 overflights of thunderstorms and electrified shower clouds (ESCs) spanning regions including the Southeastern United States, the Western Atlantic Ocean, the Gulf of Mexico, Central America and adjacent oceans, Central Brazil, and the South Pacific. The overflights include storms over land and ocean, and with positive and negative fields above the storms. Over three-quarters (78%) of the land storms had detectable lightning, while less than half (43%) of the oceanic storms had lightning. Integrating our electric field and conductivity data, we determined total conduction currents and flash rates for each overpass. With knowledge of the storm location (land or ocean) and type (with or without lightning), we determine the mean currents by location and type. The mean current for ocean thunderstorms is 1.7 A while the mean current for land thunderstorms is 1.0 A. The mean current for ocean ESCs 0.41 A and the mean current for land ESCs is 0.13 A. We did not find any significant regional or latitudinal based patterns in our total conduction currents. By combining the aircraft derived storm currents and flash rates with diurnal flash rate statistics derived from the Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) low Earth orbiting satellites, we reproduce the diurnal variation in the global electric circuit (i.e., the Carnegie curve) to within 4% for all but two short periods of time. The agreement with the Carnegie curve was obtained without any tuning or adjustment of the satellite or aircraft data. Given our data and assumptions, mean contributions to the global electric circuit are 1.1 kA (land) and 0.7 kA (ocean) from thunderstorms, and 0.22 kA (ocean) and 0.04 (land) from ESCs, resulting in a mean total conduction current estimate for the global electric circuit of 2.0 kA. Mean storm counts are 1100 for land

  6. Base drive circuit

    DOEpatents

    Lange, Arnold C.

    1995-01-01

    An improved base drive circuit (10) having a level shifter (24) for providing bistable input signals to a pair of non-linear delays (30, 32). The non-linear delays (30, 32) provide gate control to a corresponding pair of field effect transistors (100, 106) through a corresponding pair of buffer components (88, 94). The non-linear delays (30, 32) provide delayed turn-on for each of the field effect transistors (100, 106) while an associated pair of transistors (72, 80) shunt the non-linear delays (30, 32) during turn-off of the associated field effect transistor (100, 106).

  7. Base drive circuit

    DOEpatents

    Lange, A.C.

    1995-04-04

    An improved base drive circuit having a level shifter for providing bistable input signals to a pair of non-linear delays. The non-linear delays provide gate control to a corresponding pair of field effect transistors through a corresponding pair of buffer components. The non-linear delays provide delayed turn-on for each of the field effect transistors while an associated pair of transistors shunt the non-linear delays during turn-off of the associated field effect transistor. 2 figures.

  8. Identification of functional components in combinational circuits

    SciTech Connect

    Doom, T.E.; White, J.L.; Wojcik, A.S.; Chisholm, G.H.

    1998-01-01

    Identifying the subcircuits in a detailed circuit description is a fundamental operation in both circuit validation and design recovery. Existing identification techniques rely on finding an exact match for a subcircuit structure within the description. These techniques fail to identify subcircuits that are functionally equivalent but have been obfuscated because a different technology is being used or because the design has been optimized. This report presents a mechanism for identifying subcircuits that are functionally equivalent, irrespective of obfuscating details. It also describes the initial progress made in transforming detailed circuit descriptions into corresponding descriptions based on subcircuits. Such progress depends on enumerating all of the candidate subcircuits within the original detailed description and functionally matching each candidate. The report presents unique solutions for reducing the amount of computation needed for this enumeration.

  9. Synthesis of Genetic Clock with Combinational Biologic Circuits.

    PubMed

    Chen, Po-Kuei; Lin, Chun-Liang

    2015-01-01

    The potential of genetic clock lies in its role to triggering logic reaction for sequential biological circuits. In general, biochemical reaction of the biological system is extremely slow. However, a square wave generator used as a genetic clock the transient response should be fast enough to catch the reaction change between two logic levels. Therefore, the requirement for instantaneous changes in logic status is not likely to exist in biological systems. This paper presents a method of synthesizing a genetic clock generator based on the combination of a toggle switch with two biological logic gates. A dual repressor is used to connect the two fundamental biologic circuits. Analysis of the characteristic responses of this genetic clock with its relation to the key parameters is provided. PMID:26451832

  10. W-band, 20 W microstrip integrated circuit combiner

    NASA Astrophysics Data System (ADS)

    Yen, Y. E.; Hayashibara, G.; Yen, P.; Ngan, Y. C.; Yen, H. C.

    1987-04-01

    A W-band, 20 W, short-pulse microstrip integrated circuit (MIC) power combiner was developed, adopting an integrated circuit design approach in conjunction with a versatile modulator to achieve small size, low cost, and high performance. The combiner consists of two high power IMPATT oscillators and a low-loss ratrace ring hybrid circuit. Using a high power diode in a well-matched circuit, an individual MIC IMPATT oscillator delivered 12.5 W with less than 1.5 dB degradation from rated waveguide power. The insertion loss of the ratrace ring circuit is 0.75 dB. A circulator is not required. Furthermore, well balanced amplitude and phase relationships ensure that the combined power emerges only at the output port. The combiner efficiency exceeds 80 percent. The DC-to-RF conversion efficiency is about 3 percent. The pulsewidth and pulse repetition rate are 40 ns and 80 kHz, respectively.

  11. Effect of solvent and additives on the open-circuit voltage of ZnO-based dye-sensitized solar cells: a combined theoretical and experimental study.

    PubMed

    Le Bahers, Tangui; Labat, Frédéric; Pauporté, Thierry; Ciofini, Ilaria

    2010-11-28

    We have investigated the role of electrolyte composition, in terms of solvent and additive, on the open-circuit voltage (V(oc)) of ZnO-based dye-sensitized solar cells (DSSCs) using a combined experimental and theoretical approach. Calculations based on density functional theory (DFT) have been performed in order to describe the geometries and adsorption energies of various adsorbed solvents (nitromethane, acetonitrile and dimethylformamide) and p-tert-butylpyridine (TBP) (modeled by methylpyridine) on the ZnO (100) surface using a periodic approach. The densities of states (DOS) have been calculated and the energy position of the conduction band edge (CBE) has been evaluated for the different molecules adsorbed. The effect of the electrolyte composition on the standard redox potential of the iodide/triiodide redox couple has been experimentally determined. These two data values (CBE and standard redox potential) allowed us to determine the dependence of V(oc) on the electrolyte composition. The variations determined using this method were in good agreement with the measured V(oc) for cells made of electrodeposited ZnO films sensitized using D149 (indoline) dye. As in the case of TiO(2)-based cells, a correlation of V(oc) with the donor number of the adsorbed species was found. The present study clearly points out that both the CBE energy and the redox potential variation are important for explaining the experimentally observed changes in the V(oc) of DSSCs. PMID:20949189

  12. Combining Different Conceptual Change Methods within Four-Step Constructivist Teaching Model: A Sample Teaching of Series and Parallel Circuits

    ERIC Educational Resources Information Center

    Ipek, Hava; Calik, Muammer

    2008-01-01

    Based on students' alternative conceptions of the topics "electric circuits", "electric charge flows within an electric circuit", "how the brightness of bulbs and the resistance changes in series and parallel circuits", the current study aims to present a combination of different conceptual change methods within a four-step constructivist teaching…

  13. Memristor based-elements for chaotic circuits

    NASA Astrophysics Data System (ADS)

    Corinto, Fernando; Ascoli, Alon

    The peculiar features of the memristor, a fundamental passive two-terminal element characterized by nonlinear relationship between charge and flux, promise to revolutionize integrated circuit design in the next few decades. Besides its most popular potential applications, ultra-dense non-volatile memories and brain-simulating systems, much research has been lately devoted to their use in chaotic circuits. Although the physical memristor is inherently-asymmetric, complementary behaviors arise in devices with opposite polarity. In this work we demonstrate that this makes it feasible to devise a number of practical realizations of a monotone-increasing odd-symmetric charge-flux nonlinearity suitable for chaos-based applications through the sole use of physical memristors of the kind recently fabricated at Hewlett-Packard Labs. Confirmation for such claim is obtained through comparison of chaotic behavior of two modified Chua's oscillators, in which the nonlinear diode is replaced in one case with an artificial memristor with symmetric nonlinearity and in the other case with one of the proposed symmetric memristor combinations.

  14. Organic reprogrammable circuits based on electrochemically formed diodes.

    PubMed

    Liu, Jiang; Engquist, Isak; Berggren, Magnus

    2014-08-13

    We report a method to construct reprogrammable circuits based on organic electrochemical (EC) p-n junction diodes. The diodes are built up from the combination of the organic conjugated polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] and a polymer electrolyte. The p-n diodes are defined by EC doping performed at 70 °C, and then stabilized at -30 °C. The reversible EC reaction allows for in situ reprogramming of the polarity of the organic p-n junction, thus enabling us to reconfigure diode circuits. By combining diodes of specific polarities dedicated circuits have been created, such as various logic gates, a voltage limiter and an AC/DC converter. Reversing the EC reaction allows in situ reprogramming of the p-n junction polarity, thus enabling reconfiguration of diode circuits, for example, from an AND gate to an OR gate. The reprogrammable circuits are based on p-n diodes defined from only two layers, the electrodes and then the active semiconductor:electrolyte composite material. Such simple device structures are promising for large-area and fully printed reconfigurable circuits manufactured using common printing tools. The structure of the reported p-n diodes mimics the architecture of and is based on identical materials used to construct light-emitting electrochemical cells (LEC). Our findings thus provide a robust signal routing technology that is easily integrated with traditional LECs.

  15. Organic reprogrammable circuits based on electrochemically formed diodes.

    PubMed

    Liu, Jiang; Engquist, Isak; Berggren, Magnus

    2014-08-13

    We report a method to construct reprogrammable circuits based on organic electrochemical (EC) p-n junction diodes. The diodes are built up from the combination of the organic conjugated polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] and a polymer electrolyte. The p-n diodes are defined by EC doping performed at 70 °C, and then stabilized at -30 °C. The reversible EC reaction allows for in situ reprogramming of the polarity of the organic p-n junction, thus enabling us to reconfigure diode circuits. By combining diodes of specific polarities dedicated circuits have been created, such as various logic gates, a voltage limiter and an AC/DC converter. Reversing the EC reaction allows in situ reprogramming of the p-n junction polarity, thus enabling reconfiguration of diode circuits, for example, from an AND gate to an OR gate. The reprogrammable circuits are based on p-n diodes defined from only two layers, the electrodes and then the active semiconductor:electrolyte composite material. Such simple device structures are promising for large-area and fully printed reconfigurable circuits manufactured using common printing tools. The structure of the reported p-n diodes mimics the architecture of and is based on identical materials used to construct light-emitting electrochemical cells (LEC). Our findings thus provide a robust signal routing technology that is easily integrated with traditional LECs. PMID:24998703

  16. Chemoelectronic circuits based on metal nanoparticles.

    PubMed

    Yan, Yong; Warren, Scott C; Fuller, Patrick; Grzybowski, Bartosz A

    2016-07-01

    To develop electronic devices with novel functionalities and applications, various non-silicon-based materials are currently being explored. Nanoparticles have unique characteristics due to their small size, which can impart functions that are distinct from those of their bulk counterparts. The use of semiconductor nanoparticles has already led to improvements in the efficiency of solar cells, the processability of transistors and the sensitivity of photodetectors, and the optical and catalytic properties of metal nanoparticles have led to similar advances in plasmonics and energy conversion. However, metals screen electric fields and this has, so far, prevented their use in the design of all-metal nanoparticle circuitry. Here, we show that simple electronic circuits can be made exclusively from metal nanoparticles functionalized with charged organic ligands. In these materials, electronic currents are controlled by the ionic gradients of mobile counterions surrounding the 'jammed' nanoparticles. The nanoparticle-based electronic elements of the circuitry can be interfaced with metal nanoparticles capable of sensing various environmental changes (humidity, gas, the presence of various cations), creating electronic devices in which metal nanoparticles sense, process and ultimately report chemical signals. Because the constituent nanoparticles combine electronic and chemical sensing functions, we term these systems 'chemoelectronic'. The circuits have switching times comparable to those of polymer electronics, selectively transduce parts-per-trillion chemical changes into electrical signals, perform logic operations, consume little power (on the scale of microwatts), and are mechanically flexible. They are also 'green', in the sense that they comprise non-toxic nanoparticles cast at room temperature from alcohol solutions. PMID:26974958

  17. Chemoelectronic circuits based on metal nanoparticles

    NASA Astrophysics Data System (ADS)

    Yan, Yong; Warren, Scott C.; Fuller, Patrick; Grzybowski, Bartosz A.

    2016-07-01

    To develop electronic devices with novel functionalities and applications, various non-silicon-based materials are currently being explored. Nanoparticles have unique characteristics due to their small size, which can impart functions that are distinct from those of their bulk counterparts. The use of semiconductor nanoparticles has already led to improvements in the efficiency of solar cells, the processability of transistors and the sensitivity of photodetectors, and the optical and catalytic properties of metal nanoparticles have led to similar advances in plasmonics and energy conversion. However, metals screen electric fields and this has, so far, prevented their use in the design of all-metal nanoparticle circuitry. Here, we show that simple electronic circuits can be made exclusively from metal nanoparticles functionalized with charged organic ligands. In these materials, electronic currents are controlled by the ionic gradients of mobile counterions surrounding the ‘jammed’ nanoparticles. The nanoparticle-based electronic elements of the circuitry can be interfaced with metal nanoparticles capable of sensing various environmental changes (humidity, gas, the presence of various cations), creating electronic devices in which metal nanoparticles sense, process and ultimately report chemical signals. Because the constituent nanoparticles combine electronic and chemical sensing functions, we term these systems ‘chemoelectronic’. The circuits have switching times comparable to those of polymer electronics, selectively transduce parts-per-trillion chemical changes into electrical signals, perform logic operations, consume little power (on the scale of microwatts), and are mechanically flexible. They are also ‘green’, in the sense that they comprise non-toxic nanoparticles cast at room temperature from alcohol solutions.

  18. The Effect of Combining Analogy-Based Simulation and Laboratory Activities on Turkish Elementary School Students' Understanding of Simple Electric Circuits

    ERIC Educational Resources Information Center

    Unlu, Zeynep Koyunlu; Dokme, Ibilge

    2011-01-01

    The purpose of this study was to investigate whether the combination of both analogy-based simulation and laboratory activities as a teaching tool was more effective than utilizing them separately in teaching the concepts of simple electricity. The quasi-experimental design that involved 66 seventh grade students from urban Turkish elementary…

  19. The development of an uncommitted integrated circuit for combined digital and analogue applications

    NASA Astrophysics Data System (ADS)

    Kemp, A. J.

    1982-06-01

    An uncommmited integrated circuit is a standardized integrated circuit needing only a fraction of the normal processing steps to program it for a required application. The result is a reduction in the time, money and knowledge required to develop an integrated circuit. The development and industrialization of an uncommitted circuit for combined digital and analog applications are described. Integrated Injection Logic (I2L) is used to realize digital functions, and standard analog techniques, based on a bipolar process, are used to realize analog functions. A novel architecture, as well as the use of three masks to realize a required interconnection pattern, results in a very high efficiency in terms of the number of components that was used.

  20. The Papez Circuit in First-Episode, Treatment-Naive Adults with Major Depressive Disorder: Combined Atlas-Based Tract-Specific Quantification Analysis and Voxel-Based Analysis

    PubMed Central

    Jiang, Wenyan; Gong, Gaolang; Wu, Feng; Kong, Lingtao; Chen, Kaiyuan; Cui, Wenhui; Ren, Ling; Fan, Guoguang; Sun, Wenge; Ma, Huan; Xu, Ke; Tang, Yanqing; Wang, Fei

    2015-01-01

    Previous findings suggest that the Papez Circuit may have a role in major depressive disorders. We used atlas-based tract-specific quantification analysis and voxel-based analysis to examine the integrity of white matter tracts involved in mood regulation (including tracts in the Papez Circuit). Diffusion tensor imaging acquired from 35 first-episode, treatment-naive adults with major depressive disorders and 34 healthy adult controls were compared. Our statistical approach compared structural integrity of 11 major white matter tracts between the major depressive disorder and adult controls, as well as illness duration influence in patients. Fractional anisotropy was decreased in the hippocampal cingulum and in the anterior thalamic radiation according to both analytical approaches, all of which were important tracts included in the Papez Circuit. Our results support the role of the Papez Circuit in major depressive disorders with the minimal probability of false positive due to similar findings in both analyses that have complementary advantages. Dysfunction of the Papez Circuit may be a potential marker for studying the pathogenesis of major depressive disorders. PMID:25996480

  1. The papez circuit in first-episode, treatment-naive adults with major depressive disorder: combined atlas-based tract-specific quantification analysis and voxel-based analysis.

    PubMed

    Jiang, Wenyan; Gong, Gaolang; Wu, Feng; Kong, Lingtao; Chen, Kaiyuan; Cui, Wenhui; Ren, Ling; Fan, Guoguang; Sun, Wenge; Ma, Huan; Xu, Ke; Tang, Yanqing; Wang, Fei

    2015-01-01

    Previous findings suggest that the Papez Circuit may have a role in major depressive disorders. We used atlas-based tract-specific quantification analysis and voxel-based analysis to examine the integrity of white matter tracts involved in mood regulation (including tracts in the Papez Circuit). Diffusion tensor imaging acquired from 35 first-episode, treatment-naive adults with major depressive disorders and 34 healthy adult controls were compared. Our statistical approach compared structural integrity of 11 major white matter tracts between the major depressive disorder and adult controls, as well as illness duration influence in patients. Fractional anisotropy was decreased in the hippocampal cingulum and in the anterior thalamic radiation according to both analytical approaches, all of which were important tracts included in the Papez Circuit. Our results support the role of the Papez Circuit in major depressive disorders with the minimal probability of false positive due to similar findings in both analyses that have complementary advantages. Dysfunction of the Papez Circuit may be a potential marker for studying the pathogenesis of major depressive disorders.

  2. Nonlinear dynamics based digital logic and circuits

    PubMed Central

    Kia, Behnam; Lindner, John. F.; Ditto, William L.

    2015-01-01

    We discuss the role and importance of dynamics in the brain and biological neural networks and argue that dynamics is one of the main missing elements in conventional Boolean logic and circuits. We summarize a simple dynamics based computing method, and categorize different techniques that we have introduced to realize logic, functionality, and programmability. We discuss the role and importance of coupled dynamics in networks of biological excitable cells, and then review our simple coupled dynamics based method for computing. In this paper, for the first time, we show how dynamics can be used and programmed to implement computation in any given base, including but not limited to base two. PMID:26029096

  3. Printed organic thin-film transistor-based integrated circuits

    NASA Astrophysics Data System (ADS)

    Mandal, Saumen; Noh, Yong-Young

    2015-06-01

    Organic electronics is moving ahead on its journey towards reality. However, this technology will only be possible when it is able to meet specific criteria including flexibility, transparency, disposability and low cost. Printing is one of the conventional techniques to deposit thin films from solution-based ink. It is used worldwide for visual modes of information, and it is now poised to enter into the manufacturing processes of various consumer electronics. The continuous progress made in the field of functional organic semiconductors has achieved high solubility in common solvents as well as high charge carrier mobility, which offers ample opportunity for organic-based printed integrated circuits. In this paper, we present a comprehensive review of all-printed organic thin-film transistor-based integrated circuits, mainly ring oscillators. First, the necessity of all-printed organic integrated circuits is discussed; we consider how the gap between printed electronics and real applications can be bridged. Next, various materials for printed organic integrated circuits are discussed. The features of these circuits and their suitability for electronics using different printing and coating techniques follow. Interconnection technology is equally important to make this product industrially viable; much attention in this review is placed here. For high-frequency operation, channel length should be sufficiently small; this could be achievable with a combination of surface treatment-assisted printing or laser writing. Registration is also an important issue related to printing; the printed gate should be perfectly aligned with the source and drain to minimize parasitic capacitances. All-printed organic inverters and ring oscillators are discussed here, along with their importance. Finally, future applications of all-printed organic integrated circuits are highlighted.

  4. Base drive and overlap protection circuit

    DOEpatents

    Gritter, David J.

    1983-01-01

    An inverter (34) which provides power to an A. C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A. C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A. C. machine is optimized. The control circuit includes a microcomputer and memory element which receive various parametric inputs and calculate optimized machine control data signals therefrom. The control data is asynchronously loaded into the inverter through an intermediate buffer (38). A base drive and overlap protection circuit is included to insure that both transistors of a complimentary pair are not conducting at the same time. In its preferred embodiment, the present invention is incorporated within an electric vehicle (10) employing a 144 VDC battery pack (32) and a three-phase induction motor (18).

  5. OptCircuit: An optimization based method for computational design of genetic circuits

    PubMed Central

    Dasika, Madhukar S; Maranas, Costas D

    2008-01-01

    Background Recent years has witnessed an increasing number of studies on constructing simple synthetic genetic circuits that exhibit desired properties such as oscillatory behavior, inducer specific activation/repression, etc. It has been widely acknowledged that that task of building circuits to meet multiple inducer-specific requirements is a challenging one. This is because of the incomplete description of component interactions compounded by the fact that the number of ways in which one can chose and interconnect components, increases exponentially with the number of components. Results In this paper we introduce OptCircuit, an optimization based framework that automatically identifies the circuit components from a list and connectivity that brings about the desired functionality. Multiple literature sources are used to compile a comprehensive compilation of kinetic descriptions of promoter-protein pairs. The dynamics that govern the interactions between the elements of the genetic circuit are currently modeled using deterministic ordinary differential equations but the framework is general enough to accommodate stochastic simulations. The desired circuit response is abstracted as the maximization/minimization of an appropriately constructed objective function. Computational results for a toggle switch example demonstrate the ability of the framework to generate the complete list of circuit designs of varying complexity that exhibit the desired response. Designs identified for a genetic decoder highlight the ability of OptCircuit to suggest circuit configurations that go beyond the ones compatible with digital logic-based design principles. Finally, the results obtained from the concentration band detector example demonstrate the ability of OptCircuit to design circuits whose responses are contingent on the level of external inducer as well as pinpoint parameters for modification to rectify an existing (non-functional) biological circuit and restore

  6. All-semiconductor metamaterial-based optical circuit board at the microscale

    SciTech Connect

    Min, Li; Huang, Lirong

    2015-07-07

    The newly introduced metamaterial-based optical circuit, an analogue of electronic circuit, is becoming a forefront topic in the fields of electronics, optics, plasmonics, and metamaterials. However, metals, as the commonly used plasmonic elements in an optical circuit, suffer from large losses at the visible and infrared wavelengths. We propose here a low-loss, all-semiconductor metamaterial-based optical circuit board at the microscale by using interleaved intrinsic GaAs and doped GaAs, and present the detailed design process for various lumped optical circuit elements, including lumped optical inductors, optical capacitors, optical conductors, and optical insulators. By properly combining these optical circuit elements and arranging anisotropic optical connectors, we obtain a subwavelength optical filter, which can always hold band-stop filtering function for various polarization states of the incident electromagnetic wave. All-semiconductor optical circuits may provide a new opportunity in developing low-power and ultrafast components and devices for optical information processing.

  7. Engineering Gene Circuits for Mammalian Cell-Based Applications.

    PubMed

    Ausländer, Simon; Fussenegger, Martin

    2016-01-01

    Synthetic gene switches are basic building blocks for the construction of complex gene circuits that transform mammalian cells into useful cell-based machines for next-generation biotechnological and biomedical applications. Ligand-responsive gene switches are cellular sensors that are able to process specific signals to generate gene product responses. Their involvement in complex gene circuits results in sophisticated circuit topologies that are reminiscent of electronics and that are capable of providing engineered cells with the ability to memorize events, oscillate protein production, and perform complex information-processing tasks. Microencapsulated mammalian cells that are engineered with closed-loop gene networks can be implanted into mice to sense disease-related input signals and to process this information to produce a custom, fine-tuned therapeutic response that rebalances animal metabolism. Progress in gene circuit design, in combination with recent breakthroughs in genome engineering, may result in tailored engineered mammalian cells with great potential for future cell-based therapies. PMID:27194045

  8. Optical XOR circuit using combined technology of photonics and electronics

    NASA Astrophysics Data System (ADS)

    Takiguchi, Koichi

    2013-12-01

    I propose and demonstrate a novel and simple optical exclusive OR circuit for binary signals, which is composed of a balanced photo-detector and a Mach-Zehnder intensity modulator. Two input optical signals into the photo-detector produce an electrical signal to drive the modulator. The modulator outputs an optical exclusive OR signal of the two input optical signals. I report the configuration, operating principle, and primary experimental results using 10 Gbit/s binary signals to demonstrate that the exclusive OR circuit operates properly. The proposed simple circuit is suitable for the future hybrid integration of photonics and electronics.

  9. Coherent THz wave combiner composed of arrayed uni-traveling carrier photodiodes and planar lightwave circuit

    NASA Astrophysics Data System (ADS)

    Sakuma, K.; Haruki, J.; Sakano, G.; Kato, K.; Hisatake, S.; Nagatsuma, T.

    2016-02-01

    For high-power THz wave generation by photomixing of two lightwaves, we proposed the synchronous power combiner which consists of eight-arrayed photomixers/antennas and the THz phase control system. We experimentally confirmed the effectiveness of the power combination by synchronizing the phases of the THz wave by the mechanical optical delay lines and also demonstrated the same functionality at the lightwave-circuit-based optical phase control system. We found that the directional gain is increasing with increasing the number of photomixers from two to three and it reached up to 4.5 dB.

  10. Reliable interface design for combining asynchronous and synchronous circuits

    NASA Technical Reports Server (NTRS)

    Josephson, Lueli; Brunvand, Erik L.; Gopalakrishan, Ganesh; Hurdle, John F.

    1993-01-01

    In order to successfully integrate asynchronous and synchronous designs, great care must be taken at the interface between the two types of systems. Synchronizing asynchronous inputs with a free running clock can cause well-known problems with metastability in the synchronization circuits. Stretchable clocks allow a clock cycle to expand dynamically in response to the metastability effects of sampling asynchronous inputs. We use an interface organization where the special circuitry for detecting metastability and for stretching the clock that is delivered to the synchronous part of the system is encapsulated in a Q-flop-based interface. This provides a very convenient method for interfacing mixed systems, as the interface and clock generation circuitry are isolated into one special module, and neither the asynchronous nor the synchronous system need be modified internally to accommodate the interface. This is especially important when standard synchronous components are used as there is no opportunity to modify these parts. We show that this interface module is suitable for most mixed design needs and conclude with an example.

  11. Modular packaging technique for combining integrated circuits and discrete components

    NASA Technical Reports Server (NTRS)

    Lacchia, J. F.

    1969-01-01

    Technique for packaging electronic modules interconnects integrated circuits and discrete components by means of beryllium-copper strips in a molded diallyphthalate tray. Simple girder-like construction provides ease of assembly, high rigidity, excellent vibration resistance, and good heat dissipation characteristics.

  12. Efficient G(sup 4)FET-Based Logic Circuits

    NASA Technical Reports Server (NTRS)

    Vatan, Farrokh

    2008-01-01

    A total of 81 optimal logic circuits based on four-gate field-effect transistors (G(sup 4)4FETs) have been designed to implement all Boolean functions of up to three variables. The purpose of this development was to lend credence to the expectation that logic circuits based on G(sup 4)FETs could be more efficient (in the sense that they could contain fewer transistors), relative to functionally equivalent logic circuits based on conventional transistors. A G(sup 4)FET a combination of a junction field-effect transistor (JFET) and a metal oxide/semiconductor field-effect transistor (MOSFET) superimposed in a single silicon island and can therefore be regarded as two transistors sharing the same body. A G(sup 4)FET can also be regarded as a single device having four gates: two side junction-based gates, a top MOS gate, and a back gate activated by biasing of a silicon-on-insulator substrate. Each of these gates can be used to control the conduction characteristics of the transistor; this possibility creates new options for designing analog, radio-frequency, mixed-signal, and digital circuitry. One such option is to design a G(sup 4)FET to function as a three-input NOT-majority gate, which has been shown to be a universal and programmable logic gate. Optimal NOT-majority-gate, G(sup 4)FET-based logic-circuit designs were obtained in a comparative study that also included formulation of functionally equivalent logic circuits based on NOR and NAND gates implemented by use of conventional transistors. In the study, the problem of finding the optimal design for each logic function and each transistor type was solved as an integer-programming optimization problem. Considering all 81 non-equivalent Boolean functions included in the study, it was found that in 63% of the cases, fewer logic gates (and, hence, fewer transistors) would be needed in the G(sup 4)FET-based implementations.

  13. Circuit-based interrogation of sleep control.

    PubMed

    Weber, Franz; Dan, Yang

    2016-10-01

    Sleep is a fundamental biological process observed widely in the animal kingdom, but the neural circuits generating sleep remain poorly understood. Understanding the brain mechanisms controlling sleep requires the identification of key neurons in the control circuits and mapping of their synaptic connections. Technical innovations over the past decade have greatly facilitated dissection of the sleep circuits. This has set the stage for understanding how a variety of environmental and physiological factors influence sleep. The ability to initiate and terminate sleep on command will also help us to elucidate its functions within and beyond the brain.

  14. A chaotic circuit based on Hewlett-Packard memristor

    NASA Astrophysics Data System (ADS)

    Buscarino, Arturo; Fortuna, Luigi; Frasca, Mattia; Valentina Gambuzza, Lucia

    2012-06-01

    Memristors are gaining increasing attention as next generation electronic devices. They are also becoming commonly used as fundamental blocks for building chaotic circuits, although often arbitrary (typically piece-wise linear or cubic) flux-charge characteristics are assumed. In this paper, a chaotic circuit based on the mathematical realistic model of the HP memristor is introduced. The circuit makes use of two HP memristors in antiparallel. Numerical results showing some of the chaotic attractors generated by this circuit and the behavior with respect to changes in its component values are described.

  15. A chaotic circuit based on Hewlett-Packard memristor.

    PubMed

    Buscarino, Arturo; Fortuna, Luigi; Frasca, Mattia; Gambuzza, Lucia Valentina

    2012-06-01

    Memristors are gaining increasing attention as next generation electronic devices. They are also becoming commonly used as fundamental blocks for building chaotic circuits, although often arbitrary (typically piece-wise linear or cubic) flux-charge characteristics are assumed. In this paper, a chaotic circuit based on the mathematical realistic model of the HP memristor is introduced. The circuit makes use of two HP memristors in antiparallel. Numerical results showing some of the chaotic attractors generated by this circuit and the behavior with respect to changes in its component values are described.

  16. A spiking neuron circuit based on a carbon nanotube transistor.

    PubMed

    Chen, C-L; Kim, K; Truong, Q; Shen, A; Li, Z; Chen, Y

    2012-07-11

    A spiking neuron circuit based on a carbon nanotube (CNT) transistor is presented in this paper. The spiking neuron circuit has a crossbar architecture in which the transistor gates are connected to its row electrodes and the transistor sources are connected to its column electrodes. An electrochemical cell is incorporated in the gate of the transistor by sandwiching a hydrogen-doped poly(ethylene glycol)methyl ether (PEG) electrolyte between the CNT channel and the top gate electrode. An input spike applied to the gate triggers a dynamic drift of the hydrogen ions in the PEG electrolyte, resulting in a post-synaptic current (PSC) through the CNT channel. Spikes input into the rows trigger PSCs through multiple CNT transistors, and PSCs cumulate in the columns and integrate into a 'soma' circuit to trigger output spikes based on an integrate-and-fire mechanism. The spiking neuron circuit can potentially emulate biological neuron networks and their intelligent functions.

  17. A spiking neuron circuit based on a carbon nanotube transistor

    NASA Astrophysics Data System (ADS)

    Chen, C.-L.; Kim, K.; Truong, Q.; Shen, A.; Li, Z.; Chen, Y.

    2012-07-01

    A spiking neuron circuit based on a carbon nanotube (CNT) transistor is presented in this paper. The spiking neuron circuit has a crossbar architecture in which the transistor gates are connected to its row electrodes and the transistor sources are connected to its column electrodes. An electrochemical cell is incorporated in the gate of the transistor by sandwiching a hydrogen-doped poly(ethylene glycol)methyl ether (PEG) electrolyte between the CNT channel and the top gate electrode. An input spike applied to the gate triggers a dynamic drift of the hydrogen ions in the PEG electrolyte, resulting in a post-synaptic current (PSC) through the CNT channel. Spikes input into the rows trigger PSCs through multiple CNT transistors, and PSCs cumulate in the columns and integrate into a ‘soma’ circuit to trigger output spikes based on an integrate-and-fire mechanism. The spiking neuron circuit can potentially emulate biological neuron networks and their intelligent functions.

  18. A spiking neuron circuit based on a carbon nanotube transistor.

    PubMed

    Chen, C-L; Kim, K; Truong, Q; Shen, A; Li, Z; Chen, Y

    2012-07-11

    A spiking neuron circuit based on a carbon nanotube (CNT) transistor is presented in this paper. The spiking neuron circuit has a crossbar architecture in which the transistor gates are connected to its row electrodes and the transistor sources are connected to its column electrodes. An electrochemical cell is incorporated in the gate of the transistor by sandwiching a hydrogen-doped poly(ethylene glycol)methyl ether (PEG) electrolyte between the CNT channel and the top gate electrode. An input spike applied to the gate triggers a dynamic drift of the hydrogen ions in the PEG electrolyte, resulting in a post-synaptic current (PSC) through the CNT channel. Spikes input into the rows trigger PSCs through multiple CNT transistors, and PSCs cumulate in the columns and integrate into a 'soma' circuit to trigger output spikes based on an integrate-and-fire mechanism. The spiking neuron circuit can potentially emulate biological neuron networks and their intelligent functions. PMID:22710137

  19. Rapid Laser Printing of Paper-Based Multilayer Circuits.

    PubMed

    Huang, Gui-Wen; Feng, Qing-Ping; Xiao, Hong-Mei; Li, Na; Fu, Shao-Yun

    2016-09-27

    Laser printing has been widely used in daily life, and the fabricating process is highly efficient and mask-free. Here we propose a laser printing process for the rapid fabrication of paper-based multilayer circuits. It does not require wetting of the paper, which is more competitive in manufacturing paper-based circuits compared to conventional liquid printing process. In the laser printed circuits, silver nanowires (Ag-NWs) are used as conducting material for their excellent electrical and mechanical properties. By repeating the printing process, multilayer three-dimensional (3D) structured circuits can be obtained, which is quite significant for complex circuit applications. In particular, the performance of the printed circuits can be exactly controlled by varying the process parameters including Ag-NW content and laminating temperature, which offers a great opportunity for rapid prototyping of customized products with designed properties. A paper-based high-frequency radio frequency identification (RFID) label with optimized performance is successfully demonstrated. By adjusting the laminating temperature to 180 °C and the top-layer Ag-NW areal density to 0.3 mg cm(-2), the printed RFID antenna can be conjugately matched with the chip, and a big reading range of ∼12.3 cm with about 2.0 cm over that of the commercial etched Al antenna is achieved. This work provides a promising approach for fast and quality-controlled fabrication of multilayer circuits on common paper and may be enlightening for development of paper-based devices. PMID:27607561

  20. Rapid Laser Printing of Paper-Based Multilayer Circuits.

    PubMed

    Huang, Gui-Wen; Feng, Qing-Ping; Xiao, Hong-Mei; Li, Na; Fu, Shao-Yun

    2016-09-27

    Laser printing has been widely used in daily life, and the fabricating process is highly efficient and mask-free. Here we propose a laser printing process for the rapid fabrication of paper-based multilayer circuits. It does not require wetting of the paper, which is more competitive in manufacturing paper-based circuits compared to conventional liquid printing process. In the laser printed circuits, silver nanowires (Ag-NWs) are used as conducting material for their excellent electrical and mechanical properties. By repeating the printing process, multilayer three-dimensional (3D) structured circuits can be obtained, which is quite significant for complex circuit applications. In particular, the performance of the printed circuits can be exactly controlled by varying the process parameters including Ag-NW content and laminating temperature, which offers a great opportunity for rapid prototyping of customized products with designed properties. A paper-based high-frequency radio frequency identification (RFID) label with optimized performance is successfully demonstrated. By adjusting the laminating temperature to 180 °C and the top-layer Ag-NW areal density to 0.3 mg cm(-2), the printed RFID antenna can be conjugately matched with the chip, and a big reading range of ∼12.3 cm with about 2.0 cm over that of the commercial etched Al antenna is achieved. This work provides a promising approach for fast and quality-controlled fabrication of multilayer circuits on common paper and may be enlightening for development of paper-based devices.

  1. Base drive circuit for a four-terminal power Darlington

    DOEpatents

    Lee, Fred C.; Carter, Roy A.

    1983-01-01

    A high power switching circuit which utilizes a four-terminal Darlington transistor block to improve switching speed, particularly in rapid turn-off. Two independent reverse drive currents are utilized during turn off in order to expel the minority carriers of the Darlington pair at their own charge sweep-out rate. The reverse drive current may be provided by a current transformer, the secondary of which is tapped to the base terminal of the power stage of the Darlington block. In one application, the switching circuit is used in each power switching element in a chopper-inverter drive of an electric vehicle propulsion system.

  2. Silica Integrated Optical Circuits Based on Glass Photosensitivity

    NASA Technical Reports Server (NTRS)

    Abushagur, Mustafa A. G.

    1999-01-01

    Integrated optical circuits play a major rule in the new photonics technology both in communication and sensing due to their small size and compatibility with integrated circuits. Currently integrated optical circuits (IOCs) are fabricated using similar manufacturing to those used in the semiconductor industry. In this study we are considering a new technique to fabricate IOCs which does not require layers of photolithography, depositing and etching. This method is based on the photosensitivity of germanosilicate glasses. Waveguides and other IOC devises can be patterned in these glasses by exposing them using UV lasers. This exposure by UV light changes the index of refraction of the germanosilicate glass. This technique enjoys both the simplicity and flexibility of design and fabrication with also the potential of being fast and low cost.

  3. Web-Based Trainer for Electrical Circuit Analysis

    ERIC Educational Resources Information Center

    Weyten, L.; Rombouts, P.; De Maeyer, J.

    2009-01-01

    A Web-based system for training electric circuit analysis is presented in this paper. It is centered on symbolic analysis techniques and it not only verifies the student's final answer, but it also tracks and coaches him/her through all steps of his/her reasoning path. The system mimics homework assignments, enhanced by immediate personalized…

  4. Reprogrammable Logic Gate and Logic Circuit Based on Multistimuli-Responsive Raspberry-like Micromotors.

    PubMed

    Zhang, Lina; Zhang, Hui; Liu, Mei; Dong, Bin

    2016-06-22

    In this paper, we report a polymer-based raspberry-like micromotor. Interestingly, the resulting micromotor exhibits multistimuli-responsive motion behavior. Its on-off-on motion can be regulated by the application of stimuli such as H2O2, near-infrared light, NH3, or their combinations. Because of the versatility in motion control, the current micromotor has great potential in the application field of logic gate and logic circuit. With use of different stimuli as the inputs and the micromotor motion as the output, reprogrammable OR and INHIBIT logic gates or logic circuit consisting of OR, NOT, and AND logic gates can be achieved. PMID:27237969

  5. Friction-based energy dissipation unit for circuit breaker

    SciTech Connect

    Kar, R.; Rainer, J.H.

    1995-12-31

    This paper describes a friction-based energy dissipation unit (EDU) that has been designed to introduce supplemental damping into a circuit breaker. The brittle porcelain insulator posts of a 330 kV SF6 breaker were thus subjected to reduced forces from a design earthquake specified to have a peak ground acceleration of 1.05 g. Pull and release tests were performed to determine the dynamic properties, i.e., natural frequency, damping ratio, and mode shapes. Calculations of response of the circuit breaker to the 1940 El Centro N-S component shows that the EDU reduces the bending moment at the base of the porcelain column by a factor of three.

  6. Different types of synchronization in coupled network based chaotic circuits

    NASA Astrophysics Data System (ADS)

    Srinivasan, K.; Chandrasekar, V. K.; Gladwin Pradeep, R.; Murali, K.; Lakshmanan, M.

    2016-10-01

    We propose a simple and new unified method to achieve lag, complete and anticipatory synchronizations in coupled nonlinear systems. It can be considered as an alternative to the subsystem and intentional parameter mismatch methods. This novel method is illustrated in a unidirectionally coupled RC phase shift network based Chua's circuit. Employing feedback coupling, different types of chaos synchronization are observed experimentally and numerically in coupled identical chaotic oscillators without using time delay. With a simple switch in the experimental set up we observe different kinds of synchronization. We also analyze the coupled system with numerical simulations.

  7. InP-based three-dimensional photonic integrated circuits

    NASA Astrophysics Data System (ADS)

    Tsou, Diana; Zaytsev, Sergey; Pauchard, Alexandre; Hummel, Steve; Lo, Yu-Hwa

    2001-10-01

    Fast-growing internet traffic volumes require high data communication bandwidth over longer distances than short wavelength (850 nm) multi-mode fiber systems can provide. Access network bottlenecks put pressure on short-range (SR) telecommunication systems. To effectively address these datacom and telecom market needs, low cost, high-speed laser modules at 1310 and 1550 nm wavelengths are required. The great success of GaAs 850 nm VCSELs for Gb/s Ethernet has motivated efforts to extend VCSEL technology to longer wavelengths in the 1310 and 1550 nm regimes. However, the technological challenges associated with available intrinsic materials for long wavelength VCSELs are tremendous. Even with recent advances in this area, it is believed that significant additional development is necessary before long wavelength VCSELs that meet commercial specifications will be widely available. In addition, the more stringent OC192 and OC768 specifications for single-mode fiber (SMF) datacom may require more than just a long wavelength laser diode, VCSEL or not, to address numerous cost and performance issues. We believe that photonic integrated circuits, which compactly integrate surface-emitting lasers with additional active and passive optical components with extended functionality, will provide the best solutions to today's problems. Photonic integrated circuits (PICs) have been investigated for more than a decade. However, they have produced limited commercial impact to date primarily because the highly complicated fabrication processes produce significant yield and device performance issues. In this presentation, we will discuss a new technology platform for fabricating InP-based photonic integrated circuits compatible with surface-emitting laser technology. Employing InP transparency at 1310 and 1550 nm wavelengths, we have created 3-D photonic integrated circuits (PICs) by utilizing light beams in both surface normal and in-plane directions within the InP-based structure

  8. Module Seven: Combination Circuits and Voltage Dividers; Basic Electricity and Electronics Individualized Learning System.

    ERIC Educational Resources Information Center

    Bureau of Naval Personnel, Washington, DC.

    In this module the student will learn to apply the rules previously learned for series and parallel circuits to more complex circuits called series-parallel circuits, discover the utility of a common reference when making reference to voltage values, and learn how to obtain a required voltage from a voltage divider network. The module is divided…

  9. A New Simple Chaotic Circuit Based on Memristor

    NASA Astrophysics Data System (ADS)

    Wu, Renping; Wang, Chunhua

    In this paper, a new memristor is proposed, and then an emulator built from off-the-shelf solid state components imitating the behavior of the proposed memristor is presented. Multisim simulation and breadboard experiment are done on the emulator, exhibiting a pinched hysteresis loop in the voltage-current plane when the emulator is driven by a periodic excitation voltage. In addition, a new simple chaotic circuit is designed by using the proposed memristor and other circuit elements. It is exciting that this circuit with only a linear negative resistor, a capacitor, an inductor and a memristor can generate a chaotic attractor. The dynamical behaviors of the proposed chaotic system are analyzed by Lyapunov exponents, phase portraits and bifurcation diagrams. Finally, an electronic circuit is designed to implement the chaotic system. For the sake of simple circuit topology, the proposed chaotic circuit can be easily manufactured at low cost.

  10. Mass sensing based on a circuit cavity electromechanical system

    NASA Astrophysics Data System (ADS)

    Jiang, Cheng; Chen, Bin; Li, Jin-Jin; Zhu, Ka-Di

    2011-10-01

    We present a scheme for mass sensing based on a circuit cavity electromechanical system where a free-standing, flexible aluminium membrane is capacitively coupled to a superconducting microwave cavity. Integration with the microwave cavity enables capacitive readout of the mechanical resonance directly on the chip. A microwave pump field and a second probe field are simultaneously applied to the cavity. The accreted mass landing on the membrane can be measured conveniently by tracking the mechanical resonance frequency shifts due to mass changes in the probe transmission spectrum. The mass responsivity for the membrane is 0.72 Hz/ag and we demonstrate that frequency shifts induced by adsorption of one hundred 1587 bp DNA molecules can be well resolved in the probe transmission spectrum.

  11. A Novel Selection Circuit Based on Rough Comparison Method for Genetic Algorithms Hardware

    NASA Astrophysics Data System (ADS)

    Hiratsuka, Tomokazu; Tamukoh, Hakaru; Horio, Keiichi; Yamakawa, Takeshi

    Genetic algorithms (GAs) are search algorithms based on the mechanics of natural selection and natural evolution. Due to cost reasons, hardware accelerators for GAs are required to reduce its execution time. In the hardware implementation of GAs, a circuit design of roulette wheel selection influences the performance of the GAs hardware. In this paper, we propose a new selection circuit based on Rough Comparison Method (RCM), and evaluate effects of the proposed circuit in terms of execution time and circuit size. The RCM is a parallel processing circuit. Therefore, the execution time is constant regardless of the increase of number in individuals, and the circuit size of the RCM is reduced than the ordinary parallel roulette selection circuits.

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

    PubMed

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

    2014-08-01

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

  13. Recurrence-based detection of the hyperchaos-chaos transition in an electronic circuit

    NASA Astrophysics Data System (ADS)

    Ngamga, E. J.; Buscarino, A.; Frasca, M.; Sciuto, G.; Kurths, J.; Fortuna, L.

    2010-12-01

    Some complex measures based on recurrence plots give evidence about hyperchaos-chaos transitions in coupled nonlinear systems [E. G. Souza et al., "Using recurrences to characterize the hyperchaos-chaos transition," Phys. Rev. E 78, 066206 (2008)]. In this paper, these measures are combined with a significance test based on twin surrogates to identify such a transition in a fourth-order Lorenz-like system, which is able to pass from a hyperchaotic to a chaotic behavior for increasing values of a single parameter. A circuit analog of the mathematical model has been designed and implemented and the robustness of the recurrence-based method on experimental data has been tested. In both the numerical and experimental cases, the combination of the recurrence measures and the significance test allows to clearly identify the hyperchaos-chaos transition.

  14. Coupled circuit based representation of piezoelectric structures modeled using the finite volume method.

    PubMed

    Bolborici, V; Dawson, F P

    2016-03-01

    This paper presents the methodology of generating a corresponding electrical circuit for a simple piezoelectric plate modeled with the finite volume method. The corresponding circuit is implemented using a circuit simulation software and the simulation results are compared to the finite volume modeling results for validation. It is noticed that both, the finite volume model and its corresponding circuit, generate identical results. The results of a corresponding circuit based on the finite volume model are also compared to the results of a corresponding circuit based on a simplified analytical model for a long piezoelectric plate, and to finite element simulation results for the same plate. It is observed that, for one control volume, the finite volume model corresponding circuit and the simplified analytical model corresponding circuit generate close results. It is also noticed that the results of the two corresponding circuits are different from the best approximation results obtained with high resolution finite element simulations due to the approximations made in the simplified analytical model and the fact that only one finite volume was used in the finite volume model. The implementation of the circuit can be automated for higher order systems by a program that takes as an input the matrix of the system and the forcing function vector, and returns a net list for the circuit.

  15. An novel frequent probability pattern mining algorithm based on circuit simulation method in uncertain biological networks

    PubMed Central

    2014-01-01

    Background Motif mining has always been a hot research topic in bioinformatics. Most of current research on biological networks focuses on exact motif mining. However, due to the inevitable experimental error and noisy data, biological network data represented as the probability model could better reflect the authenticity and biological significance, therefore, it is more biological meaningful to discover probability motif in uncertain biological networks. One of the key steps in probability motif mining is frequent pattern discovery which is usually based on the possible world model having a relatively high computational complexity. Methods In this paper, we present a novel method for detecting frequent probability patterns based on circuit simulation in the uncertain biological networks. First, the partition based efficient search is applied to the non-tree like subgraph mining where the probability of occurrence in random networks is small. Then, an algorithm of probability isomorphic based on circuit simulation is proposed. The probability isomorphic combines the analysis of circuit topology structure with related physical properties of voltage in order to evaluate the probability isomorphism between probability subgraphs. The circuit simulation based probability isomorphic can avoid using traditional possible world model. Finally, based on the algorithm of probability subgraph isomorphism, two-step hierarchical clustering method is used to cluster subgraphs, and discover frequent probability patterns from the clusters. Results The experiment results on data sets of the Protein-Protein Interaction (PPI) networks and the transcriptional regulatory networks of E. coli and S. cerevisiae show that the proposed method can efficiently discover the frequent probability subgraphs. The discovered subgraphs in our study contain all probability motifs reported in the experiments published in other related papers. Conclusions The algorithm of probability graph isomorphism

  16. Variable Time Base Integrator Circuit for Buffet Signal Measurements

    NASA Technical Reports Server (NTRS)

    Batts, Colossie N.

    1973-01-01

    A measurement circuit to obtain buffet data from wind tunnel models wherein a signal proportional to the average RMS value of buffet data is produced for subsequent recording. Feedback means are employed to suppress the D.C. portion of signals developed by the strain gages during dynamic testing. Automatic recording of gain settings of amplifiers employed in the circuit is also provided.

  17. Comparing and Combining Real and Virtual Experimentation: An Effort to Enhance Students' Conceptual Understanding of Electric Circuits

    ERIC Educational Resources Information Center

    Zacharia, Z. C.

    2007-01-01

    The purpose of this study was to investigate value of combining Real Experimentation (RE) with Virtual Experimentation (VE) with respect to changes in students' conceptual understanding of electric circuits. To achieve this, a pre-post comparison study design was used that involved 88 undergraduate students. The participants were randomly assigned…

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

    Here a facile, green and efficient printing-filtration-press (PFP) technique is reported for room-temperature (RT) mass-production of low-cost, environmentally friendly, high performance paper-based electronic circuits. The as-prepared silver nanowires (Ag-NWs) are uniformly deposited at RT on a pre-printed paper substrate to form high quality circuits via vacuum filtration and pressing. The PFP circuit exhibits more excellent electrical property and bending stability compared with other flexible circuits made by existing techniques. Furthermore, practical applications of the PFP circuits are demonstrated.Here a facile, green and efficient printing-filtration-press (PFP) technique is reported for room-temperature (RT) mass-production of low-cost, environmentally friendly, high performance paper-based electronic circuits. The as-prepared silver nanowires (Ag-NWs) are uniformly deposited at RT on a pre-printed paper substrate to form high quality circuits via vacuum filtration and pressing. The PFP circuit exhibits more excellent electrical property and bending stability compared with other flexible circuits made by existing techniques. Furthermore, practical applications of the PFP circuits are demonstrated. Electronic supplementary information (ESI) available: Video of rolling tests; video of the PFP circuit used as flexible cable in a cell phone; video of the application of the circuit as a RFID tag; a detailed method for synthesizing silver nanowires; details of the PFP technique; folding tests for the circuits; air humidity test for the circuit. See DOI: 10.1039/c4nr00846d

  19. PC-based closed-circuit television system

    NASA Astrophysics Data System (ADS)

    Christoffersen, Daniel; Clark, Carl

    The PC-based closed-circuit television (CCTV) system is a low-cost, highly functional alternative to conventional video system equipment. The system provides routing switching, character generation, video presence detection, and solid-state video recording and replay by using four uniquely designed boards that fit into the backplane slots of an IBM PC-XT-compatible personal computer. Each board controls 16 separate channels, and the boards can be daisy-chained together to build larger, more powerful systems. The system can be configured to handle as many as 240 input signals or up to 48 output channels, and uses a redundant video bus loop. The video bus can be tapped into throughout the loop to provide localized routing switching within several buildings, and video termination at multiple locations, such as security operators' stations. This approach reduces cabling costs and allows additional routing switchers to be added easily with little impact on existing equipment. The system is capable of communicating with several control interfaces, and control software is currently in place for communicating via an RS-232 link and the Intel BitBus network. The hardware drivers are Microsoft C modules that can be linked with a user developed control program.

  20. Mixed application MMIC technologies - Progress in combining RF, digital and photonic circuits

    NASA Technical Reports Server (NTRS)

    Swirhun, S.; Bendett, M.; Sokolov, V.; Bauhahn, P.; Sullivan, C.; Mactaggart, R.; Mukherjee, S.; Hibbs-Brenner, M.; Mondal, J.

    1991-01-01

    Approaches for future 'mixed application' monolithic integrated circuits (ICs) employing optical receive/transmit, RF amplification and modulation and digital control functions are discussed. We focus on compatibility of the photonic component fabrication with conventional RF and digital IC technologies. Recent progress at Honeywell in integrating several parts of the desired RF/digital/photonic circuit integration suite required for construction of a future millimeter-wave optically-controlled phased-array element are illustrated.

  1. A Step Response Based Mixed-Signal BIST Approach for Continuous-time Linear Circuits

    NASA Technical Reports Server (NTRS)

    Walker, Alvernon; Lala, P. K.

    2001-01-01

    A new Mixed-Signal Built-in self-test approach that is based upon the step response of a reconfigurable (or multifunction) analog block is presented in this paper. The technique requires the overlapping step response of the Circuit Under Test (CUT) for two circuit configurations. Each configuration can be realized by changing the topology of the CUT or by sampling two CUT nodes with differing step responses. The technique can effectively detect both soft and hard faults and does not require an analog-to-digital converter (ADC) and/or digital-to-analog converter(DAC). It also does not require any precision voltage sources or comparators. This approach does not require any additional analog circuits to realize the test signal generator and sample circuits. The paper is concluded with the application of the proposed approach to a circuit found in the work of Epstein et al and two ITC 97 analog benchmark circuits.

  2. A novel circuit design for complementary resistive switch-based stateful logic operations

    NASA Astrophysics Data System (ADS)

    Xiao-Ping, Wang; Lin, Chen; Yi, Shen; Bo-Wen, Xu

    2016-05-01

    Recently, it has been demonstrated that memristors can be utilized as logic operations and memory elements. In this paper, we present a novel circuit design for complementary resistive switch (CRS)-based stateful logic operations. The proposed circuit can automatically write the destructive CRS cells back to the original states. In addition, the circuit can be used in massive passive crossbar arrays which can reduce sneak path current greatly. Moreover, the steps for CRS logic operations using our proposed circuit are reduced compared with previous circuit designs. We validate the effectiveness of our scheme through Hspice simulations on the logic circuits. Project supported by the National Natural Science Foundation of China (Grant Nos. 61374150 and 11271146), the State Key Program of the National Natural Science Foundation of China (Grant No. 61134012), the Doctoral Fund of Ministry of Education of China (Grant No. 20130142130012), and the Science and Technology Program of Shenzhen City, China (Grant No. JCYJ20140509162710496).

  3. Circuit theory and model-based inference for landscape connectivity

    USGS Publications Warehouse

    Hanks, Ephraim M.; Hooten, Mevin B.

    2013-01-01

    Circuit theory has seen extensive recent use in the field of ecology, where it is often applied to study functional connectivity. The landscape is typically represented by a network of nodes and resistors, with the resistance between nodes a function of landscape characteristics. The effective distance between two locations on a landscape is represented by the resistance distance between the nodes in the network. Circuit theory has been applied to many other scientific fields for exploratory analyses, but parametric models for circuits are not common in the scientific literature. To model circuits explicitly, we demonstrate a link between Gaussian Markov random fields and contemporary circuit theory using a covariance structure that induces the necessary resistance distance. This provides a parametric model for second-order observations from such a system. In the landscape ecology setting, the proposed model provides a simple framework where inference can be obtained for effects that landscape features have on functional connectivity. We illustrate the approach through a landscape genetics study linking gene flow in alpine chamois (Rupicapra rupicapra) to the underlying landscape.

  4. Printed circuits. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Reed, W. E.

    1980-04-01

    The design, fabrication, testing, and applications of printed circuits are presented in these citations of Federally-sponsored research reports. Research on computer aided design, soldering, etching, plating, photolithography, and materials are cited. This updated bibliography contains 175 abstracts, 41 of which are new entries to the previous edition.

  5. Plasmonic-multimode-interference-based logic circuit with simple phase adjustment

    PubMed Central

    Ota, Masashi; Sumimura, Asahi; Fukuhara, Masashi; Ishii, Yuya; Fukuda, Mitsuo

    2016-01-01

    All-optical logic circuits using surface plasmon polaritons have a potential for high-speed information processing with high-density integration beyond the diffraction limit of propagating light. However, a number of logic gates that can be cascaded is limited by complicated signal phase adjustment. In this study, we demonstrate a half-adder operation with simple phase adjustment using plasmonic multimode interference (MMI) devices, composed of dielectric stripes on a metal film, which can be fabricated by a complementary metal-oxide semiconductor (MOS)-compatible process. Also, simultaneous operations of XOR and AND gates are substantiated experimentally by combining 1 × 1 MMI based phase adjusters and 2 × 2 MMI based intensity modulators. An experimental on-off ratio of at least 4.3 dB is confirmed using scanning near-field optical microscopy. The proposed structure will contribute to high-density plasmonic circuits, fabricated by complementary MOS-compatible process or printing techniques. PMID:27086694

  6. Plasmonic-multimode-interference-based logic circuit with simple phase adjustment

    NASA Astrophysics Data System (ADS)

    Ota, Masashi; Sumimura, Asahi; Fukuhara, Masashi; Ishii, Yuya; Fukuda, Mitsuo

    2016-04-01

    All-optical logic circuits using surface plasmon polaritons have a potential for high-speed information processing with high-density integration beyond the diffraction limit of propagating light. However, a number of logic gates that can be cascaded is limited by complicated signal phase adjustment. In this study, we demonstrate a half-adder operation with simple phase adjustment using plasmonic multimode interference (MMI) devices, composed of dielectric stripes on a metal film, which can be fabricated by a complementary metal-oxide semiconductor (MOS)-compatible process. Also, simultaneous operations of XOR and AND gates are substantiated experimentally by combining 1 × 1 MMI based phase adjusters and 2 × 2 MMI based intensity modulators. An experimental on-off ratio of at least 4.3 dB is confirmed using scanning near-field optical microscopy. The proposed structure will contribute to high-density plasmonic circuits, fabricated by complementary MOS-compatible process or printing techniques.

  7. [Modeling and analysis of volume conduction based on field-circuit coupling].

    PubMed

    Tang, Zhide; Liu, Hailong; Xie, Xiaohui; Chen, Xiufa; Hou, Deming

    2012-08-01

    Numerical simulations of volume conduction can be used to analyze the process of energy transfer and explore the effects of some physical factors on energy transfer efficiency. We analyzed the 3D quasi-static electric field by the finite element method, and developed A 3D coupled field-circuit model of volume conduction basing on the coupling between the circuit and the electric field. The model includes a circuit simulation of the volume conduction to provide direct theoretical guidance for energy transfer optimization design. A field-circuit coupling model with circular cylinder electrodes was established on the platform of the software FEM3.5. Based on this, the effects of electrode cross section area, electrode distance and circuit parameters on the performance of volume conduction system were obtained, which provided a basis for optimized design of energy transfer efficiency.

  8. FDSAC-SPICE: fault diagnosis software for analog circuit based on SPICE simulation

    NASA Astrophysics Data System (ADS)

    Cao, Yiqin; Cen, Zhao-Hui; Wei, Jiao-Long

    2009-12-01

    This paper presents a novel fault diagnosis software (called FDSAC-SPICE) based on SPICE simulator for analog circuits. Four important techniques in AFDS-SPICE, including visual user-interface(VUI), component modeling and fault modeling (CMFM), fault injection and fault simulation (FIFS), fault dictionary and fault diagnosis (FDFD), greatly increase design-for-test and diagnosis efficiency of analog circuit by building a fault modeling-injection-simulationdiagnosis environment to get prior fault knowledge of target circuit. AFDS-SPICE also generates accurate fault coverage statistics that are tied to the circuit specifications. With employing a dictionary diagnosis method based on node-signalcharacters and regular BPNN algorithm, more accurate and effective diagnosis results are available for analog circuit with tolerance.

  9. Derandomizing Quantum Circuits with Measurement-Based Unitary Designs

    NASA Astrophysics Data System (ADS)

    Turner, Peter S.; Markham, Damian

    2016-05-01

    Entangled multipartite states are resources for universal quantum computation, but they can also give rise to ensembles of unitary transformations, a topic usually studied in the context of random quantum circuits. Using several graph state techniques, we show that these resources can "derandomize" circuit results by sampling the same kinds of ensembles quantum mechanically, analogously to a quantum random number generator. Furthermore, we find simple examples that give rise to new ensembles whose statistical moments exactly match those of the uniformly random distribution over all unitaries up to order t , while foregoing adaptive feedforward entirely. Such ensembles—known as t designs—often cannot be distinguished from the "truly" random ensemble, and so they find use in many applications that require this implied notion of pseudorandomness.

  10. Derandomizing Quantum Circuits with Measurement-Based Unitary Designs.

    PubMed

    Turner, Peter S; Markham, Damian

    2016-05-20

    Entangled multipartite states are resources for universal quantum computation, but they can also give rise to ensembles of unitary transformations, a topic usually studied in the context of random quantum circuits. Using several graph state techniques, we show that these resources can "derandomize" circuit results by sampling the same kinds of ensembles quantum mechanically, analogously to a quantum random number generator. Furthermore, we find simple examples that give rise to new ensembles whose statistical moments exactly match those of the uniformly random distribution over all unitaries up to order t, while foregoing adaptive feedforward entirely. Such ensembles-known as t designs-often cannot be distinguished from the "truly" random ensemble, and so they find use in many applications that require this implied notion of pseudorandomness. PMID:27258858

  11. Derandomizing Quantum Circuits with Measurement-Based Unitary Designs.

    PubMed

    Turner, Peter S; Markham, Damian

    2016-05-20

    Entangled multipartite states are resources for universal quantum computation, but they can also give rise to ensembles of unitary transformations, a topic usually studied in the context of random quantum circuits. Using several graph state techniques, we show that these resources can "derandomize" circuit results by sampling the same kinds of ensembles quantum mechanically, analogously to a quantum random number generator. Furthermore, we find simple examples that give rise to new ensembles whose statistical moments exactly match those of the uniformly random distribution over all unitaries up to order t, while foregoing adaptive feedforward entirely. Such ensembles-known as t designs-often cannot be distinguished from the "truly" random ensemble, and so they find use in many applications that require this implied notion of pseudorandomness.

  12. CMOS Interface Circuits for Spin Tunneling Junction Based Magnetic Random Access Memories

    SciTech Connect

    Ganesh Saripalli

    2002-12-31

    Magneto resistive memories (MRAM) are non-volatile memories which use magnetic instead of electrical structures to store data. These memories, apart from being non-volatile, offer a possibility to achieve densities better than DRAMs and speeds faster than SRAMs. MRAMs could potentially replace all computer memory RAM technologies in use today, leading to future applications like instan-on computers and longer battery life for pervasive devices. Such rapid development was made possible due to the recent discovery of large magnetoresistance in Spin tunneling junction devices. Spin tunneling junctions (STJ) are composite structures consisting of a thin insulating layer sandwiched between two magnetic layers. This thesis research is targeted towards these spin tunneling junction based Magnetic memories. In any memory, some kind of an interface circuit is needed to read the logic states. In this thesis, four such circuits are proposed and designed for Magnetic memories (MRAM). These circuits interface to the Spin tunneling junctions and act as sense amplifiers to read their magnetic states. The physical structure and functional characteristics of these circuits are discussed in this thesis. Mismatch effects on the circuits and proper design techniques are also presented. To demonstrate the functionality of these interface structures, test circuits were designed and fabricated in TSMC 0.35{micro} CMOS process. Also circuits to characterize the process mismatches were fabricated and tested. These results were then used in Matlab programs to aid in design process and to predict interface circuit's yields.

  13. A novel prediction method about single components of analog circuits based on complex field modeling.

    PubMed

    Zhou, Jingyu; Tian, Shulin; Yang, Chenglin

    2014-01-01

    Few researches pay attention to prediction about analog circuits. The few methods lack the correlation with circuit analysis during extracting and calculating features so that FI (fault indicator) calculation often lack rationality, thus affecting prognostic performance. To solve the above problem, this paper proposes a novel prediction method about single components of analog circuits based on complex field modeling. Aiming at the feature that faults of single components hold the largest number in analog circuits, the method starts with circuit structure, analyzes transfer function of circuits, and implements complex field modeling. Then, by an established parameter scanning model related to complex field, it analyzes the relationship between parameter variation and degeneration of single components in the model in order to obtain a more reasonable FI feature set via calculation. According to the obtained FI feature set, it establishes a novel model about degeneration trend of analog circuits' single components. At last, it uses particle filter (PF) to update parameters for the model and predicts remaining useful performance (RUP) of analog circuits' single components. Since calculation about the FI feature set is more reasonable, accuracy of prediction is improved to some extent. Finally, the foregoing conclusions are verified by experiments. PMID:25147853

  14. An application specific integrated circuit based multi-anode microchannel array readout system

    NASA Technical Reports Server (NTRS)

    Smeins, Larry G.; Stechman, John M.; Cole, Edward H.

    1991-01-01

    Size reduction of two new multi-anode microchannel array (MAMA) readout systems is described. The systems are based on two analog and one digital application specific integrated circuits (ASICs). The new readout systems reduce volume over previous discrete designs by 80 percent while improving electrical performance on virtually every significant parameter. Emphasis is made on the packaging used to achieve the volume reduction. Surface mount technology (SMT) is combined with modular construction for the analog portion of the readout. SMT reliability concerns and the board area impact of MIL SPEC SMT components is addressed. Package selection for the analog ASIC is discussed. Future sytems will require even denser packaging and the volume reduction progression is shown.

  15. Optically controllable molecular logic circuits

    SciTech Connect

    Nishimura, Takahiro Fujii, Ryo; Ogura, Yusuke; Tanida, Jun

    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.

  16. Combined Aircraft and Satellite-Derived Storm Electric Current and Lightning Rates Measurements and Implications for the Global Electric Circuit

    NASA Technical Reports Server (NTRS)

    Mach, Douglas M.; Blakeslee, Richard J.; Bateman, Monte G.

    2010-01-01

    Using rotating vane electric field mills and Gerdien capacitors, we measured the electric field profile and conductivity during 850 overflights of electrified shower clouds and thunderstorms spanning regions including the Southeastern United States, the Western Atlantic Ocean, the Gulf of Mexico, Central America and adjacent oceans, Central Brazil, and the South Pacific. The overflights include storms over land and ocean, with and without lightning, and with positive and negative fields above the storms. The measurements were made with the NASA ER-2 and the Altus-II high altitude aircrafts. Peak electric fields, with lightning transients removed, ranged from -1.0 kV/m to 16 kV/m, with a mean value of 0.9 kV/m. The median peak field was 0.29 kV/m. Integrating our electric field and conductivity data, we determined total conduction currents and flash rates for each overpass. With knowledge of the storm location (land or ocean) and type (with or without lightning), we determine the mean currents by location and type. The mean current for ocean storms with lightning is 1.6 A while the mean current for land storms with lightning is 1.0 A. The mean current for oceanic storms without lightning (i.e., electrified shower clouds) is 0.39 A and the mean current for land storms without lightning is 0.13 A. Thus, on average, land storms with or without lightning have about half the mean current as their corresponding oceanic storm counterparts. Over three-quarters (78%) of the land storms had detectable lightning, while less than half (43%) of the oceanic storms had lightning. We did not find any significant regional or latitudinal based patterns in our total conduction currents. By combining the aircraft derived storm currents and flash rates with diurnal lightning statistics derived from the Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) low Earth orbiting satellites, we reproduce the diurnal variation in the global electric circuit (i.e., the Carnegie

  17. Powerful Amplification Cascades of FRET-Based Two-Layer Nonenzymatic Nucleic Acid Circuits.

    PubMed

    Quan, Ke; Huang, Jin; Yang, Xiaohai; Yang, Yanjing; Ying, Le; Wang, He; Xie, Nuli; Ou, Min; Wang, Kemin

    2016-06-01

    Nucleic acid circuits have played important roles in biological engineering and have increasingly attracted researchers' attention. They are primarily based on nucleic acid hybridizations and strand displacement reactions between nucleic acid probes of different lengths. Signal amplification schemes that do not rely on protein enzyme show great potential in analytical applications. While the single amplification circuit often achieves linear amplification that may not meet the need for detection of target in a very small amount, it is very necessary to construct cascade circuits that allow for larger amplification of inputs. Herein, we have successfully engineered powerful amplification cascades of FRET-based two-layer nonenzymatic nucleic acid circuits, in which the outputs of catalyzed hairpin assembly (CHA) activate hybridization chain reactions (HCR) circuits to induce repeated hybridization, allowing real-time monitoring of self-assembly process by FRET signal. The cascades can yield 50000-fold signal amplification with the help of the well-designed and high-quality nucleic acid circuit amplifiers. Subsequently, with coupling of structure-switching aptamer, as low as 200 pM adenosine is detected in buffer, as well as in human serum. To our knowledge, we have for the first time realized real-time monitoring adaptation of HCR to CHA circuits and achieved amplified detection of nucleic acids and small molecules with relatively high sensitivity. PMID:27142084

  18. Mixed Electromagnetic and Circuit Simulations using Higher-Order Elements and Bases

    SciTech Connect

    Champagne, N J; Rockway, J D; Jandhyala, V

    2003-06-18

    In this paper, an approach to couple higher-order electromagnetic surface integral equations to circuit simulations is presented. Terminals are defined that connect circuit elements to contacts modeled on the distributed electromagnetic domain. A modified charge-current continuity equation is proposed for a generalized KCL connection at the contacts. The distributive electromagnetic integral equations are developed using higher-order bases and elements that allow both better convergence and accuracy for modeling. The resulting scheme enables simultaneous solution of electromagnetic integral equations for arbitrarily-shaped objects and SPICE-like modeling for lumped circuits, and permits design iterations and visualization of the interaction between the two domains.

  19. Fundamental electric circuit elements based on the linear and nonlinear magnetoelectric effects (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Sun, Young; Shang, Dashan; Chai, Yisheng; Cao, Zexian; Lu, Jun

    2015-09-01

    From the viewpoint of electric circuit theory, the three fundamental two-terminal passive circuit elements, resistor R , capacitor C, and inductor L, are defined in terms of a relationship between two of the four basic circuit variables, charge q, current i, voltage v, and magnetic flux φ. From a symmetry concern, there should be a fourth fundamental element defined from the relationship between charge q and magnetic flux φ. Here we present both theoretical analysis and experimental evidences to demonstrate that a two-terminal passive device employing the magnetoelectric (ME) effects can exhibit a direct relationship between charge q and magnetic flux φ, and thus is able to act as the fourth fundamental circuit element. The ME effects refer to the induction of electric polarization by a magnetic field or magnetization by an electric field, and have attracted enormous interests due to their promise in many applications. However, no one has linked the ME effects with fundamental circuit theory. Both the linear and nonlinear-memory devices, termed transtor and memtranstor, respectively, have been experimentally realized using multiferroic materials showing strong ME effects. Based on our work, a full map of fundamental two-terminal circuit elements is constructed, which consists of four linear and four nonlinear-memory elements. This full map provides an invaluable guide to developing novel circuit functionalities in the future.

  20. Corticostriatal circuit mechanisms of value-based action selection: Implementation of reinforcement learning algorithms and beyond.

    PubMed

    Morita, Kenji; Jitsev, Jenia; Morrison, Abigail

    2016-09-15

    Value-based action selection has been suggested to be realized in the corticostriatal local circuits through competition among neural populations. In this article, we review theoretical and experimental studies that have constructed and verified this notion, and provide new perspectives on how the local-circuit selection mechanisms implement reinforcement learning (RL) algorithms and computations beyond them. The striatal neurons are mostly inhibitory, and lateral inhibition among them has been classically proposed to realize "Winner-Take-All (WTA)" selection of the maximum-valued action (i.e., 'max' operation). Although this view has been challenged by the revealed weakness, sparseness, and asymmetry of lateral inhibition, which suggest more complex dynamics, WTA-like competition could still occur on short time scales. Unlike the striatal circuit, the cortical circuit contains recurrent excitation, which may enable retention or temporal integration of information and probabilistic "soft-max" selection. The striatal "max" circuit and the cortical "soft-max" circuit might co-implement an RL algorithm called Q-learning; the cortical circuit might also similarly serve for other algorithms such as SARSA. In these implementations, the cortical circuit presumably sustains activity representing the executed action, which negatively impacts dopamine neurons so that they can calculate reward-prediction-error. Regarding the suggested more complex dynamics of striatal, as well as cortical, circuits on long time scales, which could be viewed as a sequence of short WTA fragments, computational roles remain open: such a sequence might represent (1) sequential state-action-state transitions, constituting replay or simulation of the internal model, (2) a single state/action by the whole trajectory, or (3) probabilistic sampling of state/action.

  1. A Behavior-Based Circuit Model of How Outcome Expectations Organize Learned Behavior in Larval "Drosophila"

    ERIC Educational Resources Information Center

    Schleyer, Michael; Saumweber, Timo; Nahrendorf, Wiebke; Fischer, Benjamin; von Alpen, Desiree; Pauls, Dennis; Thum, Andreas; Gerber, Bertram

    2011-01-01

    Drosophila larvae combine a numerically simple brain, a correspondingly moderate behavioral complexity, and the availability of a rich toolbox for transgenic manipulation. This makes them attractive as a study case when trying to achieve a circuit-level understanding of behavior organization. From a series of behavioral experiments, we suggest a…

  2. SOI-Based High-Voltage, High-Temperature Integrated Circuit Gate Driver for SiC-Based Power FETs

    SciTech Connect

    Huque, Mohammad A; Tolbert, Leon M; Blalock, Benjamin; Islam, Syed K

    2010-01-01

    Silicon carbide (SiC)-based field effect transistors (FETs) are gaining popularity as switching elements in power electronic circuits designed for high-temperature environments like hybrid electric vehicle, aircraft, well logging, geothermal power generation etc. Like any other power switches, SiC-based power devices also need gate driver circuits to interface them with the logic units. The placement of the gate driver circuit next to the power switch is optimal for minimizing system complexity. Successful operation of the gate driver circuit in a harsh environment, especially with minimal or no heat sink and without liquid cooling, can increase the power-to-volume ratio as well as the power-to-weight ratio for power conversion modules such as a DC-DC converter, inverter etc. A silicon-on-insulator (SOI)-based high-voltage, high-temperature integrated circuit (IC) gate driver for SiC power FETs has been designed and fabricated using a commercially available 0.8-m, 2-poly and 3-metal bipolar-complementary metal oxide semiconductor (CMOS)-double diffused metal oxide semiconductor (DMOS) process. The prototype circuit-s maximum gate drive supply can be 40-V with peak 2.3-A sourcing/sinking current driving capability. Owing to the wide driving range, this gate driver IC can be used to drive a wide variety of SiC FET switches (both normally OFF metal oxide semiconductor field effect transistor (MOSFET) and normally ON junction field effect transistor (JFET)). The switching frequency is 20-kHz and the duty cycle can be varied from 0 to 100-. The circuit has been successfully tested with SiC power MOSFETs and JFETs without any heat sink and cooling mechanism. During these tests, SiC switches were kept at room temperature and ambient temperature of the driver circuit was increased to 200-C. The circuit underwent numerous temperature cycles with negligible performance degradation.

  3. Sensor readout detector circuit

    DOEpatents

    Chu, D.D.; Thelen, D.C. Jr.

    1998-08-11

    A sensor readout detector circuit is disclosed that is capable of detecting sensor signals down to a few nanoamperes or less in a high (microampere) background noise level. The circuit operates at a very low standby power level and is triggerable by a sensor event signal that is above a predetermined threshold level. A plurality of sensor readout detector circuits can be formed on a substrate as an integrated circuit (IC). These circuits can operate to process data from an array of sensors in parallel, with only data from active sensors being processed for digitization and analysis. This allows the IC to operate at a low power level with a high data throughput for the active sensors. The circuit may be used with many different types of sensors, including photodetectors, capacitance sensors, chemically-sensitive sensors or combinations thereof to provide a capability for recording transient events or for recording data for a predetermined period of time following an event trigger. The sensor readout detector circuit has applications for portable or satellite-based sensor systems. 6 figs.

  4. Sensor readout detector circuit

    DOEpatents

    Chu, Dahlon D.; Thelen, Jr., Donald C.

    1998-01-01

    A sensor readout detector circuit is disclosed that is capable of detecting sensor signals down to a few nanoamperes or less in a high (microampere) background noise level. The circuit operates at a very low standby power level and is triggerable by a sensor event signal that is above a predetermined threshold level. A plurality of sensor readout detector circuits can be formed on a substrate as an integrated circuit (IC). These circuits can operate to process data from an array of sensors in parallel, with only data from active sensors being processed for digitization and analysis. This allows the IC to operate at a low power level with a high data throughput for the active sensors. The circuit may be used with many different types of sensors, including photodetectors, capacitance sensors, chemically-sensitive sensors or combinations thereof to provide a capability for recording transient events or for recording data for a predetermined period of time following an event trigger. The sensor readout detector circuit has applications for portable or satellite-based sensor systems.

  5. Enhancement of galloping-based wind energy harvesting by synchronized switching interface circuits

    NASA Astrophysics Data System (ADS)

    Zhao, Liya; Liang, Junrui; Tang, Lihua; Yang, Yaowen; Liu, Haili

    2015-04-01

    Galloping phenomenon has attracted extensive research attention for small-scale wind energy harvesting. In the reported literature, the dynamics and harvested power of a galloping-based energy harvesting system are usually evaluated with a resistive AC load; these characteristics might shift when a practical harvesting interface circuit is connected for extracting useful DC power. In the family of piezoelectric energy harvesting interface circuits, synchronized switching harvesting on inductor (SSHI) has demonstrated its advantage for enhancing the harvested power from existing base vibrations. This paper investigates the harvesting capability of a galloping-based wind energy harvester using SSHI interfaces, with a focus on comparing the performances of Series SSHI (S-SSHI) and Parallel SSHI (P-SSHI) with that of a standard DC interface, in terms of power at various wind speeds. The prototyped galloping-based piezoelectric energy harvester (GPEH) comprises a piezoelectric cantilever attached with a square-sectioned bluff body made of foam. Equivalent circuit model (ECM) of the GPEH is established and system-level circuit simulations with SSHI and standard interfaces are performed and validated with wind tunnel tests. The benefits of SSHI compared to standard circuit become more significant when the wind speed gets higher; while SSHI circuits lose the benefits at small wind speeds. In both experiment and simulation, the superiority of P-SSHI is confirmed while S-SSHI demands further investigation. The power output is increased by 43.75% with P-SSHI compared to the standard circuit at a wind speed of 6m/s.

  6. Surface-Charge-Based Micro-Models--A Solid Foundation for Learning about Direct Current Circuits

    ERIC Educational Resources Information Center

    Hirvonen, P. E.

    2007-01-01

    This study explores how the use of a surface-charge-based instructional approach affects introductory university level students' understanding of direct current (dc) circuits. The introduced teaching intervention includes electrostatics, surface-charge-based micro-models that explain the existence of an electric field inside the current-carrying…

  7. A Multiple-Sessions Interactive Computer-Based Learning Tool for Ability Cultivation in Circuit Simulation

    ERIC Educational Resources Information Center

    Xu, Q.; Lai, L. L.; Tse, N. C. F.; Ichiyanagi, K.

    2011-01-01

    An interactive computer-based learning tool with multiple sessions is proposed in this paper, which teaches students to think and helps them recognize the merits and limitations of simulation tools so as to improve their practical abilities in electrical circuit simulation based on the case of a power converter with progressive problems. The…

  8. Encountering the Expertise Reversal Effect with a Computer-Based Environment on Electrical Circuit Analysis

    ERIC Educational Resources Information Center

    Reisslein, Jana; Atkinson, Robert K.; Seeling, Patrick; Reisslein, Martin

    2006-01-01

    This study examined the effectiveness of a computer-based environment employing three example-based instructional procedures (example-problem, problem-example, and fading) to teach series and parallel electrical circuit analysis to learners classified by two levels of prior knowledge (low and high). Although no differences between the…

  9. SEMICONDUCTOR DEVICES Intrinsic stability of an HBT based on a small signal equivalent circuit model

    NASA Astrophysics Data System (ADS)

    Yanhu, Chen; Huajun, Shen; Xinyu, Liu; Huijun, Li; Hui, Xu; Ling, Li

    2010-12-01

    Intrinsic stability of the heterojunction bipolar transistor (HBT) was analyzed and discussed based on a small signal equivalent circuit model. The stability factor of the HBT device was derived based on a compact T-type small signal equivalent circuit model of the HBT. The effect of the mainly small signal model parameters of the HBT on the stability of the HBT was thoroughly examined. The discipline of parameter optimum to improve the intrinsic stability of the HBT was achieved. The theoretic analysis results of the stability were also used to explain the experimental results of the stability of the HBT and they were verified by the experimental results.

  10. Towards practical application of paper based printed circuits: capillarity effectively enhances conductivity of the thermoplastic electrically conductive adhesives.

    PubMed

    Wu, Haoyi; Chiang, Sum Wai; Lin, Wei; Yang, Cheng; Li, Zhuo; Liu, Jingping; Cui, Xiaoya; Kang, Feiyu; Wong, Ching Ping

    2014-09-03

    Direct printing nanoparticle-based conductive inks onto paper substrates has encountered difficulties e.g. the nanoparticles are prone to penetrate into the pores of the paper and become partially segmented, and the necessary low-temperature-sintering process is harmful to the dimension-stability of paper. Here we prototyped the paper-based circuit substrate in combination with printed thermoplastic electrically conductive adhesives (ECA), which takes the advantage of the capillarity of paper and thus both the conductivity and mechanical robustness of the printed circuits were drastically improved without sintering process. For instance, the electrical resistivity of the ECA specimen on a pulp paper (6 × 10(-5)Ω · cm, with 50 wt% loading of Ag) was only 14% of that on PET film than that on PET film. This improvement has been found directly related to the sizing degree of paper, in agreement with the effective medium approximation simulation results in this work. The thermoplastic nature also enables excellent mechanical strength of the printed ECA to resist repeated folding. Considering the generality of the process and the wide acceptance of ECA technique in the modern electronic packages, this method may find vast applications in e.g. circuit boards, capacitive touch pads, and radio frequency identification antennas, which have been prototyped in the manuscript.

  11. Multi-octave spectral beam combiner on ultra-broadband photonic integrated circuit platform.

    PubMed

    Stanton, Eric J; Heck, Martijn J R; Bovington, Jock; Spott, Alexander; Bowers, John E

    2015-05-01

    We present the design of a novel platform that is able to combine optical frequency bands spanning 4.2 octaves from ultraviolet to mid-wave infrared into a single, low M2 output waveguide. We present the design and realization of a key component in this platform that combines the wavelength bands of 350 nm - 1500 nm and 1500 nm - 6500 nm with demonstrated efficiency greater than 90% in near-infrared and mid-wave infrared. The multi-octave spectral beam combiner concept is realized using an integrated platform with silicon nitride waveguides and silicon waveguides. Simulated bandwidth is shown to be over four octaves, and measured bandwidth is shown over two octaves, limited by the availability of sources.

  12. Periodicity, chaos, and multiple attractors in a memristor-based Shinriki's circuit

    SciTech Connect

    Kengne, J.; Njitacke Tabekoueng, Z.; Kamdoum Tamba, V.; Nguomkam Negou, A.

    2015-10-15

    In this contribution, a novel memristor-based oscillator, obtained from Shinriki's circuit by substituting the nonlinear positive conductance with a first order memristive diode bridge, is introduced. The model is described by a continuous time four-dimensional autonomous system with smooth nonlinearities. The basic dynamical properties of the system are investigated including equilibria and stability, phase portraits, frequency spectra, bifurcation diagrams, and Lyapunov exponents' spectrum. It is found that in addition to the classical period-doubling and symmetry restoring crisis scenarios reported in the original circuit, the memristor-based oscillator experiences the unusual and striking feature of multiple attractors (i.e., coexistence of a pair of asymmetric periodic attractors with a pair of asymmetric chaotic ones) over a broad range of circuit parameters. Results of theoretical analyses are verified by laboratory experimental measurements.

  13. Dictionary-based image reconstruction for superresolution in integrated circuit imaging.

    PubMed

    Cilingiroglu, T Berkin; Uyar, Aydan; Tuysuzoglu, Ahmet; Karl, W Clem; Konrad, Janusz; Goldberg, Bennett B; Ünlü, M Selim

    2015-06-01

    Resolution improvement through signal processing techniques for integrated circuit imaging is becoming more crucial as the rapid decrease in integrated circuit dimensions continues. Although there is a significant effort to push the limits of optical resolution for backside fault analysis through the use of solid immersion lenses, higher order laser beams, and beam apodization, signal processing techniques are required for additional improvement. In this work, we propose a sparse image reconstruction framework which couples overcomplete dictionary-based representation with a physics-based forward model to improve resolution and localization accuracy in high numerical aperture confocal microscopy systems for backside optical integrated circuit analysis. The effectiveness of the framework is demonstrated on experimental data.

  14. Periodicity, chaos, and multiple attractors in a memristor-based Shinriki's circuit.

    PubMed

    Kengne, J; Njitacke Tabekoueng, Z; Kamdoum Tamba, V; Nguomkam Negou, A

    2015-10-01

    In this contribution, a novel memristor-based oscillator, obtained from Shinriki's circuit by substituting the nonlinear positive conductance with a first order memristive diode bridge, is introduced. The model is described by a continuous time four-dimensional autonomous system with smooth nonlinearities. The basic dynamical properties of the system are investigated including equilibria and stability, phase portraits, frequency spectra, bifurcation diagrams, and Lyapunov exponents' spectrum. It is found that in addition to the classical period-doubling and symmetry restoring crisis scenarios reported in the original circuit, the memristor-based oscillator experiences the unusual and striking feature of multiple attractors (i.e., coexistence of a pair of asymmetric periodic attractors with a pair of asymmetric chaotic ones) over a broad range of circuit parameters. Results of theoretical analyses are verified by laboratory experimental measurements.

  15. A New Automated Design Method Based on Machine Learning for CMOS Analog Circuits

    NASA Astrophysics Data System (ADS)

    Moradi, Behzad; Mirzaei, Abdolreza

    2016-11-01

    A new simulation based automated CMOS analog circuit design method which applies a multi-objective non-Darwinian-type evolutionary algorithm based on Learnable Evolution Model (LEM) is proposed in this article. The multi-objective property of this automated design of CMOS analog circuits is governed by a modified Strength Pareto Evolutionary Algorithm (SPEA) incorporated in the LEM algorithm presented here. LEM includes a machine learning method such as the decision trees that makes a distinction between high- and low-fitness areas in the design space. The learning process can detect the right directions of the evolution and lead to high steps in the evolution of the individuals. The learning phase shortens the evolution process and makes remarkable reduction in the number of individual evaluations. The expert designer's knowledge on circuit is applied in the design process in order to reduce the design space as well as the design time. The circuit evaluation is made by HSPICE simulator. In order to improve the design accuracy, bsim3v3 CMOS transistor model is adopted in this proposed design method. This proposed design method is tested on three different operational amplifier circuits. The performance of this proposed design method is verified by comparing it with the evolutionary strategy algorithm and other similar methods.

  16. Dynamics, Analysis and Implementation of a Multiscroll Memristor-Based Chaotic Circuit

    NASA Astrophysics Data System (ADS)

    Alombah, N. Henry; Fotsin, Hilaire; Ngouonkadi, E. B. Megam; Nguazon, Tekou

    This article introduces a novel four-dimensional autonomous multiscroll chaotic circuit which is derived from the actual simplest memristor-based chaotic circuit. A fourth circuit element — another inductor — is introduced to generate the complex behavior observed. A systematic study of the chaotic behavior is performed with the help of some nonlinear tools such as Lyapunov exponents, phase portraits, and bifurcation diagrams. Multiple scroll attractors are observed in Matlab, Pspice environments and also experimentally. We also observe the phenomenon of antimonotonicity, periodic and chaotic bubbles, multiple periodic-doubling bifurcations, Hopf bifurcations, crises and the phenomenon of intermittency. The chaotic dynamics of this circuit is realized by laboratory experiments, Pspice simulations, numerical and analytical investigations. It is observed that the results from the three environments agree to a great extent. This topology is likely convenient to be used to intentionally generate chaos in memristor-based chaotic circuit applications, given the fact that multiscroll chaotic systems have found important applications as broadband signal generators, pseudorandom number generators for communication engineering and also in biometric authentication.

  17. Commutation circuit for an HVDC circuit breaker

    DOEpatents

    Premerlani, W.J.

    1981-11-10

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

  18. Commutation circuit for an HVDC circuit breaker

    DOEpatents

    Premerlani, William J.

    1981-01-01

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

  19. Tools for probing local circuits: high-density silicon probes combined with optogenetics

    PubMed Central

    Buzsáki, György; Stark, Eran; Berényi, Antal; Khodagholy, Dion; Kipke, Daryl R.; Yoon, Euisik; Wise, Kensall

    2015-01-01

    To understand how function arises from the interactions between neurons, it is necessary to use methods that allow the monitoring of brain activity at the single-neuron, single-spike level and the targeted manipulation of the diverse neuron types selectively in a closed-loop manner. Large-scale recordings of neuronal spiking combined with optogenetic perturbation of identified individual neurons has emerged as a suitable method for such tasks in behaving animals. To fully exploit the potential power of these methods, multiple steps of technical innovation are needed. We highlight the current state-of-the-art in electrophysiological recording methods, combined with optogenetics, and discuss directions for progress. In addition, we point to areas where rapid development is in progress and discuss topics where near-term improvements are possible and needed. PMID:25856489

  20. Tools for probing local circuits: high-density silicon probes combined with optogenetics.

    PubMed

    Buzsáki, György; Stark, Eran; Berényi, Antal; Khodagholy, Dion; Kipke, Daryl R; Yoon, Euisik; Wise, Kensall D

    2015-04-01

    To understand how function arises from the interactions between neurons, it is necessary to use methods that allow the monitoring of brain activity at the single-neuron, single-spike level and the targeted manipulation of the diverse neuron types selectively in a closed-loop manner. Large-scale recordings of neuronal spiking combined with optogenetic perturbation of identified individual neurons has emerged as a suitable method for such tasks in behaving animals. To fully exploit the potential power of these methods, multiple steps of technical innovation are needed. We highlight the current state of the art in electrophysiological recording methods, combined with optogenetics, and discuss directions for progress. In addition, we point to areas where rapid development is in progress and discuss topics where near-term improvements are possible and needed.

  1. Ge/Si Integrated Circuit For Infrared Imaging

    NASA Technical Reports Server (NTRS)

    Fathauer, Robert W.

    1990-01-01

    Proposed integrated circuit consists of focal-plane array of metal/germanium Schottky-barrier photodetectors on same chip with silicon-based circuits that processes signals from photodetectors. Made compatible with underlying silicon-based circuitry by growing germanium epitaxially on silicon circuit wafers. Metal deposited in ultrahigh vacuum immediately after growth of germanium. Combination of described techniques results in high-resolution infrared-imaging circuits of superior performance.

  2. Novel Approach To Synthesis of Logic Circuits Based on Multifunctional Components

    NASA Astrophysics Data System (ADS)

    Crha, Adam; Růžička, Richard; Šimek, Václav

    2016-01-01

    Multifunctional logic continuously becomes an important way how to implement compact and cheap circuits with intrinsic reconfiguration features. Polymorphic electronics concept with its substantial technological independency opens a way to fulfil this objective through the adoption of emerging semiconductor technologies and advanced synthesis methods. The paper comes with a proposal of a novel synthesis method oriented on the exploitation of polymorphic electronics principles. Key part of it is based on Boolean divisor identification and function kernelling technique. The proposed method is evaluated with several test circuits.

  3. [Growth and mutation of Escherichia coli with suicide gene circuit based on quorum sensing].

    PubMed

    Gao, Qi; Zheng, Xuesong

    2013-06-01

    Constructing robust gene circuits is a fundamental work for synthetic biology. Bacteria with suicide gene circuit based on quorum-sensing will kill themselves in a controllable pattern upon certain cell density. In the media of different IPTG inducer concentration, we observed the growth and suicidal behavior of the Escherichia coli. Top10F' with such gene circuit, screened the mutants and determined their mutated loci. The results show that, with higher IPTG concentration, the more wild type bacteria were killed; as well the mutants emerged earlier and spread over the population more quickly. The sequence of plasmids in those mutants revealed that a transposon inserted into the luxR gene and therefore disrupted Quorum-Sensing of these individuals. Furthermore, the insertion sequence of the plasmid can solely result in the mutants escaping from suicide.

  4. Dendritic nonlinearities are tuned for efficient spike-based computations in cortical circuits.

    PubMed

    Ujfalussy, Balázs B; Makara, Judit K; Branco, Tiago; Lengyel, Máté

    2015-01-01

    Cortical neurons integrate thousands of synaptic inputs in their dendrites in highly nonlinear ways. It is unknown how these dendritic nonlinearities in individual cells contribute to computations at the level of neural circuits. Here, we show that dendritic nonlinearities are critical for the efficient integration of synaptic inputs in circuits performing analog computations with spiking neurons. We developed a theory that formalizes how a neuron's dendritic nonlinearity that is optimal for integrating synaptic inputs depends on the statistics of its presynaptic activity patterns. Based on their in vivo preynaptic population statistics (firing rates, membrane potential fluctuations, and correlations due to ensemble dynamics), our theory accurately predicted the responses of two different types of cortical pyramidal cells to patterned stimulation by two-photon glutamate uncaging. These results reveal a new computational principle underlying dendritic integration in cortical neurons by suggesting a functional link between cellular and systems--level properties of cortical circuits. PMID:26705334

  5. A New Power Flow Tracing Method Based on Directed Circuit

    NASA Astrophysics Data System (ADS)

    Zhang, Weimin; Guo, Xiaojing; Liu, Yaonian; Ni, Defu; Wang, Lina; Jia, Yanbing

    In this paper, a power-sharing principle is proposed, base on the generation of the directed path. The principle is used to calculate the contributions of individual generators and loads to line flows and the real power transfer among individual generators and loads that are significant to transmission open access. From the IEEE 14-bus power systems, the effectiveness and availability of the method are verified.

  6. Reconfigurable anisotropy and functional transformations with VO2-based metamaterial electric circuits

    NASA Astrophysics Data System (ADS)

    Savo, Salvatore; Zhou, You; Castaldi, Giuseppe; Moccia, Massimo; Galdi, Vincenzo; Ramanathan, Shriram; Sato, Yuki

    2015-04-01

    We demonstrate an innovative multifunctional artificial material that combines exotic metamaterial properties and the environmentally responsive nature of phase-change media. The tunable metamaterial is designed with the aid of two interwoven coordinate-transformation equations and implemented with a network of thin-film resistors and vanadium dioxide (VO2). The strong temperature dependence of VO2 electrical conductivity results in a significant modification of the resistor network behavior, and we provide experimental evidence for a reconfigurable metamaterial electric circuit that not only mimics a continuous medium, but is also capable of responding to thermal stimulation through dynamic variation of its spatial anisotropy. Upon external temperature change, the overall effective functionality of the material switches between a "truncated cloak" and a "concentrator" for electric currents. Possible applications may include adaptive matching resistor networks, multifunctional electronic devices, and equivalent artificial materials in the magnetic domain. Additionally, the proposed technology could also be relevant for thermal management of integrated circuits.

  7. Three-input majority logic gate and multiple input logic circuit based on DNA strand displacement.

    PubMed

    Li, Wei; Yang, Yang; Yan, Hao; Liu, Yan

    2013-06-12

    In biomolecular programming, the properties of biomolecules such as proteins and nucleic acids are harnessed for computational purposes. The field has gained considerable attention due to the possibility of exploiting the massive parallelism that is inherent in natural systems to solve computational problems. DNA has already been used to build complex molecular circuits, where the basic building blocks are logic gates that produce single outputs from one or more logical inputs. We designed and experimentally realized a three-input majority gate based on DNA strand displacement. One of the key features of a three-input majority gate is that the three inputs have equal priority, and the output will be true if any of the two inputs are true. Our design consists of a central, circular DNA strand with three unique domains between which are identical joint sequences. Before inputs are introduced to the system, each domain and half of each joint is protected by one complementary ssDNA that displays a toehold for subsequent displacement by the corresponding input. With this design the relationship between any two domains is analogous to the relationship between inputs in a majority gate. Displacing two or more of the protection strands will expose at least one complete joint and return a true output; displacing none or only one of the protection strands will not expose a complete joint and will return a false output. Further, we designed and realized a complex five-input logic gate based on the majority gate described here. By controlling two of the five inputs the complex gate can realize every combination of OR and AND gates of the other three inputs.

  8. Directed acyclic graph-based technology mapping of genetic circuit models.

    PubMed

    Roehner, Nicholas; Myers, Chris J

    2014-08-15

    As engineering foundations such as standards and abstraction begin to mature within synthetic biology, it is vital that genetic design automation (GDA) tools be developed to enable synthetic biologists to automatically select standardized DNA components from a library to meet the behavioral specification for a genetic circuit. To this end, we have developed a genetic technology mapping algorithm that builds on the directed acyclic graph (DAG) based mapping techniques originally used to select parts for digital electronic circuit designs and implemented it in our GDA tool, iBioSim. It is among the first genetic technology mapping algorithms to adapt techniques from electronic circuit design, in particular the use of a cost function to guide the search for an optimal solution, and perhaps that which makes the greatest use of standards for describing genetic function and structure to represent design specifications and component libraries. This paper demonstrates the use of our algorithm to map the specifications for three different genetic circuits against four randomly generated libraries of increasing size to evaluate its performance against both exhaustive search and greedy variants for finding optimal and near-optimal solutions.

  9. Analog Integrated Circuit for Motion Detection with Simple-Shape Recognition Based on Frog Vision System

    NASA Astrophysics Data System (ADS)

    Nishio, Kimihiro; Yonezu, Hiroo; Furukawa, Yuzo

    2007-09-01

    We proposed in this research a novel two-dimensional network based on the frog visual system, with a motion detection function and a newly developed simple-shape recognition function, for use in object discrimination by integrated circuits. Specifically, the network mimics the signal processing of the small-field cell in a frog brain, consisting of the tectum and thalamus, which generates signals of the motion and simple shape of an object. The proposed network is constructed from simple analog complementary metal oxide semiconductor (CMOS) circuits; a test chip of the proposed network was fabricated with a 1.2 μm CMOS process. Measurements on the chip clarified that the proposed network can generate signals of the moving direction, velocity, and simple shape, as well as perform information processing of the small-field cell. Results with the simulation program with integrated circuit emphasis (SPICE) showed that the analog circuits used in the network have low power consumption. Applications of the proposed network are expected to realize advanced vision chips with functions such as object discrimination and target tracking.

  10. Linear DNA for rapid prototyping of synthetic biological circuits in an Escherichia coli based TX-TL cell-free system.

    PubMed

    Sun, Zachary Z; Yeung, Enoch; Hayes, Clarmyra A; Noireaux, Vincent; Murray, Richard M

    2014-06-20

    Accelerating the pace of synthetic biology experiments requires new approaches for rapid prototyping of circuits from individual DNA regulatory elements. However, current testing standards require days to weeks due to cloning and in vivo transformation. In this work, we first characterized methods to protect linear DNA strands from exonuclease degradation in an Escherichia coli based transcription-translation cell-free system (TX-TL), as well as mechanisms of degradation. This enabled the use of linear DNA PCR products in TX-TL. We then compared expression levels and binding dynamics of different promoters on linear DNA and plasmid DNA. We also demonstrated assembly technology to rapidly build circuits entirely in vitro from separate parts. Using this strategy, we prototyped a four component genetic switch in under 8 h entirely in vitro. Rapid in vitro assembly has future applications for prototyping multiple component circuits if combined with predictive computational models.

  11. Recovery of metals from waste printed circuit boards by supercritical water pre-treatment combined with acid leaching process.

    PubMed

    Xiu, Fu-Rong; Qi, Yingying; Zhang, Fu-Shen

    2013-05-01

    Waste printed circuit boards (PCBs) contain a large number of metals such as Cu, Sn, Pb, Cd, Cr, Zn, and Mn. In this work, an efficient and environmentally friendly process for metals recovery from waste PCBs by supercritical water (SCW) pre-treatment combined with acid leaching was developed. In the proposed process, waste PCBs were pre-treated by SCW, then the separated solid phase product with concentrated metals was subjected to an acid leaching process for metals recovery. The effect of SCW pre-treatment on the recovery of different metals from waste PCBs was investigated. Two methods of SCW pre-treatment were studied: supercritical water oxidation (SCWO) and supercritical water depolymerization (SCWD). Experimental results indicated that SCWO and SCWD pre-treatment had significant effect on the recovery of different metals. SCWO pre-treatment was highly efficient for enhancing the recovery of Cu and Pb, and the recovery efficiency increased significantly with increasing pre-treatment temperature. The recovery efficiency of Cu and Pb for SCWO pre-treatment at 420°C was 99.8% and 80%, respectively, whereas most of the Sn and Cr were immobilized in the residue. The recovery of all studied metals was enhanced by SCWD pre-treatment and increased along with pre-treatment temperature. Up to 90% of Sn, Zn, Cr, Cd, and Mn could be recovered for SCWD pre-treatment at 440°C.

  12. AC Loss Calculation of REBCO Cables by the Combination of Electric Circuit Model and 2D Finite Element Method

    NASA Astrophysics Data System (ADS)

    Noji, H.

    This study investigates the losses in a two conducting-layer REBCO cable fabricated by researchers at Furukawa Electric Co. Ltd. The losses were calculated using a combination of my electric circuit (EC) model with a two-dimensional finite element method (2D FEM). The helical pitches of the tapes in each layer, P1 and P2, were adjusted to equalize the current in both cable layers, although the loss calculation assumed infinite helical pitches and the same current in each layer at first. The results showed that the losses depended on the relative tape-position angle between the layers (θ/θ'), because the vertical field between adjacent tapes in the same layer varied with θ/θ'. When simulating the real cable, the helical pitches were adjusted and the layer currents were calculated by the EC model. These currents were input to the 2D FEM to compute the losses. The losses changed along the cable length because the difference between P1 and P2 altered the θ/θ' along this direction. The average angle-dependent and position-dependent losses were equal and closely approximated the measured losses. As an example to reduce the loss in this cable, the angle and the helical pitches were fixed at θ/θ' = 0.5 and P1 = P2 = 100 mm (S-direction). The calculation with these conditions indicated that the loss is about one order of magnitude lower than the measurement.

  13. Synthetic biology devices and circuits for RNA-based 'smart vaccines': a propositional review.

    PubMed

    Andries, Oliwia; Kitada, Tasuku; Bodner, Katie; Sanders, Niek N; Weiss, Ron

    2015-02-01

    Nucleic acid vaccines have been gaining attention as an alternative to the standard attenuated pathogen or protein based vaccine. However, an unrealized advantage of using such DNA or RNA based vaccination modalities is the ability to program within these nucleic acids regulatory devices that would provide an immunologist with the power to control the production of antigens and adjuvants in a desirable manner by administering small molecule drugs as chemical triggers. Advances in synthetic biology have resulted in the creation of highly predictable and modular genetic parts and devices that can be composed into synthetic gene circuits with complex behaviors. With the recent advent of modified RNA gene delivery methods and developments in the RNA replicon platform, we foresee a future in which mammalian synthetic biologists will create genetic circuits encoded exclusively on RNA. Here, we review the current repertoire of devices used in RNA synthetic biology and propose how programmable 'smart vaccines' will revolutionize the field of RNA vaccination.

  14. Analysis and modelling of GaN Schottky-based circuits at millimeter wavelengths

    NASA Astrophysics Data System (ADS)

    Pardo, D.; Grajal, J.

    2015-11-01

    This work presents an analysis of the capabilities of GaN Schottky diodes for frequency multipliers and mixers at millimeter wavelengths. By using a Monte Carlo (MC) model of the diode coupled to a harmonic balance technique, the electrical and noise performances of these circuits are investigated. Despite the lower electron mobility of GaN compared to GaAs, multipliers based on GaN Schottky diodes can be competitive in the first stages of multiplier chains, due to the excellent power handling capabilities of this material. The performance of these circuits can be improved by taking advantage of the lateral Schottky diode structures based on AlGaN/GaN HEMT technology.

  15. Integrated Circuit-Based Biofabrication with Common Biomaterials for Probing Cellular Biomechanics.

    PubMed

    Sung, Chun-Yen; Yang, Chung-Yao; Yeh, J Andrew; Cheng, Chao-Min

    2016-02-01

    Recent advances in bioengineering have enabled the development of biomedical tools with modifiable surface features (small-scale architecture) to mimic extracellular matrices and aid in the development of well-controlled platforms that allow for the application of mechanical stimulation for studying cellular biomechanics. An overview of recent developments in common biomaterials that can be manufactured using integrated circuit-based biofabrication is presented. Integrated circuit-based biofabrication possesses advantages including mass and diverse production capacities for fabricating in vitro biomedical devices. This review highlights the use of common biomaterials that have been most frequently used to study cellular biomechanics. In addition, the influence of various small-scale characteristics on common biomaterial surfaces for a range of different cell types is discussed.

  16. Impact-Based Area Allocation for Yield Optimization in Integrated Circuits

    NASA Astrophysics Data System (ADS)

    Abraham, Billion; Widodo, Arif; Chen, Poki

    2016-06-01

    In analog integrated circuit (IC) layout, area allocation is a very important issue for achieving good mismatch cancellation. However, most IC layout papers focus only on layout strategy to reduce systematic mismatch. In 2006, an outstanding paper presenting area allocation strategy was published to introduce technique for random mismatch reduction. Instead of using general theoretical study to prove the strategy, this research presented close-to-optimum simulations only on case-bycase basis. The impact-based area allocation for yield optimization in integrated circuits is proposed in this chapter. To demonstrate the corresponding strategy, not only a theoretical analysis but also an integral nonlinearity-based yield simulation will be given to derive optimum area allocation for binary weighted current steering digital-to-analog converter (DAC). The result will be concluded to convince IC designers how to allocate area for critical devices in an optimum way.

  17. Design of readout circuit for microcantilever-based ripple uncooled infrared focal plane arrays

    NASA Astrophysics Data System (ADS)

    Cao, Junmin; Chen, Zhongjian; Lu, Wengao; Zhang, Yacong; Lei, Ke; Zhao, Baoying

    2009-07-01

    A readout integrated circuit (ROIC) for uncooled microcantilever infrared focal plane arrays (IRFPAs) based on capacitive readout is proposed. The ROIC is optimized according to noise modeling and analysis to reduce noise. An experimental chip of 16×16 FPAs readout circuit has been designed and fabricated using 0.35um CMOS technology. The measurement results showed that the power dissipation is 16.5mW from a 5V supply voltage at 50Hz frame rate, the linearity is 99.2% at the typical mode; the uniformity is larger than 97% and the equivalent noise charge (ENC) is below 150e. It is believed that the ROIC has a great potential in the applications of large-scale micro-cantilever-based uncooled IRFPAs.

  18. Synthetic biology devices and circuits for RNA-based 'smart vaccines': a propositional review.

    PubMed

    Andries, Oliwia; Kitada, Tasuku; Bodner, Katie; Sanders, Niek N; Weiss, Ron

    2015-02-01

    Nucleic acid vaccines have been gaining attention as an alternative to the standard attenuated pathogen or protein based vaccine. However, an unrealized advantage of using such DNA or RNA based vaccination modalities is the ability to program within these nucleic acids regulatory devices that would provide an immunologist with the power to control the production of antigens and adjuvants in a desirable manner by administering small molecule drugs as chemical triggers. Advances in synthetic biology have resulted in the creation of highly predictable and modular genetic parts and devices that can be composed into synthetic gene circuits with complex behaviors. With the recent advent of modified RNA gene delivery methods and developments in the RNA replicon platform, we foresee a future in which mammalian synthetic biologists will create genetic circuits encoded exclusively on RNA. Here, we review the current repertoire of devices used in RNA synthetic biology and propose how programmable 'smart vaccines' will revolutionize the field of RNA vaccination. PMID:25566800

  19. Student use of model-based reasoning when troubleshooting an electronic circuit

    NASA Astrophysics Data System (ADS)

    Lewandowski, Heather; Stetzer, Mackenzie; van de Bogart, Kevin; Dounas-Frazer, Dimitri

    2016-03-01

    Troubleshooting systems is an integral part of experimental physics in both research and educational settings. Accordingly, ability to troubleshoot is an important learning goal for undergraduate physics lab courses. We investigate students' model-based reasoning on a troubleshooting task using data collected in think-aloud interviews during which pairs of students from two institutions attempted to diagnose and repair a malfunctioning circuit. Our analysis scheme was informed by the Experimental Modeling Framework, which describes physicists' use of mathematical and conceptual models when reasoning about experimental systems. We show that system and subsystem models were crucial for the evaluation of repairs to the circuit and played an important role in some troubleshooting strategies. Finally, drawing on data from interviews with electronics instructors from a broad range of institution types, we outline recommendations for model-based approaches to teaching and learning troubleshooting skills.

  20. Student use of model-based reasoning when troubleshooting an electric circuit

    NASA Astrophysics Data System (ADS)

    Dounas-Frazer, Dimitri

    2016-05-01

    Troubleshooting systems is an integral part of experimental physics in both research and educational settings. Accordingly, ability to troubleshoot is an important learning goal for undergraduate physics lab courses. We investigate students' model-based reasoning on a troubleshooting task using data collected in think-aloud interviews during which pairs of students from two institutions attempted to diagnose and repair a malfunctioning circuit. Our analysis scheme was informed by the Experimental Modeling Framework, which describes physicists' use of mathematical and conceptual models when reasoning about experimental systems. We show that system and subsystem models were crucial for the evaluation of repairs to the circuit and played an important role in some troubleshooting strategies. Finally, drawing on data from interviews with electronics instructors from a broad range of institution types, we outline recommendations for model-based approaches to teaching and learning troubleshooting skills.

  1. Performance of in-pixel circuits for photon counting arrays (PCAs) based on polycrystalline silicon TFTs

    NASA Astrophysics Data System (ADS)

    Liang, Albert K.; Koniczek, Martin; Antonuk, Larry E.; El-Mohri, Youcef; Zhao, Qihua; Street, Robert A.; Lu, Jeng Ping

    2016-03-01

    Photon counting arrays (PCAs), defined as pixelated imagers which measure the absorbed energy of x-ray photons individually and record this information digitally, are of increasing clinical interest. A number of PCA prototypes with a 1 mm pixel-to-pixel pitch have recently been fabricated with polycrystalline silicon (poly-Si)—a thin-film technology capable of creating monolithic imagers of a size commensurate with human anatomy. In this study, analog and digital simulation frameworks were developed to provide insight into the influence of individual poly-Si transistors on pixel circuit performance—information that is not readily available through empirical means. The simulation frameworks were used to characterize the circuit designs employed in the prototypes. The analog framework, which determines the noise produced by individual transistors, was used to estimate energy resolution, as well as to identify which transistors contribute the most noise. The digital framework, which analyzes how well circuits function in the presence of significant variations in transistor properties, was used to estimate how fast a circuit can produce an output (referred to as output count rate). In addition, an algorithm was developed and used to estimate the minimum pixel pitch that could be achieved for the pixel circuits of the current prototypes. The simulation frameworks predict that the analog component of the PCA prototypes could have energy resolution as low as 8.9% full width at half maximum (FWHM) at 70 keV; and the digital components should work well even in the presence of significant thin-film transistor (TFT) variations, with the fastest component having output count rates as high as 3 MHz. Finally, based on conceivable improvements in the underlying fabrication process, the algorithm predicts that the 1 mm pitch of the current PCA prototypes could be reduced significantly, potentially to between ~240 and 290 μm.

  2. Performance of in-pixel circuits for photon counting arrays (PCAs) based on polycrystalline silicon TFTs.

    PubMed

    Liang, Albert K; Koniczek, Martin; Antonuk, Larry E; El-Mohri, Youcef; Zhao, Qihua; Street, Robert A; Lu, Jeng Ping

    2016-03-01

    Photon counting arrays (PCAs), defined as pixelated imagers which measure the absorbed energy of x-ray photons individually and record this information digitally, are of increasing clinical interest. A number of PCA prototypes with a 1 mm pixel-to-pixel pitch have recently been fabricated with polycrystalline silicon (poly-Si)-a thin-film technology capable of creating monolithic imagers of a size commensurate with human anatomy. In this study, analog and digital simulation frameworks were developed to provide insight into the influence of individual poly-Si transistors on pixel circuit performance-information that is not readily available through empirical means. The simulation frameworks were used to characterize the circuit designs employed in the prototypes. The analog framework, which determines the noise produced by individual transistors, was used to estimate energy resolution, as well as to identify which transistors contribute the most noise. The digital framework, which analyzes how well circuits function in the presence of significant variations in transistor properties, was used to estimate how fast a circuit can produce an output (referred to as output count rate). In addition, an algorithm was developed and used to estimate the minimum pixel pitch that could be achieved for the pixel circuits of the current prototypes. The simulation frameworks predict that the analog component of the PCA prototypes could have energy resolution as low as 8.9% full width at half maximum (FWHM) at 70 keV; and the digital components should work well even in the presence of significant thin-film transistor (TFT) variations, with the fastest component having output count rates as high as 3 MHz. Finally, based on conceivable improvements in the underlying fabrication process, the algorithm predicts that the 1 mm pitch of the current PCA prototypes could be reduced significantly, potentially to between ~240 and 290 μm.

  3. To Compare the Effects of Computer Based Learning and the Laboratory Based Learning on Students' Achievement Regarding Electric Circuits

    ERIC Educational Resources Information Center

    Bayrak, Bekir; Kanli, Uygar; Ingec, Sebnem Kandil

    2007-01-01

    In this study, the research problem was: "Is the computer based physics instruction as effective as laboratory intensive physics instruction with regards to academic success on electric circuits 9th grade students?" For this research of experimental quality the design of pre-test and post-test are applied with an experiment and a control group.…

  4. To Compare the Effects of Computer Based Learning and the Laboratory Based Learning on Students' Achievement Regarding Electric Circuits

    ERIC Educational Resources Information Center

    Bayrak, Bekir; Kanli, Uygar; Kandil Ingeç, Sebnem

    2007-01-01

    In this study, the research problem was: "Is the computer based physics instruction as effective as laboratory intensive physics instruction with regards to academic success on electric circuits 9th grade students?" For this research of experimental quality the design of pre-test and post-test are applied with an experiment and a control…

  5. Towards Practical Application of Paper based Printed Circuits: Capillarity Effectively Enhances Conductivity of the Thermoplastic Electrically Conductive Adhesives

    PubMed Central

    Wu, Haoyi; Chiang, Sum Wai; Lin, Wei; Yang, Cheng; Li, Zhuo; Liu, Jingping; Cui, Xiaoya; Kang, Feiyu; Wong, Ching Ping

    2014-01-01

    Direct printing nanoparticle-based conductive inks onto paper substrates has encountered difficulties e.g. the nanoparticles are prone to penetrate into the pores of the paper and become partially segmented, and the necessary low-temperature-sintering process is harmful to the dimension-stability of paper. Here we prototyped the paper-based circuit substrate in combination with printed thermoplastic electrically conductive adhesives (ECA), which takes the advantage of the capillarity of paper and thus both the conductivity and mechanical robustness of the printed circuitsweredrastically improved without sintering process. For instance, the electrical resistivity of the ECA specimen on a pulp paper (6 × 10−5Ω·cm, with 50 wt% loading of Ag) was only 14% of that on PET film than that on PET film. This improvement has been found directly related to the sizing degree of paper, in agreement with the effective medium approximation simulation results in this work. The thermoplastic nature also enables excellent mechanical strength of the printed ECA to resist repeated folding. Considering the generality of the process and the wide acceptance of ECA technique in the modern electronic packages, this method may find vast applications in e.g. circuit boards, capacitive touch pads, and radio frequency identification antennas, which have been prototyped in the manuscript. PMID:25182052

  6. New circular polarization selective surface concepts based on the Pierrot cell using printed circuit technology

    NASA Astrophysics Data System (ADS)

    Lopez, Humberto Israel

    This M.A.Sc. thesis focuses on finding an alternative method of constructing a circular polarization selective surface (CPSS) based on the Pierrot cell using the standard printed circuit technology. This technique uses a folded flexible substrate, which enables the implementation of the 3D Pierrot cells on a single metal layer defined with precision printed circuit board techniques, without the need for metalized via holes. Different topologies of the CPSS are analyzed in order to make the CPSS more efficient in terms of bandwidth and independence on the direction of propagation of the incident wave. A left-hand CPSS is designed to illustrate the benefits of the proposed approach. The first approach is a simple Pierrot unit cell CPSS which is optimized to have good reflection and transmission coefficients. A prototype is built and then characterized in a test bench operating in the K-band. For the fabricated prototype, the transmission coefficients of plane waves at normal incidence in the right-hand and the left-hand circular polarizations are --0.48 dB and --24 dB respectively. The bandwidth for which the transmission coefficient of the incident left-handed incident wave is greater than --3 dB was of 17.6%. These results are in good agreement with simulations results obtained with HFSS. A second variant considered is a Pierrot cell with a series load in the middle segment. With this cell it is possible to equalize the frequencies giving a better operation in the right- and left-handed circular polarized waves. There is an improvement for the co-pol to cross-pol ratio for the RHCP waves of 10 dB at 20 GHz. The added load does not affect the performance for the left-hand circular polarization, as expected. The third modification is a Pierrot cell at 90 degrees. This cell is designed to allow the combination of two Pierrot cells working at different frequencies on the same substrate in order to increase the frequency bandwidth of the CPSS. Unfortunately, the axial

  7. Photolithography-Based Patterning of Liquid Metal Interconnects for Monolithically Integrated Stretchable Circuits.

    PubMed

    Park, Chan Woo; Moon, Yu Gyeong; Seong, Hyejeong; Jung, Soon Won; Oh, Ji-Young; Na, Bock Soon; Park, Nae-Man; Lee, Sang Seok; Im, Sung Gap; Koo, Jae Bon

    2016-06-22

    We demonstrate a new patterning technique for gallium-based liquid metals on flat substrates, which can provide both high pattern resolution (∼20 μm) and alignment precision as required for highly integrated circuits. In a very similar manner as in the patterning of solid metal films by photolithography and lift-off processes, the liquid metal layer painted over the whole substrate area can be selectively removed by dissolving the underlying photoresist layer, leaving behind robust liquid patterns as defined by the photolithography. This quick and simple method makes it possible to integrate fine-scale interconnects with preformed devices precisely, which is indispensable for realizing monolithically integrated stretchable circuits. As a way for constructing stretchable integrated circuits, we propose a hybrid configuration composed of rigid device regions and liquid interconnects, which is constructed on a rigid substrate first but highly stretchable after being transferred onto an elastomeric substrate. This new method can be useful in various applications requiring both high-resolution and precisely aligned patterning of gallium-based liquid metals. PMID:27250997

  8. Photolithography-Based Patterning of Liquid Metal Interconnects for Monolithically Integrated Stretchable Circuits.

    PubMed

    Park, Chan Woo; Moon, Yu Gyeong; Seong, Hyejeong; Jung, Soon Won; Oh, Ji-Young; Na, Bock Soon; Park, Nae-Man; Lee, Sang Seok; Im, Sung Gap; Koo, Jae Bon

    2016-06-22

    We demonstrate a new patterning technique for gallium-based liquid metals on flat substrates, which can provide both high pattern resolution (∼20 μm) and alignment precision as required for highly integrated circuits. In a very similar manner as in the patterning of solid metal films by photolithography and lift-off processes, the liquid metal layer painted over the whole substrate area can be selectively removed by dissolving the underlying photoresist layer, leaving behind robust liquid patterns as defined by the photolithography. This quick and simple method makes it possible to integrate fine-scale interconnects with preformed devices precisely, which is indispensable for realizing monolithically integrated stretchable circuits. As a way for constructing stretchable integrated circuits, we propose a hybrid configuration composed of rigid device regions and liquid interconnects, which is constructed on a rigid substrate first but highly stretchable after being transferred onto an elastomeric substrate. This new method can be useful in various applications requiring both high-resolution and precisely aligned patterning of gallium-based liquid metals.

  9. Technical considerations on confocal based fluorescence micro-optical sectioning tomography for visualizing brain circuits

    NASA Astrophysics Data System (ADS)

    Qi, Xiaoli; Lv, Xiaohua; Xiong, Hanqing; Yan, Cheng; Chen, Jianling; Gong, Hui; Luo, Qingming; Zeng, Shaoqun

    2014-03-01

    Imaging brain circuits is the basis for us to understand brain function and dysfunction. However, imaging axon at micrometer resolution while tracing the centimeter-scale axon projection across the whole-brain is still challenging. Here, we developed a fluorescence micro-optical sectioning tomography (fMOST) imaging system based on confocal fluorescence imaging scheme that can obtain whole brain image stack for visualizing brain circuits at neurite level. We use confocal detection to remove fluorescence background to clearly see one single neurite and use acoustical optical deflector (AOD), an inertia-free beam scanner to realize fast and prolonged stable imaging. We had acquired several complete datasets of whole-mouse brain at a one-micron voxel resolution. Based on these datasets, the uninterrupted tracing of brain-wide, long-distance axonal projections was demonstrated for the first time using a systematic reconstruction and annotation pipeline. Our method is believed to open an avenue to exploring both local and long-distance neural circuits that are related to brain functions and brain diseases down to the neurite level.

  10. Photonic crystal ring resonator based optical filters for photonic integrated circuits

    NASA Astrophysics Data System (ADS)

    Robinson, S.

    2014-10-01

    In this paper, a two Dimensional (2D) Photonic Crystal Ring Resonator (PCRR) based optical Filters namely Add Drop Filter, Bandpass Filter, and Bandstop Filter are designed for Photonic Integrated Circuits (PICs). The normalized output response of the filters is obtained using 2D Finite Difference Time Domain (FDTD) method and the band diagram of periodic and non-periodic structure is attained by Plane Wave Expansion (PWE) method. The size of the device is minimized from a scale of few tens of millimeters to the order of micrometers. The overall size of the filters is around 11.4 μm × 11.4 μm which is highly suitable of photonic integrated circuits.

  11. Photonic crystal ring resonator based optical filters for photonic integrated circuits

    SciTech Connect

    Robinson, S.

    2014-10-15

    In this paper, a two Dimensional (2D) Photonic Crystal Ring Resonator (PCRR) based optical Filters namely Add Drop Filter, Bandpass Filter, and Bandstop Filter are designed for Photonic Integrated Circuits (PICs). The normalized output response of the filters is obtained using 2D Finite Difference Time Domain (FDTD) method and the band diagram of periodic and non-periodic structure is attained by Plane Wave Expansion (PWE) method. The size of the device is minimized from a scale of few tens of millimeters to the order of micrometers. The overall size of the filters is around 11.4 μm × 11.4 μm which is highly suitable of photonic integrated circuits.

  12. Laser-induced breakdown spectroscopy (LIBS) combined with hyperspectral imaging for the evaluation of printed circuit board composition.

    PubMed

    Carvalho, Rodrigo R V; Coelho, Jomarc A O; Santos, Jozemir M; Aquino, Francisco W B; Carneiro, Renato L; Pereira-Filho, Edenir R

    2015-03-01

    In this study, laser-induced breakdown spectroscopy (LIBS) was combined with chemometric strategies (PCA, Principal Component Analysis) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) to investigate the metal composition of a printed circuit board (PCB) sample from a mobile phone. Scanning electron microscopy-EDS was used for two main reasons: it was possible at the same time to visualize the sample surface, craters (made by the laser pulses) and also the chemical composition of the samples. A 30 mm×40 mm area of the mobile phone PCB sample, which was manufactured in 2011, was investigated. In this case, a matrix with 30 rows and 40 columns (1200 points) was analyzed, and 10 pulses were performed at each point. A total of 12,000 emission spectra were recorded in the wavelength range from 186 to 1040 nm. After an initial exploratory investigation using PCA, 18 emission lines were selected (representing the elements Al, Au, Ba, Ca, Co, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Sb, Si, Sn, Ti and Zn) and then normalized by the relative intensities, and a new PCA was calculated with the autoscaled data. For example, Au and Si were mainly observed in the superficial electrical contacts and in the bulk of the PCB, respectively. A second sample (a mouse PCB) was also analyzed and Pb (emission lines 357.273, 363.956, 368.346, 373.994 and 405.780 nm) was identified in the solders. In addition, this element was determined using FAAS (flame atomic absorption spectrometry) and the Pb concentration was around 25% (w/w). This study opens the possibility for improved recycling processes and the chemical investigation of solid samples measuring a few millimeters in dimension without sample preparation.

  13. Design and characterization of a readout circuit for FET-based THz imaging

    NASA Astrophysics Data System (ADS)

    Domingues, Suzana; Perenzoni, Daniele; Perenzoni, Matteo; Stoppa, David

    2014-05-01

    A switched-capacitor integrator readout circuit for FET-based terahertz (THz) detectors was fabricated in a 0.13 μm standard CMOS technology. The designed readout circuit is suitable for implementation in pixel arrays due to its compact size and power consumption. In order to find the optimum bias point of the FET detector, responsivity, noise equivalent power (NEP) and signal-to-noise ratio (SNR) curves in function of the FET gate voltage (VG) have been measured for an arbitrary number of 10 accumulation cycles and two different operating clock frequencies. A responsivity peak of 1.8 kV/W was obtained with a clock frequency of 200 kHz, and of 1.3 kV/W at 400 kHz. A minimum NEP of 7.3 nW/√Hz was obtained with a 400 kHz clock frequency, while at 200 kHz the NEP is 8.5 nW/√Hz. The presented THz measurements with 100 accumulation cycles at 200 kHz and 400 kHz clock frequencies show a SNR improvement after each operation cycle, which means 500 and 1000 measurements per second with on-off modulation of the source, respectively. A test structure containing only a FET detector and a bowtie THz antenna was used to evaluate the impact of the readout circuit in the FET THz detection.

  14. Dendritic nonlinearities are tuned for efficient spike-based computations in cortical circuits

    PubMed Central

    Ujfalussy, Balázs B; Makara, Judit K; Branco, Tiago; Lengyel, Máté

    2015-01-01

    Cortical neurons integrate thousands of synaptic inputs in their dendrites in highly nonlinear ways. It is unknown how these dendritic nonlinearities in individual cells contribute to computations at the level of neural circuits. Here, we show that dendritic nonlinearities are critical for the efficient integration of synaptic inputs in circuits performing analog computations with spiking neurons. We developed a theory that formalizes how a neuron's dendritic nonlinearity that is optimal for integrating synaptic inputs depends on the statistics of its presynaptic activity patterns. Based on their in vivo preynaptic population statistics (firing rates, membrane potential fluctuations, and correlations due to ensemble dynamics), our theory accurately predicted the responses of two different types of cortical pyramidal cells to patterned stimulation by two-photon glutamate uncaging. These results reveal a new computational principle underlying dendritic integration in cortical neurons by suggesting a functional link between cellular and systems--level properties of cortical circuits. DOI: http://dx.doi.org/10.7554/eLife.10056.001 PMID:26705334

  15. Circuit-QED-based scalable architectures for quantum information processing with superconducting qubits

    NASA Astrophysics Data System (ADS)

    Billangeon, P.-M.; Tsai, J. S.; Nakamura, Y.

    2015-03-01

    We discuss different ways of generating entanglement in the original picture of circuit QED (XcQED) and several restrictions that arise in the context of a large-scale quantum architecture. To alleviate some of the issues posed by the presence of the nonlinearities inherent to these systems, we introduce a layout for circuit QED, wherein an artificial atom is coupled to a quantized radiation field via its longitudinal degree of freedom (ZcQED). This system is akin to ion traps used in atomic physics, but it relies on fixed coupling between the atom and the resonator. We describe a scalable architecture for processing quantum information with superconducting qubits, which is free from any type of residual interaction between the atomic and photonic degrees of freedom. Tunable interactions can be realized based on sideband transitions, and the system can be operated out of the Lamb-Dicke regime, allowing it to benefit from the possibility of achieving large coupling strengths between atoms and resonators. We also discuss a readout scheme that does not require any extra circuits and allows a qubit-specific measurement of the state of the quantum register inspired by the electron shelving technique. This scheme is quantum nondemolition (QND)-like, and allows for single-shot determination of the qubit states.

  16. Circuit Training.

    ERIC Educational Resources Information Center

    Nelson, Jane B.

    1998-01-01

    Describes a research-based activity for high school physics students in which they build an LC circuit and find its resonant frequency of oscillation using an oscilloscope. Includes a diagram of the apparatus and an explanation of the procedures. (DDR)

  17. Nonvolatile Ferroelectric Memory Circuit Using Black Phosphorus Nanosheet-Based Field-Effect Transistors with P(VDF-TrFE) Polymer.

    PubMed

    Lee, Young Tack; Kwon, Hyeokjae; Kim, Jin Sung; Kim, Hong-Hee; Lee, Yun Jae; Lim, Jung Ah; Song, Yong-Won; Yi, Yeonjin; Choi, Won-Kook; Hwang, Do Kyung; Im, Seongil

    2015-10-27

    Two-dimensional van der Waals (2D vdWs) materials are a class of new materials that can provide important resources for future electronics and materials sciences due to their unique physical properties. Among 2D vdWs materials, black phosphorus (BP) has exhibited significant potential for use in electronic and optoelectronic applications because of its allotropic properties, high mobility, and direct and narrow band gap. Here, we demonstrate a few-layered BP-based nonvolatile memory transistor with a poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)) ferroelectric top gate insulator. Experiments showed that our BP-based ferroelectric transistors operate satisfactorily at room temperature in ambient air and exhibit a clear memory window. Unlike conventional ambipolar BP transistors, our ferroelectric transistors showed only p-type characteristics due to the carbon-fluorine (C-F) dipole effect of the P(VDF-TrFE) layer, as well as the highest linear mobility value of 1159 cm(2) V(-1) s(-1) with a 10(3) on/off current ratio. For more advanced memory applications beyond unit memory devices, we implemented two memory inverter circuits, a resistive-load inverter circuit and a complementary inverter circuit, combined with an n-type molybdenum disulfide (MoS2) nanosheet. Our memory inverter circuits displayed a clear memory window of 15 V and memory output voltage efficiency of 95%.

  18. The Strutjet Rocket Based Combined Cycle Engine

    NASA Technical Reports Server (NTRS)

    Siebenhaar, A.; Bulman, M. J.; Bonnar, D. K.

    1998-01-01

    The multi stage chemical rocket has been established over many years as the propulsion System for space transportation vehicles, while, at the same time, there is increasing concern about its continued affordability and rather involved reusability. Two broad approaches to addressing this overall launch cost problem consist in one, the further development of the rocket motor, and two, the use of airbreathing propulsion to the maximum extent possible as a complement to the limited use of a conventional rocket. In both cases, a single-stage-to-orbit (SSTO) vehicle is considered a desirable goal. However, neither the "all-rocket" nor the "all-airbreathing" approach seems realizable and workable in practice without appreciable advances in materials and manufacturing. An affordable system must be reusable with minimal refurbishing on-ground, and large mean time between overhauls, and thus with high margins in design. It has been suggested that one may use different engine cycles, some rocket and others airbreathing, in a combination over a flight trajectory, but this approach does not lead to a converged solution with thrust-to-mass, specific impulse, and other performance and operational characteristics that can be obtained in the different engines. The reason is this type of engine is simply a combination of different engines with no commonality of gas flowpath or components, and therefore tends to have the deficiencies of each of the combined engines. A further development in this approach is a truly combined cycle that incorporates a series of cycles for different modes of propulsion along a flight path with multiple use of a set of components and an essentially single gas flowpath through the engine. This integrated approach is based on realizing the benefits of both a rocket engine and airbreathing engine in various combinations by a systematic functional integration of components in an engine class usually referred to as a rocket-based combined cycle (RBCC) engine

  19. Terahertz applications of integrated circuits based on intrinsic Josephson junctions in high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Wang, Huabing; Wu, Peiheng; Yamashita, Tsutomu

    2001-10-01

    Using a newly developed double-side fabrication method, an IJJ stack plus a bow-tie antenna and chokes were integrated in a slice 200 nm thick and singled out from inside a bulk Bi2Sr2CaCu2O8+x (BSCCO) single crystal. The junctions in the fabricated stack were very uniform, and the number of junctions involved was rather controllable. In addition to this method, which can be used to fabricate integrated circuits based on intrinsic Josephson junctions in high temperature (Tc) superconductors, also reported will be terahertz responses of IJJs, and the possible applications in quantum voltage standard, spectroscopy, and so on.

  20. Circuit for reducing power consumption in battery operated microprocessor based systems

    SciTech Connect

    Boyd, J.C.

    1980-05-13

    In a microprocessor based system, wherein at least one microprocessor is battery powered, a power strobe circuit includes an analog switch for connecting the battery to the microprocessor only during programmed task performance. Upon completion of task performance, the microprocessor generates signals which trigger the analog switch to open, thereby deenergizing the microprocessor and to enable an external timer. After a predetermined period of time, which may be fixed in the timer or programmed, the timer causes the switch to reclose, thereby energizing the microprocessor for performance of another programmed task.

  1. Design of mid-infrared ultra-wideband metallic absorber based on circuit theory

    NASA Astrophysics Data System (ADS)

    Arik, Kamalodin; Abdollahramezani, Sajjad; Farajollahi, Saeed; Khavasi, Amin; Rejaei, Behzad

    2016-12-01

    An ultra-broadband absorber of light is proposed by using periodic array of ultra-thin metallic ribbons on top of a lossless quarter-wavelength dielectric spacer placed on a metallic reflector. We propose a fully analytical circuit model for the structure, and then the absorber is duly designed based on the impedance matching concept. As a result, normalized bandwidth of 99.5% is realized by the proposed absorbing structure in mid-infrared regime. Performing a numerical optimization algorithm, we could also reach to normalized bandwidth of 103%.

  2. Hidden circuits and argumentation

    NASA Astrophysics Data System (ADS)

    Leinonen, Risto; Kesonen, Mikko H. P.; Hirvonen, Pekka E.

    2016-11-01

    Despite the relevance of DC circuits in everyday life and schools, they have been shown to cause numerous learning difficulties at various school levels. In the course of this article, we present a flexible method for teaching DC circuits at lower secondary level. The method is labelled as hidden circuits, and the essential idea underlying hidden circuits is in hiding the actual wiring of DC circuits, but to make their behaviour evident for pupils. Pupils are expected to find out the wiring of the circuit which should enhance their learning of DC circuits. We present two possible ways to utilise hidden circuits in a classroom. First, they can be used to test and enhance pupils’ conceptual understanding when pupils are expected to find out which one of the offered circuit diagram options corresponds to the actual circuit shown. This method aims to get pupils to evaluate the circuits holistically rather than locally, and as a part of that aim this method highlights any learning difficulties of pupils. Second, hidden circuits can be used to enhance pupils’ argumentation skills with the aid of argumentation sheet that illustrates the main elements of an argument. Based on the findings from our co-operating teachers and our own experiences, hidden circuits offer a flexible and motivating way to supplement teaching of DC circuits.

  3. CIRCUITS FOR CURRENT MEASUREMENTS

    DOEpatents

    Cox, R.J.

    1958-11-01

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

  4. Clinical Performance and Biocompatibility of Novel Hyaluronan-Based Heparin-Bonded Extracorporeal Circuits

    PubMed Central

    Gunaydin, Serdar; Mccusker, Kevin; Vijay, Venkataramana

    2005-01-01

    Abstract: We tested documented in vitro and ex vivo advantages of novel hyaluronan based heparin bonded extracorporeal circuits in a prospective randomized study. During the period from June until September 2005, 40 patients undergoing reoperation for coronary artery bypass grafting were allocated into two equal groups (n = 20): Group 1 was treated with hyaluronan-based heparin-bonded circuits and group 2 was treated with uncoated control circuits. Complete blood count, fibrinogen, albumin, C3a, interleukin-2 levels, and thromboelastographic data were documented after induction of anesthesia (T1) and heparin administration before cardiopulmonary bypass (CPB) (T2), 15 minutes after initiation of CPB (T3), before cessation of CPB (T4), 15 minutes after reversal with protamine (T5), and the first postoperative day at 8:00 a.m. (T6). Hollow fibers were collected for consecutive biomaterial analysis by optical and scanning electron microscopy (SEM). Desorbed protein deposition on fibers was compared by spectrophotometry. Leukocyte counts were lower in T4-T6 in group 1 (p < .05). Platelet counts demonstrated significant differences at T4 and T5 in coated group (p < .05). Albumin and fibrinogen levels were better preserved in Group 1 at T4, T5 and T4, T6, consecutively (p < .05). C3a and IL-2 levels were lower at T3-T5 and T4-T5 in intervention group (p < .05). Postoperative hemorrhage was 412 ± 50 mL in group 1 and 684 ± 50 ml in group 2 (p < .05). Respiratory support time was shorter in group 1 versus control (p < .05). Platelet adhesion was significantly lower in intervention group. Amount of desorbed protein was 1.44 ± 0.01 mg/dL in group 1 and 1.94 ± 0.01 mg/dL in control (p < .05). SEM and spectrophotometry demonstrated better surface preservation in the hyaluronan coated group. Novel hyaluronan-based heparin-bonded circuits reduce platelet adhesion-aggregation and protein adsorption and provide better perioperative clinical parameters through platelet, albumin

  5. A method for state-of-charge estimation of LiFePO4 batteries based on a dual-circuit state observer

    NASA Astrophysics Data System (ADS)

    Tang, Xiaopeng; Wang, Yujie; Chen, Zonghai

    2015-11-01

    Estimation of state-of-charge (SOC) is a key criterion to evaluate the battery management system (BMS). Due to the flat open-circuit voltage (OCV)-SOC curve of LiFePO4 batteries, it is a great challenge to estimate the SOC accurately. Here we present a dual-circuit state observer for SOC estimation of LiFePO4 batteries. It is a combination of an open loop based current integrator and a proportional-integral (PI) based state observer. We also employed an easy but practical drifting current corrector to restrain the influence of the drifting current. The experiment results show that error of the estimated SOC is less than 2.5% by the proposed method when the initial SOC is unknown. We proved that with no matrix operations, the proposed method is lighted-weighted and high efficient, which is suitable for embedded systems.

  6. A Voltage Mode Memristor Bridge Synaptic Circuit with Memristor Emulators

    PubMed Central

    Sah, Maheshwar Pd.; Yang, Changju; Kim, Hyongsuk; Chua, Leon

    2012-01-01

    A memristor bridge neural circuit which is able to perform signed synaptic weighting was proposed in our previous study, where the synaptic operation was verified via software simulation of the mathematical model of the HP memristor. This study is an extension of the previous work advancing toward the circuit implementation where the architecture of the memristor bridge synapse is built with memristor emulator circuits. In addition, a simple neural network which performs both synaptic weighting and summation is built by combining memristor emulators-based synapses and differential amplifier circuits. The feasibility of the memristor bridge neural circuit is verified via SPICE simulations. PMID:22737026

  7. A voltage mode memristor bridge synaptic circuit with memristor emulators.

    PubMed

    Sah, Maheshwar Pd; Yang, Changju; Kim, Hyongsuk; Chua, Leon

    2012-01-01

    A memristor bridge neural circuit which is able to perform signed synaptic weighting was proposed in our previous study, where the synaptic operation was verified via software simulation of the mathematical model of the HP memristor. This study is an extension of the previous work advancing toward the circuit implementation where the architecture of the memristor bridge synapse is built with memristor emulator circuits. In addition, a simple neural network which performs both synaptic weighting and summation is built by combining memristor emulators-based synapses and differential amplifier circuits. The feasibility of the memristor bridge neural circuit is verified via SPICE simulations.

  8. Computational investigation of rocket based combined cycle

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao-bo; Wang, Zhan-xue; Liu, Zeng-wen

    2013-03-01

    Based on Computational Fluid Dynamic technology, the mixing process of Rocket Based Combined Cycle (RBCC) propulsion system is researched. The idea of RBCC propulsion system means combining rocket engine with ramjet engine effectively, which can flight from sea level to high altitude in wide Mach ranges. In order to analyze how the length of the mixing part affects mixing process, different length of mixing part are researched. As it is indicated, with a constant Mach number, increasing the length of mixing part makes main flow and second flow mix more evenly. Moreover, the length of mixing part has a slight impact on the thrust. Obviously the main consequence of increasing the length of mixing part is promoting the mix of main flow and second flow. Therefore, in order to decrease the weight of aircraft, it is of importance to reduce the length. Through comparing distribution of different cases, when working in the situation of maximum power, the flow in the nozzle of rocket engine is under expansion, while that in the nozzle is fully expanded. Nevertheless, in the case of high altitude and high Mach number, there exists a vortex in the nozzle of rocket engine because of over expansion; meanwhile, the flow in the nozzle is under expansion. Therefore, it is necessary to adjust nozzle throat area in order to increase the thrust of RBCC at high altitude.

  9. Electrical Circuit Simulation Code

    SciTech Connect

    Wix, Steven D.; Waters, Arlon J.; Shirley, David

    2001-08-09

    Massively-Parallel Electrical Circuit Simulation Code. CHILESPICE is a massively-arallel distributed-memory electrical circuit simulation tool that contains many enhanced radiation, time-based, and thermal features and models. Large scale electronic circuit simulation. Shared memory, parallel processing, enhance convergence. Sandia specific device models.

  10. Open-circuit sensitivity model based on empirical parameters for a capacitive-type MEMS acoustic sensor

    NASA Astrophysics Data System (ADS)

    Lee, Jaewoo; Jeon, J. H.; Je, C. H.; Lee, S. Q.; Yang, W. S.; Lee, S.-G.

    2016-03-01

    An empirical-based open-circuit sensitivity model for a capacitive-type MEMS acoustic sensor is presented. To intuitively evaluate the characteristic of the open-circuit sensitivity, the empirical-based model is proposed and analysed by using a lumped spring-mass model and a pad test sample without a parallel plate capacitor for the parasitic capacitance. The model is composed of three different parameter groups: empirical, theoretical, and mixed data. The empirical residual stress from the measured pull-in voltage of 16.7 V and the measured surface topology of the diaphragm were extracted as +13 MPa, resulting in the effective spring constant of 110.9 N/m. The parasitic capacitance for two probing pads including the substrate part was 0.25 pF. Furthermore, to verify the proposed model, the modelled open-circuit sensitivity was compared with the measured value. The MEMS acoustic sensor had an open- circuit sensitivity of -43.0 dBV/Pa at 1 kHz with a bias of 10 V, while the modelled open- circuit sensitivity was -42.9 dBV/Pa, which showed good agreement in the range from 100 Hz to 18 kHz. This validates the empirical-based open-circuit sensitivity model for designing capacitive-type MEMS acoustic sensors.

  11. 670-GHz Schottky Diode-Based Subharmonic Mixer with CPW Circuits and 70-GHz IF

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Goutam; Schlecht, Erich T.; Lee, Choonsup; Lin, Robert H.; Gill, John J.; Mehdi, Imran; Sin, Seth; Deal, William; Loi, Kwok K.; Nam, Peta; Rodriguez, Bryan

    2012-01-01

    GaAs-based, sub-harmonically pumped Schottky diode mixers offer a number of advantages for array implementation in a heterodyne receiver system. Since the radio frequency (RF) and local oscillator (LO) signals are far apart, system design becomes much simpler. A proprietary planar GaAs Schottky diode process was developed that results in very low parasitic anodes that have cutoff frequencies in the tens of terahertz. This technology enables robust implementation of monolithic mixer and frequency multiplier circuits well into the terahertz frequency range. Using optical and e-beam lithography, and conventional epitaxial layer design with innovative usage of GaAs membranes and metal beam leads, high-performance terahertz circuits can be designed with high fidelity. All of these mixers use metal waveguide structures for housing. Metal machined structures for RF and LO coupling hamper these mixers to be integrated in multi-pixel heterodyne array receivers for spectroscopic and imaging applications. Moreover, the recent developments of terahertz transistors on InP substrate provide an opportunity, for the first time, to have integrated amplifiers followed by Schottky diode mixers in a heterodyne receiver at these frequencies. Since the amplifiers are developed on a planar architecture to facilitate multi-pixel array implementation, it is quite important to find alternative architecture to waveguide-based mixers.

  12. Neuromimetic Circuits with Synaptic Devices Based on Strongly Correlated Electron Systems

    NASA Astrophysics Data System (ADS)

    Ha, Sieu D.; Shi, Jian; Meroz, Yasmine; Mahadevan, L.; Ramanathan, Shriram

    2014-12-01

    Strongly correlated electron systems such as the rare-earth nickelates (R NiO3 , R denotes a rare-earth element) can exhibit synapselike continuous long-term potentiation and depression when gated with ionic liquids; exploiting the extreme sensitivity of coupled charge, spin, orbital, and lattice degrees of freedom to stoichiometry. We present experimental real-time, device-level classical conditioning and unlearning using nickelate-based synaptic devices in an electronic circuit compatible with both excitatory and inhibitory neurons. We establish a physical model for the device behavior based on electric-field-driven coupled ionic-electronic diffusion that can be utilized for design of more complex systems. We use the model to simulate a variety of associate and nonassociative learning mechanisms, as well as a feedforward recurrent network for storing memory. Our circuit intuitively parallels biological neural architectures, and it can be readily generalized to other forms of cellular learning and extinction. The simulation of neural function with electronic device analogs may provide insight into biological processes such as decision making, learning, and adaptation, while facilitating advanced parallel information processing in hardware.

  13. Leaky Integrate-and-Fire Neuron Circuit Based on Floating-Gate Integrator.

    PubMed

    Kornijcuk, Vladimir; Lim, Hyungkwang; Seok, Jun Yeong; Kim, Guhyun; Kim, Seong Keun; Kim, Inho; Choi, Byung Joon; Jeong, Doo Seok

    2016-01-01

    The artificial spiking neural network (SNN) is promising and has been brought to the notice of the theoretical neuroscience and neuromorphic engineering research communities. In this light, we propose a new type of artificial spiking neuron based on leaky integrate-and-fire (LIF) behavior. A distinctive feature of the proposed FG-LIF neuron is the use of a floating-gate (FG) integrator rather than a capacitor-based one. The relaxation time of the charge on the FG relies mainly on the tunnel barrier profile, e.g., barrier height and thickness (rather than the area). This opens up the possibility of large-scale integration of neurons. The circuit simulation results offered biologically plausible spiking activity (<100 Hz) with a capacitor of merely 6 fF, which is hosted in an FG metal-oxide-semiconductor field-effect transistor. The FG-LIF neuron also has the advantage of low operation power (<30 pW/spike). Finally, the proposed circuit was subject to possible types of noise, e.g., thermal noise and burst noise. The simulation results indicated remarkable distributional features of interspike intervals that are fitted to Gamma distribution functions, similar to biological neurons in the neocortex. PMID:27242416

  14. The Circuit Theory Behind Coupled-Mode Magnetic Resonance-Based Wireless Power Transmission

    PubMed Central

    Kiani, Mehdi; Ghovanloo, Maysam

    2014-01-01

    Inductive coupling is a viable scheme to wirelessly energize devices with a wide range of power requirements from nanowatts in radio frequency identification tags to milliwatts in implantable microelectronic devices, watts in mobile electronics, and kilowatts in electric cars. Several analytical methods for estimating the power transfer efficiency (PTE) across inductive power transmission links have been devised based on circuit and electromagnetic theories by electrical engineers and physicists, respectively. However, a direct side-by-side comparison between these two approaches is lacking. Here, we have analyzed the PTE of a pair of capacitively loaded inductors via reflected load theory (RLT) and compared it with a method known as coupled-mode theory (CMT). We have also derived PTE equations for multiple capacitively loaded inductors based on both RLT and CMT. We have proven that both methods basically result in the same set of equations in steady state and either method can be applied for short- or midrange coupling conditions. We have verified the accuracy of both methods through measurements, and also analyzed the transient response of a pair of capacitively loaded inductors. Our analysis shows that the CMT is only applicable to coils with high quality factor (Q) and large coupling distance. It simplifies the analysis by reducing the order of the differential equations by half compared to the circuit theory. PMID:24683368

  15. The Circuit Theory Behind Coupled-Mode Magnetic Resonance-Based Wireless Power Transmission.

    PubMed

    Kiani, Mehdi; Ghovanloo, Maysam

    2012-09-01

    Inductive coupling is a viable scheme to wirelessly energize devices with a wide range of power requirements from nanowatts in radio frequency identification tags to milliwatts in implantable microelectronic devices, watts in mobile electronics, and kilowatts in electric cars. Several analytical methods for estimating the power transfer efficiency (PTE) across inductive power transmission links have been devised based on circuit and electromagnetic theories by electrical engineers and physicists, respectively. However, a direct side-by-side comparison between these two approaches is lacking. Here, we have analyzed the PTE of a pair of capacitively loaded inductors via reflected load theory (RLT) and compared it with a method known as coupled-mode theory (CMT). We have also derived PTE equations for multiple capacitively loaded inductors based on both RLT and CMT. We have proven that both methods basically result in the same set of equations in steady state and either method can be applied for short- or midrange coupling conditions. We have verified the accuracy of both methods through measurements, and also analyzed the transient response of a pair of capacitively loaded inductors. Our analysis shows that the CMT is only applicable to coils with high quality factor (Q) and large coupling distance. It simplifies the analysis by reducing the order of the differential equations by half compared to the circuit theory. PMID:24683368

  16. Leaky Integrate-and-Fire Neuron Circuit Based on Floating-Gate Integrator

    PubMed Central

    Kornijcuk, Vladimir; Lim, Hyungkwang; Seok, Jun Yeong; Kim, Guhyun; Kim, Seong Keun; Kim, Inho; Choi, Byung Joon; Jeong, Doo Seok

    2016-01-01

    The artificial spiking neural network (SNN) is promising and has been brought to the notice of the theoretical neuroscience and neuromorphic engineering research communities. In this light, we propose a new type of artificial spiking neuron based on leaky integrate-and-fire (LIF) behavior. A distinctive feature of the proposed FG-LIF neuron is the use of a floating-gate (FG) integrator rather than a capacitor-based one. The relaxation time of the charge on the FG relies mainly on the tunnel barrier profile, e.g., barrier height and thickness (rather than the area). This opens up the possibility of large-scale integration of neurons. The circuit simulation results offered biologically plausible spiking activity (<100 Hz) with a capacitor of merely 6 fF, which is hosted in an FG metal-oxide-semiconductor field-effect transistor. The FG-LIF neuron also has the advantage of low operation power (<30 pW/spike). Finally, the proposed circuit was subject to possible types of noise, e.g., thermal noise and burst noise. The simulation results indicated remarkable distributional features of interspike intervals that are fitted to Gamma distribution functions, similar to biological neurons in the neocortex. PMID:27242416

  17. Approximate circuits for increased reliability

    DOEpatents

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-12-22

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  18. Approximate circuits for increased reliability

    DOEpatents

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-08-18

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  19. Surface-charge accumulation effects on open-circuit voltage in organic solar cells based on photoinduced impedance analysis.

    PubMed

    Zang, Huidong; Hsiao, Yu-Che; Hu, Bin

    2014-03-14

    The accumulation of dissociated charge carriers plays an important role in reducing the loss occurring in organic solar cells. We find from light-assisted capacitance measurements that the charge accumulation inevitably occurred at the electrode and photovoltaic layer interface for bulk-heterojunction ITO/PEDOT:PSS/P3HT:PCBM/Ca/Al solar cells. Our results indicate, for the first time through impedance measurements, that the charge accumulation exists at the anode side of the device, and more importantly, we successfully identify the type of charge accumulated. Further study shows that the charge accumulation can significantly affect open circuit voltage and short circuit current. As a result, our experimental results from light assisted capacitance measurements provide a new understanding of the loss in open-circuit voltage and short-circuit photocurrent based on charge accumulation. Clearly, controlling charge accumulation presents a new mechanism to improve the photovoltaic performance of organic solar cells.

  20. Ribozyme-based insulator parts buffer synthetic circuits from genetic context

    PubMed Central

    Lou, Chunbo; Stanton, Brynne; Chen, Ying-Ja; Munsky, Brian; Voigt, Christopher A

    2014-01-01

    Synthetic genetic programs are built from circuits that integrate sensors and implement temporal control of gene expression1–4. Transcriptional circuits are layered by using promoters to carry the signal between circuits. In other words, the output promoter of one circuit serves as the input promoter to the next. Thus, connecting circuits requires physically connecting a promoter to the next circuit. We show that the sequence at the junction between the input promoter and circuit can affect the input-output response (transfer function) of the circuit5–9. A library of putative sequences that might reduce (or buffer) such context effects, which we refer to as ‘insulator parts’, is screened in Escherichia coli. We find that ribozymes that cleave the 5′ untranslated region (5′-UTR) of the mRNA are effective insulators. They generate quantitatively identical transfer functions, irrespective of the identity of the input promoter. When these insulators are used to join synthetic gene circuits, the behavior of layered circuits can be predicted using a mathematical model. The inclusion of insulators will be critical in reliably permuting circuits to build different programs. PMID:23034349

  1. A survey of mathematics-based equivalent-circuit and electrochemical battery models for hybrid and electric vehicle simulation

    NASA Astrophysics Data System (ADS)

    Seaman, Aden; Dao, Thanh-Son; McPhee, John

    2014-06-01

    In this paper, we survey two kinds of mathematics-based battery models intended for use in hybrid and electric vehicle simulation. The first is circuit-based, which is founded upon the electrical behaviour of the battery, and abstracts away the electrochemistry into equivalent electrical components. The second is chemistry-based, which is founded upon the electrochemical equations of the battery chemistry.

  2. Measuring circuit

    DOEpatents

    Sun, Shan C.; Chaprnka, Anthony G.

    1977-01-11

    An automatic gain control circuit functions to adjust the magnitude of an input signal supplied to a measuring circuit to a level within the dynamic range of the measuring circuit while a log-ratio circuit adjusts the magnitude of the output signal from the measuring circuit to the level of the input signal and optimizes the signal-to-noise ratio performance of the measuring circuit.

  3. High Open-Circuit Voltage Solar Cells Based on Organic-Inorganic Lead Bromide Perovskite.

    PubMed

    Edri, Eran; Kirmayer, Saar; Cahen, David; Hodes, Gary

    2013-03-21

    Mesoscopic solar cells, based on solution-processed organic-inorganic perovskite absorbers, are a promising avenue for converting solar to electrical energy. We used solution-processed organic-inorganic lead halide perovskite absorbers, in conjunction with organic hole conductors, to form high voltage solar cells. There is a dire need for low-cost cells of this type, to drive electrochemical reactions or as the high photon energy cell in a system with spectral splitting. These perovskite materials, although spin-coated from solution, form highly crystalline materials. Their simple synthesis, along with high chemical versatility, allows tuning their electronic and optical properties. By judicious selection of the perovskite lead halide-based absorber, matching organic hole conductor, and contacts, a cell with a ∼ 1.3 V open circuit voltage was made. While further study is needed, this achievement provides a general guideline for additional improvement of cell performance.

  4. A compact ADPLL based on symmetrical binary frequency searching with the same circuit

    NASA Astrophysics Data System (ADS)

    Li, Hangbiao; Zhang, Bo; Luo, Ping; Liao, Pengfei; Liu, Junjie; Li, Zhaoji

    2015-03-01

    A compact all-digital phase-locked loop (C-ADPLL) based on symmetrical binary frequency searching (BFS) with the same circuit is presented in this paper. The minimising relative frequency variation error Δη (MFE) rule is derived as guidance of design and is used to weigh the accuracy of the digitally controlled oscillator (DCO) clock frequency. The symmetrical BFS is used in the coarse-tuning process and the fine-tuning process of DCO clock frequency to achieve the minimum Δη of the locked DCO clock, which simplifies the circuit architecture and saves the die area. The C-ADPLL is implemented in a 0.13 μm one-poly-eight-metal (1P8M) CMOS process and the on-chip area is only 0.043 mm2, which is much smaller. The measurement results show that the peak-to-peak (Pk-Pk) jitter and the root-mean-square jitter of the DCO clock frequency are 270 ps at 72.3 MHz and 42 ps at 79.4 MHz, respectively, while the power consumption of the proposed ADPLL is only 2.7 mW (at 115.8 MHz) with a 1.2 V power supply. The measured Δη is not more than 1.14%. Compared with other ADPLLs, the proposed C-ADPLL has simpler architecture, smaller size and lower Pk-Pk jitter.

  5. Deterministic Integration of Single Photon Sources in Silicon Based Photonic Circuits.

    PubMed

    Zadeh, Iman Esmaeil; Elshaari, Ali W; Jöns, Klaus D; Fognini, Andreas; Dalacu, Dan; Poole, Philip J; Reimer, Michael E; Zwiller, Val

    2016-04-13

    A major step toward fully integrated quantum optics is the deterministic incorporation of high quality single photon sources in on-chip optical circuits. We show a novel hybrid approach in which preselected III-V single quantum dots in nanowires are transferred and integrated in silicon based photonic circuits. The quantum emitters maintain their high optical quality after integration as verified by measuring a low multiphoton probability of 0.07 ± 0.07 and emission line width as narrow as 3.45 ± 0.48 GHz. Our approach allows for optimum alignment of the quantum dot light emission to the fundamental waveguide mode resulting in very high coupling efficiencies. We estimate a coupling efficiency of 24.3 ± 1.7% from the studied single-photon source to the photonic channel and further show by finite-difference time-domain simulations that for an optimized choice of material and design the efficiency can exceed 90%. PMID:26954298

  6. Novel system for automatic measuring diopter based on ARM circuit block

    NASA Astrophysics Data System (ADS)

    Xue, Feng; Zhong, Lei; Chen, Zhe; Xue, Deng-pan; Li, Xiang-ning

    2009-07-01

    Traditional commercial instruments utilized in vision screening programs cannot satisfy the request for real-time diopter measurement by far, and their success is limited by some defectiveness such as computer-attached, clumsy volume, and low accuracy of parameters measured, etc. In addition, astigmatic eyes cannot be determined in many devices. This paper proposes a new design of diopter measurement system based on SAMSUNG's ARM9 circuit block. There are several contributions in the design. The new developed system has not only the function of automatically measuring diopter, but also the advantages of the low cost, and especially the simplicity and portability. Besides, by placing point sources in three directions, the instrument can determine astigmatic eyes at the same time. Most of the details are introduced as the integrated design of measuring system, interface circuit of embedded system and so on. Through a preliminary experiment, it is proved that the system keeps good feasibility and validity. The maximum deviation of measurement result is 0.344D.The experimental results also demonstrate the system can provide the service needed for real-time applications. The instrument present here is expected to be widely applied in many fields such as the clinic and home healthcare.

  7. Atomic-Based-Combined-Cycle Analysis

    NASA Technical Reports Server (NTRS)

    Han, Samuel S.

    1999-01-01

    Atomic-based-combined-cycle (ABCC) engine combines an air-breathing ramjet engine with an atomic reactor to increase the mission-averaged specific impulse and thereby increasing the dry-mass ratio. ABCC engine is similar to RBCC engine except that energy needed for the propulsive power is derived from nuclear reaction rather than chemical combustion used in the RBCC engine. The potential performance improvement of an ABCC engine over a RBCC engine comes from two factors. Firstly, the energy density of nuclear reaction is several order of magnitudes higher than the chemical combustion. Secondly, hydrogen can produce much higher nozzle exit velocity because of its small molecular weight. A one-dimensional, transient numerical model was used to analyze a generic RBCC engine and it is used as a baseline to evaluate an imaginary ABCC engine performance. A nuclear reactor is treated as a black box energy source that replaces the role of the primary rocket and the chemical combustion chamber in a RBCC engine. The performance of a generic ABCC engine along a flight path (q0 =10 (exp 3) lbf per square ft) shows that the mission averaged-specific impulse is about twice larger than RBCC engine and the dry mass-ratio is about 50% larger. Results of the present ABCC engine performance are based on the assumptions that the flow passage of working fluids is identical to that of RBCC engine and that a nuclear reactor is treated as an energy black box. Preliminary heat transfer calculation shows that the rate of heat transfer to the working fluids is within the limit of turbulent convective heat transfer regimes. The flow passage of realistic ABCC engine must be known for a better prediction of ABCC engine performance. Also, critical heat transfer calculations must be performed for the ejector mode and ramjet mode operations. This is possible only when the details of a reactor configuration are available.

  8. Design, development and evaluation of a resistor-based multiplexing circuit for a 20×20 SiPM array

    NASA Astrophysics Data System (ADS)

    Wang, Zhonghai; Sun, Xishan; Lou, Kai; Meier, Joseph; Zhou, Rong; Yang, Chaowen; Zhu, Xiaorong; Shao, Yiping

    2016-04-01

    One technical challenge in developing a large-size scintillator detector with multiple Silicon Photomultiplier (SiPM) arrays is to read out a large number of detector output channels. To achieve this, different signal multiplexing circuits have been studied and applied with different performances and cost-effective tradeoffs. Resistor-based multiplexing circuits exhibit simplicity and signal integrity, but also present the disadvantage of timing shift among different channels. In this study, a resistor-based multiplexing circuit for a large-sized SiPM array readout was developed and evaluated by simulation and experimental studies. Similarly to a multiplexing circuit used for multi-anode PMT, grounding and branching resistors were connected to each SiPM output channel. The grounding resistor was used to simultaneously reduce the signal crosstalk among different channels and to improve timing performance. Both grounding and branching resistor values were optimized to maintain a balanced performance of the event energy, timing, and positioning. A multiplexing circuit was implemented on a compact PCB and applied for a flat-panel detector which consisted of a 32×32 LYSO scintillator crystals optically coupled to 5×5 SiPM arrays for a total 20×20 output channels. Test results showed excellent crystal identification for all 1024 LYSO crystals (each with 2×2×30 mm3 size) with 22Na flood-source irradiation. The measured peak-to-valley ratio from typical crystal map profile is around 3:1 to 6.6:1, an average single crystal energy resolution of about 17.3%, and an average single crystal timing resolution of about 2 ns. Timing shift among different crystals, as reported in some other resistor-based multiplexing circuit designs, was not observed. In summary, we have designed and implemented a practical resistor-based multiplexing circuit that can be readily applied for reading out a large SiPM array with good detector performance.

  9. Silicon-on-insulator-based high-voltage, high-temperature integrated circuit gate driver for silicon carbide-based power field effect transistors

    SciTech Connect

    Tolbert, Leon M; Huque, Mohammad A; Blalock, Benjamin J; Islam, Syed K

    2010-01-01

    Silicon carbide (SiC)-based field effect transistors (FETs) are gaining popularity as switching elements in power electronic circuits designed for high-temperature environments like hybrid electric vehicle, aircraft, well logging, geothermal power generation etc. Like any other power switches, SiC-based power devices also need gate driver circuits to interface them with the logic units. The placement of the gate driver circuit next to the power switch is optimal for minimising system complexity. Successful operation of the gate driver circuit in a harsh environment, especially with minimal or no heat sink and without liquid cooling, can increase the power-to-volume ratio as well as the power-to-weight ratio for power conversion modules such as a DC-DC converter, inverter etc. A silicon-on-insulator (SOI)-based high-voltage, high-temperature integrated circuit (IC) gate driver for SiC power FETs has been designed and fabricated using a commercially available 0.8--m, 2-poly and 3-metal bipolar-complementary metal oxide semiconductor (CMOS)-double diffused metal oxide semiconductor (DMOS) process. The prototype circuit-s maximum gate drive supply can be 40-V with peak 2.3-A sourcing/sinking current driving capability. Owing to the wide driving range, this gate driver IC can be used to drive a wide variety of SiC FET switches (both normally OFF metal oxide semiconductor field effect transistor (MOSFET) and normally ON junction field effect transistor (JFET)). The switching frequency is 20-kHz and the duty cycle can be varied from 0 to 100-. The circuit has been successfully tested with SiC power MOSFETs and JFETs without any heat sink and cooling mechanism. During these tests, SiC switches were kept at room temperature and ambient temperature of the driver circuit was increased to 200-C. The circuit underwent numerous temperature cycles with negligible performance degradation.

  10. Atomic-Based-Combined-Cycle Analysis

    NASA Technical Reports Server (NTRS)

    Han, Sam; Bai, Don; Schmidt, George

    2000-01-01

    Atomic-based-combined-cycle (ABCC) engine combines an air-breathing ramjet engine with an atomic reactor to increase the mission-averaged specific impulse and thereby increasing the dry-mass ratio. ABCC engine is similar to RBCC engine except that energy needed for the propulsive power is derived from nuclear reaction rather than chemical combustion used in the RBCC engine. The potential performance improvement of an ABCC engine over a RBCC engine comes from two factors. Firstly, the energy density of nuclear reaction is several order of magnitudes higher than the chemical combustion. Secondly, hydrogen can produce much higher nozzle exit velocity because of its small molecular weight. A one-dimensional, transient numerical model was used to analyze a generic scramjet engine and it is used as a baseline to evaluate an imaginary ABCC engine performance. A nuclear reactor is treated as a black box energy source that replaces the role of the primary rocket and the chemical combustion chamber in a RBCC engine. Hydrogen is heated by the reactor and accelerated to produce high-speed ejection velocity. The ejection velocity up 10,000 m/sec is theoretically possible because of high energy density from the reactor and large gas constant of the hydrogen. Oxygen contained in the entrained air reacts with hydrogen and produces propulsive power for ejector mode operation. To provide enough thrust for initial acceleration, relatively large amount of hydrogen must be pumped through the reactor. Amount of oxygen contained in the entrained air may not be sufficient to burn all hydrogen and consequently combustion could occur at the end of exit nozzle. It is assumed that this combustion process is constant-pressure combustion at 1.0 atmospheric pressure and thus not affects the nozzle exit condition.

  11. Graphene-based tunable non-foster circuit for VHF applications

    NASA Astrophysics Data System (ADS)

    Tian, Jing; Nagarkoti, Deepak Singh; Rajab, Khalid Z.; Hao, Yang

    2016-06-01

    This paper presents a negative impedance converter (NIC) based on graphene field effect transistors (GFETs) for VHF applications. The NIC is designed following Linvill's open circuit stable (OCS) topology. The DC modelling parameters of GFET are extracted from a device measured by Meric et al. [IEEE Electron Devices Meeting, 23.2.1 (2010)] Estimated parasitics are also taken into account. Simulation results from Keysight Advanced Design System (ADS) show good NIC performance up to 200 MHz and the value of negative capacitance is directly proportional to the capacitive load. In addition, it has been shown that by varying the supply voltage the value of negative capacitance can also be tuned. The NIC stability has been tested up to 2 GHz (10 times the maximum operation frequency) using Nyquist stability criterion to ensure there are no oscillation issues.

  12. Electro-optic directed XOR logic circuits based on parallel-cascaded micro-ring resonators.

    PubMed

    Tian, Yonghui; Zhao, Yongpeng; Chen, Wenjie; Guo, Anqi; Li, Dezhao; Zhao, Guolin; Liu, Zilong; Xiao, Huifu; Liu, Guipeng; Yang, Jianhong

    2015-10-01

    We report an electro-optic photonic integrated circuit which can perform the exclusive (XOR) logic operation based on two silicon parallel-cascaded microring resonators (MRRs) fabricated on the silicon-on-insulator (SOI) platform. PIN diodes embedded around MRRs are employed to achieve the carrier injection modulation. Two electrical pulse sequences regarded as two operands of operations are applied to PIN diodes to modulate two MRRs through the free carrier dispersion effect. The final operation result of two operands is output at the Output port in the form of light. The scattering matrix method is employed to establish numerical model of the device, and numerical simulator SG-framework is used to simulate the electrical characteristics of the PIN diodes. XOR operation with the speed of 100Mbps is demonstrated successfully.

  13. A Novel Picosecond Pulse Generation Circuit Based on SRD and NLTL

    PubMed Central

    Zhou, Jianming; Lu, Qiuyuan; Liu, Fan; Li, Yinqiao

    2016-01-01

    Because of the importance of ultra-wideband (UWB) radar in various applications, short pulse generation in UWB systems has attracted a lot of attention in recent years. In order to shorten the pulse, nonlinear transmission line (NLTL) is imported, which expands the application of step recovery diode (SRD) for pulse generation. Detailed analysis and equations for this SRD and NLTL-based pulse generation are provided and verified by simulation and experimental results. Factors that could cause pulse waveform distortions are also analyzed. The generator circuit presented in this paper generates 130ps and 3.3V pulse, which can be used in UWB radar systems that require sub-nanosecond pulses. PMID:26919290

  14. Investigating the role of model-based reasoning while troubleshooting an electric circuit

    NASA Astrophysics Data System (ADS)

    Dounas-Frazer, Dimitri R.; Van De Bogart, Kevin L.; Stetzer, MacKenzie R.; Lewandowski, H. J.

    2016-06-01

    We explore the overlap of two nationally recognized learning outcomes for physics lab courses, namely, the ability to model experimental systems and the ability to troubleshoot a malfunctioning apparatus. Modeling and troubleshooting are both nonlinear, recursive processes that involve using models to inform revisions to an apparatus. To probe the overlap of modeling and troubleshooting, we collected audiovisual data from think-aloud activities in which eight pairs of students from two institutions attempted to diagnose and repair a malfunctioning electrical circuit. We characterize the cognitive tasks and model-based reasoning that students employed during this activity. In doing so, we demonstrate that troubleshooting engages students in the core scientific practice of modeling.

  15. Open access to technology platforms for InP-based photonic integrated circuits

    NASA Astrophysics Data System (ADS)

    Ławniczuk, Katarzyna; Augustin, Luc M.; Grote, Norbert; Wale, Michael J.; Smit, Meint K.; Williams, Kevin A.

    2015-04-01

    Open access to generic technology platforms for photonic integrated circuit manufacturing enables low-cost development of application-specific photonic chips for novel or improved products. It brings photonic ICs within reach for many industrial users and research institutes, by moving toward a fabless business model. In the current status, InP-based open access manufacturing services are offered through multi-project wafer runs by Fraunhofer Heinrich Hertz Institut, SMART Photonics, and Oclaro. In this paper, we review state-of-the-art InP photonic integration technology platforms, present examples of complex InP photonic ICs developed in the generic technologies, and give a prospect for further development of these photonic integration platforms.

  16. A Case Study Analysing the Process of Analogy-Based Learning in a Teaching Unit about Simple Electric Circuits

    ERIC Educational Resources Information Center

    Paatz, Roland; Ryder, James; Schwedes, Hannelore; Scott, Philip

    2004-01-01

    The purpose of this case study is to analyse the learning processes of a 16-year-old student as she learns about simple electric circuits in response to an analogy-based teaching sequence. Analogical thinking processes are modelled by a sequence of four steps according to Gentner's structure mapping theory (activate base domain, postulate local…

  17. Energy and Timing Measurement with Time-Based Detector Readout for PET Applications: Principle and Validation with Discrete Circuit Components.

    PubMed

    Sun, Xishan; Lan, Allan K; Bircher, Chad; Deng, Zhi; Liu, Yinong; Shao, Yiping

    2011-06-11

    A new signal processing method for PET application has been developed, with discrete circuit components to measure energy and timing of a gamma interaction based solely on digital timing processing without using an amplitude-to-digital convertor (ADC) or a constant fraction discriminator (CFD). A single channel discrete component time-based readout (TBR) circuit was implemented in a PC board. Initial circuit functionality and performance evaluations have been conducted. Accuracy and linearity of signal amplitude measurement were excellent, as measured with test pulses. The measured timing accuracy from test pulses reached to less than 300 ps, a value limited mainly by the timing jitter of the prototype electronics circuit. Both suitable energy and coincidence timing resolutions (~18% and ~1.0 ns) have been achieved with 3 × 3 × 20 mm(3) LYSO scintillator and photomultiplier tube-based detectors. With its relatively simple circuit and low cost, TBR is expected to be a suitable front-end signal readout electronics for compact PET or other radiation detectors requiring the reading of a large number of detector channels and demanding high performance for energy and timing measurement.

  18. An instrumentation amplifier based readout circuit for a dual element microbolometer infrared detector

    NASA Astrophysics Data System (ADS)

    de Waal, D. J.; Schoeman, J.

    2014-06-01

    The infrared band is widely used in many applications to solve problems stretching over very diverse fields, ranging from medical applications like inflammation detection to military, security and safety applications employing thermal imaging in low light conditions. At the heart of these optoelectrical systems lies a sensor used to detect incident infrared radiation, and in the case of this work our focus is on uncooled microbolometers as thermal detectors. Microbolometer based thermal detectors are limited in sensitivity by various parameters, including the detector layout and design, operating temperature, air pressure and biasing that causes self heating. Traditional microbolometers use the entire membrane surface for a single detector material. This work presents the design of a readout circuit amplifier where a dual detector element microbolometer is used, rather than the traditional single element. The concept to be investigated is based on the principle that both elements will be stimulated with a similar incoming IR signal and experience the same resistive change, thus creating a common mode signal. However, such a common mode signal will be rejected by a differential amplifier, thus one element is placed within a negative resistance converter to create a differential mode signal that is twice the magnitude of the comparable single mode signal of traditional detector designs. An instrumentation amplifier is used for the final stage of the readout amplifier circuit, as it allows for very high common mode rejection with proper trimming of the Wheatstone bridge to compensate for manufacturing tolerance. It was found that by implementing the above, improved sensitivity can be achieved.

  19. A Vibration-Based MEMS Piezoelectric Energy Harvester and Power Conditioning Circuit

    PubMed Central

    Yu, Hua; Zhou, Jielin; Deng, Licheng; Wen, Zhiyu

    2014-01-01

    This paper presents a micro-electro-mechanical system (MEMS) piezoelectric power generator array for vibration energy harvesting. A complete design flow of the vibration-based energy harvester using the finite element method (FEM) is proposed. The modal analysis is selected to calculate the resonant frequency of the harvester, and harmonic analysis is performed to investigate the influence of the geometric parameters on the output voltage. Based on simulation results, a MEMS Pb(Zr,Ti)O3 (PZT) cantilever array with an integrated large Si proof mass is designed and fabricated to improve output voltage and power. Test results show that the fabricated generator, with five cantilever beams (with unit dimensions of about 3 × 2.4 × 0.05 mm3) and an individual integrated Si mass dimension of about 8 × 12.4 × 0.5 mm3, produces a output power of 66.75 μW, or a power density of 5.19 μW·mm−3·g−2 with an optimal resistive load of 220 kΩ from 5 m/s2 vibration acceleration at its resonant frequency of 234.5 Hz. In view of high internal impedance characteristic of the PZT generator, an efficient autonomous power conditioning circuit, with the function of impedance matching, energy storage and voltage regulation, is then presented, finding that the efficiency of the energy storage is greatly improved and up to 64.95%. The proposed self-supplied energy generator with power conditioning circuit could provide a very promising complete power supply solution for wireless sensor node loads. PMID:24556670

  20. A vibration-based MEMS piezoelectric energy harvester and power conditioning circuit.

    PubMed

    Yu, Hua; Zhou, Jielin; Deng, Licheng; Wen, Zhiyu

    2014-02-19

    This paper presents a micro-electro-mechanical system (MEMS) piezoelectric power generator array for vibration energy harvesting. A complete design flow of the vibration-based energy harvester using the finite element method (FEM) is proposed. The modal analysis is selected to calculate the resonant frequency of the harvester, and harmonic analysis is performed to investigate the influence of the geometric parameters on the output voltage. Based on simulation results, a MEMS Pb(Zr,Ti)O3 (PZT) cantilever array with an integrated large Si proof mass is designed and fabricated to improve output voltage and power. Test results show that the fabricated generator, with five cantilever beams (with unit dimensions of about 3 × 2.4 × 0.05 mm3) and an individual integrated Si mass dimension of about 8 × 12.4 × 0.5 mm3, produces a output power of 66.75 μW, or a power density of 5.19 μW∙mm-3∙g-2 with an optimal resistive load of 220 kΩ from 5 m/s2 vibration acceleration at its resonant frequency of 234.5 Hz. In view of high internal impedance characteristic of the PZT generator, an efficient autonomous power conditioning circuit, with the function of impedance matching, energy storage and voltage regulation, is then presented, finding that the efficiency of the energy storage is greatly improved and up to 64.95%. The proposed self-supplied energy generator with power conditioning circuit could provide a very promising complete power supply solution for wireless sensor node loads.

  1. A biomimetic coupled circuit based microphone array for sound source localization.

    PubMed

    Xu, Huping; Xu, Xiangyuan; Jia, Han; Guan, Luyang; Bao, Ming

    2015-09-01

    An equivalent analog circuit is designed to mimic the coupled ears of the fly Ormia ochracea for sound source localization. This coupled circuit receives two signals with tiny phase difference from a space closed two-microphone array, and produces two signals with obvious intensity difference. The response sensitivity can be adjusted through the coupled circuit parameters. The directional characteristics of the coupled circuit have been demonstrated in the experiment. The miniature microphone array can localize the sound source with low computational burden by using the intensity difference. This system has significant advantages in various applications where the array size is limited. PMID:26428825

  2. A biomimetic coupled circuit based microphone array for sound source localization.

    PubMed

    Xu, Huping; Xu, Xiangyuan; Jia, Han; Guan, Luyang; Bao, Ming

    2015-09-01

    An equivalent analog circuit is designed to mimic the coupled ears of the fly Ormia ochracea for sound source localization. This coupled circuit receives two signals with tiny phase difference from a space closed two-microphone array, and produces two signals with obvious intensity difference. The response sensitivity can be adjusted through the coupled circuit parameters. The directional characteristics of the coupled circuit have been demonstrated in the experiment. The miniature microphone array can localize the sound source with low computational burden by using the intensity difference. This system has significant advantages in various applications where the array size is limited.

  3. Si-based light emitter in an integrated photonic circuit for smart biosensor applications

    NASA Astrophysics Data System (ADS)

    Germer, S.; Cherkouk, C.; Rebohle, L.; Helm, M.; Skorupa, W.

    2013-05-01

    The motivation for integrated Silicon-based optoelectronics is the creation of low-cost photonics for mass-market applications. Especially, the growing demand for sensitive biochemical sensors in the environmental control or medicine leads to the development of integrated high resolution sensors. Here we present initial results in the integration and butt-coupling of a Si-based light emitting device (LED) [1-3] to a waveguide into a photonic circuit. Our first approach deals with the design, fabrication and characterization of the dielectric high contrast waveguide as an important component, beside the LED, for the development of a Si-based biodetection system. In this work we demonstrate design examples of Si3N4/SiO2-waveguides, which were calculated using MATLAB, the effective index method (EIM) and the finite element method (FEM), with a 0.45μm thick and 0.7μm wide core which shows a high confinement factor of ~74% and coupling efficiency of ~66% at 1.55μm, respectively. The fabrication was done by plasma enhanced chemical vapour deposition (PECVD), optical lithography and reactive ion etching (RIE). Additionally, we characterized the deposited layers via ellipsometry and the etched structures by scanning electron microscopy (SEM). The obtained results establish principles for Si-based LED butt-coupling to a powerful optical waveguide-based interconnect with effective light absorption and an adequate coupling efficiency.

  4. Heterostructure-based high-speed/high-frequency electronic circuit applications

    NASA Astrophysics Data System (ADS)

    Zampardi, P. J.; Runge, K.; Pierson, R. L.; Higgins, J. A.; Yu, R.; McDermott, B. T.; Pan, N.

    1999-08-01

    With the growth of wireless and lightwave technologies, heterostructure electronic devices are commodity items in the commercial marketplace [Browne J. Power-amplifier MMICs drive commercial circuits. Microwaves & RF, 1998. p. 116-24.]. In particular, HBTs are an attractive device for handset power amplifiers at 900 MHz and 1.9 GHz for CDMA applications [Lum E. GaAs technology rides the wireless wave. Proceedings of the 1997 GaAs IC Symposium, 1997. p. 11-13; "Rockwell Ramps Up". Compound Semiconductor, May/June 1997.]. At higher frequencies, both HBTs and p-HEMTs are expected to dominate the marketplace. For high-speed lightwave circuit applications, heterostructure based products on the market for OC-48 (2.5 Gb/s) and OC-192 (10 Gb/s) are emerging [http://www.nb.rockwell.com/platforms/network_access/nahome.html#5.; http://www.nortel.com/technology/opto/receivers/ptav2.html.]. Chips that operate at 40 Gb/ have been demonstrated in a number of research laboratories [Zampardi PJ, Pierson RL, Runge K, Yu R, Beccue SM, Yu J, Wang KC. hybrid digital/microwave HBTs for >30 Gb/s optical communications. IEDM Technical Digest, 1995. p. 803-6; Swahn T, Lewin T, Mokhtari M, Tenhunen H, Walden R, Stanchina W. 40 Gb/s 3 Volt InP HBT ICs for a fiber optic demonstrator system. Proceedings of the 1996 GaAs IC Symposium, 1996. p. 125-8; Suzuki H, Watanabe K, Ishikawa K, Masuda H, Ouchi K, Tanoue T, Takeyari R. InP/InGaAs HBT ICs for 40 Gbit/s optical transmission systems. Proceedings of the 1997 GaAs IC Symposium, 1997. p. 215-8]. In addition to these two markets, another area where heterostructure devices are having significant impact is for data conversion [Walden RH. Analog-to digital convertor technology comparison. Proceedings of the 1994 GaAs IC Symposium, 1994. p. 217-9; Poulton K, Knudsen K, Corcoran J, Wang KC, Nubling RB, Chang M-CF, Asbeck PM, Huang RT. A 6-b, 4 GSa/s GaAs HBT ADC. IEEE J Solid-State Circuits 1995;30:1109-18; Nary K, Nubling R, Beccue S, Colleran W

  5. Genetically encoded optical indicators for the analysis of neuronal circuits.

    PubMed

    Knöpfel, Thomas

    2012-10-01

    In a departure from previous top-down or bottom-up strategies used to understand neuronal circuits, many forward-looking research programs now place the circuit itself at their centre. This has led to an emphasis on the dissection and elucidation of neuronal circuit elements and mechanisms, and on studies that ask how these circuits generate behavioural outputs. This movement towards circuit-centric strategies is progressing rapidly as a result of technological advances that combine genetic manipulation with light-based methods. The core tools of these new approaches are genetically encoded optical indicators and actuators that enable non-destructive interrogation and manipulation of neuronal circuits in behaving animals with cellular-level precision. This Review examines genetically encoded reporters of neuronal function and assesses their value for circuit-oriented neuroscientific investigations.

  6. Driver circuit

    NASA Technical Reports Server (NTRS)

    Matsumoto, Raymond T. (Inventor); Higashi, Stanley T. (Inventor)

    1976-01-01

    A driver circuit which has low power requirements, a relatively small number of components and provides flexibility in output voltage setting. The driver circuit comprises, essentially, two portions which are selectively activated by the application of input signals. The output signal is determined by which of the two circuit portions is activated. While each of the two circuit portions operates in a manner similar to silicon controlled rectifiers (SCR), the circuit portions are on only when an input signal is supplied thereto.

  7. Toward printed integrated circuits based on unipolar or ambipolar polymer semiconductors.

    PubMed

    Baeg, Kang-Jun; Caironi, Mario; Noh, Yong-Young

    2013-08-21

    For at least the past ten years printed electronics has promised to revolutionize our daily life by making cost-effective electronic circuits and sensors available through mass production techniques, for their ubiquitous applications in wearable components, rollable and conformable devices, and point-of-care applications. While passive components, such as conductors, resistors and capacitors, had already been fabricated by printing techniques at industrial scale, printing processes have been struggling to meet the requirements for mass-produced electronics and optoelectronics applications despite their great potential. In the case of logic integrated circuits (ICs), which constitute the focus of this Progress Report, the main limitations have been represented by the need of suitable functional inks, mainly high-mobility printable semiconductors and low sintering temperature conducting inks, and evoluted printing tools capable of higher resolution, registration and uniformity than needed in the conventional graphic arts printing sector. Solution-processable polymeric semiconductors are the best candidates to fulfill the requirements for printed logic ICs on flexible substrates, due to their superior processability, ease of tuning of their rheology parameters, and mechanical properties. One of the strongest limitations has been mainly represented by the low charge carrier mobility (μ) achievable with polymeric, organic field-effect transistors (OFETs). However, recently unprecedented values of μ ∼ 10 cm(2) /Vs have been achieved with solution-processed polymer based OFETs, a value competing with mobilities reported in organic single-crystals and exceeding the performances enabled by amorphous silicon (a-Si). Interestingly these values were achieved thanks to the design and synthesis of donor-acceptor copolymers, showing limited degree of order when processed in thin films and therefore fostering further studies on the reason leading to such improved charge

  8. Optodic bonding of optoelectronic components in transparent polymer substrates-based flexible circuit systems

    NASA Astrophysics Data System (ADS)

    Wang, Yixiao; Akin, Meriem; Jogschies, Lisa; Overmeyer, Ludger; Rissing, Lutz

    2015-02-01

    In the field of modern information technology, optoelectronics are being widely used, and play an increasingly important role. Meanwhile, the demand for more flexible circuit carriers is rapidly growing, since flexibility facilitates the realization of diverse functions and applications. As a potential candidate, transparent polymer substrates with a thickness of about a hundred micrometers by virtue of their low cost and sufficient flexibility are getting more attention. Thus, accomplishing an integration of optoelectronic components into polymer based flexible circuit systems increasingly is becoming an attractive research topic, which is of great significance for future information transmission and processing. We are committed to developing a new microchip bonding process to realize it. Taking into account the fact that most economical transparent polymer substrates can only be processed with restricted thermal loading, we designed a so-called optode instead of a widely adopted thermode. We employ UV-curing adhesives as bonding materials; accordingly, the optode is equipped with a UV irradiation source. An investigation of commercial optoelectronic components is conducted, in which their dimensions and structures are studied. While selecting appropriate transparent polymer substrates, we take their characteristics such as UV transmission degree, glass transition temperature, etc. as key criterions, and choose polyethylene terephthalate (PET) and polymethyl methacrylate (PMMA) as carrier materials. Besides bonding achieved through the use of adhesives cured by the optode, underfill is accordingly employed to enhance the reliability of the integration. We deposit electrical interconnects onto the polymeric substrate to be able to bring the optoelectronic components into electrical operation. In order to enlarge the optical coupling zone from component to substrate within the proximity of the adhesive or underfill, we employ transparent interconnects made of indium

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

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

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

  10. A Broadband Polyvinylidene Difluoride-Based Hydrophone with Integrated Readout Circuit for Intravascular Photoacoustic Imaging.

    PubMed

    Daeichin, Verya; Chen, Chao; Ding, Qing; Wu, Min; Beurskens, Robert; Springeling, Geert; Noothout, Emile; Verweij, Martin D; van Dongen, Koen W A; Bosch, Johan G; van der Steen, Antonius F W; de Jong, Nico; Pertijs, Michiel; van Soest, Gijs

    2016-05-01

    Intravascular photoacoustic (IVPA) imaging can visualize the coronary atherosclerotic plaque composition on the basis of the optical absorption contrast. Most of the photoacoustic (PA) energy of human coronary plaque lipids was found to lie in the frequency band between 2 and 15 MHz requiring a very broadband transducer, especially if a combination with intravascular ultrasound is desired. We have developed a broadband polyvinylidene difluoride (PVDF) transducer (0.6 × 0.6 mm, 52 μm thick) with integrated electronics to match the low capacitance of such a small polyvinylidene difluoride element (<5 pF/mm(2)) with the high capacitive load of the long cable (∼100 pF/m). The new readout circuit provides an output voltage with a sensitivity of about 3.8 μV/Pa at 2.25 MHz. Its response is flat within 10 dB in the range 2 to 15 MHz. The root mean square (rms) output noise level is 259 μV over the entire bandwidth (1-20 MHz), resulting in a minimum detectable pressure of 30 Pa at 2.25 MHz.

  11. A Broadband Polyvinylidene Difluoride-Based Hydrophone with Integrated Readout Circuit for Intravascular Photoacoustic Imaging.

    PubMed

    Daeichin, Verya; Chen, Chao; Ding, Qing; Wu, Min; Beurskens, Robert; Springeling, Geert; Noothout, Emile; Verweij, Martin D; van Dongen, Koen W A; Bosch, Johan G; van der Steen, Antonius F W; de Jong, Nico; Pertijs, Michiel; van Soest, Gijs

    2016-05-01

    Intravascular photoacoustic (IVPA) imaging can visualize the coronary atherosclerotic plaque composition on the basis of the optical absorption contrast. Most of the photoacoustic (PA) energy of human coronary plaque lipids was found to lie in the frequency band between 2 and 15 MHz requiring a very broadband transducer, especially if a combination with intravascular ultrasound is desired. We have developed a broadband polyvinylidene difluoride (PVDF) transducer (0.6 × 0.6 mm, 52 μm thick) with integrated electronics to match the low capacitance of such a small polyvinylidene difluoride element (<5 pF/mm(2)) with the high capacitive load of the long cable (∼100 pF/m). The new readout circuit provides an output voltage with a sensitivity of about 3.8 μV/Pa at 2.25 MHz. Its response is flat within 10 dB in the range 2 to 15 MHz. The root mean square (rms) output noise level is 259 μV over the entire bandwidth (1-20 MHz), resulting in a minimum detectable pressure of 30 Pa at 2.25 MHz. PMID:26856788

  12. High accuracy digital aging monitor based on PLL-VCO circuit

    NASA Astrophysics Data System (ADS)

    Yuejun, Zhang; Zhidi, Jiang; Pengjun, Wang; Xuelong, Zhang

    2015-01-01

    As the manufacturing process is scaled down to the nanoscale, the aging phenomenon significantly affects the reliability and lifetime of integrated circuits. Consequently, the precise measurement of digital CMOS aging is a key aspect of nanoscale aging tolerant circuit design. This paper proposes a high accuracy digital aging monitor using phase-locked loop and voltage-controlled oscillator (PLL-VCO) circuit. The proposed monitor eliminates the circuit self-aging effect for the characteristic of PLL, whose frequency has no relationship with circuit aging phenomenon. The PLL-VCO monitor is implemented in TSMC low power 65 nm CMOS technology, and its area occupies 303.28 × 298.94 μm2. After accelerating aging tests, the experimental results show that PLL-VCO monitor improves accuracy about high temperature by 2.4% and high voltage by 18.7%.

  13. PVC-based composite material containing recycled non-metallic printed circuit board (PCB) powders.

    PubMed

    Wang, Xinjie; Guo, Yuwen; Liu, Jingyang; Qiao, Qi; Liang, Jijun

    2010-12-01

    The study is directed to the use of non-metallic powders obtained from comminuted recycled paper-based printed circuit boards (PCBs) as an additive to polyvinyl chloride (PVC) substrate. The physical properties of the non-metallic PCB (NMPCB) powders were measured, and the morphological, mechanical and thermal properties of the NMPCB/PVC composite material were investigated. The results show that recycled NMPCB powders, when added below a threshold, tended to increase the tensile strength and bending strength of PVC. When 20 wt% NMPCB powders (relative to the substrate PVC) of an average diameter of 0.08 mm were added, the composite tensile strength and bending strength reached 22.6 MPa and 39.83 MPa, respectively, representing 107.2% and 123.1% improvement over pure PVC. The elongation at break of the composite material reached 151.94% of that of pure PVC, while the Vicat softening temperature of the composite material did not increase significantly compared to the pure PVC. The above results suggest that paper-based NMPCB powders, when used at appropriate amounts, can be effective for toughening PVC. Thus, this study suggests a new route for reusing paper-based NMPCB, which may have a significant beneficial environmental impact.

  14. Designing a Battery-Less Piezoelectric based Energy Harvesting Interface Circuit with 300 mV Startup Voltage

    NASA Astrophysics Data System (ADS)

    Sarker, M. R.; Ali, Sawal H. Md; Othman, M.; Islam, Shabiul

    2013-04-01

    This paper presents a designing a battery-less piezoelectric based energy harvesting interface circuits with 300mV step-up voltage. A technique (i.e., DC-DC Step-Up converter) has chosen for designing the startup voltage with low voltage energy (i.e., 300mV). The proposed method consumes very little power, and is especially suitable for the ambient environmental source, where energy harvested power is very low. The energy harvesting interface circuit consists of MOSFET bridge ac-dc rectifier, voltage regulator, dc-dc step-up converter and an energy storage device with capacitor at the output terminal, replacing this by external battery. This paper will study results these important issues regarding the efficiencies of the energy harvesting power conversion interface circuits considering the storage device low voltage. The achievement of our development circuit is able to boost up minimum 1.67 V for input DC voltage of 300mV. The overall circuit efficiency is greater than 80% following the simulation results. This research has focused on the application of Wireless Sensor Network (WSN) and bio-medical device can be operated without battery.

  15. Wireless Charge Based Capacitance Measurement Circuits with On-Chip Spiral Inductor for Radio Frequency Identification Biosensor

    NASA Astrophysics Data System (ADS)

    Kim, Boram; Uno, Shigeyasu; Nakazato, Kazuo

    2012-04-01

    A wireless measuring system of charge based capacitance measurement (CBCM) circuit has been designed and demonstrated for biomedical applications. The radio frequency identification (RFID) chip that includes on-chip spiral inductor tag antenna, and RFID circuit, and CBCM sensor chip are fabricated within standard complementary metal oxide semiconductor (CMOS) process. The capacitance change caused by DNA detection can be converted into the voltage output using capacitance-to-voltage conversion circuit. To confirm the transmission of the capacitance, the poly-capacitor of fixed capacitance and on-chip spiral inductor tag antenna were fabricated using 1.2 µm, 2-metal, 2-poly CMOS technology. As a result of measurement, three different capacitances (34, 141, 564 fF) were detected wirelessly.

  16. A power management system for energy harvesting and wireless sensor networks application based on a novel charge pump circuit

    NASA Astrophysics Data System (ADS)

    Aloulou, R.; De Peslouan, P.-O. Lucas; Mnif, H.; Alicalapa, F.; Luk, J. D. Lan Sun; Loulou, M.

    2016-05-01

    Energy Harvesting circuits are developed as an alternative solution to supply energy to autonomous sensor nodes in Wireless Sensor Networks. In this context, this paper presents a micro-power management system for multi energy sources based on a novel design of charge pump circuit to allow the total autonomy of self-powered sensors. This work proposes a low-voltage and high performance charge pump (CP) suitable for implementation in standard complementary metal oxide semiconductor (CMOS) technologies. The CP design was implemented using Cadence Virtuoso with AMS 0.35μm CMOS technology parameters. Its active area is 0.112 mm2. Consistent results were obtained between the measured findings of the chip testing and the simulation results. The circuit can operate with an 800 mV supply and generate a boosted output voltage of 2.835 V with 1 MHz as frequency.

  17. AIB-OR: improving onion routing circuit construction using anonymous identity-based cryptosystems.

    PubMed

    Wang, Changji; Shi, Dongyuan; Xu, Xilei

    2015-01-01

    The rapid growth of Internet applications has made communication anonymity an increasingly important or even indispensable security requirement. Onion routing has been employed as an infrastructure for anonymous communication over a public network, which provides anonymous connections that are strongly resistant to both eavesdropping and traffic analysis. However, existing onion routing protocols usually exhibit poor performance due to repeated encryption operations. In this paper, we first present an improved anonymous multi-receiver identity-based encryption (AMRIBE) scheme, and an improved identity-based one-way anonymous key agreement (IBOWAKE) protocol. We then propose an efficient onion routing protocol named AIB-OR that provides provable security and strong anonymity. Our main approach is to use our improved AMRIBE scheme and improved IBOWAKE protocol in onion routing circuit construction. Compared with other onion routing protocols, AIB-OR provides high efficiency, scalability, strong anonymity and fault tolerance. Performance measurements from a prototype implementation show that our proposed AIB-OR can achieve high bandwidths and low latencies when deployed over the Internet. PMID:25815879

  18. Geometrical tuning art for entirely subwavelength grating waveguide based integrated photonics circuits.

    PubMed

    Wang, Zheng; Xu, Xiaochuan; Fan, Donglei; Wang, Yaguo; Subbaraman, Harish; Chen, Ray T

    2016-05-05

    Subwavelength grating (SWG) waveguide is an intriguing alternative to conventional optical waveguides due to the extra degree of freedom it offers in tuning a few important waveguide properties, such as dispersion and refractive index. Devices based on SWG waveguides have demonstrated impressive performances compared to conventional waveguides. However, the high loss of SWG waveguide bends jeopardizes their applications in integrated photonic circuits. In this work, we propose a geometrical tuning art, which realizes a pre-distorted refractive index profile in SWG waveguide bends. The pre-distorted refractive index profile can effectively reduce the mode mismatch and radiation loss simultaneously, thus significantly reduce the bend loss. This geometry tuning art has been numerically optimized and experimentally demonstrated in present study. Through such tuning, the average insertion loss of a 5 μm SWG waveguide bend is reduced drastically from 5.43 dB to 1.10 dB per 90° bend for quasi-TE polarization. In the future, the proposed scheme will be utilized to enhance performance of a wide range of SWG waveguide based photonics devices.

  19. Geometrical tuning art for entirely subwavelength grating waveguide based integrated photonics circuits

    DOE PAGES

    Wang, Zheng; Xu, Xiaochuan; Fan, Donglei; Wang, Yaguo; Subbaraman, Harish; Chen, Ray T.

    2016-05-05

    Here, subwavelength grating (SWG) waveguide is an intriguing alternative to conventional optical waveguides due to the extra degree of freedom it offers in tuning a few important waveguide properties, such as dispersion and refractive index. Devices based on SWG waveguides have demonstrated impressive performances compared to conventional waveguides. However, the high loss of SWG waveguide bends jeopardizes their applications in integrated photonic circuits. In this work, we propose a geometrical tuning art, which realizes a pre-distorted refractive index profile in SWG waveguide bends. The pre-distorted refractive index profile can effectively reduce the mode mismatch and radiation loss simultaneously, thus significantlymore » reduce the bend loss. This geometry tuning art has been numerically optimized and experimentally demonstrated in present study. Through such tuning, the average insertion loss of a 5 μm SWG waveguide bend is reduced drastically from 5.43 dB to 1.10 dB per 90° bend for quasi-TE polarization. In the future, the proposed scheme will be utilized to enhance performance of a wide range of SWG waveguide based photonics devices.« less

  20. AIB-OR: Improving Onion Routing Circuit Construction Using Anonymous Identity-Based Cryptosystems

    PubMed Central

    Wang, Changji; Shi, Dongyuan; Xu, Xilei

    2015-01-01

    The rapid growth of Internet applications has made communication anonymity an increasingly important or even indispensable security requirement. Onion routing has been employed as an infrastructure for anonymous communication over a public network, which provides anonymous connections that are strongly resistant to both eavesdropping and traffic analysis. However, existing onion routing protocols usually exhibit poor performance due to repeated encryption operations. In this paper, we first present an improved anonymous multi-receiver identity-based encryption (AMRIBE) scheme, and an improved identity-based one-way anonymous key agreement (IBOWAKE) protocol. We then propose an efficient onion routing protocol named AIB-OR that provides provable security and strong anonymity. Our main approach is to use our improved AMRIBE scheme and improved IBOWAKE protocol in onion routing circuit construction. Compared with other onion routing protocols, AIB-OR provides high efficiency, scalability, strong anonymity and fault tolerance. Performance measurements from a prototype implementation show that our proposed AIB-OR can achieve high bandwidths and low latencies when deployed over the Internet. PMID:25815879

  1. Geometrical tuning art for entirely subwavelength grating waveguide based integrated photonics circuits

    PubMed Central

    Wang, Zheng; Xu, Xiaochuan; Fan, Donglei; Wang, Yaguo; Subbaraman, Harish; Chen, Ray T.

    2016-01-01

    Subwavelength grating (SWG) waveguide is an intriguing alternative to conventional optical waveguides due to the extra degree of freedom it offers in tuning a few important waveguide properties, such as dispersion and refractive index. Devices based on SWG waveguides have demonstrated impressive performances compared to conventional waveguides. However, the high loss of SWG waveguide bends jeopardizes their applications in integrated photonic circuits. In this work, we propose a geometrical tuning art, which realizes a pre-distorted refractive index profile in SWG waveguide bends. The pre-distorted refractive index profile can effectively reduce the mode mismatch and radiation loss simultaneously, thus significantly reduce the bend loss. This geometry tuning art has been numerically optimized and experimentally demonstrated in present study. Through such tuning, the average insertion loss of a 5 μm SWG waveguide bend is reduced drastically from 5.43 dB to 1.10 dB per 90° bend for quasi-TE polarization. In the future, the proposed scheme will be utilized to enhance performance of a wide range of SWG waveguide based photonics devices. PMID:27145872

  2. Effects of circuit-based exercise programs on the body composition of elderly obese women

    PubMed Central

    Bocalini, Danilo Sales; Lima, Lucas S; de Andrade, Socrates; Madureira, Angelo; Rica, Roberta L; dos Santos, Rodrigo Nolasco; Serra, Andrey Jorge; Silva, Jose Antonio; Rodriguez, Daniel; Figueira, Aylton; Pontes, Francisco Luciano

    2012-01-01

    Aim The aim of this study was to investigate the impact of circuit-based exercise on the body composition in obese older women by focusing on physical exercise and body weight (BW) gain control in older people. Methods Seventy older women (>60 years old) voluntarily took part in the study. Participants were randomized into six different groups according to body mass index (BMI): appropriate weight (AW) control (AWC) and trained (AWT) groups, overweight (OW) control (OWC) and trained (OWT) groups, and obesity (O) control (OC) and trained (OT) groups. The exercise program consisted of 50 minutes of exercise three times per week for 12 weeks. The exercises were alternated between upper and lower body using rest between sets for 40 seconds with intensity controlled by heart rate (70% of work). The contraction time established was 5 seconds to eccentric and concentric muscular action phase. The following anthropometric parameters were evaluated: height (m), body weight (BW, kg), body fat (BF, %), fat mass (FM, kg), lean mass (LM, kg), and BMI (kg/m2). Results The values (mean ± standard deviation [SD]) of relative changes to BW (−8.0% ± 0.8%), BF (−21.4% ± 2.1%), LM (3.0% ± 0.3%), and FM (−31.2% ± 3.0%) to the OT group were higher (P < 0.05) than in the AWT (BW: −2.0% ± 1.1%; BF: −4.6% ± 1.8%; FM: −7.0% ± 2.8%; LM: 0.2% ± 1.1%) and OWT (BW: −4.5% ± 1.0%; BF: −11.0% ± 2.2%; FM: −16.1% ± 3.2%; LM: −0.2% ± 1.0%) groups; additionally, no differences were found for C groups. While reduction (P < 0.03) in BMI according to absolute values was observed for all trained groups (AWT: 22 ± 1 versus 21 ± 1; OWT: 27 ± 1 versus 25 ± 1, OT: 34 ± 1 versus 30 ± 1) after training, no differences were found for C groups. Conclusion In summary, circuit-based exercise is an effective method for promoting reduction in anthropometrics parameters in obese older women. PMID:23271901

  3. Recovery of copper and lead from waste printed circuit boards by supercritical water oxidation combined with electrokinetic process.

    PubMed

    Xiu, Fu-Rong; Zhang, Fu-Shen

    2009-06-15

    An effective and benign process for copper and lead recovery from waste printed circuit boards (PCBs) was developed. In the process, the PCBs was pre-treated in supercritical water, then subjected to electrokinetic (EK) process. Experimental results showed that supercritical water oxidation (SCWO) process was strong enough to decompose the organic compounds of PCBs, and XRD spectra indicated that copper and lead were oxidized into CuO, Cu(2)O and beta-PbO(2) in the process. The optimum SCWO treatment conditions were 60 min, 713 K, 30 MPa, and EK treatment time, constant current density were 11h, 20 mA cm(-2), respectively. The recovery percentages of copper and lead under optimum SCWO+EK treatment conditions were around 84.2% and 89.4%, respectively. In the optimized EK treatment, 74% of Cu was recovered as a deposit on the cathode with a purity of 97.6%, while Pb was recovered as concentrated solutions in either anode (23.1%) or cathode (66.3%) compartments but little was deposited on the electrodes. It is believed that the process is effective and practical for Cu and Pb recovery from waste electric and electronic equipments.

  4. Plasmonic and electronic device-based integrated circuits and their characteristics

    NASA Astrophysics Data System (ADS)

    Sakai, H.; Okahisa, S.; Nakayama, Y.; Nakayama, K.; Fukuhara, M.; Kimura, Y.; Ishii, Y.; Fukuda, M.

    2016-11-01

    This paper presents a plasmonic circuit that has been monolithically integrated with electronic devices on a silicon substrate and then discusses the concept behind this circuit. To form the proposed circuit, two plasmonic waveguides and a detector are integrated with metal-oxide-semiconductor field-effect transistors (MOSFETs) on the substrate. In the circuit, intensity signals or coherent plasmonic signals are generated by coherent light at an operating wavelength at which silicon is transparent, and these signals propagate along the waveguides before they are converted into electrical signals by the detector. These electrical intensity and coherent signals then drive the MOSFETs during both DC and AC operation. The measured performances of the devices indicate that surface plasmon polaritons propagate on the metal surface at the speed of light and drive the electronic devices without any absorption in the silicon.

  5. Remote reset circuit

    DOEpatents

    Gritzo, Russell E.

    1987-01-01

    A remote reset circuit acts as a stand-alone monitor and controller by clocking in each character sent by a terminal to a computer and comparing it to a given reference character. When a match occurs, the remote reset circuit activates the system's hardware reset line. The remote reset circuit is hardware based centered around monostable multivibrators and is unaffected by system crashes, partial serial transmissions, or power supply transients.

  6. Remote reset circuit

    DOEpatents

    Gritzo, R.E.

    1985-09-12

    A remote reset circuit acts as a stand-along monitor and controller by clocking in each character sent by a terminal to a computer and comparing it to a given reference character. When a match occurs, the remote reset circuit activates the system's hardware reset line. The remote reset circuit is hardware based centered around monostable multivibrators and is unaffected by system crashes, partial serial transmissions, or power supply transients. 4 figs.

  7. Understanding virulence mechanisms in M. tuberculosis infection via a circuit-based simulation framework.

    SciTech Connect

    May, Elebeoba Eni; Oprea, Tudor I.; Joo, Jaewook; Misra, Milind; Leitao, Andrei; Faulon, Jean-Loup Michel

    2008-08-01

    Tuberculosis (TB), caused by the bacterium Mycobacterium tuberculosis (Mtb), is a growing international health crisis. Mtb is able to persist in host tissues in a non-replicating persistent (NRP) or latent state. This presents a challenge in the treatment of TB. Latent TB can re-activate in 10% of individuals with normal immune systems, higher for those with compromised immune systems. A quantitative understanding of latency-associated virulence mechanisms may help researchers develop more effective methods to battle the spread and reduce TB associated fatalities. Leveraging BioXyce's ability to simulate whole-cell and multi-cellular systems we are developing a circuit-based framework to investigate the impact of pathogenicity-associated pathways on the latency/reactivation phase of tuberculosis infection. We discuss efforts to simulate metabolic pathways that potentially impact the ability of Mtb to persist within host immune cells. We demonstrate how simulation studies can provide insight regarding the efficacy of potential anti-TB agents on biological networks critical to Mtb pathogenicity using a systems chemical biology approach

  8. Portable optical epidural needle-a CMOS-based system solution and its circuit design.

    PubMed

    Gong, Cihun-Siyong Alex; Lin, Shih-Pin; Mandell, M Susan; Tsou, Mei-Yung; Chang, Yin; Ting, Chien-Kun

    2014-01-01

    Epidural anesthesia is a common anesthesia method yet up to 10% of procedures fail to provide adequate analgesia. This is usually due to misinterpreting the tactile information derived from the advancing needle through the complex tissue planes. Incorrect placement also can cause dural puncture and neural injury. We developed an optic system capable of reliably identifying tissue planes surrounding the epidural space. However the new technology was too large and cumbersome for practical clinical use. We present a miniaturized version of our optic system using chip technology (first generation CMOS-based system) for logic functions. The new system was connected to an alarm that was triggered once the optic properties of the epidural were identified. The aims of this study were to test our miniaturized system in a porcine model and describe the technology to build this new clinical tool. Our system was tested in a porcine model and identified the epidural space in the lumbar, low and high thoracic regions of the spine. The new technology identified the epidural space in all but 1 of 46 attempts. Experimental results from our fabricated integrated circuit and animal study show the new tool has future clinical potential.

  9. Contact-induced crystallinity for high-performance soluble acene-based transistors and circuits

    NASA Astrophysics Data System (ADS)

    Gundlach, D. J.; Royer, J. E.; Park, S. K.; Subramanian, S.; Jurchescu, O. D.; Hamadani, B. H.; Moad, A. J.; Kline, R. J.; Teague, L. C.; Kirillov, O.; Richter, C. A.; Kushmerick, J. G.; Richter, L. J.; Parkin, S. R.; Jackson, T. N.; Anthony, J. E.

    2008-03-01

    The use of organic materials presents a tremendous opportunity to significantly impact the functionality and pervasiveness of large-area electronics. Commercialization of this technology requires reduction in manufacturing costs by exploiting inexpensive low-temperature deposition and patterning techniques, which typically lead to lower device performance. We report a low-cost approach to control the microstructure of solution-cast acene-based organic thin films through modification of interfacial chemistry. Chemically and selectively tailoring the source/drain contact interface is a novel route to initiating the crystallization of soluble organic semiconductors, leading to the growth on opposing contacts of crystalline films that extend into the transistor channel. This selective crystallization enables us to fabricate high-performance organic thin-film transistors and circuits, and to deterministically study the influence of the microstructure on the device characteristics. By connecting device fabrication to molecular design, we demonstrate that rapid film processing under ambient room conditions and high performance are not mutually exclusive.

  10. Portable Optical Epidural Needle-A CMOS-Based System Solution and Its Circuit Design

    PubMed Central

    Gong, Cihun-Siyong Alex; Lin, Shih-Pin; Mandell, M. Susan; Tsou, Mei-Yung; Chang, Yin; Ting, Chien-Kun

    2014-01-01

    Epidural anesthesia is a common anesthesia method yet up to 10% of procedures fail to provide adequate analgesia. This is usually due to misinterpreting the tactile information derived from the advancing needle through the complex tissue planes. Incorrect placement also can cause dural puncture and neural injury. We developed an optic system capable of reliably identifying tissue planes surrounding the epidural space. However the new technology was too large and cumbersome for practical clinical use. We present a miniaturized version of our optic system using chip technology (first generation CMOS-based system) for logic functions. The new system was connected to an alarm that was triggered once the optic properties of the epidural were identified. The aims of this study were to test our miniaturized system in a porcine model and describe the technology to build this new clinical tool. Our system was tested in a porcine model and identified the epidural space in the lumbar, low and high thoracic regions of the spine. The new technology identified the epidural space in all but 1 of 46 attempts. Experimental results from our fabricated integrated circuit and animal study show the new tool has future clinical potential. PMID:25162150

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

    PubMed

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

    2015-02-01

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

  12. Device variability and circuit redundancy in signal processing based on nanoswitches

    NASA Astrophysics Data System (ADS)

    Cervera, Javier; Manzanares, José A.; Mafé, Salvador

    2009-11-01

    Signal processing based on molecular switches whose conductance can be tuned by an external stimulus between two (on and off) states has been proposed recently (Cervera et al 2008 J. Appl. Phys. 104 084317). The basic building block is a metal nanoparticle linked to two electrodes by an organic ligand and a nanoswitch. The net charge delivered by this nanostructure exhibits a sharp resonance when the alternating potential applied between the electrodes has the same frequency as the periodic variation between the on and off conductance states induced on the nanoswitch. This resonance can be used to process an external signal by selectively extracting the weight of the different harmonics. However, because of the fabrication process at the nanoscale, the nanostructures will show a significant variability in the physical characteristics. By using a phenomenological model that includes this variability, the stochastic nature of electron transference, and the thermal noise, we demonstrate that reliable signal processing can still be achieved by adapting the number of nanoswitches per bit of information (circuit redundancy) to the nanostructure tolerance (device variability). Extensive kinetic Monte Carlo simulations show that a moderate level of redundancy can compensate for significant nanostructure variability. This result gives support to the concept of ensembles of redundant switches as reliable components for signal processing at the nanoscale.

  13. Fully Programmable Ring-Resonator-Based Integrated Photonic Circuit for Phase Coherent Applications

    NASA Astrophysics Data System (ADS)

    Agarwal, Anjali; Toliver, Paul; Menendez, Ronald; Etemad, Shahab; Jackel, Janet; Young, Jeffrey; Banwell, Thomas; Little, B. E.; Chu, S. T.; Chen, Wei; Chen, Wenlu; Hryniewicz, J.; Johnson, F.; Gill, D.; King, O.; Davidson, R.; Donovan, K.; Delfyett, Peter J.

    2006-01-01

    A novel ring-resonator-based integrated photonic chip with ultrafine frequency resolution, providing programmable, stable, and accurate optical-phase control is demonstrated. The ability to manipulate the optical phase of the individual frequency components of a signal is a powerful tool for optical communications, signal processing, and RF photonics applications. As a demonstration of the power of these components, we report their use as programmable spectral-phase encoders (SPEs) and decoders for wavelength-division-multiplexing (WDM)-compatible optical code-division multiple access (OCDMA). Most important for the application here, the high resolution of these ring-resonator circuits makes possible the independent control of the optical phase of the individual tightly spaced frequency lines of a mode-locked laser (MLL). This unique approach allows us to limit the coded signal's spectral bandwidth, thereby allowing for high spectral efficiency (compared to other OCDMA systems) and compatibility with existing WDM systems with a rapidly reconfigurable set of codes. A four-user OCDMA system using polarization multiplexing is shown to operate at data rates of 2.5 Gb/s within a 40-GHz transparent optical window with a bit error rate (BER) better than 10-9 and a spectral efficiency of 25%.

  14. Simultaneous detection of lactate and glucose by integrated printed circuit board based array sensing chip.

    PubMed

    Li, Xuelian; Zang, Jianfeng; Liu, Yingshuai; Lu, Zhisong; Li, Qing; Li, Chang Ming

    2013-04-10

    An integrated printed circuit board (PCB) based array sensing chip was developed to simultaneously detect lactate and glucose in mouse serum. The novelty of the chip relies on a concept demonstration of inexpensive high-throughput electronic biochip, a chip design for high signal to noise ratio and high sensitivity by construction of positively charged chitosan/redox polymer Polyvinylimidazole-Os (PVI-Os)/carbon nanotube (CNT) composite sensing platform, in which the positively charged chitosan/PVI-Os is mediator and electrostatically immobilizes the negatively charged enzyme, while CNTs function as an essential cross-linker to network PVI-Os and chitosan due to its negative charged nature. Additional electrodes on the chip with the same sensing layer but without enzymes were prepared to correct the interferences for high specificity. Low detection limits of 0.6 μM and 5 μM were achieved for lactate and glucose, respectively. This work could be extended to inexpensive array sensing chips with high sensitivity, good specificity and high reproducibility for various sensor applications.

  15. Silicon-based optoelectronic integrated circuit for label-free bio/chemical sensor.

    PubMed

    Song, Junfeng; Luo, Xianshu; Kee, Jack Sheng; Han, Kyungsup; Li, Chao; Park, Mi Kyoung; Tu, Xiaoguang; Zhang, Huijuan; Fang, Qing; Jia, Lianxi; Yoon, Yong-Jin; Liow, Tsung-Yang; Yu, Mingbin; Lo, Guo-Qiang

    2013-07-29

    We demonstrate a silicon-based optoelectronic integrated circuit (OEIC) for label-free bio/chemical sensing application. Such on-chip OEIC sensor system consists of optical grating couplers for vertical light coupling into silicon waveguides, a thermal-tunable microring as a tunable filter, an exposed microring as an optical label-free sensor, and a Ge photodetector for a direct electrical readout. Different from the conventional wavelength-scanning method, we adopt low-cost broadband ASE light source, together with the on-chip tunable filter to generate sliced light source. The effective refractive index change of the sensing microring induced by the sensing target is traced by scanning the supplied electrical power applied onto the tracing microring, and the detected electrical signal is read out by the Ge photodetector. For bulk refractive index sensing, we demonstrate using such OEIC sensing system with a sensitivity of ~15 mW/RIU and a detection limit of 3.9 μ-RIU, while for surface sensing of biotin-streptavidin, we obtain a surface mass sensitivity of S(m) = ~192 µW/ng·mm(-2) and a surface detection limit of 0.3 pg/mm(2). The presented OEIC sensing system is suitable for point-of-care applications.

  16. Silicon-based optoelectronic integrated circuit for label-free bio/chemical sensor.

    PubMed

    Song, Junfeng; Luo, Xianshu; Kee, Jack Sheng; Han, Kyungsup; Li, Chao; Park, Mi Kyoung; Tu, Xiaoguang; Zhang, Huijuan; Fang, Qing; Jia, Lianxi; Yoon, Yong-Jin; Liow, Tsung-Yang; Yu, Mingbin; Lo, Guo-Qiang

    2013-07-29

    We demonstrate a silicon-based optoelectronic integrated circuit (OEIC) for label-free bio/chemical sensing application. Such on-chip OEIC sensor system consists of optical grating couplers for vertical light coupling into silicon waveguides, a thermal-tunable microring as a tunable filter, an exposed microring as an optical label-free sensor, and a Ge photodetector for a direct electrical readout. Different from the conventional wavelength-scanning method, we adopt low-cost broadband ASE light source, together with the on-chip tunable filter to generate sliced light source. The effective refractive index change of the sensing microring induced by the sensing target is traced by scanning the supplied electrical power applied onto the tracing microring, and the detected electrical signal is read out by the Ge photodetector. For bulk refractive index sensing, we demonstrate using such OEIC sensing system with a sensitivity of ~15 mW/RIU and a detection limit of 3.9 μ-RIU, while for surface sensing of biotin-streptavidin, we obtain a surface mass sensitivity of S(m) = ~192 µW/ng·mm(-2) and a surface detection limit of 0.3 pg/mm(2). The presented OEIC sensing system is suitable for point-of-care applications. PMID:23938665

  17. Pulse-driven LED circuit with transformer-based current balance technique

    NASA Astrophysics Data System (ADS)

    Kwak, S.-S.

    2014-12-01

    Light emitting diodes (LEDs) have been gradually used for backlight modules for liquid crystal display as a substitute for cold cathode fluorescent lamps. In most of LED applications, it is required to connect several LED strings in parallel to limit the dc voltage level to be applied to the single LED string. Due to considerable current variations through each LED string with inevitable parameter deviations as well as temperature and ageing effects, techniques to balance currents flowing through LED strings are required for LED drivers. This article proposes a pulse-driven LED circuit with transformer-based current balancing scheme, which can simply regulate currents through the LED strings. The transformers are placed in series with the LED strings in such a way that the LED currents are automatically balanced. Since the developed current sharing technique employs no dissipative resistors and no linear-mode transistors, the proposed driver has high efficiency, low power dissipation and reduced thermal problems. In addition, the presented driver with no additional semiconductor devices and no additional controllers can provide a simple and a cost-effective current balancing solution, compared to conventional approaches. Thus, the proposed LED driver can feature a simple, highly efficient, reliable and cost-effective method. The presented LED driver is verified with experimental results.

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

    PubMed

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

    2015-02-01

    A new design of DC hybrid circuit breaker based on high-speed switch (HSS) and arc generator (AG), which can drastically profit from low heat loss in normal state and fast current breaking under fault state, is presented and analyzed in this paper. AG is designed according to the magnetic pinch effect of liquid metal. By utilizing the arc voltage generated across AG, the fault current is rapidly commutated from HSS into parallel connected branch. As a consequence, the arcless open of HSS is achieved. The post-arc conducting resume time (Δ tc) of AG and the commutation original voltage (Uc), two key factors in the commutation process, are investigated experimentally. Particularly, influences of the liquid metal channel diameter (Φ) of AG, fault current rate of rise (di/dt) and Uc on Δ tc are focused on. Furthermore, a suitable Uc is determined during the current commutation process, aiming at the reliable arcless open of HSS and short breaking time. Finally, the fault current breaking test is carried out for the current peak value of 11.8 kA, and the validity of the design is confirmed by the experimental results. PMID:25725867

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

  20. Combining Flux Balance and Energy Balance Analysis for Large-Scale Metabolic Network: Biochemical Circuit Theory for Analysis of Large-Scale Metabolic Networks

    NASA Technical Reports Server (NTRS)

    Beard, Daniel A.; Liang, Shou-Dan; Qian, Hong; Biegel, Bryan (Technical Monitor)

    2001-01-01

    Predicting behavior of large-scale biochemical metabolic networks represents one of the greatest challenges of bioinformatics and computational biology. Approaches, such as flux balance analysis (FBA), that account for the known stoichiometry of the reaction network while avoiding implementation of detailed reaction kinetics are perhaps the most promising tools for the analysis of large complex networks. As a step towards building a complete theory of biochemical circuit analysis, we introduce energy balance analysis (EBA), which compliments the FBA approach by introducing fundamental constraints based on the first and second laws of thermodynamics. Fluxes obtained with EBA are thermodynamically feasible and provide valuable insight into the activation and suppression of biochemical pathways.

  1. Stability study of a gyrotron-traveling-wave amplifier based on a lossy dielectric-loaded mode-selective circuit

    SciTech Connect

    Du Chaohai; Liu Pukun

    2009-07-15

    The millimeter microwave source of gyrotron-traveling-wave amplifier (gyro-TWT) is capable of generating high power coherent radiation in a broad bandwidth, while its performance is severely deteriorated by the stability problems. This paper focuses on modeling and the stability analysis of the Naval Research Laboratory (NRL) Ka-band TE{sub 01} mode gyro-TWT based on an interaction circuit alternately loaded with lossy ceramic shells and metal rings. The propagation characteristics of the interaction circuit is analyzed first, based on which the boundary impedance method is employed to build an equivalent uniform lossy circuit. Then the stability of the interaction system is studied using linear and nonlinear theories. The analysis reveals that, due to the special waveguide structure and the dielectric loss, the propagation characteristics of the complex waveguide are similar to that of a uniform lossy circuit. The analysis of the absolute instabilities characterizes the roles the forward-backward-wave components played. The study indicates that the lowest threshold current of the absolute instabilities is higher than the operating current, which brings the system high stability. The reliability of the analysis is proved by the consistency between the analysis and the NRL experimental results.

  2. Combining ChIP-chip and Expression Profiling to Model the MoCRZ1 Mediated Circuit for Ca2+/Calcineurin Signaling in the Rice Blast Fungus

    PubMed Central

    Kim, Soonok; Hu, Jinnan; Oh, Yeonyee; Park, Jongsun; Choi, Jinhee; Lee, Yong-Hwan; Dean, Ralph A.; Mitchell, Thomas K.

    2010-01-01

    Significant progress has been made in defining the central signaling networks in many organisms, but collectively we know little about the downstream targets of these networks and the genes they regulate. To reconstruct the regulatory circuit of calcineurin signal transduction via MoCRZ1, a Magnaporthe oryzae C2H2 transcription factor activated by calcineurin dephosphorylation, we used a combined approach of chromatin immunoprecipitation - chip (ChIP-chip), coupled with microarray expression studies. One hundred forty genes were identified as being both a direct target of MoCRZ1 and having expression concurrently differentially regulated in a calcium/calcineurin/MoCRZ1 dependent manner. Highly represented were genes involved in calcium signaling, small molecule transport, ion homeostasis, cell wall synthesis/maintenance, and fungal virulence. Of particular note, genes involved in vesicle mediated secretion necessary for establishing host associations, were also found. MoCRZ1 itself was a target, suggesting a previously unreported autoregulation control point. The data also implicated a previously unreported feedback regulation mechanism of calcineurin activity. We propose that calcium/calcineurin regulated signal transduction circuits controlling development and pathogenicity manifest through multiple layers of regulation. We present results from the ChIP-chip and expression analysis along with a refined model of calcium/calcineurin signaling in this important plant pathogen. PMID:20502632

  3. ADDER CIRCUIT

    DOEpatents

    Jacobsohn, D.H.; Merrill, L.C.

    1959-01-20

    An improved parallel addition unit is described which is especially adapted for use in electronic digital computers and characterized by propagation of the carry signal through each of a plurality of denominationally ordered stages within a minimum time interval. In its broadest aspects, the invention incorporates a fast multistage parallel digital adder including a plurality of adder circuits, carry-propagation circuit means in all but the most significant digit stage, means for conditioning each carry-propagation circuit during the time period in which information is placed into the adder circuits, and means coupling carry-generation portions of thc adder circuit to the carry propagating means.

  4. An Integrated Circuit for Chip-Based Analysis of Enzyme Kinetics and Metabolite Quantification.

    PubMed

    Cheah, Boon Chong; Macdonald, Alasdair Iain; Martin, Christopher; Streklas, Angelos J; Campbell, Gordon; Al-Rawhani, Mohammed A; Nemeth, Balazs; Grant, James P; Barrett, Michael P; Cumming, David R S

    2016-06-01

    We have created a novel chip-based diagnostic tools based upon quantification of metabolites using enzymes specific for their chemical conversion. Using this device we show for the first time that a solid-state circuit can be used to measure enzyme kinetics and calculate the Michaelis-Menten constant. Substrate concentration dependency of enzyme reaction rates is central to this aim. Ion-sensitive field effect transistors (ISFET) are excellent transducers for biosensing applications that are reliant upon enzyme assays, especially since they can be fabricated using mainstream microelectronics technology to ensure low unit cost, mass-manufacture, scaling to make many sensors and straightforward miniaturisation for use in point-of-care devices. Here, we describe an integrated ISFET array comprising 2(16) sensors. The device was fabricated with a complementary metal oxide semiconductor (CMOS) process. Unlike traditional CMOS ISFET sensors that use the Si3N4 passivation of the foundry for ion detection, the device reported here was processed with a layer of Ta2O5 that increased the detection sensitivity to 45 mV/pH unit at the sensor readout. The drift was reduced to 0.8 mV/hour with a linear pH response between pH 2-12. A high-speed instrumentation system capable of acquiring nearly 500 fps was developed to stream out the data. The device was then used to measure glucose concentration through the activity of hexokinase in the range of 0.05 mM-231 mM, encompassing glucose's physiological range in blood. Localised and temporal enzyme kinetics of hexokinase was studied in detail. These results present a roadmap towards a viable personal metabolome machine.

  5. Analysis of WC/Ni-Based Coatings Deposited by Controlled Short-Circuit MIG Welding

    NASA Astrophysics Data System (ADS)

    Vespa, P.; Pinard, P. T.; Gauvin, R.; Brochu, M.

    2012-06-01

    This study investigates the recently developed controlled short-circuit metal inert gas (CSC-MIG) welding system for depositing WC/Ni-based claddings on carbon steel substrates. WC/Ni-based coatings deposited by CSC-MIG were analyzed by optical light microscopy and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and electron backscatter diffraction (EBSD) capabilities. X-ray diffraction (XRD) and hardness measurements of depositions are also reported. The CSC-MIG welding system provides a significant amount of user control over the current waveform during welding and has lower heat input when compared with traditional MIG welding. Heat input for the analyzed coatings ranged from 10.1 to 108.7 J/mm. Metallurgically bonded coatings free from spatter and with 0.75% average porosity were produced. It was found that the detrimental decarburization of the WC particles seen in thermal spray systems does not occur when welding with the CSC-MIG. Precipitation of a reaction layer around the reinforcing phase was identified as WC; the average thickness of which increases from 3.8 to 7.2 μm for the low and high heat input condition, respectively. Precipitation of newly formed WC particles was observed; their size distribution increased from D 50 of 2.4 μm in the low heat input weldment to 6.75 μm in the high heat input weldment. The level of dilution of the reinforcing phase increases significantly with heat input. The hardness of the deposited coatings decreases from 587 HV10 to 410 HV10 when the energy input was increased from 10.1 to 108.7 J/mm.

  6. The correlation of open-circuit voltage with bandgap in amorphous silicon-based pin solar cells

    NASA Astrophysics Data System (ADS)

    Crandall, R. S.; Schiff, E. A.

    1996-01-01

    We briefly review the correlation of open-circuit voltages VOC with the bandgap of the intrinsic layer in amorphous silicon based pin solar cells. We discuss two mechanisms which limit VOC: intrinsic layer recombination, and the built-in potential VBI. In particular we discuss Li's proposal that the open-circuit voltages in higher bandgap cells (EG>1.9 eV) are VBI-limited. Based on computer simulations of pin solar cells we propose that VBI limitation occurs when the recombination limit to VOC exceeds the cell's field-reversal voltage VR. For a-Si:H based cells this field-reversal voltage occurs at about VBI-0.3 V. This proposal would account for the observation that VBI limitation occurs for VOC significantly smaller than VBI.

  7. SPOCK: A SPICE based circuit code for modeling pulsed power machines

    SciTech Connect

    Ingermanson, R.; Parks, D.

    1996-12-31

    SPICE is an industry standard electrical circuit simulation code developed by the University of California at Berkeley over the last twenty years. The authors have developed a number of new SPICE devices of interest to the pulsed power community: plasma opening switches, plasma radiation sources, bremsstrahlung diodes, magnetically insulated transmission lines, explosively driven flux compressors. These new devices are integrated into SPICE using S-Cubed`s MIRIAD technology to create a user-friendly circuit code that runs on Unix workstations or under Windows NT or Windows 95. The new circuit code is called SPOCK--``S-Cubed Power Optimizing Circuit Kit.`` SPOCK allows the user to easily run optimization studies by setting up runs in which any circuit parameters can be systematically varied. Results can be plotted as 1-D line plots, 2-D contour plots, or 3-D ``bedsheet`` plots. The authors demonstrate SPOCK`s capabilities on a color laptop computer, performing realtime analysis of typical configurations of such machines as HAWK and ACE4.

  8. Combining Multiple Pairwise Structure-based Alignments

    SciTech Connect

    2014-11-12

    CombAlign is a new Python code that generates a gapped, one-to-many, multiple structure-based sequence alignment(MSSA) given a set of pairwise structure-based alignments. In order to better define regions of similarity among related protein structures, it is useful to detect the residue-residue correspondences among a set of pairwise structure alignments. Few codes exist for constructing a one-to-many, multiple sequence alignment derived from a set of structure alignments, and we perceived a need for creating a new tool for combing pairwise structure alignments that would allow for insertion of gaps in the reference structure.

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

    PubMed Central

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

    2015-01-01

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

  10. Power-efficient oscillator-based readout circuit for multichannel resonant volatile sensors.

    PubMed

    Pettine, Julia; Petrescu, Violeta; Karabacak, Devrez Mehmet; Vandecasteele, Marianne; Crego-Calama, Mercedes; Van Hoof, Chris

    2012-12-01

    This work presents a multichannel electronic nose system that enables a range of novel applications owing to high sensitivity, low form factor and low power consumption. Each channel is based on a combination of doubly-clamped piezoelectric MEMS resonators and CMOS oscillator-based readout designed in TSMC 0.25 μm technology. Using "application specific" polymer coatings, the individual resonators can be tuned to detect mixtures of volatile organic compounds (VOCs). This system achieves ppm-level theoretical limit of detection for ethanol which paves the way towards a broad range of applications such as personalized health and environment air quality.

  11. Relay Protection and Automation Systems Based on Programmable Logic Integrated Circuits

    SciTech Connect

    Lashin, A. V. Kozyrev, A. V.

    2015-09-15

    One of the most promising forms of developing the apparatus part of relay protection and automation devices is considered. The advantages of choosing programmable logic integrated circuits to obtain adaptive technological algorithms in power system protection and control systems are pointed out. The technical difficulties in the problems which today stand in the way of using relay protection and automation systems are indicated and a new technology for solving these problems is presented. Particular attention is devoted to the possibility of reconfiguring the logic of these devices, using programmable logic integrated circuits.

  12. Combining Multiple Pairwise Structure-based Alignments

    2014-11-12

    CombAlign is a new Python code that generates a gapped, one-to-many, multiple structure-based sequence alignment(MSSA) given a set of pairwise structure-based alignments. In order to better define regions of similarity among related protein structures, it is useful to detect the residue-residue correspondences among a set of pairwise structure alignments. Few codes exist for constructing a one-to-many, multiple sequence alignment derived from a set of structure alignments, and we perceived a need for creating a newmore » tool for combing pairwise structure alignments that would allow for insertion of gaps in the reference structure.« less

  13. Experimental determination of circuit equations

    NASA Astrophysics Data System (ADS)

    Shulman, Jason; Malatino, Frank; Widjaja, Matthew; Gunaratne, Gemunu H.

    2015-01-01

    Kirchhoff's laws offer a general, straightforward approach to circuit analysis. Unfortunately, their application becomes impractical for all but the simplest of circuits. This work presents an alternative procedure, based on an approach developed to analyze complex networks, thus making it appropriate for use on large, complicated circuits. The procedure is unusual in that it is not an analytic method but is based on experiment. Yet, this approach produces the same circuit equations obtained by more traditional means.

  14. Gallium Arsenide Domino Circuit

    NASA Technical Reports Server (NTRS)

    Yang, Long; Long, Stephen I.

    1990-01-01

    Advantages include reduced power and high speed. Experimental gallium arsenide field-effect-transistor (FET) domino circuit replicated in large numbers for use in dynamic-logic systems. Name of circuit denotes mode of operation, which logic signals propagate from each stage to next when successive stages operated at slightly staggered clock cycles, in manner reminiscent of dominoes falling in a row. Building block of domino circuit includes input, inverter, and level-shifting substages. Combinational logic executed in input substage. During low half of clock cycle, result of logic operation transmitted to following stage.

  15. An Internal ALD-Based High Voltage Divider and Signal Circuit for MCP-based Photodetectors

    SciTech Connect

    Adams, Bernhard W.; Elagin, Andrey; Elam, Jeffrey W.; Frisch, Henry J.; Genat, Jean-Francois; Gregar, Joseph S.; Mane, Anil U.; Minot, Michael J.; Northrup, Richard; Obaid, Razib; Oberla, Eric; Alexander, Vostrikov; Wetstein, Matthew

    2015-04-21

    We describe a pin-less design for the high voltage (HV) resistive divider of the all-glass LAPPD (TM) 8 in,square thin photodetector module. The divider, which distributes high voltage applied to the photocathode to the two micro-channel plates (MCPs) that constitute the amplification stage, is comprised of the two MCPs and three glass mechanical spacers, each of which is coated with a resistive layer using atomic layer deposition (ALD). The three glass grid spacers and the two MCPs form a continuous resistive path between cathode and anode, with the voltages across the MCPs and the spacers determined by the resistance of each. High voltage is applied on an external tab on the top glass window that connects to the photocathode through the metal seal. The DC ground is supplied by microstrips on the bottom glass plate that form the high-bandwidth anode. The microstrips exit the package through the glass-frit seal of the anode base-plate and the package sidewall. The divider is thus completely internal, with no HV pins penetrating the low-profile flat glass package. Measurements of the performance of the divider are presented for the 8 in.-square MCP and spacer package in a custom test fixture and for an assembled externally pumped LAPPD (TM) prototype with an aluminum photocathode. (C) 2015 Elsevier B.V. All rights reserved.

  16. An internal ALD-based high voltage divider and signal circuit for MCP-based photodetectors

    NASA Astrophysics Data System (ADS)

    Adams, Bernhard W.; Elagin, Andrey; Elam, Jeffrey W.; Frisch, Henry J.; Genat, Jean-Francois; Gregar, Joseph S.; Mane, Anil U.; Minot, Michael J.; Northrop, Richard; Obaid, Razib; Oberla, Eric; Vostrikov, Alexander; Wetstein, Matthew

    2015-04-01

    We describe a pin-less design for the high voltage (HV) resistive divider of the all-glass LAPPDTM 8 in.-square thin photodetector module. The divider, which distributes high voltage applied to the photocathode to the two micro-channel plates (MCPs) that constitute the amplification stage, is comprised of the two MCPs and three glass mechanical spacers, each of which is coated with a resistive layer using atomic layer deposition (ALD). The three glass grid spacers and the two MCPs form a continuous resistive path between cathode and anode, with the voltages across the MCPs and the spacers determined by the resistance of each. High voltage is applied on an external tab on the top glass window that connects to the photocathode through the metal seal. The DC ground is supplied by microstrips on the bottom glass plate that form the high-bandwidth anode. The microstrips exit the package through the glass-frit seal of the anode base-plate and the package sidewall. The divider is thus completely internal, with no HV pins penetrating the low-profile flat glass package. Measurements of the performance of the divider are presented for the 8 in.-square MCP and spacer package in a custom test fixture and for an assembled externally pumped LAPPDTM prototype with an aluminum photocathode.

  17. A modified circuit topology for inductive pulsed power supply based on HTSPPTs

    NASA Astrophysics Data System (ADS)

    Li, Haitao; Zhang, Cunshan; Wang, Teng; Gao, Mingliang; Li, Zhenmei; Zou, Guofeng

    2016-10-01

    High temperature superconducting pulsed power transformer (HTSPPT) provides an efficient method for inductive energy storage and current multiplication. The primary inductor of HTSPPT used for energy storage is made of high temperature superconducting coils, and the secondary inductor used for current pulse generation is made of normal conductor coils. In the initial circuit, the secondary inductor generates current pulse by switching out the coupled primary superconducting inductor. However, during the switching period, the leakage flux caused by imperfect coupling and the sudden change in primary current induce a voltage across the opening switch which exceeds the affordability of modern solid-state switches. In previous studies, a half-cycle oscillatory discharge circuit is proposed to mitigate these problems by using a capacitor to recapture the energy in the leakage flux and to slow down the turnoff of current in the primary. However, there are still some problems should be settled. For example, the output pulse cannot be adjusted, the residual energy cannot be recovered and the capacitor branch circuit may have an impact on the charging process. In the paper, a modified discharge circuit topology is introduced to solve these problems. A multi-module system comprising of several HTSPPTs charging in series connection and discharging in parallel is also designed and simulated. This system can be used to power an electromagnetic emission device.

  18. A new synchronization control circuit based on FPGA for the laser range-gated imaging system

    NASA Astrophysics Data System (ADS)

    He, Shan; Li, Li; Zhou, Yan

    2009-07-01

    Synchronization control is a kernel technique of the laser range-gated (LRG) imaging system which controls the synchronization of the pulsed laser and the ICCD camera directly. It can achieve range gating effectively and improve the resolution of image precisely. Conventional control circuits which are composed of discrete components have a poor performance of anti-interference, and the transmitting signal has a bad delay which affects the conventional circuit’s precision and stabilization seriously. To solve these problems, a range-gated synchronization control circuit is designed. This circuit, which takes the advantages of FPGA’s high compact and flexibility, uses the phase-locking-loop (PLL) to multiply the global clock frequency. This design improves the precision and stabilization greatly, makes the precision up to a nanosecond level and provides a real-time selection of the values of pulse width and delays. Experiments results indicate that this circuit has a high precise and stable range-gated pulse.

  19. A Charge-Based Low-Power High-SNR Capacitive Sensing Interface Circuit

    PubMed Central

    Peng, Sheng-Yu; Qureshi, Muhammad S.; Hasler, Paul E.; Basu, Arindam; Degertekin, F. L.

    2008-01-01

    This paper describes a low-power approach to capacitive sensing that achieves a high signal-to-noise ratio. The circuit is composed of a capacitive feedback charge amplifier and a charge adaptation circuit. Without the adaptation circuit, the charge amplifier only consumes 1 μW to achieve the audio band SNR of 69.34dB. An adaptation scheme using Fowler-Nordheim tunneling and channel hot electron injection mechanisms to stabilize the DC output voltage is demonstrated. This scheme provides a very low frequency pole at 0.2Hz. The measured noise spectrums show that this slow-time scale adaptation does not degrade the circuit performance. The DC path can also be provided by a large feedback resistance without causing extra power consumption. A charge amplifier with a MOS-bipolar pseudo-resistor feedback scheme is interfaced with a capacitive micromachined ultrasonic transducer to demonstrate the feasibility of this approach for ultrasound applications. PMID:18787650

  20. An Integer Programming-Based Generalized Vehicle Routing Approach for Printed Circuit Board Assembly Optimization

    ERIC Educational Resources Information Center

    Seth, Anupam

    2009-01-01

    Production planning and scheduling for printed circuit, board assembly has so far defied standard operations research approaches due to the size and complexity of the underlying problems, resulting in unexploited automation flexibility. In this thesis, the increasingly popular collect-and-place machine configuration is studied and the assembly…

  1. A neuronal circuit for colour vision based on rod-cone opponency.

    PubMed

    Joesch, Maximilian; Meister, Markus

    2016-04-14

    In bright light, cone-photoreceptors are active and colour vision derives from a comparison of signals in cones with different visual pigments. This comparison begins in the retina, where certain retinal ganglion cells have 'colour-opponent' visual responses-excited by light of one colour and suppressed by another colour. In dim light, rod-photoreceptors are active, but colour vision is impossible because they all use the same visual pigment. Instead, the rod signals are thought to splice into retinal circuits at various points, in synergy with the cone signals. Here we report a new circuit for colour vision that challenges these expectations. A genetically identified type of mouse retinal ganglion cell called JAMB (J-RGC), was found to have colour-opponent responses, OFF to ultraviolet (UV) light and ON to green light. Although the mouse retina contains a green-sensitive cone, the ON response instead originates in rods. Rods and cones both contribute to the response over several decades of light intensity. Remarkably, the rod signal in this circuit is antagonistic to that from cones. For rodents, this UV-green channel may play a role in social communication, as suggested by spectral measurements from the environment. In the human retina, all of the components for this circuit exist as well, and its function can explain certain experiences of colour in dim lights, such as a 'blue shift' in twilight. The discovery of this genetically defined pathway will enable new targeted studies of colour processing in the brain.

  2. Difference-Equation/Flow-Graph Circuit Analysis

    NASA Technical Reports Server (NTRS)

    Mcvey, I. M.

    1988-01-01

    Numerical technique enables rapid, approximate analyses of electronic circuits containing linear and nonlinear elements. Practiced in variety of computer languages on large and small computers; for circuits simple enough, programmable hand calculators used. Although some combinations of circuit elements make numerical solutions diverge, enables quick identification of divergence and correction of circuit models to make solutions converge.

  3. Analysis of frequency response of high power MUTC photodiodes based on photocurrent-dependent equivalent circuit model.

    PubMed

    Li, Jin; Xiong, Bing; Sun, Changzheng; Miao, Di; Luo, Yi

    2015-08-24

    A back-illuminated mesa-structure InGaAs/InP modified uni-traveling-carrier photodiode (MUTC-PD) is fabricated and its frequency response is investigated. A bandwidth of 40 GHz and a saturation photocurrent up to 33 mA are demonstrated. A photocurrent-dependent equivalent circuit model is proposed to analyze the frequency response of the high power MUTC-PDs. The influences of the space-charge screening, self-induced electric field and over-shoot effects are discussed in detail based on the model. Fitted curves obtained from the simple equivalent circuit model are found to be in good agreement with the data measured under different bias voltages and photocurrents.

  4. Benzothiadiazole-based polymer for single and double junction solar cells with high open circuit voltage.

    PubMed

    Venkatesan, Swaminathan; Ngo, Evan C; Chen, Qiliang; Dubey, Ashish; Mohammad, Lal; Adhikari, Nirmal; Mitul, Abu Farzan; Qiao, Qiquan

    2014-06-21

    Single and double junction solar cells with high open circuit voltage were fabricated using poly{thiophene-2,5-diyl-alt-[5,6-bis(dodecyloxy)benzo[c][1,2,5]thiadiazole]-4,7-diyl} (PBT-T1) blended with fullerene derivatives in different weight ratios. The role of fullerene loading on structural and morphological changes was investigated using atomic force microscopy (AFM) and X-ray diffraction (XRD). The XRD and AFM measurements showed that a higher fullerene mixing ratio led to breaking of inter-chain packing and hence resulted in smaller disordered polymer domains. When the PBT-T1:PC60BM weight ratio was 1 : 1, the polymer retained its structural order; however, large aggregated domains formed, leading to poor device performance due to low fill factor and short circuit current density. When the ratio was increased to 1 : 2 and then 1 : 3, smaller amorphous domains were observed, which improved photovoltaic performance. The 1 : 2 blending ratio was optimal due to adequate charge transport pathways giving rise to moderate short circuit current density and fill factor. Adding 1,8-diiodooctane (DIO) additive into the 1 : 2 blend films further improved both the short circuit current density and fill factor, leading to an increased efficiency to 4.5% with PC60BM and 5.65% with PC70BM. These single junction solar cells exhibited a high open circuit voltage at ∼ 0.9 V. Photo-charge extraction by linearly increasing voltage (Photo-CELIV) measurements showed the highest charge carrier mobility in the 1 : 2 film among the three ratios, which was further enhanced by introducing the DIO. The Photo-CELIV measurements with varying delay times showed significantly higher extracted charge carrier density for cells processed with DIO. Tandem devices using P3HT:IC60BA as bottom cell and PBT-T1:PC60BM as top cell exhibited a high open circuit voltage of 1.62 V with 5.2% power conversion efficiency. PMID:24844939

  5. Fractal dendrite-based electrically conductive composites for laser-scribed flexible circuits

    PubMed Central

    Yang, Cheng; Cui, Xiaoya; Zhang, Zhexu; Chiang, Sum Wai; Lin, Wei; Duan, Huan; Li, Jia; Kang, Feiyu; Wong, Ching-Ping

    2015-01-01

    Fractal metallic dendrites have been drawing more attentions recently, yet they have rarely been explored in electronic printing or packaging applications because of the great challenges in large-scale synthesis and limited understanding in such applications. Here we demonstrate a controllable synthesis of fractal Ag micro-dendrites at the hundred-gram scale. When used as the fillers for isotropically electrically conductive composites (ECCs), the unique three-dimensional fractal geometrical configuration and low-temperature sintering characteristic render the Ag micro dendrites with an ultra-low electrical percolation threshold of 0.97 vol% (8 wt%). The ultra-low percolation threshold and self-limited fusing ability may address some critical challenges in current interconnect technology for microelectronics. For example, only half of the laser-scribe energy is needed to pattern fine circuit lines printed using the present ECCs, showing great potential for wiring ultrathin circuits for high performance flexible electronics. PMID:26333352

  6. Time-reversal-symmetry breaking in circuit-QED-based photon lattices

    SciTech Connect

    Koch, Jens; Le Hur, Karyn; Girvin, S. M.; Houck, Andrew A.

    2010-10-15

    Breaking time-reversal symmetry is a prerequisite for accessing certain interesting many-body states such as fractional quantum Hall states. For polaritons, charge neutrality prevents magnetic fields from providing a direct symmetry-breaking mechanism and, similar to the situation in ultracold atomic gases, an effective magnetic field has to be synthesized. We show that in the circuit-QED architecture, this can be achieved by inserting simple superconducting circuits into the resonator junctions. In the presence of such coupling elements, constant parallel magnetic and electric fields suffice to break time-reversal symmetry. We support these theoretical predictions with numerical simulations for realistic sample parameters, specify general conditions under which time reversal is broken, and discuss the application to chiral Fock-state transfer, an on-chip circulator, and tunable band structure for the Kagome lattice.

  7. Genetic circuit design automation.

    PubMed

    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.

  8. Genetic circuit design automation.

    PubMed

    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

  9. A neuronal circuit for colour vision based on rod-cone opponency.

    PubMed

    Joesch, Maximilian; Meister, Markus

    2016-04-14

    In bright light, cone-photoreceptors are active and colour vision derives from a comparison of signals in cones with different visual pigments. This comparison begins in the retina, where certain retinal ganglion cells have 'colour-opponent' visual responses-excited by light of one colour and suppressed by another colour. In dim light, rod-photoreceptors are active, but colour vision is impossible because they all use the same visual pigment. Instead, the rod signals are thought to splice into retinal circuits at various points, in synergy with the cone signals. Here we report a new circuit for colour vision that challenges these expectations. A genetically identified type of mouse retinal ganglion cell called JAMB (J-RGC), was found to have colour-opponent responses, OFF to ultraviolet (UV) light and ON to green light. Although the mouse retina contains a green-sensitive cone, the ON response instead originates in rods. Rods and cones both contribute to the response over several decades of light intensity. Remarkably, the rod signal in this circuit is antagonistic to that from cones. For rodents, this UV-green channel may play a role in social communication, as suggested by spectral measurements from the environment. In the human retina, all of the components for this circuit exist as well, and its function can explain certain experiences of colour in dim lights, such as a 'blue shift' in twilight. The discovery of this genetically defined pathway will enable new targeted studies of colour processing in the brain. PMID:27049951

  10. An expert-based model for selecting the most suitable substrate material type for antenna circuits

    NASA Astrophysics Data System (ADS)

    AL-Oqla, Faris M.; Omar, Amjad A.

    2015-06-01

    Quality and properties of microwave circuits depend on all the circuit components. One of these components is the substrate. The process of substrate material selection is a decision-making problem that involves multicriteria with objectives that are diverse and conflicting. The aim of this work was to select the most suitable substrate material type to be used in antennas in the microwave frequency range that gives best performance and reliability of the substrate. For this purpose, a model was built to ease the decision-making that includes hierarchical alternatives and criteria. The substrate material type options considered were limited to fiberglass-reinforced epoxy laminates (FR4 εr = 4.8), aluminium (III) oxide (alumina εr = 9.6), gallium arsenide III-V compound (GaAs εr = 12.8) and PTFE composites reinforced with glass microfibers (Duroid εr = 2.2-2.3). To assist in building the model and making decisions, the analytical hierarchy process (AHP) was used. The decision-making process revealed that alumina substrate material type was the most suitable choice for the antennas in the microwave frequency range that yields best performance and reliability. In addition, both the size of the circuit and the loss tangent of the substrates were found to be the most contributing subfactors in the antenna circuit specifications criterion. Experimental assessments were conducted utilising The Expert Choice™ software. The judgments were tested and found to be precise, consistent and justifiable, and the marginal inconsistency values were found to be very narrow. A sensitivity analysis was also presented to demonstrate the confidence in the drawn conclusions.

  11. Entanglement genesis by ancilla-based parity measurement in 2D circuit QED.

    PubMed

    Saira, O-P; Groen, J P; Cramer, J; Meretska, M; de Lange, G; DiCarlo, L

    2014-02-21

    We present an indirect two-qubit parity meter in planar circuit quantum electrodynamics, realized by discrete interaction with an ancilla and a subsequent projective ancilla measurement with a dedicated, dispersively coupled resonator. Quantum process tomography and successful entanglement by measurement demonstrate that the meter is intrinsically quantum nondemolition. Separate interaction and measurement steps allow the execution of subsequent data-qubit operations in parallel with ancilla measurement, offering time savings over continuous schemes.

  12. Fast Fabrication of Flexible Functional Circuits Based on Liquid Metal Dual-Trans Printing.

    PubMed

    Wang, Qian; Yu, Yang; Yang, Jun; Liu, Jing

    2015-11-25

    A dual-trans method to print the first functional liquid-metal circuit layout on poly(vinyl chloride) film, and then transfer it into a poly(dimethylsiloxane) substrate through freeze phase transition processing for the fabrication of a flexible electronic device. A programmable soft electronic band and a temperature-sensing module wirelessly communicate with a mobile phone, demonstrating the efficiency and capability of the method.

  13. SEM-contour shape analysis based on circuit structure for advanced systematic defect inspection

    NASA Astrophysics Data System (ADS)

    Toyoda, Yasutaka; Shindo, Hiroyuki; Hojo, Yutaka; Fuchimoto, Daisuke

    2014-04-01

    We have developed a practicable measurement technique that can help to achieve reliable inspections for systematic defects in advanced semiconductor devices. Systematic defects occurring in the design and mask processes are a dominant component of integrated circuit yield loss in nano-scaled technologies. Therefore, it is essential to ensure systematic defects are detected at an early stage of wafer fabrication. In the past, printed pattern shapes have been evaluated by human eyes or by taking manual critical dimension (CD) measurements. However, these operations are sometimes unstable and inaccurate. Last year, we proposed a new technique for taking measurements by using a SEM contour [1]. This technique enables a highly precise quantification of various complex 2D shaped patterns by comparing a contour extracted from a SEM image using a CD measurement algorithm and an ideal pattern. We improved this technique to enable the carrying out of inspections suitable for every pattern structure required for minimizing the process margin. This technique quantifies a pattern shape of a target-layer pattern using information on a multi-layered circuit structure. This enabled it to confirm the existence of a critical defect in a circuit connecting upper/lower-layers. This paper describes the improved technique and the evaluation results obtained in evaluating it in detail.

  14. Modeling for infrared readout integrated circuit based on Verilog-A

    NASA Astrophysics Data System (ADS)

    Wang, Xiao; Shi, Zelin

    2015-04-01

    Infrared detectors are the core of infrared imaging systems, while readout integrated circuits are the key components of detectors. In order to grasp the performance of circuits quickly and accurately, a method of circuit modeling using Verilog-A language is proposed, which present a behavioral simulation model for the ROIC. At first, a typical capacitor trans-impedance amplifier(CTIA) ROIC unit is showed, then the two essential parts of it,operational amplifier and switch are modeled on behavioral level. The op amp model concludes these non-ideal factors, such as finite gain-bandwidth product, input and output offset, output resistance and so on. Non-deal factors that affect switches are considered in the switch behavioral model, such as rise and fall time, on-resistance and so on. At last time-domain modeling method for noise is presented, which is compared with the classical frequency domain method for difference. The analysis results shows that in the situation that noise interested bandwidth(NIBW) is more than 5MHz, the difference between the two methods leads to less than 1% if the sample rate of noise is larger 4 times of the NIBW

  15. A BiCMOS time interval digitizer based on fully-differential, current-steering circuits

    SciTech Connect

    Loinaz, M.J.; Wooley, B.A. . Center for Integrated Systems)

    1994-06-01

    A time interval digitizer cell with a 0--16 ns input range and a nominal LSB width of 1.0 ns has been integrated in a 2-[mu]m BiCMOS technology. The circuit exhibits both integral and differential nonlinearity below 0.15 LSB and a timing error of 0.32 ns RMS. Logic gate propagation delays are used as time measurement units, and the nominal value of the delays is set by an on-chip phase-locked loop (PLL). Fully-differential, current-steering circuits with low voltage swings are used to implement the time interval digitizer so as to generate minimal switching noise. The cell is to be used in the monolithic, multi-channel realization of a high-sensitivity, mixed-signal data acquisition front-end. By virtue of the time digitization architecture used, the average power dissipation of the cell is only 19.8 mW, despite the use of circuits that dissipate static power, and the layout area is a compact 448 [mu]m x 634 [mu]m.

  16. Organic integrated circuits for information storage based on ambipolar polymers and charge injection engineering

    NASA Astrophysics Data System (ADS)

    Dell'Erba, Giorgio; Luzio, Alessandro; Natali, Dario; Kim, Juhwan; Khim, Dongyoon; Kim, Dong-Yu; Noh, Yong-Young; Caironi, Mario

    2014-04-01

    Ambipolar semiconducting polymers, characterized by both high electron (μe) and hole (μh) mobility, offer the advantage of realizing complex complementary electronic circuits with a single semiconducting layer, deposited by simple coating techniques. However, to achieve complementarity, one of the two conduction paths in transistors has to be suppressed, resulting in unipolar devices. Here, we adopt charge injection engineering through a specific interlayer in order to tune injection into frontier energy orbitals of a high mobility donor-acceptor co-polymer. Starting from field-effect transistors with Au contacts, showing a p-type unbalanced behaviour with μh = 0.29 cm2/V s and μe = 0.001 cm2/V s, through the insertion of a caesium salt interlayer with optimized thickness, we obtain an n-type unbalanced transistor with μe = 0.12 cm2/V s and μh = 8 × 10-4 cm2/V s. We applied this result to the development of the basic pass-transistor logic building blocks such as inverters, with high gain and good noise margin, and transmission-gates. In addition, we developed and characterized information storage circuits like D-Latches and D-Flip-Flops consisting of 16 transistors, demonstrating both their static and dynamic performances and thus the suitability of this technology for more complex circuits such as display addressing logic.

  17. Equivalent circuit-based analysis of CMUT cell dynamics in arrays.

    PubMed

    Oguz, H K; Atalar, Abdullah; Köymen, Hayrettin

    2013-05-01

    Capacitive micromachined ultrasonic transducers (CMUTs) are usually composed of large arrays of closely packed cells. In this work, we use an equivalent circuit model to analyze CMUT arrays with multiple cells. We study the effects of mutual acoustic interactions through the immersion medium caused by the pressure field generated by each cell acting upon the others. To do this, all the cells in the array are coupled through a radiation impedance matrix at their acoustic terminals. An accurate approximation for the mutual radiation impedance is defined between two circular cells, which can be used in large arrays to reduce computational complexity. Hence, a performance analysis of CMUT arrays can be accurately done with a circuit simulator. By using the proposed model, one can very rapidly obtain the linear frequency and nonlinear transient responses of arrays with an arbitrary number of CMUT cells. We performed several finite element method (FEM) simulations for arrays with small numbers of cells and showed that the results are very similar to those obtained by the equivalent circuit model.

  18. Promoters Architecture-Based Mechanism for Noise-Induced Oscillations in a Single-Gene Circuit.

    PubMed

    Guisoni, N; Monteoliva, D; Diambra, L

    2016-01-01

    It is well known that single-gene circuits with negative feedback loop can lead to oscillatory gene expression when they operate with time delay. In order to generate these oscillations many processes can contribute to properly timing such delay. Here we show that the time delay coming from the transitions between internal states of the cis-regulatory system (CRS) can drive sustained oscillations in an auto-repressive single-gene circuit operating in a small volume like a cell. We found that the cooperative binding of repressor molecules is not mandatory for a oscillatory behavior if there are enough binding sites in the CRS. These oscillations depend on an adequate balance between the CRS kinetic, and the synthesis/degradation rates of repressor molecules. This finding suggest that the multi-site CRS architecture can play a key role for oscillatory behavior of gene expression. Finally, our results can also help to synthetic biologists on the design of the promoters architecture for new genetic oscillatory circuits.

  19. Promoters Architecture-Based Mechanism for Noise-Induced Oscillations in a Single-Gene Circuit

    PubMed Central

    Guisoni, N.; Monteoliva, D.; Diambra, L.

    2016-01-01

    It is well known that single-gene circuits with negative feedback loop can lead to oscillatory gene expression when they operate with time delay. In order to generate these oscillations many processes can contribute to properly timing such delay. Here we show that the time delay coming from the transitions between internal states of the cis-regulatory system (CRS) can drive sustained oscillations in an auto-repressive single-gene circuit operating in a small volume like a cell. We found that the cooperative binding of repressor molecules is not mandatory for a oscillatory behavior if there are enough binding sites in the CRS. These oscillations depend on an adequate balance between the CRS kinetic, and the synthesis/degradation rates of repressor molecules. This finding suggest that the multi-site CRS architecture can play a key role for oscillatory behavior of gene expression. Finally, our results can also help to synthetic biologists on the design of the promoters architecture for new genetic oscillatory circuits. PMID:26958852

  20. Phase control circuits using frequency multiplications for phased array antennas

    NASA Technical Reports Server (NTRS)

    Mailloux, R. J.; Caron, P. R. (Inventor)

    1973-01-01

    A phase control coupling circuit for use with a phased array antenna is described. The coupling circuit includes a combining circuit which is coupled to a transmission line, a frequency multiplier circuit which is coupled to the combining circuit, and a recombining circuit which is coupled between the frequency multiplier circuit and phased array antenna elements. In a doubler embodiment, the frequency multiplier circuit comprises frequency doublers and the combining and recombining circuits comprise four-port hybrid power dividers. In a generalized embodiment, the multiplier circuit comprises frequency multiplier elements which multiply to the Nth power, the combining circuit comprises four-part hybrid power dividers, and the recombinding circuit comprises summing circuits.

  1. GATING CIRCUITS

    DOEpatents

    Merrill, L.C.

    1958-10-14

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

  2. MULTIPLIER CIRCUIT

    DOEpatents

    Thomas, R.E.

    1959-01-20

    An electronic circuit is presented for automatically computing the product of two selected variables by multiplying the voltage pulses proportional to the variables. The multiplier circuit has a plurality of parallel resistors of predetermined values connected through separate gate circults between a first input and the output terminal. One voltage pulse is applied to thc flrst input while the second voltage pulse is applied to control circuitry for the respective gate circuits. Thc magnitude of the second voltage pulse selects the resistors upon which the first voltage pulse is imprcssed, whereby the resultant output voltage is proportional to the product of the input voltage pulses

  3. Energy-efficient STDP-based learning circuits with memristor synapses

    NASA Astrophysics Data System (ADS)

    Wu, Xinyu; Saxena, Vishal; Campbell, Kristy A.

    2014-05-01

    It is now accepted that the traditional von Neumann architecture, with processor and memory separation, is ill suited to process parallel data streams which a mammalian brain can efficiently handle. Moreover, researchers now envision computing architectures which enable cognitive processing of massive amounts of data by identifying spatio-temporal relationships in real-time and solving complex pattern recognition problems. Memristor cross-point arrays, integrated with standard CMOS technology, are expected to result in massively parallel and low-power Neuromorphic computing architectures. Recently, significant progress has been made in spiking neural networks (SNN) which emulate data processing in the cortical brain. These architectures comprise of a dense network of neurons and the synapses formed between the axons and dendrites. Further, unsupervised or supervised competitive learning schemes are being investigated for global training of the network. In contrast to a software implementation, hardware realization of these networks requires massive circuit overhead for addressing and individually updating network weights. Instead, we employ bio-inspired learning rules such as the spike-timing-dependent plasticity (STDP) to efficiently update the network weights locally. To realize SNNs on a chip, we propose to use densely integrating mixed-signal integrate-andfire neurons (IFNs) and cross-point arrays of memristors in back-end-of-the-line (BEOL) of CMOS chips. Novel IFN circuits have been designed to drive memristive synapses in parallel while maintaining overall power efficiency (<1 pJ/spike/synapse), even at spike rate greater than 10 MHz. We present circuit design details and simulation results of the IFN with memristor synapses, its response to incoming spike trains and STDP learning characterization.

  4. Organic integrated circuits for information storage based on ambipolar polymers and charge injection engineering

    SciTech Connect

    Dell'Erba, Giorgio; Natali, Dario; Luzio, Alessandro; Caironi, Mario E-mail: yynoh@dongguk.edu; Noh, Yong-Young E-mail: yynoh@dongguk.edu

    2014-04-14

    Ambipolar semiconducting polymers, characterized by both high electron (μ{sub e}) and hole (μ{sub h}) mobility, offer the advantage of realizing complex complementary electronic circuits with a single semiconducting layer, deposited by simple coating techniques. However, to achieve complementarity, one of the two conduction paths in transistors has to be suppressed, resulting in unipolar devices. Here, we adopt charge injection engineering through a specific interlayer in order to tune injection into frontier energy orbitals of a high mobility donor-acceptor co-polymer. Starting from field-effect transistors with Au contacts, showing a p-type unbalanced behaviour with μ{sub h} = 0.29 cm{sup 2}/V s and μ{sub e} = 0.001 cm{sup 2}/V s, through the insertion of a caesium salt interlayer with optimized thickness, we obtain an n-type unbalanced transistor with μ{sub e} = 0.12 cm{sup 2}/V s and μ{sub h} = 8 × 10{sup −4} cm{sup 2}/V s. We applied this result to the development of the basic pass-transistor logic building blocks such as inverters, with high gain and good noise margin, and transmission-gates. In addition, we developed and characterized information storage circuits like D-Latches and D-Flip-Flops consisting of 16 transistors, demonstrating both their static and dynamic performances and thus the suitability of this technology for more complex circuits such as display addressing logic.

  5. VO II-based microbolometer uncooled infrared focal plane arrays with CMOS readout integrated circuit

    NASA Astrophysics Data System (ADS)

    Chen, Xiqu; Yi, Xinjian

    2005-11-01

    Thin films of vanadium dioxide (VO II) were selected for microbolometers. The thin films were fabricated with a novel method mainly including ion-sputtering and annealing. It is found that the electrical properties of these thin films can be controlled by adjusting the time of ion-sputtering and annealing. A standard microbolometer pixel structure of micro-bridge has been applied. Two-dimensional arrays of microbolometers have been fabricated on silicon integrated circuit wafers using a surface micromachining technique. A new type of on-chip readout integrated circuit (ROIC) for 32×32 pixel bolometric detector arrays has been designed and fabricated using a 1.5μm double metal poly complementary metal oxide semiconductor (CMOS) processing. The readout circuit consists of three stages, which provides low noise, a highly stable detector bias, high photon current injection efficiency, high gain, and high speed. Several prototypes of 32×32 pixel bolometric detector arrays have been designed and fabricated. These arrays consist of detectors with lateral dimensions of 50μm 50μm, and each bolometric detector is on a 100μm pitch. The results of measurement show that the fabricated uncooled infrared focal plane arrays (UIRFPAs) have excellent performance. The frame rate is 50Hz, the pixel operability is above 96%, the responsivity (R) @ f/1 value is up to 15000V/W, the noise equivalent temperature difference (NETD) @ f/1 and 30Hz is about 50mK, and the average power dissipation is only 24.7mW. The results indicate that the technology of fabricating these 32×32 UIRFPAs has potential to be utilized for fabricating low cost and large-scale UIRFPAs.

  6. Soft Anisotropic Conductors as Electric Vias for Ga-Based Liquid Metal Circuits.

    PubMed

    Lu, Tong; Wissman, James; Ruthika; Majidi, Carmel

    2015-12-01

    We introduce a method for sealing liquid metal (LM) circuits with soft anisotropic conductors that prevent leaking, while simultaneously allowing for electrical contact with skin and surface mounted electronics. These films are composed of polydimethylsiloxane (PDMS) embedded with vertically aligned columns of ferromagnetic Ag-Ni microparticles. The microparticles are magnetically aligned and support electrical conductivity only through the thickness (z-axis) of the elastomer film. Measurements on 10-40% (by wt) composites show moderate volumetric resistivity (as low as ρ = 0.03 Ω/m) through the thickness and no conductivity between adjacent traces. Functionality is demonstrated with several illustrative applications related to tactile sensing and electronics hardware integration.

  7. Printed dose-recording tag based on organic complementary circuits and ferroelectric nonvolatile memories

    PubMed Central

    Nga Ng, Tse; Schwartz, David E.; Mei, Ping; Krusor, Brent; Kor, Sivkheng; Veres, Janos; Bröms, Per; Eriksson, Torbjörn; Wang, Yong; Hagel, Olle; Karlsson, Christer

    2015-01-01

    We have demonstrated a printed electronic tag that monitors time-integrated sensor signals and writes to nonvolatile memories for later readout. The tag is additively fabricated on flexible plastic foil and comprises a thermistor divider, complementary organic circuits, and two nonvolatile memory cells. With a supply voltage below 30 V, the threshold temperatures can be tuned between 0 °C and 80 °C. The time-temperature dose measurement is calibrated for minute-scale integration. The two memory bits are sequentially written in a thermometer code to provide an accumulated dose record. PMID:26307438

  8. TRIPPING CIRCUIT

    DOEpatents

    Lees, G.W.; McCormick, E.D.

    1962-05-22

    A tripping circuit employing a magnetic amplifier for tripping a reactor in response to power level, period, or instrument failure is described. A reference winding and signal winding are wound in opposite directions on the core. Current from an ion chamber passes through both windings. If the current increases at too fast a rate, a shunt circuit bypasses one or the windings and the amplifier output reverses polarity. (AEC)

  9. Radio Frequency Transistors and Circuits Based on CVD MoS2.

    PubMed

    Sanne, Atresh; Ghosh, Rudresh; Rai, Amritesh; Yogeesh, Maruthi Nagavalli; Shin, Seung Heon; Sharma, Ankit; Jarvis, Karalee; Mathew, Leo; Rao, Rajesh; Akinwande, Deji; Banerjee, Sanjay

    2015-08-12

    We report on the gigahertz radio frequency (RF) performance of chemical vapor deposited (CVD) monolayer MoS2 field-effect transistors (FETs). Initial DC characterizations of fabricated MoS2 FETs yielded current densities exceeding 200 μA/μm and maximum transconductance of 38 μS/μm. A contact resistance corrected low-field mobility of 55 cm(2)/(V s) was achieved. Radio frequency FETs were fabricated in the ground-signal-ground (GSG) layout, and standard de-embedding techniques were applied. Operating at the peak transconductance, we obtain short-circuit current-gain intrinsic cutoff frequency, fT, of 6.7 GHz and maximum intrinsic oscillation frequency, fmax, of 5.3 GHz for a device with a gate length of 250 nm. The MoS2 device afforded an extrinsic voltage gain Av of 6 dB at 100 MHz with voltage amplification until 3 GHz. With the as-measured frequency performance of CVD MoS2, we provide the first demonstration of a common-source (CS) amplifier with voltage gain of 14 dB and an active frequency mixer with conversion gain of -15 dB. Our results of gigahertz frequency performance as well as analog circuit operation show that large area CVD MoS2 may be suitable for industrial-scale electronic applications. PMID:26134588

  10. Mode converter based on an inverse taper for multimode silicon nanophotonic integrated circuits.

    PubMed

    Dai, Daoxin; Mao, Mao

    2015-11-01

    An inverse taper on silicon is proposed and designed to realize an efficient mode converter available for the connection between multimode silicon nanophotonic integrated circuits and few-mode fibers. The present mode converter has a silicon-on-insulator inverse taper buried in a 3 × 3μm(2) SiN strip waveguide to deal with not only for the fundamental mode but also for the higher-order modes. The designed inverse taper enables the conversion between the six modes (i.e., TE(11), TE(21), TE(31), TE(41), TM(11), TM(12)) in a 1.4 × 0.22μm(2) multimode SOI waveguide and the six modes (like the LP(01), LP(11a), LP(11b) modes in a few-mode fiber) in a 3 × 3μm(2) SiN strip waveguide. The conversion efficiency for any desired mode is higher than 95.6% while any undesired mode excitation ratio is lower than 0.5%. This is helpful to make multimode silicon nanophotonic integrated circuits (e.g., the on-chip mode (de)multiplexers developed well) available to work together with few-mode fibers in the future.

  11. Mode converter based on an inverse taper for multimode silicon nanophotonic integrated circuits.

    PubMed

    Dai, Daoxin; Mao, Mao

    2015-11-01

    An inverse taper on silicon is proposed and designed to realize an efficient mode converter available for the connection between multimode silicon nanophotonic integrated circuits and few-mode fibers. The present mode converter has a silicon-on-insulator inverse taper buried in a 3 × 3μm(2) SiN strip waveguide to deal with not only for the fundamental mode but also for the higher-order modes. The designed inverse taper enables the conversion between the six modes (i.e., TE(11), TE(21), TE(31), TE(41), TM(11), TM(12)) in a 1.4 × 0.22μm(2) multimode SOI waveguide and the six modes (like the LP(01), LP(11a), LP(11b) modes in a few-mode fiber) in a 3 × 3μm(2) SiN strip waveguide. The conversion efficiency for any desired mode is higher than 95.6% while any undesired mode excitation ratio is lower than 0.5%. This is helpful to make multimode silicon nanophotonic integrated circuits (e.g., the on-chip mode (de)multiplexers developed well) available to work together with few-mode fibers in the future. PMID:26561108

  12. Commercialisation of CMOS Integrated Circuit Technology in Multi-Electrode Arrays for Neuroscience and Cell-Based Biosensors

    PubMed Central

    Graham, Anthony H. D.; Robbins, Jon; Bowen, Chris R.; Taylor, John

    2011-01-01

    The adaptation of standard integrated circuit (IC) technology as a transducer in cell-based biosensors in drug discovery pharmacology, neural interface systems and electrophysiology requires electrodes that are electrochemically stable, biocompatible and affordable. Unfortunately, the ubiquitous Complementary Metal Oxide Semiconductor (CMOS) IC technology does not meet the first of these requirements. For devices intended only for research, modification of CMOS by post-processing using cleanroom facilities has been achieved. However, to enable adoption of CMOS as a basis for commercial biosensors, the economies of scale of CMOS fabrication must be maintained by using only low-cost post-processing techniques. This review highlights the methodologies employed in cell-based biosensor design where CMOS-based integrated circuits (ICs) form an integral part of the transducer system. Particular emphasis will be placed on the application of multi-electrode arrays for in vitro neuroscience applications. Identifying suitable IC packaging methods presents further significant challenges when considering specific applications. The various challenges and difficulties are reviewed and some potential solutions are presented. PMID:22163884

  13. Commercialisation of CMOS integrated circuit technology in multi-electrode arrays for neuroscience and cell-based biosensors.

    PubMed

    Graham, Anthony H D; Robbins, Jon; Bowen, Chris R; Taylor, John

    2011-01-01

    The adaptation of standard integrated circuit (IC) technology as a transducer in cell-based biosensors in drug discovery pharmacology, neural interface systems and electrophysiology requires electrodes that are electrochemically stable, biocompatible and affordable. Unfortunately, the ubiquitous Complementary Metal Oxide Semiconductor (CMOS) IC technology does not meet the first of these requirements. For devices intended only for research, modification of CMOS by post-processing using cleanroom facilities has been achieved. However, to enable adoption of CMOS as a basis for commercial biosensors, the economies of scale of CMOS fabrication must be maintained by using only low-cost post-processing techniques. This review highlights the methodologies employed in cell-based biosensor design where CMOS-based integrated circuits (ICs) form an integral part of the transducer system. Particular emphasis will be placed on the application of multi-electrode arrays for in vitro neuroscience applications. Identifying suitable IC packaging methods presents further significant challenges when considering specific applications. The various challenges and difficulties are reviewed and some potential solutions are presented.

  14. Strip biosensor for amplified detection of nerve growth factor-beta based on a molecular translator and catalytic DNA circuit.

    PubMed

    Liu, Jun; Lai, Ting; Mu, Kejie; Zhou, Zheng

    2014-10-01

    We have demonstrated a new visual detection approach based on a molecular translator and a catalytic DNA circuit for the detection of nerve growth factor-beta (NGF-β). In this assay, a molecular translator based on the binding-induced DNA strand-displacement reaction was employed to convert the input protein to an output DNA signal. The molecular translator is composed of a target recognition element and a signal output element. Target recognition is achieved by the binding of the anti-NGF-β antibody to the target protein. Polyclonal anti-NGF-β antibody is conjugated to DNA1 and DNA2. The antibody conjugated DNA1 is initially hybridized to DNA3 to form a stable DNA1/DNA3 duplex. In the presence of NGF-β, the binding of the same target protein brings DNA1 and DNA2 into close proximity, resulting in an increase in their local effective concentration. This process triggers the strand-displacement reaction between DNA2 and DNA3 and releases the output DNA3. The released DNA3 is further amplified by a catalytic DNA circuit. The product of the catalytic DNA circuit is detected by a strip biosensor. This proposed assay has high sensitivity and selectivity with a dynamic response ranging from 10 fM to 10 pM, and its detection limit is 10 fM of NGF-β. This work provides a sensitive, enzyme-free, and universal strategy for the detection of other proteins. PMID:25068151

  15. Addressable-Matrix Integrated-Circuit Test Structure

    NASA Technical Reports Server (NTRS)

    Sayah, Hoshyar R.; Buehler, Martin G.

    1991-01-01

    Method of quality control based on use of row- and column-addressable test structure speeds collection of data on widths of resistor lines and coverage of steps in integrated circuits. By use of straightforward mathematical model, line widths and step coverages deduced from measurements of electrical resistances in each of various combinations of lines, steps, and bridges addressable in test structure. Intended for use in evaluating processes and equipment used in manufacture of application-specific integrated circuits.

  16. Rocket Based Combined Cycle (RBCC) Propulsion Workshop, volume 2

    NASA Technical Reports Server (NTRS)

    Chojnacki, Kent T.

    1992-01-01

    The goal of the Rocket Based Combined Cycle (RBCC) Propulsion Technology Workshop, was to impart technology information to the propulsion community with respect to hypersonic combined cycle propulsion capabilities. The major recommendation resulting from this technology workshop was as follows: conduct a systems-level applications study to define the desired propulsion system and vehicle technology requirements for LEO launch vehicles. All SSTO and TSTO options using the various propulsion systems (airbreathing combined cycle, rocket-based combined cycle, and all rocket) must be considered. Such a study should be accomplished as soon as possible. It must be conducted with a consistent set of ground rules and assumptions. Additionally, the study should be conducted before any major expenditures on a RBCC technology development program occur.

  17. Note: Printed circuit board based electrically triggered compact rail gap switch

    NASA Astrophysics Data System (ADS)

    Saxena, A. K.; Kaushik, T. C.; Goswami, M. P.; Gupta, Satish C.

    2010-05-01

    An electrically triggered rail gap switch has been designed over a commercially available copper clad fiberglass sheet commonly used in making printed circuit boards for applications requiring compact design and direct integration to parallel plate transmission lines. Switch performance has been investigated in terms of its inductance, jitter, and gap closing time. With an electrode separation of 9.0 mm, it has been found to have an inductance of 6 nH, gap closing time of 5 ns, and jitter of about 4-10 ns measured at 95% of self-breakdown voltage. An application of this switch has been demonstrated as an electrically exploding foil accelerator developed over the same board and velocities up to 1.6 km/s have been achieved on Kapton flyers with diameter of 3.0 mm and thickness of 125 μm using a compact 1 μF capacitor bank.

  18. Water-soluble thin film transistors and circuits based on amorphous indium-gallium-zinc oxide.

    PubMed

    Jin, Sung Hun; Kang, Seung-Kyun; Cho, In-Tak; Han, Sang Youn; Chung, Ha Uk; Lee, Dong Joon; Shin, Jongmin; Baek, Geun Woo; Kim, Tae-il; Lee, Jong-Ho; Rogers, John A

    2015-04-22

    This paper presents device designs, circuit demonstrations, and dissolution kinetics for amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistors (TFTs) comprised completely of water-soluble materials, including SiNx, SiOx, molybdenum, and poly(vinyl alcohol) (PVA). Collections of these types of physically transient a-IGZO TFTs and 5-stage ring oscillators (ROs), constructed with them, show field effect mobilities (∼10 cm2/Vs), on/off ratios (∼2×10(6)), subthreshold slopes (∼220 mV/dec), Ohmic contact properties, and oscillation frequency of 5.67 kHz at supply voltages of 19 V, all comparable to otherwise similar devices constructed in conventional ways with standard, nontransient materials. Studies of dissolution kinetics for a-IGZO films in deionized water, bovine serum, and phosphate buffer saline solution provide data of relevance for the potential use of these materials and this technology in temporary biomedical implants.

  19. Spinal locomotor circuits develop using hierarchical rules based on motorneuron position and identity

    PubMed Central

    Hinckley, Christopher A.; Alaynick, William A.; Gallarda, Benjamin W.; Hayashi, Marito; Hilde, Kathryn L.; Driscoll, Shawn P.; Dekker, Joseph D.; Tucker, Haley O.; Sharpee, Tatyana O.; Pfaff, Samuel L.

    2015-01-01

    Summary The coordination of multi-muscle movements originates in the circuitry that regulates the firing patterns of spinal motorneurons. Sensory neurons rely on the musculotopic organization of motorneurons to establish orderly connections, prompting us to examine whether the intraspinal circuitry that coordinates motor activity likewise uses cell position as an internal wiring reference. We generated a motorneuron-specific GCaMP6f mouse line and employed two-photon imaging to monitor the activity of lumbar motorneurons. We show that the central pattern generator neural network coordinately drives rhythmic columnar-specific motorneuron bursts at distinct phases of the locomotor cycle. Using multiple genetic strategies to perturb the subtype identity and orderly position of motorneurons, we found that neurons retained their rhythmic activity - but cell position was decoupled from the normal phasing pattern underlying flexion and extension. These findings suggest a hierarchical basis of motor circuit formation that relies on increasingly stringent matching of neuronal identity and position. PMID:26335645

  20. Note: Printed circuit board based electrically triggered compact rail gap switch.

    PubMed

    Saxena, A K; Kaushik, T C; Goswami, M P; Gupta, Satish C

    2010-05-01

    An electrically triggered rail gap switch has been designed over a commercially available copper clad fiberglass sheet commonly used in making printed circuit boards for applications requiring compact design and direct integration to parallel plate transmission lines. Switch performance has been investigated in terms of its inductance, jitter, and gap closing time. With an electrode separation of 9.0 mm, it has been found to have an inductance of 6 nH, gap closing time of 5 ns, and jitter of about 4-10 ns measured at 95% of self-breakdown voltage. An application of this switch has been demonstrated as an electrically exploding foil accelerator developed over the same board and velocities up to 1.6 km/s have been achieved on Kapton flyers with diameter of 3.0 mm and thickness of 125 microm using a compact 1 microF capacitor bank. PMID:20515183

  1. Nanoparticle-Based Combination Therapy for Cancer Treatment.

    PubMed

    Yhee, Ji Young; Son, Sejin; Lee, Hyukjin; Kim, Kwangmeyung

    2015-01-01

    In recent years, combination of different types of therapies using nanoparticles has emerged as an advanced strategy for cancer treatment. Most of all, combination of chemotherapeutic drug and siRNA in nanoformulation has shown a great potential, because siRNA-mediated specific gene silencing can compensate for the incomplete anti-cancer actions of chemotherapy. In this article, nanoparticle-based combination therapy for cancer treatment is introduced to be focused on the therapeutic chemical and siRNA combination. It is classified into 3 groups: 1) general chemotherapy combined with siRNA carrying nanoparticle, 2) co-delivery of chemical and siRNA therapeutics within a single nanoparticle, and 3) Use of multiple nanoparticles for chemical and siRNA therapeutics. The purpose of the combination and the mechanisms of anti-cancer action was described according to the categories. Examples of some recent developments of nanotechnology-based chemo- and siRNA- therapeutics combination therapy are summarized for better understanding of its practical application.

  2. Implementation of sequential logic circuits using the Mach-Zehnder interferometer structure based on electro-optic effect

    NASA Astrophysics Data System (ADS)

    Kumar Raghuwanshi, Sanjeev; Kumar, Ajay; Chen, Nan-Kuang

    2014-12-01

    The electro-optic effect is one of the most important phenomena in Mach-Zehnder (MZI) interferometer structure. The Mach-Zehnder interferometer structure working on the principle of electro-optic effect behaves as the powerful optical switching device. The paper contains the discussion of electro-optic effect based MZI structure. The proper feedback mechanism with the delay unit provides the responses of optical clocked D flip-flop. The paper includes the detailed mathematical description of optical clocked D flip-flops with the MATLAB simulation result. Based on the proposed optical D-flip flop, it is possible to construct some sequential circuits such as synchronous shift registers and ripple counters. Finally, the paper includes the detailed discussion of optical sequential circuits such as synchronous shift register and ripple counter and its implementation using the MATLAB simulation. However, the concept of proposed optical clocked D flip-flop is implemented using the OptiBPM software for the proper verification of the discussed schemes. The Basic building block structures are analyzed to check the optimum performance parameters such as crosstalk, power imbalance, extinction ratio and transition losses, in order to obtain the appropriate Ti-thickness and switching voltage.

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

    NASA Astrophysics Data System (ADS)

    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.

  4. CIRCUIT2. 4. 2-Stage Classification Modeling

    SciTech Connect

    Wilde, R.A. ); Anderson, J.V. )

    1987-12-01

    CIRCUIT2.4 is used to design optimum two-stage classification configurations and operating conditions for energy conservation. It permits simulation of five basic grinding-classification circuits, including one single-stage and four two-stage classification arrangements. Hydrocyclones, spiral classifiers, and sieve band screens can be simulated, and the user may choose the combination of devices for the flowsheet simulation. In addition, the user may select from four classification modeling methods to achieve the goals of a simulation project using the most familiar concepts. Circuit performance is modeled based on classification parameters or equipment operating conditions. A modular approach was taken in designing the program, which allows future addition of other models with relatively minor changes.

  5. A bit serial sequential circuit

    NASA Technical Reports Server (NTRS)

    Hu, S.; Whitaker, S.

    1990-01-01

    Normally a sequential circuit with n state variables consists of n unique hardware realizations, one for each state variable. All variables are processed in parallel. This paper introduces a new sequential circuit architecture that allows the state variables to be realized in a serial manner using only one next state logic circuit. The action of processing the state variables in a serial manner has never been addressed before. This paper presents a general design procedure for circuit construction and initialization. Utilizing pass transistors to form the combinational next state forming logic in synchronous sequential machines, a bit serial state machine can be realized with a single NMOS pass transistor network connected to shift registers. The bit serial state machine occupies less area than other realizations which perform parallel operations. Moreover, the logical circuit of the bit serial state machine can be modified by simply changing the circuit input matrix to develop an adaptive state machine.

  6. MULTIPLIER CIRCUIT

    DOEpatents

    Chase, R.L.

    1963-05-01

    An electronic fast multiplier circuit utilizing a transistor controlled voltage divider network is presented. The multiplier includes a stepped potentiometer in which solid state or transistor switches are substituted for mechanical wipers in order to obtain electronic switching that is extremely fast as compared to the usual servo-driven mechanical wipers. While this multiplier circuit operates as an approximation and in steps to obtain a voltage that is the product of two input voltages, any desired degree of accuracy can be obtained with the proper number of increments and adjustment of parameters. (AEC)

  7. A Power Conditioning Stage Based on Analog-Circuit MPPT Control and a Superbuck Converter for Thermoelectric Generators in Spacecraft Power Systems

    NASA Astrophysics Data System (ADS)

    Sun, Kai; Wu, Hongfei; Cai, Yan; Xing, Yan

    2014-06-01

    A thermoelectric generator (TEG) is a very important kind of power supply for spacecraft, especially for deep-space missions, due to its long lifetime and high reliability. To develop a practical TEG power supply for spacecraft, a power conditioning stage is indispensable, being employed to convert the varying output voltage of the TEG modules to a definite voltage for feeding batteries or loads. To enhance the system reliability, a power conditioning stage based on analog-circuit maximum-power-point tracking (MPPT) control and a superbuck converter is proposed in this paper. The input of this power conditioning stage is connected to the output of the TEG modules, and the output of this stage is connected to the battery and loads. The superbuck converter is employed as the main circuit, featuring low input current ripples and high conversion efficiency. Since for spacecraft power systems reliable operation is the key target for control circuits, a reset-set flip-flop-based analog circuit is used as the basic control circuit to implement MPPT, being much simpler than digital control circuits and offering higher reliability. Experiments have verified the feasibility and effectiveness of the proposed power conditioning stage. The results show the advantages of the proposed stage, such as maximum utilization of TEG power, small input ripples, and good stability.

  8. In vivo silicon-based flexible radio frequency integrated circuits monolithically encapsulated with biocompatible liquid crystal polymers.

    PubMed

    Hwang, Geon-Tae; Im, Donggu; Lee, Sung Eun; Lee, Jooseok; Koo, Min; Park, So Young; Kim, Seungjun; Yang, Kyounghoon; Kim, Sung June; Lee, Kwyro; Lee, Keon Jae

    2013-05-28

    Biointegrated electronics have been investigated for various healthcare applications which can introduce biomedical systems into the human body. Silicon-based semiconductors perform significant roles of nerve stimulation, signal analysis, and wireless communication in implantable electronics. However, the current large-scale integration (LSI) chips have limitations in in vivo devices due to their rigid and bulky properties. This paper describes in vivo ultrathin silicon-based liquid crystal polymer (LCP) monolithically encapsulated flexible radio frequency integrated circuits (RFICs) for medical wireless communication. The mechanical stability of the LCP encapsulation is supported by finite element analysis simulation. In vivo electrical reliability and bioaffinity of the LCP monoencapsulated RFIC devices are confirmed in rats. In vitro accelerated soak tests are performed with Arrhenius method to estimate the lifetime of LCP monoencapsulated RFICs in a live body. The work could provide an approach to flexible LSI in biointegrated electronics such as an artificial retina and wireless body sensor networks.

  9. Fabric circuit board-based dry electrode and its characteristics for long-term physiological signal recording.

    PubMed

    Yoo, Jerald; Yoo, Hoi-Jun

    2011-01-01

    This paper presents a dry fabric electrode and its characteristics. For long-term physiological signal monitoring, conventional wet type electrode such as an Ag/AgCl electrode may not be sufficient, because captured signal strength degrades over time as its electrolyte dehydrates. Moreover, the electrolyte may cause skin irritation over a period of time. As a complement, a dry electrode can be used. In this work, fabric-based dry electrodes are introduced. Planar-Fabric Circuit Board (P-FCB) technology enables low cost and uniform productions of such electrodes; electrical properties of the electrodes with various materials, sizes, and time are shown. Both the strengths and drawbacks of the fabric-based electrodes are also discussed.

  10. On-Chip Generation and Manipulation of Entangled Photons Based on Reconfigurable Lithium-Niobate Waveguide Circuits

    NASA Astrophysics Data System (ADS)

    Jin, H.; Liu, F. M.; Xu, P.; Xia, J. L.; Zhong, M. L.; Yuan, Y.; Zhou, J. W.; Gong, Y. X.; Wang, W.; Zhu, S. N.

    2014-09-01

    A consequent tendency toward high-performance quantum information processing is to develop the fully integrated photonic chip. Here, we report the on-chip generation and manipulation of entangled photons based on reconfigurable lithium-niobate waveguide circuits. By introducing a periodically poled structure into the waveguide circuits, two individual photon-pair sources with a controllable electro-optic phase shift are produced within a Hong-Ou-Mandel interferometer, resulting in a deterministically separated identical photon pair. The state is characterized by 92.9±0.9% visibility Hong-Ou-Mandel interference. The photon flux reaches ˜1.4×107 pairs nm-1 mW-1. The whole chip is designed to contain nine similar units to produce identical photon pairs spanning the telecom C and L band by the flexible engineering of nonlinearity. Our work presents a scenario for on-chip engineering of different photon sources and paves the way to fully integrated quantum technologies.

  11. Chinese Subjective Sentence Extraction Based on Dictionary and Combination Classifiers

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Zhou, Yanquan; Wang, Xin

    For extracting of Chinese subjective sentence, this paper proposes a new dictionary-based extraction method and a novel classifier combination strategy. For the first method, we use the training data to score the subjective dictionary, which was composed of indicative verb, indicative adverbs, sentiment words, interjection and punctuation. Then we use the dictionary to score the test data, and filter the sentences by setting a reasonable threshold. New classifier combination strategies base on the maximum error correction capability. To enhance the accuracy, the method improves the traditional single error correction and achieves the dual error correction both in positive and negative classes. Experimental results show that the two methods are effective .And the final results show that the combination of two ways achieves a satisfactory subjective sentence extraction performance.

  12. Current regulating circuit

    SciTech Connect

    Hoffman, Ph. A.

    1985-03-12

    A battery charger which includes terminals for connection to an electric power source, an electrical charging circuit and an operative arrangement for connecting at least one rechargeable battery cell, in series with the charging circuit across the terminals. The battery charger has a charging circuit which includes a first resistor, a second resistor, a third resistor and a rectifier, constituted by at least one diode, in series. A first transistor, which has a collector-emitter path and a base-emitter path, is operatively connected so that the base-emitter path is connected in parallel with the first resistor. A fourth resistor is provided, the fourth resistor being connected in series with the collector-emitter path of the transistor and the third resistor. A plurality of additional transistors, connected in Darlington configuration, includes a second transistor and a final transistor, each of the additional transistors having its collector connected to a circuit point between the third resistor and an electrode of the diode. The first transistor and the last transistor have their emitters connected via a current-limiting PTC fifth resistor which may act as a fuse. The first transistor and the second transistor have their respective collector and base conductively connected. The connection of the third resistor provides internal feedback. The fifth resistor, when in series with the first resistor in the base-emitter circuit, provides external feedback.

  13. Water-soluble thin film transistors and circuits based on amorphous indium-gallium-zinc oxide.

    PubMed

    Jin, Sung Hun; Kang, Seung-Kyun; Cho, In-Tak; Han, Sang Youn; Chung, Ha Uk; Lee, Dong Joon; Shin, Jongmin; Baek, Geun Woo; Kim, Tae-il; Lee, Jong-Ho; Rogers, John A

    2015-04-22

    This paper presents device designs, circuit demonstrations, and dissolution kinetics for amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistors (TFTs) comprised completely of water-soluble materials, including SiNx, SiOx, molybdenum, and poly(vinyl alcohol) (PVA). Collections of these types of physically transient a-IGZO TFTs and 5-stage ring oscillators (ROs), constructed with them, show field effect mobilities (∼10 cm2/Vs), on/off ratios (∼2×10(6)), subthreshold slopes (∼220 mV/dec), Ohmic contact properties, and oscillation frequency of 5.67 kHz at supply voltages of 19 V, all comparable to otherwise similar devices constructed in conventional ways with standard, nontransient materials. Studies of dissolution kinetics for a-IGZO films in deionized water, bovine serum, and phosphate buffer saline solution provide data of relevance for the potential use of these materials and this technology in temporary biomedical implants. PMID:25805699

  14. Combine harvester monitor system based on wireless sensor network

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A measurement method based on Wireless Sensor Network (WSN) was developed to monitor the working condition of combine harvester for remote application. Three JN5139 modules were chosen for sensor data acquisition and another two as a router and a coordinator, which could create a tree topology netwo...

  15. Architecture and algorithm of a circuit simulator

    NASA Astrophysics Data System (ADS)

    Marranghello, Norian; Damiani, Furio

    1990-11-01

    Software-based circuit simulators had a ten-fold speed improvement in the last 15 years. Despite this they are not fast enough to cost- effectively deal with current VLSI circuits. In this paper we describe the current status of the ABACUS circuit simulator project, which takes advantage of both a dedicated hardware to speed up circuit simulation and a new methodology, where each parallel processor behaves like a circuit element.

  16. Piezoelectric resonators and oscillator circuit based on higher-order out-of-plane modes for density-viscosity measurements of liquids

    NASA Astrophysics Data System (ADS)

    Toledo, J.; Manzaneque, T.; Ruiz-Díez, V.; Kucera, M.; Pfusterschmied, G.; Wistrela, E.; Schmid, U.; Sánchez-Rojas, J. L.

    2016-08-01

    We report the use of two AlN-based piezoelectric microresonators for the monitoring of density and viscosity of liquids and its application to detect lubricant oil dilution with diesel fuel. Two devices designed to resonate in the 4th-order roof tile-shaped vibration mode, but with two different anchor schemes, were fabricated and characterized. Interface circuits were designed to convert the one-port impedance into a resonant two-port transfer function. This allowed us to implement a phase locked loop (PLL)-based oscillator circuit based on the resonators, the interface circuit and a commercial lock-in amplifier. Our results demonstrate the performance of the resonators in fluids having viscosities up to 500 mPa · s. The performance of the sensors in terms of sensitivity and resolution are compared for both anchor configurations.

  17. Selecting supplier combination based on fuzzy multicriteria analysis

    NASA Astrophysics Data System (ADS)

    Han, Zhi-Qiu; Luo, Xin-Xing; Chen, Xiao-Hong; Yang, Wu-E.

    2015-07-01

    Existing multicriteria analysis (MCA) methods are probably ineffective in selecting a supplier combination. Thus, an MCA-based fuzzy 0-1 programming method is introduced. The programming relates to a simple MCA matrix that is used to select a single supplier. By solving the programming, the most feasible combination of suppliers is selected. Importantly, this result differs from selecting suppliers one by one according to a single-selection order, which is used to rank sole suppliers in existing MCA methods. An example highlights such difference and illustrates the proposed method.

  18. Microwave GaAs Integrated Circuits On Quartz Substrates

    NASA Technical Reports Server (NTRS)

    Siegel, Peter H.; Mehdi, Imran; Wilson, Barbara

    1994-01-01

    Integrated circuits for use in detecting electromagnetic radiation at millimeter and submillimeter wavelengths constructed by bonding GaAs-based integrated circuits onto quartz-substrate-based stripline circuits. Approach offers combined advantages of high-speed semiconductor active devices made only on epitaxially deposited GaAs substrates with low-dielectric-loss, mechanically rugged quartz substrates. Other potential applications include integration of antenna elements with active devices, using carrier substrates other than quartz to meet particular requirements using lifted-off GaAs layer in membrane configuration with quartz substrate supporting edges only, and using lift-off technique to fabricate ultrathin discrete devices diced separately and inserted into predefined larger circuits. In different device concept, quartz substrate utilized as transparent support for GaAs devices excited from back side by optical radiation.

  19. Development of a Mass Sensitive Quartz Crystal Microbalance (QCM)-Based DNA Biosensor Using a 50 MHz Electronic Oscillator Circuit

    PubMed Central

    García-Martinez, Gonzalo; Bustabad, Enrique Alonso; Perrot, Hubert; Gabrielli, Claude; Bucur, Bogdan; Lazerges, Mathieu; Rose, Daniel; Rodriguez-Pardo, Loreto; Fariña, Jose; Compère, Chantal; Vives, Antonio Arnau

    2011-01-01

    This work deals with the design of a high sensitivity DNA sequence detector using a 50 MHz quartz crystal microbalance (QCM) electronic oscillator circuit. The oscillator circuitry is based on Miller topology, which is able to work in damping media. Calibration and experimental study of frequency noise are carried out, finding that the designed sensor has a resolution of 7.1 ng/cm2 in dynamic conditions (with circulation of liquid). Then the oscillator is proved as DNA biosensor. Results show that the system is able to detect the presence of complementary target DNAs in a solution with high selectivity and sensitivity. DNA target concentrations higher of 50 ng/mL can be detected. PMID:22164037

  20. Energy losing rate and open-circuit voltage analysis of organic solar cells based on detailed photocurrent simulation

    SciTech Connect

    Yu Junsheng; Huang Jiang; Zhang Lei; Jiang Yadong

    2009-09-15

    The J-V characteristics and photovoltaic response of indium tin oxide/pentacene (d nm)/C{sub 60} (40 nm)/BCP (10 nm)/Ag (100 nm) devices have been systematically analyzed. By fitting the J-V characteristics of the fabricated devices, photocurrent densities J{sub ph} were obtained. Meanwhile, we proposed a modified optical transfer matrix theory to satisfy the reasonable trend between P{sub 0}R{sub 0} and film thickness of pentacene layers. Then, we revealed that an accurate rate of energy loss can be defined as E{sub loss}=1-betaJ{sub e}/P{sub 0}R{sub 0}. Also, the relationship between open-circuit voltage V{sub OC}, compensation voltage V{sub 0} and initial polaron-pair bounding energy E{sub B} was determined based on the detailed study and simulation of device photocurrent.

  1. Development of a mass sensitive quartz crystal microbalance (QCM)-based DNA biosensor using a 50 MHz electronic oscillator circuit.

    PubMed

    García-Martinez, Gonzalo; Bustabad, Enrique Alonso; Perrot, Hubert; Gabrielli, Claude; Bucur, Bogdan; Lazerges, Mathieu; Rose, Daniel; Rodriguez-Pardo, Loreto; Fariña, Jose; Compère, Chantal; Vives, Antonio Arnau

    2011-01-01

    This work deals with the design of a high sensitivity DNA sequence detector using a 50 MHz quartz crystal microbalance (QCM) electronic oscillator circuit. The oscillator circuitry is based on Miller topology, which is able to work in damping media. Calibration and experimental study of frequency noise are carried out, finding that the designed sensor has a resolution of 7.1 ng/cm(2) in dynamic conditions (with circulation of liquid). Then the oscillator is proved as DNA biosensor. Results show that the system is able to detect the presence of complementary target DNAs in a solution with high selectivity and sensitivity. DNA target concentrations higher of 50 ng/mL can be detected. PMID:22164037

  2. A High-Voltage Integrated Circuit Engine for a Dielectrophoresis-based Programmable Micro-Fluidic Processor.

    PubMed

    Current, K Wayne; Yuk, Kelvin; McConaghy, Charles; Gascoyne, Peter R C; Schwartz, Jon A; Vykoukal, Jody V; Andrews, Craig

    2005-07-24

    A high-voltage (HV) integrated circuit has been demonstrated to transport droplets on programmable paths across its coated surface. This chip is the engine for a dielectrophoresis (DEP)-based micro-fluidic lab-on-a-chip system. This chip creates DEP forces that move and help inject droplets. Electrode excitation voltage and frequency are variable. With the electrodes driven with a 100V peak-to-peak periodic waveform, the maximum high-voltage electrode waveform frequency is about 200Hz. Data communication rate is variable up to 250kHz. This demonstration chip has a 32×32 array of nominally 100V electrode drivers. It is fabricated in a 130V SOI CMOS fabrication technology, dissipates a maximum of 1.87W, and is about 10.4 mm × 8.2 mm.

  3. A High-Voltage Integrated Circuit Engine for a Dielectrophoresis-based Programmable Micro-Fluidic Processor

    PubMed Central

    Current, K. Wayne; Yuk, Kelvin; McConaghy, Charles; Gascoyne, Peter R. C.; Schwartz, Jon A.; Vykoukal, Jody V.; Andrews, Craig

    2010-01-01

    A high-voltage (HV) integrated circuit has been demonstrated to transport droplets on programmable paths across its coated surface. This chip is the engine for a dielectrophoresis (DEP)-based micro-fluidic lab-on-a-chip system. This chip creates DEP forces that move and help inject droplets. Electrode excitation voltage and frequency are variable. With the electrodes driven with a 100V peak-to-peak periodic waveform, the maximum high-voltage electrode waveform frequency is about 200Hz. Data communication rate is variable up to 250kHz. This demonstration chip has a 32×32 array of nominally 100V electrode drivers. It is fabricated in a 130V SOI CMOS fabrication technology, dissipates a maximum of 1.87W, and is about 10.4 mm × 8.2 mm. PMID:23989241

  4. Suppressing effect of calcium-based waste on control of bromine flux during the pyrolysis of printed circuit boards.

    PubMed

    Jie, Guan; Min, Xu; Wu, Wenjie; Zhang, Chenglong; Wang, Jingwei; Bai, Jianfeng

    2012-11-01

    The effect of calcium-based addition on the brominate flux during printed circuit board (PCB) pyrolysis was investigated. It was found that bromine (Br) can be effectively fixed in solid phase during PCB pyrolysis by adding calcium-based waste materials. Phenol and 4-ethylphenol are the major products of pyrolysis. When the two kinds of red mud were used as additive, their content was 85.25 and 84.81%, respectively, which was higher than others. The 2-bromophenol and 2-bromo-4-methyl-benzene are the main Br-containing pyrolysis volatiles. After adding calcium-based additive, these two volatiles were apparently reduced and only small amounts of 2-bromo-4-methyl-benzene were detected in the products, namely 0.71 and 0.86%, respectively for the two kinds of red mud. Hence, no matter from the perspective of product use or simple Br-fixing, the bromine in the three-phase products can be effectively regulated and controlled by adding calcium-based waste residue during PCB pyrolysis. Finally, the Br-fixing mechanism was analysed. As a result, when calcium-based waste materials were added to the PCB pyrolysis it made bromine fix easily in the resident yielding a byproduct that can be further used.

  5. An Evidence-Based Combining Classifier for Brain Signal Analysis

    PubMed Central

    Kheradpisheh, Saeed Reza; Nowzari-Dalini, Abbas; Ebrahimpour, Reza; Ganjtabesh, Mohammad

    2014-01-01

    Nowadays, brain signals are employed in various scientific and practical fields such as Medical Science, Cognitive Science, Neuroscience, and Brain Computer Interfaces. Hence, the need for robust signal analysis methods with adequate accuracy and generalizability is inevitable. The brain signal analysis is faced with complex challenges including small sample size, high dimensionality and noisy signals. Moreover, because of the non-stationarity of brain signals and the impacts of mental states on brain function, the brain signals are associated with an inherent uncertainty. In this paper, an evidence-based combining classifiers method is proposed for brain signal analysis. This method exploits the power of combining classifiers for solving complex problems and the ability of evidence theory to model as well as to reduce the existing uncertainty. The proposed method models the uncertainty in the labels of training samples in each feature space by assigning soft and crisp labels to them. Then, some classifiers are employed to approximate the belief function corresponding to each feature space. By combining the evidence raised from each classifier through the evidence theory, more confident decisions about testing samples can be made. The obtained results by the proposed method compared to some other evidence-based and fixed rule combining methods on artificial and real datasets exhibit the ability of the proposed method in dealing with complex and uncertain classification problems. PMID:24392125

  6. A Combined Experimental/Computational Investigation of a Rocket Based Combined Cycle Inlet

    NASA Technical Reports Server (NTRS)

    Smart, Michael K.; Trexler, Carl A.; Goldman, Allen L.

    2001-01-01

    A rocket based combined cycle inlet geometry has undergone wind tunnel testing and computational analysis with Mach 4 flow at the inlet face. Performance parameters obtained from the wind tunnel tests were the mass capture, the maximum back-pressure, and the self-starting characteristics of the inlet. The CFD analysis supplied a confirmation of the mass capture, the inlet efficiency and the details of the flowfield structure. Physical parameters varied during the test program were cowl geometry, cowl position, body-side bleed magnitude and ingested boundary layer thickness. An optimum configuration was determined for the inlet as a result of this work.

  7. Automated Design of Quantum Circuits

    NASA Technical Reports Server (NTRS)

    Williams, Colin P.; Gray, Alexander G.

    2000-01-01

    In order to design a quantum circuit that performs a desired quantum computation, it is necessary to find a decomposition of the unitary matrix that represents that computation in terms of a sequence of quantum gate operations. To date, such designs have either been found by hand or by exhaustive enumeration of all possible circuit topologies. In this paper we propose an automated approach to quantum circuit design using search heuristics based on principles abstracted from evolutionary genetics, i.e. using a genetic programming algorithm adapted specially for this problem. We demonstrate the method on the task of discovering quantum circuit designs for quantum teleportation. We show that to find a given known circuit design (one which was hand-crafted by a human), the method considers roughly an order of magnitude fewer designs than naive enumeration. In addition, the method finds novel circuit designs superior to those previously known.

  8. Integrated Turbine-Based Combined Cycle Dynamic Simulation Model

    NASA Technical Reports Server (NTRS)

    Haid, Daniel A.; Gamble, Eric J.

    2011-01-01

    A Turbine-Based Combined Cycle (TBCC) dynamic simulation model has been developed to demonstrate all modes of operation, including mode transition, for a turbine-based combined cycle propulsion system. The High Mach Transient Engine Cycle Code (HiTECC) is a highly integrated tool comprised of modules for modeling each of the TBCC systems whose interactions and controllability affect the TBCC propulsion system thrust and operability during its modes of operation. By structuring the simulation modeling tools around the major TBCC functional modes of operation (Dry Turbojet, Afterburning Turbojet, Transition, and Dual Mode Scramjet) the TBCC mode transition and all necessary intermediate events over its entire mission may be developed, modeled, and validated. The reported work details the use of the completed model to simulate a TBCC propulsion system as it accelerates from Mach 2.5, through mode transition, to Mach 7. The completion of this model and its subsequent use to simulate TBCC mode transition significantly extends the state-of-the-art for all TBCC modes of operation by providing a numerical simulation of the systems, interactions, and transient responses affecting the ability of the propulsion system to transition from turbine-based to ramjet/scramjet-based propulsion while maintaining constant thrust.

  9. PIG Ion Source with Permanent Magnets: Model Based Anode Current Return Circuit

    NASA Astrophysics Data System (ADS)

    Babapour Ghadikolaee, Mohammad Reza

    2012-12-01

    Ion sources are widely used in fusion technologies. A new high voltage pulsed power supply for use in penning ion gauge ion sources is proposed in this paper. To use discharge current, a diode-capacitor bank is included. The power supply is composed of 3 stages. A fast switching transistor is used as a single switch which is trigged by a pulse generator. A transformer is used to level up the voltage up to 2 kV without power loss. It is also used to isolate input and high voltage output. Also; the proposed high voltage power supply implementation uses a diode-capacitor bank whose capacitors are charged during plasma discharge. This system structure gives compactness and easiness to implement the total system which in combination with inexpensive commercially available components, makes the unit versatile and inexpensive.

  10. VLSI circuits implementing computational models of neocortical circuits.

    PubMed

    Wijekoon, Jayawan H B; Dudek, Piotr

    2012-09-15

    This paper overviews the design and implementation of three neuromorphic integrated circuits developed for the COLAMN ("Novel Computing Architecture for Cognitive Systems based on the Laminar Microcircuitry of the Neocortex") project. The circuits are implemented in a standard 0.35 μm CMOS technology and include spiking and bursting neuron models, and synapses with short-term (facilitating/depressing) and long-term (STDP and dopamine-modulated STDP) dynamics. They enable execution of complex nonlinear models in accelerated-time, as compared with biology, and with low power consumption. The neural dynamics are implemented using analogue circuit techniques, with digital asynchronous event-based input and output. The circuits provide configurable hardware blocks that can be used to simulate a variety of neural networks. The paper presents experimental results obtained from the fabricated devices, and discusses the advantages and disadvantages of the analogue circuit approach to computational neural modelling. PMID:22342970

  11. Nanoelectronic circuit design and test

    NASA Astrophysics Data System (ADS)

    Simsir, Muzaffer Orkun

    Controlling power consumption in CMOS integrated circuits (ICs) during normal mode of operation is becoming one of the limiting factors to further scaling. In addition, it is a well known fact that during testing of a complex IC, power consumption can far exceed the values reached during its normal operation. High power consumption, combined with limited cooling support, leads to overheating of ICs. This can cause permanent damage to the chip or can invalidate test results due to the fact that extreme temperature variations lead to changes in path delays. Therefore, even good chips can fail the test. For these reasons, thermal problems during test need to be identified to prevent the loss of yield in CMOS ICs. In this thesis, we propose a methodology for thermally characterizing circuits under test. Using this methodology, it is possible to simulate the thermal profiles of the chips during test and prevent possible yield loss because of thermal problems. In addition to the problems associated with power and temperature, a more important barrier is the scaling limitations of the CMOS technology. It has been predicted that in next decade, it will not be possible to scale it further. In the near future, rather than a transition to a completely new technology, extensions to CMOS seem to be more realistic. Double-gate CMOS technology is one of the most promising alternatives that offers a simple extension to CMOS. The transistors of this technology are formed by adding a second gate across the conventional CMOS transistor gate. Designing circuits using this technology has attracted a lot of attention. However, as circuit design methods mature, there is a need to identify how these circuits can be tested. From a circuit testing viewpoint, it is unclear if CMOS fault models are comprehensive enough to model all defects in double-gate CMOS circuits. Therefore, fault models of this technology need to be defined to enable manufacturing-time testing. In this thesis, we

  12. The colour preference control based on two-colour combinations

    NASA Astrophysics Data System (ADS)

    Hong, Ji Young; Kwak, Youngshin; Park, Du-Sik; Kim, Chang Yeong

    2008-02-01

    This paper proposes a framework of colour preference control to satisfy the consumer's colour related emotion. A colour harmony algorithm based on two-colour combinations is developed for displaying the images with several complementary colour pairs as the relationship of two-colour combination. The colours of pixels belonging to complementary colour areas in HSV colour space are shifted toward the target hue colours and there is no colour change for the other pixels. According to the developed technique, dynamic emotions by the proposed hue conversion can be improved and the controlled output image shows improved colour emotions in the preference of the human viewer. The psychophysical experiments are conducted to investigate the optimal model parameters to produce the most pleasant image to the users in the respect of colour emotions.

  13. High-flux ionic diodes, ionic transistors and ionic amplifiers based on external ion concentration polarization by an ion exchange membrane: a new scalable ionic circuit platform.

    PubMed

    Sun, Gongchen; Senapati, Satyajyoti; Chang, Hsueh-Chia

    2016-04-01

    A microfluidic ion exchange membrane hybrid chip is fabricated using polymer-based, lithography-free methods to achieve ionic diode, transistor and amplifier functionalities with the same four-terminal design. The high ionic flux (>100 μA) feature of the chip can enable a scalable integrated ionic circuit platform for micro-total-analytical systems.

  14. High-flux ionic diodes, ionic transistors and ionic amplifiers based on external ion concentration polarization by an ion exchange membrane: a new scalable ionic circuit platform.

    PubMed

    Sun, Gongchen; Senapati, Satyajyoti; Chang, Hsueh-Chia

    2016-04-01

    A microfluidic ion exchange membrane hybrid chip is fabricated using polymer-based, lithography-free methods to achieve ionic diode, transistor and amplifier functionalities with the same four-terminal design. The high ionic flux (>100 μA) feature of the chip can enable a scalable integrated ionic circuit platform for micro-total-analytical systems. PMID:26960551

  15. Unsupervised medical image classification by combining case-based classifiers.

    PubMed

    Dinh, Thien Anh; Silander, Tomi; Su, Bolan; Gong, Tianxia; Pang, Boon Chuan; Lim, C C Tchoyoson; Lee, Cheng Kiang; Tan, Chew Lim; Leong, Tze-Yun

    2013-01-01

    We introduce an automated pathology classification system for medical volumetric brain image slices. Existing work often relies on handcrafted features extracted from automatic image segmentation. This is not only a challenging and time-consuming process, but it may also limit the adaptability and robustness of the system. We propose a novel approach to combine sparse Gabor-feature based classifiers in an ensemble classification framework. The unsupervised nature of this non-parametric technique can significantly reduce the time and effort for system calibration. In particular, classification of medical images in this framework does not rely on segmentation, nor semantic-based or annotation-based feature selection. Our experiments show very promising results in classifying computer tomography image slices into pathological classes for traumatic brain injury patients.

  16. Overview of the Turbine Based Combined Cycle Discipline

    NASA Technical Reports Server (NTRS)

    Thomas, Scott R.; Walker, James F.; Pittman, James L.

    2009-01-01

    The NASA Fundamental Aeronautics Hypersonics project is focused on technologies for combined cycle, airbreathing propulsions systems to enable reusable launch systems for access to space. Turbine Based Combined Cycle (TBCC) propulsion systems offer specific impulse (Isp) improvements over rocket-based propulsion systems in the subsonic takeoff and return mission segments and offer improved safety. The potential to realize more aircraft-like operations with expanded launch site capability and reduced system maintenance are additional benefits. The most critical TBCC enabling technologies as identified in the National Aeronautics Institute (NAI) study were: 1) mode transition from the low speed propulsion system to the high speed propulsion system, 2) high Mach turbine engine development, 3) transonic aero-propulsion performance, 4) low-Mach-number dual-mode scramjet operation, 5) innovative 3-D flowpath concepts and 6) innovative turbine based combined cycle integration. To address several of these key TBCC challenges, NASA s Hypersonics project (TBCC Discipline) initiated an experimental mode transition task that includes an analytic research endeavor to assess the state-of-the-art of propulsion system performance and design codes. This initiative includes inlet fluid and turbine performance codes and engineering-level algorithms. This effort has been focused on the Combined Cycle Engine Large-Scale Inlet Mode Transition Experiment (CCE LIMX) which is a fully integrated TBCC propulsion system with flow path sizing consistent with previous NASA and DoD proposed Hypersonic experimental flight test plans. This experiment is being tested in the NASA-GRC 10 x 10 Supersonic Wind Tunnel (SWT) Facility. The goal of this activity is to address key hypersonic combined-cycle-engine issues: (1) dual integrated inlet operability and performance issues unstart constraints, distortion constraints, bleed requirements, controls, and operability margins, (2) mode

  17. LOGIC CIRCUIT

    DOEpatents

    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)

  18. A new membrane electro-deposition based process for tin recovery from waste printed circuit boards.

    PubMed

    Jian-Guang, Yang; Jie, Lei; Si-Yao, Peng; Yuan-Lu, Lv; Wei-Qiang, Shi

    2016-03-01

    The current research investigated a process combining leaching, purification and membrane electrodeposition to recover tin from the metal components of WPCBs. Experimental results showed that with a solid liquid ratio of 1:4, applying 1.1 times of stoichiometric SnCl4 dosage and HCl concentration of 3.5-4.0 mol/L at a temperature of 60-90°C, 99% of tin can be leached from the metal components of WPCBs. The suitable purification conditions were obtained in the temperature range of 30-45°C with the addition of 1.3-1.4 times of the stoichiometric quantity of tin metal and stirring for a period of 1-2h; followed by adding 1.3 times of the stoichiometric quantity of Na2S for sulfide precipitation about 20-30 min at room temperature. The purified solution was subjected to membrane electrowinning for tin electrodeposition. Under the condition of catholyte Sn(2+) 60 g/L, HCl 3 mol/L and NaCl 20 g/L, current density 200 A/m(2) and temperature 35°C, a compact and smooth cathode tin layer can be obtained. The obtained cathode tin purity exceeded 99% and the electric consumption was less than 1200 kW h/t. The resultant SnCl4 solution generated in anode compartment can be reused as leaching agent for leaching tin again. PMID:26595900

  19. A new membrane electro-deposition based process for tin recovery from waste printed circuit boards.

    PubMed

    Jian-Guang, Yang; Jie, Lei; Si-Yao, Peng; Yuan-Lu, Lv; Wei-Qiang, Shi

    2016-03-01

    The current research investigated a process combining leaching, purification and membrane electrodeposition to recover tin from the metal components of WPCBs. Experimental results showed that with a solid liquid ratio of 1:4, applying 1.1 times of stoichiometric SnCl4 dosage and HCl concentration of 3.5-4.0 mol/L at a temperature of 60-90°C, 99% of tin can be leached from the metal components of WPCBs. The suitable purification conditions were obtained in the temperature range of 30-45°C with the addition of 1.3-1.4 times of the stoichiometric quantity of tin metal and stirring for a period of 1-2h; followed by adding 1.3 times of the stoichiometric quantity of Na2S for sulfide precipitation about 20-30 min at room temperature. The purified solution was subjected to membrane electrowinning for tin electrodeposition. Under the condition of catholyte Sn(2+) 60 g/L, HCl 3 mol/L and NaCl 20 g/L, current density 200 A/m(2) and temperature 35°C, a compact and smooth cathode tin layer can be obtained. The obtained cathode tin purity exceeded 99% and the electric consumption was less than 1200 kW h/t. The resultant SnCl4 solution generated in anode compartment can be reused as leaching agent for leaching tin again.

  20. SEMICONDUCTOR INTEGRATED CIRCUITS: Design for an IO block array in a tile-based FPGA

    NASA Astrophysics Data System (ADS)

    Guangxin, Ding; Lingdou, Chen; Zhongli, Liu

    2009-08-01

    A design for an IO block array in a tile-based FPGA is presented. Corresponding with the characteristics of the FPGA, each IO cell is composed of a signal path, local routing pool and configurable input/output buffers. Shared programmable registers in the signal path can be configured for the function of JTAG, without specific boundary scan registers/latches, saving layout area. The local routing pool increases the flexibility of routing and the routability of the whole FPGA. An auxiliary power supply is adopted to increase the performance of the IO buffers at different configured IO standards. The organization of the IO block array is described in an architecture description file, from which the array layout can be accomplished through use of an automated layout assembly tool. This design strategy facilitates the design of FPGAs with different capacities or architectures in an FPGA family series. The bond-out schemes of the same FPGA chip in different packages are also considered. The layout is based on SMIC 0.13 μm logic 1P8M salicide 1.2/2.5 V CMOS technology. Our performance is comparable with commercial SRAM-based FPGAs which use a similar process.

  1. A novel timestamp based adaptive clock method for circuit emulation service over packet network

    NASA Astrophysics Data System (ADS)

    Dai, Jin-you; Yu, Shao-hua

    2007-11-01

    It is necessary to transport TDM (time division multiplexing) over packet network such as IP and Ethernet, and synchronization is a problem when carrying TDM over the packet network. Clock methods for TDM over packet network are introduced. A new adaptive clock method is presented. The method is a kind of timestamp based adaptive method, but no timestamp needs transporting over packet network. By using the local oscillator and a counter, the timestamp information (local timestamp) related to the service clock of the remote PE (provide edge) and the near PE can be attained. By using D-EWMA filter algorithm, the noise caused by packet network can be filtered and the useful timestamp can be extracted out. With the timestamp and a voltage-controlled oscillator, clock frequency of near PE can be adjusted the same as clock frequency of the remote PE. A kind of simulation device is designed and a test network topology is set up to test and verify the method. The experiment result shows that synthetical performance of the new method is better than ordinary buffer based method and ordinary timestamp based method.

  2. 670 GHz Schottky Diode Based Subharmonic Mixer with CPW Circuits and 70 GHz IF

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Goutam (Inventor); Schlecht, Erich T. (Inventor); Lee, Choonsup (Inventor); Lin, Robert H. (Inventor); Gill, John J. (Inventor); Sin, Seth (Inventor); Mehdi, Imran (Inventor)

    2014-01-01

    A coplanar waveguide (CPW) based subharmonic mixer working at 670 GHz using GaAs Schottky diodes. One example of the mixer has a LO input, an RF input and an IF output. Another possible mixer has a LO input, and IF input and an RF output. Each input or output is connected to a coplanar waveguide with a matching network. A pair of antiparallel diodes provides a signal at twice the LO frequency, which is then mixed with a second signal to provide signals having sum and difference frequencies. The output signal of interest is received after passing through a bandpass filter tuned to the frequency range of interest.

  3. The Neural Network Underlying Incentive-Based Learning: Implications for Interpreting Circuit Disruptions in Psychiatric Disorders

    PubMed Central

    Haber, Suzanne N.; Behrens, Timothy E.J.

    2014-01-01

    Coupling stimuli and actions with positive or negative outcomes facilitates the selection of appropriate actions. Several brain regions are involved in the development of goal-directed behaviors and habit formation during incentive-based learning. This Review focuses on higher cognitive control of decision making and the cortical and subcortical structures and connections that attribute value to stimuli, associate that value with choices, and select an action plan. Delineating the connectivity between these areas is fundamental for understanding how brain regions work together to evaluate stimuli, develop actions plans, and modify behavior, as well as for elucidating the pathophysiology of psychiatric diseases. PMID:25189208

  4. A quantum galvanometer with high-energy resolution based on a superconducting interferometer circuit

    SciTech Connect

    Bakhtin, P.A.; Makhov, V.I.; Masalov, V.V.; Sretenskii, V.N.; Tyablikov, A.V.; Vasenkov, A.A.

    1985-07-01

    The authors make a comprehensive analysis of principles of constructing measurement systems based on the superconducting quantum interferometer (SQUID) implemented in integrated form. They note trends of promising applications for galvanometric measurement systems. They describe the two types of SQUID, one-junction and two junction. They analyze the processing and formation of superconducting ion chemical signals and structures. And they present their results in a series of charts and diagrams. They conclude that quantum galvanometry using superconducting microcircuits allows one to propose new experimental studies in microelectronics, the techniques of high-precision measurements, and equipment for metrological work.

  5. Performance of electronic switching circuits based on bipolar power transistors at low temperature

    NASA Astrophysics Data System (ADS)

    El-Ghanam, S. M.; Abdel Basit, W.

    2011-03-01

    In this paper, the performance of the bipolar power transistor of the type MJE13007 was evaluated under very low temperature levels. The investigation was carried out to establish a baseline on functionality and to determine suitability of this device for use in space applications under cryogenic temperatures. The static and dynamic electrical characteristics of the proposed transistor were studied at low temperature levels ranging from room level (300 K) down to 100 K. From which, it is clear that, several electrical parameters were affected due to operation on such very low temperature range, e.g. the threshold voltage ( V γ) increasing from 0.62 up to 1.05 V; while the current gain h FE decreases significantly from 26 down to 0.54. Also, the capacitance-voltage relationships ( C- V) of the collector-base and emitter-base junctions were studied at cryogenic temperatures, where a pronounced decrease was observed in the capacitances value due to temperature decrease. For example, at F = 50 kHz; CCB and CBE decreased from 2.33 nF down to 0.07 nF and from 36.2 down to 12 nF, respectively due to decreasing of temperature level from 300 down to 100 K. Finally the study was extended to include the dynamic characteristics and switching properties of the tested high power transistor. The dependency of both the rise and fall times ( t r, t f) on the temperature shows great variations with temperature.

  6. Multi-format all-optical processing based on a large-scale, hybridly integrated photonic circuit.

    PubMed

    Bougioukos, M; Kouloumentas, Ch; Spyropoulou, M; Giannoulis, G; Kalavrouziotis, D; Maziotis, A; Bakopoulos, P; Harmon, R; Rogers, D; Harrison, J; Poustie, A; Maxwell, G; Avramopoulos, H

    2011-06-01

    We investigate through numerical studies and experiments the performance of a large scale, silica-on-silicon photonic integrated circuit for multi-format regeneration and wavelength-conversion. The circuit encompasses a monolithically integrated array of four SOAs inside two parallel Mach-Zehnder structures, four delay interferometers and a large number of silica waveguides and couplers. Exploiting phase-incoherent techniques, the circuit is capable of processing OOK signals at variable bit rates, DPSK signals at 22 or 44 Gb/s and DQPSK signals at 44 Gbaud. Simulation studies reveal the wavelength-conversion potential of the circuit with enhanced regenerative capabilities for OOK and DPSK modulation formats and acceptable quality degradation for DQPSK format. Regeneration of 22 Gb/s OOK signals with amplified spontaneous emission (ASE) noise and DPSK data signals degraded with amplitude, phase and ASE noise is experimentally validated demonstrating a power penalty improvement up to 1.5 dB.

  7. High power incoherent beam combining of fiber lasers based on a 7 × 1 all-fiber signal combiner

    NASA Astrophysics Data System (ADS)

    Zhou, Xuanfeng; Chen, Zilun; Wang, Zefeng; Hou, Jing; Xu, Xiaojun

    2016-05-01

    We report an experiment of incoherent beam combining based on a 7×1 all-fiber signal combiner with output power up to 6.08 kW. Properties of transmission efficiency and beam quality are analyzed by beam propagation method. Based on the calculative results, a 7×1 all-fiber signal combiner is fabricated. The handle power capacity is tested with average transmission efficiency of 98.9% and beam quality of M2≈10.

  8. Triple effect absorption chiller utilizing two refrigeration circuits

    DOEpatents

    DeVault, Robert C.

    1988-01-01

    A triple effect absorption method and apparatus having a high coefficient of performance. Two single effect absorption circuits are combined with heat exchange occurring between a condenser and absorber of a high temperature circuit, and a generator of a low temperature circuit. The evaporators of both the high and low temperature circuits provide cooling to an external heat load.

  9. Design of Reconfigurable Logic Circuits Based on Single-Layer Magnetic-Tunnel-Junction Elements

    NASA Astrophysics Data System (ADS)

    Lee, Seungyeon; Lee, Gamyoung; Lee, Hyunju; Lee, Seungjun; Shin, Hyungsoon

    2008-04-01

    Magnetologic using magnetic tunnel junction (MTJ) elements is one of the most promising logic technologies owing to its ease of integration and non-volatility. A magnetologic structure consisting of a single-layer MTJ and a current driver has been proposed by the same authors, which can provide enhanced functional flexibility and uniformity while requiring fewer fabrication steps. In this study, various merits of magnetologic using single-layer MTJ elements are fully exploited for the design of a reconfigurable logic device. A design of a reconfigurable 3-bit counter using single-layer MTJ is presented, which can be programmed to operate as a gray counter, an up counter, or a down counter. The functional correctness is verified by hspice simulation based on an hspice macromodel of MTJ that we have developed for a magnetologic design.

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

    NASA Astrophysics Data System (ADS)

    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. Identifying and characterizing key nodes among communities based on electrical-circuit networks.

    PubMed

    Zhu, Fenghui; Wang, Wenxu; Di, Zengru; Fan, Ying

    2014-01-01

    Complex networks with community structures are ubiquitous in the real world. Despite many approaches developed for detecting communities, we continue to lack tools for identifying overlapping and bridging nodes that play crucial roles in the interactions and communications among communities in complex networks. Here we develop an algorithm based on the local flow conservation to effectively and efficiently identify and distinguish the two types of nodes. Our method is applicable in both undirected and directed networks without a priori knowledge of the community structure. Our method bypasses the extremely challenging problem of partitioning communities in the presence of overlapping nodes that may belong to multiple communities. Due to the fact that overlapping and bridging nodes are of paramount importance in maintaining the function of many social and biological networks, our tools open new avenues towards understanding and controlling real complex networks with communities accompanied with the key nodes.

  12. A software-based sensor for combined sewer overflows.

    PubMed

    Leonhardt, G; Fach, S; Engelhard, C; Kinzel, H; Rauch, W

    2012-01-01

    A new methodology for online estimation of excess flow from combined sewer overflow (CSO) structures based on simulation models is presented. If sufficient flow and water level data from the sewer system is available, no rainfall data are needed to run the model. An inverse rainfall-runoff model was developed to simulate net rainfall based on flow and water level data. Excess flow at all CSO structures in a catchment can then be simulated with a rainfall-runoff model. The method is applied to a case study and results show that the inverse rainfall-runoff model can be used instead of missing rain gauges. Online operation is ensured by software providing an interface to the SCADA-system of the operator and controlling the model. A water quality model could be included to simulate also pollutant concentrations in the excess flow. PMID:22864433

  13. Neuroarchitecture and neuroanatomy of the Drosophila central complex: A GAL4-based dissection of protocerebral bridge neurons and circuits

    PubMed Central

    Wolff, Tanya; Iyer, Nirmala A; Rubin, Gerald M

    2015-01-01

    Insects exhibit an elaborate repertoire of behaviors in response to environmental stimuli. The central complex plays a key role in combining various modalities of sensory information with an insect's internal state and past experience to select appropriate responses. Progress has been made in understanding the broad spectrum of outputs from the central complex neuropils and circuits involved in numerous behaviors. Many resident neurons have also been identified. However, the specific roles of these intricate structures and the functional connections between them remain largely obscure. Significant gains rely on obtaining a comprehensive catalog of the neurons and associated GAL4 lines that arborize within these brain regions, and on mapping neuronal pathways connecting these structures. To this end, small populations of neurons in the Drosophila melanogaster central complex were stochastically labeled using the multicolor flip-out technique and a catalog was created of the neurons, their morphologies, trajectories, relative arrangements, and corresponding GAL4 lines. This report focuses on one structure of the central complex, the protocerebral bridge, and identifies just 17 morphologically distinct cell types that arborize in this structure. This work also provides new insights into the anatomical structure of the four components of the central complex and its accessory neuropils. Most strikingly, we found that the protocerebral bridge contains 18 glomeruli, not 16, as previously believed. Revised wiring diagrams that take into account this updated architectural design are presented. This updated map of the Drosophila central complex will facilitate a deeper behavioral and physiological dissection of this sophisticated set of structures. J. Comp. Neurol. 523:997–1037, 2015. © 2014 Wiley Periodicals, Inc. PMID:25380328

  14. Integrated circuit-based electrochemical sensor for spatially resolved detection of redox-active metabolites in biofilms.

    PubMed

    Bellin, Daniel L; Sakhtah, Hassan; Rosenstein, Jacob K; Levine, Peter M; Thimot, Jordan; Emmett, Kevin; Dietrich, Lars E P; Shepard, Kenneth L

    2014-01-01

    Despite advances in monitoring spatiotemporal expression patterns of genes and proteins with fluorescent probes, direct detection of metabolites and small molecules remains challenging. A technique for spatially resolved detection of small molecules would benefit the study of redox-active metabolites that are produced by microbial biofilms and can affect their development. Here we present an integrated circuit-based electrochemical sensing platform featuring an array of working electrodes and parallel potentiostat channels. 'Images' over a 3.25 × 0.9 mm(2) area can be captured with a diffusion-limited spatial resolution of 750 μm. We demonstrate that square wave voltammetry can be used to detect, identify and quantify (for concentrations as low as 2.6 μM) four distinct redox-active metabolites called phenazines. We characterize phenazine production in both wild-type and mutant Pseudomonas aeruginosa PA14 colony biofilms, and find correlations with fluorescent reporter imaging of phenazine biosynthetic gene expression.

  15. Integrated circuit-based electrochemical sensor for spatially resolved detection of redox-active metabolites in biofilms

    PubMed Central

    Bellin, Daniel L.; Sakhtah, Hassan; Rosenstein, Jacob K.; Levine, Peter M.; Thimot, Jordan; Emmett, Kevin; Dietrich, Lars E. P.; Shepard, Kenneth L.

    2014-01-01

    Despite advances in monitoring spatiotemporal expression patterns of genes and proteins with fluorescent probes, direct detection of metabolites and small molecules remains challenging. A technique for spatially resolved detection of small molecules would benefit the study of redox-active metabolites produced by microbial biofilms, which can drastically affect colony development. Here we present an integrated circuit-based electrochemical sensing platform featuring an array of working electrodes and parallel potentiostat channels. “Images” over a 3.25 × 0.9 mm area can be captured with a diffusion-limited spatial resolution of 750 μm. We demonstrate that square wave voltammetry can be used to detect, identify, and quantify (for concentrations as low as 2.6 μM) four distinct redox-active metabolites called phenazines. We characterize phenazine production in both wild-type and mutant Pseudomonas aeruginosa PA14 colony biofilms, and find correlations with fluorescent reporter imaging of phenazine biosynthetic gene expression. PMID:24510163

  16. EEG acquisition system based on active electrodes with common-mode interference suppression by Driving Right Leg circuit.

    PubMed

    Guermandi, Marco; Bigucci, Alessandro; Franchi Scarselli, Eleonora; Guerrieri, Roberto

    2015-01-01

    We present a system for the acquisition of EEG signals based on active electrodes and implementing a Driving Right Leg circuit (DgRL). DgRL allows for single-ended amplification and analog-to-digital conversion, still guaranteeing a common mode rejection in excess of 110 dB. This allows the system to acquire high-quality EEG signals essentially removing network interference for both wet and dry-contact electrodes. The front-end amplification stage is integrated on the electrode, minimizing the system's sensitivity to electrode contact quality, cable movement and common mode interference. The A/D conversion stage can be either integrated in the remote back-end or placed on the head as well, allowing for an all-digital communication to the back-end. Noise integrated in the band from 0.5 to 100 Hz is comprised between 0.62 and 1.3 μV, depending on the configuration. Current consumption for the amplification and A/D conversion of one channel is 390 μA. Thanks to its low noise, the high level of interference suppression and its quick setup capabilities, the system is particularly suitable for use outside clinical environments, such as in home care, brain-computer interfaces or consumer-oriented applications.

  17. Integrated circuit-based electrochemical sensor for spatially resolved detection of redox-active metabolites in biofilms

    NASA Astrophysics Data System (ADS)

    Bellin, Daniel L.; Sakhtah, Hassan; Rosenstein, Jacob K.; Levine, Peter M.; Thimot, Jordan; Emmett, Kevin; Dietrich, Lars E. P.; Shepard, Kenneth L.

    2014-02-01

    Despite advances in monitoring spatiotemporal expression patterns of genes and proteins with fluorescent probes, direct detection of metabolites and small molecules remains challenging. A technique for spatially resolved detection of small molecules would benefit the study of redox-active metabolites that are produced by microbial biofilms and can affect their development. Here we present an integrated circuit-based electrochemical sensing platform featuring an array of working electrodes and parallel potentiostat channels. ‘Images’ over a 3.25 × 0.9 mm2 area can be captured with a diffusion-limited spatial resolution of 750 μm. We demonstrate that square wave voltammetry can be used to detect, identify and quantify (for concentrations as low as 2.6 μM) four distinct redox-active metabolites called phenazines. We characterize phenazine production in both wild-type and mutant Pseudomonas aeruginosa PA14 colony biofilms, and find correlations with fluorescent reporter imaging of phenazine biosynthetic gene expression.

  18. Fluorescence detection test by black printed circuit board based microfluidic channel for polymerase chain reaction.

    PubMed

    Hwang, Ji-Soo; Kim, Yu-Seop; Song, Hye-Jeong; Kim, Jong-Dae; Park, Chan-Young

    2015-01-01

    This paper proposes the optimal structure of a PCB-based micro PCR chip constructed on a PCB substrate using commercial adhesive tapes and plastic covers. The solder mask of the PCB substrate was coated black, and the area where the reaction chamber is attached was legend printed with white silk to minimize the noise during fluorescence detection. The performance of the PCR and fluorescence detection was compared using 6 types of reaction chambers, each made with different double-sided tapes. Three of the chambers were unsuccessful in completing the PCR. The performance of the other three chambers that successfully amplified DNA was compared using Taqman probe for Chlamydia Trachomatis DNA. The amplified product was illuminated diagonally with a blue LED to excite the product just before imaging, and the LED was turned off when the image was captured to prevent quenching of the probe. The images were taken 10 seconds prior to the last extension step for each cycle using a DSLR camera. The experiments were run as a quartet for each three chambers made with different double-sided tape. The results showed that there were significant difference between the three tapes. PMID:26409548

  19. Combined Feature Based and Shape Based Visual Tracker for Robot Navigation

    NASA Technical Reports Server (NTRS)

    Deans, J.; Kunz, C.; Sargent, R.; Park, E.; Pedersen, L.

    2005-01-01

    We have developed a combined feature based and shape based visual tracking system designed to enable a planetary rover to visually track and servo to specific points chosen by a user with centimeter precision. The feature based tracker uses invariant feature detection and matching across a stereo pair, as well as matching pairs before and after robot movement in order to compute an incremental 6-DOF motion at each tracker update. This tracking method is subject to drift over time, which can be compensated by the shape based method. The shape based tracking method consists of 3D model registration, which recovers 6-DOF motion given sufficient shape and proper initialization. By integrating complementary algorithms, the combined tracker leverages the efficiency and robustness of feature based methods with the precision and accuracy of model registration. In this paper, we present the algorithms and their integration into a combined visual tracking system.

  20. Ultrashort broadband polarization beam splitter based on a combined hybrid plasmonic waveguide.

    PubMed

    Chang, Ken-Wei; Huang, Chia-Chien

    2016-01-01

    We propose an ultracompact broadband polarization beam splitter (PBS) based on a combined hybrid plasmonic waveguide (HPW). The proposed PBS separates transverse-electric (TE) and transverse-magnetic (TM) modes using a bent lower HPW with vertical nanoscale gaps and a straight upper HPW with a horizontal nanoscale gap, respectively, without relying on an additional coupling region. This design considerably reduces the length of the PBS to the submicron scale (920 nm, the shortest PBS reported to date) while offering polarization extinction ratios (PERs) of ~19 dB (~18 dB) and insertion losses (ILs) of ~0.6 dB (~0.3 dB) for the TE (TM) mode over an extremely broad band of 400 nm (from λ = 1300 nm to 1700 nm, covering entirely second and third telecom windows). The length of the designed PBS can be reduced further to 620 nm while still offering PERs of 15 dB, realizing a densely photonic integrated circuit. Considering the fabrication tolerance, the designed PBS allows for large geometrical deviations of ± 20 nm while restricting PER variations to within 1 dB, except for those in the nanoscale gaps smaller than 10nm. Additionally, we also address the input and ouput coupling efficiencies of the proposed PBS. PMID:26786972

  1. Ultrashort broadband polarization beam splitter based on a combined hybrid plasmonic waveguide

    PubMed Central

    Chang, Ken-Wei; Huang, Chia-Chien

    2016-01-01

    We propose an ultracompact broadband polarization beam splitter (PBS) based on a combined hybrid plasmonic waveguide (HPW). The proposed PBS separates transverse-electric (TE) and transverse-magnetic (TM) modes using a bent lower HPW with vertical nanoscale gaps and a straight upper HPW with a horizontal nanoscale gap, respectively, without relying on an additional coupling region. This design considerably reduces the length of the PBS to the submicron scale (920 nm, the shortest PBS reported to date) while offering polarization extinction ratios (PERs) of ~19 dB (~18 dB) and insertion losses (ILs) of ~0.6 dB (~0.3 dB) for the TE (TM) mode over an extremely broad band of 400 nm (from λ = 1300 nm to 1700 nm, covering entirely second and third telecom windows). The length of the designed PBS can be reduced further to 620 nm while still offering PERs of 15 dB, realizing a densely photonic integrated circuit. Considering the fabrication tolerance, the designed PBS allows for large geometrical deviations of ±20 nm while restricting PER variations to within 1 dB, except for those in the nanoscale gaps smaller than 10nm. Additionally, we also address the input and ouput coupling efficiencies of the proposed PBS. PMID:26786972

  2. Model of turn-on characteristics of InP-based Geiger-mode avalanche photodiodes suitable for circuit simulations

    NASA Astrophysics Data System (ADS)

    Jordy, George; Donnelly, Joseph

    2015-05-01

    A model for the turn-on characteristics of separate-absorber-multiplier InP-based Geiger-mode Avalanche Photodiodes (APDs) has been developed. Verilog-A was used to implement the model in a manner that can be incorporated into circuit simulations. Rather than using SPICE elements to mimic the voltage and current characteristics of the APD, Verilog-A can represent the first order nonlinear differential equations that govern the avalanche current of the APD. This continuous time representation is fundamentally different than the piecewise linear characteristics of other models. The model is based on a driving term for the differential current, which is given by the voltage overbias minus the voltage drop across the device's space-charge resistance RSC. This drop is primarily due to electrons transiting the separate absorber. RSC starts off high and decreases with time as the initial breakdown filament spreads laterally to fill the APD. With constant bias voltage, the initial current grows exponentially until space charge effects reduce the driving function. With increasing current the driving term eventually goes to zero and the APD current saturates. On the other hand, if the APD is biased with a capacitor, the driving term becomes negative as the capacitor discharges, reducing the current and driving the voltage below breakdown. The model parameters depend on device design and are obtained from fitting the model to Monte-Carlo turn-on simulations that include lateral spreading of the carriers of the relevant structure. The Monte-Carlo simulations also provide information on the probability of avalanche, and jitter due to where the photon is absorbed in the APD.

  3. Multi-input and -output logic circuits based on bioelectrocatalysis with horseradish peroxidase and glucose oxidase immobilized in multi-responsive copolymer films on electrodes.

    PubMed

    Yu, Xue; Lian, Wenjing; Zhang, Jiannan; Liu, Hongyun

    2016-06-15

    Herein, poly(N-isopropylacrylamide-co-N,N'-dimethylaminoethylmethacrylate) copolymer films were polymerized on electrode surface with a simple one-step method, and the enzyme horseradish peroxidase (HRP) was embedded in the films simultaneously, which were designated as P(NiPAAm-co-DMEM)-HRP. The films exhibited a reversible structure change with the external stimuli, such as pH, CO2, temperature and SO4(2-), causing the cyclic voltammetric (CV) response of electroactive K3Fe(CN)6 at the film electrodes to display the corresponding multi-stimuli sensitive ON-OFF behavior. Based on the switchable CV property of the system and the electrochemical reduction of H2O2 catalyzed by HRP in the films and mediated by Fe(CN)6(3-) in solution, a 5-input/3-output logic gate was established. To further increase the complexity of the logic system, another enzyme glucose oxidase (GOD) was added into the films, designated as P(NiPAAm-co-DMEM)-HRP-GOD. In the presence of oxygen, the oxidation of glucose in the solution was catalyzed by GOD in the films, and the produced H2O2 in situ was recognized and electrocatalytically reduced by HRP and mediated by Fe(CN)6(3-). Based on the bienzyme films, a cascaded or concatenated 4-input/3-output logic gate system was proposed. The present work combined the multi-responsive interface with bioelectrocatalysis to construct cascaded logic circuits, which might open a new avenue to develop biocomputing elements with more sophisticated functions and design novel glucose biosensors. PMID:26901460

  4. Multi-input and -output logic circuits based on bioelectrocatalysis with horseradish peroxidase and glucose oxidase immobilized in multi-responsive copolymer films on electrodes.

    PubMed

    Yu, Xue; Lian, Wenjing; Zhang, Jiannan; Liu, Hongyun

    2016-06-15

    Herein, poly(N-isopropylacrylamide-co-N,N'-dimethylaminoethylmethacrylate) copolymer films were polymerized on electrode surface with a simple one-step method, and the enzyme horseradish peroxidase (HRP) was embedded in the films simultaneously, which were designated as P(NiPAAm-co-DMEM)-HRP. The films exhibited a reversible structure change with the external stimuli, such as pH, CO2, temperature and SO4(2-), causing the cyclic voltammetric (CV) response of electroactive K3Fe(CN)6 at the film electrodes to display the corresponding multi-stimuli sensitive ON-OFF behavior. Based on the switchable CV property of the system and the electrochemical reduction of H2O2 catalyzed by HRP in the films and mediated by Fe(CN)6(3-) in solution, a 5-input/3-output logic gate was established. To further increase the complexity of the logic system, another enzyme glucose oxidase (GOD) was added into the films, designated as P(NiPAAm-co-DMEM)-HRP-GOD. In the presence of oxygen, the oxidation of glucose in the solution was catalyzed by GOD in the films, and the produced H2O2 in situ was recognized and electrocatalytically reduced by HRP and mediated by Fe(CN)6(3-). Based on the bienzyme films, a cascaded or concatenated 4-input/3-output logic gate system was proposed. The present work combined the multi-responsive interface with bioelectrocatalysis to construct cascaded logic circuits, which might open a new avenue to develop biocomputing elements with more sophisticated functions and design novel glucose biosensors.

  5. A simple tachometer circuit

    NASA Technical Reports Server (NTRS)

    Dimeff, J.

    1972-01-01

    Electric circuit to measure frequency of repetitive sinusoidal or rectangular wave is presented. Components of electric circuit and method of operation are explained. Application of circuit as tachometer for automobile is discussed.

  6. Photomultiplier blanking circuit

    NASA Technical Reports Server (NTRS)

    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.

  7. Memristive Sisyphus circuit for clock signal generation.

    PubMed

    Pershin, Yuriy V; Shevchenko, Sergey N; Nori, Franco

    2016-05-20

    Frequency generators are widely used in electronics. Here, we report the design and experimental realization of a memristive frequency generator employing a unique combination of only digital logic gates, a single-supply voltage and a realistic thresholdtype memristive device. In our circuit, the oscillator frequency and duty cycle are defined by the switching characteristics of the memristive device and external resistors. We demonstrate the circuit operation both experimentally, using a memristor emulator, and theoretically, using a model memristive device with threshold. Importantly, nanoscale realizations of memristive devices offer small-size alternatives to conventional quartz-based oscillators. In addition, the suggested approach can be used for mimicking some cyclic (Sisyphus) processes in nature, such as "dripping ants" or drops from leaky faucets.

  8. Toward Agent Programs with Circuit Semantics

    NASA Technical Reports Server (NTRS)

    Nilsson, Nils J.

    1992-01-01

    New ideas are presented for computing and organizing actions for autonomous agents in dynamic environments-environments in which the agent's current situation cannot always be accurately discerned and in which the effects of actions cannot always be reliably predicted. The notion of 'circuit semantics' for programs based on 'teleo-reactive trees' is introduced. Program execution builds a combinational circuit which receives sensory inputs and controls actions. These formalisms embody a high degree of inherent conditionality and thus yield programs that are suitably reactive to their environments. At the same time, the actions computed by the programs are guided by the overall goals of the agent. The paper also speculates about how programs using these ideas could be automatically generated by artificial intelligence planning systems and adapted by learning methods.

  9. Memristive Sisyphus circuit for clock signal generation

    PubMed Central

    Pershin, Yuriy V.; Shevchenko, Sergey N.; Nori, Franco

    2016-01-01

    Frequency generators are widely used in electronics. Here, we report the design and experimental realization of a memristive frequency generator employing a unique combination of only digital logic gates, a single-supply voltage and a realistic thresholdtype memristive device. In our circuit, the oscillator frequency and duty cycle are defined by the switching characteristics of the memristive device and external resistors. We demonstrate the circuit operation both experimentally, using a memristor emulator, and theoretically, using a model memristive device with threshold. Importantly, nanoscale realizations of memristive devices offer small-size alternatives to conventional quartz-based oscillators. In addition, the suggested approach can be used for mimicking some cyclic (Sisyphus) processes in nature, such as “dripping ants” or drops from leaky faucets. PMID:27199243

  10. Memristive Sisyphus circuit for clock signal generation

    NASA Astrophysics Data System (ADS)

    Pershin, Yuriy V.; Shevchenko, Sergey N.; Nori, Franco

    2016-05-01

    Frequency generators are widely used in electronics. Here, we report the design and experimental realization of a memristive frequency generator employing a unique combination of only digital logic gates, a single-supply voltage and a realistic thresholdtype memristive device. In our circuit, the oscillator frequency and duty cycle are defined by the switching characteristics of the memristive device and external resistors. We demonstrate the circuit operation both experimentally, using a memristor emulator, and theoretically, using a model memristive device with threshold. Importantly, nanoscale realizations of memristive devices offer small-size alternatives to conventional quartz-based oscillators. In addition, the suggested approach can be used for mimicking some cyclic (Sisyphus) processes in nature, such as “dripping ants” or drops from leaky faucets.

  11. Microfabrication of diamond-based slow-wave circuits for mm-wave and THz vacuum electronic sources

    NASA Astrophysics Data System (ADS)

    Lueck, M. R.; Malta, D. M.; Gilchrist, K. H.; Kory, C. L.; Mearini, G. T.; Dayton, J. A.

    2011-06-01

    Planar and helical slow-wave circuits for THz radiation sources have been made using novel microfabrication and assembly methods. A biplanar slow-wave circuit for a 650 GHz backward wave oscillator (BWO) was fabricated through the growth of diamond into high aspect ratio silicon molds and the selective metallization of the tops and sidewalls of 90 µm tall diamond features using lithographically created shadow masks. Helical slow-wave circuits for a 650 GHz BWO and a 95 GHz traveling wave tube were created through the patterning of trenches in thin film diamond, electroplating of gold half-helices, and high accuracy bonding of helix halves. The development of new techniques for the microfabrication of vacuum electronic components will help to facilitate compact and high-power sources for terahertz range radiation.

  12. Auto-programmable impulse neural circuits

    NASA Technical Reports Server (NTRS)

    Watula, D.; Meador, J.

    1990-01-01

    Impulse neural networks use pulse trains to communicate neuron activation levels. Impulse neural circuits emulate natural neurons at a more detailed level than that typically employed by contemporary neural network implementation methods. An impulse neural circuit which realizes short term memory dynamics is presented. The operation of that circuit is then characterized in terms of pulse frequency modulated signals. Both fixed and programmable synapse circuits for realizing long term memory are also described. The implementation of a simple and useful unsupervised learning law is then presented. The implementation of a differential Hebbian learning rule for a specific mean-frequency signal interpretation is shown to have a straightforward implementation using digital combinational logic with a variation of a previously developed programmable synapse circuit. This circuit is expected to be exploited for simple and straightforward implementation of future auto-adaptive neural circuits.

  13. Design of photonic crystal splitters/combiners

    NASA Astrophysics Data System (ADS)

    Kim, Sangin; Park, Ikmo; Lim, Hanjo

    2004-10-01

    Photonic band gap (PBG) structures or photonic crystals have attracted a lot of interest since one of their promising applications is to build compact photonic integrated circuits (PIC). One of key components in PICs is a 1 x 2 optical power splitter or a 2 x 1 combiner. Design of 1 x 2 optical power splitters based on photonic crystal has been investigated by several research groups, but no attention has been paid to the design of 2 x 1 optical combiners. In conventional dielectric waveguide based circuits, optical combiners are obtained just by operating the splitters in the opposite direction and the isolation between two input ports in the combiners is naturally achieved. In photonic crystal based circuits, however, we have found that reciprocal operation of the splitters as combiners will not provide proper isolation between the input ports of the combiners. In this work, microwave-circuit concept has been adopted to obtain isolation between two input ports of the combiner and compact optical power splitters/combiners of good performance have been designed using 2-D photonic crystal. Numerical analysis of the designed splitters/combiners has been performed with the finite-difference time-domain method. The designed splitters/combiners show good isolation between input ports in combiner operation with small return losses.

  14. Characterization and mechanical separation of metals from computer Printed Circuit Boards (PCBs) based on mineral processing methods.

    PubMed

    Sarvar, Mojtaba; Salarirad, Mohammad Mehdi; Shabani, Mohammad Amin

    2015-11-01

    In this paper, a novel mechanical process is proposed for enriching metal content of computer Printed Circuit Boards (PCBs). The PCBs are crushed and divided into three different size fractions namely: -0.59, +0.59 to 1.68 and +1.68 mm. Wet jigging and froth flotation methods are selected for metal enrichment. The coarse size fraction (+1.68 mm) is processed by jigging. The plastic free product is grinded and screened. The oversized product is separated as the first concentrate. It was rich of metal because the grinding process was selective. The undersized product is processed by froth flotation. Based on the obtained results, the middle size fraction (+0.59 to 1.68 mm) and the small size fraction (-0.59 mm) are processed by wet jigging and froth flotation respectively. The wet jigging process is optimized by investigating the effect of pulsation frequency and water flow rate. The results of examining the effect of particle size, solid to liquid ratio, conditioning time and using apolar collector showed that collectorless flotation is a promising method for separating nonmetals of PCBs. 95.6%, 97.5% and 85% of metal content of coarse size, middle size and small size fraction are recovered. The grades of obtained concentrates were 63.3%, 92.5% and 75% respectively. The total recovery is calculated as 95.64% and the grade of the final concentrate was 71.26%. Determining the grade of copper and gold in the final product reveals that 4.95% of copper and 24.46% of gold are lost during the concentration. The major part of the lost gold is accumulated in froth flotation tail.

  15. The effect of class-based task-oriented circuit training on the self-satisfaction of patients with chronic stroke.

    PubMed

    Song, Hyun Seung; Kim, Jin Young; Park, Seong Doo

    2015-01-01

    [Purpose] This study aimed to determine the difference in self-satisfaction in patients by comparing class-based task-oriented circuit training (CTCT) and individual-based task-oriented circuit training (ITCT). [Subjects and Methods] The subjects were 30 patients who had been diagnosed with hemiplegia due to stroke more than six month previously. They were divided into Group I (n=9) for conventional therapy, Group II (n=10) for conventional therapy and ITCT, and Group III (n=11) for conventional therapy and CTCT. In order to determine self-satisfaction as a psychological factor in patients, we used a self-esteem scale (SES), motivation of rehabilitation scale (MR), and relationship change (RCS) scale. [Results] SES, MR, and RCS, which were measured to determine self satisfaction as a psychological factor were significantly different between groups. The Bonferroni post hoc test revealed a significant difference between Group I and Group III in SES, a significant difference between Group I and Group III and Group II and Group III in MR, and a significant difference between Group I and Group III were found. [Conclusion] Based on the above results, task-oriented circuit training was more effective when performed in a class than when performed individually in terms of self-satisfaction. Based on this result, we determined that CTCT has as positive an effect on the mental aspects of stroke patients compared with ITCT.

  16. The effect of class-based task-oriented circuit training on the self-satisfaction of patients with chronic stroke

    PubMed Central

    Song, Hyun Seung; Kim, Jin Young; Park, Seong Doo

    2015-01-01

    [Purpose] This study aimed to determine the difference in self-satisfaction in patients by comparing class-based task-oriented circuit training (CTCT) and individual-based task-oriented circuit training (ITCT). [Subjects and Methods] The subjects were 30 patients who had been diagnosed with hemiplegia due to stroke more than six month previously. They were divided into Group I (n=9) for conventional therapy, Group II (n=10) for conventional therapy and ITCT, and Group III (n=11) for conventional therapy and CTCT. In order to determine self-satisfaction as a psychological factor in patients, we used a self-esteem scale (SES), motivation of rehabilitation scale (MR), and relationship change (RCS) scale. [Results] SES, MR, and RCS, which were measured to determine self satisfaction as a psychological factor were significantly different between groups. The Bonferroni post hoc test revealed a significant difference between Group I and Group III in SES, a significant difference between Group I and Group III and Group II and Group III in MR, and a significant difference between Group I and Group III were found. [Conclusion] Based on the above results, task-oriented circuit training was more effective when performed in a class than when performed individually in terms of self-satisfaction. Based on this result, we determined that CTCT has as positive an effect on the mental aspects of stroke patients compared with ITCT. PMID:25642055

  17. 100 Gb/s photoreceiver module based on 4ch × 25 Gb/s vertical-illumination-type Ge-on-Si photodetectors and amplifier circuits

    NASA Astrophysics Data System (ADS)

    Joo, Jiho; Jang, Ki-Seok; Kim, Sanghoon; Kim, In Gyoo; Oh, Jin Hyuk; Kim, Sun Ae; Kim, Gyungock; Jeong, Gyu-Seob; Chi, Hankyu; Jeong, Deog-Kyoon

    2016-03-01

    We present the performance of 4-channel × 25 Gb/s all-silicon photonic receivers based on hybrid-integrated vertical Ge-on-bulk-silicon photodetectors with 65nm bulk CMOS front-end circuits, characterized over 100 Gb/s. The sensitivity of a single-channel Ge photoreceiver module at a BER = 10-12 was measured -11 dBm at 25 Gb/s, whereas, the measured sensitivity of a 4-ch Ge photoreceiver was -10.06 ~ -10.9 dBm for 25Gb/s operation of each channel, and further improvement is in progress. For comparison, we will also present the performance of a 4-ch × 25 Gb/s photoreceiver module, where commercial InP HBT-based front-end circuits is used, characterized up to 100 Gb/s.

  18. Parametric Study Conducted of Rocket- Based, Combined-Cycle Nozzles

    NASA Technical Reports Server (NTRS)

    Steffen, Christopher J., Jr.; Smith, Timothy D.

    1998-01-01

    Having reached the end of the 20th century, our society is quite familiar with the many benefits of recycling and reusing the products of civilization. The high-technology world of aerospace vehicle design is no exception. Because of the many potential economic benefits of reusable launch vehicles, NASA is aggressively pursuing this technology on several fronts. One of the most promising technologies receiving renewed attention is Rocket-Based, Combined-Cycle (RBCC) propulsion. This propulsion method combines many of the efficiencies of high-performance jet aircraft with the power and high-altitude capability of rocket engines. The goal of the present work at the NASA Lewis Research Center is to further understand the complex fluid physics within RBCC engines that govern system performance. This work is being performed in support of NASA's Advanced Reusable Technologies program. A robust RBCC engine design optimization demands further investigation of the subsystem performance of the engine's complex propulsion cycles. The RBCC propulsion system under consideration at Lewis is defined by four modes of operation in a singlestage- to-orbit configuration. In the first mode, the engine functions as a rocket-driven ejector. When the rocket engine is switched off, subsonic combustion (mode 2) is present in the ramjet mode. As the vehicle continues to accelerate, supersonic combustion (mode 3) occurs in the ramjet mode. Finally, as the edge of the atmosphere is approached and the engine inlet is closed off, the rocket is reignited and the final accent to orbit is undertaken in an all-rocket mode (mode 4). The performance of this fourth and final mode is the subject of this present study. Performance is being monitored in terms of the amount of thrust generated from a given amount of propellant.

  19. LTS junction technology for RSFQ and qubit circuit applications

    NASA Astrophysics Data System (ADS)

    Buchholz, F.-Im.; Balashov, D. V.; Dolata, R.; Hagedorn, D.; Khabipov, M. I.; Kohlmann, J.; Zorin, A. B.; Niemeyer, J.

    2006-10-01

    The potentials of LTS junction technology and electronics offer innovative solutions for the processing of quantum information in RSFQ and qubit circuits. We discuss forthcoming approaches based on standard SIS technology and addressed to the development of new superconducting device concepts. The challenging problem of reducing back action noise of the RSFQ circuits deteriorating coherent properties of the qubit is currently solved by implementing Josephson junctions with non-linear shunts based on LTS SIS-SIN technology. Upgraded NbAlOx trilayer technology enables the fabrication of high-quality mesoscopic Josephson junction transistors down to the nanometer range suitable for a qubit-operation regime. As applications, circuit concepts are presented which combine superconducting devices of different nature.

  20. Analysis based on the diffusion model for saturation silica gel with water vapor at conservation units steam circuit TPP

    NASA Astrophysics Data System (ADS)

    Goldaev, Sergey; Khushvaktov, Alisher

    2015-01-01

    A quantitative analysis of the diffusion model dehumidifying air in the steam circuit of TPP, with a layer of silica gel. Showed that such an approximation, supplemented the experimental value of the coefficient of free diffusion identified by the developed method gives reliable values for the concentration of water vapor absorption over time.

  1. Highly flexible self-powered sensors based on printed circuit board technology for human motion detection and gesture recognition.

    PubMed

    Fuh, Yiin-Kuen; Ho, Hsi-Chun

    2016-03-01

    In this paper, we demonstrate a new integration of printed circuit board (PCB) technology-based self-powered sensors (PSSs) and direct-write, near-field electrospinning (NFES) with polyvinylidene fluoride (PVDF) micro/nano fibers (MNFs) as source materials. Integration with PCB technology is highly desirable for affordable mass production. In addition, we systematically investigate the effects of electrodes with intervals in the range of 0.15 mm to 0.40 mm on the resultant PSS output voltage and current. The results show that at a strain of 0.5% and 5 Hz, a PSS with a gap interval 0.15 mm produces a maximum output voltage of 3 V and a maximum output current of 220 nA. Under the same dimensional constraints, the MNFs are massively connected in series (via accumulation of continuous MNFs across the gaps ) and in parallel (via accumulation of parallel MNFs on the same gap) simultaneously. Finally, encapsulation in a flexible polymer with different interval electrodes demonstrated that electrical superposition can be realized by connecting MNFs collectively and effectively in serial/parallel patterns to achieve a high current and high voltage output, respectively. Further improvement in PSSs based on the effect of cooperativity was experimentally realized by rolling-up the device into a cylindrical shape, resulting in a 130% increase in power output due to the cooperative effect. We assembled the piezoelectric MNF sensors on gloves, bandages and stockings to fabricate devices that can detect different types of human motion, including finger motion and various flexing and extensions of an ankle. The firmly glued PSSs were tested on the glove and ankle respectively to detect and harvest the various movements and the output voltage was recorded as ∼1.5 V under jumping movement (one PSS) and ∼4.5 V for the clenched fist with five fingers bent concurrently (five PSSs). This research shows that piezoelectric MNFs not only have a huge impact on harvesting various external

  2. Highly flexible self-powered sensors based on printed circuit board technology for human motion detection and gesture recognition

    NASA Astrophysics Data System (ADS)

    Fuh, Yiin-Kuen; Ho, Hsi-Chun

    2016-03-01

    In this paper, we demonstrate a new integration of printed circuit board (PCB) technology-based self-powered sensors (PSSs) and direct-write, near-field electrospinning (NFES) with polyvinylidene fluoride (PVDF) micro/nano fibers (MNFs) as source materials. Integration with PCB technology is highly desirable for affordable mass production. In addition, we systematically investigate the effects of electrodes with intervals in the range of 0.15 mm to 0.40 mm on the resultant PSS output voltage and current. The results show that at a strain of 0.5% and 5 Hz, a PSS with a gap interval 0.15 mm produces a maximum output voltage of 3 V and a maximum output current of 220 nA. Under the same dimensional constraints, the MNFs are massively connected in series (via accumulation of continuous MNFs across the gaps ) and in parallel (via accumulation of parallel MNFs on the same gap) simultaneously. Finally, encapsulation in a flexible polymer with different interval electrodes demonstrated that electrical superposition can be realized by connecting MNFs collectively and effectively in serial/parallel patterns to achieve a high current and high voltage output, respectively. Further improvement in PSSs based on the effect of cooperativity was experimentally realized by rolling-up the device into a cylindrical shape, resulting in a 130% increase in power output due to the cooperative effect. We assembled the piezoelectric MNF sensors on gloves, bandages and stockings to fabricate devices that can detect different types of human motion, including finger motion and various flexing and extensions of an ankle. The firmly glued PSSs were tested on the glove and ankle respectively to detect and harvest the various movements and the output voltage was recorded as ∼1.5 V under jumping movement (one PSS) and ∼4.5 V for the clenched fist with five fingers bent concurrently (five PSSs). This research shows that piezoelectric MNFs not only have a huge impact on harvesting various external

  3. Highly flexible self-powered sensors based on printed circuit board technology for human motion detection and gesture recognition.

    PubMed

    Fuh, Yiin-Kuen; Ho, Hsi-Chun

    2016-03-01

    In this paper, we demonstrate a new integration of printed circuit board (PCB) technology-based self-powered sensors (PSSs) and direct-write, near-field electrospinning (NFES) with polyvinylidene fluoride (PVDF) micro/nano fibers (MNFs) as source materials. Integration with PCB technology is highly desirable for affordable mass production. In addition, we systematically investigate the effects of electrodes with intervals in the range of 0.15 mm to 0.40 mm on the resultant PSS output voltage and current. The results show that at a strain of 0.5% and 5 Hz, a PSS with a gap interval 0.15 mm produces a maximum output voltage of 3 V and a maximum output current of 220 nA. Under the same dimensional constraints, the MNFs are massively connected in series (via accumulation of continuous MNFs across the gaps ) and in parallel (via accumulation of parallel MNFs on the same gap) simultaneously. Finally, encapsulation in a flexible polymer with different interval electrodes demonstrated that electrical superposition can be realized by connecting MNFs collectively and effectively in serial/parallel patterns to achieve a high current and high voltage output, respectively. Further improvement in PSSs based on the effect of cooperativity was experimentally realized by rolling-up the device into a cylindrical shape, resulting in a 130% increase in power output due to the cooperative effect. We assembled the piezoelectric MNF sensors on gloves, bandages and stockings to fabricate devices that can detect different types of human motion, including finger motion and various flexing and extensions of an ankle. The firmly glued PSSs were tested on the glove and ankle respectively to detect and harvest the various movements and the output voltage was recorded as ∼1.5 V under jumping movement (one PSS) and ∼4.5 V for the clenched fist with five fingers bent concurrently (five PSSs). This research shows that piezoelectric MNFs not only have a huge impact on harvesting various external

  4. Neuromorphic Silicon Neuron Circuits

    PubMed Central

    Indiveri, Giacomo; Linares-Barranco, Bernabé; Hamilton, Tara Julia; van Schaik, André; Etienne-Cummings, Ralph; Delbruck, Tobi; Liu, Shih-Chii; Dudek, Piotr; Häfliger, Philipp; Renaud, Sylvie; Schemmel, Johannes; Cauwenberghs, Gert; Arthur, John; Hynna, Kai; Folowosele, Fopefolu; Saighi, Sylvain; Serrano-Gotarredona, Teresa; Wijekoon, Jayawan; Wang, Yingxue; Boahen, Kwabena

    2011-01-01

    Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain–machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance-based Hodgkin–Huxley models to bi-dimensional generalized adaptive integrate and fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips. PMID:21747754

  5. Degradation of Artemisinin-Based Combination Therapies Under Tropical Conditions.

    PubMed

    Hall, Zoe; Allan, Elizabeth Louise; van Schalkwyk, Donelly Andrew; van Wyk, Albert; Kaur, Harparkash

    2016-05-01

    Poor quality antimalarials, including falsified, substandard, and degraded drugs, are a serious health concern in malaria-endemic countries. Guidelines are lacking on how to distinguish between substandard and degraded drugs. "Forced degradation" in an oven was carried out on three common artemisinin-based combination therapy (ACT) brands to detect products of degradation using liquid chromatography mass spectrometry and help facilitate classification of degraded drugs. "Natural aging" of 2,880 tablets each of ACTs artemether/lumefantrine and artesunate/amodiaquine was undertaken to evaluate their long-term stability in tropical climates. Samples were aged in the presence and absence of light on-site in Ghana and in a stability chamber (London), removed at regular intervals, and analyzed to determine loss of the active pharmaceutical ingredients (APIs) over time and detect products of degradation. Loss of APIs in naturally aged tablets (both in Ghana and the pharmaceutical stability chamber) was 0-7% over 3 years (∼12 months beyond expiry) with low levels of degradation products detected. Using this developed methodology, it was found that a quarter of ACTs purchased in Enugu, Nigeria (concurrent study), that would have been classified as substandard, were in fact degraded. Presence of degradation products together with evidence of insufficient APIs can be used to classify drugs as degraded.

  6. Rocket-Based Combined Cycle Engine Concept Development

    NASA Technical Reports Server (NTRS)

    Ratekin, G.; Goldman, Allen; Ortwerth, P.; Weisberg, S.; McArthur, J. Craig (Technical Monitor)

    2001-01-01

    The development of rocket-based combined cycle (RBCC) propulsion systems is part of a 12 year effort under both company funding and contract work. The concept is a fixed geometry integrated rocket, ramjet, scramjet, which is hydrogen fueled and uses hydrogen regenerative cooling. The baseline engine structural configuration uses an integral structure that eliminates panel seals, seal purge gas, and closeout side attachments. Engine A5 is the current configuration for NASA Marshall Space Flight Center (MSFC) for the ART program. Engine A5 models the complete flight engine flowpath of inlet, isolator, airbreathing combustor, and nozzle. High-performance rocket thrusters are integrated into the engine enabling both low speed air-augmented rocket (AAR) and high speed pure rocket operation. Engine A5 was tested in GASL's new Flight Acceleration Simulation Test (FAST) facility in all four operating modes, AAR, RAM, SCRAM, and Rocket. Additionally, transition from AAR to RAM and RAM to SCRAM was also demonstrated. Measured performance demonstrated vision vehicle performance levels for Mach 3 AAR operation and ramjet operation from Mach 3 to 4. SCRAM and rocket mode performance was above predictions. For the first time, testing also demonstrated transition between operating modes.

  7. Degradation of Artemisinin-Based Combination Therapies under Tropical Conditions

    PubMed Central

    Hall, Zoe; Allan, Elizabeth Louise; van Schalkwyk, Donelly Andrew; van Wyk, Albert; Kaur, Harparkash

    2016-01-01

    Poor quality antimalarials, including falsified, substandard, and degraded drugs, are a serious health concern in malaria-endemic countries. Guidelines are lacking on how to distinguish between substandard and degraded drugs. “Forced degradation” in an oven was carried out on three common artemisinin-based combination therapy (ACT) brands to detect products of degradation using liquid chromatography mass spectrometry and help facilitate classification of degraded drugs. “Natural aging” of 2,880 tablets each of ACTs artemether/lumefantrine and artesunate/amodiaquine was undertaken to evaluate their long-term stability in tropical climates. Samples were aged in the presence and absence of light on-site in Ghana and in a stability chamber (London), removed at regular intervals, and analyzed to determine loss of the active pharmaceutical ingredients (APIs) over time and detect products of degradation. Loss of APIs in naturally aged tablets (both in Ghana and the pharmaceutical stability chamber) was 0–7% over 3 years (∼12 months beyond expiry) with low levels of degradation products detected. Using this developed methodology, it was found that a quarter of ACTs purchased in Enugu, Nigeria (concurrent study), that would have been classified as substandard, were in fact degraded. Presence of degradation products together with evidence of insufficient APIs can be used to classify drugs as degraded. PMID:26951346

  8. Variational integrators for electric circuits

    SciTech Connect

    Ober-Blöbaum, Sina; Tao, Molei; Cheng, Mulin; Owhadi, Houman; Marsden, Jerrold E.

    2013-06-01

    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.

  9. Topological Properties of Some Integrated Circuits for Very Large Scale Integration Chip Designs

    NASA Astrophysics Data System (ADS)

    Swanson, S.; Lanzerotti, M.; Vernizzi, G.; Kujawski, J.; Weatherwax, A.

    2015-03-01

    This talk presents topological properties of integrated circuits for Very Large Scale Integration chip designs. These circuits can be implemented in very large scale integrated circuits, such as those in high performance microprocessors. Prior work considered basic combinational logic functions and produced a mathematical framework based on algebraic topology for integrated circuits composed of logic gates. Prior work also produced an historically-equivalent interpretation of Mr. E. F. Rent's work for today's complex circuitry in modern high performance microprocessors, where a heuristic linear relationship was observed between the number of connections and number of logic gates. This talk will examine topological properties and connectivity of more complex functionally-equivalent integrated circuits. The views expressed in this article are those of the author and do not reflect the official policy or position of the United States Air Force, Department of Defense or the U.S. Government.

  10. Reconfigurable RF CMOS Circuit for Cognitive Radio

    NASA Astrophysics Data System (ADS)

    Masu, Kazuya; Okada, Kenichi

    Cognitive radio and/or SDR (Software Defined Radio) inherently requires multi-band and multi standard wireless circuit. The circuit is implemented based on Si CMOS technology. In this article, the recent progress of Si RF CMOS is described and the reconfigurable RF CMOS circuit which was proposed by the authors is introduced. At the present and in the future, several kind of Si CMOS technology can be used for RF CMOS circuit implementation. The realistic RF CMOS circuit implementation toward cognitive and/or SDR is discussed.

  11. A quantitative method for determination of carrier escape efficiency in GaN-based light-emitting diodes: A comparison of open- and short-circuit photoluminescence

    SciTech Connect

    Lim, Seung-Hyuk; Ko, Young-Ho; Cho, Yong-Hoon

    2014-03-03

    We propose a method to quantitatively analyze the internal quantum efficiency (IQE) as well as the efficiencies of non-radiative recombination in the active region (NRA) and carrier escape out of the active region (ESC) by comparing open-circuit (OC) to short-circuit (SC) conditions of InGaN-based light-emitting diodes (LEDs). First, the IQE was extracted from excitation-power dependent photoluminescence at low temperature, and the electron-hole wavefunction overlaps were calculated under OC and SC conditions. Then, the NRA and ESC efficiencies were quantitatively deduced and also compared with photocurrent data. The proposed method would be useful for assessing and designing quantum barriers and analyzing leakage current in LEDs.

  12. Micro-power generator supplying source for integrated circuit chip based on Pb(Sn,Zr,Ti)O3 ferroelectric ceramic

    NASA Astrophysics Data System (ADS)

    Zhang, Zhenhai; Cui, Zhanzhong; Yan, Jinglong; Li, Kejie

    2011-04-01

    We have demonstrated both experimentally and theoretically that a tin-modified and niobium-modified lead zirconate titanate (Pb(Sn,Zr,Ti)O3) ferroelectric generator system can function as a micro-power supplying source for integrated circuit (IC) chip of separate nonelectric impulse input shock tube digital delay detonator. The ferroelectric ceramic phase transition under transverse shock wave compression can charge an external storage capacitor. The ferroelectric ceramic micro-pulsed-power system is capable of generating low output voltage pulses with an amplitude of 54.2 V and with transferred energy of 1.73 mJ, ultimately supplying an IC chip with micro-power. This work presents the methodology for theoretical analysis and experimental operation of the ferroelectric generator. Theoretical calculations are conducted based on circuit analysis law and principles of dynamic high pressure and shock wave physics. The experimental results were in good agreement with the theoretical analysis.

  13. Accuracy of prediction of infarct-related arrhythmic circuits from image-based models reconstructed from low and high resolution MRI.

    PubMed

    Deng, Dongdong; Arevalo, Hermenegild; Pashakhanloo, Farhad; Prakosa, Adityo; Ashikaga, Hiroshi; McVeigh, Elliot; Halperin, Henry; Trayanova, Natalia

    2015-01-01

    Identification of optimal ablation sites in hearts with infarct-related ventricular tachycardia (VT) remains difficult to achieve with the current catheter-based mapping techniques. Limitations arise from the ambiguities in determining the reentrant pathways location(s). The goal of this study was to develop experimentally validated, individualized computer models of infarcted swine hearts, reconstructed from high-resolution ex-vivo MRI and to examine the accuracy of the reentrant circuit location prediction when models of the same hearts are instead reconstructed from low clinical-resolution MRI scans. To achieve this goal, we utilized retrospective data obtained from four pigs ~10 weeks post infarction that underwent VT induction via programmed stimulation and epicardial activation mapping via a multielectrode epicardial sock. After the experiment, high-resolution ex-vivo MRI with late gadolinium enhancement was acquired. The Hi-res images were downsampled into two lower resolutions (Med-res and Low-res) in order to replicate image quality obtainable in the clinic. The images were segmented and models were reconstructed from the three image stacks for each pig heart. VT induction similar to what was performed in the experiment was simulated. Results of the reconstructions showed that the geometry of the ventricles including the infarct could be accurately obtained from Med-res and Low-res images. Simulation results demonstrated that induced VTs in the Med-res and Low-res models were located close to those in Hi-res models. Importantly, all models, regardless of image resolution, accurately predicted the VT morphology and circuit location induced in the experiment. These results demonstrate that MRI-based computer models of hearts with ischemic cardiomyopathy could provide a unique opportunity to predict and analyze VT resulting for from specific infarct architecture, and thus may assist in clinical decisions to identify and ablate the reentrant circuit(s). PMID

  14. Understanding the Behaviour of Infinite Ladder Circuits

    ERIC Educational Resources Information Center

    Ucak, C.; Yegin, K.

    2008-01-01

    Infinite ladder circuits are often encountered in undergraduate electrical engineering and physics curricula when dealing with series and parallel combination of impedances, as a part of filter design or wave propagation on transmission lines. The input impedance of such infinite ladder circuits is derived by assuming that the input impedance does…

  15. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made by different manufacturers shall not be combined in the same blasting circuit. (c) Detonator leg wires shall be... used between the blasting cable and detonator circuitry shall— (1) Be undamaged; (2) Be well...

  16. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made by different manufacturers shall not be combined in the same blasting circuit. (c) Detonator leg wires shall be... used between the blasting cable and detonator circuitry shall— (1) Be undamaged; (2) Be well...

  17. Power on reset circuit of 915MHz RFID tags

    NASA Astrophysics Data System (ADS)

    Wang, Zhaomin; Cai, Daolin; Fu, Zhongqian; Chen, Houpeng; Song, Zhitang

    Power on reset circuit provides a reset signal for the entire system into normal working condition. When power reaches normal operating voltage and remains stable, power on reset circuit provides one rectangular pulse signal which has a steep edge for the digital baseband part of the tag. After reset, POR circuit is isolated with the follow-up circuits, having good stability. In this paper, we designed two new static ultra-low power consumption power-on reset circuits. The first circuit uses Schmitt triggers for signal threshold detection and a certain delay. The peak current of the first circuit is 31uA, with a static current being 33 pA. The second circuit is based on a clamp circuit and PMOS gate cross-coupled circuit which greatly reduces the static current (190 pA). And the peak current of the second circuit is 21 μA.

  18. A CMOS integrated timing discriminator circuit for fast scintillation counters

    SciTech Connect

    Jochmann, M.W.

    1998-06-01

    Based on a zero-crossing discriminator using a CR differentiation network for pulse shaping, a new CMOS integrated timing discriminator circuit is proposed for fast (t{sub r} {ge} 2 ns) scintillation counters at the cooler synchrotron COSY-Juelich. By eliminating the input signal`s amplitude information by means of an analog continuous-time divider, a normalized pulse shape at the zero-crossing point is gained over a wide dynamic input amplitude range. In combination with an arming comparator and a monostable multivibrator this yields in a highly precise timing discriminator circuit, that is expected to be useful in different time measurement applications. First measurement results of a CMOS integrated logarithmic amplifier, which is part of the analog continuous-time divider, agree well with the corresponding simulations. Moreover, SPICE simulations of the integrated discriminator circuit promise a time walk well below 200 ps (FWHM) over a 40 dB input amplitude dynamic range.

  19. Using graph theory for automated electric circuit solving

    NASA Astrophysics Data System (ADS)

    Toscano, L.; Stella, S.; Milotti, E.

    2015-05-01

    Graph theory plays many important roles in modern physics and in many different contexts, spanning diverse topics such as the description of scale-free networks and the structure of the universe as a complex directed graph in causal set theory. Graph theory is also ideally suited to describe many concepts in computer science. Therefore it is increasingly important for physics students to master the basic concepts of graph theory. Here we describe a student project where we develop a computational approach to electric circuit solving which is based on graph theoretic concepts. This highly multidisciplinary approach combines abstract mathematics, linear algebra, the physics of circuits, and computer programming to reach the ambitious goal of implementing automated circuit solving.

  20. CIRCUIT2.4. 2-Stage Classification Modeling

    SciTech Connect

    Wilde, R.A.; Anderson, J.V.

    1987-12-01

    CIRCUIT2.4 is used to design optimum two-stage classification configurations and operating conditions for energy conservation. It permits simulation of five basic grinding-classification circuits, including one single-stage and four two-stage classification arrangements. Hydrocyclones, spiral classifiers, and sieve band screens can be simulated, and the user may choose the combination of devices for the flowsheet simulation. In addition, the user may select from four classification modeling methods to achieve the goals of a simulation project using the most familiar concepts. Circuit performance is modeled based on classification parameters or equipment operating conditions. A modular approach was taken in designing the program, which allows future addition of other models with relatively minor changes.

  1. Three-Dimensional Flexible Complementary Metal-Oxide-Semiconductor Logic Circuits Based On Two-Layer Stacks of Single-Walled Carbon Nanotube Networks.

    PubMed

    Zhao, Yudan; Li, Qunqing; Xiao, Xiaoyang; Li, Guanhong; Jin, Yuanhao; Jiang, Kaili; Wang, Jiaping; Fan, Shoushan

    2016-02-23

    We have proposed and fabricated stable and repeatable, flexible, single-walled carbon nanotube (SWCNT) thin film transistor (TFT) complementary metal-oxide-semiconductor (CMOS) integrated circuits based on a three-dimensional (3D) structure. Two layers of SWCNT-TFT devices were stacked, where one layer served as n-type devices and the other one served as p-type devices. On the basis of this method, it is able to save at least half of the area required to construct an inverter and make large-scale and high-density integrated CMOS circuits easier to design and manufacture. The 3D flexible CMOS inverter gain can be as high as 40, and the total noise margin is more than 95%. Moreover, the input and output voltage of the inverter are exactly matched for cascading. 3D flexible CMOS NOR, NAND logic gates, and 15-stage ring oscillators were fabricated on PI substrates with high performance as well. Stable electrical properties of these circuits can be obtained with bending radii as small as 3.16 mm, which shows that such a 3D structure is a reliable architecture and suitable for carbon nanotube electrical applications in complex flexible and wearable electronic devices. PMID:26768020

  2. Flip-flop logic circuit based on fully solution-processed organic thin film transistor devices with reduced variations in electrical performance

    NASA Astrophysics Data System (ADS)

    Takeda, Yasunori; Yoshimura, Yudai; Adib, Faiz Adi Ezarudin Bin; Kumaki, Daisuke; Fukuda, Kenjiro; Tokito, Shizuo

    2015-04-01

    Organic reset-set (RS) flip-flop logic circuits based on pseudo-CMOS inverters have been fabricated using full solution processing at a relatively low process temperatures of 150 °C or less. The work function for printed silver electrodes was increased from 4.7 to 5.4 eV through surface modification with a self-assembled monolayer (SAM) material. A bottom-gate, bottom-contact organic thin-film transistor (OTFT) device using a solution-processable small-molecular semiconductor material exhibited field-effect mobility of 0.40 cm2 V-1 s-1 in the saturation region and a threshold voltage (VTH) of -2.4 V in ambient air operation conditions. In order to reduce the variations in mobility and VTH, we designed a circuit with six transistors arranged in parallel, in order to average out their electrical characteristics. As a result, we have succeeded in reducing these variations without changing the absolute values of the mobility and VTH. The fabricated RS flip-flop circuits were functioned well and exhibited short delay times of 3.5 ms at a supply voltage of 20 V.

  3. Semiconductor Quantum Dot Sensitized Solar Cells Based on Ferricyanide/Ferrocyanide Redox Electrolyte Reaching an Open Circuit Photovoltage of 0.8 V.

    PubMed

    Evangelista, Rosemarie M; Makuta, Satoshi; Yonezu, Shota; Andrews, John; Tachibana, Yasuhiro

    2016-06-01

    Semiconductor quantum dot sensitized solar cells (QDSSCs) have rapidly been developed, and their efficiency has recently exceeded 9%. Their performances have mainly been achieved by focusing on improving short circuit photocurrent employing polysulfide electrolytes. However, the increase of open circuit photovoltage (VOC) cannot be expected with QDSSCs based on the polysulfide electrolytes owing to their relatively negative redox potential (around -0.65 V vs Ag/AgCl). Here, we demonstrate enhancement of the open circuit voltage by employing an alternative electrolyte, ferricyanide/ferrocyanide redox couple. The solar cell performance was optimized by investigating the influence of ferricyanide and ferrocyanide concentration on their interfacial charge transfer and transport kinetics. The optimized ferricyanide/ferrocyanide species concentrations (0.01/0.2 M) result in solar energy conversion efficiency of 2% with VOC of 0.8 V. Since the potential difference between the TiO2 conduction band edge at pH 7 and the electrolyte redox potential is about 0.79 V, although the conduction band edge shifts negatively under the negative bias application into the TiO2 electrode, the solar cell with the optimized electrolyte composition has nearly reached the theoretical maximum voltage. This study suggests a promising method to optimize an electrolyte composition for maximizing solar energy conversion efficiency.

  4. Expert system to design communications circuits

    SciTech Connect

    Tolendino, L.F.; Vahle, M.O.

    1986-07-01

    An expert system has been created to aid the design of fiber optic based communications circuits. The design system is based on an Apollo workstation, LISP and CPSL, an in-house developed expert system language. The optical circuit is taken from design specification through hardware selection and circuit routing to the production of detailed schematics and routing guides. A database containing the entire fiber optic trunk system is also maintained.

  5. Realizing a supercapacitor in an electrical circuit

    NASA Astrophysics Data System (ADS)

    Fukuhara, Mikio; Kuroda, Tomoyuki; Hasegawa, Fumihiko

    2014-11-01

    Capacitors are commonly used in electronic resonance circuits; however, capacitors have not been used for storing large amounts of electrical energy in electrical circuits. Here, we report a superior RC circuit which serves as an electrical storage system characterized by quick charging and long-term discharging of electricity. The improved energy storage characteristics in this mixed electric circuit (R1 + R2C1) with small resistor R1, large resistor R2, and large capacitor C1 are derived from the damming effect by large R2 in simple parallel R2C1 circuit. However, no research work has been carried out previously on the use of capacitors as electrical energy storage devices in circuits. Combined with nanotechnology, we hope that our finding will play a remarkable role in a variety of applications such as hybrid electric vehicles and backup power supplies.

  6. Dual Transformer Model based on Standard Circuit Elements for the Study of Low- and Mid-frequency Transients

    NASA Astrophysics Data System (ADS)

    Jazebi, Saeed

    This thesis is a step forward toward achieving the final objective of creating a fully dual model for transformers including eddy currents and nonlinearities of the iron core using the fundamental electrical components already available in the EMTP-type programs. The model is effective for the study of the performance of transformers during power system transients. This is very important for transformer designers, because the insulation of transformers is determined with the overvoltages caused by lightning or switching operations. There are also internally induced transients that occur when a switch is actuated. For example switching actions for reconfiguration of distribution systems that offers economic advantages, or protective actions to clear faults and large short-circuit currents. Many of the smart grid concepts currently under development by many utilities rely heavily on switching to optimize resources that produce transients in the system. On the other hand, inrush currents produce mechanical forces which deform transformer windings and cause malfunction of the differential protection. Also, transformer performance under ferroresonance and geomagnetic induced currents are necessary to study. In this thesis, a physically consistent dual model applicable to single-phase two-winding transformers is proposed. First, the topology of a dual electrical equivalent circuit is obtained from the direct application of the principle of duality. Then, the model parameters are computed considering the variations of the transformer electromagnetic behavior under various operating conditions. Current modeling techniques use different topological models to represent diverse transient situations. The reversible model proposed in this thesis unifies the terminal and topological equivalent circuits. The model remains invariable for all low-frequency transients including deep saturation conditions driven from any of the two windings. The very high saturation region of the

  7. An ICA-based method for the identification of optimal FMRI features and components using combined group-discriminative techniques

    PubMed Central

    Sui, Jing; Adali, Tülay; Pearlson, Godfrey D.; Calhoun, Vince D.

    2013-01-01

    Extraction of relevant features from multitask functional MRI (fMRI) data in order to identify potential biomarkers for disease, is an attractive goal. In this paper, we introduce a novel feature-based framework, which is sensitive and accurate in detecting group differences (e.g. controls vs. patients) by proposing three key ideas. First, we integrate two goal-directed techniques: coefficient-constrained independent component analysis (CC-ICA) and principal component analysis with reference (PCA-R), both of which improve sensitivity to group differences. Secondly, an automated artifact-removal method is developed for selecting components of interest derived from CC-ICA, with an average accuracy of 91%. Finally, we propose a strategy for optimal feature/component selection, aiming to identify optimal group-discriminative brain networks as well as the tasks within which these circuits are engaged. The group-discriminating performance is evaluated on 15 fMRI feature combinations (5 single features and 10 joint features) collected from 28 healthy control subjects and 25 schizophrenia patients. Results show that a feature from a sensorimotor task and a joint feature from a Sternberg working memory (probe) task and an auditory oddball (target) task are the top two feature combinations distinguishing groups. We identified three optimal features that best separate patients from controls, including brain networks consisting of temporal lobe, default mode and occipital lobe circuits, which when grouped together provide improved capability in classifying group membership. The proposed framework provides a general approach for selecting optimal brain networks which may serve as potential biomarkers of several brain diseases and thus has wide applicability in the neuroimaging research community. PMID:19457398

  8. Circuit breaker lock out assembly

    DOEpatents

    Gordy, Wade T.

    1984-01-01

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

  9. Linearly combined optical structures based on SiON

    NASA Astrophysics Data System (ADS)

    Alagappan, G.; Png, C. E.

    2016-08-01

    We investigate an optical structure that results from a linear combination of two periodic, multilayer dielectric functions of slightly different periodicities. By solving the corresponding Maxwell's equation, we show that such linearly combined optical structure supports a dense number of localized (slow) modes. For a practical implementation of the linear combination of the dielectric functions, we make use a silicon oxynitride (SiON) material platform where the refractive index of SiON can be tuned over a continuous range, by changing the percentage of oxygen. The proposed optical structure works, despite a system of low refractive index contrast, and can be effectively used to create efficient polychromatic slow light systems and devices.

  10. The combinative analysis of spraying target image based on chroma

    NASA Astrophysics Data System (ADS)

    Huang, Jingyao; Zhang, Fajun

    2009-10-01

    Recently, intelligent spray system with vision is a research hotspot due to its application security. This paper propose the design of a novel spraying target extraction system, which is capable of identifying crown of a tree structures that are mainly used in the prevention and treatment of the plant's diseases and insects in the urban tree lawn. But how to differentiate the billboard on the both sides of the streets, especially the green overhead structure billboard, the chroma parameters(three primary colors factor's) of spray-targets, and the character of combination were analyzed by normalization experiment in this paper. In comparative studies, the experiment verified effectively the performance of the chroma combination operation by 2G-R-B processing, and showed this method can effectively strategy that the normalization combination arithmetic preceded the simplification operator for eliminating no spray-target image and divide the crown target effectively from the background.

  11. Additive Manufacturing of Hybrid Circuits

    NASA Astrophysics Data System (ADS)

    Sarobol, Pylin; Cook, Adam; Clem, Paul G.; Keicher, David; Hirschfeld, Deidre; Hall, Aaron C.; Bell, Nelson S.

    2016-07-01

    There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects. Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. Finally, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.

  12. Computing with networks of spiking neurons on a biophysically motivated floating-gate based neuromorphic integrated circuit.

    PubMed

    Brink, S; Nease, S; Hasler, P

    2013-09-01

    Results are presented from several spiking network experiments performed on a novel neuromorphic integrated circuit. The networks are discussed in terms of their computational significance, which includes applications such as arbitrary spatiotemporal pattern generation and recognition, winner-take-all competition, stable generation of rhythmic outputs, and volatile memory. Analogies to the behavior of real biological neural systems are also noted. The alternatives for implementing the same computations are discussed and compared from a computational efficiency standpoint, with the conclusion that implementing neural networks on neuromorphic hardware is significantly more power efficient than numerical integration of model equations on traditional digital hardware.

  13. Bioluminescent bioreporter integrated circuits (BBICs)

    NASA Astrophysics Data System (ADS)

    Simpson, Michael L.; Sayler, Gary S.; Nivens, David; Ripp, Steve; Paulus, Michael J.; Jellison, Gerald E.

    1998-07-01

    As the workhorse of the integrated circuit (IC) industry, the capabilities of CMOS have been expanded well beyond the original applications. The full spectrum of analog circuits from switched-capacitor filters to microwave circuit blocks, and from general-purpose operational amplifiers to sub- nanosecond analog timing circuits for nuclear physics experiments have been implemented in CMOS. This technology has also made in-roads into the growing area of monolithic sensors with devices such as active-pixel sensors and other electro-optical detection devices. While many of the processes used for MEMS fabrication are not compatible with the CMOS IC process, depositing a sensor material onto a previously fabricated CMOS circuit can create a very useful category of sensors. In this work we report a chemical sensor composed of bioluminescent bioreporters (genetically engineered bacteria) deposited onto a micro-luminometer fabricated in a standard CMOS IC process. The bioreporter used for this work emitted 490-nm light when exposed to toluene. This luminescence was detected by the micro- luminometer giving an indication of the concentration of toluene. Other bioluminescent bioreporters sensitive to explosives, mercury, and other organic chemicals and heavy metals have been reported. These could be incorporated (individually or in combination) with the micro-luminometer reported here to form a variety of chemical sensors.

  14. Millimeter-wave and optoelectronic applications of heterostructure integrated circuits

    NASA Technical Reports Server (NTRS)

    Pavlidis, Dimitris

    1991-01-01

    The properties are reviewed of heterostructure devices for microwave-monolithic-integrated circuits (MMICs) and optoelectronic integrated circuits (OICs). Specific devices examined include lattice-matched and pseudomorphic InAlAs/InGaAs high-electron mobility transistors (HEMTs), mixer/multiplier diodes, and heterojunction bipolar transistors (HBTs) developed with a number of materials. MMICs are reviewed that can be employed for amplification, mixing, and signal generation, and receiver/transmitter applications are set forth for OICs based on GaAs and InP heterostructure designs. HEMTs, HBTs, and junction-FETs can be utilized in combination with PIN, MSM, and laser diodes to develop novel communication systems based on technologies that combine microwave and photonic capabilities.

  15. ELECTRONIC INTEGRATING CIRCUIT

    DOEpatents

    Englemann, R.H.

    1963-08-20

    An electronic integrating circuit using a transistor with a capacitor connected between the emitter and collector through which the capacitor discharges at a rate proportional to the input current at the base is described. Means are provided for biasing the base with an operating bias and for applying a voltage pulse to the capacitor for charging to an initial voltage. A current dividing diode is connected between the base and emitter of the transistor, and signal input terminal means are coupled to the juncture of the capacitor and emitter and to the base of the transistor. At the end of the integration period, the residual voltage on said capacitor is less by an amount proportional to the integral of the input signal. Either continuous or intermittent periods of integration are provided. (AEC)

  16. Diurnal variation of the global electric circuit from clustered thunderstorms

    NASA Astrophysics Data System (ADS)

    Hutchins, Michael L.; Holzworth, Robert H.; Brundell, James B.

    2014-01-01

    The diurnal variation of the global electric circuit is investigated using the World Wide Lightning Location Network (WWLLN), which has been shown to identify nearly all thunderstorms (using WWLLN data from 2005). To create an estimate of global electric circuit activity, a clustering algorithm is applied to the WWLLN data set to identify global thunderstorms from 2010 to 2013. Annual, seasonal, and regional thunderstorm activity is investigated in this new WWLLN thunderstorm data set in order to estimate the source behavior of the global electric circuit. Through the clustering algorithm, the total number of active thunderstorms are counted every 30 min creating a measure of the global electric circuit source function. The thunderstorm clusters are compared to precipitation radar data from the Tropical Rainfall Measurement Mission satellite and with case studies of thunderstorm evolution. The clustering algorithm reveals an average of 660±70 thunderstorms active at any given time with a peak-to-peak variation of 36%. The highest number of thunderstorms occurs in November (720±90), and the lowest number occurs in January (610±80). Thunderstorm cluster and electrified storm cloud activity are combined with thunderstorm overflight current measurements to estimate the global electric circuit thunderstorm contribution current to be 1090±70 A with a variation of 24%. By utilizing the global coverage and high time resolution of WWLLN, the total active thunderstorm count and current is shown to be less than previous estimates based on compiled climatologies.

  17. 2 μm wavelength range InP-based type-II quantum well photodiodes heterogeneously integrated on silicon photonic integrated circuits.

    PubMed

    Wang, Ruijun; Sprengel, Stephan; Muneeb, Muhammad; Boehm, Gerhard; Baets, Roel; Amann, Markus-Christian; Roelkens, Gunther

    2015-10-01

    The heterogeneous integration of InP-based type-II quantum well photodiodes on silicon photonic integrated circuits for the 2 µm wavelength range is presented. A responsivity of 1.2 A/W at a wavelength of 2.32 µm and 0.6 A/W at 2.4 µm wavelength is demonstrated. The photodiodes have a dark current of 12 nA at -0.5 V at room temperature. The absorbing active region of the integrated photodiodes consists of six periods of a "W"-shaped quantum well, also allowing for laser integration on the same platform.

  18. Performance of an optical encoder based on a nondiffractive beam implemented with a specific photodetection integrated circuit and a diffractive optical element.

    PubMed

    Quintián, Fernando Perez; Calarco, Nicolás; Lutenberg, Ariel; Lipovetzky, José

    2015-09-01

    In this paper, we study the incremental signal produced by an optical encoder based on a nondiffractive beam (NDB). The NDB is generated by means of a diffractive optical element (DOE). The detection system is composed by an application specific integrated circuit (ASIC) sensor. The sensor consists of an array of eight concentric annular photodiodes, each one provided with a programmable gain amplifier. In this way, the system is able to synthesize a nonuniform detectivity. The contrast, amplitude, and harmonic content of the sinusoidal output signal are analyzed. The influence of the cross talk among the annular photodiodes is placed in evidence through the dependence of the signal contrast on the wavelength.

  19. Clocking and synchronization circuits in multiprocessor systems

    SciTech Connect

    Jeong, D.K.

    1989-01-01

    Microprocessors based on RISC (Reduced Instruction Set Computer) concepts have demonstrated an ability to provide more computing power at a given level of integration than conventional microprocessors. The next step is multiprocessors composed of RISC processing elements. Communication bandwidth among such microprocessors is critical in achieving efficient hardware utilization. This thesis focuses on the communication capability of VLSI circuits and presents new circuit techniques as a guide to build an interconnection network of VLSI microprocessors. Circuit techniques for PLL-based clock generation are described along with stability criteria. The main objective of the circuit is to realize a zero delay buffer. Experimental results show the feasibility of such circuits in VLSI. Synchronizer circuit configurations in both bipolar and MOS technology that best utilize each device, or overcome the technology limit using a bandwidth doubling technique are shown. Interface techniques including handshake mechanisms in such a system are also described.

  20. Contrast-sensitive perceptual grouping and object-based attention in the laminar circuits of primary visual cortex.

    PubMed

    Grossberg, S; Raizada, R D

    2000-01-01

    Recent neurophysiological studies have shown that primary visual cortex, or V1, does more than passively process image features using the feedforward filters suggested by Hubel and Wiesel. It also uses horizontal interactions to group features preattentively into object representations, and feedback interactions to selectively attend to these groupings. All neocortical areas, including V1, are organized into layered circuits. We present a neural model showing how the layered circuits in areas V1 and V2 enable feedforward, horizontal, and feedback interactions to complete perceptual groupings over positions that do not receive contrastive visual inputs, even while attention can only modulate or prime positions that do not receive such inputs. Recent neurophysiological data about how grouping and attention occur and interact in V1 are simulated and explained, and testable predictions are made. These simulations show how attention can selectively propagate along an object grouping and protect it from competitive masking, and how contextual stimuli can enhance or suppress groupings in a contrast-sensitive manner. PMID:10788649

  1. CMOS pulse-width-modulation readout circuit with a wide modulation range for ion-sensitive FET-based sensors

    NASA Astrophysics Data System (ADS)

    Wang, Ruey-Lue; Wu, Wei-De; Yu, Chi; Chiu, Po-Hung; Shi, Jian-Liang; Hao, Yi-Fan; Liao, Hsin-Hao; Tsai, Hann-Huei; Juang, Ying-Zong

    2015-04-01

    A CMOS pulse-width-modulation readout circuit for sensors is presented. An input voltage, Vsen, which comes from a sensor, is converted into a current Isen and then the Isen is used to generate a single pulse by a procedure of constant-time charging and then constant-current discharging. With two signals RESET and SW, a control signal generator produces two signals MS1 and MS2 to control the charging and discharging of the capacitor Cp, and hence the sensitivity of the pulse width can be tuned by changing the period of the SW. The pulse width linearly depends on the Vsen with a linearity of at least 99.996%. The integration of the readout circuit with an ion-sensitive field effect transistor (ISFET) exhibits a measured transfer characteristic of pulse width versus pH value with a sensitivity of -31.6 µs/pH and a linearity of 99.35% after a charging time of 500 µs at 25 °C.

  2. Contrast-sensitive perceptual grouping and object-based attention in the laminar circuits of primary visual cortex.

    PubMed

    Grossberg, S; Raizada, R D

    2000-01-01

    Recent neurophysiological studies have shown that primary visual cortex, or V1, does more than passively process image features using the feedforward filters suggested by Hubel and Wiesel. It also uses horizontal interactions to group features preattentively into object representations, and feedback interactions to selectively attend to these groupings. All neocortical areas, including V1, are organized into layered circuits. We present a neural model showing how the layered circuits in areas V1 and V2 enable feedforward, horizontal, and feedback interactions to complete perceptual groupings over positions that do not receive contrastive visual inputs, even while attention can only modulate or prime positions that do not receive such inputs. Recent neurophysiological data about how grouping and attention occur and interact in V1 are simulated and explained, and testable predictions are made. These simulations show how attention can selectively propagate along an object grouping and protect it from competitive masking, and how contextual stimuli can enhance or suppress groupings in a contrast-sensitive manner.

  3. Experimental study of blast mitigating devices based on combined construction

    NASA Astrophysics Data System (ADS)

    Takayama, K.; Silnikov, M. V.; Chernyshov, M. V.

    2016-09-01

    A robust blast inhibiting bin is the most often used device for damage blast effects suppression. In particular, a top open cylindrical bin significantly reduces a fragmentation effect resulted from a detonation of an explosive device placed inside the bin. However, reduction of blast wave overpressure and impulse by such cylindrical bins is not sufficient [1]. A reasonable alternative to endless increase of height and thickness of robust blast inhibiting bins is a development of destructible inhibitors having no solid elements in their structure and, therefore, excluding secondary fragmentation. So, the family of "Fountain" inhibitors [2,3] localizes and suppresses damaging blast effects due to multiphase working system. The present study is analyzing data obtained in testing of prototypes of new combined inhibitors. Their structure combines robust elements (bottoms, side surfaces) with elements responsible for blast loads reduction due to multi-phase working system (top and low transverse embeddings) and fairings impeding wave propagation in undesirable directions.

  4. Charge regulation circuit

    DOEpatents

    Ball, Don G.

    1992-01-01

    A charge regulation circuit provides regulation of an unregulated voltage supply in the range of 0.01%. The charge regulation circuit is utilized in a preferred embodiment in providing regulated voltage for controlling the operation of a laser.

  5. Electrical Circuits and Water Analogies

    ERIC Educational Resources Information Center

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  6. Reconfigurable electro-optical directed-logic circuit using carrier-depletion micro-ring resonators.

    PubMed

    Qiu, Ciyuan; Gao, Weilu; Soref, Richard; Robinson, Jacob T; Xu, Qianfan

    2014-12-15

    Here we demonstrate a reconfigurable electro-optical directed-logic circuit based on a regular array of integrated optical switches. Each 1×1 optical switch consists of a micro-ring resonator with an embedded lateral p-n junction and a micro-heater. We achieve high-speed on-off switching by applying electrical logic signals to the p-n junction. We can configure the operation mode of each switch by thermal tuning the resonance wavelength. The result is an integrated optical circuit that can be reconfigured to perform any combinational logic operation. As a proof-of-principle, we fabricated a multi-spectral directed-logic circuit based on a fourfold array of switches and showed that this circuit can be reconfigured to perform arbitrary two-input logic functions with speeds up to 3  GB/s.

  7. Synthetic biology: applying biological circuits beyond novel therapies.

    PubMed

    Dobrin, Anton; Saxena, Pratik; Fussenegger, Martin

    2016-04-18

    Synthetic biology, an engineering, circuit-driven approach to biology, has developed whole new classes of therapeutics. Unfortunately, these advances have thus far been undercapitalized upon by basic researchers. As discussed herein, using synthetic circuits, one can undertake exhaustive investigations of the endogenous circuitry found in nature, develop novel detectors and better temporally and spatially controlled inducers. One could detect changes in DNA, RNA, protein or even transient signaling events, in cell-based systems, in live mice, and in humans. Synthetic biology has also developed inducible systems that can be induced chemically, optically or using radio waves. This induction has been re-wired to lead to changes in gene expression, RNA stability and splicing, protein stability and splicing, and signaling via endogenous pathways. Beyond simple detectors and inducible systems, one can combine these modalities and develop novel signal integration circuits that can react to a very precise pre-programmed set of conditions or even to multiple sets of precise conditions. In this review, we highlight some tools that were developed in which these circuits were combined such that the detection of a particular event automatically triggered a specific output. Furthermore, using novel circuit-design strategies, circuits have been developed that can integrate multiple inputs together in Boolean logic gates composed of up to 6 inputs. We highlight the tools available and what has been developed thus far, and highlight how some clinical tools can be very useful in basic science. Most of the systems that are presented can be integrated together; and the possibilities far exceed the number of currently developed strategies.

  8. Synthetic biology: applying biological circuits beyond novel therapies.

    PubMed

    Dobrin, Anton; Saxena, Pratik; Fussenegger, Martin

    2016-04-18

    Synthetic biology, an engineering, circuit-driven approach to biology, has developed whole new classes of therapeutics. Unfortunately, these advances have thus far been undercapitalized upon by basic researchers. As discussed herein, using synthetic circuits, one can undertake exhaustive investigations of the endogenous circuitry found in nature, develop novel detectors and better temporally and spatially controlled inducers. One could detect changes in DNA, RNA, protein or even transient signaling events, in cell-based systems, in live mice, and in humans. Synthetic biology has also developed inducible systems that can be induced chemically, optically or using radio waves. This induction has been re-wired to lead to changes in gene expression, RNA stability and splicing, protein stability and splicing, and signaling via endogenous pathways. Beyond simple detectors and inducible systems, one can combine these modalities and develop novel signal integration circuits that can react to a very precise pre-programmed set of conditions or even to multiple sets of precise conditions. In this review, we highlight some tools that were developed in which these circuits were combined such that the detection of a particular event automatically triggered a specific output. Furthermore, using novel circuit-design strategies, circuits have been developed that can integrate multiple inputs together in Boolean logic gates composed of up to 6 inputs. We highlight the tools available and what has been developed thus far, and highlight how some clinical tools can be very useful in basic science. Most of the systems that are presented can be integrated together; and the possibilities far exceed the number of currently developed strategies. PMID:26705548

  9. Cost optimization in low volume VLSI circuits

    NASA Technical Reports Server (NTRS)

    Cook, K. B., Jr.; Kerns, D. V., Jr.

    1982-01-01

    The relationship of integrated circuit (IC) cost to electronic system cost is developed using models for integrated circuit cost which are based on design/fabrication approach. Emphasis is on understanding the relationship between cost and volume for custom circuits suitable for NASA applications. In this report, reliability is a major consideration in the models developed. Results are given for several typical IC designs using off the shelf, full custom, and semicustom IC's with single and double level metallization.

  10. Piezoelectric drive circuit

    DOEpatents

    Treu, C.A. Jr.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes. 7 figs.

  11. Piezoelectric drive circuit

    DOEpatents

    Treu, Jr., Charles A.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes.

  12. Combining Adaptive Hypermedia with Project and Case-Based Learning

    ERIC Educational Resources Information Center

    Papanikolaou, Kyparisia; Grigoriadou, Maria

    2009-01-01

    In this article we investigate the design of educational hypermedia based on constructivist learning theories. According to the principles of project and case-based learning we present the design rational of an Adaptive Educational Hypermedia system prototype named MyProject; learners working with MyProject undertake a project and the system…

  13. Automatic generation of signal processing integrated circuits

    SciTech Connect

    Pope, S.P.

    1985-01-01

    A system for the automated design of signal processing integrated circuits is described in this thesis. The system is based on a library of circuit cells, and a software package that can configure the cells into complete integrated circuits. The architecture of the cell library is optimized for low and medium bandwidth digital signal processing applications. Circuits designed with the system use a multiprocessor architecture. Input to the system is a design file written in a specialized programming language. Software emulation from the design file is used to verify performance. A two-pass silicon compiler is used to translate the design file into a mask-level description of an integrated circuit. A major goal of the project is to make the system useable by those with little or no formal training in integrated circuits. A second goal is to reduce the time and cost associated with performing an integrated circuit design, while still producing designs which are reasonably efficient in their use of the technology. Development of the system was guided by basic research on appropriate architectures and circuit constructs for signal processors. As part of this research an integrated circuit was designed which performs speech analysis and synthesis. This vocoder circuit is intended for use in low-bit-rate digital speech transmission systems.

  14. New Asteroid Models Based on Combined Dense and Sparse Photometry

    NASA Astrophysics Data System (ADS)

    Hanuš, Josef; Durech, J.

    2010-10-01

    For thousands of asteroids we investigated several ten thousands of sparse photometric data from astrometric projects. These data are available on AstDyS server (Asteroids -- Dynamic Site, http://hamilton.dm.unipi.it). We picked 7 astrometric surveys and used their calibrated photometry in lightcurve inversion method for determination of asteroid's convex shapes and rotational states. We present nearly 100 new asteroid models derived from combined dense and sparse data sets, where sparse photometry is taken from AstDyS server and dense lightcurves are from the Uppsala Asteroid Photometric Catalogue (UAPC) and from several individual observers.

  15. Robust Speaker Authentication Based on Combined Speech and Voiceprint Recognition

    NASA Astrophysics Data System (ADS)

    Malcangi, Mario

    2009-08-01

    Personal authentication is becoming increasingly important in many applications that have to protect proprietary data. Passwords and personal identification numbers (PINs) prove not to be robust enough to ensure that unauthorized people do not use them. Biometric authentication technology may offer a secure, convenient, accurate solution but sometimes fails due to its intrinsically fuzzy nature. This research aims to demonstrate that combining two basic speech processing methods, voiceprint identification and speech recognition, can provide a very high degree of robustness, especially if fuzzy decision logic is used.

  16. A linear circuit analysis program with stiff systems capability

    NASA Technical Reports Server (NTRS)

    Cook, C. H.; Bavuso, S. J.

    1973-01-01

    Several existing network analysis programs have been modified and combined to employ a variable topological approach to circuit translation. Efficient numerical integration techniques are used for transient analysis.

  17. Nanoparticle Based Combination Treatments for Targeting Multiple Hallmarks of Cancer

    PubMed Central

    VanDyke, D; Kyriacopulos, P; Yassini, B; Wright, A; Burkhart, E; Jacek, S; Pratt, M; Peterson, CR; Rai, P

    2016-01-01

    Treatment of cancer remains one of the most challenging tasks facing the healthcare system. Cancer affects the lives of millions of people and is often fatal. Current treatment methods include surgery, chemotherapy, radiation therapies or some combinations of these. However, recurrence is a major problem. These treatments can be invasive with severe side effects. Inefficacies in treatments are a result of the complex and variable biology of cancerous cells. Malignant tumor cells and normal functioning cells share many of the same biological characteristics but the main difference is that in cancer cells there is in an overuse and over expression of these biological characteristics. These pertinent characteristics can be grouped into eight hallmarks, as illustrated by Hanahan and Weinberg. These characteristics include sustaining proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis, activating invasion and metastasis, reprogramming energy metabolism, and evading immune destruction. In order to provide a noninvasive, effective treatment, delivery methods must be explored in order to transport cytotoxic agents used for targeting the hallmarks of cancer in a safer and more effective fashion. The use of nanoparticles as drug delivery carriers provides an effective method in which multiple cytotoxic agents can be safely delivered to cancer tissue to simultaneously target multiple hallmarks. By targeting multiple hallmarks of cancer at once, the efficacy of cancer treatments could be improved drastically. This review explores the uses and efficacy of combination therapies using nanoparticles that can simultaneously target multiple hallmarks of cancer. PMID:27547592

  18. Flexible logic circuits based on top-gate thin film transistors with printed semiconductor carbon nanotubes and top electrodes

    NASA Astrophysics Data System (ADS)

    Xu, Weiwei; Liu, Zhen; Zhao, Jianwen; Xu, Wenya; Gu, Weibing; Zhang, Xiang; Qian, Long; Cui, Zheng

    2014-11-01

    In this report printed thin film transistors and logic circuits on flexible substrates are reported. The top-gate thin film transistors were made of the sorted semiconducting single-walled carbon nanotubes (sc-SWCNTs) ink as channel material and printed silver lines as top electrodes and interconnect. 5 nm HfOx thin films pre-deposited on PET substrates by atomic layer deposition (ALD) act as the adhesion layers to significantly improve the immobilization efficiency of sc-SWCNTs and environmental stability. The immobilization mechanism was investigated in detail. The flexible partially-printed top-gate SWCNT TFTs display ambipolar characteristics with slightly strong p-type when using 50 nm HfOx thin films as dielectric layer, as well as the encapsulation layer by atomic layer deposition (ALD) at 120 °C. The hole mobility, on/off ratio and subthreshold swing (SS) are ~46.2 cm2 V-1 s-1, 105 and 109 mV per decade, respectively. Furthermore, partially-printed TFTs show small hysteresis, low operating voltage (2 V) and high stability in air. Flexible partially-printed inverters show good performance with voltage gain up to 33 with 1.25 V supply voltage, and can work at 10 kHz. The frequency of flexible partially-printed five-stage ring oscillators can reach 1.7 kHz at supply voltages of 2 V with per stage delay times of 58.8 μs. This work paves a way to achieve printed SWCNT advanced logic circuits and systems on flexible substrates.In this report printed thin film transistors and logic circuits on flexible substrates are reported. The top-gate thin film transistors were made of the sorted semiconducting single-walled carbon nanotubes (sc-SWCNTs) ink as channel material and printed silver lines as top electrodes and interconnect. 5 nm HfOx thin films pre-deposited on PET substrates by atomic layer deposition (ALD) act as the adhesion layers to significantly improve the immobilization efficiency of sc-SWCNTs and environmental stability. The immobilization mechanism

  19. Vertical waveguide structure optical printed circuit board based on a low-dielectric and transparent PCB materials

    NASA Astrophysics Data System (ADS)

    Hwang, Sung Hwan; Lee, Woo-Jin; An, Jong Bae; Kim, Gye Won; Kim, Myoung Jin; Jung, Eun Joo; Kim, Young Ho; Jung, Ki Young; Sohn, Ik-Bu; Rho, Byung Sup

    2015-02-01

    This paper suggests an optical printed circuit board (OPCB) having new optical coupling structures, including a laser-drilled and under-filled structure (LD-UFS) and a vertical waveguide structure (VWS). The suggested OPCB has the features of high-speed data transmission as well as highly efficient optical coupling because it was fabricated with low-dielectric and transparent electrical PCB materials through a PCB compatible process. To evaluate and compare the optical and electrical performances of the suggested OPCB with those of other OPCBs, the various types of OPCBs were fabricated and measured. The optical coupling losses of the LD-UFS and the VWS were measured with excellent results of 9.8 and 7.8 dB, respectively, which are lower than that of the basic structure. The electrical 3-dB bandwidth of the OPCB was also evaluated up to more than 40 GHz.

  20. High-performance carbon-nanotube-based complementary field-effect-transistors and integrated circuits with yttrium oxide

    SciTech Connect

    Liang, Shibo; Zhang, Zhiyong Si, Jia; Zhong, Donglai; Peng, Lian-Mao

    2014-08-11

    High-performance p-type carbon nanotube (CNT) transistors utilizing yttrium oxide as gate dielectric are presented by optimizing oxidization and annealing processes. Complementary metal-oxide-semiconductor (CMOS) field-effect-transistors (FETs) are then fabricated on CNTs, and the p- and n-type devices exhibit symmetrical high performances, especially with low threshold voltage near to zero. The corresponding CMOS CNT inverter is demonstrated to operate at an ultra-low supply voltage down to 0.2 V, while displaying sufficient voltage gain, high noise margin, and low power consumption. Yttrium oxide is proven to be a competitive gate dielectric for constructing high-performance CNT CMOS FETs and integrated circuits.

  1. Implementation of 140 Gb/s true random bit generator based on a chaotic photonic integrated circuit.

    PubMed

    Argyris, Apostolos; Deligiannidis, Stavros; Pikasis, Evangelos; Bogris, Adonis; Syvridis, Dimitris

    2010-08-30

    In the present work a photonic integrated circuit (PIC) that emits broadband chaotic signals is employed for ultra-fast generation of true random bit sequences. Chaotic dynamics emerge from a DFB laser, accompanied by a monolithic integrated 1-cm long external cavity (EC) that provides controllable optical feedback. The short length minimizes the existence of external cavity modes, so flattened broadband spectra with minimized intrinsic periodicities can emerge. After sampling and quantization--without including optical de-correlation techniques and using most significant bits (MSB) elimination post-processing--truly random bit streams with bit-rates as high as 140 Gb/s can be generated. Finally, the extreme robustness of the random bit generator for adaptive bit-rate operation and for various operating conditions of the PIC is demonstrated.

  2. Design of millimeter-wave MEMS-based reconfigurable front-end circuits using the standard CMOS technology

    NASA Astrophysics Data System (ADS)

    Chang, Chia-Chan; Hsieh, Sheng-Chi; Chen, Chien-Hsun; Huang, Chin-Yen; Yao, Chun-Han; Lin, Chun-Chi

    2011-12-01

    This paper describes the designs of three reconfigurable CMOS-MEMS front-end components for V-/W-band applications. The suspended MEMS structure is released through post-CMOS micromachining. To achieve circuit reconfigurability, dual-state and multi-state fishbone-beam-drive actuators are proposed herein. The reconfigurable bandstop is fabricated in a 0.35 µm CMOS process with the chip size of 0.765 × 0.98 mm2, showing that the stop-band frequency can be switched from 60 to 50 GHz with 40 V actuation voltage. The measured isolation is better than 38 dB at 60 GHz and 34 dB at 50 GHz, respectively. The bandpass filter-integrated single-pole single-throw switch, using the 0.18 µm CMOS process, demonstrates that insertion loss and return loss are better than 6.2 and 15 dB from 88 to 100 GHz in the on-state, and isolation is better than 21 dB in the off-state with an actuation voltage of 51 V. The chip size is 0.7 × 1.04 mm2. The third component is a reconfigurable slot antenna fabricated in a 0.18 µm CMOS process with the chip size of 1.2 × 1.2 mm2. By utilizing the multi-state actuators, the frequencies of this antenna can be switched to 43, 47, 50.5, 54, 57.5 GHz with return loss better than 20 dB. Those circuits demonstrate good RF performance and are relatively compact by employing several size miniaturizing techniques, thereby enabling a great potential for the future single-chip transceiver.

  3. Analysis of signal processing in vestibular circuits with a novel light-emitting diodes-based fluorescence microscope.

    PubMed

    Direnberger, Stephan; Banchi, Roberto; Brosel, Sonja; Seebacher, Christian; Laimgruber, Stefan; Uhl, Rainer; Felmy, Felix; Straka, Hans; Kunz, Lars

    2015-05-01

    Optical visualization of neural network activity is limited by imaging system-dependent technical tradeoffs. To overcome these constraints, we have developed a powerful low-cost and flexible imaging system with high spectral variability and unique spatio-temporal precision for simultaneous optical recording and manipulation of neural activity of large cell groups. The system comprises eight high-power light-emitting diodes, a camera with a large metal-oxide-semiconductor sensor and a high numerical aperture water-dipping objective. It allows fast and precise control of excitation and simultaneous low noise imaging at high resolution. Adjustable apertures generated two independent areas of variable size and position for simultaneous optical activation and image capture. The experimental applicability of this system was explored in semi-isolated preparations of larval axolotl (Ambystoma mexicanum) with intact inner ear organs and central nervous circuits. Cyclic galvanic stimulation of semicircular canals together with glutamate- and γ-aminobutyric acid (GABA)-uncaging caused a corresponding modulation of Ca(2+) transients in central vestibular neurons. These experiments revealed specific cellular properties as well as synaptic interactions between excitatory and inhibitory inputs, responsible for spatio-temporal-specific sensory signal processing. Location-specific GABA-uncaging revealed a potent inhibitory shunt of vestibular nerve afferent input in the predominating population of tonic vestibular neurons, indicating a considerable impact of local and commissural inhibitory circuits on the processing of head/body motion-related signals. The discovery of these previously unknown properties of vestibular computations demonstrates the merits of our novel microscope system for experimental applications in the field of neurobiology. PMID:25847143

  4. Analysis of signal processing in vestibular circuits with a novel light-emitting diodes-based fluorescence microscope.

    PubMed

    Direnberger, Stephan; Banchi, Roberto; Brosel, Sonja; Seebacher, Christian; Laimgruber, Stefan; Uhl, Rainer; Felmy, Felix; Straka, Hans; Kunz, Lars

    2015-05-01

    Optical visualization of neural network activity is limited by imaging system-dependent technical tradeoffs. To overcome these constraints, we have developed a powerful low-cost and flexible imaging system with high spectral variability and unique spatio-temporal precision for simultaneous optical recording and manipulation of neural activity of large cell groups. The system comprises eight high-power light-emitting diodes, a camera with a large metal-oxide-semiconductor sensor and a high numerical aperture water-dipping objective. It allows fast and precise control of excitation and simultaneous low noise imaging at high resolution. Adjustable apertures generated two independent areas of variable size and position for simultaneous optical activation and image capture. The experimental applicability of this system was explored in semi-isolated preparations of larval axolotl (Ambystoma mexicanum) with intact inner ear organs and central nervous circuits. Cyclic galvanic stimulation of semicircular canals together with glutamate- and γ-aminobutyric acid (GABA)-uncaging caused a corresponding modulation of Ca(2+) transients in central vestibular neurons. These experiments revealed specific cellular properties as well as synaptic interactions between excitatory and inhibitory inputs, responsible for spatio-temporal-specific sensory signal processing. Location-specific GABA-uncaging revealed a potent inhibitory shunt of vestibular nerve afferent input in the predominating population of tonic vestibular neurons, indicating a considerable impact of local and commissural inhibitory circuits on the processing of head/body motion-related signals. The discovery of these previously unknown properties of vestibular computations demonstrates the merits of our novel microscope system for experimental applications in the field of neurobiology.

  5. Combining ground-based and space-based remote sensing to validate climate

    NASA Astrophysics Data System (ADS)

    Yesalusky, Melissa Ann

    The goal of this research was to develop a technique that combined ground-based and space-based remote sensing measurements to obtain the properties necessary to calculate atmospheric flux and their associated heating and cooling rates for validating climate models. This study was conducted and validated using seasonal data from the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site in Lamont Oklahoma. Data were collected over four nonconsecutive months, representing one month for each season, during 2010 and 2011, from the ARM-SGP site and associated collocated satellites. The data collected were used to determine the properties of the atmosphere and clouds for integration into the MODerate resolution atmospheric TRANsmission (MODTRAN) model to assess the upwelling and downwelling atmospheric flux of the atmosphere. The atmospheric flux was calculated using a variety of combinations of ground-based and satellite-based data to determine a combination that reveals the best comparison with the top of the atmosphere and surface flux measurements from the Clouds and the Earth's Radiant Energy System (CERES) satellite and ARMS's Solar Infrared Radiation Stations (SIRS), respectively. After validating the flux and determining the ideal data combinations, the atmospheric heating and cooling profiles were calculated and compared with three current reanalysis model results to determine the feasibility of using this new technique for climate model validation. This comparison revealed good agreement with the models. In general, the differences were less than 0.5 K Day-1 for both the clear and cloudy sky conditions. The month of July was the exception for the longwave spectral region; however, the sources of uncertainty during this month are high, with a high frequency of multilevel cloud cases that are either not detected or not represented correctly in the datasets. The use of satellite cloud climatological data based on the

  6. Visual motion imagery neurofeedback based on the hMT+/V5 complex: evidence for a feedback-specific neural circuit involving neocortical and cerebellar regions

    NASA Astrophysics Data System (ADS)

    Banca, Paula; Sousa, Teresa; Catarina Duarte, Isabel; Castelo-Branco, Miguel

    2015-12-01

    Objective. Current approaches in neurofeedback/brain-computer interface research often focus on identifying, on a subject-by-subject basis, the neural regions that are best suited for self-driven modulation. It is known that the hMT+/V5 complex, an early visual cortical region, is recruited during explicit and implicit motion imagery, in addition to real motion perception. This study tests the feasibility of training healthy volunteers to regulate the level of activation in their hMT+/V5 complex using real-time fMRI neurofeedback and visual motion imagery strategies. Approach. We functionally localized the hMT+/V5 complex to further use as a target region for neurofeedback. An uniform strategy based on motion imagery was used to guide subjects to neuromodulate hMT+/V5. Main results. We found that 15/20 participants achieved successful neurofeedback. This modulation led to the recruitment of a specific network as further assessed by psychophysiological interaction analysis. This specific circuit, including hMT+/V5, putative V6 and medial cerebellum was activated for successful neurofeedback runs. The putamen and anterior insula were recruited for both successful and non-successful runs. Significance. Our findings indicate that hMT+/V5 is a region that can be modulated by focused imagery and that a specific cortico-cerebellar circuit is recruited during visual motion imagery leading to successful neurofeedback. These findings contribute to the debate on the relative potential of extrinsic (sensory) versus intrinsic (default-mode) brain regions in the clinical application of neurofeedback paradigms. This novel circuit might be a good target for future neurofeedback approaches that aim, for example, the training of focused attention in disorders such as ADHD.

  7. Recognition of chemical entities: combining dictionary-based and grammar-based approaches

    PubMed Central

    2015-01-01

    Background The past decade has seen an upsurge in the number of publications in chemistry. The ever-swelling volume of available documents makes it increasingly hard to extract relevant new information from such unstructured texts. The BioCreative CHEMDNER challenge invites the development of systems for the automatic recognition of chemicals in text (CEM task) and for ranking the recognized compounds at the document level (CDI task). We investigated an ensemble approach where dictionary-based named entity recognition is used along with grammar-based recognizers to extract compounds from text. We assessed the performance of ten different commercial and publicly available lexical resources using an open source indexing system (Peregrine), in combination with three different chemical compound recognizers and a set of regular expressions to recognize chemical database identifiers. The effect of different stop-word lists, case-sensitivity matching, and use of chunking information was also investigated. We focused on lexical resources that provide chemical structure information. To rank the different compounds found in a text, we used a term confidence score based on the normalized ratio of the term frequencies in chemical and non-chemical journals. Results The use of stop-word lists greatly improved the performance of the dictionary-based recognition, but there was no additional benefit from using chunking information. A combination of ChEBI and HMDB as lexical resources, the LeadMine tool for grammar-based recognition, and the regular expressions, outperformed any of the individual systems. On the test set, the F-scores were 77.8% (recall 71.2%, precision 85.8%) for the CEM task and 77.6% (recall 71.7%, precision 84.6%) for the CDI task. Missed terms were mainly due to tokenization issues, poor recognition of formulas, and term conjunctions. Conclusions We developed an ensemble system that combines dictionary-based and grammar-based approaches for chemical named

  8. Quasi-Linear Circuit

    NASA Technical Reports Server (NTRS)

    Bradley, William; Bird, Ross; Eldred, Dennis; Zook, Jon; Knowles, Gareth

    2013-01-01

    This work involved developing spacequalifiable switch mode DC/DC power supplies that improve performance with fewer components, and result in elimination of digital components and reduction in magnetics. This design is for missions where systems may be operating under extreme conditions, especially at elevated temperature levels from 200 to 300 degC. Prior art for radiation-tolerant DC/DC converters has been accomplished utilizing classical magnetic-based switch mode converter topologies; however, this requires specific shielding and component de-rating to meet the high-reliability specifications. It requires complex measurement and feedback components, and will not enable automatic re-optimization for larger changes in voltage supply or electrical loading condition. The innovation is a switch mode DC/DC power supply that eliminates the need for processors and most magnetics. It can provide a well-regulated voltage supply with a gain of 1:100 step-up to 8:1 step down, tolerating an up to 30% fluctuation of the voltage supply parameters. The circuit incorporates a ceramic core transformer in a manner that enables it to provide a well-regulated voltage output without use of any processor components or magnetic transformers. The circuit adjusts its internal parameters to re-optimize its performance for changes in supply voltage, environmental conditions, or electrical loading at the output

  9. Combining mariculture and seawater-based solar ponds

    SciTech Connect

    Lowrey, P.; Ford, R.; Collando, F.; Morgan, J.; Frusti, E. . Dept. of Mechanical Engineering)

    1990-05-01

    Solar ponds have been thoroughly studied as a means to produce electricity or heat, but there may be comparable potential to use solar ponds to produce optimized environments for the cultivation of some aquaculture crops. For this, conventional brine-based solar ponds could be used. This strategy would probably be most suitable at desert sites where concentrated brine was abundant, pond liners might not be needed, and the crop produced could be shipped to market. Generally, a heat exchanger would be required to transfer heat from the solar pond into the culture ponds. Culture ponds could therefore use either fresh or marine water. In contrast, this paper explores seawater-based solar ponds. These are solar ponds which use seawater in the bottom storage zone and fresh water in the upper convective zone. Because the required temperature elevations for mariculture are only about 10{degrees}C, seawater-based solar ponds are conceivable. Seawater-based ponds should be very inexpensive because, by the shore, salt costs would be negligible and a liner might be unnecessary.

  10. Neurotrophins and spinal circuit function

    PubMed Central

    Boyce, Vanessa S.; Mendell, Lorne M.

    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 this review we will focus on the effects of neurotrophins, particularly nerve growth factor (NGF), brain derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), on spinal circuits. We also discuss evidence that these molecules can modify functions including nociceptive behavior, motor reflexes and stepping behavior. Since these substances and their receptors are normally present in the spinal cord, they could potentially be useful in improving function in disease states and after injury. Here we review recent findings relevant to these translational issues. PMID:24926235

  11. Cascade photonic integrated circuit architecture for electro-optic in-phase quadrature/single sideband modulation or frequency conversion.

    PubMed

    Hasan, Mehedi; Hall, Trevor

    2015-11-01

    A photonic integrated circuit architecture for implementing frequency upconversion is proposed. The circuit consists of a 1×2 splitter and 2×1 combiner interconnected by two stages of differentially driven phase modulators having 2×2 multimode interference coupler between the stages. A transfer matrix approach is used to model the operation of the architecture. The predictions of the model are validated by simulations performed using an industry standard software tool. The intrinsic conversion efficiency of the proposed design is improved by 6 dB over the alternative functionally equivalent circuit based on dual parallel Mach-Zehnder modulators known in the prior art. A two-tone analysis is presented to study the linearity of the proposed circuit, and a comparison is provided over the alternative. The proposed circuit is suitable for integration in any platform that offers linear electro-optic phase modulation such as LiNbO(3), silicon, III-V, or hybrid technology.

  12. Chua's Circuit: Control and Synchronization

    NASA Astrophysics Data System (ADS)

    Irimiciuc, Stefan-Andrei; Vasilovici, Ovidiu; Dimitriu, Dan-Gheorghe

    Chaos-based data encryption is one of the most reliable methods used in secure communications. This implies a good control of a chaotic system and a good synchronization between the involved systems. Here, experimental results are shown on the control and synchronization of Chua's circuits. The control of the chaotic circuit was achieved by using the switching method. The influence of the control signal characteristics (amplitude, frequency and shape) on the system's states was also investigated. The synchronization of two similar chaotic circuits was studied, emphasizing the importance of the chaotic state characteristics of the Master system in respect to those of Slave system. It was shown that the synchronization does not depend on the chaotic state type, neither on the dimension (x, y or z) used for synchronization.

  13. Quantum interference in plasmonic circuits

    NASA Astrophysics Data System (ADS)

    Heeres, Reinier W.; Kouwenhoven, Leo P.; Zwiller, Valery

    2013-10-01

    Surface plasmon polaritons (plasmons) are a combination of light and a collective oscillation of the free electron plasma at metal/dielectric interfaces. This interaction allows subwavelength confinement of light beyond the diffraction limit inherent to dielectric structures. As a result, the intensity of the electromagnetic field is enhanced, with the possibility to increase the strength of the optical interactions between waveguides, light sources and detectors. Plasmons maintain non-classical photon statistics and preserve entanglement upon transmission through thin, patterned metallic films or weakly confining waveguides. For quantum applications, it is essential that plasmons behave as indistinguishable quantum particles. Here we report on a quantum interference experiment in a nanoscale plasmonic circuit consisting of an on-chip plasmon beamsplitter with integrated superconducting single-photon detectors to allow efficient single plasmon detection. We demonstrate a quantum-mechanical interaction between pairs of indistinguishable surface plasmons by observing Hong-Ou-Mandel (HOM) interference, a hallmark non-classical interference effect that is the basis of linear optics-based quantum computation. Our work shows that it is feasible to shrink quantum optical experiments to the nanoscale and offers a promising route towards subwavelength quantum optical networks.

  14. Electronic switches and control circuits: A compilation

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The innovations in this updated series of compilations dealing with electronic technology represents a carefully selected collection of items on electronic switches and control circuits. Most of the items are based on well-known circuit design concepts that have been simplified or refined to meet NASA's demanding requirement for reliability, simplicity, fail-safe characteristics, and the capability of withstanding environmental extremes.

  15. A Pressure Sensing System for Heart Rate Monitoring with Polymer-Based Pressure Sensors and an Anti-Interference Post Processing Circuit

    PubMed Central

    Shu, Yi; Li, Cheng; Wang, Zhe; Mi, Wentian; Li, Yuxing; Ren, Tian-Ling

    2015-01-01

    Heart rate measurement is a basic and important issue for either medical diagnosis or daily health monitoring. In this work great efforts have been focused on realizing a portable, comfortable and low cost solution for long-term domestic heart rate monitoring. A tiny but efficient measurement system composed of a polymer-based flexible pressure sensor and an analog anti-interference readout circuit is proposed; manufactured and tested. The proposed polymer-based pressure sensor has a linear response and high sensitivity of 13.4 kPa−1. With the circuit’s outstanding capability in removing interference caused by body movement and the highly sensitive flexible sensor device, comfortable long-term heart rate monitoring becomes more realistic. Comparative tests prove that the proposed system has equivalent capability (accuracy: <3%) in heart rate measurement to the commercial product. PMID:25648708

  16. A non-fullerene electron acceptor based on fluorene and diketopyrrolopyrrole building blocks for solution-processable organic solar cells with an impressive open-circuit voltage.

    PubMed

    Patil, Hemlata; Zu, Wang Xi; Gupta, Akhil; Chellappan, Vijila; Bilic, Ante; Sonar, Prashant; Rananaware, Anushri; Bhosale, Sidhanath V; Bhosale, Sheshanath V

    2014-11-21

    A novel solution-processable non-fullerene electron acceptor 6,6'-(5,5'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(thiophene-5,2-diyl))bis(2,5-bis(2-ethylhexyl)-3-(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione) (DPP1) based on fluorene and diketopyrrolopyrrole conjugated moieties was designed, synthesized and fully characterized. DPP1 exhibited excellent solubility and high thermal stability which are essential for easy processing. Upon using DPP1 as an acceptor with the classical electron donor poly(3-hexylthiophene), solution processable bulk-heterojunction solar cells afforded a power conversion efficiency of 1.2% with a high open-circuit voltage (1.1 V). As per our knowledge, this value of open circuit voltage is one of the highest values reported so far for a bulk-heterojunction device using DPP1 as a non-fullerene acceptor.

  17. Robust ellipse fitting based on sparse combination of data points.

    PubMed

    Liang, Junli; Zhang, Miaohua; Liu, Ding; Zeng, Xianju; Ojowu, Ode; Zhao, Kexin; Li, Zhan; Liu, Han

    2013-06-01

    Ellipse fitting is widely applied in the fields of computer vision and automatic industry control, in which the procedure of ellipse fitting often follows the preprocessing step of edge detection in the original image. Therefore, the ellipse fitting method also depends on the accuracy of edge detection besides their own performance, especially due to the introduced outliers and edge point errors from edge detection which will cause severe performance degradation. In this paper, we develop a robust ellipse fitting method to alleviate the influence of outliers. The proposed algorithm solves ellipse parameters by linearly combining a subset of ("more accurate") data points (formed from edge points) rather than all data points (which contain possible outliers). In addition, considering that squaring the fitting residuals can magnify the contributions of these extreme data points, our algorithm replaces it with the absolute residuals to reduce this influence. Moreover, the norm of data point errors is bounded, and the worst case performance optimization is formed to be robust against data point errors. The resulting mixed l1-l2 optimization problem is further derived as a second-order cone programming one and solved by the computationally efficient interior-point methods. Note that the fitting approach developed in this paper specifically deals with the overdetermined system, whereas the current sparse representation theory is only applied to underdetermined systems. Therefore, the proposed algorithm can be looked upon as an extended application and development of the sparse representation theory. Some simulated and experimental examples are presented to illustrate the effectiveness of the proposed ellipse fitting approach. PMID:23412616

  18. Robust ellipse fitting based on sparse combination of data points.

    PubMed

    Liang, Junli; Zhang, Miaohua; Liu, Ding; Zeng, Xianju; Ojowu, Ode; Zhao, Kexin; Li, Zhan; Liu, Han

    2013-06-01

    Ellipse fitting is widely applied in the fields of computer vision and automatic industry control, in which the procedure of ellipse fitting often follows the preprocessing step of edge detection in the original image. Therefore, the ellipse fitting method also depends on the accuracy of edge detection besides their own performance, especially due to the introduced outliers and edge point errors from edge detection which will cause severe performance degradation. In this paper, we develop a robust ellipse fitting method to alleviate the influence of outliers. The proposed algorithm solves ellipse parameters by linearly combining a subset of ("more accurate") data points (formed from edge points) rather than all data points (which contain possible outliers). In addition, considering that squaring the fitting residuals can magnify the contributions of these extreme data points, our algorithm replaces it with the absolute residuals to reduce this influence. Moreover, the norm of data point errors is bounded, and the worst case performance optimization is formed to be robust against data point errors. The resulting mixed l1-l2 optimization problem is further derived as a second-order cone programming one and solved by the computationally efficient interior-point methods. Note that the fitting approach developed in this paper specifically deals with the overdetermined system, whereas the current sparse representation theory is only applied to underdetermined systems. Therefore, the proposed algorithm can be looked upon as an extended application and development of the sparse representation theory. Some simulated and experimental examples are presented to illustrate the effectiveness of the proposed ellipse fitting approach.

  19. PMGA and its application in area and power optimization for ternary FPRM circuit

    NASA Astrophysics Data System (ADS)

    Pengjun, Wang; Kangping, Li; Huihong, Zhang

    2016-01-01

    Based on the research of population migration algorithms (PMAs), a population migration genetic algorithm (PMGA) is proposed, combining a PMA with a genetic algorithm. A scheme of area and power optimization for a ternary FPRM circuit is proposed by using the PMGA. Firstly, according to the ternary FPRM logic function expression, area and power estimation models are established. Secondly, the PMGA is used to search for the best area and power polarity. Finally, 10 MCNC Benchmark circuits are used to verify the effectiveness of the proposed method. The results show that the ternary FPRM circuits optimized by the PMGA saved 13.33% area and 20.00% power on average than the corresponding FPRM circuits optimized by a whole annealing genetic algorithm. Project supported by the Natural Science Foundation of Zhejiang Province (No. LY13F040003), the National Natural Science Foundation of China (Nos. 61234002, 61306041), and the K. C. Wong Magna Fund in Ningbo University.

  20. Microprocessors as a Vehicle for Teaching Circuit Analysis.

    ERIC Educational Resources Information Center

    Neu, Emil C.

    1982-01-01

    Based on the premise that most engineering students will own their own microcomputers, discusses the teaching of circuit analysis, possible directions to be taken in hardware analysis, and impact on the mathematics related to circuit analysis. (SK)

  1. Source circuit design considerations

    NASA Technical Reports Server (NTRS)

    Noel, G. T.

    1983-01-01

    The cost of several circuit configurations for large (5MW) array fields were investigated to assess the relative costs of high and low voltage configurations. Three source circuit NOC voltages were evaluated: 400V (ungrounded), 800V (+ or 400V center grounded), and 2000V (+ or - 1000V center grounded). Four source circuit configurations were considered for each of the three NOC voltages. The configurations correspond to source circuit currents of 15, 30, 45, and 60 amperes, respectively. Conceptual layouts for 5MW building blocks for each of the above configurations were developed. The designs were optimized to minimize BOS electrical and structural costs. Only the BOS electrical costs were evaluated. The designs were broken down into the following elements for cost: (1) basic source circuit intermodule wiring, bypass diodes and associated hardware, source circuit to J-Box wiring, etc; (2) J-Box blocking diodes, varistors, heat sinks, and housing; (3) disconnects source circuit disconnects, fuses, and housing; (4) bus cabling J-Box to PCU interface wiring, and trenching; (5) interface bus bar, group disconnects, and fuses; and (6) fault detection shunts, signal wire, electronics, and alarm. It is concluded that high voltage low current circuits are not economical, at higher currents high and low voltage circuit costs approach each other, high voltage circuits are not likely to offer near term advantage, and development work/manufacturer stimulation is needed to develop low cost high voltage hardware.

  2. Combining region-based and imprecise boundary-based cues for interactive medical image segmentation.

    PubMed

    Jones, Jonathan-Lee; Xie, Xianghua; Essa, Ehab

    2014-12-01

    In this paper, we present an approach combining both region selection and user point selection for user-assisted segmentation as either an enclosed object or an open curve, investigate the method of image segmentation in specific medical applications (user-assisted segmentation of the media-adventitia border in intravascular ultrasound images, and lumen border in optical coherence tomography images), and then demonstrate the method with generic images to show how it could be utilized in other types of medical image and is not limited to the applications described. The proposed method combines point-based soft constraint on object boundary and stroke-based regional constraint. The user points act as attraction points and are treated as soft constraints rather than hard constraints that the segmented boundary has to pass through. The user can also use strokes to specify region of interest. The probabilities of region of interest for each pixel are then calculated, and their discontinuity is used to indicate object boundary. The combinations of different types of user constraints and image features allow flexible and robust segmentation, which is formulated as an energy minimization problem on a multilayered graph and is solved using a shortest path search algorithm. We show that this combinatorial approach allows efficient and effective interactive segmentation, which can be used with both open and closed curves to segment a variety of images in different ways. The proposed method is demonstrated in the two medical applications, that is, intravascular ultrasound and optical coherence tomography images, where image artefacts such as acoustic shadow and calcification are commonplace and thus user guidance is desirable. We carried out both qualitative and quantitative analysis of the results for the medical data; comparing the proposed method against a number of interactive segmentation techniques. PMID:25377853

  3. Fish tracking by combining motion based segmentation and particle filtering

    NASA Astrophysics Data System (ADS)

    Bichot, E.; Mascarilla, L.; Courtellemont, P.

    2006-01-01

    In this paper, we suggest a new importance sampling scheme to improve a particle filtering based tracking process. This scheme relies on exploitation of motion segmentation. More precisely, we propagate hypotheses from particle filtering to blobs of similar motion to target. Hence, search is driven toward regions of interest in the state space and prediction is more accurate. We also propose to exploit segmentation to update target model. Once the moving target has been identified, a representative model is learnt from its spatial support. We refer to this model in the correction step of the tracking process. The importance sampling scheme and the strategy to update target model improve the performance of particle filtering in complex situations of occlusions compared to a simple Bootstrap approach as shown by our experiments on real fish tank sequences.

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

    ERIC Educational Resources Information Center

    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…

  5. Modeling cortical circuits.

    SciTech Connect

    Rohrer, Brandon Robinson; Rothganger, Fredrick H.; Verzi, Stephen J.; Xavier, Patrick Gordon

    2010-09-01

    The neocortex is perhaps the highest region of the human brain, where audio and visual perception takes place along with many important cognitive functions. An important research goal is to describe the mechanisms implemented by the neocortex. There is an apparent regularity in the structure of the neocortex [Brodmann 1909, Mountcastle 1957] which may help simplify this task. The work reported here addresses the problem of how to describe the putative repeated units ('cortical circuits') in a manner that is easily understood and manipulated, with the long-term goal of developing a mathematical and algorithmic description of their function. The approach is to reduce each algorithm to an enhanced perceptron-like structure and describe its computation using difference equations. We organize this algorithmic processing into larger structures based on physiological observations, and implement key modeling concepts in software which runs on parallel computing hardware.

  6. Flexible composite film for printed circuit board

    NASA Technical Reports Server (NTRS)

    Yabe, K.; Asakura, M.; Tanaka, H.; Soda, A.

    1982-01-01

    A flexible printed circuit for a printed circuit board in which layers of reaction product composed of a combination of phenoxy resin - polyisocyanate - brominated epoxy resin, and in which the equivalent ratio of those functional groups is hydroxyl group: isocyanate group: epoxy group - 1 : 0.2 to 2 : 0.5 to 3 are laminated on at least one side of saturated polyester film is discussed.

  7. Dynamical Systems in Circuit Designer's Eyes

    SciTech Connect

    Odyniec, M.

    2011-05-09

    Examples of nonlinear circuit design are given. Focus of the design process is on theory and engineering methods (as opposed to numerical analysis). Modeling is related to measurements It is seen that the phase plane is still very useful with proper models Harmonic balance/describing function offers powerful insight (via the combination of simulation with circuit and ODE theory). Measurement and simulation capabilities increased, especially harmonics measurements (since sinusoids are easy to generate)

  8. Regenerative feedback resonant circuit

    DOEpatents

    Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

    2014-09-02

    A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

  9. Fast Overcurrent Tripping Circuit

    NASA Technical Reports Server (NTRS)

    Sullender, Craig C.; Davies, Bryan L.; Osborn, Stephen H.

    1993-01-01

    Fast overcurrent tripping circuit designed for incorporation into power metal oxide/semiconductor field-effect transistor (MOSFET) switching circuit. Serves as fast electronic circuit breaker by sensing voltage across MOSFET's during conduction and switching MOSFET's off within 1 microsecond after voltage exceeds reference value corresponding to tripping current. Acts more quickly than Hall-effect current sensor and, in comparison with shunt current-measuring circuits, smaller and consumes less power. Also ignores initial transient overcurrents during first 5 microseconds of switching cycle.

  10. Printed circuit board industry.

    PubMed

    LaDou, Joseph

    2006-05-01

    The printed circuit board is the platform upon which microelectronic components such as semiconductor chips and capacitors are mounted. It provides the electrical interconnections between components and is found in virtually all electronics products. Once considered low technology, the printed circuit board is evolving into a high-technology product. Printed circuit board manufacturing is highly complicated, requiring large equipment investments and over 50 process steps. Many of the high-speed, miniaturized printed circuit boards are now manufactured in cleanrooms with the same health and safety problems posed by other microelectronics manufacturing. Asia produces three-fourths of the world's printed circuit boards. In Asian countries, glycol ethers are the major solvents used in the printed circuit board industry. Large quantities of hazardous chemicals such as formaldehyde, dimethylformamide, and lead are used by the printed circuit board industry. For decades, chemically intensive and often sloppy manufacturing processes exposed tens of thousands of workers to a large number of chemicals that are now known to be reproductive toxicants and carcinogens. The printed circuit board industry has exposed workers to high doses of toxic metals, solvents, acids, and photolithographic chemicals. Only recently has there been any serious effort to diminish the quantity of lead distributed worldwide by the printed circuit board industry. Billions of electronics products have been discarded in every region of the world. This paper summarizes recent regulatory and enforcement efforts. PMID:16580876

  11. T-junction waveguide-based combining high power microwave beams

    SciTech Connect

    Zhang Qiang; Yuan Chengwei; Liu Lie

    2011-08-15

    Waveguide-based combining microwave beams is an attractive technique for enhancing the output capacities of narrow-band high power microwave devices. A specific T-junction combiner is designed for combining the X/X band microwave beams, and the detailed combining method and experimental results are presented. In the experiments, two microwave sources which can generate gigawatt level microwaves are driven by a single accelerator simultaneously, and their operation frequencies are 9.41 and 9.60 GHz, respectively. The two microwave beams with durations of about 35 ns have been successfully combined, and no breakdown phenomenon occurs.

  12. Structural insights into human 5-lipoxygenase inhibition: combined ligand-based and target-based approach.

    PubMed

    Charlier, Caroline; Hénichart, Jean-Pierre; Durant, François; Wouters, Johan

    2006-01-12

    The human 5-LOX enzyme and its interaction with competitive inhibitors were investigated by means of a combined ligand-based and target-based approach. First, a pharmacophore model was generated for 16 non redox 5-LOX inhibitors with Catalyst (HipHop module). It includes two hydrophobic groups, an aromatic ring, and two hydrogen bond acceptors. The 3D structure of human 5-LOX was then modeled based on the crystal structure of rabbit 15-LOX, and the binding modes of representative ligands were studied by molecular docking. Confrontation of the docking results with the pharmacophore model allowed the weighting of the pharmacophoric features and the integration of structural information. This led to the proposal of an interaction model inside the 5-LOX active site, consisting of four major and two secondary interaction points: on one hand, two hydrophobic groups, an aromatic ring, and a hydrogen bond acceptor, and, on the other hand, an acidic moiety and an additional hydrogen bond acceptor. PMID:16392803

  13. Structural insights into human 5-lipoxygenase inhibition: combined ligand-based and target-based approach.

    PubMed

    Charlier, Caroline; Hénichart, Jean-Pierre; Durant, François; Wouters, Johan

    2006-01-12

    The human 5-LOX enzyme and its interaction with competitive inhibitors were investigated by means of a combined ligand-based and target-based approach. First, a pharmacophore model was generated for 16 non redox 5-LOX inhibitors with Catalyst (HipHop module). It includes two hydrophobic groups, an aromatic ring, and two hydrogen bond acceptors. The 3D structure of human 5-LOX was then modeled based on the crystal structure of rabbit 15-LOX, and the binding modes of representative ligands were studied by molecular docking. Confrontation of the docking results with the pharmacophore model allowed the weighting of the pharmacophoric features and the integration of structural information. This led to the proposal of an interaction model inside the 5-LOX active site, consisting of four major and two secondary interaction points: on one hand, two hydrophobic groups, an aromatic ring, and a hydrogen bond acceptor, and, on the other hand, an acidic moiety and an additional hydrogen bond acceptor.

  14. Synergy of Arbekacin-based Combinations Against Vancomycin Hetero-intermediate Staphylococcus aureus

    PubMed Central

    Lee, Ji-Young; Oh, Won Sup; Ko, Kwan Soo; Heo, Sang Taek; Moon, Chi Sook; Ki, Hyun Kyun; Kiem, Sungmin; Peck, Kyong Ran

    2006-01-01

    This study was undertaken to evaluate the in vitro activities of arbekacin-based combination regimens against vancomycin hetero-intermediate Staphylococcus aureus (hetero-VISA). Combinations of arbekacin with vancomycin, rifampin, ampicillin-sulbactam, teicoplanin, or quinipristin-dalfopristin against seven hetero-VISA strains and two methicillin-resistant S. aureus strains were evaluated by the time-kill assay. The combinations of arbekacin with vancomycin, teicoplanin, or ampicillin-sulbactam showed the synergistic interaction against hetero-VISA strains. Data suggest that these arbekacin-based combination regimens may be useful candidates for treatment options of hetero-VISA infections. PMID:16614499

  15. Testing conditions in shock-based contextual fear conditioning influence both the behavioral responses and the activation of circuits potentially involved in contextual avoidance.

    PubMed

    Viellard, Juliette; Baldo, Marcus Vinicius C; Canteras, Newton Sabino

    2016-12-15

    Previous studies from our group have shown that risk assessment behaviors are the primary contextual fear responses to predatory and social threats, whereas freezing is the main contextual fear response to physically harmful events. To test contextual fear responses to a predator or aggressive conspecific threat, we developed a model that involves placing the animal in an apparatus where it can avoid the threat-associated environment. Conversely, in studies that use shock-based fear conditioning, the animals are usually confined inside the conditioning chamber during the contextual fear test. In the present study, we tested shock-based contextual fear responses using two different behavioral testing conditions: confining the animal in the conditioning chamber or placing the animal in an apparatus with free access to the conditioning compartment. Our results showed that during the contextual fear test, the animals confined to the shock chamber exhibited significantly more freezing. In contrast, the animals that could avoid the conditioning compartment displayed almost no freezing and exhibited risk assessment responses (i.e., crouch-sniff and stretch postures) and burying behavior. In addition, the animals that were able to avoid the shock chamber had increased Fos expression in the juxtadorsomedial lateral hypothalamic area, the dorsomedial part of the dorsal premammillary nucleus and the lateral and dorsomedial parts of the periaqueductal gray, which are elements of a septo/hippocampal-hypothalamic-brainstem circuit that is putatively involved in mediating contextual avoidance. Overall, the present findings show that testing conditions significantly influence both behavioral responses and the activation of circuits involved in contextual avoidance. PMID:27544875

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

    PubMed

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

    2012-10-23

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

  17. Hairpin assembly circuit-based fluorescence cooperative amplification strategy for enzyme-free and label-free detection of small molecule.

    PubMed

    Feng, Chunjing; Zhu, Jing; Sun, Jiewei; Jiang, Wei; Wang, Lei

    2015-10-01

    Here, we developed an enzyme-free, label-free, and sensitive fluorescence cooperative amplification strategy based on a hairpin assembly circuit which coupled catalytic hairpin assembly (CHA) with hybridization chain reaction (HCR) for small molecule adenosine. A double-strand DNA probe with aptamer-catalysis strand (Apt-C) and inhibit strand (Inh) was designed for adenosine recognition and signal transduction which was named as Apt-C/Inh. Hairpins H1 and H2 were employed for constructing the CHA, and hairpins H3 and H4 for the HCR. Through the binding of adenosine and the Apt-C, the Inh was released from the Apt-C/Inh. Then the free Apt-C initiated the CHA through successively opening H1 and H2, generating H1/H2 complex and recyclable Apt-C. Next, the released Apt-C entered another CHA cycle, and the H1/H2 complex further initiated the HCR of H3 and H4 which induced the formation of the concatemers of H3/H4 complex. Such a process brought the two ends of hairpins H3 into close proximity, yielding numerous integrated G-quadruplexes which were initially sequestered in the stem and two terminals of H3. Finally, N-methyl mesoporphyrin IX (NMM) was added to generate an enhanced fluorescence signal. In the proposed strategy, driven only by the energy from hybridization, one target could trigger multiple HCR events via CHA-based target-cycle, leading to a remarkable enzyme-free amplification for adenosine. The detection limit could achieve as low as 9.7 × 10(-7) mol L(-1). Furthermore, G-quadruplexes were applied to construct label-free hairpin assembly circuit, which made it more simple and cost-effective. The satisfactory recoveries were obtained when detecting adenosine in spiked human serum and urine samples, demonstrating the feasibility of this detection strategy in biological samples.

  18. A novel offset cancellation based on parasitic-insensitive switched-capacitor sensing circuit for the out-of-plane single-Gimbaled decoupled CMOS-MEMS gyroscope.

    PubMed

    Chang, Ming-Hui; Huang, Han-Pang

    2013-03-14

    This paper presents a novel parasitic-insensitive switched-capacitor (PISC) sensing circuit design in order to obtain high sensitivity and ultra linearity and reduce the parasitic effect for the out-of-plane single-gimbaled decoupled CMOS-MEMS gyroscope (SGDG). According to the simulation results, the proposed PISC circuit has better sensitivity and high linearity in a wide dynamic range. Experimental results also show a better performance. In addition, the PISC circuit can use signal processing to cancel the offset and noise. Thus, this circuit is very suitable for gyroscope measurement.

  19. A novel offset cancellation based on parasitic-insensitive switched-capacitor sensing circuit for the out-of-plane single-Gimbaled decoupled CMOS-MEMS gyroscope.

    PubMed

    Chang, Ming-Hui; Huang, Han-Pang

    2013-01-01

    This paper presents a novel parasitic-insensitive switched-capacitor (PISC) sensing circuit design in order to obtain high sensitivity and ultra linearity and reduce the parasitic effect for the out-of-plane single-gimbaled decoupled CMOS-MEMS gyroscope (SGDG). According to the simulation results, the proposed PISC circuit has better sensitivity and high linearity in a wide dynamic range. Experimental results also show a better performance. In addition, the PISC circuit can use signal processing to cancel the offset and noise. Thus, this circuit is very suitable for gyroscope measurement. PMID:23493122

  20. Ionization tube simmer current circuit

    DOEpatents

    Steinkraus, R.F. Jr.

    1994-12-13

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

  1. Ionization tube simmer current circuit

    DOEpatents

    Steinkraus, Jr., Robert F.

    1994-01-01

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

  2. Universal discrete Fourier optics RF photonic integrated circuit architecture.

    PubMed

    Hall, Trevor J; Hasan, Mehedi

    2016-04-01

    This paper describes a coherent electro-optic circuit architecture that generates a frequency comb consisting of N spatially separated orders using a generalised Mach-Zenhder interferometer (MZI) with its N × 1 combiner replaced by an optical N × N Discrete Fourier Transform (DFT). Advantage may be taken of the tight optical path-length control, component and circuit symmetries and emerging trimming algorithms offered by photonic integration in any platform that offers linear electro-optic phase modulation such as LiNbO3, silicon, III-V or hybrid technology. The circuit architecture subsumes all MZI-based RF photonic circuit architectures in the prior art given an appropriate choice of output port(s) and dimension N although the principal application envisaged is phase correlated subcarrier generation for all optical orthogonal frequency division multiplexing. A transfer matrix approach is used to model the operation of the architecture. The predictions of the model are validated by simulations performed using an industry standard software tool. Implementation is found to be practical.

  3. Universal discrete Fourier optics RF photonic integrated circuit architecture.

    PubMed

    Hall, Trevor J; Hasan, Mehedi

    2016-04-01

    This paper describes a coherent electro-optic circuit architecture that generates a frequency comb consisting of N spatially separated orders using a generalised Mach-Zenhder interferometer (MZI) with its N × 1 combiner replaced by an optical N × N Discrete Fourier Transform (DFT). Advantage may be taken of the tight optical path-length control, component and circuit symmetries and emerging trimming algorithms offered by photonic integration in any platform that offers linear electro-optic phase modulation such as LiNbO3, silicon, III-V or hybrid technology. The circuit architecture subsumes all MZI-based RF photonic circuit architectures in the prior art given an appropriate choice of output port(s) and dimension N although the principal application envisaged is phase correlated subcarrier generation for all optical orthogonal frequency division multiplexing. A transfer matrix approach is used to model the operation of the architecture. The predictions of the model are validated by simulations performed using an industry standard software tool. Implementation is found to be practical. PMID:27137048

  4. A Virtual Circuits Lab

    ERIC Educational Resources Information Center

    Vick, Matthew E.

    2010-01-01

    The University of Colorado's Physics Education Technology (PhET) website offers free, high-quality simulations of many physics experiments that can be used in the classroom. The Circuit Construction Kit, for example, allows students to safely and constructively play with circuit components while learning the mathematics behind many circuit…

  5. Computer circuit card puller

    NASA Technical Reports Server (NTRS)

    Sawyer, R. V.; Szuwalski, B. (Inventor)

    1981-01-01

    The invention generally relates to hand tools, and more particularly to an improved device for facilitating removal of printed circuit cards from a card rack characterized by longitudinal side rails arranged in a mutually spaced parallelism and a plurality of printed circuit cards extended between the rails of the rack.

  6. Completing a Simple Circuit.

    ERIC Educational Resources Information Center

    Slater, Timothy F.; Adams, Jeffrey P.; Brown, Thomas R.

    2000-01-01

    Students have problems successfully arranging an electric circuit to make the bulb produce light. Investigates the percentage of students able to complete a circuit with a given apparatus, and the effects of prior experience on student success. Recommends hands-on activities at the elementary and secondary school levels. (Contains 14 references.)…

  7. Understanding Simple Circuits

    ERIC Educational Resources Information Center

    Mant, Jenny; Wilson, Helen

    2007-01-01

    Many envisage electricity as the "power" to "do things." They know that electricity needs "circuits" and that something is "flowing" in the circuits, but they are not sure what or why. Words such as "current" and "voltage" are part of electricity but their meaning, and the difference between them, is not always clear. In this article, the authors…

  8. Interconnections for fluidic circuits

    NASA Technical Reports Server (NTRS)

    Mangion, C.

    1972-01-01

    Circuit elements are grouped on functional basis in rectangular two-dimensional planar arrays or modules. Another interconnection method brings all connections out to module edge. For smaller fluidic circuits, manifold and interconnections are fabricated as single blocks. Advantages of methods are given.

  9. Liquid detection circuit

    DOEpatents

    Regan, Thomas O.

    1987-01-01

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

  10. Piezo-optomechanical circuits

    NASA Astrophysics Data System (ADS)

    Coimbatore Balram, Krishna; Davanco, Marcelo; Ilic, B. Robert; Srinivasan, Kartik

    Coherent links between the optical, radio frequency (RF), and mechanical domains are critical for applications ranging from quantum state transfer between the RF and optical domains to signal processing in the acoustic domain for microwave photonics. We develop such a piezo optomechanical circuit platform in GaAs, in which localized and interacting 1550 nm photons and 2.4 GHz phonons are combined with photonic and phononic waveguides. GaAs allows us to exploit the photoelastic effect to engineer cavities with strong optomechanical coupling (g0/2 π ~ 1.1 MHz) and the piezoelectric effect to couple RF fields to mechanical motion through surface acoustic waves, which are routed on-chip using phononic crystal waveguides. This platform enables optical readout of electrically-injected mechanical states with an average coherent intracavity phonon number as small as ~0.05 and the ability to drive mechanical motion with equal facility through either the optical or electrical channel. This is used to demonstrate a novel acoustic wave interference effect in which optically-driven motion is completely cancelled by electrically-driven motion, and vice versa. As an application of this, we present time-domain measurements of optically-controlled acoustic pulse propagation. Secondary Affiliation is Maryland Nanocenter, University of Maryland, College Park, MD.

  11. 24 CFR 3280.805 - Branch circuits required.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Branch circuits required. 3280.805... Branch circuits required. Link to an amendment published at 78 FR 73991, Dec. 9, 2013. (a) The number of branch circuits required shall be determined in accordance with the following: (1) Lighting, based on...

  12. Progress in organic integrated circuit manufacture

    NASA Astrophysics Data System (ADS)

    Taylor, D. Martin

    2016-02-01

    This review article focuses on the development of processes for the manufacture of organic electronic circuits. Beginning with the first report of an organic transistor it highlights the key developments leading to the successful manufacture of microprocessors and other complex circuits incorporating organic transistors. Both batch processing (based on silicon integrated circuit technology) as well as mass-printing, roll-to-roll (R2R) approaches are discussed. Currently, the best circuit performances are achieved using batch processing. It is suggested that an emerging, large mass-market for electronic tags may dictate that R2R manufacture will likely be required to meet the high throughput rates needed. However, significant improvements in resolution and registration are necessary to achieve increased circuit operating speeds.

  13. State Equations for Active Circuits with Memristors

    NASA Astrophysics Data System (ADS)

    Hasler, Martin

    2013-01-01

    Nonlinear dynamic circuits including memristors are considered. Graph-theoretical criteria are given as sufficient conditions for the existence of global state equations, with the capacitor and memristor charges as state variables (for convenience we do not consider inductors here). They are based on earlier work on circuits without memristors. Global state equations in these charges fail to exist when the charges are dependent or when singular points are present, socalled impasse points. The values of state variables at initial time uniquely determine a solution. Therefore, even for numerical circuit analysis that in general does not use state equations, the determination of a set of state variables is important, and to know whether, with the "canonical candidates" for states, global state equations exist, is the first and most important step. The graph-theoretical criteria are easy to check directly for simple circuits. We give a few simple examples that illustrate the various cases. Larger circuits have to be examined by combinatorial algorithms.

  14. Depth-optimized reversible circuit synthesis

    NASA Astrophysics Data System (ADS)

    Arabzadeh, Mona; Saheb Zamani, Morteza; Sedighi, Mehdi; Saeedi, Mehdi

    2013-04-01

    In this paper, simultaneous reduction of circuit depth and synthesis cost of reversible circuits in quantum technologies with limited interaction is addressed. We developed a cycle-based synthesis algorithm which uses negative controls and limited distance between gate lines. To improve circuit depth, a new parallel structure is introduced in which before synthesis a set of disjoint cycles are extracted from the input specification and distributed into some subsets. The cycles of each subset are synthesized independently on different sets of ancillae. Accordingly, each disjoint set can be synthesized by different synthesis methods. Our analysis shows that the best worst-case synthesis cost of reversible circuits in the linear nearest neighbor architecture is improved by the proposed approach. Our experimental results reveal the effectiveness of the proposed approach to reduce cost and circuit depth for several benchmarks.

  15. Simple circuit for pacing hearts of experimental animals.

    PubMed

    Freeman, G L; Colston, J T

    1992-06-01

    In this paper we describe a simple pacing circuit which can be used to drive the heart over a wide range of rates. The circuit is an astable multivibrator, based on an LM555 integrated circuit. It is powered by a 9-V battery and is small enough for use in rabbits. The circuit is easily constructed and inexpensive, making it attractive for numerous applications in cardiovascular research.

  16. Students' Errors in Solving the Permutation and Combination Problems Based on Problem Solving Steps of Polya

    ERIC Educational Resources Information Center

    Sukoriyanto; Nusantara, Toto; Subanji; Chandra, Tjang Daniel

    2016-01-01

    This article was written based on the results of a study evaluating students' errors in problem solving of permutation and combination in terms of problem solving steps according to Polya. Twenty-five students were asked to do four problems related to permutation and combination. The research results showed that the students still did a mistake in…

  17. Compensated gain control circuit for buck regulator command charge circuit

    DOEpatents

    Barrett, D.M.

    1996-11-05

    A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit. 5 figs.

  18. Compensated gain control circuit for buck regulator command charge circuit

    DOEpatents

    Barrett, David M.

    1996-01-01

    A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit.

  19. Spatial and planar optical circuit for flexible ROADM

    NASA Astrophysics Data System (ADS)

    Shikama, Kota; Ikuma, Yuichiro; Suzuki, Kenya; Takahashi, Tetsuo

    2016-02-01

    A high port count wavelength selective switch (HPC-WSS) is a key component when constructing colorless, directionless, and contentionless ROADM because it provides increased flexibility and scalability. We have been developing HPC-WSSs by combining a waveguide-based optical frontend and free-space optics, which we call a spatial and planar optical circuit (SPOC) platform. In this paper, we present an HPC-WSS and a low-loss transponder aggregator based on a SPOC platform, and we also describe the reliability of the frontend, which is a key enabler for the SPOC platform.

  20. Nonlinear full-wave-interaction analysis of a gyrotron-traveling-wave-tube amplifier based on a lossy dielectric-lined circuit

    SciTech Connect

    Du Chaohai; Liu Pukun

    2010-03-15

    The stability of the millimeter-wave gyrotron-traveling-wave-tube (gyro-TWT) amplifier can be effectively improved via controlling the propagation characteristics of the operating modes using lossy dielectric-lined (DL) waveguide. Self-consistent nonlinear theory of the electron cyclotron maser (ECM) interaction in lossy DL circuit is developed based on a full-wave study of the propagation characteristics of the DL waveguide. This nonlinear theory fully takes into consideration the waveguide structure and the lossy dielectric characteristics. It is capable of accurately calculating the ECM instability between a cyclotron harmonic and a circular polarized mode, and effectively predicting the nonlinear stability of the DL waveguide-based gyro-TWT. Systematic investigation of a Ka-band TE{sub 01} mode DL waveguide-based gyro-TWT is carried out, and numerical calculation reveals a series of interesting results. This work provides a basic theoretical tool for further exploring the application of the lossy DL waveguide in millimeter-wave gyro-TWTs.

  1. Whole-body aerobic resistance training circuit improves aerobic fitness and muscle strength in sedentary young females.

    PubMed

    Myers, Terrence R; Schneider, Matthew G; Schmale, Matthew S; Hazell, Tom J

    2015-06-01

    This study aimed to determine whether a time-effective whole-body aerobic resistance training circuit using only body weight exercises is as effective in improving aerobic and anaerobic fitness, as well as muscular strength and endurance as a traditional concurrent style training combining resistance and endurance training. Thirty-four sedentary females (20.9 ± 3.2 years; 167.6 ± 6.4 cm; 65.0 ± 15.2 kg) were assigned to either: (a) a combined resistance and aerobic exercise group (COMBINED; n = 17) or (b) a circuit-based whole-body aerobic resistance training circuit group (CIRCUIT; n = 17). Training was 3 days per week for 5 weeks. Pre- and post-training measures included a (Equation is included in full-text article.)test, anaerobic Wingate cycling test, and muscular strength and endurance tests. After training, (Equation is included in full-text article.)improved with CIRCUIT by 11% (p = 0.015), with no change for COMBINED (p = 0.375). Both relative peak power output and relative average power output improved with CIRCUIT by 5% (p = 0.027) and 3.2% (p = 0.006), respectively, and with COMBINED by 5.3% (p = 0.025) and 5.1% (p = 0.003). Chest and hamstrings 1 repetition maximum (1RM) improved with CIRCUIT by 20.6% (p = 0.011) and 8.3% (p = 0.022) and with COMBINED by 35.6% (p < 0.001) and 10.2% (p = 0.004), respectively. Only the COMBINED group improved back (11.7%; p = 0.017) and quadriceps (9.6%; p = 0.006) 1RM. The COMBINED group performed more repetitions at 60% of their pretraining 1RM for back (10.0%; p = 0.006) and hamstring (23.3%; p = 0.056) vs. CIRCUIT. Our results suggest that a circuit-based whole-body aerobic resistance training program can elicit a greater cardiorespiratory response and similar muscular strength gains with less time commitment compared with a traditional resistance training program combined with aerobic exercise.

  2. Understanding the behaviour of infinite ladder circuits

    NASA Astrophysics Data System (ADS)

    Ucak, C.; Yegin, K.

    2008-11-01

    Infinite ladder circuits are often encountered in undergraduate electrical engineering and physics curricula when dealing with series and parallel combination of impedances, as a part of filter design or wave propagation on transmission lines. The input impedance of such infinite ladder circuits is derived by assuming that the input impedance does not change when a new block of impedance is added. However, the impedance derived from this assumption may lead to incorrect conclusions if it is not treated carefully. Sometimes, in the literature, the input impedance behaviour of infinite ladder circuits is referred to as a paradox, leaving students and educators in doubt. This study intends to clarify this confusion and help to better comprehend the behaviour of the input impedance of infinite ladder circuits.

  3. Subtyping of Gliomaby Combining Gene Expression and CNVs Data Based on a Compressive Sensing Approach

    PubMed Central

    Tang, Wenlong; Cao, Hongbao; Zhang, Ji-Gang; Duan, Junbo; Lin, Dongdong; Wang, Yu-Ping

    2013-01-01

    It is realized that a combined analysis of different types of genomic measurements tends to give more reliable classification results. However, how to efficiently combine data with different resolutions is challenging. We propose a novel compressed sensing based approach for the combined analysis of gene expression and copy number variants data for the purpose of subtyping six types of Gliomas. Experimental results show that the proposed combined approach can substantially improve the classification accuracy compared to that of using either of individual data type. The proposed approach can be applicable to many other types of genomic data. PMID:25267935

  4. Polymorphic Electronic Circuits

    NASA Technical Reports Server (NTRS)

    Stoica, Adrian

    2004-01-01

    Polymorphic electronics is a nascent technological discipline that involves, among other things, designing the same circuit to perform different analog and/or digital functions under different conditions. For example, a circuit can be designed to function as an OR gate or an AND gate, depending on the temperature (see figure). Polymorphic electronics can also be considered a subset of polytronics, which is a broader technological discipline in which optical and possibly other information- processing systems could also be designed to perform multiple functions. Polytronics is an outgrowth of evolvable hardware (EHW). The basic concepts and some specific implementations of EHW were described in a number of previous NASA Tech Briefs articles. To recapitulate: The essence of EHW is to design, construct, and test a sequence of populations of circuits that function as incrementally better solutions of a given design problem through the selective, repetitive connection and/or disconnection of capacitors, transistors, amplifiers, inverters, and/or other circuit building blocks. The evolution is guided by a search-and-optimization algorithm (in particular, a genetic algorithm) that operates in the space of possible circuits to find a circuit that exhibits an acceptably close approximation of the desired functionality. The evolved circuits can be tested by computational simulation (in which case the evolution is said to be extrinsic), tested in real hardware (in which case the evolution is said to be intrinsic), or tested in random sequences of computational simulation and real hardware (in which case the evolution is said to be mixtrinsic).

  5. Three-visible-light wave combiner based on photonic crystal waveguides.

    PubMed

    Liu, Dingwen; Sun, Yiling; Ouyang, Zhengbiao

    2014-07-20

    We present a three-visible-light wave combiner based on two-dimensional photonic crystal waveguides whose widths are not integral multiples of the lattice period. The proposed device consists of two cascaded directional couplers. It combines three visible light waves with different wavelengths from three input ports into a single output port. As an example, a combiner for combining light waves of 635, 532, and 488 nm, which are commonly used as the three primary colors in laser display systems, is designed and demonstrated through the finite-difference time-domain method. The results show that the proposed device can perform efficient synthesis for three visible light waves with transmittance exceeding 89% for each wavelength and high ability in preventing the backward coupling of waves from different waveguides. The method for designing the combiner is useful for designing other waveguide couplers based on photonic crystals made of dispersion materials.

  6. Test Structures For Bumpy Integrated Circuits

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G.; Sayah, Hoshyar R.

    1989-01-01

    Cross-bridge resistors added to comb and serpentine patterns. Improved combination of test structures built into integrated circuit used to evaluate design rules, fabrication processes, and quality of interconnections. Consist of meshing serpentines and combs, and cross bridge. Structures used to make electrical measurements revealing defects in design or fabrication. Combination of test structures includes three comb arrays, two serpentine arrays, and cross bridge. Made of aluminum or polycrystalline silicon, depending on material in integrated-circuit layers evaluated. Aluminum combs and serpentine arrays deposited over steps made by polycrystalline silicon and diffusion layers, while polycrystalline silicon versions of these structures used to cross over steps made by thick oxide layer.

  7. Additive manufacturing of hybrid circuits

    DOE PAGES

    Bell, Nelson S.; Sarobol, Pylin; Cook, Adam; Clem, Paul G.; Keicher, David M.; Hirschfeld, Deidre; Hall, Aaron Christopher

    2016-03-26

    There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects.more » Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. As a result, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.« less

  8. Electrical circuit for data reduction

    SciTech Connect

    Kronberg, J.W.

    1991-12-31

    This invention is comprised of an electrical circuit for determining characteristic voltages, such as maximum, minimum, average and root mean squared voltages, of a time-varying electrical signal. The circuit comprises a positive and a negative peak detector that feed the positive and negative voltage peaks detected in each of a series of time intervals into a solid-state multiplexer controlled by a process controller. The time intervals are generated by the process controller in combination with a clocking, circuit. The multiplexer applies the positive and negative peak voltages to a set of four capacitors, apply the positive peak to one capacitor during one interval and then the negative peak to that capacitor in a subsequent interval so that each capacitor is alternatingly accumulating a positive peak then a negative peak to obviate the need for resetting each capacitor. After the positive peak voltage is applied to one capacitor, the connection is switched during the next interval for reading the negative peak voltage, then switched again for applying, a negative peak voltage, then switched once more for reading the negative peak voltage, the multiplexer serving, as a solid state commutator for switching the electrical connection. Alternatively, peak maximum and minimum voltage detectors may be replaced with circuitry designed to obtain the additional characteristic voltages desired in each interval.

  9. Monolithic microwave integrated circuits

    NASA Astrophysics Data System (ADS)

    Pucel, R. A.

    Monolithic microwave integrated circuits (MMICs), a new microwave technology which is expected to exert a profound influence on microwave circuit designs for future military systems as well as for the commercial and consumer markets, is discussed. The book contains an historical discussion followed by a comprehensive review presenting the current status in the field. The general topics of the volume are: design considerations, materials and processing considerations, monolithic circuit applications, and CAD, measurement, and packaging techniques. All phases of MMIC technology are covered, from design to testing.

  10. DIFFERENTIAL FAULT SENSING CIRCUIT

    DOEpatents

    Roberts, J.H.

    1961-09-01

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

  11. NLLSS: Predicting Synergistic Drug Combinations Based on Semi-supervised Learning

    PubMed Central

    Chen, Ming; Wang, Quanxin; Zhang, Lixin; Yan, Guiying

    2016-01-01

    Fungal infection has become one of the leading causes of hospital-acquired infections with high mortality rates. Furthermore, drug resistance is common for fungus-causing diseases. Synergistic drug combinations could provide an effective strategy to overcome drug resistance. Meanwhile, synergistic drug combinations can increase treatment efficacy and decrease drug dosage to avoid toxicity. Therefore, computational prediction of synergistic drug combinations for fungus-causing diseases becomes attractive. In this study, we proposed similar nature of drug combinations: principal drugs which obtain synergistic effect with similar adjuvant drugs are often similar and vice versa. Furthermore, we developed a novel algorithm termed Network-based Laplacian regularized Least Square Synergistic drug combination prediction (NLLSS) to predict potential synergistic drug combinations by integrating different kinds of information such as known synergistic drug combinations, drug-target interactions, and drug chemical structures. We applied NLLSS to predict antifungal synergistic drug combinations and showed that it achieved excellent performance both in terms of cross validation and independent prediction. Finally, we performed biological experiments for fungal pathogen Candida albicans to confirm 7 out of 13 predicted antifungal synergistic drug combinations. NLLSS provides an efficient strategy to identify potential synergistic antifungal combinations. PMID:27415801

  12. NLLSS: Predicting Synergistic Drug Combinations Based on Semi-supervised Learning.

    PubMed

    Chen, Xing; Ren, Biao; Chen, Ming; Wang, Quanxin; Zhang, Lixin; Yan, Guiying

    2016-07-01

    Fungal infection has become one of the leading causes of hospital-acquired infections with high mortality rates. Furthermore, drug resistance is common for fungus-causing diseases. Synergistic drug combinations could provide an effective strategy to overcome drug resistance. Meanwhile, synergistic drug combinations can increase treatment efficacy and decrease drug dosage to avoid toxicity. Therefore, computational prediction of synergistic drug combinations for fungus-causing diseases becomes attractive. In this study, we proposed similar nature of drug combinations: principal drugs which obtain synergistic effect with similar adjuvant drugs are often similar and vice versa. Furthermore, we developed a novel algorithm termed Network-based Laplacian regularized Least Square Synergistic drug combination prediction (NLLSS) to predict potential synergistic drug combinations by integrating different kinds of information such as known synergistic drug combinations, drug-target interactions, and drug chemical structures. We applied NLLSS to predict antifungal synergistic drug combinations and showed that it achieved excellent performance both in terms of cross validation and independent prediction. Finally, we performed biological experiments for fungal pathogen Candida albicans to confirm 7 out of 13 predicted antifungal synergistic drug combinations. NLLSS provides an efficient strategy to identify potential synergistic antifungal combinations. PMID:27415801

  13. NLLSS: Predicting Synergistic Drug Combinations Based on Semi-supervised Learning.

    PubMed

    Chen, Xing; Ren, Biao; Chen, Ming; Wang, Quanxin; Zhang, Lixin; Yan, Guiying

    2016-07-01

    Fungal infection has become one of the leading causes of hospital-acquired infections with high mortality rates. Furthermore, drug resistance is common for fungus-causing diseases. Synergistic drug combinations could provide an effective strategy to overcome drug resistance. Meanwhile, synergistic drug combinations can increase treatment efficacy and decrease drug dosage to avoid toxicity. Therefore, computational prediction of synergistic drug combinations for fungus-causing diseases becomes attractive. In this study, we proposed similar nature of drug combinations: principal drugs which obtain synergistic effect with similar adjuvant drugs are often similar and vice versa. Furthermore, we developed a novel algorithm termed Network-based Laplacian regularized Least Square Synergistic drug combination prediction (NLLSS) to predict potential synergistic drug combinations by integrating different kinds of information such as known synergistic drug combinations, drug-target interactions, and drug chemical structures. We applied NLLSS to predict antifungal synergistic drug combinations and showed that it achieved excellent performance both in terms of cross validation and independent prediction. Finally, we performed biological experiments for fungal pathogen Candida albicans to confirm 7 out of 13 predicted antifungal synergistic drug combinations. NLLSS provides an efficient strategy to identify potential synergistic antifungal combinations.

  14. Capacity-loss diagnostic and life-time prediction in lithium-ion batteries: Part 1. Development of a capacity-loss diagnostic method based on open-circuit voltage analysis

    NASA Astrophysics Data System (ADS)

    Wang, Tiansi; Pei, Lei; Wang, Tingting; Lu, Rengui; Zhu, Chunbo

    2016-01-01

    Effective capacity-loss diagnosis and life-time prediction are the foundations of battery second-use technology and will play an important role in the development of the new energy industry. Of the two, the capacity-loss diagnostic, as a precondition of the life-time prediction, needs to be studied first. Performing a capacity-loss diagnosis for an aging cell consists of finding the decisive degradation mechanisms for the cell's capacity degradation. Because a cell's capacity just equals the span of the open-circuit voltage (OCV), when suspect degradation mechanisms affect a cell's capacity, they will leave corresponding and particular clues in the OCV curve. Taking a cell's OCV as the diagnostic indicator, a multi-mechanistic and non-destructive diagnostic method is developed in this paper. To establish an unambiguous relationship between OCV changes and the combinations of the decisive mechanisms, all the possible OCV changes under various aging situations are systematically analyzed based on a novel simultaneous coordinate system, in which the effects of each suspect capacity-loss mechanism on the OCV curve can be clearly represented. As a summary of the analysis results, a straightforward diagnostic flowchart is presented. By following the flowchart, an aging cell can be diagnosed within three steps by observation of the OCV changes.

  15. A Historical Perspective on the Role of Functional Lines of Block in the Re-entrant Circuit of Ventricular Tachycardia.

    PubMed

    Proietti, Riccardo; Roux, Jean-Francois; Verma, Atul; Alturki, Ahmed; Bernier, Martin L; Essebag, Vidal

    2016-05-01

    The ablation strategy for ventricular tachycardia (VT) rapidly evolved from an entrainment mapping approach for identification of the critical isthmus of the re-entrant circuit during monomorphic VT, toward a substrate-based approach aiming to ablate surrogate markers of the circuit during sinus rhythm in hemodynamically nontolerated and polymorphic VT. The latter approach implies an assumption that the circuits responsible for the arrhythmia are anatomical or fixed, and present during sinus rhythm. Accordingly, the lines of block delimiting the channels of the circuits are often considered fixed, although there is evidence that they are functional or more frequently a combination of fixed and functional. The electroanatomical substrate-based approach to VT ablation performed during sinus rhythm is increasingly adopted in clinical practice and often described as scar homogenization, scar dechanneling, or core isolation. However, whether the surrogate markers of the VT circuit during sinus rhythm match the circuit during arrhythmias remains to be fully demonstrated. The myocardial scar is a heterogeneous electrophysiological milieu with complex arrhythmogenic mechanisms that potentially coexist simultaneously. Moreover, the scar consists of different areas of diverse refractoriness and conduction. It can be misleading to limit the arrhythmogenic perspective of the myocardial scar to fixed or anatomical barriers held responsible for the re-entry circuit. Greater understanding of the role of functional lines of block in VT and the validity of the surrogate targets being ablated is necessary to further improve the technique and outcome of VT ablation.

  16. Displacement Damage in Bipolar Linear Integrated Circuits

    NASA Technical Reports Server (NTRS)

    Rax, B. G.; Johnston, A. H.; Miyahira, T.

    2000-01-01

    Although many different processes can be used to manufacture linear integrated circuits, the process that is used for most circuits is optimized for high voltage -- a total power supply voltage of about 40 V -- and low cost. This process, which has changed little during the last twenty years, uses lateral and substrate p-n-p transistors. These p-n-p transistors have very wide base regions, increasing their sensitivity to displacement damage from electrons and protons. Although displacement damage effects can be easily treated for individual transistors, the net effect on linear circuits can be far more complex because circuit operation often depends on the interaction of several internal transistors. Note also that some circuits are made with more advanced processes with much narrower base widths. Devices fabricated with these newer processes are not expected to be significantly affected by displacement damage for proton fluences below 1 x 10(exp 12) p/sq cm. This paper discusses displacement damage in linear integrated circuits with more complex failure modes than those exhibited by simpler devices, such as the LM111 comparator, where the dominant response mode is gain degradation of the input transistor. Some circuits fail catastrophically at much lower equivalent total dose levels compared to tests with gamma rays. The device works satisfactorily up to nearly 1 Mrad(Si) when it is irradiated with gamma rays, but fails catastrophically between 50 and 70 krad(Si) when it is irradiated with protons.

  17. Image-Based Airborne Sensors: A Combined Approach for Spectral Signatures Classification through Deterministic Simulated Annealing

    PubMed Central

    Guijarro, María; Pajares, Gonzalo; Herrera, P. Javier

    2009-01-01

    The increasing technology of high-resolution image airborne sensors, including those on board Unmanned Aerial Vehicles, demands automatic solutions for processing, either on-line or off-line, the huge amountds of image data sensed during the flights. The classification of natural spectral signatures in images is one potential application. The actual tendency in classification is oriented towards the combination of simple classifiers. In this paper we propose a combined strategy based on the Deterministic Simulated Annealing (DSA) framework. The simple classifiers used are the well tested supervised parametric Bayesian estimator and the Fuzzy Clustering. The DSA is an optimization approach, which minimizes an energy function. The main contribution of DSA is its ability to avoid local minima during the optimization process thanks to the annealing scheme. It outperforms simple classifiers used for the combination and some combined strategies, including a scheme based on the fuzzy cognitive maps and an optimization approach based on the Hopfield neural network paradigm. PMID:22399989

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

    NASA Astrophysics Data System (ADS)

    Luo, Yi; Dahmardeh, Masoud; Takahata, Kenichi

    2015-05-01

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

  19. Fabric circuits and method of manufacturing fabric circuits

    NASA Technical Reports Server (NTRS)

    Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Scully, Robert C. (Inventor); Trevino, Robert C. (Inventor); Lin, Greg Y. (Inventor); Fink, Patrick W. (Inventor)

    2011-01-01

    A flexible, fabric-based circuit comprises a non-conductive flexible layer of fabric and a conductive flexible layer of fabric adjacent thereto. A non-conductive thread, an adhesive, and/or other means may be used for attaching the conductive layer to the non-conductive layer. In some embodiments, the layers are attached by a computer-driven embroidery machine at pre-determined portions or locations in accordance with a pre-determined attachment layout before automated cutting. In some other embodiments, an automated milling machine or a computer-driven laser using a pre-designed circuit trace as a template cuts the conductive layer so as to separate an undesired portion of the conductive layer from a desired portion of the conductive layer. Additional layers of conductive fabric may be attached in some embodiments to form a multi-layer construct.

  20. Maximum Temperature Detection System for Integrated Circuits

    NASA Astrophysics Data System (ADS)

    Frankiewicz, Maciej; Kos, Andrzej

    2015-03-01

    The paper describes structure and measurement results of the system detecting present maximum temperature on the surface of an integrated circuit. The system consists of the set of proportional to absolute temperature sensors, temperature processing path and a digital part designed in VHDL. Analogue parts of the circuit where designed with full-custom technique. The system is a part of temperature-controlled oscillator circuit - a power management system based on dynamic frequency scaling method. The oscillator cooperates with microprocessor dedicated for thermal experiments. The whole system is implemented in UMC CMOS 0.18 μm (1.8 V) technology.