WorldWideScience

Sample records for maximum open circuit

  1. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  2. Influence of MoOx interlayer on the maximum achievable open-circuit voltage in organic photovoltaic cells

    Science.gov (United States)

    Zou, Yunlong; Holmes, Russell

    2013-03-01

    Transition metal oxides including molybdenum oxide (MoOx) are characterized by large work functions and deep energy levels relative to the organic semiconductors used in photovoltaic cells (OPVs). These materials have been used in OPVs as interlayers between the indium-tin-oxide anode and the active layers to increase the open-circuit voltage (VOC) and power conversion efficiency. We examine the role of MoOx in determining the maximum achievable VOC in planar heterojunction OPVs based on the donor-acceptor pairing of boron subphthalocyanine chloride (SubPc) and C60. While causing minor changes in VOC at room temperature, the inclusion of MoOx significantly changes the temperature dependence of VOC. Devices containing no interlayer show a maximum VOC\\ of 1.2 V, while devices containing MoOx show no saturation in VOC, reaching a value of >1.4 V at 110 K. We propose that the MoOx-SubPc interface forms a dissociating Schottky junction that provides an additional contribution to VOC at low temperature. Separate measurements of photoluminescence confirm that excitons in SubPc can be quenched by MoOx. Charge transfer at this interface is by hole extraction from SubPc to MoOx, and this mechanism favors donors with a deep highest occupied molecular orbital (HOMO) energy level. Consistent with this expectation, the temperature dependence of VOC for devices constructed using a donor with a shallower HOMO level, e.g. copper phthalocyanine, is independent of the presence of MoOx.

  3. Maximum Temperature Detection System for Integrated Circuits

    Science.gov (United States)

    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.

  4. Tester Detects Steady-Short Or Intermittent-Open Circuits

    Science.gov (United States)

    Anderson, Bobby L.

    1990-01-01

    Momentary open circuits or steady short circuits trigger buzzer. Simple, portable, lightweight testing circuit sounds long-duration alarm when it detects steady short circuit or momentary open circuit in coaxial cable or other two-conductor transmission line. Tester sensitive to discontinuities lasting 10 microseconds or longer. Used extensively for detecting intermittent open shorts in accelerometer and extensometer cables. Also used as ordinary buzzer-type continuity checker to detect steady short or open circuits.

  5. 30 CFR 77.902-1 - Fail safe ground check circuits; maximum voltage.

    Science.gov (United States)

    2010-07-01

    ... voltage. 77.902-1 Section 77.902-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.902-1 Fail safe ground check circuits; maximum voltage. The maximum voltage used for ground check circuits under § 77.902...

  6. Microwatt power consumption maximum power point tracking circuit using an analogue differentiator for piezoelectric energy harvesting

    Science.gov (United States)

    Chew, Z. J.; Zhu, M.

    2015-12-01

    A maximum power point tracking (MPPT) scheme by tracking the open-circuit voltage from a piezoelectric energy harvester using a differentiator is presented in this paper. The MPPT controller is implemented by using a low-power analogue differentiator and comparators without the need of a sensing circuitry and a power hungry controller. This proposed MPPT circuit is used to control a buck converter which serves as a power management module in conjunction with a full-wave bridge diode rectifier. Performance of this MPPT control scheme is verified by using the prototyped circuit to track the maximum power point of a macro-fiber composite (MFC) as the piezoelectric energy harvester. The MFC was bonded on a composite material and the whole specimen was subjected to various strain levels at frequency from 10 to 100 Hz. Experimental results showed that the implemented full analogue MPPT controller has a tracking efficiency between 81% and 98.66% independent of the load, and consumes an average power of 3.187 μW at 3 V during operation.

  7. 30 CFR 77.803-1 - Fail safe ground check circuits; maximum voltage.

    Science.gov (United States)

    2010-07-01

    ... voltage. 77.803-1 Section 77.803-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.803-1 Fail safe ground check circuits; maximum voltage. The maximum voltage used for ground check circuits under § 77.803 shall not...

  8. 30 CFR 75.601-3 - Short circuit protection; dual element fuses; current ratings; maximum values.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection; dual element fuses... Trailing Cables § 75.601-3 Short circuit protection; dual element fuses; current ratings; maximum values. Dual element fuses having adequate current-interrupting capacity shall meet the requirements for short...

  9. Open circuit mouthpiece ventilation: Concise clinical review

    Directory of Open Access Journals (Sweden)

    G. Garuti

    2014-07-01

    Full Text Available In 2013 new “mouthpiece ventilation” modes are being introduced to commercially available portable ventilators. Despite this, there is little knowledge of how to use noninvasive intermittent positive pressure ventilation (NIV as opposed to bi-level positive airway pressure (PAP and both have almost exclusively been reported to have been used via nasal or oro-nasal interfaces rather than via a simple mouthpiece.Non-invasive ventilation is often reported as failing because of airway secretion encumbrance, because of hypercapnia due to inadequate bi-level PAP settings, or poor interface tolerance. The latter can be caused by factors such as excessive pressure on the face from poor fit, excessive oral air leak, anxiety, claustrophobia, and patient-ventilator dys-synchrony. Thus, the interface plays a crucial role in tolerance and effectiveness. Interfaces that cover the nose and/or nose and mouth (oro-nasal are the most commonly used but are more likely to cause skin breakdown and claustrophobia. Most associated drawbacks can be avoided by using mouthpiece NIV. Open-circuit mouthpiece NIV is being used by large populations in some centers for daytime ventilatory support and complements nocturnal NIV via “mask” interfaces for nocturnal ventilatory support. Mouthpiece NIV is also being used for sleep with the mouthpiece fixed in place by a lip-covering flange. Small 15 and 22 mm angled mouthpieces and straw-type mouthpieces are the most commonly used.NIV via mouthpiece is being used as an effective alternative to ventilatory support via tracheostomy tube (TMV and is associated with a reduced risk of pneumonias and other respiratory complications. Its use facilitates “air-stacking” to improve cough, speech, and pulmonary compliance, all of which better maintain quality of life for patients with neuromuscular diseases (NMDs than the invasive alternatives. Considering these benefits and the new availability of mouthpiece

  10. Elements configuration of the open lead test circuit

    Energy Technology Data Exchange (ETDEWEB)

    Fukuzaki, Yumi, E-mail: 14514@sr.kagawa-nct.ac.jp [Advanced course of Electronics, Information and Communication Engineering, National Institute of Technology, Kagawa College, 551 Koda, Mitoyo, Kagawa (Japan); Ono, Akira [Department of Communication Network Engineering, National Institute of Technology, Kagawa College, 551 Koda, Mitoyo, Kagawa (Japan)

    2016-07-06

    In the field of electronics, small electronic devices are widely utilized because they are easy to carry. The devices have various functions by user’s request. Therefore, the lead’s pitch or the ball’s pitch have been narrowed and high-density printed circuit board has been used in the devices. Use of the ICs which have narrow lead pitch makes normal connection difficult. When logic circuits in the devices are fabricated with the state-of-the-art technology, some faults have occurred more frequently. It can be divided into types of open faults and short faults. We have proposed a new test method using a test circuit in the past. This paper propose elements configuration of the test circuit.

  11. Elements configuration of the open lead test circuit

    International Nuclear Information System (INIS)

    Fukuzaki, Yumi; Ono, Akira

    2016-01-01

    In the field of electronics, small electronic devices are widely utilized because they are easy to carry. The devices have various functions by user’s request. Therefore, the lead’s pitch or the ball’s pitch have been narrowed and high-density printed circuit board has been used in the devices. Use of the ICs which have narrow lead pitch makes normal connection difficult. When logic circuits in the devices are fabricated with the state-of-the-art technology, some faults have occurred more frequently. It can be divided into types of open faults and short faults. We have proposed a new test method using a test circuit in the past. This paper propose elements configuration of the test circuit.

  12. A high open-circuit voltage gallium nitride betavoltaic microbattery

    International Nuclear Information System (INIS)

    Cheng, Zaijun; Chen, Xuyuan; San, Haisheng; Feng, Zhihong; Liu, Bo

    2012-01-01

    A high open-circuit voltage betavoltaic microbattery based on a gallium nitride (GaN) p–i–n homojunction is demonstrated. As a beta-absorbing layer, the low electron concentration of the n-type GaN layer is achieved by the process of Fe compensation doping. Under the irradiation of a planar solid 63 Ni source with activity of 0.5 mCi, the open-circuit voltage of the fabricated microbattery with 2 × 2 mm 2 area reaches as much as 1.64 V, which is the record value reported for betavoltaic batteries with 63 Ni source, the short-circuit current was measured as 568 pA and the conversion effective of 0.98% was obtained. The experimental results suggest that GaN is a high-potential candidate for developing the betavoltaic microbattery. (paper)

  13. Circuit Simulation for Solar Power Maximum Power Point Tracking with Different Buck-Boost Converter Topologies

    Directory of Open Access Journals (Sweden)

    Jaw-Kuen Shiau

    2014-08-01

    Full Text Available The power converter is one of the essential elements for effective use of renewable power sources. This paper focuses on the development of a circuit simulation model for maximum power point tracking (MPPT evaluation of solar power that involves using different buck-boost power converter topologies; including SEPIC, Zeta, and four-switch type buck-boost DC/DC converters. The circuit simulation model mainly includes three subsystems: a PV model; a buck-boost converter-based MPPT system; and a fuzzy logic MPPT controller. Dynamic analyses of the current-fed buck-boost converter systems are conducted and results are presented in the paper. The maximum power point tracking function is achieved through appropriate control of the power switches of the power converter. A fuzzy logic controller is developed to perform the MPPT function for obtaining maximum power from the PV panel. The MATLAB-based Simulink piecewise linear electric circuit simulation tool is used to verify the complete circuit simulation model.

  14. Chemical Detection using Electrically Open Circuits having no Electrical Connections

    Science.gov (United States)

    Woodward, Stanley E.; Olgesby, Donald M.; Taylor, Bryant D.; Shams, Qamar A.

    2008-01-01

    This paper presents investigations to date on chemical detection using a recently developed method for designing, powering and interrogating sensors as electrically open circuits having no electrical connections. In lieu of having each sensor from a closed circuit with multiple electrically connected components, an electrically conductive geometric pattern that is powered using oscillating magnetic fields and capable of storing an electric field and a magnetic field without the need of a closed circuit or electrical connections is used. When electrically active, the patterns respond with their own magnetic field whose frequency, amplitude and bandwidth can be correlated with the magnitude of the physical quantities being measured. Preliminary experimental results of using two different detection approaches will be presented. In one method, a thin film of a reactant is deposited on the surface of the open-circuit sensor. Exposure to a specific targeted reactant shifts the resonant frequency of the sensor. In the second method, a coating of conductive material is placed on a thin non-conductive plastic sheet that is placed over the surface of the sensor. There is no physical contact between the sensor and the electrically conductive material. When the conductive material is exposed to a targeted reactant, a chemical reaction occurs that renders the material non-conductive. The change in the material s electrical resistance within the magnetic field of the sensor alters the sensor s response bandwidth and amplitude, allowing detection of the reaction without having the reactants in physical contact with the sensor.

  15. Dynamic performance of maximum power point tracking circuits using sinusoidal extremum seeking control for photovoltaic generation

    Science.gov (United States)

    Leyva, R.; Artillan, P.; Cabal, C.; Estibals, B.; Alonso, C.

    2011-04-01

    The article studies the dynamic performance of a family of maximum power point tracking circuits used for photovoltaic generation. It revisits the sinusoidal extremum seeking control (ESC) technique which can be considered as a particular subgroup of the Perturb and Observe algorithms. The sinusoidal ESC technique consists of adding a small sinusoidal disturbance to the input and processing the perturbed output to drive the operating point at its maximum. The output processing involves a synchronous multiplication and a filtering stage. The filter instance determines the dynamic performance of the MPPT based on sinusoidal ESC principle. The approach uses the well-known root-locus method to give insight about damping degree and settlement time of maximum-seeking waveforms. This article shows the transient waveforms in three different filter instances to illustrate the approach. Finally, an experimental prototype corroborates the dynamic analysis.

  16. Effect of recombination on the open-circuit voltage of a silicon solar cell

    Science.gov (United States)

    Von Roos, O.; Landsberg, P. T.

    1985-01-01

    A theoretical study of the influence of band-band Auger, band-trap Auger, and the ordinary Shockley-Read-Hall mechanism for carrier recombination on the open-circuit voltage VOC of a solar cell is presented. Under reasonable assumptions for the magnitude of rate constants and realistic values for trap densities, surface recombination velocities and band-gap narrowing, the maximum VOC for typical back surface field solar cells is found to lie in the range between 0.61 and 0.72 V independent of base width.

  17. Other origins for the fluorescence modulation of single dye molecules in open-circuit and short-circuit devices.

    Science.gov (United States)

    Teguh, Jefri S; Kurniawan, Michael; Wu, Xiangyang; Sum, Tze Chien; Yeow, Edwin K L

    2013-01-07

    Fluorescence intensity modulation of single Atto647N dye molecules in a short-circuit device and a defective device, caused by damaging an open-circuit device, is due to a variation in the excitation light focus as a result of the formation of an alternating electric current.

  18. MAXIMUM AIR SUCTION INTO HORIZONTAL OPEN ENDED CYLINDRICAL LOUVERED PIPE

    Directory of Open Access Journals (Sweden)

    SAMEER RANJAN SAHU

    2017-02-01

    Full Text Available The main approach behind the present numerical investigation is to estimate the mass flow rate of air sucked into a horizontal open-ended louvered pipe from the surrounding atmosphere. The present numerical investigation has been performed by solving the conservation equations for mass, momentum and energy along with two equation based k-ɛ model for a louvered horizontal cylindrical pipe by finite volume method. It has been found from the numerical investigation that mass suction rate of air into the pipe increases with increase in louvered opening area and the number of nozzles used. Keeping other parameters fixed, for a given mass flow rate there exists an optimum protrusion of nozzle for highest mass suction into the pipe. It was also found from the numerical investigation that increasing the pipe diameter the suction mass flow rate of air was increased.

  19. Correlation between the Open-Circuit Voltage and Charge Transfer State Energy in Organic Photovoltaic Cells.

    Science.gov (United States)

    Zou, Yunlong; Holmes, Russell J

    2015-08-26

    In order to further improve the performance of organic photovoltaic cells (OPVs), it is essential to better understand the factors that limit the open-circuit voltage (VOC). Previous work has sought to correlate the value of VOC in donor-acceptor (D-A) OPVs to the interface energy level offset (EDA). In this work, measurements of electroluminescence are used to extract the charge transfer (CT) state energy for multiple small molecule D-A pairings. The CT state as measured from electroluminescence is found to show better correlation to the maximum VOC than EDA. The difference between EDA and the CT state energy is attributed to the Coulombic binding energy of the CT state. This correlation is demonstrated explicitly by inserting an insulating spacer layer between the donor and acceptor materials, reducing the binding energy of the CT state and increasing the measured VOC. These results demonstrate a direct correlation between maximum VOC and CT state energy.

  20. Protection Scheme for Modular Multilevel Converters under Diode Open-Circuit Faults

    DEFF Research Database (Denmark)

    Deng, Fujin; Zhu, Rongwu; Liu, Dong

    2018-01-01

    devices. The diode open-circuit fault in the submodule (SM) is an important issue for the MMC, which would affect the performance of the MMC and disrupt the operation of the MMC. This paper analyzes the impact of diode open-circuit failures in the SMs on the performance of the MMC and proposes...... a protection scheme for the MMC under diode open-circuit faults. The proposed protection scheme not only can effectively eliminate the possible caused high voltage due to the diode open-circuit fault but also can quickly detect the faulty SMs, which effectively avoids the destruction and protects the MMC....... The proposed protection scheme is verified with a downscale MMC prototype in the laboratory. The results confirm the effectiveness of the proposed protection scheme for the MMC under diode open-circuit faults....

  1. Magnetic field effects on the open circuit potential of ferromagnetic electrodes in corroding solutions.

    Science.gov (United States)

    Dass, Amala; Counsil, Joseph A; Gao, Xuerong; Leventis, Nicholas

    2005-06-02

    Magnetic fields shift the open circuit potential (OCP) of ferromagnetic electrodes (Fe, Co, and Ni) in corroding solutions. The OCP changes we observe (a) follow the series Fe>Co>Ni; (b) increase with the magnetic flux density; (c) reach a maximum with disk electrodes approximately 1 mm in diameter; and (d) depend on the orientation of the electrode. We report that when the surface of the electrode is oriented parallel (theta = 90 degrees) or perpendicular (theta = 0 degrees) to the magnetic field, the open circuit potential moves in opposite directions (positive and negative, respectively) with the largest changes occurring when the electrode surface is parallel to the magnetic field. Nonconvective sleeve electrodes produce the same behavior. The overall experimental evidence suggests that the magnetic field changes the OCP by modifying the surface concentrations of the paramagnetic participants in the corrosion process of the ferromagnetic electrode by species in solution; this in turn is accomplished by imposing a field-gradient driven mode of mass transfer upon paramagnetic species in solution (magnetophoresis). Simulations of the magnetic field around the ferromagnetic electrode at the two extreme orientations considered here show that in one case (theta = 90 degrees) field gradients actually repel, while in the other case (theta = 0 degrees) they attract paramagnetic species in the vicinity of the electrode.

  2. Symmetry-Breaking Charge Transfer in a Zinc Chlorodipyrrin Acceptor for High Open Circuit Voltage Organic Photovoltaics

    KAUST Repository

    Bartynski, Andrew N.; Gruber, Mark; Das, Saptaparna; Rangan, Sylvie; Mollinger, Sonya; Trinh, Cong; Bradforth, Stephen E.; Vandewal, Koen; Salleo, Alberto; Bartynski, Robert A.; Bruetting, Wolfgang; Thompson, Mark E.

    2015-01-01

    © 2015 American Chemical Society. Low open-circuit voltages significantly limit the power conversion efficiency of organic photovoltaic devices. Typical strategies to enhance the open-circuit voltage involve tuning the HOMO and LUMO positions

  3. Open circuit voltage-decay behavior in amorphous p-i-n solar due to injection

    Science.gov (United States)

    Smrity, Manu; Dhariwal, S. R.

    2018-05-01

    The paper deals with the basic recombination processes at the dangling bond and the band tail states at various levels of injection, expressed in terms of short-circuit current density and their role in the behavior of amorphous solar cells. As the level of injection increases the fill factor decreases whereas the open circuit voltage increases very slowly, showing a saturation tendency. Calculations have been done for two values of tail state densities and shows that with an increase in tail state densities both, the fill factor and open circuit voltage decreases, results an overall degradation of the solar cell.

  4. Polymer solar cells with enhanced open-circuit voltage and efficiency

    Science.gov (United States)

    Chen, Hsiang-Yu; Hou, Jianhui; Zhang, Shaoqing; Liang, Yongye; Yang, Guanwen; Yang, Yang; Yu, Luping; Wu, Yue; Li, Gang

    2009-11-01

    Following the development of the bulk heterojunction structure, recent years have seen a dramatic improvement in the efficiency of polymer solar cells. Maximizing the open-circuit voltage in a low-bandgap polymer is one of the critical factors towards enabling high-efficiency solar cells. Study of the relation between open-circuit voltage and the energy levels of the donor/acceptor in bulk heterojunction polymer solar cells has stimulated interest in modifying the open-circuit voltage by tuning the energy levels of polymers. Here, we show that the open-circuit voltage of polymer solar cells constructed based on the structure of a low-bandgap polymer, PBDTTT, can be tuned, step by step, using different functional groups, to achieve values as high as 0.76 V. This increased open-circuit voltage combined with a high short-circuit current density results in a polymer solar cell with a power conversion efficiency as high as 6.77%, as certified by the National Renewable Energy Laboratory.

  5. Efficiency of a variable displacement open circuit floating cup pump

    NARCIS (Netherlands)

    Vael, G.E.M.; Achten, P.A.J.; Brink, van den T.L.

    2009-01-01

    The Floating Cup Displacement principle is a relatively new axial piston displacement principle for hydrostatic pumps, motors and transformers. Since its origin in 2001, it has been mainly applied in fixed displacement pump prototypes. At the SICFP’05, a design for a variable displacement open

  6. Spatial charge motion on an uniform density matrix-general equations in opened and closed circuits

    International Nuclear Information System (INIS)

    Aguiar Monsanto, S. de.

    1983-01-01

    The motion of a space charge cloud embedded in a matrix of constant immobile charge density is studied in open as well as in closed circuit. In the first case, open circuit, the solution is almost trivial as compared as the other one in which, after some work, the problem is reduced to an ordinary differential equation. The method of solution is parallel to that employed in the study of monopolar free space charge motion. The voltage and the current produced by a system with no net charge but with unbalanced local charge density were calculated using the general equations derived in the first part of the work. (Author) [pt

  7. Effects of a parallel resistor on electrical characteristics of a piezoelectric transformer in open-circuit transient state.

    Science.gov (United States)

    Chang, Kuo-Tsai

    2007-01-01

    This paper investigates electrical transient characteristics of a Rosen-type piezoelectric transformer (PT), including maximum voltages, time constants, energy losses and average powers, and their improvements immediately after turning OFF. A parallel resistor connected to both input terminals of the PT is needed to improve the transient characteristics. An equivalent circuit for the PT is first given. Then, an open-circuit voltage, involving a direct current (DC) component and an alternating current (AC) component, and its related energy losses are derived from the equivalent circuit with initial conditions. Moreover, an AC power control system, including a DC-to-AC resonant inverter, a control switch and electronic instruments, is constructed to determine the electrical characteristics of the OFF transient state. Furthermore, the effects of the parallel resistor on the transient characteristics at different parallel resistances are measured. The advantages of adding the parallel resistor also are discussed. From the measured results, the DC time constant is greatly decreased from 9 to 0.04 ms by a 10 k(omega) parallel resistance under open output.

  8. A hybrid analytical model for open-circuit field calculation of multilayer interior permanent magnet machines

    Science.gov (United States)

    Zhang, Zhen; Xia, Changliang; Yan, Yan; Geng, Qiang; Shi, Tingna

    2017-08-01

    Due to the complicated rotor structure and nonlinear saturation of rotor bridges, it is difficult to build a fast and accurate analytical field calculation model for multilayer interior permanent magnet (IPM) machines. In this paper, a hybrid analytical model suitable for the open-circuit field calculation of multilayer IPM machines is proposed by coupling the magnetic equivalent circuit (MEC) method and the subdomain technique. In the proposed analytical model, the rotor magnetic field is calculated by the MEC method based on the Kirchhoff's law, while the field in the stator slot, slot opening and air-gap is calculated by subdomain technique based on the Maxwell's equation. To solve the whole field distribution of the multilayer IPM machines, the coupled boundary conditions on the rotor surface are deduced for the coupling of the rotor MEC and the analytical field distribution of the stator slot, slot opening and air-gap. The hybrid analytical model can be used to calculate the open-circuit air-gap field distribution, back electromotive force (EMF) and cogging torque of multilayer IPM machines. Compared with finite element analysis (FEA), it has the advantages of faster modeling, less computation source occupying and shorter time consuming, and meanwhile achieves the approximate accuracy. The analytical model is helpful and applicable for the open-circuit field calculation of multilayer IPM machines with any size and pole/slot number combination.

  9. Electrical impedance tomography system: an open access circuit design

    Directory of Open Access Journals (Sweden)

    Soleimani Manuchehr

    2006-05-01

    Full Text Available Abstract Background This paper reports a simple 2-D system for electrical impedance tomography EIT, which works efficiently and is low cost. The system has been developed in the Sharif University of Technology Tehran-Iran (for the author's MSc Project. Methods The EIT system consists of a PC in which an I/O card is installed with an external current generator, a multiplexer, a power supply and a phantom with an array of electrodes. The measurement system provides 12-bit accuracy and hence, suitable data acquisition software has been prepared accordingly. The synchronous phase detection method has been implemented for voltage measurement. Different methods of image reconstruction have been used with this instrument to generate electrical conductivity images. Results The results of simulation and real measurement of the system are presented. The reconstruction programs were written in MATLAB and the data acquisition software in C++. The system has been tested with both static and dynamic mode in a 2-D domain. Better results have been produced in the dynamic mode of operation, due to the cancellation of errors. Conclusion In the spirit of open access publication the design details of this simple EIT system are made available here.

  10. Demonstration of a High Open-Circuit Voltage GaN Betavoltaic Microbattery

    International Nuclear Information System (INIS)

    Cheng Zai-Jun; San Hai-Sheng; Chen Xu-Yuan; Liu Bo; Feng Zhi-Hong

    2011-01-01

    A high open-circuit voltage betavoltaic microbattery based on a GaN p-i-n diode is demonstrated. Under the irradiation of a 4×4 mm 2 planar solid 63 Ni source with an activity of 2 mCi, the open-circuit voltage V oc of the fabricated single 2×2mm 2 cell reaches as high as 1.62 V, the short-circuit current density J sc is measured to be 16nA/cm 2 . The microbattery has a fill factor of 55%, and the energy conversion efficiency of beta radiation into electricity reaches to 1.13%. The results suggest that GaN is a highly promising potential candidate for long-life betavoltaic microbatteries used as power supplies for microelectromechanical system devices. (cross-disciplinary physics and related areas of science and technology)

  11. Influence of a MoOx interlayer on the open-circuit voltage in organic photovoltaic cells

    Science.gov (United States)

    Zou, Yunlong; Holmes, Russell J.

    2013-07-01

    Metal-oxides have been used as interlayers at the anode-organic interface in organic photovoltaic cells (OPVs) to increase the open-circuit voltage (VOC). We examine the role of MoOx in determining the maximum VOC in a planar heterojunction OPV and find that the interlayer strongly affects the temperature dependence of VOC. Boron subphthalocyanine chloride (SubPc)-C60 OPVs that contain no interlayer show a maximum VOC of 1.2 V at low temperature, while those with MoOx show no saturation, reaching VOC > 1.4 V. We propose that the MoOx-SubPc interface forms a Schottky junction that provides an additional contribution to VOC at low temperature.

  12. Resonator reset in circuit QED by optimal control for large open quantum systems

    Science.gov (United States)

    Boutin, Samuel; Andersen, Christian Kraglund; Venkatraman, Jayameenakshi; Ferris, Andrew J.; Blais, Alexandre

    2017-10-01

    We study an implementation of the open GRAPE (gradient ascent pulse engineering) algorithm well suited for large open quantum systems. While typical implementations of optimal control algorithms for open quantum systems rely on explicit matrix exponential calculations, our implementation avoids these operations, leading to a polynomial speedup of the open GRAPE algorithm in cases of interest. This speedup, as well as the reduced memory requirements of our implementation, are illustrated by comparison to a standard implementation of open GRAPE. As a practical example, we apply this open-system optimization method to active reset of a readout resonator in circuit QED. In this problem, the shape of a microwave pulse is optimized such as to empty the cavity from measurement photons as fast as possible. Using our open GRAPE implementation, we obtain pulse shapes, leading to a reset time over 4 times faster than passive reset.

  13. Solar cell degradation under open circuit condition in out-doors-in desert region

    Directory of Open Access Journals (Sweden)

    M. Boussaid

    Full Text Available The reliability of solar cells is an important parameter in the design of photovoltaic systems and particularly for cost estimation. Solar cell degradation is the result of various operating conditions; temperature is one of most important factors. Installed PV modules in desert regions are subjected to various temperature changes with significant gradient leading to accelerated degradation. In the present work, we demonstrate the influence of open-circuit condition on the degradation of PV modules. The experiment is carried out in the desert region of ADRAR (southern Algeria using two modules IJISEL of single-crystal silicon. A continuous monitoring allows analysis of both performances of modules for duration of 330 days. The module in open-circuit condition reaches higher temperature means than the module in charging condition; therefore, it undergoes a higher degradation. By simulation, we found that the life of a PV module (whose power output is close to 50% in a condition of an open-circuit in the desert region could be reduced to 4 years, and that has a significant impact on economy. Keywords: WEIBULL, Photovoltaic, Degradation, Open-circuit, Single-crystal, Silicon

  14. Elucidating the interplay between dark current coupling and open circuit voltage in organic photovoltaics

    KAUST Repository

    Erwin, Patrick; Thompson, Mark E.

    2011-01-01

    made with the structure indium tin oxide/copper phthalocyanine (200 Å)/PDI (200 Å)/bathocuproine (100 Å)/aluminum (1000 Å). We found that PDIs with larger substituents produced higher open circuit voltages (VOC's) despite the donor acceptor interface

  15. Battery open-circuit voltage estimation by a method of statistical analysis

    NARCIS (Netherlands)

    Snihir, Iryna; Rey, William; Verbitskiy, Evgeny; Belfadhel-Ayeb, Afifa; Notten, Peter H.L.

    2006-01-01

    The basic task of a battery management system (BMS) is the optimal utilization of the stored energy and minimization of degradation effects. It is critical for a BMS that the state-of-charge (SoC) be accurately determined. Open-circuit voltage (OCV) is directly related to the state-of-charge of the

  16. An open circuit balance respirometer for bioenergetic studies of fish growth

    NARCIS (Netherlands)

    Hogendoorn, H.; Korlaar, van F.; Bosch, H.

    1981-01-01

    A description is given of an open circuit balance respirometer for bioenergetic studies of fish growth using indirect calorimetry. The installation was designed to enable the determination of gas and matter balances of fish, including air breathing species, during prolonged experimental periods.

  17. A hybrid analytical model for open-circuit field calculation of multilayer interior permanent magnet machines

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhen [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Xia, Changliang [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Tianjin Engineering Center of Electric Machine System Design and Control, Tianjin 300387 (China); Yan, Yan, E-mail: yanyan@tju.edu.cn [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Geng, Qiang [Tianjin Engineering Center of Electric Machine System Design and Control, Tianjin 300387 (China); Shi, Tingna [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China)

    2017-08-01

    Highlights: • A hybrid analytical model is developed for field calculation of multilayer IPM machines. • The rotor magnetic field is calculated by the magnetic equivalent circuit method. • The field in the stator and air-gap is calculated by subdomain technique. • The magnetic scalar potential on rotor surface is modeled as trapezoidal distribution. - Abstract: Due to the complicated rotor structure and nonlinear saturation of rotor bridges, it is difficult to build a fast and accurate analytical field calculation model for multilayer interior permanent magnet (IPM) machines. In this paper, a hybrid analytical model suitable for the open-circuit field calculation of multilayer IPM machines is proposed by coupling the magnetic equivalent circuit (MEC) method and the subdomain technique. In the proposed analytical model, the rotor magnetic field is calculated by the MEC method based on the Kirchhoff’s law, while the field in the stator slot, slot opening and air-gap is calculated by subdomain technique based on the Maxwell’s equation. To solve the whole field distribution of the multilayer IPM machines, the coupled boundary conditions on the rotor surface are deduced for the coupling of the rotor MEC and the analytical field distribution of the stator slot, slot opening and air-gap. The hybrid analytical model can be used to calculate the open-circuit air-gap field distribution, back electromotive force (EMF) and cogging torque of multilayer IPM machines. Compared with finite element analysis (FEA), it has the advantages of faster modeling, less computation source occupying and shorter time consuming, and meanwhile achieves the approximate accuracy. The analytical model is helpful and applicable for the open-circuit field calculation of multilayer IPM machines with any size and pole/slot number combination.

  18. Simultaneous improvement in short circuit current, open circuit voltage, and fill factor of polymer solar cells through ternary strategy.

    Science.gov (United States)

    An, Qiaoshi; Zhang, Fujun; Li, Lingliang; Wang, Jian; Sun, Qianqian; Zhang, Jian; Tang, Weihua; Deng, Zhenbo

    2015-02-18

    We present a smart strategy to simultaneously increase the short circuit current (Jsc), the open circuit voltage (Voc), and the fill factor (FF) of polymer solar cells (PSCs). A two-dimensional conjugated small molecule photovoltaic material (SMPV1), as the second electron donor, was doped into the blend system of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C71-butyric acid methyl (PC71BM) to form ternary PSCs. The ternary PSCs with 5 wt % SMPV1 doping ratio in donors achieve 4.06% champion power conversion efficiency (PCE), corresponding to about 21.2% enhancement compared with the 3.35% PCE of P3HT:PC71BM-based PSCs. The underlying mechanism on performance improvement of ternary PSCs can be summarized as (i) harvesting more photons in the longer wavelength region to increase Jsc; (ii) obtaining the lower mixed highest occupied molecular orbital (HOMO) energy level by incorporating SMPV1 to increase Voc; (iii) forming the better charge carrier transport channels through the cascade energy level structure and optimizing phase separation of donor/acceptor materials to increase Jsc and FF.

  19. THE RISE AND FALL OF OPEN SOLAR FLUX DURING THE CURRENT GRAND SOLAR MAXIMUM

    International Nuclear Information System (INIS)

    Lockwood, M.; Rouillard, A. P.; Finch, I. D.

    2009-01-01

    We use geomagnetic activity data to study the rise and fall over the past century of the solar wind flow speed V SW , the interplanetary magnetic field strength B, and the open solar flux F S . Our estimates include allowance for the kinematic effect of longitudinal structure in the solar wind flow speed. As well as solar cycle variations, all three parameters show a long-term rise during the first half of the 20th century followed by peaks around 1955 and 1986 and then a recent decline. Cosmogenic isotope data reveal that this constitutes a grand maximum of solar activity which began in 1920, using the definition that such grand maxima are when 25-year averages of the heliospheric modulation potential exceeds 600 MV. Extrapolating the linear declines seen in all three parameters since 1985, yields predictions that the grand maximum will end in the years 2013, 2014, or 2027 using V SW , F S , or B, respectively. These estimates are consistent with predictions based on the probability distribution of the durations of past grand solar maxima seen in cosmogenic isotope data. The data contradict any suggestions of a floor to the open solar flux: we show that the solar minimum open solar flux, kinematically corrected to allow for the excess flux effect, has halved over the past two solar cycles.

  20. Energy-level alignment and open-circuit voltage at graphene/polymer interfaces: theory and experiment

    Science.gov (United States)

    Noori, Keian; Konios, Dimitrios; Stylianakis, Minas M.; Kymakis, Emmanuel; Giustino, Feliciano

    2016-03-01

    Functionalized graphene promises to become a key component of novel solar cell architectures, owing to its versatile ability to act either as transparent conductor, electron acceptor, or buffer layer. In spite of this promise, the solar energy conversion efficiency of graphene-based devices falls short of the performance of competing solution-processable photovoltaic technologies. Here we address the question of the maximum achievable open-circuit voltage of all-organic graphene: polymer solar cells using a combined theoretical/experimental approach, going from the atomic scale level to the device level. Our calculations on very large atomistic models of the graphene/polymer interface indicate that the ideal open-circuit voltage approaches one volt, and that epoxide functional groups can have a dramatic effect on the photovoltage. Our predictions are confirmed by direct measurements on complete devices where we control the concentration of functional groups via chemical reduction. Our findings indicate that the selective removal of epoxide groups and the use of ultradisperse polymers are key to achieving graphene solar cells with improved energy conversion efficiency.

  1. Numerical simulation for arc-plasma dynamics during contact opening process in electrical circuit-breakers

    International Nuclear Information System (INIS)

    Gupta, D N; Srinivas, D; Patil, G N; Kale, S S; Potnis, S B

    2010-01-01

    The high-energy, high-current thermal plasma that develops between electric contacts in a gas circuit-breaker during circuit interruption is an important phenomenon in the power transmission industry. The high temperature and pressure arc dissipates the tremendous amount of energy generated by the fault current. Simultaneously, this energy has to be transferred away from the contacts to build the dielectric strength level of the circuit-breaker. In order to interrupt the current, the arc must be weakened and finally extinguished. We model these phenomena by using a computer software code based on the solution of the unsteady Euler equations of gas dynamics. We consider the equations of fluid flows. These equations are solved numerically in complex circuit breaker geometries using a finite-volume method. The domain is initially filled with SF 6 gas. We begin our simulations from cold mode, where the fault current is not present (hence no arc). An axis-symmetric geometry of a 145 kV gas circuit-breaker is considered to study the pressure, density, and temperature profile during contact opening process.

  2. Driving CZTS to the SQ Limit: Solving the Open Circuit Voltage Problem

    Energy Technology Data Exchange (ETDEWEB)

    Haight, Richard A. [IBM Research, Yorktown, NY (United States). Thomas J. Watson Research Center; McCandless, Brian E. [Univ. of Delaware, Newark, DE (United States); Kummel, Andrew C. [Univ. of California, San Diego, CA (United States); Gordon, Roy G. [Harvard Univ., Cambridge, MA (United States)

    2016-12-15

    A key objective of this 3 year research effort was to reduce the open circuit voltage (Voc) deficit, defined as the difference between the absorber band gap and the measured Voc to below 475mV from values at the beginning of this work of 630-730mV. To achieve this reduction, along with the attendant goals of higher Voc and efficiency, detailed studies into the fundamental understanding of existing limitations were undertaken.

  3. The open-circuit voltage in microcrystalline silicon solar cells of different degrees of crystallinity

    International Nuclear Information System (INIS)

    Nath, Madhumita; Roca i Cabarrocas, P.; Johnson, E.V.; Abramov, A.; Chatterjee, P.

    2008-01-01

    We have used a detailed electrical-optical computer model (ASDMP) in conjunction with the experimental characterization of microcrystalline silicon thin-film solar cells of different degrees of crystallinity (but having identical P- and N-layers) to understand the observed decrease of the open-circuit voltage with increasing crystalline fraction. In order to model all aspects of the experimental current density-voltage and quantum efficiency characteristics of cells having low (∼ 75%) and high (over 90%) crystalline fraction, we had to assume both a higher mobility gap defect density and a lower band gap for the more crystallized material. The former fact is widely known to bring down the open-circuit voltage. Our calculations also reveal that the proximity of the quasi-Fermi levels to the energy bands in the cell based on highly crystallized (and assumed to have a lower band gap) microcrystalline silicon results in higher free and trapped carrier densities in this device. The trapped hole population is particularly high at and close to the P/I interface on account of the higher inherent defect density in this region and the fact that the hole quasi-Fermi level is close to the valence band edge here. This fact results in a strong interface field, a collapse of the field in the volume, and hence a lower open-circuit voltage. Thus a combination of higher mobility gap defects and a lower band gap is probably the reason for the lower open-circuit voltage in cells based on highly crystallized microcrystalline silicon

  4. The effect of a defective BSF layer on solar cell open circuit voltage. [Back Surface Field

    Science.gov (United States)

    Weizer, V. G.

    1985-01-01

    A straightforward analysis of special limiting cases has permitted the determination of the range of possible open circuit voltage losses due to a defective BSF (back surface field) layer. An important result of the analysis is the finding that it is possible to have a fully effective BSF region, regardless of the spatial distribution of the defective areas, as long as the total defective area is reduced below certain limits. Distributed defects were found to be much more harmful than lumped defects.

  5. Wireless Sensing System Using Open-circuit, Electrically-conductive Spiral-trace Sensor

    Science.gov (United States)

    Woodard, Stanley E. (Inventor); Taylor, Bryant D. (Inventor)

    2013-01-01

    A wireless sensing system includes a sensor made from an electrical conductor shaped to form an open-circuit, electrically-conductive spiral trace having inductance and capacitance. In the presence of a time-varying magnetic field, the sensor resonates to generate a harmonic response having a frequency, amplitude and bandwidth. A magnetic field response recorder wirelessly transmits the time-varying magnetic field to the sensor and wirelessly detects the sensor's response frequency, amplitude and bandwidth.

  6. Thermocleavable Materials for Polymer Solar Cells with High Open Circuit Voltage-A Comparative Study

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Gevorgyan, Suren; Jørgensen, Mikkel

    2009-01-01

    The search for polymer solar cells giving a high open circuit voltage was conducted through a comparative study of four types of bulk-heterojunction solar cells employing different photoactive layers. As electron donors the thermo-cleavable polymer poly-(3-(2-methylhexyloxycarbonyl)dithiophene) (P3......MHOCT) and unsubstituted polythiophene (PT) were used, the latter of which results from thermo cleaving the former at 310 °C. As reference, P3HT solar cells were built in parallel. As electron acceptors, either PCBM or bis-[60]PCBM were used. In excess of 300 solar cells were produced under as identical...... conditions as possible, varying only the material combination of the photo active layer. It was observed that on replacing PCBM with bis[60]PCBM, the open circuit voltage on average increased by 100 mV for P3MHOCT and 200 mV for PT solar cells. Open circuit voltages approaching 1 V were observed for the PT:bis...

  7. Enhanced Open-Circuit Voltage in Visible Quantum Dot Photovoltaics by Engineering of Carrier-Collecting Electrodes

    KAUST Repository

    Wang, Xihua

    2011-10-26

    Colloidal quantum dots (CQDs) enable multijunction solar cells using a single material programmed using the quantum size effect. Here we report the systematic engineering of 1.6 eV PbS CQD solar cells, optimal as the front cell responsible for visible-wavelength harvesting in tandem photovoltaics. We rationally optimize each of the device\\'s collecting electrodes-the heterointerface with electron-accepting TiO2 and the deep-work-function hole-collecting MoO3 for ohmic contact-for maximum efficiency. We report an open-circuit voltage of 0.70 V, the highest observed in a colloidal quantum dot solar cell operating at room temperature. We report an AM1.5 solar power conversion efficiency of 3.5%, the highest observed in >1.5 eV bandgap CQD PV device. © 2011 American Chemical Society.

  8. Open external circuit for microbial fuel cell sensor to monitor the nitrate in aquatic environment.

    Science.gov (United States)

    Wang, Donglin; Liang, Peng; Jiang, Yong; Liu, Panpan; Miao, Bo; Hao, Wen; Huang, Xia

    2018-07-15

    This study employed an open external circuit, rather than a closed circuit applied in previous studies, to operate an microbial fuel cell (MFC) sensor for real-time nitrate monitoring, and achieved surprisingly greater sensitivity (4.42 ± 0.3-6.66 ± 0.4 mV/(mg/L)) when the nitrate was at a concentration of 10-40 mg/L, compared to that of the MFC sensor with a closed circuit (0.8 ± 0.05-1.6 ± 0.1 mV/(mg/L)). The MFC sensor operated in open circuit (O-MFC sensor) delivered much more stable performance than that operated in closed circuit (C-MFC sensor) when affected by organic matter (NaAc). The sensitivity of O-MFC sensor was twice that of C-MFC sensor at a low background concentration of organic matter. When organic matter reached a high concentration, the sensitivity of O-MFC sensor remained at an acceptable level, while that of C-MFC sensor dropped to almost zero. Challenged by a combined shock of organic matter and nitrate, O-MFC sensor delivered evident electrical signals for nitrate warning, while C-MFC failed. Another novel feature of this study lies in a new mathematical model to examine the bioanode process of nitrate monitoring. It revealed that lower capacitance of the bioanode in O-MFC was the major contributor to the improved sensitivity of the device. Copyright © 2018 Elsevier B.V. All rights reserved.

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

    KAUST Repository

    Ko, Sangwon

    2012-03-21

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

  10. Controlled conjugated backbone twisting for an increased open-circuit voltage while having a high short-circuit current in poly(hexylthiophene) derivatives.

    Science.gov (United States)

    Ko, Sangwon; Hoke, Eric T; Pandey, Laxman; Hong, Sanghyun; Mondal, Rajib; Risko, Chad; Yi, Yuanping; Noriega, Rodrigo; McGehee, Michael D; Brédas, Jean-Luc; Salleo, Alberto; Bao, Zhenan

    2012-03-21

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

  11. Detection Method for Soft Internal Short Circuit in Lithium-Ion Battery Pack by Extracting Open Circuit Voltage of Faulted Cell

    Directory of Open Access Journals (Sweden)

    Minhwan Seo

    2018-06-01

    Full Text Available Early detection of internal short circuit which is main cause of thermal runaway in a lithium-ion battery is necessary to ensure battery safety for users. As a promising fault index, internal short circuit resistance can directly represent degree of the fault because it describes self-discharge phenomenon caused by the internal short circuit clearly. However, when voltages of individual cells in a lithium-ion battery pack are not provided, the effect of internal short circuit in the battery pack is not readily observed in whole terminal voltage of the pack, leading to difficulty in estimating accurate internal short circuit resistance. In this paper, estimating the resistance with the whole terminal voltages and the load currents of the pack, a detection method for the soft internal short circuit in the pack is proposed. Open circuit voltage of a faulted cell in the pack is extracted to reflect the self-discharge phenomenon obviously; this process yields accurate estimates of the resistance. The proposed method is verified with various soft short conditions in both simulations and experiments. The error of estimated resistance does not exceed 31.2% in the experiment, thereby enabling the battery management system to detect the internal short circuit early.

  12. Corrections for hysteresis curves for rare earth magnet materials measured by open magnetic circuit methods

    International Nuclear Information System (INIS)

    Nakagawa, Yasuaki

    1996-01-01

    The methods for testing permanent magnets stipulated in the usual industrial standards are so-called closed magnetic circuit methods which employ a loop tracer using an iron-core electromagnet. If the coercivity exceeds the highest magnetic field generated by the electromagnet, full hysteresis curves cannot be obtained. In the present work, magnetic fields up to 15 T were generated by a high-power water-cooled magnet, and the magnetization was measured by an induction method with an open magnetic circuit, in which the effect of a demagnetizing field should be taken into account. Various rare earth magnets materials such as sintered or bonded Sm-Co and Nd-Fe-B were provided by a number of manufacturers. Hysteresis curves for cylindrical samples with 10 nm in diameter and 2 mm, 3.5 mm, 5 mm, 14 mm or 28 mm in length were measured. Correction for the demagnetizing field is rather difficult because of its non-uniformity. Roughly speaking, a mean demagnetizing factor for soft magnetic materials can be used for the correction, although the application of this factor to hard magnetic material is hardly justified. Thus the dimensions of the sample should be specified when the data obtained by the open magnetic circuit method are used as industrial standards. (author)

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

    Science.gov (United States)

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

    2015-11-07

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

  14. Parallelization of maximum likelihood fits with OpenMP and CUDA

    CERN Document Server

    Jarp, S; Leduc, J; Nowak, A; Pantaleo, F

    2011-01-01

    Data analyses based on maximum likelihood fits are commonly used in the high energy physics community for fitting statistical models to data samples. This technique requires the numerical minimization of the negative log-likelihood function. MINUIT is the most common package used for this purpose in the high energy physics community. The main algorithm in this package, MIGRAD, searches the minimum by using the gradient information. The procedure requires several evaluations of the function, depending on the number of free parameters and their initial values. The whole procedure can be very CPU-time consuming in case of complex functions, with several free parameters, many independent variables and large data samples. Therefore, it becomes particularly important to speed-up the evaluation of the negative log-likelihood function. In this paper we present an algorithm and its implementation which benefits from data vectorization and parallelization (based on OpenMP) and which was also ported to Graphics Processi...

  15. Closed and open breathing circuit function in healthy volunteers during exercise at Mount Everest base camp (5300 m)

    NARCIS (Netherlands)

    McMorrow, R. C. N.; Windsor, J. S.; Hart, N. D.; Richards, P.; Rodway, G. W.; Ahuja, V. Y.; O'Dwyer, M. J.; Mythen, M. G.; Grocott, M. P. W.; Ahuja, V.; Aref-Adib, G.; Burnham, R.; Chisholm, A.; Clarke, K.; Coates, D.; Coates, M.; Cook, D.; Cox, M.; Dhillon, S.; Dougall, C.; Doyle, P.; Duncan, P.; Edsell, M.; Edwards, L.; Evans, L.; Gardiner, P.; Grocott, M.; Gunning, P.; Hart, N.; Harrington, J.; Harvey, J.; Holloway, C.; Howard, D.; Hurlbut, D.; Imray, C.; Ince, C.; Jonas, M.; van der Kaaij, J.; Khosravi, M.; Kolfschoten, N.; Levett, D.; Luery, H.; Luks, A.; Martin, D.; McMorrow, R.; Meale, P.; Mitchell, K.; Montgomery, H.; Morgan, G.; Morgan, J.

    2012-01-01

    We present a randomised, controlled, crossover trial of the Caudwell Xtreme Everest (CXE) closed circuit breathing system vs an open circuit and ambient air control in six healthy, hypoxic volunteers at rest and exercise at Everest Base Camp, at 5300 m. Compared with control, arterial oxygen

  16. Elucidating the interplay between dark current coupling and open circuit voltage in organic photovoltaics

    KAUST Repository

    Erwin, Patrick

    2011-01-01

    A short series of alkyl substituted perylenediimides (PDIs) with varying steric bulk are used to demonstrate the relationship between molecular structure, materials properties, and performance characteristics in organic photovoltaics. Devices were made with the structure indium tin oxide/copper phthalocyanine (200 Å)/PDI (200 Å)/bathocuproine (100 Å)/aluminum (1000 Å). We found that PDIs with larger substituents produced higher open circuit voltages (VOC\\'s) despite the donor acceptor interface gap (Δ EDA) remaining unchanged. Additionally, series resistance was increased simultaneously with VOC the effect of reducing short circuit current, making the addition of steric bulk a tradeoff that needs to be balanced to optimize power conversion efficiency. © 2011 American Institute of Physics.

  17. Internal Short-Circuiting Phenomena In An Open-Cycle MHD Generator

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Y.; Ishibashi, E. [Hitachi Research Laboratory, Hitachi-shi, Ibaraki-ken (Japan); Kasahara, T.; Kazawa, Y. [Hitachi Works, Hitachi Ltd., Hitachi-shi, Ibaraki-ken (Japan)

    1968-11-15

    The influence of internal electrical leakage due to circulating currents flowing through velocity boundary layers and due to metallic elements in insulating walls (peg walls) is experimentally investigated. For this purpose a combustion-driven MHD generator is utilized. The active part of the generator test section is 60 cm in length with a constant cross-section of 3 x 12 cm{sup 2}. At typical operating conditions about 70 g/s of diesel light oil is burned with oxygen-enriched air, resulting in a thermal input of 3 MW, a fluid velocity of 500 to 700 m/s and a gas temperature of 2700 to 2900 Degree-Sign K at the channel inlet. KOH is used as the seed material. The magnetic field can be raised up to 1.95 Teslas. In the range of lower magnetic fields (B < 0.8T) it is shown that an observed open-circuit voltage agrees well with the theoretical value OBh which is defined in a one-dimensional MHD model. In other words, the circulating currents scarcely affect the open-circuit voltage. The theoretical basis for this fact is obtained by the use of a simple model. Experimental results obtained in several runs using three sets of insulating walls show that thermal boundary layers at water-cooled metals are more conductive than expected and that the open- circuit voltage decreases because of leakage currents flowing through metal pegs, when the internal resistance of the generator is relatively large. Also, it is shown that an alumina coating is effective in reducing the leakage currents. (author)

  18. Closed and open breathing circuit function in healthy volunteers during exercise at Mount Everest base camp (5300 m).

    LENUS (Irish Health Repository)

    McMorrow, R C N

    2012-08-01

    We present a randomised, controlled, crossover trial of the Caudwell Xtreme Everest (CXE) closed circuit breathing system vs an open circuit and ambient air control in six healthy, hypoxic volunteers at rest and exercise at Everest Base Camp, at 5300 m. Compared with control, arterial oxygen saturations were improved at rest with both circuits. There was no difference in the magnitude of this improvement as both circuits restored median (IQR [range]) saturation from 75%, (69.5-78.9 [68-80]%) to > 99.8% (p = 0.028). During exercise, the CXE closed circuit improved median (IQR [range]) saturation from a baseline of 70.8% (63.8-74.5 [57-76]%) to 98.8% (96.5-100 [95-100]%) vs the open circuit improvement to 87.5%, (84.1-88.6 [82-89]%; p = 0.028). These data demonstrate the inverse relationship between supply and demand with open circuits and suggest that ambulatory closed circuits may offer twin advantages of supplying higher inspired oxygen concentrations and\\/or economy of gas use for exercising hypoxic adults.

  19. Ultra high open circuit voltage (>1 V) of poly-3-hexylthiophene based organic solar cells with concentrated light

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Madsen, Morten Vesterager; Krebs, Frederik C

    2013-01-01

    to 2000 solar intensities of these photoactive blends. Comparison of solar cells based on five different fullerene derivatives shows that at both short circuit and open circuit conditions, recombination remains unchanged up to 50 suns. Determination of Voc at 2000 suns demonstrated that the same......One approach to increasing polymer solar cell efficiency is to blend poly-(3-hexyl-thiophene) with poorly electron accepting fullerene derivatives to obtain higher open circuit voltage (Voc). In this letter concentrated light is used to study the electrical properties of cell operation at up...

  20. Lifetime measurements by open circuit voltage decay in GaAs and InP diodes

    International Nuclear Information System (INIS)

    Bhimnathwala, H.G.; Tyagi, S.D.; Bothra, S.; Ghandhi, S.K.; Borrego, J.M.

    1990-01-01

    Minority carrier lifetimes in the base of solar cells made in GaAs and InP are measured by open circuit voltage decay method. This paper describes the measurement technique and the conditions under which the minority carrier lifetimes can be measured. Minority carrier lifetimes ranging from 1.6 to 34 ns in InP of different doping concentrations are measured. A minority carrier lifetime of 6 ns was measured in n-type GaAs which agrees well with the lifetime of 5.7 ns measured by transient microwave reflection

  1. Detection of Single Pt Nanoparticle Collisions by Open-Circuit Potential Changes at Ag Ultramicroelectrode

    International Nuclear Information System (INIS)

    Mun, Seon Kyu; Shin, Changhwan; Kwon, Seong Jung

    2016-01-01

    Single platinum (Pt) nanoparticle (NP) collisions were investigated with open-circuit potential (OCP) using a silver (Ag) ultramicroelectrode (UME). The Ag UME showed higher sensitivity to single Pt NP detection by the OCP method than gold (Au) UME. The detection of ⁓2 nm radius Pt NP collisions was carried out successfully using Ag UME. The magnitude of the potential step and collision frequency for the single Pt NP collision on Ag UME was investigated and compared with those of the previous work done on Au UME.

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    , in the form of an electric control signal, under varying working conditions, when having access to engine speed and actual pump pressure. The paper presents a model of both the pump and the control module, along with design considerations on which linear controllers are developed for a worst point......This paper deals with the problem of designing an electric control module for a Sauer-Danfoss Series 45 H-frame open circuit axial piston pump. The purpose of the electric control module is to replace the existing hydro-mechanical (LS) regulator, and enable the pump to follow a reference pressure...

  3. An Adaptive Estimation Scheme for Open-Circuit Voltage of Power Lithium-Ion Battery

    Directory of Open Access Journals (Sweden)

    Yun Zhang

    2013-01-01

    Full Text Available Open-circuit voltage (OCV is one of the most important parameters in determining state of charge (SoC of power battery. The direct measurement of it is costly and time consuming. This paper describes an adaptive scheme that can be used to derive OCV of the power battery. The scheme only uses the measurable input (terminal current and the measurable output (terminal voltage signals of the battery system and is simple enough to enable online implement. Firstly an equivalent circuit model is employed to describe the polarization characteristic and the dynamic behavior of the lithium-ion battery; the state-space representation of the electrical performance for the battery is obtained based on the equivalent circuit model. Then the implementation procedure of the adaptive scheme is given; also the asymptotic convergence of the observer error and the boundedness of all the parameter estimates are proven. Finally, experiments are carried out, and the effectiveness of the adaptive estimation scheme is validated by the experimental results.

  4. Characterization of bacterial and archaeal communities in air-cathode microbial fuel cells, open circuit and sealed-off reactors

    KAUST Repository

    Chehab, Noura A.

    2013-06-18

    A large percentage of organic fuel consumed in a microbial fuel cell (MFC) is lost as a result of oxygen transfer through the cathode. In order to understand how this oxygen transfer affects the microbial community structure, reactors were operated in duplicate using three configurations: closed circuit (CC; with current generation), open circuit (OC; no current generation), and sealed off cathodes (SO; no current, with a solid plate placed across the cathode). Most (98 %) of the chemical oxygen demand (COD) was removed during power production in the CC reactor (maximum of 640 ± 10 mW/m 2), with a low percent of substrate converted to current (coulombic efficiency of 26.5 ± 2.1 %). Sealing the cathode reduced COD removal to 7 %, but with an open cathode, there was nearly as much COD removal by the OC reactor (94.5 %) as the CC reactor. Oxygen transfer into the reactor substantially affected the composition of the microbial communities. Based on analysis of the biofilms using 16S rRNA gene pyrosequencing, microbes most similar to Geobacter were predominant on the anodes in the CC MFC (72 % of sequences), but the most abundant bacteria were Azoarcus (42 to 47 %) in the OC reactor, and Dechloromonas (17 %) in the SO reactor. Hydrogenotrophic methanogens were most predominant, with sequences most similar to Methanobacterium in the CC and SO reactor, and Methanocorpusculum in the OC reactors. These results show that oxygen leakage through the cathode substantially alters the bacterial anode communities, and that hydrogenotrophic methanogens predominate despite high concentrations of acetate. The predominant methanogens in the CC reactor most closely resembled those in the SO reactor, demonstrating that oxygen leakage alters methanogenic as well as general bacterial communities. © 2013 Springer-Verlag Berlin Heidelberg.

  5. Characterization of bacterial and archaeal communities in air-cathode microbial fuel cells, open circuit and sealed-off reactors

    KAUST Repository

    Chehab, Noura A.; Li, Dong; Amy, Gary L.; Logan, Bruce E.; Saikaly, Pascal

    2013-01-01

    A large percentage of organic fuel consumed in a microbial fuel cell (MFC) is lost as a result of oxygen transfer through the cathode. In order to understand how this oxygen transfer affects the microbial community structure, reactors were operated in duplicate using three configurations: closed circuit (CC; with current generation), open circuit (OC; no current generation), and sealed off cathodes (SO; no current, with a solid plate placed across the cathode). Most (98 %) of the chemical oxygen demand (COD) was removed during power production in the CC reactor (maximum of 640 ± 10 mW/m 2), with a low percent of substrate converted to current (coulombic efficiency of 26.5 ± 2.1 %). Sealing the cathode reduced COD removal to 7 %, but with an open cathode, there was nearly as much COD removal by the OC reactor (94.5 %) as the CC reactor. Oxygen transfer into the reactor substantially affected the composition of the microbial communities. Based on analysis of the biofilms using 16S rRNA gene pyrosequencing, microbes most similar to Geobacter were predominant on the anodes in the CC MFC (72 % of sequences), but the most abundant bacteria were Azoarcus (42 to 47 %) in the OC reactor, and Dechloromonas (17 %) in the SO reactor. Hydrogenotrophic methanogens were most predominant, with sequences most similar to Methanobacterium in the CC and SO reactor, and Methanocorpusculum in the OC reactors. These results show that oxygen leakage through the cathode substantially alters the bacterial anode communities, and that hydrogenotrophic methanogens predominate despite high concentrations of acetate. The predominant methanogens in the CC reactor most closely resembled those in the SO reactor, demonstrating that oxygen leakage alters methanogenic as well as general bacterial communities. © 2013 Springer-Verlag Berlin Heidelberg.

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

    Directory of Open Access Journals (Sweden)

    Gheorghe BALUTA

    2004-12-01

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

  7. Comparison of biocides for disinfection treatment of open recirculating cooling circuits

    International Nuclear Information System (INIS)

    Soreau, Sylvie; Prisset, Frederic; Carvajal, Nathalie

    2012-09-01

    Open recirculating cooling circuits of nuclear power plants are likely to face pathogenic proliferations like Legionella and amoebae (Naegleria fowleri). To reduce such risks, biocide treatments are usually implemented. However, the selection of a treatment is never easy due to the large size of the cooling circuits. Indeed, the range of treatment options is limited due to potential health or environmental impacts of chemicals in case of chemical treatments or because of the technical difficulties to implement treatment units appropriate to the size of the cooling circuits in case of physical treatments. In the aim of finding the best compromise between efficacy, nature and quantity of chemical releases and industrial feasibility, several biocide treatments were compared at lab and pilot scale using semi-industrial pilot plants simulating recirculating cooling circuit of a nuclear power plant. These pilots were fed with river water or pre-treated water (lime softening or clari-flocculation). They were equipped with materials and surfaces representative of those found on a full-scale plant. These pilots operated at summer temperatures favoring microbial growth. Three industrial biocides were compared: chlorine, monochloramine and chlorine dioxide. The results indicate that the transit in the cooling system strongly affects the consumption of biocides and therefore their efficacy, the quantity of biocide needed and chemical releases so that the ranking of treatments defined on the basis of laboratory tests can be strongly modified. The results show different areas of consumption along the process line depending on biocides and highlight the significant role of the cooling tower. The behavior of biocides in the different compartments of the circuit (cooling tower, condenser, basins) is described and the consequences on pathogenic micro-organisms removal in bio-films and on chemical releases are considered as function of the studied biocide. Moreover, the influence of

  8. Open- and Short-Circuit Fault Identification for a Boost dc/dc Converter in PV MPPT Systems

    Directory of Open Access Journals (Sweden)

    Diego R. Espinoza Trejo

    2018-03-01

    Full Text Available This paper proposes a fault identification system for short and open-circuit switch faults (SOCSF for a dc/dc converter acting as a Maximum Power Point Tracker (MPPT in Photovoltaic (PV systems. A closed-loop operation is assumed for the boost dc/dc converter. A linearizing control plus a Proportional-Derivative (PD controller is suggested for PV voltage regulation at the maximum power point (MPP. In this study, the SOCSF are modeled by using an additive fault representation and the fault identification (FI system is synthesized departing from a Luenberger observer. Hence, an FI signal is obtained, which is insensitive to irradiance and load current changes, but affected by the SOCSF. For FI purposes, only the sensors used in the control system are needed. Finally, an experimental evaluation is presented by using a solar array simulator dc power supply and a boost dc/dc converter of 175 W in order to validate the ideas this study exposes.

  9. Electrothermal Feedback and Absorption-Induced Open-Circuit-Voltage Turnover in Solar Cells

    Science.gov (United States)

    Ullbrich, Sascha; Fischer, Axel; Tang, Zheng; Ávila, Jorge; Bolink, Henk J.; Reineke, Sebastian; Vandewal, Koen

    2018-05-01

    Solar panels easily heat up upon intense solar radiation due to excess energy dissipation of the absorbed photons or by nonradiative recombination of charge carriers. Still, photoinduced self-heating is often ignored when characterizing lab-sized samples. For light-intensity-dependent measurements of the open-circuit voltage (Suns-VO C ), allowing us to characterize the recombination mechanism, sample heating is often not considered, although almost 100% of the absorbed energy is converted into heat. Here, we show that the frequently observed stagnation or even decrease in VOC at increasingly high light intensities can be explained by considering an effective electrothermal feedback between the recombination current and the open-circuit voltage. Our analytical model fully explains the experimental data for various solar-cell technologies, comprising conventional inorganic semiconductors as well as organic and perovskite materials. Furthermore, the model can be exploited to determine the ideality factor, the effective gap, and the temperature rise from a single Suns-VOC measurement at ambient conditions.

  10. Open circuit voltage durability study and model of catalyst coated membranes at different humidification levels

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, Sumit; Fowler, Michael W.; Simon, Leonardo C. [Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario (Canada); Abouatallah, Rami; Beydokhti, Natasha [Hydrogenics Corporation, 5985 McLaughlin Road, Mississauga, Ontario (Canada)

    2010-11-01

    Fuel cell material durability is an area of extensive research today. Chemical degradation of the ionomer membrane is one important degradation mechanism leading to overall failure of fuel cells. This study examined the effects of relative humidity on the chemical degradation of the membrane during open circuit voltage testing. Five Gore trademark PRIMEA {sup registered} series 5510 catalyst coated membranes were degraded at 100%, 75%, 50%, and 20% RH. Open circuit potential and cumulative fluoride release were monitored over time. Additionally scanning electron microscopy images were taken at end of the test. The results showed that with decreasing RH fluoride release rate increased as did performance degradation. This was attributed to an increase in gas crossover with a decrease in RH. Further, it is also shown that interruptions in testing may heavily influence cumulative fluoride release measurements where frequent stoppages in testing will cause fluoride release to be underestimated. SEM analysis shows that degradation occurred in the ionomer layer close to the cathode catalyst. A chemical degradation model of the ionomer membrane was used to model the results. The model was able to predict fluoride release trends, including the effects of interruptions, showing that changes in gas crossover with RH could explain the experimental results. (author)

  11. Single-nanowire, low-bandgap hot carrier solar cells with tunable open-circuit voltage

    Science.gov (United States)

    Limpert, Steven; Burke, Adam; Chen, I.-Ju; Anttu, Nicklas; Lehmann, Sebastian; Fahlvik, Sofia; Bremner, Stephen; Conibeer, Gavin; Thelander, Claes; Pistol, Mats-Erik; Linke, Heiner

    2017-10-01

    Compared to traditional pn-junction photovoltaics, hot carrier solar cells offer potentially higher efficiency by extracting work from the kinetic energy of photogenerated ‘hot carriers’ before they cool to the lattice temperature. Hot carrier solar cells have been demonstrated in high-bandgap ferroelectric insulators and GaAs/AlGaAs heterostructures, but so far not in low-bandgap materials, where the potential efficiency gain is highest. Recently, a high open-circuit voltage was demonstrated in an illuminated wurtzite InAs nanowire with a low bandgap of 0.39 eV, and was interpreted in terms of a photothermoelectric effect. Here, we point out that this device is a hot carrier solar cell and discuss its performance in those terms. In the demonstrated devices, InP heterostructures are used as energy filters in order to thermoelectrically harvest the energy of hot electrons photogenerated in InAs absorber segments. The obtained photovoltage depends on the heterostructure design of the energy filter and is therefore tunable. By using a high-resistance, thermionic barrier, an open-circuit voltage is obtained that is in excess of the Shockley-Queisser limit. These results provide generalizable insight into how to realize high voltage hot carrier solar cells in low-bandgap materials, and therefore are a step towards the demonstration of higher efficiency hot carrier solar cells.

  12. Explosively formed fuse opening switches for use in flux-compression generator circuits

    International Nuclear Information System (INIS)

    Goforth, J.H.; Marsh, S.P.

    1990-01-01

    Explosive-driven magnetic flux compression generators (explosive generators) provide for the generation of large amounts of energy compactly stored in a magnetic field. Opening switches for use in explosive generator circuits allow the energy to be used for applications requiring higher power than can be developed by the generators themselves. The authors have developed a type of opening switch that they describe as an explosively formed fuse (EEF). These switches are well suited to explosive generator circuits and provide a considerable enhancement of explosive pulsed-power capability. The authors first experiments with explosively formed fuses occurred while attempting to utilize the enhanced pressure developed in the high-pressure interaction between two detonation fronts. In these tests they attempted to use the interaction to sever conducting plates along lines perpendicular to current flow. The technique worked to some extent, and to ascertain how much advantage was gained from the high-pressure interaction, they substituted an areal detonation in place of the discrete lines required to produce lines of interaction. This paper describes the authors development effort, the state of the art, and the different manifestations of their technique

  13. Coupled circuit numerical analysis of eddy currents in an open MRI system

    Science.gov (United States)

    Akram, Md. Shahadat Hossain; Terada, Yasuhiko; Keiichiro, Ishi; Kose, Katsumi

    2014-08-01

    We performed a new coupled circuit numerical simulation of eddy currents in an open compact magnetic resonance imaging (MRI) system. Following the coupled circuit approach, the conducting structures were divided into subdomains along the length (or width) and the thickness, and by implementing coupled circuit concepts we have simulated transient responses of eddy currents for subdomains in different locations. We implemented the Eigen matrix technique to solve the network of coupled differential equations to speed up our simulation program. On the other hand, to compute the coupling relations between the biplanar gradient coil and any other conducting structure, we implemented the solid angle form of Ampere’s law. We have also calculated the solid angle for three dimensions to compute inductive couplings in any subdomain of the conducting structures. Details of the temporal and spatial distribution of the eddy currents were then implemented in the secondary magnetic field calculation by the Biot-Savart law. In a desktop computer (Programming platform: Wolfram Mathematica 8.0®, Processor: Intel(R) Core(TM)2 Duo E7500 @ 2.93 GHz; OS: Windows 7 Professional; Memory (RAM): 4.00 GB), it took less than 3 min to simulate the entire calculation of eddy currents and fields, and approximately 6 min for X-gradient coil. The results are given in the time-space domain for both the direct and the cross-terms of the eddy current magnetic fields generated by the Z-gradient coil. We have also conducted free induction decay (FID) experiments of eddy fields using a nuclear magnetic resonance (NMR) probe to verify our simulation results. The simulation results were found to be in good agreement with the experimental results. In this study we have also conducted simulations for transient and spatial responses of secondary magnetic field induced by X-gradient coil. Our approach is fast and has much less computational complexity than the conventional electromagnetic numerical

  14. Online Open Circuit Fault Diagnosis for Rail Transit Traction Converter Based on Object-Oriented Colored Petri Net Topology Reasoning

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2016-01-01

    Full Text Available For online open circuit fault diagnosis of the traction converter in rail transit vehicles, conventional approaches depend heavily on component parameters and circuit layouts. For better universality and less parameter sensitivity during the diagnosis, this paper proposes a novel topology analysis approach to diagnose switching device open circuit failures. During the diagnosis, the topology is analyzed with fault reasoning mechanism, which is based on object-oriented Petri net (OOCPN. The OOCPN model takes in digitalized current inputs as fault signatures, and dynamical transitions between discrete switching states of a circuit with broken device are symbolized with the dynamical transitions of colored tokens in OOCPN. Such transitions simulate natural reasoning process of an expert’s brain during diagnosis. The dependence on component parameters and on circuit layouts is finally eliminated by such circuit topology reasoning process. In the last part, the proposed online reasoning and diagnosis process is exemplified with the case of a certain switching device failure in the power circuit of traction converter.

  15. Molecular understanding of the open-circuit voltage of polymer: Fullerene solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Shunsuke; Orimo, Akiko; Benten, Hiroaki; Ito, Shinzaburo [Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo, Kyoto (Japan); Ohkita, Hideo [Japan Science and Technology Agency (JST), PRESTO, Saitama (Japan); Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo, Kyoto (Japan)

    2012-02-15

    The origin of open-circuit voltage (V{sub OC}) was studied for polymer solar cells based on a blend of poly(3-hexylthiophene) (P3HT) and seven fullerene derivatives with different LUMO energy levels and side chains. The temperature dependence of J-V characteristics was analyzed by an equivalent circuit model. As a result, V{sub OC} increased with the decrease in the saturation current density J{sub 0} of the device. Furthermore, J{sub 0} was dependent on the activation energy E{sub A} for J{sub 0}, which is related to the HOMO-LUMO energy gap between P3HT and fullerene. Interestingly, the pre-exponential term J{sub 00} for J{sub 0} was larger for pristine fullerenes than for substituted fullerene derivatives, suggesting that the electronic coupling between molecules also has substantial impact on V{sub OC}. This is probably because the recombination is non-diffusion-limited reaction depending on electron transfer at the P3HT/fullerene interface. In summary, the origin of V{sub OC} is ascribed not only to the relative HOMO-LUMO energy gap but also to the electronic couplings between fullerene/fullerene and polymer/fullerene. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Safety of wet welding with increased open circuit voltages up to 150 V d.c

    International Nuclear Information System (INIS)

    Schmidt, K.; Kozig, G.; Ross, J.A.S.; Green, H.L.

    1991-01-01

    An experimental test programme was performed to demonstrate that wet welding with open circuit voltages up to 150 V d.c. would not result in dangerous situations for the diver induced by electric shock. Sea water, fresh water, different types of diving suits and some worst case situations, resulting from a disregard of good working practice were considered to be test parameters. In sea water a diver will not be endangered by corresponding electric potentials if good working practice is adopted. This was demonstrated even for worst case conditions, e.g. water leakage into the dry suit, accidental positioning to the diver between torch and work piece (stretched arm) and partial removal of coating from the welding rod. The fresh water tests demonstrated higher voltages on the diver but well below accepted threshold limit values. The term 'fresh water' should be critically considered, however, the test results relate only to the water conductivity studied. (orig.) With 30 figs [de

  17. Utilization of the heat of mixing in open-circuit throttle refrigerators

    International Nuclear Information System (INIS)

    Zhakharov, N.D.; Anikeev, G.N.; Grezin, A.K.

    1986-01-01

    Open-circuit throttle refrigerators based on gas mixtures operate, as a rule, according to a single-stream scheme. The refrigerating effect is determined by the isothermal throttling effect of the mixture in the cylinder under the conditions at the inlet to the cryogenic unit. The authors use the heat of mixing of the cryogenic mixtures to increase the available refrigerating effect. Data are presented on mixtures of nitrogen and Freon-13; the thermodynamic properties of these compounds have been investigated experimentally over a wide range of parameters. It was found that in the case of correct selection of the scheme and complex optimization of the parameters, two-stream throttle refrigerators exceed the single-stream throttle refrigerators by at least a factor of 1.5 with respect to relative useful energy. With account taken of the design, technological, and operational parameters, that which is most promising is the scheme with mixing of the components in reverse flow

  18. Open Circuit Potential Study of Stainless Steel in Environment Containing Marine Sulphate-Reducing Bacteria

    International Nuclear Information System (INIS)

    Fathul Karim Sahrani; Madzlan Abd. Aziz; Zaharah Ibrahim; Adibah Yahya

    2008-01-01

    The corrosion potential of AISI 304 stainless steel coupons influenced by sulphate-reducing bacteria (SRB) has been studied. Pure colony of SRB was isolated from the Malaysia Marine and Heavy Engineering, Pasir Gudang, Johor. Open circuit potential measurements were carried out in variable types of culturing solutions with SRB1, SRB2, combination of SRB1 and SRB2 and without SRBs inoculated. Results showed that the corrosion potential, E oc increased in the presence of SRBs (in pure and mixed culture) compared to that of control. EDS analysis showed the strong peak of sulphur in coupon containing SRB cultures compared to the control. ESEM data showed that the high density cell of SRBs were associated with corroding sections of surface steel comparing with non-corroding sections for coupons immersed in VMNI medium containing SRBs. (author)

  19. Open circuit potential monitored digital photocorrosion of GaAs/AlGaAs quantum well microstructures

    Science.gov (United States)

    Aithal, Srivatsa; Dubowski, Jan J.

    2018-04-01

    Nanostructuring of semiconductor wafers with an atomic level depth resolution is a challenging task, primarily due to the limited availability of instruments for in situ monitoring of such processes. Conventional digital etching relies on calibration procedures and cumbersome diagnostics applied between or at the end of etching cycles. We have developed a photoluminescence (PL) based process for monitoring in situ digital photocorrosion (DPC) of GaAs/AlGaAs microstructures at rates below 0.2 nm per cycle. In this communication, we demonstrate that DPC of GaAs/AlGaAs microstructures could be monitored with open circuit potential (OCP) measured between the photocorroding surface of a microstructure and an Ag/AgCl reference electrode installed in the sample chamber. The excellent correlation between the position of both PL and OCP maxima indicates that the DPC process could be monitored in situ for materials that do not necessarily exhibit measurable PL emission.

  20. Stacking Orientation Mediation of Pentacene and Derivatives for High Open-Circuit Voltage Organic Solar Cells.

    Science.gov (United States)

    Chou, Chi-Ta; Lin, Chien-Hung; Tai, Yian; Liu, Chin-Hsin J; Chen, Li-Chyong; Chen, Kuei-Hsien

    2012-05-03

    In this Letter, we investigated the effect of the molecular stacking orientation on the open circuit voltage (VOC) of pentacene-based organic solar cells. Two functionalized pentacenes, namely, 6,13-diphenyl-pentacene (DP-penta) and 6,13-dibiphenyl-4-yl-pentacene (DB-penta), were utilized. Different molecular stacking orientations of the pentacene derivatives from the pristine pentacene were identified by angle-dependent near-edge X-ray absorption fine structure measurements. It is concluded that pentacene molecules stand up on the substrate surface, while both functionalized pentacenes lie down. A significant increase of the VOC from 0.28 to 0.83 V can be achieved upon the utilization of functionalized pentacene, owing to the modulation of molecular stacking orientation, which induced a vacuum-level shift.

  1. Resonant magnetoelectric response of composite cantilevers: Theory of short vs. open circuit operation and layer sequence effects

    Directory of Open Access Journals (Sweden)

    Matthias C. Krantz

    2015-11-01

    Full Text Available The magnetoelectric effect in layered composite cantilevers consisting of strain coupled layers of magnetostrictive (MS, piezoelectric (PE, and substrate materials is investigated for magnetic field excitation at bending resonance. Analytic theories are derived for the transverse magnetoelectric (ME response in short and open circuit operation for three different layer sequences and results presented and discussed for the FeCoBSi-AlN-Si and the FeCoBSi-PZT-Si composite systems. Response optimized PE-MS layer thickness ratios are found to greatly change with operation mode shifting from near equal MS and PE layer thicknesses in the open circuit mode to near vanishing PE layer thicknesses in short circuit operation for all layer sequences. In addition the substrate layer thickness is found to differently affect the open and short circuit ME response producing shifts and reversal between ME response maxima depending on layer sequence. The observed rich ME response behavior for different layer thicknesses, sequences, operating modes, and PE materials can be explained by common neutral plane effects and different elastic compliance effects in short and open circuit operation.

  2. Origin of Reduced Open-Circuit Voltage in Highly Efficient Small-Molecule-Based Solar Cells upon Solvent Vapor Annealing.

    Science.gov (United States)

    Deng, Wanyuan; Gao, Ke; Yan, Jun; Liang, Quanbin; Xie, Yuan; He, Zhicai; Wu, Hongbin; Peng, Xiaobin; Cao, Yong

    2018-03-07

    In this study, we demonstrate that remarkably reduced open-circuit voltage in highly efficient organic solar cells (OSCs) from a blend of phenyl-C 61 -butyric acid methyl ester and a recently developed conjugated small molecule (DPPEZnP-THD) upon solvent vapor annealing (SVA) is due to two independent sources: increased radiative recombination and increased nonradiative recombination. Through the measurements of electroluminescence due to the emission of the charge-transfer state and photovoltaic external quantum efficiency measurement, we can quantify that the open-circuit voltage losses in a device with SVA due to the radiative recombination and nonradiative recombination are 0.23 and 0.31 V, respectively, which are 0.04 and 0.07 V higher than those of the as-cast device. Despite of the reduced open-circuit voltage, the device with SVA exhibited enhanced dissociation of charge-transfer excitons, leading to an improved short-circuit current density and a remarkable power conversion efficiency (PCE) of 9.41%, one of the best for solution-processed OSCs based on small-molecule donor materials. Our study also clearly shows that removing the nonradiative recombination pathways and/or suppressing energetic disorder in the active layer would result in more long-lived charge carriers and enhanced open-circuit voltage, which are prerequisites for further improving the PCE.

  3. Offset energies at organic semiconductor heterojunctions and their influence on the open-circuit voltage of thin-film solar cells

    Science.gov (United States)

    Rand, Barry P.; Burk, Diana P.; Forrest, Stephen R.

    2007-03-01

    Organic semiconductor heterojunction (HJ) energy level offsets are modeled using a combination of Marcus theory for electron transfer, and generalized Shockley theory of the dark current density vs voltage (J-V) characteristics. This model is used to fit the J-V characteristics of several donor-acceptor combinations commonly used in thin film organic photovoltaic cells. In combination with measurements of the energetics of donor-acceptor junctions, the model predicts tradeoffs between the junction open-circuit voltage (VOC) and short-circuit current density (JSC) . The VOC is found to increase with light intensity and inversely with temperature for 14 donor-acceptor HJ materials pairs. In particular, we find that VOC reaches a maximum at low temperature (˜175K) for many of the heterojunctions studied. The maximum value of VOC is a function of the difference between the donor ionization potential and acceptor electron affinity, minus the binding energy of the dissociated, geminate electron-hole pair: a general relationship that has implications on the charge transfer mechanism at organic heterojunctions. The fundamental understanding provided by this model leads us to infer that the maximum power conversion efficiency of double heterostructure organic photovoltaic cells can be as high as 12%. When combined with mixed layers to increase photocurrent and stacked cells to increase VOC , efficiencies approaching 16% are within reach.

  4. Reduced voltage losses yield 10% efficient fullerene free organic solar cells with >1 V open circuit voltages

    KAUST Repository

    Baran, D.; Kirchartz, T.; Wheeler, S.; Dimitrov, S.; Abdelsamie, Maged; Gorman, J.; Ashraf, Raja; Holliday, S.; Wadsworth, A.; Gasparini, N.; Kaienburg, P.; Yan, H.; Amassian, Aram; Brabec, C. J.; Durrant, J. R.; McCulloch, Iain

    2016-01-01

    of high recombination losses, which empirically limit the open-circuit voltage (Voc) to typically less than 1 V. Here we show that this empirical limit can be overcome using non-fullerene acceptors blended with the low band gap polymer PffBT4T-2DT leading

  5. Open-circuit fault detection and tolerant operation for a parallel-connected SAB DC-DC converter

    DEFF Research Database (Denmark)

    Park, Kiwoo; Chen, Zhe

    2014-01-01

    This paper presents an open-circuit fault detection method and its tolerant control strategy for a Parallel-Connected Single Active Bridge (PCSAB) dc-dc converter. The structural and operational characteristics of the PCSAB converter lead to several advantages especially for high power applicatio...

  6. 77 FR 37862 - Open-Circuit Self-Contained Breathing Apparatus Remaining Service-Life Indicator Performance...

    Science.gov (United States)

    2012-06-25

    .... Executive Order 13211 (Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution... obstructive pulmonary disease, silicosis, neurological disorders, and cancer. Open-circuit self-contained... result in an annual effect on the economy of $100 million or more. E. Unfunded Mandates Reform Act of...

  7. Interface Modification of Dye-sensitized Solar Cells with Pivalic Acid to Enhance the Open-circuit Voltage

    KAUST Repository

    Li, Xin

    2009-01-01

    Pivalic acid (PVA) was used as a new coadsorbent to dye-sensitized solar cells (DSCs) to modify the interface between the TiO2 films and electrolyte. The addition of PVA improved the light-to-electricity conversion efficiency of devices by 8% by enhancing the open-circuit voltage. Copyright © 2009 The Chemical Society of Japan.

  8. Effect of dislocations on the open-circuit voltage, short-circuit current and efficiency of heteroepitaxial indium phosphide solar cells

    Science.gov (United States)

    Jain, Raj K.; Flood, Dennis J.

    1990-01-01

    Excellent radiation resistance of indium phosphide solar cells makes them a promising candidate for space power applications, but the present high cost of starting substrates may inhibit their large scale use. Thin film indium phosphide cells grown on Si or GaAs substrates have exhibited low efficiencies, because of the generation and propagation of large number of dislocations. Dislocation densities were calculated and its influence on the open circuit voltage, short circuit current, and efficiency of heteroepitaxial indium phosphide cells was studied using the PC-1D. Dislocations act as predominant recombination centers and are required to be controlled by proper transition layers and improved growth techniques. It is shown that heteroepitaxial grown cells could achieve efficiencies in excess of 18 percent AMO by controlling the number of dislocations. The effect of emitter thickness and surface recombination velocity on the cell performance parameters vs. dislocation density is also studied.

  9. Paleocene-Eocene Thermal Maximum and the Opening of the Northeast Atlantic

    DEFF Research Database (Denmark)

    Storey, Michael; Duncan, Robert A.; Swisher, III, Carl C.

    2007-01-01

    The Paleocene-Eocene thermal maximum (PETM) has been attributed to a sudden release of carbon dioxide and/or methane. 40Ar/39Ar age determinations show that the Danish Ash-17 deposit, which overlies the PETM by about 450,000 years in the Atlantic, and the Skraenterne Formation Tuff, representing ...

  10. Symmetry-Breaking Charge Transfer in a Zinc Chlorodipyrrin Acceptor for High Open Circuit Voltage Organic Photovoltaics

    KAUST Repository

    Bartynski, Andrew N.

    2015-04-29

    © 2015 American Chemical Society. Low open-circuit voltages significantly limit the power conversion efficiency of organic photovoltaic devices. Typical strategies to enhance the open-circuit voltage involve tuning the HOMO and LUMO positions of the donor (D) and acceptor (A), respectively, to increase the interfacial energy gap or to tailor the donor or acceptor structure at the D/A interface. Here, we present an alternative approach to improve the open-circuit voltage through the use of a zinc chlorodipyrrin, ZCl [bis(dodecachloro-5-mesityldipyrrinato)zinc], as an acceptor, which undergoes symmetry-breaking charge transfer (CT) at the donor/acceptor interface. DBP/ZCl cells exhibit open-circuit voltages of 1.33 V compared to 0.88 V for analogous tetraphenyldibenzoperyflanthrene (DBP)/C60-based devices. Charge transfer state energies measured by Fourier-transform photocurrent spectroscopy and electroluminescence show that C60 forms a CT state of 1.45 ± 0.05 eV in a DBP/C60-based organic photovoltaic device, while ZCl as acceptor gives a CT state energy of 1.70 ± 0.05 eV in the corresponding device structure. In the ZCl device this results in an energetic loss between ECT and qVOC of 0.37 eV, substantially less than the 0.6 eV typically observed for organic systems and equal to the recombination losses seen in high-efficiency Si and GaAs devices. The substantial increase in open-circuit voltage and reduction in recombination losses for devices utilizing ZCl demonstrate the great promise of symmetry-breaking charge transfer in organic photovoltaic devices.

  11. Maximum mouth opening and trismus in 143 patients treated for oral cancer: a 1-year prospective study.

    Science.gov (United States)

    Wetzels, Jan-Willem G H; Merkx, Matthias A W; de Haan, Anton F J; Koole, Ron; Speksnijder, Caroline M

    2014-12-01

    Patients with oral cancer can develop restricted mouth opening (trismus) because of the oncologic treatment. Maximum mouth opening (MMO) was measured in 143 patients shortly before treatment and 0, 6, and 12 months posttreatment, and the results were analyzed using a linear mixed-effects model. In every patient, MMO decreased after treatment. The patients who underwent surgery, recovered partially by 6 and 12 months after treatment, whereas the patients who received both surgery and radiotherapy or primary radiotherapy did not recover. Tumor location, tumor size, and alcohol consumption had independent effects on MMO. Having trismus (MMO oral cancer treatment. © 2014 Wiley Periodicals, Inc.

  12. Electrochemical Immunoassay Using Open Circuit Potential Detection Labeled by Platinum Nanoparticles

    Directory of Open Access Journals (Sweden)

    Kanokwan Charoenkitamorn

    2018-02-01

    Full Text Available In this work, a simple electrochemical immunoassay based on platinum nanoparticles (PtNPs using open circuit potential (OCP detection was developed. The detection of human chorionic gonadotropin hormone (hCG as a model analyte, was demonstrated by direct electrical detection of PtNPs in hydrazine solution using OCP measurement without any application of either potential or current to the system. Disposable screen-printed carbon electrodes (SPCEs were utilized for the development of our immunosensor, which required a sample volume as small as 2 μL. After preparation of a sandwich-type immunosystem, hydrazine solution was dropped on the electrode’s surface, which was followed immediately by electrical detection using OCP. The change of the OCP signal originated from electrocatalytic oxidation of the hydrazine on PtNPs. Under the optimal conditions of a pH of 6.0 and a hydrazine concentration of 1 mM, a detection limit of 0.28 ng mL−1 and a linearity of 0–10 ng mL−1 were obtained. The PtNP-based OCP method is a simpler electrochemical detection procedure than those obtained from other electrochemical methods and has an acceptable sensitivity and reproducibility. The simplicity of the detection procedure and the cost-effectiveness of the disposable SPCE illustrate the attractive benefits of this sensor. Moreover, it could be applied to a simplified and miniaturized diagnostic system with minimal user manipulation.

  13. Copper and brass aged at open circuit potential in slightly alkaline solutions

    International Nuclear Information System (INIS)

    Procaccini, R.; Vazquez, M.; Cere, S.

    2009-01-01

    Surface oxide films were grown on 99.99% copper and brass (copper-zinc alloy, Cu77Zn21Al2) in 0.1 mol L -1 borax solution at open circuit potential and were characterized using various experimental techniques. The composition of the passive films formed in situ on the different materials was studied using differential reflectance spectroscopy. The thickness of the oxide layers on copper and brass was compared by chronopotentiometric curves and potentiodynamic reductions. The electrical properties of each oxide were analyzed by means of electrochemical impedance spectroscopy. Their influence on the oxygen reduction reaction was also investigated using voltammetry hydrodynamic tools such as the rotating disk electrode. The results show that the incorporation of Zn to Cu in brass changes the composition and the thickness of the surface film. The films grown on brass tend to be thicker but less resistive and Zn compounds incorporate to the film. This is supported by results from reflectance and impedance spectroscopy. The kinetics of oxygen reduction is strongly inhibited on oxidized electrodes, particularly in the case of brass. The global number of exchanged electrons remains close to four and seems to be independent of the presence of surface oxides.

  14. Wireless Open-Circuit In-Plane Strain and Displacement Sensor Requiring No Electrical Connections

    Science.gov (United States)

    Woodard, Stanley E. (Inventor)

    2014-01-01

    A wireless in-plane strain and displacement sensor includes an electrical conductor fixedly coupled to a substrate subject to strain conditions. The electrical conductor is shaped between its ends for storage of an electric field and a magnetic field, and remains electrically unconnected to define an unconnected open-circuit having inductance and capacitance. In the presence of a time-varying magnetic field, the electrical conductor so-shaped resonates to generate harmonic electric and magnetic field responses. The sensor also includes at least one electrically unconnected electrode having an end and a free portion extending from the end thereof. The end of each electrode is fixedly coupled to the substrate and the free portion thereof remains unencumbered and spaced apart from a portion of the electrical conductor so-shaped. More specifically, at least some of the free portion is disposed at a location lying within the magnetic field response generated by the electrical conductor. A motion guidance structure is slidingly engaged with each electrode's free portion in order to maintain each free portion parallel to the electrical conductor so-shaped.

  15. Effect of nano-imprinting on open-circuit voltage of organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Emah, J.B.; Curry, R.J.; Silva, S.R.P. [Surrey Univ., Guildford (United Kingdom). Advanced Technology Inst.

    2010-07-01

    The open-circuit voltage (V{sub oc}) of solar cells with non-Ohmic contacts are determined by the work function difference of the electrodes. For Ohmic contacts the V{sub oc} is governed by the LUMO and HOMO levels of the acceptor and donor, respectively, which pin the Fermi levels of the cathode and anode. We present a case where the V{sub oc} of a single layer device using poly (3-hexylthiopene-2,5-diyl) (P3HT) as the photoactive material between a nanoimprinted poly poly (3,4-ethylenedioxythiophene) poly (styrene sulfonate)(PEDOT:PSS) and Al electrode decreases due to patterning. The reverse is shown to be the case when [6,6]-phenyl-C{sub 61}-butyric acid ester (PCBM) is introduced to form a bulk heterojunction (BHJ). In both scenarios, there is an increase in the short-circuit current, attributed to an extended optical path length within the photoactive layer and enhanced charge extraction through the increased surface area. The patterned BHJ devices show a 28% and 40% increase in the power conversion efficiency when imprinted with 727 nm and 340 nm periodic patterns respectively. ATR-FTIR investigations of the interfacial PEDOT:PSS film following patterning reveals the presence of PDMS residue which is supported by consideration of the effect on single layer P3HT and P3HT:PCBM blend device performance. UPS measurements demonstrate a reduction in the work function of the interfacial PEDOT:OSS layer by {proportional_to}0.5 eV following nanoimprinting which may originate from chemical modification by the PDMS residue or interfacial dipole formation. XPS spectrum of the imprinted PEDOT:PSS also shows a chemical shift in the 0(1s) core-level towards higher binding energy signifying interaction of the PDMS stamp residue with the PSS dominated surface of PEDOT:PSS. This led to significant improvement in the V{sub oc} and ultimately, the PCE. (orig.)

  16. Study on evaluation of normal range of maximum mouth opening among Indian adults using three finger index: A descriptive study

    Directory of Open Access Journals (Sweden)

    Ravleen Nagi

    2017-01-01

    Full Text Available Introduction: Early recognition of decreased or limited mouth opening in many pathological conditions is necessary for prompt diagnosis and to plan the treatment options judiciously. Therefore, it is essential to establish what constitutes normal opening for the population. Aim: This study was designed with an aim to consider the applicability of this method as an index to measure the maximum mouth opening (MMO among different age groups in an Indian population. Materials and Methods: Total 400 healthy participants were studied in the age range of 17 to 60 years and stratified into four groups according to their age ranges. The maximum interincisal distance and width of three fingers (index, middle, and ring fingers at the first distal interphalangeal folds of both right and left hand were measured using Vernier caliper. Statistical analysis was done using SPSS version 21 software package. Results: Results suggested that mean value and range of MMO for males was 51.00 mm (33.0–68.0 mm and for females it was 46.3 mm (39.0–58.0 mm. Mean values of MMO correlated significantly with the width of three fingers of left and right hand as shown by Pearson correlation test. Conclusion: The study suggested that three finger index is a convenient and reliable tool for assessing normal MMO and is a most appropriate method to normal from restricted mouth opening.

  17. Improved open-circuit voltage in Cu(In,Ga)Se2 solar cells with high work function transparent electrodes

    International Nuclear Information System (INIS)

    Jäger, Timo; Romanyuk, Yaroslav E.; Bissig, Benjamin; Pianezzi, Fabian; Nishiwaki, Shiro; Reinhard, Patrick; Steinhauser, Jérôme; Tiwari, Ayodhya N.; Schwenk, Johannes

    2015-01-01

    Hydrogenated indium oxide (IOH) is implemented as transparent front contact in Cu(In,Ga)Se 2 (CIGS) solar cells, leading to an open circuit voltage V OC enhanced by ∼20 mV as compared to reference devices with ZnO:Al (AZO) electrodes. This effect is reproducible in a wide range of contact sheet resistances corresponding to various IOH thicknesses. We present the detailed electrical characterization of glass/Mo/CIGS/CdS/intrinsic ZnO (i-ZnO)/transparent conductive oxide (TCO) with different IOH/AZO ratios in the front TCO contact in order to identify possible reasons for the enhanced V OC . Temperature and illumination intensity-dependent current-voltage measurements indicate that the dominant recombination path does not change when AZO is replaced by IOH, and it is mainly limited to recombination in the space charge region and at the junction interface of the solar cell. The main finding is that the introduction of even a 5 nm-thin IOH layer at the i-ZnO/TCO interface already results in a step-like increase in V OC . Two possible explanations are proposed and verified by one-dimensional simulations using the SCAPS software. First, a higher work function of IOH as compared to AZO is simulated to yield an V OC increase by 21 mV. Second, a lower defect density in the i-ZnO layer as a result of the reduced sputter damage during milder sputter-deposition of IOH can also add to a maximum enhanced V OC of 25 mV. Our results demonstrate that the proper choice of the front TCO contact can reduce the parasitic recombination and boost the efficiency of CIGS cells with improved corrosion stability

  18. Experimental investigation of open circuit voltage during start-up process of HT-PEMFC

    International Nuclear Information System (INIS)

    Abdul Rasheed, Raj Kamal; Chan, Siew Hwa

    2015-01-01

    Highlights: • OCV reduces non-linearly with temperature under constant power input. • The reduction gradient of OCV is observed to be non-linear with time. • Nernst equation is less accurate for HT-PEMFC start-up models. - Abstract: This paper investigates the open circuit voltage (OCV) during the warm-up process of a high temperature proton exchange membrane fuel cell (HT-PEMFC) from 140 °C to the desired temperature of 180 °C, where the temperature increases with time. The heating strategy involves the external heating of the fuel cell with constant heat input rate. The commonly used Nernst equation, to predict the OCV of the fuel cell, is usually used in transient start-up models. Thus, this papers highlights the limitations of using the Nernst equation where the temperature increases transiently with time. A polybenzimidazole-based HTPEM single cell was set up and the OCV was measured under constant heating power supplied by an external source. A parametric study was done by varying the external heating power and the effect on the OCV was observed. The results showed that the OCV reduces non-linearly with respect to temperature, when the fuel cell is subjected to a constant heating power. This behaviour is clearly in contrast with the Nernst equation, which considers the temperature as steady state. For effective comparison, the OCV was also measured under steady state temperatures, showing an almost constant reduction gradient of ∼ −2.3×10 −4 V/°C. However, the behaviour under a constant heating power show curvilinear reduction of the OCV as the temperature increases. In addition, as the external heating power is increased, the degree of curvature of the OCV profile is greater. Thus, the results clearly indicate that the accuracy of using the Nernst equation in transient thermal start-up models can be improved, by considering a non linear behaviour, as shown in this paper.

  19. Open-circuit respirometry: real-time, laboratory-based systems.

    Science.gov (United States)

    Ward, Susan A

    2018-05-04

    This review explores the conceptual and technological factors integral to the development of laboratory-based, automated real-time open-circuit mixing-chamber and breath-by-breath (B × B) gas-exchange systems, together with considerations of assumptions and limitations. Advances in sensor technology, signal analysis, and digital computation led to the emergence of these technologies in the mid-20th century, at a time when investigators were beginning to recognise the interpretational advantages of nonsteady-state physiological-system interrogation in understanding the aetiology of exercise (in)tolerance in health, sport, and disease. Key milestones include the 'Auchincloss' description of an off-line system to estimate alveolar O 2 uptake B × B during exercise. This was followed by the first descriptions of real-time automated O 2 uptake and CO 2 output B × B measurement by Beaver and colleagues and by Linnarsson and Lindborg, and mixing-chamber measurement by Wilmore and colleagues. Challenges to both approaches soon emerged: e.g., the influence of mixing-chamber washout kinetics on mixed-expired gas concentration determination, and B × B alignment of gas-concentration signals with respired flow. The challenging algorithmic and technical refinements required for gas-exchange estimation at the alveolar level have also been extensively explored. In conclusion, while the technology (both hardware and software) underpinning real-time automated gas-exchange measurement has progressively advanced, there are still concerns regarding accuracy especially under the challenging conditions of changing metabolic rate.

  20. Maximum opening of the mouth by mouth prop during dental procedures increases the risk of upper airway constriction

    Directory of Open Access Journals (Sweden)

    Hiroshi Ito

    2010-05-01

    Full Text Available Hiroshi Ito1, Hiroyoshi Kawaai1, Shinya Yamazaki1, Yosuke Suzuki21Division of Systemic Management, Department of Oral Function, 2Division of Radiology and Diagnosis, Department of Medical Sciences, Ohu University, Post Graduate School of Dentistry, Koriyama City, Fukushima Prefecture, JapanAbstract: From a retrospective evaluation of data on accidents and deaths during dental procedures, it has been shown that several patients who refused dental treatment died of asphyxia during dental procedures. We speculated that forcible maximum opening of the mouth by using a mouth prop triggers this asphyxia by affecting the upper airway. Therefore, we assessed the morphological changes of the upper airway following maximal opening of the mouth. In 13 healthy adult volunteers, the sagittal diameter of the upper airway on lateral cephalogram was measured between the two conditions; closed mouth and maximally open mouth. The dyspnea in each state was evaluated by a visual analog scale. In one subject, a computed tomograph (CT was taken to assess the three-dimensional changes in the upper airway. A significant difference was detected in the mean sagittal diameter of the upper airway following use of the prop (closed mouth: 18.5 ± 3.8 mm, maximally open mouth: 10.4 ± 3.0 mm. All subjects indicated upper airway constriction and significant dyspnea when their mouth was maximally open. Although a CT scan indicated upper airway constriction when the mouth was maximally open, muscular compensation was admitted. Our results further indicate that the maximal opening of the mouth narrows the upper airway diameter and leads to dyspnea. The use of a prop for the patient who has communication problems or poor neuromuscular function can lead to asphyxia. When the prop is used for patient refusal in dentistry, the respiratory condition should be monitored strictly, and it should be kept in mind that the “sniffing position” is effective for avoiding upper airway

  1. The effect of diffusion induced lattice stress on the open-circuit voltage in silicon solar cells

    Science.gov (United States)

    Weizer, V. G.; Godlewski, M. P.

    1984-01-01

    It is demonstrated that diffusion induced stresses in low resistivity silicon solar cells can significantly reduce both the open-circuit voltage and collection efficiency. The degradation mechanism involves stress induced changes in both the minority carrier mobility and the diffusion length. Thermal recovery characteristics indicate that the stresses are relieved at higher temperatures by divacancy flow (silicon self diffusion). The level of residual stress in as-fabricated cells was found to be negligible in the cells tested.

  2. Guanidinium: A Route to Enhanced Carrier Lifetime and Open-Circuit Voltage in Hybrid Perovskite Solar Cells.

    Science.gov (United States)

    De Marco, Nicholas; Zhou, Huanping; Chen, Qi; Sun, Pengyu; Liu, Zonghao; Meng, Lei; Yao, En-Ping; Liu, Yongsheng; Schiffer, Andy; Yang, Yang

    2016-02-10

    Hybrid perovskites have shown astonishing power conversion efficiencies owed to their remarkable absorber characteristics including long carrier lifetimes, and a relatively substantial defect tolerance for solution-processed polycrystalline films. However, nonradiative charge carrier recombination at grain boundaries limits open circuit voltages and consequent performance improvements of perovskite solar cells. Here we address such recombination pathways and demonstrate a passivation effect through guanidinium-based additives to achieve extraordinarily enhanced carrier lifetimes and higher obtainable open circuit voltages. Time-resolved photoluminescence measurements yield carrier lifetimes in guanidinium-based films an order of magnitude greater than pure-methylammonium counterparts, giving rise to higher device open circuit voltages and power conversion efficiencies exceeding 17%. A reduction in defect activation energy of over 30% calculated via admittance spectroscopy and confocal fluorescence intensity mapping indicates successful passivation of recombination/trap centers at grain boundaries. We speculate that guanidinium ions serve to suppress formation of iodide vacancies and passivate under-coordinated iodine species at grain boundaries and within the bulk through their hydrogen bonding capability. These results present a simple method for suppressing nonradiative carrier loss in hybrid perovskites to further improve performances toward highly efficient solar cells.

  3. Damage Detection Response Characteristics of Open Circuit Resonant (SansEC) Sensors

    Science.gov (United States)

    Dudley, Kenneth L.; Szatkowski, George N.; Smith, Laura J.; Koppen, Sandra V.; Ely, Jay J.; Nguyen, Truong X.; Wang, Chuantong; Ticatch, Larry A.; Mielnik, John J.

    2013-01-01

    The capability to assess the current or future state of the health of an aircraft to improve safety, availability, and reliability while reducing maintenance costs has been a continuous goal for decades. Many companies, commercial entities, and academic institutions have become interested in Integrated Vehicle Health Management (IVHM) and a growing effort of research into "smart" vehicle sensing systems has emerged. Methods to detect damage to aircraft materials and structures have historically relied on visual inspection during pre-flight or post-flight operations by flight and ground crews. More quantitative non-destructive investigations with various instruments and sensors have traditionally been performed when the aircraft is out of operational service during major scheduled maintenance. Through the use of reliable sensors coupled with data monitoring, data mining, and data analysis techniques, the health state of a vehicle can be detected in-situ. NASA Langley Research Center (LaRC) is developing a composite aircraft skin damage detection method and system based on open circuit SansEC (Sans Electric Connection) sensor technology. Composite materials are increasingly used in modern aircraft for reducing weight, improving fuel efficiency, and enhancing the overall design, performance, and manufacturability of airborne vehicles. Materials such as fiberglass reinforced composites (FRC) and carbon-fiber-reinforced polymers (CFRP) are being used to great advantage in airframes, wings, engine nacelles, turbine blades, fairings, fuselage structures, empennage structures, control surfaces and aircraft skins. SansEC sensor technology is a new technical framework for designing, powering, and interrogating sensors to detect various types of damage in composite materials. The source cause of the in-service damage (lightning strike, impact damage, material fatigue, etc.) to the aircraft composite is not relevant. The sensor will detect damage independent of the cause

  4. Achieving 12.8% Efficiency by Simultaneously Improving Open-Circuit Voltage and Short-Circuit Current Density in Tandem Organic Solar Cells.

    Science.gov (United States)

    Qin, Yunpeng; Chen, Yu; Cui, Yong; Zhang, Shaoqing; Yao, Huifeng; Huang, Jiang; Li, Wanning; Zheng, Zhong; Hou, Jianhui

    2017-06-01

    Tandem organic solar cells (TOSCs), which integrate multiple organic photovoltaic layers with complementary absorption in series, have been proved to be a strong contender in organic photovoltaic depending on their advantages in harvesting a greater part of the solar spectrum and more efficient photon utilization than traditional single-junction organic solar cells. However, simultaneously improving open circuit voltage (V oc ) and short current density (J sc ) is a still particularly tricky issue for highly efficient TOSCs. In this work, by employing the low-bandgap nonfullerene acceptor, IEICO, into the rear cell to extend absorption, and meanwhile introducing PBDD4T-2F into the front cell for improving V oc , an impressive efficiency of 12.8% has been achieved in well-designed TOSC. This result is also one of the highest efficiencies reported in state-of-the-art organic solar cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Inter- and intra-rater reliability of 3D kinematics during maximum mouth opening of asymptomatic subjects.

    Science.gov (United States)

    Calixtre, Leticia Bojikian; Nakagawa, Theresa Helissa; Alburquerque-Sendín, Francisco; da Silva Grüninger, Bruno Leonardo; de Sena Rosa, Lianna Ramalho; Oliveira, Ana Beatriz

    2017-11-07

    Previous studies evaluated 3D human jaw movements using kinematic analysis systems during mouth opening, but information on the reliability of such measurements is still scarce. The purpose of this study was to analyze within- and between-session reliabilities, inter-rater reliability, standard error of measurement (SEM), minimum detectable change (MDC) and consistency of agreement across raters and sessions of 3D kinematic variables during maximum mouth opening (MMO). Thirty-six asymptomatic subjects from both genders were evaluated on two different days, five to seven days apart. Subjects performed three MMO movements while kinematic data were collected. Intraclass correlation coefficient (ICC), SEM and MDC were calculated for all variables, and Bland-Altman plots were constructed. Jaw radius and width were the most reproducible variables (ICC>0.81) and demonstrated minor error. Incisor displacement during MMO and angular movements in the sagittal plane presented good reliability (ICC from 0.61 to 0.8) and small errors and, consequently, could be used in future studies with the same methodology and population. The variables with smaller amplitudes (condylar translations during mouth opening and closing and mandibular movements on the frontal and transversal planes) were less reliable (ICCmandibular movements in the frontal and transversal planes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Photoluminescence and Photoconductivity to Assess Maximum Open-Circuit Voltage and Carrier Transport in Hybrid Perovskites and Other Photovoltaic Materials.

    Science.gov (United States)

    Braly, Ian L; Stoddard, Ryan J; Rajagopal, Adharsh; Jen, Alex K-Y; Hillhouse, Hugh W

    2018-06-06

    Photovoltaic (PV) device development is much more expensive and time consuming than the development of the absorber layer alone. This perspective focuses on two methods that can be used to rapidly assess and develop PV absorber materials independent of device development. The absorber material properties of quasi-Fermi level splitting and carrier diffusion length under steady effective one-Sun illumination are indicators of a material's ability to achieve high VOC and JSC. These two material properties can be rapidly and simultaneously assessed with steady-state absolute intensity photoluminescence and photoconductivity measurements. As a result, these methods are extremely useful for predicting the quality and stability of PV materials prior to PV device development. Here, we summarize the methods, discuss their strengths and weaknesses, and compare photoluminescence and photoconductivity results with device performance for four hybrid perovskite compositions of various bandgaps (1.35 to 1.82 eV), CISe, CIGSe, and CZTSe.

  7. Fault-Tolerant Control of ANPC Three-Level Inverter Based on Order-Reduction Optimal Control Strategy under Multi-Device Open-Circuit Fault.

    Science.gov (United States)

    Xu, Shi-Zhou; Wang, Chun-Jie; Lin, Fang-Li; Li, Shi-Xiang

    2017-10-31

    The multi-device open-circuit fault is a common fault of ANPC (Active Neutral-Point Clamped) three-level inverter and effect the operation stability of the whole system. To improve the operation stability, this paper summarized the main solutions currently firstly and analyzed all the possible states of multi-device open-circuit fault. Secondly, an order-reduction optimal control strategy was proposed under multi-device open-circuit fault to realize fault-tolerant control based on the topology and control requirement of ANPC three-level inverter and operation stability. This control strategy can solve the faults with different operation states, and can works in order-reduction state under specific open-circuit faults with specific combined devices, which sacrifices the control quality to obtain the stability priority control. Finally, the simulation and experiment proved the effectiveness of the proposed strategy.

  8. Effect of the depth base along the vertical on the electrical parameters of a vertical parallel silicon solar cell in open and short circuit

    Directory of Open Access Journals (Sweden)

    Gokhan Sahin

    2018-03-01

    Full Text Available This article presented a modeling study of effect of the depth base initiating on vertical parallel silicon solar cell’s photovoltaic conversion efficiency. After the resolution of the continuity equation of excess minority carriers, we calculated the electrical parameters such as the photocurrent density, the photovoltage, series resistance and shunt resistances, diffusion capacitance, electric power, fill factor and the photovoltaic conversion efficiency. We determined the maximum electric power, the operating point of the solar cell and photovoltaic conversion efficiency according to the depth z in the base. We showed that the photocurrent density decreases with the depth z. The photovoltage decreased when the depth base increases. Series and shunt resistances were deduced from electrical model and were influenced and the applied the depth base. The capacity decreased with the depth z of the base. We had studied the influence of the variation of the depth z on the electrical parameters in the base. Keywords: Depth base, Conversion efficiency, Electrical parameters, Open circuit, Short circuit

  9. Re-evaluating the role of sterics and electronic coupling in determining the open-circuit voltage of organic solar cells

    KAUST Repository

    Graham, Kenneth; Erwin, Patrick; Nordlund, Dennis; Vandewal, Koen; Li, Ruipeng; Ngongang Ndjawa, Guy Olivier; Hoke, Eric T.; Salleo, Alberto; Thompson, Mark E.; McGehee, Michael D.; Amassian, Aram

    2013-01-01

    The effects of sterics and molecular orientation on the open-circuit voltage and absorbance properties of charge-transfer states are explored in model bilayer organic photovoltaics. It is shown that the open-circuit voltage correlates linearly with the charge-transfer state energy and is not significantly influenced by electronic coupling. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Re-evaluating the role of sterics and electronic coupling in determining the open-circuit voltage of organic solar cells

    KAUST Repository

    Graham, Kenneth

    2013-07-30

    The effects of sterics and molecular orientation on the open-circuit voltage and absorbance properties of charge-transfer states are explored in model bilayer organic photovoltaics. It is shown that the open-circuit voltage correlates linearly with the charge-transfer state energy and is not significantly influenced by electronic coupling. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Online model-based estimation of state-of-charge and open-circuit voltage of lithium-ion batteries in electric vehicles

    International Nuclear Information System (INIS)

    He, Hongwen; Zhang, Xiaowei; Xiong, Rui; Xu, Yongli; Guo, Hongqiang

    2012-01-01

    This paper presents a method to estimate the state-of-charge (SOC) of a lithium-ion battery, based on an online identification of its open-circuit voltage (OCV), according to the battery’s intrinsic relationship between the SOC and the OCV for application in electric vehicles. Firstly an equivalent circuit model with n RC networks is employed modeling the polarization characteristic and the dynamic behavior of the lithium-ion battery, the corresponding equations are built to describe its electric behavior and a recursive function is deduced for the online identification of the OCV, which is implemented by a recursive least squares (RLS) algorithm with an optimal forgetting factor. The models with different RC networks are evaluated based on the terminal voltage comparisons between the model-based simulation and the experiment. Then the OCV-SOC lookup table is built based on the experimental data performed by a linear interpolation of the battery voltages at the same SOC during two consecutive discharge and charge cycles. Finally a verifying experiment is carried out based on nine Urban Dynamometer Driving Schedules. It indicates that the proposed method can ensure an acceptable accuracy of SOC estimation for online application with a maximum error being less than 5.0%. -- Highlights: ► An equivalent circuit model with n RC networks is built for lithium-ion batteries. ► A recursive function is deduced for the online estimation of the model parameters like OCV and R O . ► The relationship between SOC and OCV is built with a linear interpolation method by experiments. ► The experiments show the online model-based SOC estimation is reasonable with enough accuracy.

  12. Correlation between LUMO offset of donor/acceptor molecules to an open circuit voltage in bulk heterojunction solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Mola, Genene Tessema, E-mail: mola@ukzn.ac.za [School of. Chemistry and Physics, University of Kwazulu-Natal, Pietermaritzburg Campus, Private Bag X01, Scottsville 3209 (South Africa); Abera, Newayemedhin [Addis Ababa University, Department of Physics, P.O. BOX 1176, Addis Ababa (Ethiopia)

    2014-07-15

    The correlation between the open circuit voltage and the LUMO offset of the donor and acceptor polymers in the bulkheterojunction solar cell was studied for three different thiophene derivatives. The HOMO levels of all the polymers in this investigation were chosen to be similar which results in close values of ΔE{sub DA}=E{sub HOMO}{sup D}−E{sub LUMO}{sup A}. However, the measured V{sub oc} was found to be increasing with decreasing value of the LUMO offset that exists between the donor polymer and fullerene.

  13. Matlab/Simulink Implementation of Wave-based Models for Microstrip Structures utilizing Short-circuited and Opened Stubs

    Directory of Open Access Journals (Sweden)

    Biljana P. Stošić

    2011-12-01

    Full Text Available This paper describes modeling and analyzing procedures for microstrip filters based on use of one-dimensional wave digital approach. Different filter structures are observed. One filter is based on quarter-wave length short-circuited stubs and connecting transmission lines. The other one is based on cross-junction opened stubs. Frequency responses are obtained by direct analysis of the block-based networks formed in Simulink toolbox of MATLAB environment. This wave-based method allows an accurate and efficient analysis of different microwave structures.

  14. Coupling Spatial Segregation with Synthetic Circuits to Control Bacterial Survival (Open Access)

    Science.gov (United States)

    2016-02-29

    gated by encapsulation ( APA membrane), we developed a full model, specific for the BlaM circuit to account for the essential reac- tions involved in...L-lysine)-alginate ( APA ) microcapsules containing bacterial cells were fabricated by a soft lithography technique (Duffy et al, 1998). The...HB, Kolter R (2000) BIOFILM FORMATION AS MICROBIAL DEVELOPMENT. Annu Rev Microbiol 54: 49 – 79 Pai A, You L (2009) Optimal tuning of bacterial sensing

  15. Interface band gap narrowing behind open circuit voltage losses in Cu2ZnSnS4 solar cells

    DEFF Research Database (Denmark)

    Crovetto, Andrea; Palsgaard, Mattias Lau Nøhr; Gunst, Tue

    2017-01-01

    We present evidence that bandgap narrowing at the heterointerface may be a major cause of the large open circuit voltage deficit of Cu2ZnSnS4/CdS solar cells. Bandgap narrowing is caused by surface states that extend the Cu2ZnSnS4valence band into the forbidden gap. Those surface states...... are consistently found in Cu2ZnSnS4, but not in Cu2ZnSnSe4, by first-principles calculations. They do not simply arise from defects at surfaces but are an intrinsic feature of Cu2ZnSnS4 surfaces. By including those states in a device model, the outcome of previously published temperature-dependent open circuit...... voltage measurements on Cu2ZnSnS4 solar cells can be reproduced quantitatively without necessarily assuming a cliff-like conduction band offset with the CdS buffer layer. Our first-principles calculations indicate that Zn-based alternative buffer layers are advantageous due to the ability of...

  16. Development of Thin Film Amorphous Silicon Tandem Junction Based Photocathodes Providing High Open-Circuit Voltages for Hydrogen Production

    Directory of Open Access Journals (Sweden)

    F. Urbain

    2014-01-01

    Full Text Available Hydrogenated amorphous silicon thin film tandem solar cells (a-Si:H/a-Si:H have been developed with focus on high open-circuit voltages for the direct application as photocathodes in photoelectrochemical water splitting devices. By temperature variation during deposition of the intrinsic a-Si:H absorber layers the band gap energy of a-Si:H absorber layers, correlating with the hydrogen content of the material, can be adjusted and combined in a way that a-Si:H/a-Si:H tandem solar cells provide open-circuit voltages up to 1.87 V. The applicability of the tandem solar cells as photocathodes was investigated in a photoelectrochemical cell (PEC measurement set-up. With platinum as a catalyst, the a-Si:H/a-Si:H based photocathodes exhibit a high photocurrent onset potential of 1.76 V versus the reversible hydrogen electrode (RHE and a photocurrent of 5.3 mA/cm2 at 0 V versus RHE (under halogen lamp illumination. Our results provide evidence that a direct application of thin film silicon based photocathodes fulfills the main thermodynamic requirements to generate hydrogen. Furthermore, the presented approach may provide an efficient and low-cost route to solar hydrogen production.

  17. Prediction Model and Principle of End-of-Life Threshold for Lithium Ion Batteries Based on Open Circuit Voltage Drifts

    International Nuclear Information System (INIS)

    Cui, Yingzhi; Yang, Jie; Du, Chunyu; Zuo, Pengjian; Gao, Yunzhi; Cheng, Xinqun; Ma, Yulin; Yin, Geping

    2017-01-01

    Highlights: •Open circuit voltage evolution over ageing of lithium ion batteries is deciphered. •The mechanism responsible for the end-of-life (EOL) threshold is elaborated. •A new prediction model of EOL threshold with improved accuracy is developed. •This EOL prediction model is promising for the applications in electric vehicles. -- Abstract: The end-of-life (EOL) of a lithium ion battery (LIB) is defined as the time point when the LIB can no longer provide sufficient power or energy to accomplish its intended function. Generally, the EOL occurs abruptly when the degradation of a LIB reaches the threshold. Therefore, current prediction methods of EOL by extrapolating the early degradation behavior often result in significant errors. To address this problem, this paper analyzes the reason for the EOL threshold of a LIB with shallow depth of discharge. It is found that the sudden appearance of EOL threshold results from the drift of open circuit voltage (OCV) at the end of both shallow depth and full discharges. Further, a new EOL threshold prediction model with highly improved accuracy is developed based on the OCV drifts and their evolution mechanism, which can effectively avoid the misjudgment of EOL threshold. The accuracy of this EOL threshold prediction model is verified by comparing with experimental results. The EOL threshold prediction model can be applied to other battery chemistry systems and its possible application in electric vehicles is finally discussed.

  18. Long-Term Planning for Open Pits for Mining Sulphide-Oxide Ores in Order to Achieve Maximum Profit

    Science.gov (United States)

    Kržanović, Daniel; Conić, Vesna; Stevanović, Dejan; Kolonja, Božo; Vaduvesković, Jovan

    2017-12-01

    Profitable exploitation of mineralised material from the earth's crust is a complex and difficult task that depends on a comprehensive planning process. Answering the question of how to plan production depends on the geometry of the deposit, as well as the concentration, distribution, and type of minerals in it. The complex nature of mineral deposits largely determines the method of exploitation and profitability of mining operations. In addition to unit operating costs and metal prices, the optimal recovery of and achievement of maximum profit from deposits of sulphide-oxide ores also depend, to a significant extent, on the level of technological recovery achieved in the ore processing procedure. Therefore, in defining a long-term development strategy for open pits, special attention must be paid to the selection of an optimal procedure for ore processing in order to achieve the main objective: maximising the Net Present Value (NPV). The effect of using two different processes, flotation processing and hydrometallurgical methods (bioleaching acid leaching), on determining the ultimate pit is shown in the case of the Kraku Bugaresku-Cementacija sulphide-oxide ore deposit in eastern Serbia. Analysis shows that the application of hydrometallurgical methods of processing sulphide-oxide ore achieved an increase in NPV of 20.42%.

  19. Monitoring of incremental changes in maximum interincisal opening after gap arthroplasty omits the risk of Re-ankylosis.

    Science.gov (United States)

    Khalifa, Ghada Amin

    2018-01-01

    The aim of this clinical study was to prospectively measure the incremental changes in the maximum interincisal opening (MIO) after 1 cm gap arthroplasty, compare these changes between unilateral and bilateral cases, and emphasize the importance of the monitoring of the MIO for at least 24 months. This prospective study enrolled 26 patients with TMJ ankylosis either unilateral or bilateral. The fingers assessment method was used to measure the MIO preoperatively, intraoperatively, and monthly postoperatively up to 24 months. All the patients had undergone 1 cm gap arthroplasty to release the ankylosis. The changes in MIO measurements of unilateral and bilateral cases were statistically compared. The physiotherapy was performed until the measurements had normal stable values. All the cases showed a significant decrease in MIO at the first three months. At 6 months, the MIO continuously increased up to 1 year. There was no difference between the unilateral and bilateral cases. At the end of the follow-up, all measurements showed normal stable values. The monitoring of MIO is important to detect the early signs of re-ankylosis. It is the only way that can be used in which the early signs cannot be detected in radiographs. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  20. Commutation circuit for an HVDC circuit breaker

    Science.gov (United States)

    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.

  1. Open-Circuit End Effect of Microstrip Line Configuration in Plasma Medium

    Directory of Open Access Journals (Sweden)

    Prem Bhushan Mital

    1996-01-01

    Full Text Available The extension in length for open microstrip configuration in plasma media is determined using spectral domain technique under quasi static approach [1, 2]. The results were verified by modifying Hammerstad equation for plasma media. Good agreement is found between the two results.

  2. The importance of band tail recombination on current collection and open-circuit voltage in CZTSSe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Moore, James E. [Naval Research Laboratory, Washington, DC 20375 (United States); Purdue University, West Lafayette, Indiana 47907 (United States); Hages, Charles J. [Purdue University, West Lafayette, Indiana 47907 (United States); Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Agrawal, Rakesh; Lundstrom, Mark S.; Gray, Jeffery L. [Purdue University, West Lafayette, Indiana 47907 (United States)

    2016-07-11

    Cu{sub 2}ZnSn(S,Se){sub 4} (CZTSSe) solar cells typically exhibit high short-circuit current density (J{sub sc}), but have reduced cell efficiencies relative to other thin film technologies due to a deficit in the open-circuit voltage (V{sub oc}), which prevent these devices from becoming commercially competitive. Recent research has attributed the low V{sub oc} in CZTSSe devices to small scale disorder that creates band tail states within the absorber band gap, but the physical processes responsible for this V{sub oc} reduction have not been elucidated. In this paper, we show that carrier recombination through non-mobile band tail states has a strong voltage dependence and is a significant performance-limiting factor, and including these effects in simulation allows us to simultaneously explain the V{sub oc} deficit, reduced fill factor, and voltage-dependent quantum efficiency with a self-consistent set of material parameters. Comparisons of numerical simulations to measured data show that reasonable values for the band tail parameters (characteristic energy, capture rate) can account for the observed low V{sub oc}, high J{sub sc}, and voltage dependent collection efficiency. These results provide additional evidence that the presence of band tail states accounts for the low efficiencies of CZTSSe solar cells and further demonstrates that recombination through non-mobile band tail states is the dominant efficiency limiting mechanism.

  3. Comparative Study of Online Open Circuit Voltage Estimation Techniques for State of Charge Estimation of Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Hicham Chaoui

    2017-04-01

    Full Text Available Online estimation techniques are extensively used to determine the parameters of various uncertain dynamic systems. In this paper, online estimation of the open-circuit voltage (OCV of lithium-ion batteries is proposed by two different adaptive filtering methods (i.e., recursive least square, RLS, and least mean square, LMS, along with an adaptive observer. The proposed techniques use the battery’s terminal voltage and current to estimate the OCV, which is correlated to the state of charge (SOC. Experimental results highlight the effectiveness of the proposed methods in online estimation at different charge/discharge conditions and temperatures. The comparative study illustrates the advantages and limitations of each online estimation method.

  4. Detection of Two-Level Inverter Open-Circuit Fault Using a Combined DWT-NN Approach

    Directory of Open Access Journals (Sweden)

    Bilal Djamel Eddine Cherif

    2018-01-01

    Full Text Available Three-phase static converters with voltage structure are widely used in many industrial systems. In order to prevent the propagation of the fault to other components of the system and ensure continuity of service in the event of a failure of the converter, efficient and rapid methods of detection and localization must be implemented. This paper work addresses a diagnostic technique based on the discrete wavelet transform (DWT algorithm and the approach of neural network (NN, for the detection of an inverter IGBT open-circuit switch fault. To illustrate the merits of the technique and validate the results, experimental tests are conducted using a built voltage inverter fed induction motor. The inverter is controlled by the SVM control strategy.

  5. Enhanced Open-Circuit Voltage in Colloidal Quantum Dot Photovoltaics via Reactivity-Controlled Solution-Phase Ligand Exchange

    KAUST Repository

    Jo, Jea Woong; Kim, Younghoon; Choi, Jongmin; de Arquer, F. Pelayo Garcí a; Walters, Grant; Sun, Bin; Ouellette, Olivier; Kim, Junghwan; Proppe, Andrew H.; Quintero-Bermudez, Rafael; Fan, James; Xu, Jixian; Tan, Chih Shan; Voznyy, Oleksandr; Sargent, Edward H.

    2017-01-01

    The energy disorder that arises from colloidal quantum dot (CQD) polydispersity limits the open-circuit voltage (VOC) and efficiency of CQD photovoltaics. This energy broadening is significantly deteriorated today during CQD ligand exchange and film assembly. Here, a new solution-phase ligand exchange that, via judicious incorporation of reactivity-engineered additives, provides improved monodispersity in final CQD films is reported. It has been found that increasing the concentration of the less reactive species prevents CQD fusion and etching. As a result, CQD solar cells with a VOC of 0.7 V (vs 0.61 V for the control) for CQD films with exciton peak at 1.28 eV and a power conversion efficiency of 10.9% (vs 10.1% for the control) is achieved.

  6. Enhanced Open-Circuit Voltage in Colloidal Quantum Dot Photovoltaics via Reactivity-Controlled Solution-Phase Ligand Exchange

    KAUST Repository

    Jo, Jea Woong

    2017-10-09

    The energy disorder that arises from colloidal quantum dot (CQD) polydispersity limits the open-circuit voltage (VOC) and efficiency of CQD photovoltaics. This energy broadening is significantly deteriorated today during CQD ligand exchange and film assembly. Here, a new solution-phase ligand exchange that, via judicious incorporation of reactivity-engineered additives, provides improved monodispersity in final CQD films is reported. It has been found that increasing the concentration of the less reactive species prevents CQD fusion and etching. As a result, CQD solar cells with a VOC of 0.7 V (vs 0.61 V for the control) for CQD films with exciton peak at 1.28 eV and a power conversion efficiency of 10.9% (vs 10.1% for the control) is achieved.

  7. Study on Factors for Accurate Open Circuit Voltage Characterizations in Mn-Type Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Natthawuth Somakettarin

    2017-03-01

    Full Text Available Open circuit voltage (OCV of lithium batteries has been of interest since the battery management system (BMS requires an accurate knowledge of the voltage characteristics of any Li-ion batteries. This article presents an OCV characteristic for lithium manganese oxide (LMO batteries under several experimental operating conditions, and discusses factors for accurate OCV determination. A test system is developed for OCV characterization based on the OCV pulse test method. Various factors for the OCV behavior, such as resting period, step-size of the pulse test, testing current amplitude, hysteresis phenomena, and terminal voltage relationship, are investigated and evaluated. To this end, a general OCV model based on state of charge (SOC tracking is developed and validated with satisfactory results.

  8. Microstructural and Electronic Origins of Open-Circuit Voltage Tuning in Organic Solar Cells Based on Ternary Blends

    KAUST Repository

    Mollinger, Sonya A.

    2015-09-22

    © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Organic ternary heterojunction photovoltaic blends are sometimes observed to undergo a gradual evolution in open-circuit voltage (Voc) with increasing amounts of a second donor or an acceptor. The Voc is strongly correlated with the energy of the charge transfer state in the blend, but this value depends on both local and mesoscopic orders. In this work, the behavior of Voc in the presence of a wide range of interfacial electronic states is investigated. The key charge transfer state interfaces responsible for Voc in several model systems with varying morphology are identified. Systems consisting of one donor with two fullerene molecules and of one acceptor with a donor polymer of varying regio-regularity are used. The effects from the changing energetic disorder in the material and from the variation due to a law of simple mixtures are quantified. It has been found that populating the higher-energy charge transfer states is not responsible for the observed change in Voc upon the addition of a third component. Aggregating polymers and miscible fullerenes are compared, and it has been concluded that in both cases charge delocalization, aggregation, and local polarization effects shift the lowest-energy charge transfer state distribution. The open-circuit voltage evolution and charge transfer state interfaces in ternary organic photovoltaic blends are investigated using several model systems. The changes in subgap spectra from energetic disorder and increased population of higher energy states are analyzed and the lowest charge transfer state distribution is observed to shift due to local aggregation and delocalization effects.

  9. Influence of different open circuit voltage tests on state of charge online estimation for lithium-ion batteries

    International Nuclear Information System (INIS)

    Zheng, Fangdan; Xing, Yinjiao; Jiang, Jiuchun; Sun, Bingxiang; Kim, Jonghoon; Pecht, Michael

    2016-01-01

    Highlights: • Two common tests for observing battery open circuit voltage performance are compared. • The temperature dependency of the OCV-SOC relationship is investigated. • Two estimators are evaluated in terms of accuracy and robustness for estimating battery SOC. • The incremental OCV test is better to predetermine the OCV-SOCs for SOC online estimation. - Abstract: Battery state of charge (SOC) estimation is a crucial function of battery management systems (BMSs), since accurate estimated SOC is critical to ensure the safety and reliability of electric vehicles. A widely used technique for SOC estimation is based on online inference of battery open circuit voltage (OCV). Low-current OCV and incremental OCV tests are two common methods to observe the OCV-SOC relationship, which is an important element of the SOC estimation technique. In this paper, two OCV tests are run at three different temperatures and based on which, two SOC estimators are compared and evaluated in terms of tracking accuracy, convergence time, and robustness for online estimating battery SOC. The temperature dependency of the OCV-SOC relationship is investigated and its influence on SOC estimation results is discussed. In addition, four dynamic tests are presented, one for estimator parameter identification and the other three for estimator performance evaluation. The comparison results show that estimator 2 (based on the incremental OCV test) has higher tracking accuracy and is more robust against varied loading conditions and different initial values of SOC than estimator 1 (based on the low-current OCV test) with regard to ambient temperature. Therefore, the incremental OCV test is recommended for predetermining the OCV-SOCs for battery SOC online estimation in BMSs.

  10. Microstructural and Electronic Origins of Open-Circuit Voltage Tuning in Organic Solar Cells Based on Ternary Blends

    KAUST Repository

    Mollinger, Sonya A.; Vandewal, Koen; Salleo, Alberto

    2015-01-01

    © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Organic ternary heterojunction photovoltaic blends are sometimes observed to undergo a gradual evolution in open-circuit voltage (Voc) with increasing amounts of a second donor or an acceptor. The Voc is strongly correlated with the energy of the charge transfer state in the blend, but this value depends on both local and mesoscopic orders. In this work, the behavior of Voc in the presence of a wide range of interfacial electronic states is investigated. The key charge transfer state interfaces responsible for Voc in several model systems with varying morphology are identified. Systems consisting of one donor with two fullerene molecules and of one acceptor with a donor polymer of varying regio-regularity are used. The effects from the changing energetic disorder in the material and from the variation due to a law of simple mixtures are quantified. It has been found that populating the higher-energy charge transfer states is not responsible for the observed change in Voc upon the addition of a third component. Aggregating polymers and miscible fullerenes are compared, and it has been concluded that in both cases charge delocalization, aggregation, and local polarization effects shift the lowest-energy charge transfer state distribution. The open-circuit voltage evolution and charge transfer state interfaces in ternary organic photovoltaic blends are investigated using several model systems. The changes in subgap spectra from energetic disorder and increased population of higher energy states are analyzed and the lowest charge transfer state distribution is observed to shift due to local aggregation and delocalization effects.

  11. Tessellated permanent magnet circuits for flow-through, open gradient separations of weakly magnetic materials

    International Nuclear Information System (INIS)

    Moore, Lee R.; Williams, P. Stephen; Chalmers, Jeffrey J.; Zborowski, Maciej

    2017-01-01

    Emerging microfluidic-based cell assays favor label-free red blood cell (RBC) depletion. Magnetic separation of RBC is possible because of the paramagnetism of deoxygenated hemoglobin but the process is slow for open-gradient field configurations. In order to increase the throughput, periodic arrangements of the unit magnets were considered, consisting of commercially available Nd-Fe-B permanent magnets and soft steel flux return pieces. The magnet design is uniquely suitable for multiplexing by magnet tessellation, here meaning the tiling of the magnet assembly cross-sectional plane by periodic repetition of the magnet and the flow channel shapes. The periodic pattern of magnet magnetizations allows a reduction of the magnetic material per channel with minimal distortion of the field cylindrical symmetry inside the magnet apertures. A number of such magnet patterns are investigated for separator performance, size and economy with the goal of designing an open-gradient magnetic separator capable of reducing the RBC number concentration a hundred-fold in 1 mL whole blood per hour. - Highlights: • Simple geometry of commercial, off-the-shelf NdFeB magnet blocks is amenable to generate high fields and open gradients. • Periodic pattern of permanent magnet blocks (tessellation) reduces the number of blocks per separation channel and improves the efficiency of separator design. • Split-flow lateral transport thin (SPLITT) fractionation model predicts 100-fold reduction of red blood cells from 1 mL whole blood sample in 1 h, suitable for laboratory medicine applications.

  12. Tessellated permanent magnet circuits for flow-through, open gradient separations of weakly magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Lee R. [Department of Biomedical Engineering, Cleveland Clinic, 9500 Euclid Ave., Cleveland OH 44195 (United States); Williams, P. Stephen [Cambrian Technologies, Inc., Cleveland, OH (United States); Chalmers, Jeffrey J. [William G. Lowrie Department of Chemical and Biomedical Engineering, The Ohio State University, Columbus 151 W. Woodruff Avenue, OH 43210 (United States); Zborowski, Maciej, E-mail: zborowm@ccf.org [Department of Biomedical Engineering, Cleveland Clinic, 9500 Euclid Ave., Cleveland OH 44195 (United States)

    2017-04-01

    Emerging microfluidic-based cell assays favor label-free red blood cell (RBC) depletion. Magnetic separation of RBC is possible because of the paramagnetism of deoxygenated hemoglobin but the process is slow for open-gradient field configurations. In order to increase the throughput, periodic arrangements of the unit magnets were considered, consisting of commercially available Nd-Fe-B permanent magnets and soft steel flux return pieces. The magnet design is uniquely suitable for multiplexing by magnet tessellation, here meaning the tiling of the magnet assembly cross-sectional plane by periodic repetition of the magnet and the flow channel shapes. The periodic pattern of magnet magnetizations allows a reduction of the magnetic material per channel with minimal distortion of the field cylindrical symmetry inside the magnet apertures. A number of such magnet patterns are investigated for separator performance, size and economy with the goal of designing an open-gradient magnetic separator capable of reducing the RBC number concentration a hundred-fold in 1 mL whole blood per hour. - Highlights: • Simple geometry of commercial, off-the-shelf NdFeB magnet blocks is amenable to generate high fields and open gradients. • Periodic pattern of permanent magnet blocks (tessellation) reduces the number of blocks per separation channel and improves the efficiency of separator design. • Split-flow lateral transport thin (SPLITT) fractionation model predicts 100-fold reduction of red blood cells from 1 mL whole blood sample in 1 h, suitable for laboratory medicine applications.

  13. Open-Circuit Voltage in Organic Solar Cells: The Impacts of Donor Semicrystallinity and Coexistence of Multiple Interfacial Charge-Transfer Bands

    KAUST Repository

    Ngongang Ndjawa, Guy Olivier; Graham, Kenneth; Mollinger, Sonya; Wu, Di M.; Hanifi, David; Prasanna, Rohit; Rose, Bradley Daniel; Dey, Sukumar; Yu, Liyang; Bredas, Jean-Luc; McGehee, Michael D.; Salleo, Alberto; Amassian, Aram

    2017-01-01

    In organic solar cells (OSCs), the energy of the charge-transfer (CT) complexes at the donor-acceptor interface, E , determines the maximum open-circuit voltage (V ). The coexistence of phases with different degrees of order in the donor or the acceptor, as in blends of semi-crystalline donors and fullerenes in bulk heterojunction layers, influences the distribution of CT states and the V enormously. Yet, the question of how structural heterogeneities alter CT states and the V is seldom addressed systematically. In this work, we combine experimental measurements of vacuum-deposited rubrene/C bilayer OSCs, with varying microstructure and texture, with density functional theory calculations to determine how relative molecular orientations and extents of structural order influence E and V . We find that varying the microstructure of rubrene gives rise to CT bands with varying energies. The CT band that originates from crystalline rubrene lies up to ≈0.4 eV lower in energy compared to the one that arises from amorphous rubrene. These low-lying CT states contribute strongly to V losses and result mainly from hole delocalization in aggregated rubrene. This work points to the importance of realizing interfacial structural control that prevents the formation of low E configurations and maximizes V .

  14. Simultaneous Increase in Open-Circuit Voltage and Efficiency of Fullerene-Free Solar Cells through Chlorinated Thieno[3,4- b ]thiophene Polymer Donor

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huan [Department; Chao, Pengjie [Department; Chen, Hui [Department; Mu, Zhao [Department; Chen, Wei [Materials; Institute; He, Feng [Department

    2017-08-09

    The chlorinated polymer, PBTCl, has been found to be an efficient donor in nonfullerene polymer solar cells (PSCs), which showed a blue-shifted absorbance compared to that of its fluorine analogue (PTB7-th) and resulted in more complementary light absorption with a nonfullerene acceptor, such as ITIC. Meanwhile, chlorine substitution lowered the HOMO level of PBTCl, which increased the open-circuit voltage of the corresponding polymer-based devices. The 2D GIWAXS analysis illustrated that the PBTCl/ITIC blend film exhibited a “face-on” orientation and scattering features of both PBTCl and ITIC, suggesting that the blend of PBTCl and ITIC was phase-separated and formed individual crystalline domains of the donor and acceptor, which promoted charge transfer in the bicontinuous film and eventually elevated the solar energy conversion efficiency. The PBTCl-based nonfullerene PSC exhibited a maximum PCE of 7.57% with a Voc of 0.91 V, which was an approximately 13% increasing in the PCE compared to that of the fluorine-analogue-based device.

  15. Open-Circuit Voltage in Organic Solar Cells: The Impacts of Donor Semicrystallinity and Coexistence of Multiple Interfacial Charge-Transfer Bands

    KAUST Repository

    Ngongang Ndjawa, Guy Olivier

    2017-01-16

    In organic solar cells (OSCs), the energy of the charge-transfer (CT) complexes at the donor-acceptor interface, E , determines the maximum open-circuit voltage (V ). The coexistence of phases with different degrees of order in the donor or the acceptor, as in blends of semi-crystalline donors and fullerenes in bulk heterojunction layers, influences the distribution of CT states and the V enormously. Yet, the question of how structural heterogeneities alter CT states and the V is seldom addressed systematically. In this work, we combine experimental measurements of vacuum-deposited rubrene/C bilayer OSCs, with varying microstructure and texture, with density functional theory calculations to determine how relative molecular orientations and extents of structural order influence E and V . We find that varying the microstructure of rubrene gives rise to CT bands with varying energies. The CT band that originates from crystalline rubrene lies up to ≈0.4 eV lower in energy compared to the one that arises from amorphous rubrene. These low-lying CT states contribute strongly to V losses and result mainly from hole delocalization in aggregated rubrene. This work points to the importance of realizing interfacial structural control that prevents the formation of low E configurations and maximizes V .

  16. Leakage Current Induced by Energetic Disorder in Organic Bulk Heterojunction Solar Cells: Comprehending the Ultrahigh Loss of Open-Circuit Voltage at Low Temperatures

    Science.gov (United States)

    Yang, Wenchao; Luo, Yongsong; Guo, Pengfei; Sun, Haibin; Yao, Yao

    2017-04-01

    The open-circuit voltage (Voc ) of organic solar cells generally approaches its maximum obtainable values as the temperature decreases. However, recent experiments have revealed that the Voc may suffer from an ultrahigh loss at low temperatures. In order to verify this explanation and investigate the impacts of energetic disorder on the temperature-dependent behaviors of the Voc in general, we calculate the Voc-T plots with the drift-diffusion method under various device working parameters. With the disorder being incorporated into the device model by considering the disorder-suppressed (temperature-dependent) charge-carrier mobilities, it is found that the ultrahigh Voc losses cannot be reproduced under the Onsager-Braun-type charge generation rate. With the charge generation rate being constant or weakly dependent on temperature, for nonselective contacts, the Voc reduces drastically at low temperatures, while for selective contacts, the Voc increases monotonically with decreasing temperature. With higher carrier mobilities or smaller device thicknesses, the ultrahigh loss occurs at lower temperatures. The mechanism is that, since the disorder-suppressed charge mobilities give rise to both low charge-extraction efficiency and small bimolecular recombination rate, plenty of charge carriers can be extracted from the wrong electrode and can form a large leakage current, which counteracts the majority-carrier current and reduces the Voc at low temperatures. Our results thus highlight the essential role of charge-carrier kinetics, except for the charge-filling effect, on dominating the disorder-induced Voc losses.

  17. Formation of a p-n heterojunction on GaP photocathodes for H-2 production providing an open-circuit voltage of 710 mV

    DEFF Research Database (Denmark)

    Malizia, Mauro; Seger, Brian; Chorkendorff, Ib

    2014-01-01

    Photocatalytic water splitting for the sustainable production of hydrogen using a two-photon tandem device requires careful optimization of the semiconductors used as photon absorbers. In this work we show how the open-circuit voltage of photocathodes for the hydrogen evolution reaction based on ...

  18. Current Matching in Multifold DBP/C70 Organic Solar Cells With Open-Circuit Voltages of up to 6.44 V

    DEFF Research Database (Denmark)

    Ahmadpour, Mehrad; Liu, Yiming; Rubahn, Horst-Günter

    2017-01-01

    In this paper, we demonstrate a novel method for achieving high open-circuit voltages (Voc) in organic solar cells based on tetraphenyldibenzoperiflanthen (DBP) as donor and fullerene (C70) as acceptor molecules, by fabrication of multifold bilayer single cells stacked on top of each other...

  19. Numerical Study on Open-Circuit Voltage of Single Layer Organic Solar Cells with Schottky Contacts: Effects of Molecular Energy Levels, Temperature and Thickness

    International Nuclear Information System (INIS)

    Rong-Hua, Li; Ying-Quan, Peng; Chao-Zhu, Ma; Run-Sheng, Wang; Hong-Wei, Xie; Ying, Wang; Wei-Min, Meng

    2010-01-01

    We numerically investigate the effects of the exciton generation rate G, temperature T, the active layer thickness d and the position of LUMO level E L related to the cathode work function W c at a given energy gap on the open-circuit voltage V oc of single layer organic solar cells with Schottky contact. It is demonstrated that open-circuit voltage increases concomitantly with the decreasing cathode work function W c for given anode work functions and exciton generation rates. In the case of given cathode and anode work functions, the open-circuit voltage first increases with the exciton generation rate and then reaches a saturation value, which equals to the built-in voltage. Additionally, it is worth noting that a significant improvement to V oc could be made by selecting an organic material which has a relative high LUMO level (low |E L | value). However, V oc decreases as the temperature increases, and the decreasing rate reduces with the enhancement of exciton generation rate. Our study also shows that it is of no benefit to improve the open-circuit voltage by increasing the device thickness because of an enhanced charge recombination in thicker devices. (cross-disciplinary physics and related areas of science and technology)

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

    KAUST Repository

    Ko, Sangwon; Hoke, Eric T.; Pandey, Laxman; Hong, Sanghyun; Mondal, Rajib; Risko, Chad; Yi, Yuanping; Noriega, Rodrigo; McGehee, Michael D.; Bré das, Jean-Luc; Salleo, Alberto; Bao, Zhenan

    2012-01-01

    and charge-transfer state energy of the polymer:fullerene BHJ solar cells increased substantially with the degree of twist induced within the conjugated backbone-due to an increase in the polymer ionization potential-while the short-circuit current decreased

  1. Photoelectrochemical Complexes of Fucoxanthin-Chlorophyll Protein for Bio-Photovoltaic Conversion with a High Open-Circuit Photovoltage.

    Science.gov (United States)

    Zhang, Tianning; Liu, Cheng; Dong, Wenjing; Wang, Wenda; Sun, Yan; Chen, Xin; Yang, Chunhong; Dai, Ning

    2017-12-05

    Open-circuit photovoltage (V oc ) is among the critical parameters for achieving an efficient light-to-charge conversion in existing solar photovoltaic devices. Natural photosynthesis exploits light-harvesting chlorophyll (Chl) protein complexes to transfer sunlight energy efficiently. We describe the exploitation of photosynthetic fucoxanthin-chlorophyll protein (FCP) complexes for realizing photoelectrochemical cells with a high V oc . An antenna-dependent photocurrent response and a V oc up to 0.72 V are observed and demonstrated in the bio-photovoltaic devices fabricated with photosynthetic FCP complexes and TiO 2 nanostructures. Such high V oc is determined by fucoxanthin in FCP complexes, and is rarely found in photoelectrochemical cells with other natural light-harvesting antenna. We think that the FCP-based bio-photovoltaic conversion will provide an opportunity to fabricate environmental benign photoelectrochemical cells with high V oc , and also help improve the understanding of the essential physics behind the light-to-charge conversion in photosynthetic complexes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Molecular design of novel fullerene-based acceptors for enhancing the open circuit voltage in polymer solar cells

    Science.gov (United States)

    Tajbakhsh, Mahmood; Kariminasab, Mohaddeseh; Ganji, Masoud Darvish; Alinezhad, Heshmatollah

    2017-12-01

    Organic solar cells, especially bulk hetero-junction polymer solar cells (PSCs), are the most successful structures for applications in renewable energy. The dramatic improvement in the performance of PSCs has increased demand for new conjugated polymer donors and fullerene derivative acceptors. In the present study, quantum chemical calculations were performed for several representative fullerene derivatives in order to determine their frontier orbital energy levels and electronic structures, thereby helping to enhance their performance in PSC devices. We found correlations between the theoretical lowest unoccupied molecular orbital levels and electrophilicity index of various fullerenes with the experimental open circuit voltage of photovoltaic devices according to the poly(3-hexylthiophene) (P3HT):fullerene blend. The correlations between the structure and descriptors may facilitate screening of the best fullerene acceptor for the P3HT donor. Thus, we considered fullerenes with new functional groups and we predicted the output factors for the corresponding P3HT:fullerene blend devices. The results showed that fullerene derivatives based on thieno-o-quinodimethane-C60 with a methoxy group will have enhanced photovoltaic properties. Our results may facilitate the design of new fullerenes and the development of favorable acceptors for use in photovoltaic applications.

  3. Recombination in polymer:Fullerene solar cells with open-circuit voltages approaching and exceeding 1.0 V

    KAUST Repository

    Hoke, Eric T.

    2012-09-14

    Polymer:fullerene solar cells are demonstrated with power conversion efficiencies over 7% with blends of PBDTTPD and PC 61 BM. These devices achieve open-circuit voltages ( V oc ) of 0.945 V and internal quantum efficiencies of 88%, making them an ideal candidate for the large bandgap junction in tandem solar cells. V oc \\'s above 1.0 V are obtained when the polymer is blended with multiadduct fullerenes; however, the photocurrent and fill factor are greatly reduced. In PBDTTPD blends with multiadduct fullerene ICBA, fullerene emission is observed in the photoluminescence and electroluminescence spectra, indicating that excitons are recombining on ICBA. Voltage-dependent, steady state and time-resolved photoluminescence measurements indicate that energy transfer occurs from PBDTTPD to ICBA and that back hole transfer from ICBA to PBDTTPD is inefficient. By analyzing the absorption and emission spectra from fullerene and charge transfer excitons, we estimate a driving free energy of -0.14 ± 0.06 eV is required for efficient hole transfer. These results suggest that the driving force for hole transfer may be too small for efficient current generation in polymer:fullerene solar cells with V oc values above 1.0 V and that non-fullerene acceptor materials with large optical gaps ( > 1.7 eV) may be required to achieve both near unity internal quantum efficiencies and values of V oc exceeding 1.0 V. © 2013 WILEY-VCH Verlag GmbH and Co.

  4. Study of the Contributions of Donor and Acceptor Photoexcitations to Open Circuit Voltage in Bulk Heterojunction Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    Douglas Yeboah

    2017-10-01

    Full Text Available One of the key parameters in determining the power conversion efficiency (PCE of bulk heterojunction (BHJ organic solar cells (OSCs is the open circuit voltage . The processes of exciting the donor and acceptor materials individually in a BHJ OSC are investigated and are found to produce two different expressions for . Using the contributions of electron and hole quasi-Fermi levels and charge carrier concentrations, the two different expressions are derived as functions of the energetics of the donor and acceptor materials and the photo-generated charge carrier concentrations, and calculated for a set of donor-acceptor blends. The simultaneous excitation of both the donor and acceptor materials is also considered and the corresponding , which is different from the above two, is derived. The calculated from the photoexcitation of the donor is found to be somewhat comparable with that obtained from the photoexcitation of the acceptor in most combinations of the donor and acceptor materials considered here. It is also found that the calculated from the simultaneous excitations of donor and acceptor in BHJ OSCs is also comparable with the other two . All three thus derived produce similar results and agree reasonably well with the measured values. All three depend linearly on the concentration of the photoexcited charge carriers and hence incident light intensity, which agrees with experimental results. The outcomes of this study are expected to help in finding materials that may produce higher and hence enhanced PCE in BHJ OSCs.

  5. Reduced voltage losses yield 10% efficient fullerene free organic solar cells with >1 V open circuit voltages

    KAUST Repository

    Baran, D.

    2016-11-09

    Optimization of the energy levels at the donor-acceptor interface of organic solar cells has driven their efficiencies to above 10%. However, further improvements towards efficiencies comparable with inorganic solar cells remain challenging because of high recombination losses, which empirically limit the open-circuit voltage (Voc) to typically less than 1 V. Here we show that this empirical limit can be overcome using non-fullerene acceptors blended with the low band gap polymer PffBT4T-2DT leading to efficiencies approaching 10% (9.95%). We achieve Voc up to 1.12 V, which corresponds to a loss of only Eg/q - Voc = 0.5 ± 0.01 V between the optical bandgap Eg of the polymer and Voc. This high Voc is shown to be associated with the achievement of remarkably low non-geminate and non-radiative recombination losses in these devices. Suppression of non-radiative recombination implies high external electroluminescence quantum efficiencies which are orders of magnitude higher than those of equivalent devices employing fullerene acceptors. Using the balance between reduced recombination losses and good photocurrent generation efficiencies achieved experimentally as a baseline for simulations of the efficiency potential of organic solar cells, we estimate that efficiencies of up to 20% are achievable if band gaps and fill factors are further optimized. © The Royal Society of Chemistry 2016.

  6. Modeling and interpretation of electrical impedance spectra of dye solar cells operated under open-circuit conditions

    International Nuclear Information System (INIS)

    Kern, R.; Sastrawan, R.; Ferber, J.; Stangl, R.; Luther, J.

    2002-01-01

    Electrical impedance spectroscopy (EIS) was applied in order to investigate electrochemical nanocrystalline TiO 2 dye solar cells (DSC). Typically, three characteristic frequency peaks were observed in the spectra. These frequency peaks could be explained by variations of cell parameters and by comparison with intensity-modulated photovoltage spectroscopy (IMVS). It was shown that the low-frequency peak (in the mHz range) corresponds to the Nernstian diffusion within the electrolyte, while the middle-frequency peak (in the 10-100 Hz range) reflects the properties of the photoinjected electrons within the TiO 2 . The high-frequency peak (in the kHz range) corresponds to the charge-transfer at the platinum counter electrode. For a detailed analysis of the spectra, a model was developed which allows the evaluation of EIS spectra, measured under bias illumination and under open-circuit conditions. The influence of cell parameters such as the TiO 2 layer thickness, cell thickness, charge-transfer resistance of the platinum counter electrode, and the lifetime of the photoinjected electrons, on the impedance spectra was studied both experimentally and theoretically. Finally, it is shown that EIS is a measurement method suited well for the investigation of the long-term stability of DSC, as changes of the inner cell parameters can be revealed

  7. Trifluoromethyl-Substituted Large Band-Gap Polytriphenylamines for Polymer Solar Cells with High Open-Circuit Voltages

    Directory of Open Access Journals (Sweden)

    Shuwang Yi

    2018-01-01

    Full Text Available Two large band-gap polymers (PTPACF and PTPA2CF based on polytriphenylamine derivatives with the introduction of electron-withdrawing trifluoromethyl groups were designed and prepared by Suzuki polycondensation reaction. The chemical structures, thermal, optical and electrochemical properties were characterized in detail. From the UV-visible absorption spectra, the PTPACF and PTPA2CF showed the optical band gaps of 2.01 and 2.07 eV, respectively. The cyclic voltammetry (CV measurement displayed the deep highest occupied molecular orbital (HOMO energy levels of −5.33 and −5.38 eV for PTPACF and PTPA2CF, respectively. The hole mobilities, determined by field-effect transistor characterization, were 2.5 × 10−3 and 1.1 × 10−3 cm2 V−1 S−1 for PTPACF and PTPA2CF, respectively. The polymer solar cells (PSCs were tested under the conventional device structure of ITO/PEDOT:PSS/polymer:PC71BM/PFN/Al. All of the PSCs showed the high open circuit voltages (Vocs with the values approaching 1 V. The PTPACF and PTPA2CF based PSCs gave the power conversion efficiencies (PCEs of 3.24% and 2.40%, respectively. Hence, it is a reliable methodology to develop high-performance large band-gap polymer donors with high Vocs through the feasible side-chain modification.

  8. Unraveling the High Open Circuit Voltage and High Performance of Integrated Perovskite/Organic Bulk-Heterojunction Solar Cells.

    Science.gov (United States)

    Dong, Shiqi; Liu, Yongsheng; Hong, Ziruo; Yao, Enping; Sun, Pengyu; Meng, Lei; Lin, Yuze; Huang, Jinsong; Li, Gang; Yang, Yang

    2017-08-09

    We have demonstrated high-performance integrated perovskite/bulk-heterojunction (BHJ) solar cells due to the low carrier recombination velocity, high open circuit voltage (V OC ), and increased light absorption ability in near-infrared (NIR) region of integrated devices. In particular, we find that the V OC of the integrated devices is dominated by (or pinned to) the perovskite cells, not the organic photovoltaic cells. A Quasi-Fermi Level Pinning Model was proposed to understand the working mechanism and the origin of the V OC of the integrated perovskite/BHJ solar cell, which following that of the perovskite solar cell and is much higher than that of the low bandgap polymer based organic BHJ solar cell. Evidence for the model was enhanced by examining the charge carrier behavior and photovoltaic behavior of the integrated devices under illumination of monochromatic light-emitting diodes at different characteristic wavelength. This finding shall pave an interesting possibility for integrated photovoltaic devices to harvest low energy photons in NIR region and further improve the current density without sacrificing V OC , thus providing new opportunities and significant implications for future industry applications of this kind of integrated solar cells.

  9. Recombination in polymer:Fullerene solar cells with open-circuit voltages approaching and exceeding 1.0 V

    KAUST Repository

    Hoke, Eric T.; Vandewal, Koen; Bartelt, Jonathan A.; Mateker, William R.; Douglas, Jessica D.; Noriega, Rodrigo; Graham, Kenneth; Frechet, Jean; Salleo, Alberto; McGehee, Michael D.

    2012-01-01

    Polymer:fullerene solar cells are demonstrated with power conversion efficiencies over 7% with blends of PBDTTPD and PC 61 BM. These devices achieve open-circuit voltages ( V oc ) of 0.945 V and internal quantum efficiencies of 88%, making them an ideal candidate for the large bandgap junction in tandem solar cells. V oc 's above 1.0 V are obtained when the polymer is blended with multiadduct fullerenes; however, the photocurrent and fill factor are greatly reduced. In PBDTTPD blends with multiadduct fullerene ICBA, fullerene emission is observed in the photoluminescence and electroluminescence spectra, indicating that excitons are recombining on ICBA. Voltage-dependent, steady state and time-resolved photoluminescence measurements indicate that energy transfer occurs from PBDTTPD to ICBA and that back hole transfer from ICBA to PBDTTPD is inefficient. By analyzing the absorption and emission spectra from fullerene and charge transfer excitons, we estimate a driving free energy of -0.14 ± 0.06 eV is required for efficient hole transfer. These results suggest that the driving force for hole transfer may be too small for efficient current generation in polymer:fullerene solar cells with V oc values above 1.0 V and that non-fullerene acceptor materials with large optical gaps ( > 1.7 eV) may be required to achieve both near unity internal quantum efficiencies and values of V oc exceeding 1.0 V. © 2013 WILEY-VCH Verlag GmbH and Co.

  10. Diphenylphenoxy-Thiophene-PDI Dimers as Acceptors for OPV Applications with Open Circuit Voltage Approaching 1 Volt

    Directory of Open Access Journals (Sweden)

    Caterina Stenta

    2018-03-01

    Full Text Available Two new perylenediimides (PDIs have been developed for use as electron acceptors in solution-processed bulk heterojunction solar cells. The compounds were designed to exhibit maximal solubility in organic solvents, and reduced aggregation in the solid state. In order to achieve this, diphenylphenoxy groups were used to functionalize a monomeric PDI core, and two PDI dimers were bridged with either one or two thiophene units. In photovoltaic devices prepared using PDI dimers and a monomer in conjunction with PTB7, it was found that the formation of crystalline domains in either the acceptor or donor was completely suppressed. Atomic force microscopy, X-ray diffraction, charge carrier mobility measurements and recombination kinetics studies all suggest that the lack of crystallinity in the active layer induces a significant drop in electron mobility. Significant surface recombination losses associated with a lack of segregation in the material were also identified as a significant loss mechanism. Finally, the monomeric PDI was found to have sub-optimum LUMO energy matching the cathode contact, thus limiting charge carrier extraction. Despite these setbacks, all PDIs produced high open circuit voltages, reaching almost 1 V in one particular case.

  11. Improved open-circuit voltage in Cu(In,Ga)Se{sub 2} solar cells with high work function transparent electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Jäger, Timo, E-mail: timo.jaeger@empa.ch; Romanyuk, Yaroslav E.; Bissig, Benjamin; Pianezzi, Fabian; Nishiwaki, Shiro; Reinhard, Patrick; Steinhauser, Jérôme; Tiwari, Ayodhya N. [Empa—Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Thin Films and Photovoltaics, Überlandstrasse 129, 8600 Dübendorf (Switzerland); Schwenk, Johannes [Empa—Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Nanoscale Materials Science, Überlandstrasse 129, 8600 Dübendorf (Switzerland)

    2015-06-14

    Hydrogenated indium oxide (IOH) is implemented as transparent front contact in Cu(In,Ga)Se{sub 2} (CIGS) solar cells, leading to an open circuit voltage V{sub OC} enhanced by ∼20 mV as compared to reference devices with ZnO:Al (AZO) electrodes. This effect is reproducible in a wide range of contact sheet resistances corresponding to various IOH thicknesses. We present the detailed electrical characterization of glass/Mo/CIGS/CdS/intrinsic ZnO (i-ZnO)/transparent conductive oxide (TCO) with different IOH/AZO ratios in the front TCO contact in order to identify possible reasons for the enhanced V{sub OC}. Temperature and illumination intensity-dependent current-voltage measurements indicate that the dominant recombination path does not change when AZO is replaced by IOH, and it is mainly limited to recombination in the space charge region and at the junction interface of the solar cell. The main finding is that the introduction of even a 5 nm-thin IOH layer at the i-ZnO/TCO interface already results in a step-like increase in V{sub OC}. Two possible explanations are proposed and verified by one-dimensional simulations using the SCAPS software. First, a higher work function of IOH as compared to AZO is simulated to yield an V{sub OC} increase by 21 mV. Second, a lower defect density in the i-ZnO layer as a result of the reduced sputter damage during milder sputter-deposition of IOH can also add to a maximum enhanced V{sub OC} of 25 mV. Our results demonstrate that the proper choice of the front TCO contact can reduce the parasitic recombination and boost the efficiency of CIGS cells with improved corrosion stability.

  12. A novel modeling methodology of open circuit voltage hysteresis for LiFePO4 batteries based on an adaptive discrete Preisach model

    International Nuclear Information System (INIS)

    Zhu, Letao; Sun, Zechang; Dai, Haifeng; Wei, Xuezhe

    2015-01-01

    Highlights: • An adaptive discrete Preisach model (ADPM) of OCV–SOC hysteresis is proposed. • The measured current is used to adjust the weight vector in the proposed ADPM. • A deformation algorithm of ADPM is developed for the accidental current errors. • The performance of ADPM under uncertainty of measured current is investigated. • The performance of ADPM under uncertainty of OCV is investigated. - Abstract: The relationship of open circuit voltage (OCV) versus state of charge (SOC) is critical for many techniques such as accurate battery modeling and reliable SOC estimation. However, the hysteresis existing in OCV–SOC curves of lithium-ion batteries complicates this relationship especially for lithium iron phosphate (LiFePO 4 ) batteries which exhibit a very flat OCV–SOC hysteretic feature. This paper aims at modeling the OCV–SOC hysteresis for LiFePO 4 batteries. The modeling approach is a novel adaptive discrete Preisach model (ADPM) based on the classic Preisach model and the least mean square (LMS) theory. To enhance the performance, the ADPM uses the measured current at each time step to adjust the weight vector. This method significantly decreases the errors (<1%) between the model predicted SOC and the true SOC acquired from experiments. A deformation algorithm of ADPM is further proposed to guarantee the performance even when large errors appear in the measured current. For further applications of the proposed ADPM such as SOC estimation, the robust performance of ADPM is also discussed when considering OCV input errors and measurement current errors. The results show that the maximum SOC calculation errors are about 6% and 5% respectively against uncertain OCV input and measured current which indicate the enormous potential of ADPM in battery management systems

  13. Suppression of the high-frequency disturbances in low-voltage circuits caused by disconnector operation in high-voltage open-air substations

    Energy Technology Data Exchange (ETDEWEB)

    Savic, M.S.

    1986-07-01

    The switching off and on of small capacitive currents charging busbar capacitances, connection conductors and open circuit breakers with disconnectors causes high-frequency transients in high-voltage networks. In low voltage circuits, these transient processes induce dangerous overvoltages for the electronic equipment in the substation. A modified construction of the disconnector with a damping resistor was investigated. Digital simulation of the transient process in a high-voltage network during the arcing period between the disconnector contacts with and without damping resistor were performed. A significant decrease of the arcing duration and the decrease of the electromagnetic field magnitude in the vicinity of the operating disconnector were noticed. In the low voltage circuit protected with the surge arrester, the overvoltage magnitude was not affected by the damping resistor due to the arrester protection effect.

  14. Open Circuit Resonant (SansEC) Sensor Technology for Lightning Mitigation and Damage Detection and Diagnosis for Composite Aircraft Applications

    Science.gov (United States)

    Szatkowski, George N.; Dudley, Kenneth L.; Smith, Laura J.; Wang, Chuantong; Ticatch, Larry A.

    2014-01-01

    Traditional methods to protect composite aircraft from lightning strike damage rely on a conductive layer embedded on or within the surface of the aircraft composite skin. This method is effective at preventing major direct effect damage and minimizes indirect effects to aircraft systems from lightning strike attachment, but provides no additional benefit for the added parasitic weight from the conductive layer. When a known lightning strike occurs, the points of attachment and detachment on the aircraft surface are visually inspected and checked for damage by maintenance personnel to ensure continued safe flight operations. A new multi-functional lightning strike protection (LSP) method has been developed to provide aircraft lightning strike protection, damage detection and diagnosis for composite aircraft surfaces. The method incorporates a SansEC sensor array on the aircraft exterior surfaces forming a "Smart skin" surface for aircraft lightning zones certified to withstand strikes up to 100 kiloamperes peak current. SansEC sensors are open-circuit devices comprised of conductive trace spiral patterns sans (without) electrical connections. The SansEC sensor is an electromagnetic resonator having specific resonant parameters (frequency, amplitude, bandwidth & phase) which when electromagnetically coupled with a composite substrate will indicate the electrical impedance of the composite through a change in its resonant response. Any measureable shift in the resonant characteristics can be an indication of damage to the composite caused by a lightning strike or from other means. The SansEC sensor method is intended to diagnose damage for both in-situ health monitoring or ground inspections. In this paper, the theoretical mathematical framework is established for the use of open circuit sensors to perform damage detection and diagnosis on carbon fiber composites. Both computational and experimental analyses were conducted to validate this new method and system for

  15. Effects of mass airflow rate through an open-circuit gas quantification system when measuring carbon emissions.

    Science.gov (United States)

    Gunter, Stacey A; Bradford, James A; Moffet, Corey A

    2017-01-01

    Methane (CH) and carbon dioxide (CO) represent 11 and 81%, respectively, of all anthropogenic greenhouse gas emissions. Agricultural CH emissions account for approximately 43% of all anthropogenic CH emissions. Most agricultural CH emissions are attributed to enteric fermentation within ruminant livestock; hence, the heightened interest in quantifying and mitigating this source. The automated, open-circuit gas quantification system (GQS; GreenFeed, C-Lock, Inc., Rapid City, SD) evaluated here can be placed in a pasture with grazing cattle and can measure their CH and CO emissions with spot sampling. However, improper management of the GQS can have an erroneous effect on emission estimates. One factor affecting the quality of emission estimates is the airflow rates through the GQS to ensure a complete capture of the breath cloud emitted by the animal. It is hypothesized that at lower airflow rates this cloud will be incompletely captured. To evaluate the effect of airflow rate through the GQS on emission estimates, a data set was evaluated with 758 CO and CH emission estimates with a range in airflows of 10.7 to 36.6 L/s. When airflow through the GQS was between 26.0 and 36.6 L/s, CO and CH emission estimates were not affected ( = 0.14 and 0.05, respectively). When airflow rates were less than 26.0 L/s, CO and CH emission estimates were lower and decreased as airflow rate decreased ( emissions are underestimated. Maintaining mass airflow through a GQS at rates greater than 26 L/s is important for producing high quality CO and CH emission estimates.

  16. Planar Perovskite Solar Cells with High Open-Circuit Voltage Containing a Supramolecular Iron Complex as Hole Transport Material Dopant.

    Science.gov (United States)

    Saygili, Yasemin; Turren-Cruz, Silver-Hamill; Olthof, Selina; Saes, Bartholomeus Wilhelmus Henricus; Pehlivan, Ilknur Bayrak; Saliba, Michael; Meerholz, Klaus; Edvinsson, Tomas; Zakeeruddin, Shaik M; Grätzel, Michael; Correa-Baena, Juan-Pablo; Hagfeldt, Anders; Freitag, Marina; Tress, Wolfgang

    2018-04-26

    In perovskite solar cells (PSCs), the most commonly used hole transport material (HTM) is spiro-OMeTAD, which is typically doped by metalorganic complexes, for example, based on Co, to improve charge transport properties and thereby enhance the photovoltaic performance of the device. In this study, we report a new hemicage-structured iron complex, 1,3,5-tris(5'-methyl-2,2'-bipyridin-5-yl)ethylbenzene Fe(III)-tris(bis(trifluoromethylsulfonyl)imide), as a p-type dopant for spiro-OMeTAD. The formal redox potential of this compound was measured as 1.29 V vs. the standard hydrogen electrode, which is slightly (20 mV) more positive than that of the commercial cobalt dopant FK209. Photoelectron spectroscopy measurements confirm that the iron complex acts as an efficient p-dopant, as evidenced in an increase of the spiro-OMeTAD work function. When fabricating planar PSCs with the HTM spiro-OMeTAD doped by 5 mol % of the iron complex, a power conversion efficiency of 19.5 % (AM 1.5G, 100 mW cm -2 ) is achieved, compared to 19.3 % for reference devices with FK209. Open circuit voltages exceeding 1.2 V at 1 sun and reaching 1.27 V at 3 suns indicate that recombination at the perovskite/HTM interface is low when employing this iron complex. This work contributes to recent endeavors to reduce recombination losses in perovskite solar cells. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. State of charge estimation of lithium-ion batteries using the open-circuit voltage at various ambient temperatures

    International Nuclear Information System (INIS)

    Xing, Yinjiao; He, Wei; Pecht, Michael; Tsui, Kwok Leung

    2014-01-01

    Highlights: • An offline OCV–SOC–temperature table was established to infer battery SOC. • A temperature-based model was developed to estimate SOC at different temperatures. • The algorithm for SOC estimation was verified by dynamic current load. • The robustness of the approach was validated by different initial SOC values. - Abstract: Ambient temperature is a significant factor that influences the accuracy of battery SOC estimation, which is critical for remaining driving range prediction of electric vehicles (EVs) and optimal charge/discharge control of batteries. A widely used method to estimate SOC is based on an online inference of open-circuit voltage (OCV). However, the fact that the OCV–SOC is dependent on ambient temperature can result in errors in battery SOC estimation. To address this problem, this paper presents an SOC estimation approach based on a temperature-based model incorporated with an OCV–SOC–temperature table. The unscented Kalman filtering (UKF) was applied to tune the model parameters at each sampling step to cope with various uncertainties arising from the operation environment, cell-to-cell variation, and modeling inaccuracy. Two dynamic tests, the dynamic stress test (DST) and the federal urban driving schedule (FUDS), were used to test batteries at different temperatures. Then, DST was used to identify the model parameters while FUDS was used to validate the performance of the SOC estimation. The estimation was made covering the major working range from 25% to 85% SOC. The results indicated that our method can provide accurate SOC estimation with smaller root mean squared errors than the method that does not take into account ambient temperature. Thus, our approach is effective and accurate when battery operates at different ambient temperatures. Since the developed method takes into account the temperature factor as well as the complexity of the model, it could be effectively applied in battery management systems for

  18. The Fault Detection, Localization, and Tolerant Operation of Modular Multilevel Converters with an Insulated Gate Bipolar Transistor (IGBT Open Circuit Fault

    Directory of Open Access Journals (Sweden)

    Wei Li

    2018-04-01

    Full Text Available Reliability is one of the critical issues for a modular multilevel converter (MMC since it consists of a large number of series-connected power electronics submodules (SMs. In this paper, a complete control strategy including fault detection, localization, and tolerant operation is proposed for the MMC under an insulated gate bipolar transistor (IGBT open circuit fault. According to the output characteristics of the SM with the open-circuit fault of IGBT, a fault detection method based on the circulating current and output current observation is used. In order to further precisely locate the position of the faulty SM, a fault localization method based on the SM capacitor voltage observation is developed. After the faulty SM is isolated, the continuous operation of the converter is ensured by adopting the fault-tolerant strategy based on the use of redundant modules. To verify the proposed fault detection, fault localization, and fault-tolerant operation strategies, a 900 kVA MMC system under the conditions of an IGBT open circuit is developed in the Matlab/Simulink platform. The capabilities of rapid detection, precise positioning, and fault-tolerant operation of the investigated detection and control algorithms are also demonstrated.

  19. Polypyrrole: FeOx·ZnO nanoparticle solar cells with breakthrough open-circuit voltage prepared from relatively stable liquid dispersions

    KAUST Repository

    Zong, Baoyu

    2014-01-01

    Organic hybrid solar cells with a large open-circuit voltage, up to above that of 1.5 V standard battery voltage, were demonstrated using blends of polypyrrole: Fe2O3·ZnO nanoparticles as active-layers. The cell active-layers were readily coated in open air from relatively stable liquid dark-color polypyrrole-based dispersions, which were synthesized using appropriate surfactants during the in situ polymerization of pyrrole with FeCl3 or both H2O2 and FeCl3 as the oxidizers. The performance of the cells depends largely on the synthesized blend phase, which is determined by the surfactants, oxidizers, as well as the reactant ratio. Only the solar cells fabricated from the stable dispersions can produce both a high open-circuit voltage (>1.0 V) and short-circuit current (up to 7.5 mA cm-2) due to the relatively uniform porous network nanomorphology and higher shunt to series resistance ratio of the active-layers. The cells also display a relatively high power-conversion efficiency of up to ∼3.8%. This journal is

  20. Maximum forseeable accident analysis made by a sodium leak on the BN-800 primary circuit and the more constraining accident development scenario

    International Nuclear Information System (INIS)

    Ivanenko, V.N.; Zybin, V.A.

    1988-01-01

    In this paper the different ways of development for the BN-800 maximum credible accident in case of loss and fire of primary sodium are examined. The more constraining scenario is presented. During the scenario analysis the accidental release of radioactive materials in the environment has been studied. These releases are below the authorized values [fr

  1. Design and flight performance evaluation of the Mariners 6, 7, and 9 short-circuit current, open-circuit voltage transducers

    Science.gov (United States)

    Patterson, R. E.

    1973-01-01

    The purpose of the short-circuit voltage transducer is to provide engineering data to aid the evaluation of array performance during flight. The design, fabrication, calibration, and in-flight performance of the transducers onboard the Mariner 6, 7 and 9 spacecrafts are described. No significant differences were observed in the in-flight electrical performance of the three transducers. The transducers did experience significant losses due to coverslides or adhesive darkening, increased surface reflection, or spectral shifts within coverslide assembly. Mariner 6, 7 and 9 transducers showed non-cell current degradations of 3-1/2%, 3%, and 4%, respectively at Mars encounter and 6%, 3%, and 4-12%, respectively at end of mission. Mariner 9 solar Array Test 2 showed 3-12% current degradation while the transducer showed 4-12% degradation.

  2. Beat the Deviations in Estimating Maximum Power of Thermoelectric Modules

    DEFF Research Database (Denmark)

    Gao, Junling; Chen, Min

    2013-01-01

    Under a certain temperature difference, the maximum power of a thermoelectric module can be estimated by the open-circuit voltage and the short-circuit current. In practical measurement, there exist two switch modes, either from open to short or from short to open, but the two modes can give...... different estimations on the maximum power. Using TEG-127-2.8-3.5-250 and TEG-127-1.4-1.6-250 as two examples, the difference is about 10%, leading to some deviations with the temperature change. This paper analyzes such differences by means of a nonlinear numerical model of thermoelectricity, and finds out...... that the main cause is the influence of various currents on the produced electromotive potential. A simple and effective calibration method is proposed to minimize the deviations in specifying the maximum power. Experimental results validate the method with improved estimation accuracy....

  3. Building mechanism for a high open-circuit voltage in an all-solution-processed tandem polymer solar cell.

    Science.gov (United States)

    Kong, Jaemin; Lee, Jongjin; Kim, Geunjin; Kang, Hongkyu; Choi, Youna; Lee, Kwanghee

    2012-08-14

    Additional post-processing techniques, such as post-thermal annealing and UV illumination, were found to be required to obtain desirable values of the cell parameters in a tandem polymer solar cell incorporated with solution-processed basic n-type titanium sub-oxide (TiO(x))/acidic p-type poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) interlayers. Subsequent to the fabrication of the tandem polymer solar cells, the open-circuit voltage (V(OC)) of the cells exhibited half of the expected value. Only after the application of the post-treatments, the V(OC) of a tandem cell increased from the initial half-cell value (∼0.6 V) to its full-cell value (∼1.2 V). The selective light-biased incident photon-to-current efficiency (IPCE) measurements indicated that the initial V(OC) originated from the back subcell and that the application of the post-processing treatments revived the front subcell, such that the net photocurrent of the tandem cell was finally governed by a recombination process of holes from the back subcell and electrons from the front subcell. Based on our experimental results, we suggest that a V(OC) enhancement could be ascribed to two types of subsequent junction formations at the interface between the TiO(x) and PEDOT:PSS interlayers: an 'ion-mediated dipole junction', resulting from the electro-kinetic migration of cationic ions in the interlayers during post-thermal annealing in the presence of a low-work-function metal cathode, and a 'photoinduced Schottky junction', formed by increasing the charge carrier density in the n-type TiO(x) interlayer during UV illumination process. The two junctions separately contributed to the formation of a recombination junction through which the electrons in TiO(x) and the holes in PEDOT:PSS were able to recombine without substantial voltage drops.

  4. Enhancing the open-circuit voltage of dye-sensitized solar cells: coadsorbents and alternative redox couples[Dissertation 4066

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.

    2008-04-15

    In February 2008, the oil price easily exceeded US dollar 100 per barrel due to the weak US dollar and the imbalance between the increasing demands and deficient supplies. People are paying more and more attention to seek for alternative energy sources that would suffice the modern society in the following high-oil-price era. The work in this thesis is associated with some fundamental research in one of the solutions to the energy shortage, photovoltaics. Particularly, the dye-sensitized solar cell was taken as the system where the effects of coadsorbents and alternative couples to the classic iodide/iodine redox were studied and rationalized. The first chapter was a general introduction to the photovoltaics and dye-sensitized solar cells, such as the operating principles and the characteristics of the dye cell. In Chapter 2, we specified all the experimental issues, including the chemicals, materials, film preparation, characterization techniques and data analysis. A short part was also dedicated to the basics of the photovoltaics. We studied the electronic effect of the scattering particles in our devices in Chapter 3. These particles were of 400 nm in diameter and always put on top of the nanotransparent layer to increase the light harvesting of the devices. It was found that the particles gave a small dark current but under illumination, they made a significant contribution to the total photocurrent. Photovoltage and photocurrent transient decay measurements performed under bias illumination showed that the density of electronic states of the light scattering layer was two times smaller than that of a transparent nanoparticle layer. From Chapter 4 to Chapter 7, we systematically studied the function of the coadsorbents. Application of an {omega}-guannidino carboxylic acid was found to increase the open-circuit voltage of the device by 50 mV. Coadsorbents with similar structures were then employed with an amphiphilic ruthenium sensitizer, Z-907, to scrutinize

  5. Color Coding of Circuit Quantities in Introductory Circuit Analysis Instruction

    Science.gov (United States)

    Reisslein, Jana; Johnson, Amy M.; Reisslein, Martin

    2015-01-01

    Learning the analysis of electrical circuits represented by circuit diagrams is often challenging for novice students. An open research question in electrical circuit analysis instruction is whether color coding of the mathematical symbols (variables) that denote electrical quantities can improve circuit analysis learning. The present study…

  6. An open circuit voltage equation enabling separation of cathode and anode polarization resistances of ceria electrolyte based solid oxide fuel cells

    Science.gov (United States)

    Zhang, Yanxiang; Chen, Yu; Yan, Mufu

    2017-07-01

    The open circuit voltage (OCV) of solid oxide fuel cells is generally overestimated by the Nernst equation and the Wagner equation, due to the polarization losses at electrodes. Considering both the electronic conduction of electrolyte and the electrode polarization losses, we express the OCV as an implicit function of the characteristic oxygen pressure of electrolyte (p* [atm], at which the electronic and ionic conductivities are the same), and the relative polarization resistance of electrodes (rc = Rc/Ri and ra = Ra/Ri, where Ri/c/a [Ωcm2] denotes the ionic resistance of electrolyte, and the polarization resistances of cathode and anode, respectively). This equation approaches to the Wagner equation when the electrodes are highly active (rc and ra → 0), and approaches to the Nernst equation when the electrolyte is a purely ionic conductor (p* → 0). For the fuel cells whose OCV is well below the prediction of the Wagner equation, for example with thin doped ceria electrolyte, it is demonstrated that the combination of OCV and impedance spectroscopy measurements allows the determination of p*, Rc and Ra. This equation can serve as a simple yet powerful tool to study the internal losses in the cell under open circuit condition.

  7. In situ monitoring the effects of a magnetic field on the open-circuit corrosion states of iron in acidic and neutral solutions

    International Nuclear Information System (INIS)

    Lu Zhanpeng; Yang Wu

    2008-01-01

    The effects of a 0.4 T horizontal magnetic field (HMF) on the open-circuit corrosion states of iron in static aqueous solutions are studied by in situ monitoring the responses of two electrochemical parameters to the applied magnetic field, i.e. the open-circuit potential (OCP) and the current under potentiostatic polarization. The applied magnetic field makes the OCP shift in the noble direction. Withdrawing the magnetic field causes a negative shift of the OCP in acidic solutions, but it does not cause any significant change of OCP in neutral solutions. Imposing a magnetic field induces a cathodic current for iron that was previously potentiostatically polarized at the OCP without magnetic field. Withdrawing the magnetic field induces an anodic current for iron that was previously potentiostatically polarized at the OCP with the magnetic field. The magnetic field effect is more significant in the acid solutions than in the salt solutions. The magnetic field effects on the oxygen reduction and on the activation-controlled iron dissolution reaction are found to be insignificant. The magnetic field effect on the hydrogen reduction reaction on iron in acidic solutions is demonstrated. Results show the possibility that a magnetic field would affect the hydrogen evolution by enhancing the electron-transfer process that has been categorized in the classical electrochemistry kinetics to be the rate-determining process. The memory effect of the magnetic field on the electrochemical reaction is identified and discussed

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

    International Nuclear Information System (INIS)

    Salehi Arashloo, Ramin; Salehifar, Mehdi; Romeral, Luis; Sala, Vicent

    2015-01-01

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

  9. Estimation of maximum pressure in small containments of PWR reactors due to loss of coolant accident in primary circuit; Estimativa da pressao maxima em contencoes de reatores PWR de pequeno porte devido a um acidente de perda de refrigerante no circuito primario

    Energy Technology Data Exchange (ETDEWEB)

    Mendes Neto, Teofilo [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Moreira, Joao Manoel Losada [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), SP (Brazil)

    2000-07-01

    This work studies the problem of containment pressurization after a LOCA in reactors with small containment free volumes. The relationship between the reactor power and the containment free volume is described with the ratio between the volumes of the primary circuit and of the containment. The maximum pressure in a containment, following a LOCA, obtained after a correlation based on large containment PWR, is around 185 psia for a primary circuit and containment volumes ratio of 0.025. For the same problem, calculations with the CONTEMPT-LT code produced a maximum pressure of 162 psia. The behavior of the temperature after a LOCA to the containment, as a function of the ratio between the primary circuit and containment volume, is such that it increases reaching asymptotically to a maximum; differently, the pressure increases almost linearly with the ratio of volumes. (author)

  10. Extra high speed modified Lundell alternator parameters and open/short-circuit characteristics from global 3D-FE magnetic field solutions

    Science.gov (United States)

    Wang, R.; Demerdash, N. A.

    1992-06-01

    The combined magnetic vector potential - magnetic scalar potential method of computation of 3D magnetic fields by finite elements, introduced in a companion paper, is used for global 3D field analysis and machine performance computations under open-circuit and short-circuit conditions for an example 14.3 kVA modified Lundell alternator, whose magnetic field is of intrinsic 3D nature. The computed voltages and currents under these machine test conditions were verified and found to be in very good agreement with corresponding test data. Results of use of this modelling and computation method in the study of a design alteration example, in which the stator stack length of the example alternator is stretched in order to increase voltage and volt-ampere rating, are given here. These results demonstrate the inadequacy of conventional 2D-based design concepts and the imperative of use of this type of 3D magnetic field modelling in the design and investigation of such machines.

  11. Extra high speed modified Lundell alternator parameters and open/short-circuit characteristics from global 3D-FE magnetic field solutions

    Science.gov (United States)

    Wang, R.; Demerdash, N. A.

    1992-01-01

    The combined magnetic vector potential - magnetic scalar potential method of computation of 3D magnetic fields by finite elements, introduced in a companion paper, is used for global 3D field analysis and machine performance computations under open-circuit and short-circuit conditions for an example 14.3 kVA modified Lundell alternator, whose magnetic field is of intrinsic 3D nature. The computed voltages and currents under these machine test conditions were verified and found to be in very good agreement with corresponding test data. Results of use of this modelling and computation method in the study of a design alteration example, in which the stator stack length of the example alternator is stretched in order to increase voltage and volt-ampere rating, are given here. These results demonstrate the inadequacy of conventional 2D-based design concepts and the imperative of use of this type of 3D magnetic field modelling in the design and investigation of such machines.

  12. Online Estimation of Model Parameters and State of Charge of LiFePO4 Batteries Using a Novel Open-Circuit Voltage at Various Ambient Temperatures

    Directory of Open Access Journals (Sweden)

    Fei Feng

    2015-04-01

    Full Text Available This study describes an online estimation of the model parameters and state of charge (SOC of lithium iron phosphate batteries in electric vehicles. A widely used SOC estimator is based on the dynamic battery model with predeterminate parameters. However, model parameter variances that follow with their varied operation temperatures can result in errors in estimating battery SOC. To address this problem, a battery online parameter estimator is presented based on an equivalent circuit model using an adaptive joint extended Kalman filter algorithm. Simulations based on actual data are established to verify accuracy and stability in the regression of model parameters. Experiments are also performed to prove that the proposed estimator exhibits good reliability and adaptability under different loading profiles with various temperatures. In addition, open-circuit voltage (OCV is used to estimate SOC in the proposed algorithm. However, the OCV based on the proposed online identification includes a part of concentration polarization and hysteresis, which is defined as parametric identification-based OCV (OCVPI. Considering the temperature factor, a novel OCV–SOC relationship map is established by using OCVPI under various temperatures. Finally, a validating experiment is conducted based on the consecutive loading profiles. Results indicate that our method is effective and adaptable when a battery operates at different ambient temperatures.

  13. Subnanometer Ga 2 O 3 Tunnelling Layer by Atomic Layer Deposition to Achieve 1.1 V Open-Circuit Potential in Dye-Sensitized Solar Cells

    KAUST Repository

    Chandiran, Aravind Kumar

    2012-08-08

    Herein, we present the first use of a gallium oxide tunnelling layer to significantly reduce electron recombination in dye-sensitized solar cells (DSC). The subnanometer coating is achieved using atomic layer deposition (ALD) and leading to a new DSC record open-circuit potential of 1.1 V with state-of-the-art organic D-π-A sensitizer and cobalt redox mediator. After ALD of only a few angstroms of Ga 2O 3, the electron back reaction is reduced by more than an order of magnitude, while charge collection efficiency and fill factor are increased by 30% and 15%, respectively. The photogenerated exciton separation processes of electron injection into the TiO 2 conduction band and the hole injection into the electrolyte are characterized in detail. © 2012 American Chemical Society.

  14. Subnanometer Ga2O3 tunnelling layer by atomic layer deposition to achieve 1.1 V open-circuit potential in dye-sensitized solar cells.

    Science.gov (United States)

    Chandiran, Aravind Kumar; Tetreault, Nicolas; Humphry-Baker, Robin; Kessler, Florian; Baranoff, Etienne; Yi, Chenyi; Nazeeruddin, Mohammad Khaja; Grätzel, Michael

    2012-08-08

    Herein, we present the first use of a gallium oxide tunnelling layer to significantly reduce electron recombination in dye-sensitized solar cells (DSC). The subnanometer coating is achieved using atomic layer deposition (ALD) and leading to a new DSC record open-circuit potential of 1.1 V with state-of-the-art organic D-π-A sensitizer and cobalt redox mediator. After ALD of only a few angstroms of Ga(2)O(3), the electron back reaction is reduced by more than an order of magnitude, while charge collection efficiency and fill factor are increased by 30% and 15%, respectively. The photogenerated exciton separation processes of electron injection into the TiO(2) conduction band and the hole injection into the electrolyte are characterized in detail.

  15. Relationship between open-circuit voltage in Cu(In,Ga)Se2 solar cell and peak position of (220/204) preferred orientation near its absorber surface

    International Nuclear Information System (INIS)

    Chantana, J.; Minemoto, T.; Watanabe, T.; Teraji, S.; Kawamura, K.

    2013-01-01

    Cu(In,Ga)Se 2 (CIGS) absorbers with various Ga/III, Ga/(In+Ga), profiles are prepared by the so-called “multi-layer precursor method” using multi-layer co-evaporation of material sources. It is revealed that open-circuit voltage (V OC ) of CIGS solar cell is primarily dependent on averaged Ga/III near the surface of its absorber. This averaged Ga/III is well predicted by peak position of (220/204) preferred orientation of CIGS film near its surface investigated by glancing-incidence X-ray diffraction with 0.1° incident angle. Finally, the peak position of (220/204) preferred orientation is proposed as a measure of V OC before solar cell fabrication

  16. On the Predictions of Carbon Deposition on the Nickel Anode of a SOFC and Its Impact on Open-Circuit Conditions

    KAUST Repository

    Lee, W. Y.

    2012-12-04

    Previous thermodynamic analyses of carbon formation in SOFCs assumed that graphite could be used to represent the properties of carbon formed in the anode. It is generally observed, however, that catalytically grown carbon nanofibers (CNF) are more likely to form in the SOFC anode with nickel catalysts. The energetic and entropic properties of CNF are different from those of graphite.We compare equilibrium results based on thermochemical properties for graphite, to new results based on a previously reported value of an empirically determined Gibbs free energy for carbon fibers grown on a nickel support (with fitted values of H°CNF = 54.46 kJ/mol and S°CNF = 68.90 J/mol/K for a nickel crystal size of 5.4 nm). There is little difference in predictions of carbon formation under open-circuit conditions between the two carbon types for methane mixtures, with graphite predicted to form at lower temperatures than CNF. There is a much bigger difference in predictions for methanol mixtures, especially at low steam-carbon ratios. The differences for propane are even more pronounced, and the improved predictions assuming CNF are in closer agreement with past observations.We show a strong dependence of CNF formation and "coking threshold" on nickel crystallite size, supporting previous reports that the nickel particle size is a dominating parameter for controlling filament growth. If both carbon types are included in the calculations, only the thermodynamically favored form (i.e., the type having the lowest formation energy) exists. Predicted Nernst potentials are more-or-less independent of the carbon type and in agreement with measured open-circuit voltages. © 2012 The Electrochemical Society.

  17. Improve the open-circuit voltage of ZnO solar cells with inserting ZnS layers by two ways

    International Nuclear Information System (INIS)

    Sun, Yunfei; Yang, Jinghai; Yang, Lili; Cao, Jian; Gao, Ming; Zhang, Zhiqiang; Wang, Zhe; Song, Hang

    2013-01-01

    ZnS NPs layers were deposited on ZnO NRs by two different ways. One is spin coating; the other is successive ionic layer adsorption and reaction (SILAR) method. The ZnO NRs/ZnS NPs composites were verified by X-ray diffraction, X-ray photoelectron spectroscopy, and UV–visible spectrophotometer; their morphologies and thicknesses were examined by scanning electron microscopic and transmission electron microscopic images. The CdS quantum dot sensitized solar cells (QDSSCs) were constructed using ZnO NRs/ZnS NPs composites as photoanode and their photovoltaic characteristic was studied by J–V curves. The results indicated that the way of SILAR is more beneficial for retarding the back transfer of electrons to CdS and electrolyte than spin coating method. The open-circuit voltage increased to 0.59 V by introducing a ZnS layer through SILAR method. When ZnS NPs layer was deposited for 10 times on ZnO NRs, the conversion efficiency of QDSSC shows ∼3.3 folds increments of as-synthesized ZnO solar cell. - Graphical abstract: When ZnO nanorods were deposited by ZnS for 10 times, the conversion efficiency of QDSSC shows ∼3.3 folds increments of as-synthesized ZnO solar cell. Highlights: ► ZnS layers were deposited with two different ways. ► The way of SILAR is more beneficial for retarding the back transfer of electrons. ► The open-circuit voltage increased to 0.59 V by introducing a ZnS layer through SILAR method

  18. Improve the open-circuit voltage of ZnO solar cells with inserting ZnS layers by two ways

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yunfei [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Yang, Jinghai, E-mail: jhyang1@jlnu.edu.cn [Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Yang, Lili; Cao, Jian [Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Gao, Ming [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Zhang, Zhiqiang; Wang, Zhe [Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Song, Hang [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

    2013-04-15

    ZnS NPs layers were deposited on ZnO NRs by two different ways. One is spin coating; the other is successive ionic layer adsorption and reaction (SILAR) method. The ZnO NRs/ZnS NPs composites were verified by X-ray diffraction, X-ray photoelectron spectroscopy, and UV–visible spectrophotometer; their morphologies and thicknesses were examined by scanning electron microscopic and transmission electron microscopic images. The CdS quantum dot sensitized solar cells (QDSSCs) were constructed using ZnO NRs/ZnS NPs composites as photoanode and their photovoltaic characteristic was studied by J–V curves. The results indicated that the way of SILAR is more beneficial for retarding the back transfer of electrons to CdS and electrolyte than spin coating method. The open-circuit voltage increased to 0.59 V by introducing a ZnS layer through SILAR method. When ZnS NPs layer was deposited for 10 times on ZnO NRs, the conversion efficiency of QDSSC shows ∼3.3 folds increments of as-synthesized ZnO solar cell. - Graphical abstract: When ZnO nanorods were deposited by ZnS for 10 times, the conversion efficiency of QDSSC shows ∼3.3 folds increments of as-synthesized ZnO solar cell. Highlights: ► ZnS layers were deposited with two different ways. ► The way of SILAR is more beneficial for retarding the back transfer of electrons. ► The open-circuit voltage increased to 0.59 V by introducing a ZnS layer through SILAR method.

  19. Effects of the charge-transfer reorganization energy on the open-circuit voltage in small-molecular bilayer organic photovoltaic devices: comparison of the influence of deposition rates of the donor.

    Science.gov (United States)

    Lee, Chih-Chien; Su, Wei-Cheng; Chang, Wen-Chang

    2016-05-14

    The theoretical maximum of open-circuit voltage (VOC) of organic photovoltaic (OPV) devices has yet to be determined, and its origin remains debated. Here, we demonstrate that VOC of small-molecule OPV devices can be improved by controlling the deposition rate of a donor without changing the interfacial energy gap at the donor/acceptor interface. The measurement of external quantum efficiency and electroluminescence spectra facilitates the observation of the existence of charge transfer (CT) states. A simplified approach by reusing the reciprocity relationship for obtaining the properties of the CT states is proposed without introducing complex techniques. We compare experimental and fitting results and propose that reorganization energy is the primary factor in determining VOC instead of either the CT energy or electronic coupling term in bilayer OPV devices. Atomic force microscopy images indicate a weak molecular aggregation when a higher deposition rate is used. The results of temperature-dependent measurements suggest the importance of molecular stacking for the CT properties.

  20. Fine Tuning of Open-Circuit Voltage by Chlorination in Thieno[3,4- b ]thiophene–Benzodithiophene Terpolymers toward Enhanced Solar Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Shiwei; Wang, Huan; Mo, Daize; Chao, Pengjie; Yang, Zhen; Li, Longji; Tian, Leilei; Chen, Wei [Materials; Institute; He, Feng

    2017-06-22

    A new family of thieno[3,4-b]thiophene benzodithiophene terpolymers (PBTClx) have been designed and synthesized, in which the chlorine/fluorine content has been adjusted and optimized. As the content of chlorine is increased in polymers, the twist angle between the donor and acceptor is increased, which leads to a diminishment in the planarity and conjugation. As a result, the UV vis absorption is continuous blue-shifted, and the band gap increases from 1.57 to 2.04 eV when the chlorinated moieties increased from 0 to 100%. The highest occupied molecular orbital (HOMO) levels of those polymers are decreased by increasing the content of chlorinated moiety, which opens a window to constantly modify the V-oc values and eventually meets a balance point for optimized solar energy conversion. The highest power conversion efficiency of 8.31% is obtained by using PBTCl25 as the donor and PC71BM as the acceptor in polymer solar cells (PSCs), in which the Voc increased from 0.79 to 0.82 V after 25% chlorinated monomer involved in copolymerization. Herein, the chlorine replacement could be a good method to further pump the solar conversion by increasing the open circuit voltage without reducing other factors of the polymer solar cells.

  1. Oscillator circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

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

  2. Measuring circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

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

  3. Current-mode minimax circuit

    NARCIS (Netherlands)

    Wassenaar, R.F.

    1992-01-01

    The minimum-maximum (minimax) circuit selects the minimum and maximum of two input currents. Four transistors in matched pairs are operated in the saturation region. Because the behavior of the circuit is based on matched devices and is independent of the relationship between the drain current and

  4. Thieno[3,4-c]Pyrrole-4,6-Dione-Based Polymer Acceptors for High Open-Circuit Voltage All-Polymer Solar Cells

    KAUST Repository

    Liu, Shengjian

    2017-04-20

    While polymer acceptors are promising fullerene alternatives in the fabrication of efficient bulk heterojunction (BHJ) solar cells, the range of efficient material systems relevant to the “all-polymer” BHJ concept remains narrow, and currently limits the perspectives to meet the 10% efficiency threshold in all-polymer solar cells. This report examines two polymer acceptor analogs composed of thieno[3,4-c]pyrrole-4,6-dione (TPD) and 3,4-difluorothiophene ([2F]T) motifs, and their BHJ solar cell performance pattern with a low-bandgap polymer donor commonly used with fullerenes (PBDT-TS1; taken as a model system). In this material set, the introduction of a third electron-deficient motif, namely 2,1,3-benzothiadiazole (BT), is shown to (i) significantly narrow the optical gap (Eopt) of the corresponding polymer (by ≈0.2 eV) and (ii) improve the electron mobility of the polymer by over two orders of magnitude in BHJ solar cells. In turn, the narrow-gap P2TPDBT[2F]T analog (Eopt = 1.7 eV) used as fullerene alternative yields high open-circuit voltages (VOC) of ≈1.0 V, notable short-circuit current values (JSC) of ≈11.0 mA cm−2, and power conversion efficiencies (PCEs) nearing 5% in all-polymer BHJ solar cells. P2TPDBT[2F]T paves the way to a new, promising class of polymer acceptor candidates.

  5. Enhancement of open-circuit voltage on organic photovoltaic devices by Al-doped TiO{sub 2} modifying layer produced by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Valaski, R.; Arantes, C.; Senna, C.A.; Carôzo, Victor; Achete, C.A. [Materials Metrology Division, Instituto Nacional de Metrologia, Qualidade e Tecnologia, Xerém, Duque de Caxias 25250-020, RJ (Brazil); Cremona, M., E-mail: cremona@fis.puc-rio.br [Materials Metrology Division, Instituto Nacional de Metrologia, Qualidade e Tecnologia, Xerém, Duque de Caxias 25250-020, RJ (Brazil); Physics Department, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro 22453-970, RJ (Brazil)

    2014-12-01

    Sol–gel method has shown several advantages for oxide synthesis, such as lower cost production, coating large areas, lower processing temperatures and ease insertion of doping materials. Therefore, it is attractive for production of intermediate and electrode modifying layers in organic optoelectronic devices. Herein, spin-coated aluminum-doped titanium dioxide (AlTiO{sub 2}) thin films were produced by sol–gel method onto glass and fluorine-doped tin oxide (FTO) substrates, using different Al-dopant concentrations and post-done annealing temperatures. Electrical measurements were performed in order to investigate the improvement of the TiO{sub 2} resistivity. Additionally, structural, compositional, morphological, optical and electrical properties of the optimal AlTiO{sub 2} modifying layers onto FTO substrates were probed by different techniques, and compared with those obtained from the undoped thin films produced under similar conditions. Organic photovoltaic devices (OPVs) with the structure FTO/AlTiO{sub 2}(30 nm)/C{sub 60}(50 nm)/CuPc(50 nm)/Al with an Al concentration of 0.03 M in AlTiO{sub 2} layer were produced. The insertion of AlTiO{sub 2} thin films improved the short-circuit current density (J{sub sc}) as well as the open circuit voltage (V{sub oc}) in comparison with non-modified electrode FTO based devices. This behavior is discussed in terms of induced interface phenomena as dipole formation induced by Al. - Highlights: • Easy and cheap solution-process for AlTiO{sub 2} modification of FTO electrode for OPVs • Electrical, structural and optical characterization of TiO{sub 2} layers with Al-dopant • Improvement of Voc and Jsc of inverted OPVs with AlTiO{sub 2} modified electrode.

  6. Enhancement of open-circuit voltage on organic photovoltaic devices by Al-doped TiO2 modifying layer produced by sol–gel method

    International Nuclear Information System (INIS)

    Valaski, R.; Arantes, C.; Senna, C.A.; Carôzo, Victor; Achete, C.A.; Cremona, M.

    2014-01-01

    Sol–gel method has shown several advantages for oxide synthesis, such as lower cost production, coating large areas, lower processing temperatures and ease insertion of doping materials. Therefore, it is attractive for production of intermediate and electrode modifying layers in organic optoelectronic devices. Herein, spin-coated aluminum-doped titanium dioxide (AlTiO 2 ) thin films were produced by sol–gel method onto glass and fluorine-doped tin oxide (FTO) substrates, using different Al-dopant concentrations and post-done annealing temperatures. Electrical measurements were performed in order to investigate the improvement of the TiO 2 resistivity. Additionally, structural, compositional, morphological, optical and electrical properties of the optimal AlTiO 2 modifying layers onto FTO substrates were probed by different techniques, and compared with those obtained from the undoped thin films produced under similar conditions. Organic photovoltaic devices (OPVs) with the structure FTO/AlTiO 2 (30 nm)/C 60 (50 nm)/CuPc(50 nm)/Al with an Al concentration of 0.03 M in AlTiO 2 layer were produced. The insertion of AlTiO 2 thin films improved the short-circuit current density (J sc ) as well as the open circuit voltage (V oc ) in comparison with non-modified electrode FTO based devices. This behavior is discussed in terms of induced interface phenomena as dipole formation induced by Al. - Highlights: • Easy and cheap solution-process for AlTiO 2 modification of FTO electrode for OPVs • Electrical, structural and optical characterization of TiO 2 layers with Al-dopant • Improvement of Voc and Jsc of inverted OPVs with AlTiO 2 modified electrode

  7. Comparison of Reef Fish Survey Data Gathered by Open and Closed Circuit SCUBA Divers Reveals Differences in Areas With Higher Fishing Pressure.

    Directory of Open Access Journals (Sweden)

    Andrew E Gray

    Full Text Available Visual survey by divers using open-circuit (OC SCUBA is the most widely used approach to survey coral reef fishes. Therefore, it is important to quantify sources of bias in OC surveys, such as the possibility that avoidance of OC divers by fishes can lead to undercounting in areas where targeted species have come to associate divers with a risk of being speared. One potential way to reduce diver avoidance is to utilize closed circuit rebreathers (CCRs, which do not produce the noise and bubbles that are a major source of disturbance associated with OC diving. For this study, we conducted 66 paired OC and CCR fish surveys in the Main Hawaiian Islands at locations with relatively high, moderate, and light fishing pressure. We found no significant differences in biomass estimates between OC and CCR surveys when data were pooled across all sites, however there were differences at the most heavily fished location, Oahu. There, biomass estimates from OC divers were significantly lower for several targeted fish groups, including surgeonfishes, targeted wrasses, and snappers, as well as for all targeted fishes combined, with mean OC biomass between 32 and 68% of mean CCR biomass. There were no clear differences between OC and CCR biomass estimates for these groups at sites with moderate or low fishing pressure, or at any location for other targeted fish groups, including groupers, parrotfishes, and goatfishes. Bias associated with avoidance of OC divers at heavily fished locations could be substantially reduced, or at least calibrated for, by utilization of CCR. In addition to being affected by fishing pressure, the extent to which avoidance of OC divers is problematic for visual surveys varies greatly among taxa, and is likely to be highly influenced by the survey methodology and dimensions used.

  8. Electron-deficient N-alkyloyl derivatives of thieno[3,4-c]pyrrole-4,6-dione yield efficient polymer solar cells with open-circuit voltages > 1 v

    KAUST Repository

    Warnan, Julien; Cabanetos, Clement; Bude, Romain; El Labban, Abdulrahman; LI, LIANG; Beaujuge, Pierre

    2014-01-01

    Poly(benzo[1,2-b:4,5-b′]dithiophene-thieno[3,4-c]pyrrole-4,6-dione) (PBDTTPD) polymer donors yield some of the highest open-circuit voltages (V OC, ca. 0.9 V) and fill factors (FF, ca. 70%) in conventional bulk-heterojunction (BHJ) solar cells

  9. Diode laser trans - scleral cyclo - ablation as a primary surgical treatment for primary open - angle glaucoma after maximum tolerated medical therapy

    International Nuclear Information System (INIS)

    Mahmood, K.; Khan, M.T.; Butt, J.B.Y.

    2011-01-01

    The incidence rate and prevalence of glaucoma in Pakistan is similar to that of other dark - colored population countries. Primary trabeculectomy is still a preferred surgical approach. Diode laser is widely accepted as the therapy of choice in severe glaucoma cases. The purpose of this study was to deter-mine the role of Diode Laser Transscleral Cyclo-ablation as a primary surgical treatment option in Primary Open Angle Glaucoma after maximum tolerated medical therapy. This quasi - experimental study was con-ducted at Layton Rahmatullah Benevolent Trust Free Eye Care and Cancer Hospital, Lahore. Sixty patients fulfilling the inclusion criteria were selected from the Glaucoma unit for this study. 25 - 30 burns of Diode Laser were applied to 270 degrees avoiding 3 and 9 O clock positions, 1.5 mm posterior to the limbus. Laser was set at duration of 1 second and power between 1000 and 1500 mw. Patients were followed up for a period of one year. Results: Out of a total of 60 eyes with mean age 52.73 +- 7.40 years, 36 (60%) were male and 24 (40%) were female. The mean pre-operative Intra Ocular Pressure IOP was 41.0 +- 7.0 mmHg (The pre-operative IOP ranged from 28 mmHg to 60 mmHg). The mean post-operative IOP was 18.97 mmHg on day one, 16.75 mmHg at 1 week, 15.68 mmHg at 1 month, 15.00 mmHg at 6 months and by the end of a year it was about 14.15 mmHg (The post-operative IOP ranged from 6 mmHg to 52 mmHg). There was a significant drop of more than 50% of post-operative IOP as compared to pre-operative IOP. Conclusion: Diode Laser Transscleral Cycloablation is a practical, rapid, well - tolerated procedure that provides a significant lowering of intraocular pressure with few complications and can considered as alternative treatment in POAG if medical therapy fails. (author)

  10. An Experimental Determination of the Quasi-Rest Potential of Copper Indium Disulfide Utilizing the Novel Open-Circuit Voltage Transient

    Science.gov (United States)

    Newell, Michael Jason

    Environmental sustainability requires resource management that takes future generations into account. The present generation has witnessed changes across the planet, unprecedented in human history and disrupting communities and cities around the world, due to shifting global climate. This is primarily the result of fossil fuels, which powered modern civilization but dramatically increased levels of CO2 and other greenhouse gases, and may be the least sustainable aspect of human civilization. Chapter 1 justifies the research from an environmental perspective and provides initial research parameters. Thin film photovoltaic (PV) modules are reported the most sustainable among energy production technologies currently available. Electrodeposited PV layers offer significant improvement to sustainability metrics over current thin film production methods, at reduced cost, but have rarely been demonstrated on an industrial scale. Quasi-rest potential (QRP) ultimately led to large-scale, electrodeposited thin film CdTe modules. An in-situ material characterization technique that allows adjustment of the deposition voltage (Vdep) to match the exact experimental conditions, QRP enabled precise control of deposit stoichiometry and crystallinity. Chapter 2 discusses theory and literature regarding QRP, and introduces the open-circuit voltage transient (Voc T), developed by the present research for analyzing QRP as a function of both Vdep and time. VocT data from a CdTe ethylene glycol bath matches details and speculations from the literature. Although predicted to have wide applicability, experimental QRP data have never been published for compounds unrelated to CdTe. Chapter 3 discusses VocTs performed in pursuit of electrodeposited CuInS2, demonstrating functionality as a QRP scan in a variety of ethylene glycol solutions. Stoichiometries of deposited films were improved by using the V ocT to determine appropriate plating voltages. VocTs enabled QRP, in-situ rest potential (EM

  11. Investigation of the open-circuit voltage in wide-bandgap InGaP-host InP quantum dot intermediate-band solar cells

    Science.gov (United States)

    Aihara, Taketo; Tayagaki, Takeshi; Nagato, Yuki; Okano, Yoshinobu; Sugaya, Takeyoshi

    2018-04-01

    To analyze the open-circuit voltage (V oc) in intermediate-band solar cells, we investigated the current-voltage characteristics in wide-bandgap InGaP-based InP quantum dot (QD) solar cells. From the temperature dependence of the current-voltage curves, we show that the V oc in InP QD solar cells increases with decreasing temperature. We use a simple diode model to extract V oc at the zero-temperature limit, V 0, and the temperature coefficient C of the solar cells. Our results show that, while the C of InP QD solar cells is slightly larger than that of the reference InGaP solar cells, V 0 significantly decreases and coincides with the bandgap energy of the InP QDs rather than that of the InGaP host. This V 0 indicates that the V oc reduction in the InP QD solar cells is primarily caused by the breaking of the Fermi energy separation between the QDs and the host semiconductor in intermediate-band solar cells, rather than by enhanced carrier recombination.

  12. Finding the lost open-circuit voltage in polymer solar cells by UV-ozone treatment of the nickel acetate anode buffer layer.

    Science.gov (United States)

    Wang, Fuzhi; Sun, Gang; Li, Cong; Liu, Jiyan; Hu, Siqian; Zheng, Hua; Tan, Zhan'ao; Li, Yongfang

    2014-06-25

    Efficient polymer solar cells (PSCs) with enhanced open-circuit voltage (Voc) are fabricated by introducing solution-processed and UV-ozone (UVO)-treated nickel acetate (O-NiAc) as an anode buffer layer. According to X-ray photoelectron spectroscopy data, NiAc partially decomposed to NiOOH during the UVO treatment. NiOOH is a dipole species, which leads to an increase in the work function (as confirmed by ultraviolet photoemission spectroscopy), thus benefitting the formation of ohmic contact between the anode and photoactive layer and leading to increased Voc. In addition, the UVO treatment improves the wettability between the substrate and solvent of the active layer, which facilitates the formation of an upper photoactive layer with better morphology. Further, the O-NiAc layer can decrease the series resistance (Rs) and increase the parallel resistance (Rp) of the devices, inducing enhanced Voc in comparison with the as-prepared NiAc-buffered control devices without UVO treatment. For PSCs based on the P3HT:PCBM system, Voc increases from 0.50 to 0.60 V after the NiAc buffer layer undergoes UVO treatment. Similarly, in the P3HT:ICBA system, the Voc value of the device with a UVO-treated NiAc buffer layer increases from 0.78 to 0.88 V, showing an enhanced power conversion efficiency of 6.64%.

  13. Efficiency Evaluation of Five-Phase Outer-Rotor Fault-Tolerant BLDC Drives under Healthy and Open-Circuit Faulty Conditions

    Directory of Open Access Journals (Sweden)

    ARASHLOO, R. S.

    2014-05-01

    Full Text Available Fault tolerant motor drives are an interesting subject for many applications such as automotive industries and wind power generation. Among different configurations of these systems, five-phase BLDC drives are gaining more importance which is because of their compactness and high efficiency. Due to replacement of field windings by permanent magnets in their rotor structure, the main sources of power losses in these drives are iron (core losses, copper (winding losses, and inverter unit (semiconductor losses. Although low amplitude of power losses in five-phase BLDC drives is an important aspect for many applications, but their efficiency under faulty conditions is not considered in previous studies. In this paper, the efficiency of an outer-rotor five phase BLDC drive is evaluated under normal and different faulty conditions. Open-circuit fault is considered for one, two adjacent and two non-adjacent faulty phases. Iron core losses are calculated via FEM simulations in Flux-Cedrat software, and moreover, inverter losses and winding copper losses are simulated in MATLAB� environment. Experimental evaluations are conducted to evaluate the efficiency of the entire BLDC drive which verifies the theoretical developments.

  14. Simultaneous NOx and hydrocarbon emissions control for lean-burn engines using low-temperature solid oxide fuel cell at open circuit.

    Science.gov (United States)

    Huang, Ta-Jen; Hsu, Sheng-Hsiang; Wu, Chung-Ying

    2012-02-21

    The high fuel efficiency of lean-burn engines is associated with high temperature and excess oxygen during combustion and thus is associated with high-concentration NO(x) emission. This work reveals that very high concentration of NO(x) in the exhaust can be reduced and hydrocarbons (HCs) can be simultaneously oxidized using a low-temperature solid oxide fuel cell (SOFC). An SOFC unit is constructed with Ni-YSZ as the anode, YSZ as the electrolyte, and La(0.6)Sr(0.4)CoO(3) (LSC)-Ce(0.9)Gd(0.1)O(1.95) as the cathode, with or without adding vanadium to LSC. SOFC operation at 450 °C and open circuit can effectively treat NO(x) over the cathode at a very high concentration in the simulated exhaust. Higher NO(x) concentration up to 5000 ppm can result in a larger NO(x) to N(2) rate. Moreover, a higher oxygen concentration promotes NO conversion. Complete oxidation of HCs can be achieved by adding silver to the LSC current collecting layer. The SOFC-based emissions control system can treat NO(x) and HCs simultaneously, and can be operated without consuming the anode fuel (a reductant) at near the engine exhaust temperature to eliminate the need for reductant refilling and extra heating.

  15. Strategies for optimizing the opening of the outlet air circuit's nozzle to improve the efficiency of the PEMFC generator

    Energy Technology Data Exchange (ETDEWEB)

    Tirnovan, R. [Power Systems Department, Technical University of Cluj-Napoca (Romania); Giurgea, S.; Miraoui, A. [Fuel Cell Lab, University of Technology of Belfort-Montbeliard (France)

    2011-04-15

    The aim of this study is the optimal dimensioning of the air circuit's outlet nozzle in relation with the load duration curve, for a given PEMFC generator, in order to maximize the PEMFC efficiency and to increase the net outlet power. The steady state PEMFC operation has been taken into account. The model of the PEMFC system used in the work is based on a moving least squares technique. A centrifugal compressor has been taken into account, and the operating line of the compressor has been evaluated for an optimal fixed opening of the outlet nozzle. A multi-level optimization procedure has been implemented to solve the optimization problem. The developed algorithm is useful to design an optimum air subsystem, reducing the number of the control variables and the consequences of the dynamic behavior of a controlled electric adjustable valve on the PEMFC performance. The results of the work can contribute to the improvement of the PEMFC generator reliability and of its cost/performance ratio. (author)

  16. Possible central nervous system oxygen toxicity seizures among US recreational air or enriched air nitrox open circuit diving fatalities 2004-2013.

    Science.gov (United States)

    Buzzacott, P; Denoble, P J

    2017-01-01

    The first diver certification programme for recreational 'enriched air nitrox' (EAN) diving was released in 1985. Concerns were expressed that many EAN divers might suffer central nervous system (CNS) oxygen toxicity seizures and drown. US fatalities on open-circuit scuba occurring between 2004-2013, where the breathing gas was either air or EAN, were identified. Causes of death and preceding circumstances were examined by a medical examiner experienced in diving autopsies. Case notes were searched for witnessed seizures at elevated partial pressures of oxygen. The dataset comprised 344 air divers (86%) and 55 divers breathing EAN (14%). EAN divers' fatal dives were deeper than air divers' (28 msw vs 18 msw, p < 0.0001). Despite this, of the 249 cases where a cause of death was established, only three EAN divers were considered to have possibly died following CNS oxygen toxicity seizures at depth (ppO2 132, 142 and 193 kPa). The analysis of recreational diving fatalities in the US over 10 years found just one death likely from CNS oxygen toxicity among EAN divers. A further two possible, although unlikely, cases were also found. Fears of commonplace CNS oxygen toxicity seizures while EAN diving have not apparently been realized.

  17. An Open-Circuit Voltage and Power Conversion Efficiency Study of Fullerene Ternary Organic Solar Cells Based on Oligomer/Oligomer and Oligomer/Polymer.

    Science.gov (United States)

    Zhang, Guichuan; Zhou, Cheng; Sun, Chen; Jia, Xiaoe; Xu, Baomin; Ying, Lei; Huang, Fei; Cao, Yong

    2017-07-01

    Variations in the open-circuit voltage (V oc ) of ternary organic solar cells are systematically investigated. The initial study of these devices consists of two electron-donating oligomers, S2 (two units) and S7 (seven units), and the electron-accepting [6,6]-phenyl C71 butyric acid methyl ester (PC 71 BM) and reveals that the V oc is continuously tunable due to the changing energy of the charge transfer state (E ct ) of the active layers. Further investigation suggests that V oc is also continuously tunable upon change in E ct in a ternary blend system that consists of S2 and its corresponding polymer (P11):PC 71 BM. It is interesting to note that higher power conversion efficiencies can be obtained for both S2:S7:PC 71 BM and S2:P11:PC 71 BM ternary systems compared with their binary systems, which can be ascribed to an improved V oc due to the higher E ct and an improved fill factor due to the improved film morphology upon the incorporation of S2. These findings provide a new guideline for the future design of conjugated polymers for achieving higher performance of ternary organic solar cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Probing the Energy Level Alignment and the Correlation with Open-Circuit Voltage in Solution-Processed Polymeric Bulk Heterojunction Photovoltaic Devices.

    Science.gov (United States)

    Yang, Qing-Dan; Li, Ho-Wa; Cheng, Yuanhang; Guan, Zhiqiang; Liu, Taili; Ng, Tsz-Wai; Lee, Chun-Sing; Tsang, Sai-Wing

    2016-03-23

    Energy level alignment at the organic donor and acceptor interface is a key to determine the photovoltaic performance in organic solar cells, but direct probing of such energy alignment is still challenging especially for solution-processed bulk heterojunction (BHJ) thin films. Here we report a systematic investigation on probing the energy level alignment with different approaches in five commonly used polymer:[6,6]-phenyl-C71-butyric acid methyl ester (PCBM) BHJ systems. We find that by tuning the weight ratio of polymer to PCBM the electronic features from both polymer and PCBM can be obtained by photoemission spectroscopy. Using this approach, we find that some of the BHJ blends simply follow vacuum level alignment, but others show strong energy level shifting as a result of Fermi level pinning. Independently, by measuring the temperature-dependent open-circuit voltage (VOC), we find that the effective energy gap (Eeff), the energy difference between the highest occupied molecular orbital of the polymer donor (EHOMO-D) and lowest unoccupied molecular orbital of the PCBM acceptor (ELUMO-A), obtained by photoemission spectroscopy in all polymer:PCBM blends has an excellent agreement with the extrapolated VOC at 0 K. Consequently, the photovoltage loss of various organic BHJ photovoltaic devices at room temperature is in a range of 0.3-0.6 V. It is believed that the demonstrated direct measurement approach of the energy level alignment in solution-processed organic BHJ will bring deeper insight into the origin of the VOC and the corresponding photovoltage loss mechanism in organic photovoltaic cells.

  19. Enhancement of open-circuit voltage and the fill factor in CdTe nanocrystal solar cells by using interface materials

    International Nuclear Information System (INIS)

    Zhu, Jiaoyan; Yang, Yuehua; Gao, Yuping; Qin, Donghuan; Wu, Hongbin; Huang, Wenbo; Hou, Lintao

    2014-01-01

    Interface states influence the operation of nanocrystal (NC) solar cell carrier transport, recombination and energetic mechanisms. In a typical CdTe NC solar cell with a normal structure of a ITO/p-CdTe NCs/n-acceptor (or without)/Al configuration, the contact between the ITO and CdTe is a non-ohm contact due to a different work function (for an ITO, the value is ∼4.7 eV, while for CdTe NCs, the value is ∼5.3 eV), which results in an energetic barrier at the ITO/CdTe interface and decreases the performance of the NC solar cells. This work investigates how interface materials (including Au, MoO x and C 60 ) affect the performance of NC solar cells. It is found that devices with interface materials have shown higher V oc than those without interface materials. For the case in which we used Au as an interface, we obtained a high open-circuit voltage of 0.65 V, coupled with a high fill factor (62%); this resulted in a higher energy conversion efficiency (ECE) of 5.3%, which showed a 30% increase in the ECE compared with those without the interlayer. The capacitance measurements indicate that the increased V oc in the case in which Au was used as the interface is likely due to good ohm contact between the Au’s and the CdTe NCs’ thin film, which decreases the energetic barrier at the ITO/CdTe interface. (paper)

  20. Efficient Planar Structured Perovskite Solar Cells with Enhanced Open-Circuit Voltage and Suppressed Charge Recombination Based on a Slow Grown Perovskite Layer from Lead Acetate Precursor.

    Science.gov (United States)

    Li, Cong; Guo, Qiang; Wang, Zhibin; Bai, Yiming; Liu, Lin; Wang, Fuzhi; Zhou, Erjun; Hayat, Tasawar; Alsaedi, Ahmed; Tan, Zhan'ao

    2017-12-06

    For planar structured organic-inorganic hybrid perovskite solar cells (PerSCs) with the poly(3,4-ethylenedioxythiophene:polystyrene sulfonate) (PEDOT:PSS) hole transport layer, the open-circuit voltage (V oc ) of the device is limited to be about 1.0 V, resulting in inferior performance in comparison with TiO 2 -based planar counterparts. Therefore, increasing V oc of the PEDOT:PSS-based planar device is an important way to enhance the efficiency of the PerSCs. Herein, we demonstrate a novel approach for perovskite film formation and the film is formed by slow growth from lead acetate precursor via a one-step spin-coating process without the thermal annealing (TA) process. Because the perovskite layer grows slowly and naturally, high-quality perovskite film can be achieved with larger crystalline particles, less defects, and smoother surface morphology. Ultraviolet absorption, X-ray diffraction, scanning electron microscopy, steady-state fluorescence spectroscopy (photoluminescence), and time-resolved fluorescence spectroscopy are used to clarify the crystallinity, morphology, and internal defects of perovskite thin films. The power conversion efficiency of p-i-n PerSCs based on slow-grown film (16.33%) shows greatly enhanced performance compared to that of the control device based on traditional thermally annealed perovskite film (14.33%). Furthermore, the V oc of the slow-growing device reaches 1.12 V, which is 0.1 V higher than that of the TA device. These findings indicate that slow growth of the perovskite layer from lead acetate precursor is a promising approach to achieve high-quality perovskite film for high-performance PerSCs.

  1. Peak reading detector circuit

    International Nuclear Information System (INIS)

    Courtin, E.; Grund, K.; Traub, S.; Zeeb, H.

    1975-01-01

    The peak reading detector circuit serves for picking up the instants during which peaks of a given polarity occur in sequences of signals in which the extreme values, their time intervals, and the curve shape of the signals vary. The signal sequences appear in measuring the foetal heart beat frequence from amplitude-modulated ultrasonic, electrocardiagram, and blood pressure signals. In order to prevent undesired emission of output signals from, e. g., disturbing intermediate extreme values, the circuit consists of the series connections of a circuit to simulate an ideal diode, a strong unit, a discriminator for the direction of charging current, a time-delay circuit, and an electronic switch lying in the decharging circuit of the storage unit. The time-delay circuit thereby causes storing of a preliminary maximum value being used only after a certain time delay for the emission of the output signal. If a larger extreme value occurs during the delay time the preliminary maximum value is cleared and the delay time starts running anew. (DG/PB) [de

  2. Accident analysis of railway transportation of low-level radioactive and hazardous chemical wastes: Application of the /open quotes/Maximum Credible Accident/close quotes/ concept

    Energy Technology Data Exchange (ETDEWEB)

    Ricci, E.; McLean, R.B.

    1988-09-01

    The maximum credible accident (MCA) approach to accident analysis places an upper bound on the potential adverse effects of a proposed action by using conservative but simplifying assumptions. It is often used when data are lacking to support a more realistic scenario or when MCA calculations result in acceptable consequences. The MCA approach can also be combined with realistic scenarios to assess potential adverse effects. This report presents a guide for the preparation of transportation accident analyses based on the use of the MCA concept. Rail transportation of contaminated wastes is used as an example. The example is the analysis of the environmental impact of the potential derailment of a train transporting a large shipment of wastes. The shipment is assumed to be contaminated with polychlorinated biphenyls and low-level radioactivities of uranium and technetium. The train is assumed to plunge into a river used as a source of drinking water. The conclusions from the example accident analysis are based on the calculation of the number of foreseeable premature cancer deaths the might result as a consequence of this accident. These calculations are presented, and the reference material forming the basis for all assumptions and calculations is also provided.

  3. Accident analysis of railway transportation of low-level radioactive and hazardous chemical wastes: Application of the /open quotes/Maximum Credible Accident/close quotes/ concept

    International Nuclear Information System (INIS)

    Ricci, E.; McLean, R.B.

    1988-09-01

    The maximum credible accident (MCA) approach to accident analysis places an upper bound on the potential adverse effects of a proposed action by using conservative but simplifying assumptions. It is often used when data are lacking to support a more realistic scenario or when MCA calculations result in acceptable consequences. The MCA approach can also be combined with realistic scenarios to assess potential adverse effects. This report presents a guide for the preparation of transportation accident analyses based on the use of the MCA concept. Rail transportation of contaminated wastes is used as an example. The example is the analysis of the environmental impact of the potential derailment of a train transporting a large shipment of wastes. The shipment is assumed to be contaminated with polychlorinated biphenyls and low-level radioactivities of uranium and technetium. The train is assumed to plunge into a river used as a source of drinking water. The conclusions from the example accident analysis are based on the calculation of the number of foreseeable premature cancer deaths the might result as a consequence of this accident. These calculations are presented, and the reference material forming the basis for all assumptions and calculations is also provided

  4. Resonance circuits for adiabatic circuits

    Directory of Open Access Journals (Sweden)

    C. Schlachta

    2003-01-01

    Full Text Available One of the possible techniques to reduces the power consumption in digital CMOS circuits is to slow down the charge transport. This slowdown can be achieved by introducing an inductor in the charging path. Additionally, the inductor can act as an energy storage element, conserving the energy that is normally dissipated during discharging. Together with the parasitic capacitances from the circuit a LCresonant circuit is formed.

  5. Time to reach tacrolimus maximum blood concentration,mean residence time, and acute renal allograft rejection: an open-label, prospective, pharmacokinetic study in adult recipients.

    Science.gov (United States)

    Kuypers, Dirk R J; Vanrenterghem, Yves

    2004-11-01

    The aims of this study were to determine whether disposition-related pharmacokinetic parameters such as T(max) and mean residence time (MRT) could be used as predictors of clinical efficacy of tacrolimus in renal transplant recipients, and to what extent these parameters would be influenced by clinical variables. We previously demonstrated, in a prospective pharmacokinetic study in de novo renal allograft recipients, that patients who experienced early acute rejection did not differ from patients free from rejection in terms of tacrolimus pharmacokinetic exposure parameters (dose interval AUC, preadministration trough blood concentration, C(max), dose). However, recipients with acute rejection reached mean (SD) tacrolimus T(max) significantly faster than those who were free from rejection (0.96 [0.56] hour vs 1.77 [1.06] hours; P clearance nor T(1/2) could explain this unusual finding, we used data from the previous study to calculate MRT from the concentration-time curves. As part of the previous study, 100 patients (59 male, 41 female; mean [SD] age, 51.4 [13.8] years;age range, 20-75 years) were enrolled in the study The calculated MRT was significantly shorter in recipients with acute allograft rejection (11.32 [031] hours vs 11.52 [028] hours; P = 0.02), just like T(max) was an independent risk factor for acute rejection in a multivariate logistic regression model (odds ratio, 0.092 [95% CI, 0.014-0.629]; P = 0.01). Analyzing the impact of demographic, transplantation-related, and biochemical variables on MRT, we found that increasing serum albumin and hematocrit concentrations were associated with a prolonged MRT (P calculated MRT were associated with a higher incidence of early acute graft rejection. These findings suggest that a shorter transit time of tacrolimus in certain tissue compartments, rather than failure to obtain a maximum absolute tacrolimus blood concentration, might lead to inadequate immunosuppression early after transplantation.

  6. Electronic circuit encyclopedia 2

    International Nuclear Information System (INIS)

    Park, Sun Ho

    1992-10-01

    This book is composed of 15 chapters, which are amplification of weak signal and measurement circuit audio control and power amplification circuit, data transmission and wireless system, forwarding and isolation, signal converting circuit, counter and comparator, discriminator circuit, oscillation circuit and synthesizer, digital and circuit on computer image processing circuit, sensor drive circuit temperature sensor circuit, magnetic control and application circuit, motor driver circuit, measuring instrument and check tool and power control and stability circuit.

  7. Electronic circuit encyclopedia 2

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Ho

    1992-10-15

    This book is composed of 15 chapters, which are amplification of weak signal and measurement circuit audio control and power amplification circuit, data transmission and wireless system, forwarding and isolation, signal converting circuit, counter and comparator, discriminator circuit, oscillation circuit and synthesizer, digital and circuit on computer image processing circuit, sensor drive circuit temperature sensor circuit, magnetic control and application circuit, motor driver circuit, measuring instrument and check tool and power control and stability circuit.

  8. Three-Dimensional Simulation of Plasma Deformation During Contact Opening in a Circuit Breaker, Including the Analysis of Kink Instability and Sausage Instability

    International Nuclear Information System (INIS)

    Abbasi, Vahid; Gholami, Ahmad; Niayesh, Kaveh

    2012-01-01

    A three-dimensional (3-D) transient model has been developed to investigate plasma deformation driven by a magnetic field and its influence on arc stability in a circuit breaker. The 3-D distribution of electric current density is obtained from a current continuity equation along with the generalized Ohm's law; while the magnetic field induced by the current flowing through the arc column is calculated by the magnetic vector potential equation. When gas interacts with an arc column, fundamental factors, such as Ampere's law, Ohm's law, the turbulence model, transport equations of mass, momentum and energy of plasma flow, have to be coupled for analyzing the phenomenon. The coupled interactions between arc and plasma flow are described in the framework of time-dependent magnetohydrodynamic (MHD) equations in conjunction with a K-ε turbulence model. Simulations have been focused on sausage and kink instabilities in plasma (these phenomena are related to pinch effects and electromagnetic fields). The 3-D simulation reveals the relation between plasma deformation and instability phenomena, which affect arc stability during circuit breaker operation. Plasma deformation is the consequence of coupled interactions between the electromagnetic force and plasma flow described in simulations. (plasma technology)

  9. ECCS control circuit

    International Nuclear Information System (INIS)

    Sato, Takashi.

    1986-01-01

    Purpose: To afford a sufficient margin to pressure vibrations upon starting of an automatic depressurization system by dispersing pressure vibration in suppression water due to the opening action of an automatic releaf valve in the automatic depressurization system thereby reducing the dynamic load exerted to the surface of the suppression walls. Constitution: Upon occurrence of loss of coolant accidents, an automatic releaf valve for automatic depressurization is opened to deliver the steams in the pressure vessel into the suppression pool. Since a plurality of automatic releaf valves have usually been disposed, if they are opened simultaneously, excess dynamic loads are exerted due to the pressure vibrations to the wall surface of the suppression pool. In this invention, a control circuit is disposed such that the opening timing for each of the automatic releaf valves is deviated upon occurrence of a driving signal for the automatic depressurization system to thereby disperse the pressure vibrations in the suppression water. (Kamimura, M.)

  10. Controllable circuit

    DEFF Research Database (Denmark)

    2010-01-01

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

  11. Circuit Training.

    Science.gov (United States)

    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)

  12. Polypyrrole: FeOx·ZnO nanoparticle solar cells with breakthrough open-circuit voltage prepared from relatively stable liquid dispersions

    KAUST Repository

    Zong, Baoyu; Ho, Pin; Zhang, Zhiguo; Ng, Gingmeng; Yao, Kui; Guo, Zaibing

    2014-01-01

    in open air from relatively stable liquid dark-color polypyrrole-based dispersions, which were synthesized using appropriate surfactants during the in situ polymerization of pyrrole with FeCl3 or both H2O2 and FeCl3 as the oxidizers. The performance

  13. Rational Design of High-Performance Wide-Bandgap (≈2 eV) Polymer Semiconductors as Electron Donors in Organic Photovoltaics Exhibiting High Open Circuit Voltages (≈1 V).

    Science.gov (United States)

    Chochos, Christos L; Katsouras, Athanasios; Gasparini, Nicola; Koulogiannis, Chrysanthos; Ameri, Tayebeh; Brabec, Christoph J; Avgeropoulos, Apostolos

    2017-01-01

    Systematic optimization of the chemical structure of wide-bandgap (≈2.0 eV) "donor-acceptor" copolymers consisting of indacenodithiophene or indacenodithieno[3,2-b]thiophene as the electron-rich unit and thieno[3,4-c]pyrrole-4,6-dione as the electron-deficient moiety in terms of alkyl side chain engineering and distance of the electron-rich and electron-deficient monomers within the repeat unit of the polymer chain results in high-performance electron donor materials for organic photovoltaics. Specifically, preliminary results demonstrate extremely high open circuit voltages (V oc s) of ≈1.0 V, reasonable short circuit current density (J sc ) of around 11 mA cm -2 , and moderate fill factors resulting in efficiencies close to 6%. All the devices are fabricated in an inverted architecture with the photoactive layer processed by doctor blade equipment, showing the compatibility with roll-to-roll large-scale manufacturing processes. From the correlation of the chemical structure-optoelectronic properties-photovoltaic performance, a rational guide toward further optimization of the chemical structure in this family of copolymers, has been achieved. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Photovoltaic Small Molecules of TPA(FxBT-T-Cz)3: Tuning Open-Circuit Voltage over 1.0 V for Their Organic Solar Cells by Increasing Fluorine Substitution.

    Science.gov (United States)

    Wang, Qiong; Duan, Linrui; Tao, Qiang; Peng, Wenhong; Chen, Jianhua; Tan, Hua; Yang, Renqiang; Zhu, Weiguo

    2016-11-09

    To simultaneously improve both open-circuit voltage (V oc ) and short-circuit current density (J sc ) for organic solar cells, a novel D(A-π-Ar) 3 type of photovoltaic small molecules of TPA(F x BT-T-3Cz) 3 was designed and synthesized, which contain central triphenylamine (TPA), terminal carbazole (Cz), armed fluorine-substituted benzothiadiazole (F x BT, where x = 1 or 2), and bridged thiophene (T) units. A narrowed ultraviolet-visible absorption and a decreasing highest occupied molecular orbital energy level were observed from TPA(F 1 BT-T-3Cz) 3 to TPA(F 2 BT-T-3Cz) 3 with increasing fluorine substitution. However, the TPA(F 2 BT-T-3Cz) 3 /PC 71 BM-based solar devices showed a rising V oc of 1.01 V and an enhanced J sc of 10.84 mA cm -2 as well as a comparable power conversion efficiency of 4.81% in comparison to the TPA(F 1 BT-T-3Cz) 3 /PC 71 BM-based devices. Furthermore, in comparison to the parent TPA(BT-T-3Cz) 3 molecule without fluorine substitution, the fluorine-substituted TPA(F x BT-T-3Cz) 3 molecules exhibited significantly incremental V oc and J sc values in their bulk heterojunction organic solar cells, owing to fluorine incorporation in the electron-deficient benzothiadiazole unit.

  15. PUZZLE - A program for computer-aided design of printed circuit artwork

    Science.gov (United States)

    Harrell, D. A. W.; Zane, R.

    1971-01-01

    Program assists in solving spacing problems encountered in printed circuit /PC/ design. It is intended to have maximum use for two-sided PC boards carrying integrated circuits, and also aids design of discrete component circuits.

  16. Open Circuit Potential Changes upon Protonation/Deprotonation of ω-Functionalized Alkanethiols on Au: Determination of Surface pK {sub 1/2} in Aqueous and Non-Aqueous System

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Seung Ryul; Park, Kyung Soon; Jang, Jae Won; Hwang, Seong Pil [Korea Univ., Sejong (Korea, Republic of)

    2016-09-15

    The controlled assembly of functional nanomaterials has been drawing significant interest for making devices by integration of nanomaterials. The building blocks of functional nanomaterials might be confined spatially on the chemically patterned surface through both covalent and non-covalent bonds. Potentiometric measurement is affordable technique for various researchers because it requires only voltmeter and reference electrode. Moreover, it can be applied to various polar solvent such as methanol and ethanol. The open circuit potential (OCP) is measured indicating the potential difference between reference electrode and working electrode. The potential of working electrode might be affected by redox chemical reaction and charge state/separation. Our results provide the simple and affordable method to investigate pK {sub 1/2} of thin film both in aqueous phase and in non-aqueous phase, which has significant role in colloidal chemistry, nanochemistry, surface chemistry, electrochemistry, and others.

  17. Relationship between open-circuit voltage in Cu(In,Ga)Se{sub 2} solar cell and peak position of (220/204) preferred orientation near its absorber surface

    Energy Technology Data Exchange (ETDEWEB)

    Chantana, J., E-mail: jakapan@fc.ritsumei.ac.jp; Minemoto, T. [Department of Electrical and Electronic Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Watanabe, T.; Teraji, S.; Kawamura, K. [Environment and Energy Research Center, Nitto Denko Corporation, 2-8 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2013-11-25

    Cu(In,Ga)Se{sub 2} (CIGS) absorbers with various Ga/III, Ga/(In+Ga), profiles are prepared by the so-called “multi-layer precursor method” using multi-layer co-evaporation of material sources. It is revealed that open-circuit voltage (V{sub OC}) of CIGS solar cell is primarily dependent on averaged Ga/III near the surface of its absorber. This averaged Ga/III is well predicted by peak position of (220/204) preferred orientation of CIGS film near its surface investigated by glancing-incidence X-ray diffraction with 0.1° incident angle. Finally, the peak position of (220/204) preferred orientation is proposed as a measure of V{sub OC} before solar cell fabrication.

  18. Effect of the depth base along the vertical on the electrical parameters of a vertical parallel silicon solar cell in open and short circuit

    Science.gov (United States)

    Sahin, Gokhan; Kerimli, Genber

    2018-03-01

    This article presented a modeling study of effect of the depth base initiating on vertical parallel silicon solar cell's photovoltaic conversion efficiency. After the resolution of the continuity equation of excess minority carriers, we calculated the electrical parameters such as the photocurrent density, the photovoltage, series resistance and shunt resistances, diffusion capacitance, electric power, fill factor and the photovoltaic conversion efficiency. We determined the maximum electric power, the operating point of the solar cell and photovoltaic conversion efficiency according to the depth z in the base. We showed that the photocurrent density decreases with the depth z. The photovoltage decreased when the depth base increases. Series and shunt resistances were deduced from electrical model and were influenced and the applied the depth base. The capacity decreased with the depth z of the base. We had studied the influence of the variation of the depth z on the electrical parameters in the base.

  19. F-Paris: integrated electronic circuits [Tender

    CERN Multimedia

    2003-01-01

    "Fourniture, montage et tests des circuits imprimes et modules multi composants pour le trajectographe central de CMS. Maximum de 12 000 circuits imprimes et modules multi-composants necessaires au trajectographe central de l'experience CMS aupres du Large Hadron Collider" (1 page).

  20. Adjustable direct current and pulsed circuit fault current limiter

    Science.gov (United States)

    Boenig, Heinrich J.; Schillig, Josef B.

    2003-09-23

    A fault current limiting system for direct current circuits and for pulsed power circuit. In the circuits, a current source biases a diode that is in series with the circuits' transmission line. If fault current in a circuit exceeds current from the current source biasing the diode open, the diode will cease conducting and route the fault current through the current source and an inductor. This limits the rate of rise and the peak value of the fault current.

  1. LOGIC CIRCUIT

    Science.gov (United States)

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

    1963-12-24

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

  2. Short- circuit tests of circuit breakers

    OpenAIRE

    Chorovský, P.

    2015-01-01

    This paper deals with short-circuit tests of low voltage electrical devices. In the first part of this paper, there are described basic types of short- circuit tests and their principles. Direct and indirect (synthetic) tests with more details are described in the second part. Each test and principles are explained separately. Oscilogram is obtained from short-circuit tests of circuit breakers at laboratory. The aim of this research work is to propose a test circuit for performing indirect test.

  3. Collective of mechatronics circuit

    International Nuclear Information System (INIS)

    1987-02-01

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

  4. Collective of mechatronics circuit

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1987-02-15

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

  5. Textbook Error: Short Circuiting on Electrochemical Cell

    Science.gov (United States)

    Bonicamp, Judith M.; Clark, Roy W.

    2007-01-01

    Short circuiting an electrochemical cell is an unreported but persistent error in the electrochemistry textbooks. It is suggested that diagrams depicting a cell delivering usable current to a load be postponed, the theory of open-circuit galvanic cells is explained, the voltages from the tables of standard reduction potentials is calculated and…

  6. Circuit parties.

    Science.gov (United States)

    Guzman, R

    2000-03-01

    Circuit parties are extended celebrations, lasting from a day to a week, primarily attended by gay and bisexual men in their thirties and forties. These large-scale dance parties move from city to city and draw thousands of participants. The risks for contracting HIV during these parties include recreational drug use and unsafe sex. Limited data exists on the level of risk at these parties, and participants are skeptical of outside help because of past criticism of these events. Health care and HIV advocates can promote risk-reduction strategies with the cooperation of party planners and can counsel individuals to personally reduce their own risk. To convey the message, HIV prevention workers should emphasize positive and community-centered aspects of the parties, such as taking care of friends and avoiding overdose.

  7. Basic electronic circuits

    CERN Document Server

    Buckley, P M

    1980-01-01

    In the past, the teaching of electricity and electronics has more often than not been carried out from a theoretical and often highly academic standpoint. Fundamentals and basic concepts have often been presented with no indication of their practical appli­ cations, and all too frequently they have been illustrated by artificially contrived laboratory experiments bearing little relationship to the outside world. The course comes in the form of fourteen fairly open-ended constructional experiments or projects. Each experiment has associated with it a construction exercise and an explanation. The basic idea behind this dual presentation is that the student can embark on each circuit following only the briefest possible instructions and that an open-ended approach is thereby not prejudiced by an initial lengthy encounter with the theory behind the project; this being a sure way to dampen enthusiasm at the outset. As the investigation progresses, questions inevitably arise. Descriptions of the phenomena encounte...

  8. Electronic logic to enhance switch reliability in detecting openings and closures of redundant switches

    Science.gov (United States)

    Cooper, James A.

    1986-01-01

    A logic circuit is used to enhance redundant switch reliability. Two or more switches are monitored for logical high or low output. The output for the logic circuit produces a redundant and failsafe representation of the switch outputs. When both switch outputs are high, the output is high. Similarly, when both switch outputs are low, the logic circuit's output is low. When the output states of the two switches do not agree, the circuit resolves the conflict by memorizing the last output state which both switches were simultaneously in and produces the logical complement of this output state. Thus, the logic circuit of the present invention allows the redundant switches to be treated as if they were in parallel when the switches are open and as if they were in series when the switches are closed. A failsafe system having maximum reliability is thereby produced.

  9. Integrated Reconfigurable High-Voltage Transmitting Circuit for CMUTs

    DEFF Research Database (Denmark)

    Llimos Muntal, Pere; Larsen, Dennis Øland; Jørgensen, Ivan Harald Holger

    2014-01-01

    -out and measurements are performed on the integrated circuit. The transmitting circuit is reconfigurable externally making it able to drive a wide variety of CMUTs. The transmitting circuit can generate several pulse shapes, pulse voltages up to 100 V, maximum pulse range of 50 V and frequencies up to 5 MHz. The area...

  10. Uninterrupted thermoelectric energy harvesting using temperature-sensor-based maximum power point tracking system

    International Nuclear Information System (INIS)

    Park, Jae-Do; Lee, Hohyun; Bond, Matthew

    2014-01-01

    Highlights: • Feedforward MPPT scheme for uninterrupted TEG energy harvesting is suggested. • Temperature sensors are used to avoid current measurement or source disconnection. • MPP voltage reference is generated based on OCV vs. temperature differential model. • Optimal operating condition is maintained using hysteresis controller. • Any type of power converter can be used in the proposed scheme. - Abstract: In this paper, a thermoelectric generator (TEG) energy harvesting system with a temperature-sensor-based maximum power point tracking (MPPT) method is presented. Conventional MPPT algorithms for photovoltaic cells may not be suitable for thermoelectric power generation because a significant amount of time is required for TEG systems to reach a steady state. Moreover, complexity and additional power consumption in conventional circuits and periodic disconnection of power source are not desirable for low-power energy harvesting applications. The proposed system can track the varying maximum power point (MPP) with a simple and inexpensive temperature-sensor-based circuit without instantaneous power measurement or TEG disconnection. This system uses TEG’s open circuit voltage (OCV) characteristic with respect to temperature gradient to generate a proper reference voltage signal, i.e., half of the TEG’s OCV. The power converter controller maintains the TEG output voltage at the reference level so that the maximum power can be extracted for the given temperature condition. This feedforward MPPT scheme is inherently stable and can be implemented without any complex microcontroller circuit. The proposed system has been validated analytically and experimentally, and shows a maximum power tracking error of 1.15%

  11. Maximum likelihood positioning for gamma-ray imaging detectors with depth of interaction measurement

    International Nuclear Information System (INIS)

    Lerche, Ch.W.; Ros, A.; Monzo, J.M.; Aliaga, R.J.; Ferrando, N.; Martinez, J.D.; Herrero, V.; Esteve, R.; Gadea, R.; Colom, R.J.; Toledo, J.; Mateo, F.; Sebastia, A.; Sanchez, F.; Benlloch, J.M.

    2009-01-01

    The center of gravity algorithm leads to strong artifacts for gamma-ray imaging detectors that are based on monolithic scintillation crystals and position sensitive photo-detectors. This is a consequence of using the centroids as position estimates. The fact that charge division circuits can also be used to compute the standard deviation of the scintillation light distribution opens a way out of this drawback. We studied the feasibility of maximum likelihood estimation for computing the true gamma-ray photo-conversion position from the centroids and the standard deviation of the light distribution. The method was evaluated on a test detector that consists of the position sensitive photomultiplier tube H8500 and a monolithic LSO crystal (42mmx42mmx10mm). Spatial resolution was measured for the centroids and the maximum likelihood estimates. The results suggest that the maximum likelihood positioning is feasible and partially removes the strong artifacts of the center of gravity algorithm.

  12. Maximum likelihood positioning for gamma-ray imaging detectors with depth of interaction measurement

    Energy Technology Data Exchange (ETDEWEB)

    Lerche, Ch.W. [Grupo de Sistemas Digitales, ITACA, Universidad Politecnica de Valencia, 46022 Valencia (Spain)], E-mail: lerche@ific.uv.es; Ros, A. [Grupo de Fisica Medica Nuclear, IFIC, Universidad de Valencia-Consejo Superior de Investigaciones Cientificas, 46980 Paterna (Spain); Monzo, J.M.; Aliaga, R.J.; Ferrando, N.; Martinez, J.D.; Herrero, V.; Esteve, R.; Gadea, R.; Colom, R.J.; Toledo, J.; Mateo, F.; Sebastia, A. [Grupo de Sistemas Digitales, ITACA, Universidad Politecnica de Valencia, 46022 Valencia (Spain); Sanchez, F.; Benlloch, J.M. [Grupo de Fisica Medica Nuclear, IFIC, Universidad de Valencia-Consejo Superior de Investigaciones Cientificas, 46980 Paterna (Spain)

    2009-06-01

    The center of gravity algorithm leads to strong artifacts for gamma-ray imaging detectors that are based on monolithic scintillation crystals and position sensitive photo-detectors. This is a consequence of using the centroids as position estimates. The fact that charge division circuits can also be used to compute the standard deviation of the scintillation light distribution opens a way out of this drawback. We studied the feasibility of maximum likelihood estimation for computing the true gamma-ray photo-conversion position from the centroids and the standard deviation of the light distribution. The method was evaluated on a test detector that consists of the position sensitive photomultiplier tube H8500 and a monolithic LSO crystal (42mmx42mmx10mm). Spatial resolution was measured for the centroids and the maximum likelihood estimates. The results suggest that the maximum likelihood positioning is feasible and partially removes the strong artifacts of the center of gravity algorithm.

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

    Science.gov (United States)

    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. Copyright © 2016. Published by Elsevier B.V.

  14. Maximum Water Hammer Sensitivity Analysis

    OpenAIRE

    Jalil Emadi; Abbas Solemani

    2011-01-01

    Pressure waves and Water Hammer occur in a pumping system when valves are closed or opened suddenly or in the case of sudden failure of pumps. Determination of maximum water hammer is considered one of the most important technical and economical items of which engineers and designers of pumping stations and conveyance pipelines should take care. Hammer Software is a recent application used to simulate water hammer. The present study focuses on determining significance of ...

  15. Analog circuit design designing dynamic circuit response

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    This second volume, Designing Dynamic Circuit Response builds upon the first volume Designing Amplifier Circuits by extending coverage to include reactances and their time- and frequency-related behavioral consequences.

  16. Trigger circuit

    International Nuclear Information System (INIS)

    Verity, P.R.; Chaplain, M.D.; Turner, G.D.J.

    1984-01-01

    A monostable trigger circuit comprises transistors TR2 and TR3 arranged with their collectors and bases interconnected. The collector of the transistor TR2 is connected to the base of transistor TR3 via a capacitor C2 the main current path of a grounded base transistor TR1 and resistive means R2,R3. The collector of transistor TR3 is connected to the base of transistor TR2 via resistive means R6, R7. In the stable state all the transistors are OFF, the capacitor C2 is charged, and the output is LOW. A positive pulse input to the base of TR2 switches it ON, which in turn lowers the voltage at points A and B and so switches TR1 ON so that C2 can discharge via R2, R3, which in turn switches TR3 ON making the output high. Thus all three transistors are latched ON. When C2 has discharged sufficiently TR1 switches OFF, followed by TR3 (making the output low again) and TR2. The components C1, C3 and R4 serve to reduce noise, and the diode D1 is optional. (author)

  17. Approximate maximum parsimony and ancestral maximum likelihood.

    Science.gov (United States)

    Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

    2010-01-01

    We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

  18. Electron-deficient N-alkyloyl derivatives of thieno[3,4-c]pyrrole-4,6-dione yield efficient polymer solar cells with open-circuit voltages > 1 v

    KAUST Repository

    Warnan, Julien

    2014-05-13

    Poly(benzo[1,2-b:4,5-b′]dithiophene-thieno[3,4-c]pyrrole-4,6-dione) (PBDTTPD) polymer donors yield some of the highest open-circuit voltages (V OC, ca. 0.9 V) and fill factors (FF, ca. 70%) in conventional bulk-heterojunction (BHJ) solar cells with PCBM acceptors. Recent work has shown that the incorporation of ring substituents into the side chains of the BDT motifs in PBDTTPD can induce subtle variations in material properties, resulting in an increase of the BHJ device VOC to ∼1 V. In this contribution, we report on the synthesis of N-alkyloyl-substituted TPD motifs (TPD(CO)) and show that the electron-deficient motifs can further lower both the polymer LUMO and HOMO levels, yielding device VOC > 1 V (up to ca. 1.1 V) in BHJ solar cells with PCBM. Despite the high VOC achieved (i.e., low polymer HOMO), BHJ devices cast from TPD(CO)-based polymer donors can reach power conversion efficiencies (PCEs) of up to 6.7%, making these promising systems for use in the high-band-gap cell of tandem solar cells. © 2014 American Chemical Society.

  19. Dependence of open-circuit voltage of SnO2-nSi solar cells; SnO2-nSi taiyo denchi no sanka ondo menhoi izonsei

    Energy Technology Data Exchange (ETDEWEB)

    Shinoda, S; Shimizu, A; Yano, K; Kasuga, M [Yamanashi University, Yamanashi (Japan). Faculty of Engineering

    1997-11-25

    Although metal(or semiconductor)-semiconductor solar cells, SnO2-nSi solar cell for example, are superior in cost and efficiency, its barrier height and open-circuit voltage V(oc) are lower than those of p-n junctions. To improve these defects, study was made on the dependence of V(oc) on oxidation temperature and surface orientation using various solar cells prepared from (100)Si and (111)Si under various oxidation conditions. As a result, the density of surface states increases with a decrease in oxidation temperature of Si substrates, resulting in an increase in diode factor and V(oc). In this case, since oxide films are extremely thin and contribution of non-terminated bonds is large in the initial oxidation stage, the quantity of dangling bonds is larger in (100) plane than (111) plane, resulting in an increase in diode factor and V(oc). Since the surface energy level (the degree of electrons dominated by acceptor-like surface state from this level to the top of a valence band) of (100) Si is lower than that of (111) Si, the effective barrier height and V(oc) increase. 28 refs., 6 figs., 2 tabs.

  20. Maximum permissible dose

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

  1. Design of an improved RCD buffer circuit for full bridge circuit

    Science.gov (United States)

    Yang, Wenyan; Wei, Xueye; Du, Yongbo; Hu, Liang; Zhang, Liwei; Zhang, Ou

    2017-05-01

    In the full bridge inverter circuit, when the switch tube suddenly opened or closed, the inductor current changes rapidly. Due to the existence of parasitic inductance of the main circuit. Therefore, the surge voltage between drain and source of the switch tube can be generated, which will have an impact on the switch and the output voltage. In order to ab sorb the surge voltage. An improve RCD buffer circuit is proposed in the paper. The peak energy will be absorbed through the buffer capacitor of the circuit. The part energy feedback to the power supply, another part release through the resistor in the form of heat, and the circuit can absorb the voltage spikes. This paper analyzes the process of the improved RCD snubber circuit, According to the specific parameters of the main circuit, a reasonable formula for calculating the resistance capacitance is given. A simulation model will be modulated in Multisim, which compared the waveform of tube voltage and the output waveform of the circuit without snubber circuit with the improved RCD snubber circuit. By comparing and analyzing, it is proved that the improved buffer circuit can absorb surge voltage. Finally, experiments are demonstrated to validate that the correctness of the RC formula and the improved RCD snubber circuit.

  2. Improvement of maximum power point tracking perturb and observe algorithm for a standalone solar photovoltaic system

    International Nuclear Information System (INIS)

    Awan, M.M.A.; Awan, F.G.

    2017-01-01

    Extraction of maximum power from PV (Photovoltaic) cell is necessary to make the PV system efficient. Maximum power can be achieved by operating the system at MPP (Maximum Power Point) (taking the operating point of PV panel to MPP) and for this purpose MPPT (Maximum Power Point Trackers) are used. There are many tracking algorithms/methods used by these trackers which includes incremental conductance, constant voltage method, constant current method, short circuit current method, PAO (Perturb and Observe) method, and open circuit voltage method but PAO is the mostly used algorithm because it is simple and easy to implement. PAO algorithm has some drawbacks, one is low tracking speed under rapid changing weather conditions and second is oscillations of PV systems operating point around MPP. Little improvement is achieved in past papers regarding these issues. In this paper, a new method named 'Decrease and Fix' method is successfully introduced as improvement in PAO algorithm to overcome these issues of tracking speed and oscillations. Decrease and fix method is the first successful attempt with PAO algorithm for stability achievement and speeding up of tracking process in photovoltaic system. Complete standalone photovoltaic system's model with improved perturb and observe algorithm is simulated in MATLAB Simulink. (author)

  3. A Simple Short Circuit Analysis for Power Networks

    Directory of Open Access Journals (Sweden)

    Koşalay İlhan

    2016-01-01

    Full Text Available This study investigates the transient behavior of short circuits in power circuits. The circuit consists of two part; input part and load part. These two parts are connected with a circuit breaker switch. The circuit works in two modes; first mode is when the switch is open and second mode is when the switch is closed. This study analyses the circuit when the switch is closed. The analysis is done with different types of closing angle. The analysis is done by forming state equations and those equations are solved numerically by using Matlab. The analysis and conclusion is performed by observing the behaviors of the graphs.

  4. Miniaturization of Josephson logic circuits

    International Nuclear Information System (INIS)

    Ko, H.; Van Duzer, T.

    1985-01-01

    The performances of Current Injection Logic (CIL) and Resistor Coupled Josephson Logic (RCJL) have been evaluated for minimum features sizes ranging from 5 μm to 0.2 μm. The logic delay is limited to about 10 ps for both the CIL AND gate and the RCJL OR gate biased at 70% of maximum bias current. The maximum circuit count on an 6.35 x 6.35 chip is 13,000 for CIL gates and 20,000 for RCJL gates. Some suggestions are given for further improvements

  5. Maximum permissible voltage of YBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z. [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Hong, Z., E-mail: zhiyong.hong@sjtu.edu.cn [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Wang, D.; Zhou, H.; Shen, X.; Shen, C. [Qingpu Power Supply Company, State Grid Shanghai Municipal Electric Power Company, Shanghai (China)

    2014-06-15

    Highlights: • We examine three kinds of tapes’ maximum permissible voltage. • We examine the relationship between quenching duration and maximum permissible voltage. • Continuous I{sub c} degradations under repetitive quenching where tapes reaching maximum permissible voltage. • The relationship between maximum permissible voltage and resistance, temperature. - Abstract: Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (I{sub c}) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the I{sub c} degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

  6. Solid-state circuits

    CERN Document Server

    Pridham, G J

    2013-01-01

    Solid-State Circuits provides an introduction to the theory and practice underlying solid-state circuits, laying particular emphasis on field effect transistors and integrated circuits. Topics range from construction and characteristics of semiconductor devices to rectification and power supplies, low-frequency amplifiers, sine- and square-wave oscillators, and high-frequency effects and circuits. Black-box equivalent circuits of bipolar transistors, physical equivalent circuits of bipolar transistors, and equivalent circuits of field effect transistors are also covered. This volume is divided

  7. Circuit analysis for dummies

    CERN Document Server

    Santiago, John

    2013-01-01

    Circuits overloaded from electric circuit analysis? Many universities require that students pursuing a degree in electrical or computer engineering take an Electric Circuit Analysis course to determine who will ""make the cut"" and continue in the degree program. Circuit Analysis For Dummies will help these students to better understand electric circuit analysis by presenting the information in an effective and straightforward manner. Circuit Analysis For Dummies gives you clear-cut information about the topics covered in an electric circuit analysis courses to help

  8. Logic circuits from zero forcing.

    Science.gov (United States)

    Burgarth, Daniel; Giovannetti, Vittorio; Hogben, Leslie; Severini, Simone; Young, Michael

    We design logic circuits based on the notion of zero forcing on graphs; each gate of the circuits is a gadget in which zero forcing is performed. We show that such circuits can evaluate every monotone Boolean function. By using two vertices to encode each logical bit, we obtain universal computation. We also highlight a phenomenon of "back forcing" as a property of each function. Such a phenomenon occurs in a circuit when the input of gates which have been already used at a given time step is further modified by a computation actually performed at a later stage. Finally, we show that zero forcing can be also used to implement reversible computation. The model introduced here provides a potentially new tool in the analysis of Boolean functions, with particular attention to monotonicity. Moreover, in the light of applications of zero forcing in quantum mechanics, the link with Boolean functions may suggest a new directions in quantum control theory and in the study of engineered quantum spin systems. It is an open technical problem to verify whether there is a link between zero forcing and computation with contact circuits.

  9. Current limiter circuit system

    Science.gov (United States)

    Witcher, Joseph Brandon; Bredemann, Michael V.

    2017-09-05

    An apparatus comprising a steady state sensing circuit, a switching circuit, and a detection circuit. The steady state sensing circuit is connected to a first, a second and a third node. The first node is connected to a first device, the second node is connected to a second device, and the steady state sensing circuit causes a scaled current to flow at the third node. The scaled current is proportional to a voltage difference between the first and second node. The switching circuit limits an amount of current that flows between the first and second device. The detection circuit is connected to the third node and the switching circuit. The detection circuit monitors the scaled current at the third node and controls the switching circuit to limit the amount of the current that flows between the first and second device when the scaled current is greater than a desired level.

  10. Short circuit in deep brain stimulation.

    Science.gov (United States)

    Samura, Kazuhiro; Miyagi, Yasushi; Okamoto, Tsuyoshi; Hayami, Takehito; Kishimoto, Junji; Katano, Mitsuo; Kamikaseda, Kazufumi

    2012-11-01

    The authors undertook this study to investigate the incidence, cause, and clinical influence of short circuits in patients treated with deep brain stimulation (DBS). After the incidental identification of a short circuit during routine follow-up, the authors initiated a policy at their institution of routinely evaluating both therapeutic impedance and system impendence at every outpatient DBS follow-up visit, irrespective of the presence of symptoms suggesting possible system malfunction. This study represents a report of their findings after 1 year of this policy. Implanted DBS leads exhibiting short circuits were identified in 7 patients (8.9% of the patients seen for outpatient follow-up examinations during the 12-month study period). The mean duration from DBS lead implantation to the discovery of the short circuit was 64.7 months. The symptoms revealing short circuits included the wearing off of therapeutic effect, apraxia of eyelid opening, or dysarthria in 6 patients with Parkinson disease (PD), and dystonia deterioration in 1 patient with generalized dystonia. All DBS leads with short circuits had been anchored to the cranium using titanium miniplates. Altering electrode settings resulted in clinical improvement in the 2 PD cases in which patients had specific symptoms of short circuits (2.5%) but not in the other 4 cases. The patient with dystonia underwent repositioning and replacement of a lead because the previous lead was located too anteriorly, but did not experience symptom improvement. In contrast to the sudden loss of clinical efficacy of DBS caused by an open circuit, short circuits may arise due to a gradual decrease in impedance, causing the insidious development of neurological symptoms via limited or extended potential fields as well as shortened battery longevity. The incidence of short circuits in DBS may be higher than previously thought, especially in cases in which DBS leads are anchored with miniplates. The circuit impedance of DBS

  11. Protection of toroidal field coils using multiple circuits

    International Nuclear Information System (INIS)

    Thome, R.J.; Langton, W.G.; Mann, W.R.; Pillsbury, R.D.; Tarrh, J.M.

    1983-01-01

    The protection of toroidal field (TF) coils using multiple circuits is described. The discharge of a single-circuit TF system is given for purposes of definition. Two-circuit TF systems are analyzed and the results presented analytically and graphically. Induced currents, maximum discharge voltages, and discharge time constants are compared to the single-circuit system. Three-circuit TF systems are analyzed. In addition to induced currents, maximum discharge voltages, and time constants, several different discharge scenarios are included. The impacts of having discharge rates versus final maximum coil temperatures as requirements are examined. The out-of-plane forces which occur in the three-circuit system are analyzed using an approximate model. The analysis of multiplecircuit TF systems is briefly described and results for a Toroidal Fusion Core Experiment (TFCX) scale device are given based on computer analysis. The advantages and disadvantages of using multiple-circuit systems are summarized and discussed. The primary disadvantages of multiple circuits are the increased circuit complexity and potential for out-of-plane forces. These are offset by the substantial reduction in maximum discharge voltages, as well as other design options which become available when using multiple circuits

  12. Comparison of modified driver circuit and capacitor-transfer circuit in longitudinally excited N2 laser.

    Science.gov (United States)

    Uno, Kazuyuki; Akitsu, Tetsuya; Nakamura, Kenshi; Jitsuno, Takahisa

    2013-04-01

    We developed a modified driver circuit composed of a capacitance and a spark gap, called a direct-drive circuit, for a longitudinally excited gas laser. The direct-drive circuit uses a large discharge impedance caused by a long discharge length of the longitudinal excitation scheme and eliminates the buffer capacitance used in the traditional capacitor-transfer circuit. We compared the direct-drive circuit and the capacitor-transfer circuit in a longitudinally excited N2 laser (wavelength: 337 nm). Producing high output energy with the capacitor-transfer circuit requires a large storage capacitance and a discharge tube with optimum dimensions (an inner diameter of 4 mm and a length of 10 cm in this work); in contrast, the direct-drive circuit requires a high breakdown voltage, achieved with a small storage capacitance and a large discharge tube. Additionally, for the same input energy of 792 mJ, the maximum output energy of the capacitor-transfer circuit was 174.2 μJ, and that of the direct-drive circuit was 344.7 μJ.

  13. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  14. The circuit designer's companion

    CERN Document Server

    Williams, Tim

    1991-01-01

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

  15. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1972-01-01

    Electronic Devices and Circuits, Volume 3 provides a comprehensive account on electronic devices and circuits and includes introductory network theory and physics. The physics of semiconductor devices is described, along with field effect transistors, small-signal equivalent circuits of bipolar transistors, and integrated circuits. Linear and non-linear circuits as well as logic circuits are also considered. This volume is comprised of 12 chapters and begins with an analysis of the use of Laplace transforms for analysis of filter networks, followed by a discussion on the physical properties of

  16. Statistical delay estimation in digital circuits using VHDL

    Directory of Open Access Journals (Sweden)

    Milić Miljana Lj.

    2014-01-01

    Full Text Available The most important feature of modern integrated circuit is the speed. It depends on circuit's delay. For the design of high-speed digital circuits, it is necessary to evaluate delays in the earliest stages of design, thus making it easy to modify and redesign a circuit if it's too slow. This paper gives an approach for efficient delay estimation in the describing phase of the circuit design. The method can statistically estimate the minimum and maximum delay of all possible paths and signal transitions in the circuit, considering the practical implementation of circuits, and information about the parameters' tolerances. The method uses a VHDL description and is verified on ISCAS85 benchmark circuits. Matlab was used for data processing.

  17. Anomalous Capacitance Maximum of the Glassy Carbon-Ionic Liquid Interface through Dilution with Organic Solvents.

    Science.gov (United States)

    Bozym, David J; Uralcan, Betül; Limmer, David T; Pope, Michael A; Szamreta, Nicholas J; Debenedetti, Pablo G; Aksay, Ilhan A

    2015-07-02

    We use electrochemical impedance spectroscopy to measure the effect of diluting a hydrophobic room temperature ionic liquid with miscible organic solvents on the differential capacitance of the glassy carbon-electrolyte interface. We show that the minimum differential capacitance increases with dilution and reaches a maximum value at ionic liquid contents near 5-10 mol% (i.e., ∼1 M). We provide evidence that mixtures with 1,2-dichloroethane, a low-dielectric constant solvent, yield the largest gains in capacitance near the open circuit potential when compared against two traditional solvents, acetonitrile and propylene carbonate. To provide a fundamental basis for these observations, we use a coarse-grained model to relate structural variations at the double layer to the occurrence of the maximum. Our results reveal the potential for the enhancement of double-layer capacitance through dilution.

  18. Maximum Quantum Entropy Method

    OpenAIRE

    Sim, Jae-Hoon; Han, Myung Joon

    2018-01-01

    Maximum entropy method for analytic continuation is extended by introducing quantum relative entropy. This new method is formulated in terms of matrix-valued functions and therefore invariant under arbitrary unitary transformation of input matrix. As a result, the continuation of off-diagonal elements becomes straightforward. Without introducing any further ambiguity, the Bayesian probabilistic interpretation is maintained just as in the conventional maximum entropy method. The applications o...

  19. Maximum power demand cost

    International Nuclear Information System (INIS)

    Biondi, L.

    1998-01-01

    The charging for a service is a supplier's remuneration for the expenses incurred in providing it. There are currently two charges for electricity: consumption and maximum demand. While no problem arises about the former, the issue is more complicated for the latter and the analysis in this article tends to show that the annual charge for maximum demand arbitrarily discriminates among consumer groups, to the disadvantage of some [it

  20. Short communication: Use of a portable, automated, open-circuit gas quantification system and the sulfur hexafluoride tracer technique for measuring enteric methane emissions in Holstein cows fed ad libitum or restricted.

    Science.gov (United States)

    Dorich, C D; Varner, R K; Pereira, A B D; Martineau, R; Soder, K J; Brito, A F

    2015-04-01

    The objective of this study was to measure enteric CH4 emissions using a new portable automated open-circuit gas quantification system (GQS) and the sulfur hexafluoride tracer technique (SF6) in midlactation Holstein cows housed in a tiestall barn. Sixteen cows averaging 176 ± 34 d in milk, 40.7 ± 6.1 kg of milk yield, and 685 ± 49 kg of body weight were randomly assigned to 1 out of 2 treatments according to a crossover design. Treatments were (1) ad libitum (adjusted daily to yield 10% orts) and (2) restricted feed intake [set to restrict feed by 10% of baseline dry matter intake (DMI)]. Each experimental period lasted 22d, with 14 d for treatment adaptation and 8d for data and sample collection. A common diet was fed to the cows as a total mixed ration and contained 40.4% corn silage, 11.2% grass-legume haylage, and 48.4% concentrate on a dry matter basis. Spot 5-min measurements using the GQS were taken twice daily with a 12-h interval between sampling and sampling times advanced 2h daily to account for diurnal variation in CH4 emissions. Canisters for the SF6 method were sampled twice daily before milking with 4 local background gas canisters inside the barn analyzed for background gas concentrations. Enteric CH4 emissions were not affected by treatments and averaged 472 and 458 g/d (standard error of the mean = 18 g/d) for ad libitum and restricted intake treatments, respectively (data not shown). The GQS appears to be a reliable method because of the relatively low coefficients of variation (ranging from 14.1 to 22.4%) for CH4 emissions and a moderate relationship (coefficient of determination = 0.42) between CH4 emissions and DMI. The SF6 resulted in large coefficients of variation (ranging from 16.0 to 111%) for CH4 emissions and a poor relationship (coefficient of determination = 0.17) between CH4 emissions and DMI, likely because of limited barn ventilation and high background gas concentration. Research with improved barn ventilation systems or

  1. Electrical Circuits and Water Analogies

    Science.gov (United States)

    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)

  2. Electric circuits essentials

    CERN Document Server

    REA, Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Electric Circuits I includes units, notation, resistive circuits, experimental laws, transient circuits, network theorems, techniques of circuit analysis, sinusoidal analysis, polyph

  3. Piezoelectric drive circuit

    Science.gov (United States)

    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.

  4. Load testing circuit

    DEFF Research Database (Denmark)

    2009-01-01

    A load testing circuit a circuit tests the load impedance of a load connected to an amplifier. The load impedance includes a first terminal and a second terminal, the load testing circuit comprising a signal generator providing a test signal of a defined bandwidth to the first terminal of the load...

  5. Short-circuit logic

    NARCIS (Netherlands)

    Bergstra, J.A.; Ponse, A.

    2010-01-01

    Short-circuit evaluation denotes the semantics of propositional connectives in which the second argument is only evaluated if the first argument does not suffice to determine the value of the expression. In programming, short-circuit evaluation is widely used. A short-circuit logic is a variant of

  6. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2011-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

  7. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2010-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

  8. New equivalent lumped electrical circuit for piezoelectric transformers.

    Science.gov (United States)

    Gonnard, Paul; Schmitt, P M; Brissaud, Michel

    2006-04-01

    A new equivalent circuit is proposed for a contour-vibration-mode piezoelectric transformer (PT). It is shown that the usual lumped equivalent circuit derived from the conventional Mason approach is not accurate. The proposed circuit, built on experimental measurements, makes an explicit difference between the elastic energies stored respectively on the primary and secondary parts. The experimental and theoretical resonance frequencies with the secondary in open or short circuit are in good agreement as well as the output "voltage-current" characteristic and the optimum efficiency working point. This circuit can be extended to various PT configurations and appears to be a useful tool for modeling electronic devices that integrate piezoelectric transformers.

  9. Maximum likely scale estimation

    DEFF Research Database (Denmark)

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo

    2005-01-01

    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...

  10. Robust Maximum Association Estimators

    NARCIS (Netherlands)

    A. Alfons (Andreas); C. Croux (Christophe); P. Filzmoser (Peter)

    2017-01-01

    textabstractThe maximum association between two multivariate variables X and Y is defined as the maximal value that a bivariate association measure between one-dimensional projections αX and αY can attain. Taking the Pearson correlation as projection index results in the first canonical correlation

  11. Feedback in analog circuits

    CERN Document Server

    Ochoa, Agustin

    2016-01-01

    This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...

  12. Magnetic pulse compression circuits for plasma devices

    Energy Technology Data Exchange (ETDEWEB)

    Georgescu, N; Zoita, V; Presura, R [Inst. of Physics and Technology of Radiation Devices, Bucharest (Romania)

    1997-12-31

    Two magnetic pulse compression circuits (MPCC), for two different plasma devices, are presented. The first is a 20 J/pulse, 3-stage circuit designed to trigger a low pressure discharge. The circuit has 16-18 kV working voltage, and 200 nF in each stage. The saturable inductors are realized with toroidal 25 {mu}m strip-wound cores, made of a Fe-Ni alloy, with 1.5 T saturation induction. The total magnetic volume is around 290 cm{sup 3}. By using a 25 kV/1 A thyratron as a primary switch, the time compression is from 3.5 {mu}s to 450 ns, in a short-circuit load. The second magnetic pulser is a 200 J/pulse circuit, designed to drive a high average power plasma focus soft X-ray source, for X-ray microlithography as the main application. The 3-stage pulser should supply a maximum load current of 100 kA with a rise-time of 250 - 300 ns. The maximum pulse voltage applied on the plasma discharge chamber is around 20 - 25 kV. The three saturable inductors in the circuit are made of toroidal strip-wound cores with METGLAS 2605 CO amorphous alloy as the magnetic material. The total, optimized mass of the magnetic material is 34 kg. The maximum repetition rate is limited at 100 Hz by the thyratron used in the first stage of the circuit, the driver supplying to the load about 20 kW average power. (author). 1 tab., 3 figs., 3 refs.

  13. Maximum power point tracking

    International Nuclear Information System (INIS)

    Enslin, J.H.R.

    1990-01-01

    A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

  14. DMILL circuits. The hardened electronics decuples its performances

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    Thanks to the DMILL (mixed logic-linear hardening) technology under development at the CEA, MHS, a French company specialized in the fabrication of integrated circuits now produces hardened electronic circuits ten times more resistant to radiations than its competitors. Outside the initial market (several thousands of circuits for the LHC particle accelerator of Geneva), a broad choice of applications is opened to this technology: national defense, space, civil nuclear and medical engineering, and high temperature applications. Short paper. (J.S.)

  15. Circuit QED lattices: Towards quantum simulation with superconducting circuits

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Sebastian [Institute for Theoretical Physics, ETH Zurich, 8093, Zurich (Switzerland); Koch, Jens [Department of Physics and Astronomy, Northwestern University, Evanston, IL, 60208 (United States)

    2013-06-15

    The Jaynes-Cummings model describes the coupling between photons and a single two-level atom in a simplified representation of light-matter interactions. In circuit QED, this model is implemented by combining microwave resonators and superconducting qubits on a microchip with unprecedented experimental control. Arranging qubits and resonators in the form of a lattice realizes a new kind of Hubbard model, the Jaynes-Cummings-Hubbard model, in which the elementary excitations are polariton quasi-particles. Due to the genuine openness of photonic systems, circuit QED lattices offer the possibility to study the intricate interplay of collective behavior, strong correlations and non-equilibrium physics. Thus, turning circuit QED into an architecture for quantum simulation, i.e., using a well-controlled system to mimic the intricate quantum behavior of another system too daunting for a theorist to tackle head-on, is an exciting idea which has served as theorists' playground for a while and is now also starting to catch on in experiments. This review gives a summary of the most recent theoretical proposals and experimental efforts. (copyright 2013 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Electric circuits and signals

    CERN Document Server

    Sabah, Nassir H

    2007-01-01

    Circuit Variables and Elements Overview Learning Objectives Electric Current Voltage Electric Power and Energy Assigned Positive Directions Active and Passive Circuit Elements Voltage and Current Sources The Resistor The Capacitor The Inductor Concluding Remarks Summary of Main Concepts and Results Learning Outcomes Supplementary Topics on CD Problems and Exercises Basic Circuit Connections and Laws Overview Learning Objectives Circuit Terminology Kirchhoff's Laws Voltage Division and Series Connection of Resistors Current Division and Parallel Connection of Resistors D-Y Transformation Source Equivalence and Transformation Reduced-Voltage Supply Summary of Main Concepts and Results Learning Outcomes Supplementary Topics and Examples on CD Problems and Exercises Basic Analysis of Resistive Circuits Overview Learning Objectives Number of Independent Circuit Equations Node-Voltage Analysis Special Considerations in Node-Voltage Analysis Mesh-Current Analysis Special Conside...

  17. [Shunt and short circuit].

    Science.gov (United States)

    Rangel-Abundis, Alberto

    2006-01-01

    Shunt and short circuit are antonyms. In French, the term shunt has been adopted to denote the alternative pathway of blood flow. However, in French, as well as in Spanish, the word short circuit (court-circuit and cortocircuito) is synonymous with shunt, giving rise to a linguistic and scientific inconsistency. Scientific because shunt and short circuit made reference to a phenomenon that occurs in the field of the physics. Because shunt and short circuit are antonyms, it is necessary to clarify that shunt is an alternative pathway of flow from a net of high resistance to a net of low resistance, maintaining the stream. Short circuit is the interruption of the flow, because a high resistance impeaches the flood. This concept is applied to electrical and cardiovascular physiology, as well as to the metabolic pathways.

  18. Analog circuits cookbook

    CERN Document Server

    Hickman, Ian

    2013-01-01

    Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

  19. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  20. Regenerative feedback resonant circuit

    Science.gov (United States)

    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.

  1. A Compound Algorithm for Maximum Power Point Tracking Used in Laser Power Beaming

    Science.gov (United States)

    Chen, Cheng; Liu, Qiang; Gao, Shan; Teng, Yun; Cheng, Lin; Yu, Chengtao; Peng, Kai

    2018-03-01

    With the high voltage intelligent substation developing in a pretty high speed, more and more artificial intelligent techniques have been incorporated into the power devices to meet the automation needs. For the sake of the line maintenance staff’s safety, the high voltage isolating switch draws great attention among the most important power devices because of its capability of connecting and disconnecting the high voltage circuit. However, due to the very high level voltage of the high voltage isolating switch’s working environment, the power supply system of the surveillance devices could suffer from great electromagnetic interference. Laser power beaming exhibits its merits in such situation because it can provide steady power from a distance despite the day or the night. Then the energy conversion efficiency arises as a new concern. To make as much use of the laser power as possible, our work mainly focuses on extracting maximum power from the photovoltaic (PV) panel. In this paper, we proposed a neural network based algorithm which relates both the intrinsic and the extrinsic features of the PV panel to the proportion of the voltage at the maximum power point (MPP) to the open circuit voltage of the PV panel. Simulations and experiments were carried out to verify the validness of our algorithm.

  2. CMOS circuits manual

    CERN Document Server

    Marston, R M

    1995-01-01

    CMOS Circuits Manual is a user's guide for CMOS. The book emphasizes the practical aspects of CMOS and provides circuits, tables, and graphs to further relate the fundamentals with the applications. The text first discusses the basic principles and characteristics of the CMOS devices. The succeeding chapters detail the types of CMOS IC, including simple inverter, gate and logic ICs and circuits, and complex counters and decoders. The last chapter presents a miscellaneous collection of two dozen useful CMOS circuits. The book will be useful to researchers and professionals who employ CMOS circu

  3. Timergenerator circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Timer/Generator Circuits Manual is an 11-chapter text that deals mainly with waveform generator techniques and circuits. Each chapter starts with an explanation of the basic principles of its subject followed by a wide range of practical circuit designs. This work presents a total of over 300 practical circuits, diagrams, and tables.Chapter 1 outlines the basic principles and the different types of generator. Chapters 2 to 9 deal with a specific type of waveform generator, including sine, square, triangular, sawtooth, and special waveform generators pulse. These chapters also include pulse gen

  4. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1968-01-01

    Electronic Devices and Circuits, Volume 1 deals with the design and applications of electronic devices and circuits such as passive components, diodes, triodes and transistors, rectification and power supplies, amplifying circuits, electronic instruments, and oscillators. These topics are supported with introductory network theory and physics. This volume is comprised of nine chapters and begins by explaining the operation of resistive, inductive, and capacitive elements in direct and alternating current circuits. The theory for some of the expressions quoted in later chapters is presented. Th

  5. MOS integrated circuit design

    CERN Document Server

    Wolfendale, E

    2013-01-01

    MOS Integral Circuit Design aims to help in the design of integrated circuits, especially large-scale ones, using MOS Technology through teaching of techniques, practical applications, and examples. The book covers topics such as design equation and process parameters; MOS static and dynamic circuits; logic design techniques, system partitioning, and layout techniques. Also featured are computer aids such as logic simulation and mask layout, as well as examples on simple MOS design. The text is recommended for electrical engineers who would like to know how to use MOS for integral circuit desi

  6. Circuits and filters handbook

    CERN Document Server

    Chen, Wai-Kai

    2003-01-01

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

  7. Security electronics circuits manual

    CERN Document Server

    MARSTON, R M

    1998-01-01

    Security Electronics Circuits Manual is an invaluable guide for engineers and technicians in the security industry. It will also prove to be a useful guide for students and experimenters, as well as providing experienced amateurs and DIY enthusiasts with numerous ideas to protect their homes, businesses and properties.As with all Ray Marston's Circuits Manuals, the style is easy-to-read and non-mathematical, with the emphasis firmly on practical applications, circuits and design ideas. The ICs and other devices used in the practical circuits are modestly priced and readily available ty

  8. Maximum entropy methods

    International Nuclear Information System (INIS)

    Ponman, T.J.

    1984-01-01

    For some years now two different expressions have been in use for maximum entropy image restoration and there has been some controversy over which one is appropriate for a given problem. Here two further entropies are presented and it is argued that there is no single correct algorithm. The properties of the four different methods are compared using simple 1D simulations with a view to showing how they can be used together to gain as much information as possible about the original object. (orig.)

  9. RC Circuits: Some Computer-Interfaced Experiments.

    Science.gov (United States)

    Jolly, Pratibha; Verma, Mallika

    1994-01-01

    Describes a simple computer-interface experiment for recording the response of an RC network to an arbitrary input excitation. The setup is used to pose a variety of open-ended investigations in network modeling by varying the initial conditions, input signal waveform, and the circuit topology. (DDR)

  10. Maximum power point tracker for portable photovoltaic systems with resistive-like load

    Energy Technology Data Exchange (ETDEWEB)

    De Cesare, G.; Caputo, D.; Nascetti, A. [Department of Electronic Engineering, University of Rome La Sapienza via Eudossiana, 18 00184 Rome (Italy)

    2006-08-15

    In this work we report on the design and realization of a maximum power point tracking (MPPT) circuit suitable for low power, portable applications with resistive load. The design rules included cost, size and power efficiency considerations. A novel scheme for the implementation of the control loop of the MPPT circuit is proposed, combining good performance with compact design. The operation and performances were simulated at circuit schematic level with simulation program with integrated circuit emphasis (SPICE). The improved operation of a PV system using our MPPT circuit was demonstrated using a purely resistive load. (author)

  11. The last glacial maximum

    Science.gov (United States)

    Clark, P.U.; Dyke, A.S.; Shakun, J.D.; Carlson, A.E.; Clark, J.; Wohlfarth, B.; Mitrovica, J.X.; Hostetler, S.W.; McCabe, A.M.

    2009-01-01

    We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation, tropical Pacific sea surface temperatures, and atmospheric CO2. Nearly all ice sheets were at their LGM positions from 26.5 ka to 19 to 20 ka, corresponding to minima in these forcings. The onset of Northern Hemisphere deglaciation 19 to 20 ka was induced by an increase in northern summer insolation, providing the source for an abrupt rise in sea level. The onset of deglaciation of the West Antarctic Ice Sheet occurred between 14 and 15 ka, consistent with evidence that this was the primary source for an abrupt rise in sea level ???14.5 ka.

  12. Automatic ranging circuit for a digital panel meter

    International Nuclear Information System (INIS)

    Mueller, T.R.; Ross, H.H.

    1976-01-01

    This invention relates to a range changing circuit that operates in conjunction with a digital panel meter of fixed sensitivity. The circuit decodes the output of the panel meter and uses that information to change the gain of an input amplifier to the panel meter in order to ensure that the maximum number of significant figures is always displayed in the meter. The circuit monitors five conditions in the meter and responds to any of four combinations of these conditions by means of logic elements to carry out the function of the circuit. The system was designed for readout of a fluorescence analyzer for uranium analysis

  13. High performance protection circuit for power electronics applications

    Energy Technology Data Exchange (ETDEWEB)

    Tudoran, Cristian D., E-mail: cristian.tudoran@itim-cj.ro; Dădârlat, Dorin N.; Toşa, Nicoleta; Mişan, Ioan [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, PO 5 Box 700, 400293 Cluj-Napoca (Romania)

    2015-12-23

    In this paper we present a high performance protection circuit designed for the power electronics applications where the load currents can increase rapidly and exceed the maximum allowed values, like in the case of high frequency induction heating inverters or high frequency plasma generators. The protection circuit is based on a microcontroller and can be adapted for use on single-phase or three-phase power systems. Its versatility comes from the fact that the circuit can communicate with the protected system, having the role of a “sensor” or it can interrupt the power supply for protection, in this case functioning as an external, independent protection circuit.

  14. Maximum Entropy Fundamentals

    Directory of Open Access Journals (Sweden)

    F. Topsøe

    2001-09-01

    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  15. Probable maximum flood control

    International Nuclear Information System (INIS)

    DeGabriele, C.E.; Wu, C.L.

    1991-11-01

    This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility

  16. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1988-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. We review the need for such methods in data analysis and show, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. We conclude with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  17. Solar maximum observatory

    International Nuclear Information System (INIS)

    Rust, D.M.

    1984-01-01

    The successful retrieval and repair of the Solar Maximum Mission (SMM) satellite by Shuttle astronauts in April 1984 permitted continuance of solar flare observations that began in 1980. The SMM carries a soft X ray polychromator, gamma ray, UV and hard X ray imaging spectrometers, a coronagraph/polarimeter and particle counters. The data gathered thus far indicated that electrical potentials of 25 MeV develop in flares within 2 sec of onset. X ray data show that flares are composed of compressed magnetic loops that have come too close together. Other data have been taken on mass ejection, impacts of electron beams and conduction fronts with the chromosphere and changes in the solar radiant flux due to sunspots. 13 references

  18. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1989-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. The author reviews the need for such methods in data analysis and shows, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. He concludes with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  19. Functional Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg

    2005-01-01

    MAF outperforms the functional PCA in concentrating the interesting' spectra/shape variation in one end of the eigenvalue spectrum and allows for easier interpretation of effects. Conclusions. Functional MAF analysis is a useful methods for extracting low dimensional models of temporally or spatially......Purpose. We aim at data where samples of an underlying function are observed in a spatial or temporal layout. Examples of underlying functions are reflectance spectra and biological shapes. We apply functional models based on smoothing splines and generalize the functional PCA in......\\verb+~+\\$\\backslash\\$cite{ramsay97} to functional maximum autocorrelation factors (MAF)\\verb+~+\\$\\backslash\\$cite{switzer85,larsen2001d}. We apply the method to biological shapes as well as reflectance spectra. {\\$\\backslash\\$bf Methods}. MAF seeks linear combination of the original variables that maximize autocorrelation between...

  20. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yunji; Jing, Bing-Yi; Gao, Xin

    2015-01-01

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  1. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan

    2015-02-12

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  2. Circuits on Cylinders

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Miltersen, Peter Bro; Vinay, V

    2006-01-01

    We consider the computational power of constant width polynomial size cylindrical circuits and nondeterministic branching programs. We show that every function computed by a Pi2 o MOD o AC0 circuit can also be computed by a constant width polynomial size cylindrical nondeterministic branching pro...

  3. Integrated reconfigurable high-voltage transmitting circuit for CMUTs

    DEFF Research Database (Denmark)

    Llimos Muntal, Pere; Larsen, Dennis Øland; Jørgensen, Ivan Harald Holger

    2015-01-01

    In this paper a high-voltage transmitting circuit aimed for capacitive micromachined ultrasonic transducers (CMUTs) used in scanners for medical applications is designed and implemented in a 0.35 μm high-voltage CMOS process. The transmitting circuit is reconfigurable externally making it able...... to drive a wide variety of CMUTs. The transmitting circuit can generate several pulse shapes with voltages up to 100 V, maximum pulse range of 50 V, frequencies up to 5 MHz and different driving slew rates. Measurements are performed on the circuit in order to assess its functionality and power consumption...... performance. The design occupies an on-chip area of 0.938 mm2 and the power consumption of a 128-element transmitting circuit array that would be used in an portable ultrasound scanner is found to be a maximum of 181 mW....

  4. SIMULATION OF NEW SIMPLE FUZZY LOGIC MAXIMUM POWER ...

    African Journals Online (AJOL)

    2010-06-30

    Jun 30, 2010 ... Basic structure photovoltaic system Solar array mathematic ... The equivalent circuit model of a solar cell consists of a current generator and a diode .... control of boost converter (tracker) such that maximum power is achieved at the output of the solar panel. Fig.11. The membership function of input. Fig.12.

  5. CMOS analog circuit design

    CERN Document Server

    Allen, Phillip E

    1987-01-01

    This text presents the principles and techniques for designing analog circuits to be implemented in a CMOS technology. The level is appropriate for seniors and graduate students familiar with basic electronics, including biasing, modeling, circuit analysis, and some familiarity with frequency response. Students learn the methodology of analog integrated circuit design through a hierarchically-oriented approach to the subject that provides thorough background and practical guidance for designing CMOS analog circuits, including modeling, simulation, and testing. The authors' vast industrial experience and knowledge is reflected in the circuits, techniques, and principles presented. They even identify the many common pitfalls that lie in the path of the beginning designer--expert advice from veteran designers. The text mixes the academic and practical viewpoints in a treatment that is neither superficial nor overly detailed, providing the perfect balance.

  6. Hydraulic actuator for an electric circuit breaker

    Science.gov (United States)

    Imam, Imdad [Colonie, NY

    1983-01-01

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

  7. Multi-qubit circuit quantum electrodynamics

    International Nuclear Information System (INIS)

    Viehmann, Oliver

    2013-01-01

    Circuit QED systems are macroscopic, man-made quantum systems in which superconducting artificial atoms, also called Josephson qubits, interact with a quantized electromagnetic field. These systems have been devised to mimic the physics of elementary quantum optical systems with real atoms in a scalable and more flexible framework. This opens up a variety of possible applications of circuit QED systems. For instance, they provide a promising platform for processing quantum information. Recent years have seen rapid experimental progress on these systems, and experiments with multi-component circuit QED architectures are currently starting to come within reach. In this thesis, circuit QED systems with multiple Josephson qubits are studied theoretically. We focus on simple and experimentally realistic extensions of the currently operated circuit QED setups and pursue investigations in two main directions. First, we consider the equilibrium behavior of circuit QED systems containing a large number of mutually noninteracting Josephson charge qubits. The currently accepted standard description of circuit QED predicts the possibility of superradiant phase transitions in such systems. However, a full microscopic treatment shows that a no-go theorem for superradiant phase transitions known from atomic physics applies to circuit QED systems as well. This reveals previously unknown limitations of the applicability of the standard theory of circuit QED to multi-qubit systems. Second, we explore the potential of circuit QED for quantum simulations of interacting quantum many-body systems. We propose and analyze a circuit QED architecture that implements the quantum Ising chain in a time-dependent transverse magnetic field. Our setup can be used to study quench dynamics, the propagation of localized excitations, and other non-equilibrium features in this paradigmatic model in the theory of non-equilibrium thermodynamics and quantumcritical phenomena. The setup is based on a

  8. Multi-qubit circuit quantum electrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Viehmann, Oliver

    2013-09-03

    Circuit QED systems are macroscopic, man-made quantum systems in which superconducting artificial atoms, also called Josephson qubits, interact with a quantized electromagnetic field. These systems have been devised to mimic the physics of elementary quantum optical systems with real atoms in a scalable and more flexible framework. This opens up a variety of possible applications of circuit QED systems. For instance, they provide a promising platform for processing quantum information. Recent years have seen rapid experimental progress on these systems, and experiments with multi-component circuit QED architectures are currently starting to come within reach. In this thesis, circuit QED systems with multiple Josephson qubits are studied theoretically. We focus on simple and experimentally realistic extensions of the currently operated circuit QED setups and pursue investigations in two main directions. First, we consider the equilibrium behavior of circuit QED systems containing a large number of mutually noninteracting Josephson charge qubits. The currently accepted standard description of circuit QED predicts the possibility of superradiant phase transitions in such systems. However, a full microscopic treatment shows that a no-go theorem for superradiant phase transitions known from atomic physics applies to circuit QED systems as well. This reveals previously unknown limitations of the applicability of the standard theory of circuit QED to multi-qubit systems. Second, we explore the potential of circuit QED for quantum simulations of interacting quantum many-body systems. We propose and analyze a circuit QED architecture that implements the quantum Ising chain in a time-dependent transverse magnetic field. Our setup can be used to study quench dynamics, the propagation of localized excitations, and other non-equilibrium features in this paradigmatic model in the theory of non-equilibrium thermodynamics and quantumcritical phenomena. The setup is based on a

  9. Solar maximum mission

    International Nuclear Information System (INIS)

    Ryan, J.

    1981-01-01

    By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

  10. Approximate circuits for increased reliability

    Science.gov (United States)

    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.

  11. Fast-responding short circuit protection system with self-reset for use in circuit supplied by DC power

    Science.gov (United States)

    Burns, Bradley M. (Inventor); Blalock, Norman N. (Inventor)

    2011-01-01

    A short circuit protection system includes an inductor, a switch, a voltage sensing circuit, and a controller. The switch and inductor are electrically coupled to be in series with one another. A voltage sensing circuit is coupled across the switch and the inductor. A controller, coupled to the voltage sensing circuit and the switch, opens the switch when a voltage at the output terminal of the inductor transitions from above a threshold voltage to below the threshold voltage. The controller closes the switch when the voltage at the output terminal of the inductor transitions from below the threshold voltage to above the threshold voltage.

  12. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

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

  13. Modern TTL circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Modern TTL Circuits Manual provides an introduction to the basic principles of Transistor-Transistor Logic (TTL). This book outlines the major features of the 74 series of integrated circuits (ICs) and introduces the various sub-groups of the TTL family.Organized into seven chapters, this book begins with an overview of the basics of digital ICs. This text then examines the symbology and mathematics of digital logic. Other chapters consider a variety of topics, including waveform generator circuitry, clocked flip-flop and counter circuits, special counter/dividers, registers, data latches, com

  14. Circuit analysis with Multisim

    CERN Document Server

    Baez-Lopez, David

    2011-01-01

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

  15. Optoelectronics circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

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

  16. 'Speedy' superconducting circuits

    International Nuclear Information System (INIS)

    Holst, T.

    1994-01-01

    The most promising concept for realizing ultra-fast superconducting digital circuits is the Rapid Single Flux Quantum (RSFQ) logic. The basic physical principle behind RSFQ logic, which include the storage and transfer of individual magnetic flux quanta in Superconducting Quantum Interference Devices (SQUIDs), is explained. A Set-Reset flip-flop is used as an example of the implementation of an RSFQ based circuit. Finally, the outlook for high-temperature superconducting materials in connection with RSFQ circuits is discussed in some details. (au)

  17. Analogue circuits simulation

    Energy Technology Data Exchange (ETDEWEB)

    Mendo, C

    1988-09-01

    Most analogue simulators have evolved from SPICE. The history and description of SPICE-like simulators are given. From a mathematical formulation of the electronic circuit the following analysis are possible: DC, AC, transient, noise, distortion, Worst Case and Statistical.

  18. Printed circuit for ATLAS

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    A printed circuit board made by scientists in the ATLAS collaboration for the transition radiaton tracker (TRT). This will read data produced when a high energy particle crosses the boundary between two materials with different electrical properties.

  19. Magnonic logic circuits

    International Nuclear Information System (INIS)

    Khitun, Alexander; Bao Mingqiang; Wang, Kang L

    2010-01-01

    We describe and analyse possible approaches to magnonic logic circuits and basic elements required for circuit construction. A distinctive feature of the magnonic circuitry is that information is transmitted by spin waves propagating in the magnetic waveguides without the use of electric current. The latter makes it possible to exploit spin wave phenomena for more efficient data transfer and enhanced logic functionality. We describe possible schemes for general computing and special task data processing. The functional throughput of the magnonic logic gates is estimated and compared with the conventional transistor-based approach. Magnonic logic circuits allow scaling down to the deep submicrometre range and THz frequency operation. The scaling is in favour of the magnonic circuits offering a significant functional advantage over the traditional approach. The disadvantages and problems of the spin wave devices are also discussed.

  20. Circuit breaker operation and potential failure modes during an earthquake

    International Nuclear Information System (INIS)

    Lambert, H.E.; Budnitz, R.J.

    1987-01-01

    This study addresses the effect of a strong-motion earthquake on circuit breaker operation. It focuses on the loss of offsite power (LOSP) transient caused by a strong-motion earthquake at the Zion Nuclear Power Plant. This paper also describes the operator action necessary to prevent core melt if the above circuit breaker failure modes occur simultaneously on three 4.16 KV buses. Numerous circuit breakers important to plant safety, such as circuit breakers to diesel generators and engineered safety systems (ESS), must open and/or close during this transient while strong motion is occurring. Potential seismically-induced circuit-breaker failures modes were uncovered while the study was conducted. These failure modes include: circuit breaker fails to close; circuit breaker trips inadvertently; circuit breaker fails to reclose after trip. The causes of these failure modes include: Relay chatter causes the circuit breaker to trip; Relay chatter causes anti-pumping relays to seal-in which prevents automatic closure of circuit breakers; Load sequencer failures. The incorporation of these failure modes as well as other instrumentation and control failures into a limited scope seismic probabilistic risk assessment is also discussed in this paper

  1. Maximum mouth opening of ethnic Chinese in Taiwan

    Directory of Open Access Journals (Sweden)

    Kuang-Ta Yao

    2009-03-01

    Conclusion: Within the limits of this study, we concluded that both sex and age have significant influences on the MMO value of ethnic Chinese in Taiwan, and age is a significant predictor of MMO measurements.

  2. Project Circuits in a Basic Electric Circuits Course

    Science.gov (United States)

    Becker, James P.; Plumb, Carolyn; Revia, Richard A.

    2014-01-01

    The use of project circuits (a photoplethysmograph circuit and a simple audio amplifier), introduced in a sophomore-level electric circuits course utilizing active learning and inquiry-based methods, is described. The development of the project circuits was initiated to promote enhanced engagement and deeper understanding of course content among…

  3. Application of Memristors in Microwave Passive Circuits

    Directory of Open Access Journals (Sweden)

    M.Potrebic

    2015-06-01

    Full Text Available The recent implementation of the fourth fundamental electric circuit element, the memristor, opened new vistas in many fields of engineering applications. In this paper, we explore several RF/microwave passive circuits that might benefit from the memristor salient characteristics. We consider a power divider, coupled resonator bandpass filters, and a low-reflection quasi-Gaussian lowpass filter with lossy elements. We utilize memristors as configurable linear resistors and we propose memristor-based bandpass filters that feature suppression of parasitic frequency pass bands and widening of the desired rejection band. The simulations are performed in the time domain, using LTspice, and the RF/microwave circuits under consideration are modeled by ideal elements available in LTspice.

  4. Financial-real side interactions in the monetary circuit: loving or dangerous hugs?

    OpenAIRE

    Botta, Alberto; Caverzasi, Eugenio; Tori, Daniele

    2015-01-01

    Monetary circuit theory is one of the most known attempts to formally describe the functioning of a monetary production economy as centered around the concept of flux-reflux of money. Endogenous money creation by commercial banks allows the circuit to open and firms to implement production processes. Financial markets ‘passively’ close the circuit by intermediating savings via bond and equity issuance. Despite its natural focus on financial-real side links, the monetary circuit literature has...

  5. A counting-card circuit based on PCI bus

    International Nuclear Information System (INIS)

    Shi Jing; Li Yong; Chinese Academy of Sciences, Lanzhou; Su Hong; Dong Chengfu; Li Xiaogang; Ma Xiaoli

    2004-01-01

    A counting-card circuit based on PCI bus that we developed recently used for advanced personal computer will be introduced in this paper briefly. The maximum count capacity of this counting-card is 10 9 -1, ranging from 0 to 999 999 999, the maximum counting time range, 1 x 10 6 s, can be set in 1 cycle, the maximum counting rate is 20 MHz for positive input. (authors)

  6. Effect of external circuit on heat transfer in MHD Couette flow

    International Nuclear Information System (INIS)

    Soundalgekar, V.M.

    1982-01-01

    An exact solution of energy equation in fully-developed MHD Coutte flow has been derived. Temperature profiles are shown in open- and short-circuit cases. It has been observed that in short circuit case, temperature and Nusselt number (Nu) increase with increasing M, whereas in open-circuit case, with increasing M, the temperature decreases. Also in open-circuit case, Nu increases with increasing M when M is small, but at large values of M, Nu decreases with increasing M. (author)

  7. Low latency asynchronous interface circuits

    Science.gov (United States)

    Sadowski, Greg

    2017-06-20

    In one form, a logic circuit includes an asynchronous logic circuit, a synchronous logic circuit, and an interface circuit coupled between the asynchronous logic circuit and the synchronous logic circuit. The asynchronous logic circuit has a plurality of asynchronous outputs for providing a corresponding plurality of asynchronous signals. The synchronous logic circuit has a plurality of synchronous inputs corresponding to the plurality of asynchronous outputs, a stretch input for receiving a stretch signal, and a clock output for providing a clock signal. The synchronous logic circuit provides the clock signal as a periodic signal but prolongs a predetermined state of the clock signal while the stretch signal is active. The asynchronous interface detects whether metastability could occur when latching any of the plurality of the asynchronous outputs of the asynchronous logic circuit using said clock signal, and activates the stretch signal while the metastability could occur.

  8. Thermally-induced voltage alteration for integrated circuit analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cole, E.I. Jr.

    2000-06-20

    A thermally-induced voltage alteration (TIVA) apparatus and method are disclosed for analyzing an integrated circuit (IC) either from a device side of the IC or through the IC substrate to locate any open-circuit or short-circuit defects therein. The TIVA apparatus uses constant-current biasing of the IC while scanning a focused laser beam over electrical conductors (i.e. a patterned metallization) in the IC to produce localized heating of the conductors. This localized heating produces a thermoelectric potential due to the Seebeck effect in any conductors with open-circuit defects and a resistance change in any conductors with short-circuit defects, both of which alter the power demand by the IC and thereby change the voltage of a source or power supply providing the constant-current biasing. By measuring the change in the supply voltage and the position of the focused and scanned laser beam over time, any open-circuit or short-circuit defects in the IC can be located and imaged. The TIVA apparatus can be formed in part from a scanning optical microscope, and has applications for qualification testing or failure analysis of ICs.

  9. Analysis of emergency operating procedures effectiveness for core damage prevention using computer code RELAP for nuclear power plants with VVER-1000/B-320 in reference to primary to secondary circuit leak with external power loss and BRU-A stuck open failure

    International Nuclear Information System (INIS)

    Arkhangelski, L.; Sheveliov, D. V.

    1999-01-01

    This report presents analysis of development emergency operating procedures effectiveness for possible accident on nuclear power plant with WWER-1000 reactor type. Accident initiating event is the primary to secondary circuit leak caused by steam generator primary cover lift-up. In according to conservative assumptions the following additional failures were considered: dump valve BRU-A stuck open failure; loss of external power. The results of this work are represented as a comparative analysis of two possible ways of accident evolution: according to functioning automatic safety systems responses; according to accident management based on development emergency operating procedures with operator intervention. Developed emergency operating procedures assure the following significant goals to mitigate accident sequences: optimal use of ECCS water inventory; severe core damage prevention; mitigation of environment radioactive contamination. (authors)

  10. Analysis of electronic circuits using digital computers

    International Nuclear Information System (INIS)

    Tapu, C.

    1968-01-01

    Various programmes have been proposed for studying electronic circuits with the help of computers. It is shown here how it possible to use the programme ECAP, developed by I.B.M., for studying the behaviour of an operational amplifier from different point of view: direct current, alternating current and transient state analysis, optimisation of the gain in open loop, study of the reliability. (author) [fr

  11. Geometrical prediction of maximum power point for photovoltaics

    International Nuclear Information System (INIS)

    Kumar, Gaurav; Panchal, Ashish K.

    2014-01-01

    Highlights: • Direct MPP finding by parallelogram constructed from geometry of I–V curve of cell. • Exact values of V and P at MPP obtained by Lagrangian interpolation exploration. • Extensive use of Lagrangian interpolation for implementation of proposed method. • Method programming on C platform with minimum computational burden. - Abstract: It is important to drive solar photovoltaic (PV) system to its utmost capacity using maximum power point (MPP) tracking algorithms. This paper presents a direct MPP prediction method for a PV system considering the geometry of the I–V characteristic of a solar cell and a module. In the first step, known as parallelogram exploration (PGE), the MPP is determined from a parallelogram constructed using the open circuit (OC) and the short circuit (SC) points of the I–V characteristic and Lagrangian interpolation. In the second step, accurate values of voltage and power at the MPP, defined as V mp and P mp respectively, are decided by the Lagrangian interpolation formula, known as the Lagrangian interpolation exploration (LIE). Specifically, this method works with a few (V, I) data points instead most of the MPP algorithms work with (P, V) data points. The performance of the method is examined by several PV technologies including silicon, copper indium gallium selenide (CIGS), copper zinc tin sulphide selenide (CZTSSe), organic, dye sensitized solar cell (DSSC) and organic tandem cells’ data previously reported in literatures. The effectiveness of the method is tested experimentally for a few silicon cells’ I–V characteristics considering variation in the light intensity and the temperature. At last, the method is also employed for a 10 W silicon module tested in the field. To testify the preciseness of the method, an absolute value of the derivative of power (P) with respect to voltage (V) defined as (dP/dV) is evaluated and plotted against V. The method estimates the MPP parameters with high accuracy for any

  12. Junction and circuit fabrication

    International Nuclear Information System (INIS)

    Jackel, L.D.

    1980-01-01

    Great strides have been made in Josephson junction fabrication in the four years since the first IC SQUID meeting. Advances in lithography have allowed the production of devices with planar dimensions as small as a few hundred angstroms. Improved technology has provided ultra-high sensitivity SQUIDS, high-efficiency low-noise mixers, and complex integrated circuits. This review highlights some of the new fabrication procedures. The review consists of three parts. Part 1 is a short summary of the requirements on junctions for various applications. Part 2 reviews intergrated circuit fabrication, including tunnel junction logic circuits made at IBM and Bell Labs, and microbridge radiation sources made at SUNY at Stony Brook. Part 3 describes new junction fabrication techniques, the major emphasis of this review. This part includes a discussion of small oxide-barrier tunnel junctions, semiconductor barrier junctions, and microbridge junctions. Part 3 concludes by considering very fine lithography and limitations to miniaturization. (orig.)

  13. Small circuits for cryptography.

    Energy Technology Data Exchange (ETDEWEB)

    Torgerson, Mark Dolan; Draelos, Timothy John; Schroeppel, Richard Crabtree; Miller, Russell D.; Anderson, William Erik

    2005-10-01

    This report examines a number of hardware circuit design issues associated with implementing certain functions in FPGA and ASIC technologies. Here we show circuit designs for AES and SHA-1 that have an extremely small hardware footprint, yet show reasonably good performance characteristics as compared to the state of the art designs found in the literature. Our AES performance numbers are fueled by an optimized composite field S-box design for the Stratix chipset. Our SHA-1 designs use register packing and feedback functionalities of the Stratix LE, which reduce the logic element usage by as much as 72% as compared to other SHA-1 designs.

  14. Silicon integrated circuit process

    International Nuclear Information System (INIS)

    Lee, Jong Duck

    1985-12-01

    This book introduces the process of silicon integrated circuit. It is composed of seven parts, which are oxidation process, diffusion process, ion implantation process such as ion implantation equipment, damage, annealing and influence on manufacture of integrated circuit and device, chemical vapor deposition process like silicon Epitaxy LPCVD and PECVD, photolithography process, including a sensitizer, spin, harden bake, reflection of light and problems related process, infrared light bake, wet-etch, dry etch, special etch and problems of etching, metal process like metal process like metal-silicon connection, aluminum process, credibility of aluminum and test process.

  15. Primer printed circuit boards

    CERN Document Server

    Argyle, Andrew

    2009-01-01

    Step-by-step instructions for making your own PCBs at home. Making your own printed circuit board (PCB) might seem a daunting task, but once you master the steps, it's easy to attain professional-looking results. Printed circuit boards, which connect chips and other components, are what make almost all modern electronic devices possible. PCBs are made from sheets of fiberglass clad with copper, usually in multiplelayers. Cut a computer motherboard in two, for instance, and you'll often see five or more differently patterned layers. Making boards at home is relatively easy

  16. Silicon integrated circuit process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Duck

    1985-12-15

    This book introduces the process of silicon integrated circuit. It is composed of seven parts, which are oxidation process, diffusion process, ion implantation process such as ion implantation equipment, damage, annealing and influence on manufacture of integrated circuit and device, chemical vapor deposition process like silicon Epitaxy LPCVD and PECVD, photolithography process, including a sensitizer, spin, harden bake, reflection of light and problems related process, infrared light bake, wet-etch, dry etch, special etch and problems of etching, metal process like metal process like metal-silicon connection, aluminum process, credibility of aluminum and test process.

  17. Circuit design for reliability

    CERN Document Server

    Cao, Yu; Wirth, Gilson

    2015-01-01

    This book presents physical understanding, modeling and simulation, on-chip characterization, layout solutions, and design techniques that are effective to enhance the reliability of various circuit units.  The authors provide readers with techniques for state of the art and future technologies, ranging from technology modeling, fault detection and analysis, circuit hardening, and reliability management. Provides comprehensive review on various reliability mechanisms at sub-45nm nodes; Describes practical modeling and characterization techniques for reliability; Includes thorough presentation of robust design techniques for major VLSI design units; Promotes physical understanding with first-principle simulations.

  18. Electronic circuits fundamentals & applications

    CERN Document Server

    Tooley, Mike

    2015-01-01

    Electronics explained in one volume, using both theoretical and practical applications.New chapter on Raspberry PiCompanion website contains free electronic tools to aid learning for students and a question bank for lecturersPractical investigations and questions within each chapter help reinforce learning Mike Tooley provides all the information required to get to grips with the fundamentals of electronics, detailing the underpinning knowledge necessary to appreciate the operation of a wide range of electronic circuits, including amplifiers, logic circuits, power supplies and oscillators. The

  19. Displacement damage analysis and modified electrical equivalent circuit for electron and photon-irradiated silicon solar cells

    Science.gov (United States)

    Arjhangmehr, Afshin; Feghhi, Seyed Amir Hossein

    2014-10-01

    Solar modules and arrays are the conventional energy resources of space satellites. Outside the earth's atmosphere, solar panels experience abnormal radiation environments and because of incident particles, photovoltaic (PV) parameters degrade. This article tries to analyze the electrical performance of electron and photon-irradiated mono-crystalline silicon (mono-Si) solar cells. PV cells are irradiated by mono-energetic electrons and poly-energetic photons and immediately characterized after the irradiation. The mean degradation of the maximum power (Pmax) of silicon solar cells is presented and correlated using the displacement damage dose (Dd) methodology. This method simplifies evaluation of cell performance in space radiation environments and produces a single characteristic curve for Pmax degradation. Furthermore, complete analysis of the results revealed that the open-circuit voltage (Voc) and the filling factor of mono-Si cells did not significantly change during the irradiation and were independent of the radiation type and fluence. Moreover, a new technique is developed that adapts the irradiation-induced effects in a single-cell equivalent electrical circuit and adjusts its elements. The "modified circuit" is capable of modeling the "radiation damage" in the electrical behavior of mono-Si solar cells and simplifies the designing of the compensation circuits.

  20. Application of Circuit Model for Photovoltaic Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Natarajan Pandiarajan

    2012-01-01

    Full Text Available Circuit model of photovoltaic (PV module is presented in this paper that can be used as a common platform by material scientists and power electronic circuit designers to develop better PV power plant. Detailed modeling procedure for the circuit model with numerical dimensions is presented using power system blockset of MATLAB/Simulink. The developed model is integrated with DC-DC boost converter with closed-loop control of maximum power point tracking (MPPT algorithm. Simulation results are validated with the experimental setup.

  1. Credal Networks under Maximum Entropy

    OpenAIRE

    Lukasiewicz, Thomas

    2013-01-01

    We apply the principle of maximum entropy to select a unique joint probability distribution from the set of all joint probability distributions specified by a credal network. In detail, we start by showing that the unique joint distribution of a Bayesian tree coincides with the maximum entropy model of its conditional distributions. This result, however, does not hold anymore for general Bayesian networks. We thus present a new kind of maximum entropy models, which are computed sequentially. ...

  2. ESD analog circuits and design

    CERN Document Server

    Voldman, Steven H

    2014-01-01

    A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

  3. Unstable oscillators based hyperchaotic circuit

    DEFF Research Database (Denmark)

    Murali, K.; Tamasevicius, A.; G. Mykolaitis, A.

    1999-01-01

    A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations in the circ...... in the circuit. The performance of the circuit is investigated by means of numerical integration of appropriate differential equations, PSPICE simulations, and hardware experiment.......A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations...

  4. The test of VLSI circuits

    Science.gov (United States)

    Baviere, Ph.

    Tests which have proven effective for evaluating VLSI circuits for space applications are described. It is recommended that circuits be examined after each manfacturing step to gain fast feedback on inadequacies in the production system. Data from failure modes which occur during operational lifetimes of circuits also permit redefinition of the manufacturing and quality control process to eliminate the defects identified. Other tests include determination of the operational envelope of the circuits, examination of the circuit response to controlled inputs, and the performance and functional speeds of ROM and RAM memories. Finally, it is desirable that all new circuits be designed with testing in mind.

  5. Electronic Circuit Analysis Language (ECAL)

    Science.gov (United States)

    Chenghang, C.

    1983-03-01

    The computer aided design technique is an important development in computer applications and it is an important component of computer science. The special language for electronic circuit analysis is the foundation of computer aided design or computer aided circuit analysis (abbreviated as CACD and CACA) of simulated circuits. Electronic circuit analysis language (ECAL) is a comparatively simple and easy to use circuit analysis special language which uses the FORTRAN language to carry out the explanatory executions. It is capable of conducting dc analysis, ac analysis, and transient analysis of a circuit. Futhermore, the results of the dc analysis can be used directly as the initial conditions for the ac and transient analyses.

  6. An integrated circuit switch

    Science.gov (United States)

    Bonin, E. L.

    1969-01-01

    Multi-chip integrated circuit switch consists of a GaAs photon-emitting diode in close proximity with S1 phototransistor. A high current gain is obtained when the transistor has a high forward common-emitter current gain.

  7. Automatic sweep circuit

    International Nuclear Information System (INIS)

    Keefe, D.J.

    1980-01-01

    An automatically sweeping circuit for searching for an evoked response in an output signal in time with respect to a trigger input is described. Digital counters are used to activate a detector at precise intervals, and monitoring is repeated for statistical accuracy. If the response is not found then a different time window is examined until the signal is found

  8. Automatic sweep circuit

    Science.gov (United States)

    Keefe, Donald J.

    1980-01-01

    An automatically sweeping circuit for searching for an evoked response in an output signal in time with respect to a trigger input. Digital counters are used to activate a detector at precise intervals, and monitoring is repeated for statistical accuracy. If the response is not found then a different time window is examined until the signal is found.

  9. "Printed-circuit" rectenna

    Science.gov (United States)

    Dickinson, R. M.

    1977-01-01

    Rectifying antenna is less bulky structure for absorbing transmitted microwave power and converting it into electrical current. Printed-circuit approach, using microstrip technology and circularly polarized antenna, makes polarization orientation unimportant and allows much smaller arrays for given performance. Innovation is particularly useful with proposed electric vehicles powered by beam microwaves.

  10. Het onzichtbare circuit

    NARCIS (Netherlands)

    Nauta, Bram

    2013-01-01

    De chip, of geïntegreerde schakeling, heeft in een razend tempo ons leven ingrijpend veranderd. Het lijkt zo vanzelfsprekend dat er weer een nieuwe generatie smartphones, tablets of computers is. Maar dat is het niet. Prof.dr.ir. Bram Nauta, hoogleraar Integrated Circuit Design, laat in zijn rede

  11. Voltage regulating circuit

    NARCIS (Netherlands)

    2005-01-01

    A voltage regulating circuit comprising a rectifier (2) for receiving an AC voltage (Vmains) and for generating a rectified AC voltage (vrec), and a capacitor (3) connected in parallel with said rectified AC voltage for providing a DC voltage (VDC) over a load (5), characterized by a unidirectional

  12. Streaming Reduction Circuit

    NARCIS (Netherlands)

    Gerards, Marco Egbertus Theodorus; Kuper, Jan; Kokkeler, Andre B.J.; Molenkamp, Egbert

    2009-01-01

    Reduction circuits are used to reduce rows of floating point values to single values. Binary floating point operators often have deep pipelines, which may cause hazards when many consecutive rows have to be reduced. We present an algorithm by which any number of consecutive rows of arbitrary lengths

  13. A Magnetic Circuit Demonstration.

    Science.gov (United States)

    Vanderkooy, John; Lowe, June

    1995-01-01

    Presents a demonstration designed to illustrate Faraday's, Ampere's, and Lenz's laws and to reinforce the concepts through the analysis of a two-loop magnetic circuit. Can be made dramatic and challenging for sophisticated students but is suitable for an introductory course in electricity and magnetism. (JRH)

  14. A design method of oscillatory De-Qing circuit

    International Nuclear Information System (INIS)

    Feng Wenquan

    1988-01-01

    With some particular advantages the oscillatory De-Qing circuit now is widely used. However its design is very complex. By means of a quantitative analysis for this circuit a group of design formulas is obtained. According to these design formulas the maximum allowable charging inductance L c , the De-Qing network resistance R and capacitance C can easily be determined, if the PFN capacitance C N , the maximum pulse frequency F max , and percentage regulation η are given. Simple and direct formulas for specific situation are listed. Finally, a design example is given and a comparison with experimental result is made, which shows that the design method is feasible and reliable

  15. Integrated Circuit Electromagnetic Immunity Handbook

    Science.gov (United States)

    Sketoe, J. G.

    2000-08-01

    This handbook presents the results of the Boeing Company effort for NASA under contract NAS8-98217. Immunity level data for certain integrated circuit parts are discussed herein, along with analytical techniques for applying the data to electronics systems. This handbook is built heavily on the one produced in the seventies by McDonnell Douglas Astronautics Company (MDAC, MDC Report E1929 of 1 August 1978, entitled Integrated Circuit Electromagnetic Susceptibility Handbook, known commonly as the ICES Handbook, which has served countless systems designers for over 20 years). Sections 2 and 3 supplement the device susceptibility data presented in section 4 by presenting information on related material required to use the IC susceptibility information. Section 2 concerns itself with electromagnetic susceptibility analysis and serves as a guide in using the information contained in the rest of the handbook. A suggested system hardening requirements is presented in this chapter. Section 3 briefly discusses coupling and shielding considerations. For conservatism and simplicity, a worst case approach is advocated to determine the maximum amount of RF power picked up from a given field. This handbook expands the scope of the immunity data in this Handbook is to of 10 MHz to 10 GHz. However, the analytical techniques provided are applicable to much higher frequencies as well. It is expected however, that the upper frequency limit of concern is near 10 GHz. This is due to two factors; the pickup of microwave energy on system cables and wiring falls off as the square of the wavelength, and component response falls off at a rapid rate due to the effects of parasitic shunt paths for the RF energy. It should be noted also that the pickup on wires and cables does not approach infinity as the frequency decreases (as would be expected by extrapolating the square law dependence of the high frequency roll-off to lower frequencies) but levels off due to mismatch effects.

  16. Open Hardware at CERN

    CERN Multimedia

    CERN Knowledge Transfer Group

    2015-01-01

    CERN is actively making its knowledge and technology available for the benefit of society and does so through a variety of different mechanisms. Open hardware has in recent years established itself as a very effective way for CERN to make electronics designs and in particular printed circuit board layouts, accessible to anyone, while also facilitating collaboration and design re-use. It is creating an impact on many levels, from companies producing and selling products based on hardware designed at CERN, to new projects being released under the CERN Open Hardware Licence. Today the open hardware community includes large research institutes, universities, individual enthusiasts and companies. Many of the companies are actively involved in the entire process from design to production, delivering services and consultancy and even making their own products available under open licences.

  17. The LMT circuit and SPICE

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamacevicius, Arunas

    2006-01-01

    The state equations of the LMT circuit are modeled as a dedicated analogue computer circuit and solved by means of PSpice. The nonlinear part of the system is studied. Problems with the PSpice program are presented....

  18. Resistor Combinations for Parallel Circuits.

    Science.gov (United States)

    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)

  19. Detecting short circuits during assembly

    Science.gov (United States)

    Deboo, G. J.

    1980-01-01

    Detector circuit identifies shorts between bus bars of electronic equipment being wired. Detector sounds alarm and indicates which planes are shorted. Power and ground bus bars are scanned continuously until short circuit occurs.

  20. BR-5 primary circuit decontamination

    International Nuclear Information System (INIS)

    Efimov, I.A.; Nikulin, M.P.; Smirnov-Averin, A.P.; Tymosh, B.S.; Shereshkov, V.S.

    1976-01-01

    Results and methodology of steam-water and acid decontamination of the primary coolant circuit SBR-5 reactor in 1971 are discussed. Regeneration process in a cold trap of the primary coolant circuit is discussed

  1. MOS voltage automatic tuning circuit

    OpenAIRE

    李, 田茂; 中田, 辰則; 松本, 寛樹

    2004-01-01

    Abstract ###Automatic tuning circuit adjusts frequency performance to compensate for the process variation. Phase locked ###loop (PLL) is a suitable oscillator for the integrated circuit. It is a feedback system that compares the input ###phase with the output phase. It can make the output frequency equal to the input frequency. In this paper, PLL ###fomed of MOSFET's is presented.The presented circuit consists of XOR circuit, Low-pass filter and Relaxation ###Oscillator. On PSPICE simulation...

  2. Behavioral synthesis of asynchronous circuits

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard

    2005-01-01

    This thesis presents a method for behavioral synthesis of asynchronous circuits, which aims at providing a synthesis flow which uses and tranfers methods from synchronous circuits to asynchronous circuits. We move the synchronous behavioral synthesis abstraction into the asynchronous handshake...... is idle. This reduces unnecessary switching activity in the individual functional units and therefore the energy consumption of the entire circuit. A collection of behavioral synthesis algorithms have been developed allowing the designer to perform time and power constrained design space exploration...

  3. Selected collection of circuit drawings

    International Nuclear Information System (INIS)

    1977-01-01

    The many electronics circuits have been constracted in the Electronics Shop for use in nuclear experiments or other purposes of this Institute. The types of these circuits amount to about 500 items in total since 1968. This report describes the electronics circuit diagrams selected from this collection. The circuit details are not presented in this report, because these are already been published in the other technical reports. (auth.)

  4. Diode, transistor & fet circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Diode, Transistor and FET Circuits Manual is a handbook of circuits based on discrete semiconductor components such as diodes, transistors, and FETS. The book also includes diagrams and practical circuits. The book describes basic and special diode characteristics, heat wave-rectifier circuits, transformers, filter capacitors, and rectifier ratings. The text also presents practical applications of associated devices, for example, zeners, varicaps, photodiodes, or LEDs, as well as it describes bipolar transistor characteristics. The transistor can be used in three basic amplifier configuration

  5. Three-phase short circuit calculation method based on pre-computed surface for doubly fed induction generator

    Science.gov (United States)

    Ma, J.; Liu, Q.

    2018-02-01

    This paper presents an improved short circuit calculation method, based on pre-computed surface to determine the short circuit current of a distribution system with multiple doubly fed induction generators (DFIGs). The short circuit current, injected into power grid by DFIG, is determined by low voltage ride through (LVRT) control and protection under grid fault. However, the existing methods are difficult to calculate the short circuit current of DFIG in engineering practice due to its complexity. A short circuit calculation method, based on pre-computed surface, was proposed by developing the surface of short circuit current changing with the calculating impedance and the open circuit voltage. And the short circuit currents were derived by taking into account the rotor excitation and crowbar activation time. Finally, the pre-computed surfaces of short circuit current at different time were established, and the procedure of DFIG short circuit calculation considering its LVRT was designed. The correctness of proposed method was verified by simulation.

  6. Analysis of Bernstein's factorization circuit

    NARCIS (Netherlands)

    Lenstra, A.K.; Shamir, A.; Tomlinson, J.; Tromer, E.; Zheng, Y.

    2002-01-01

    In [1], Bernstein proposed a circuit-based implementation of the matrix step of the number field sieve factorization algorithm. These circuits offer an asymptotic cost reduction under the measure "construction cost x run time". We evaluate the cost of these circuits, in agreement with [1], but argue

  7. High voltage MOSFET switching circuit

    Science.gov (United States)

    McEwan, Thomas E.

    1994-01-01

    The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET.

  8. Test signal generation for analog circuits

    Directory of Open Access Journals (Sweden)

    B. Burdiek

    2003-01-01

    Full Text Available In this paper a new test signal generation approach for general analog circuits based on the variational calculus and modern control theory methods is presented. The computed transient test signals also called test stimuli are optimal with respect to the detection of a given fault set by means of a predefined merit functional representing a fault detection criterion. The test signal generation problem of finding optimal test stimuli detecting all faults form the fault set is formulated as an optimal control problem. The solution of the optimal control problem representing the test stimuli is computed using an optimization procedure. The optimization procedure is based on the necessary conditions for optimality like the maximum principle of Pontryagin and adjoint circuit equations.

  9. Neuromorphic Silicon Neuron Circuits

    Science.gov (United States)

    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

  10. Neuromorphic silicon neuron circuits

    Directory of Open Access Journals (Sweden)

    Giacomo eIndiveri

    2011-05-01

    Full Text Available 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.

  11. Integrated circuit structure

    International Nuclear Information System (INIS)

    1981-01-01

    The invention describes the fabrication of integrated circuit structures, such as read-only memory components of field-effect transistors, which may be fabricated and then maintained in inventory, and later selectively modified in accordance with a desired pattern. It is claimed that MOS depletion-mode devices in accordance with the invention can be fabricated at lower cost and at higher yields. (U.K.)

  12. Integrated Circuit Immunity

    Science.gov (United States)

    Sketoe, J. G.; Clark, Anthony

    2000-01-01

    This paper presents a DOD E3 program overview on integrated circuit immunity. The topics include: 1) EMI Immunity Testing; 2) Threshold Definition; 3) Bias Tee Function; 4) Bias Tee Calibration Set-Up; 5) EDM Test Figure; 6) EMI Immunity Levels; 7) NAND vs. and Gate Immunity; 8) TTL vs. LS Immunity Levels; 9) TP vs. OC Immunity Levels; 10) 7805 Volt Reg Immunity; and 11) Seventies Chip Set. This paper is presented in viewgraph form.

  13. Integrated coincidence circuits

    International Nuclear Information System (INIS)

    Borejko, V.F.; Grebenyuk, V.M.; Zinov, V.G.

    1976-01-01

    The description is given of two coincidence units employing integral circuits in the VISHNYA standard. The units are distinguished for the coincidence selection element which is essentially a combination of a tunnel diode and microcircuits. The output fast response of the units is at least 90 MHz in the mode of the output signal unshaped in duration and 50 MHz minimum in the mode of the output signal shaping. The resolution time of the units is dependent upon the duration of input signals

  14. Semiconductor integrated circuits

    International Nuclear Information System (INIS)

    Michel, A.E.; Schwenker, R.O.; Ziegler, J.F.

    1979-01-01

    An improved method involving ion implantation to form non-epitaxial semiconductor integrated circuits. These are made by forming a silicon substrate of one conductivity type with a recessed silicon dioxide region extending into the substrate and enclosing a portion of the silicon substrate. A beam of ions of opposite conductivity type impurity is directed at the substrate at an energy and dosage level sufficient to form a first region of opposite conductivity within the silicon dioxide region. This impurity having a concentration peak below the surface of the substrate forms a region of the one conductivity type which extends from the substrate surface into the first opposite type region to a depth between the concentration peak and the surface and forms a second region of opposite conductivity type. The method, materials and ion beam conditions are detailed. Vertical bipolar integrated circuits can be made this way when the first opposite type conductivity region will function as a collector. Also circuits with inverted bipolar devices when this first region functions as a 'buried'' emitter region. (U.K.)

  15. Interface Circuit For Printer Port

    Science.gov (United States)

    Tucker, Jerry H.; Yadlowsky, Ann B.

    1991-01-01

    Electronic circuit, called printer-port interface circuit (PPI) developed to overcome certain disadvantages of previous methods for connecting IBM PC or PC-compatible computer to other equipment. Has both reading and writing modes of operation. Very simple, requiring only six integrated circuits. Provides for moderately fast rates of transfer of data and uses existing unmodified circuit card in IBM PC. When used with appropriate software, circuit converts printer port on IBM PC, XT, AT, or compatible personal computer to general purpose, 8-bit-data, 16-bit address bus that connects to multitude of devices.

  16. Changes to the shuttle circuits

    CERN Multimedia

    GS Department

    2011-01-01

    To fit with passengers expectation, there will be some changes to the shuttle circuits as from Monday 10 October. See details on http://cern.ch/ShuttleService (on line on 7 October). Circuit No. 5 is cancelled as circuit No. 1 also stops at Bldg. 33. In order to guarantee shorter travel times, circuit No. 1 will circulate on Meyrin site only and circuit No. 2, with departures from Bldg. 33 and 500, on Prévessin site only. Site Services Section

  17. Thermionic integrated circuits: electronics for hostile environments

    International Nuclear Information System (INIS)

    Lynn, D.K.; McCormick, J.B.; MacRoberts, M.D.J.; Wilde, D.K.; Dooley, G.R.; Brown, D.R.

    1985-01-01

    Thermionic integrated circuits combine vacuum tube technology with integrated circuit techniques to form integrated vacuum triode circuits. These circuits are capable of extended operation in both high-temperature and high-radiation environments

  18. Power system with an integrated lubrication circuit

    Science.gov (United States)

    Hoff, Brian D [East Peoria, IL; Akasam, Sivaprasad [Peoria, IL; Algrain, Marcelo C [Peoria, IL; Johnson, Kris W [Washington, IL; Lane, William H [Chillicothe, IL

    2009-11-10

    A power system includes an engine having a first lubrication circuit and at least one auxiliary power unit having a second lubrication circuit. The first lubrication circuit is in fluid communication with the second lubrication circuit.

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

    Science.gov (United States)

    Imam, Imdad; Barkan, Philip

    1979-01-01

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

  20. Computer controlled motor vehicle battery circuit

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, W.R.; McAuiliffe, G.N.; Schlageter, G.A.

    1986-04-01

    This patent consists of a motor vehicle having a DC motor, a pedal biased to a released position and depressed by the driver to increase speed. An alternate switching means affects the vehicle speed control, a foot switch is operated by the pedal and operative when the pedal is depressed to close a circuit enabling energization of the alternate switching means. A microprocessor includes a program for controlling operation of the alternate switching means, the foot switch is operative when the pedal is released to open the enabling circuit. The program includes a register which is incremented with each passage of the logic and is responsive to the incremented count in the register to instruct a change in position of the alternate switching means.

  1. Integrated coherent matter wave circuits

    International Nuclear Information System (INIS)

    Ryu, C.; Boshier, M. G.

    2015-01-01

    An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. We report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through their electric polarizability. Moreover, the source of coherent matter waves is a Bose-Einstein condensate (BEC). Finally, we launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry

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

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Jing; Nagarkoti, Deepak Singh; Rajab, Khalid Z.; Hao, Yang, E-mail: y.hao@qmul.ac.uk [School of Electronic Engineering and Computer Science, Queen Mary, University of London, London, E1 4NS (United Kingdom)

    2016-06-15

    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.

  3. Tunable quantum criticality and super-ballistic transport in a "charge" Kondo circuit.

    Science.gov (United States)

    Iftikhar, Z; Anthore, A; Mitchell, A K; Parmentier, F D; Gennser, U; Ouerghi, A; Cavanna, A; Mora, C; Simon, P; Pierre, F

    2018-05-03

    Quantum phase transitions (QPTs) are ubiquitous in strongly-correlated materials. However the microscopic complexity of these systems impedes the quantitative understanding of QPTs. Here, we observe and thoroughly analyze the rich strongly-correlated physics in two profoundly dissimilar regimes of quantum criticality. With a circuit implementing a quantum simulator for the three-channel Kondo model, we reveal the universal scalings toward different low-temperature fixed points and along the multiple crossovers from quantum criticality. Notably, an unanticipated violation of the maximum conductance for ballistic free electrons is uncovered. The present charge pseudospin implementation of a Kondo impurity opens access to a broad variety of strongly-correlated phenomena. Copyright © 2018, American Association for the Advancement of Science.

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

    Directory of Open Access Journals (Sweden)

    Jing Tian

    2016-06-01

    Full Text Available 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.

  5. Testing Fixture For Microwave Integrated Circuits

    Science.gov (United States)

    Romanofsky, Robert; Shalkhauser, Kurt

    1989-01-01

    Testing fixture facilitates radio-frequency characterization of microwave and millimeter-wave integrated circuits. Includes base onto which two cosine-tapered ridge waveguide-to-microstrip transitions fastened. Length and profile of taper determined analytically to provide maximum bandwidth and minimum insertion loss. Each cosine taper provides transformation from high impedance of waveguide to characteristic impedance of microstrip. Used in conjunction with automatic network analyzer to provide user with deembedded scattering parameters of device under test. Operates from 26.5 to 40.0 GHz, but operation extends to much higher frequencies.

  6. Maximum Entropy in Drug Discovery

    Directory of Open Access Journals (Sweden)

    Chih-Yuan Tseng

    2014-07-01

    Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.

  7. Instrumentation for Sodium Circuits; Instrumentation des Circuits de Sodium

    Energy Technology Data Exchange (ETDEWEB)

    Cambillard, E. [CEA, Centre d' Etudes Nucleaires de Fontenay-aux-Roses (France); Lions, N. [CEA, Centre d' Etudes Nucleaires de Cadarache (France)

    1967-06-15

    Electromagnetic flow meters, level gauges and differential pressure gauges are among the main measurement instruments designed and tested at the Commissariat a l'Energie Atomique (CEA) for sodium reactors. The main characteristics of the flow meters used with RAPSODIE are indicated. The instruments used in this connection are of the permanent -magnet or electromagnet type (in the primary circuits). A description is given of the calibration methods employed - use is made of diaphragms or Venturi tubes as standard flow meters - and information is given on the results measured for maximum sodium flows of 400 m{sup 3}/h. Three types of continuous level gauge have been studied. Resistance gauge. Two varieties used for the 1 - and 10-MW test circuits of RAPSODIE are described. In one there is a compensation resistance along the whole height of the measuring element (the continuous gauges used with the RAPSODIE reactor are at present of this type). In the other type of gauge a device is incorporated to heat the measurement element and prevent the formation of conducting deposits (prototype sodium tests have been completed). Induction gauge. This type has two coupled coils and is fitted with a device to compensate for temperature effects. A description is given of a prototype which has been built and the results obtained in the course of sodium tests are described. Ultrasonic gauge. With this type, a transmitter is fitted on top of the outside of the sodium container; there is also a vertical wave guide, the bottom of which is immersed in the liquid metal and possesses a reflector system which returns the ultrasonic beam towards the surface. Fixed reference marks provide a permanent means of calibration and the whole apparatus is welded. This type of gauge is now being constructed. The differential pressure gauges that have been built, and used in particular with Venturi tube flow meters, are modified versions of the devices employed with the 1 - and 10-MW test circuits of

  8. Merging polygons on two-layer printed circuit board

    Directory of Open Access Journals (Sweden)

    Murov S. Yu.

    2011-12-01

    Full Text Available A method is proposed for solving the problem of connection of maximum number of isolated islands of metallized areas of the same chain, located on different layers of the printed circuit board. The method can be used in the automatic tracing of the boards.

  9. Genetic Spot Optimization for Peak Power Estimation in Large VLSI Circuits

    Directory of Open Access Journals (Sweden)

    Michael S. Hsiao

    2002-01-01

    Full Text Available Estimating peak power involves optimization of the circuit's switching function. The switching of a given gate is not only dependent on the output capacitance of the node, but also heavily dependent on the gate delays in the circuit, since multiple switching events can result from uneven circuit delay paths in the circuit. Genetic spot expansion and optimization are proposed in this paper to estimate tight peak power bounds for large sequential circuits. The optimization spot shifts and expands dynamically based on the maximum power potential (MPP of the nodes under optimization. Four genetic spot optimization heuristics are studied for sequential circuits. Experimental results showed an average of 70.7% tighter peak power bounds for large sequential benchmark circuits was achieved in short execution times.

  10. Approximative calculation of transient short-circuit currents in power-systems

    Energy Technology Data Exchange (ETDEWEB)

    Heuck, K; Rosenberger, R; Dettmann, K D; Kegel, R

    1986-08-01

    The paper shows that it is approximatively possible to calculate the transient short-circuit currents for symmetrical and asymmetrical faults in power-systems. For that purpose a simple equivalent network is found. Its error of approximation is small. For the important maximum short-circuit current limits of error are pointed out compared to VDE 0102.

  11. Dynamic pulse difference circuit

    International Nuclear Information System (INIS)

    Erickson, G.L.

    1978-01-01

    A digital electronic circuit of especial use for subtracting background activity pulses in gamma spectrometry is disclosed which comprises an up-down counter connected to count up with signal-channel pulses and to count down with background-channel pulses. A detector responsive to the count position of the up-down counter provides a signal when the up-down counter has completed one scaling sequence cycle of counts in the up direction. In an alternate embodiment, a detector responsive to the count position of the up-down counter provides a signal upon overflow of the counter

  12. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2007-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Each chapter ends with a set

  13. Electric circuits problem solver

    CERN Document Server

    REA, Editors of

    2012-01-01

    Each Problem Solver is an insightful and essential study and solution guide chock-full of clear, concise problem-solving gems. All your questions can be found in one convenient source from one of the most trusted names in reference solution guides. More useful, more practical, and more informative, these study aids are the best review books and textbook companions available. Nothing remotely as comprehensive or as helpful exists in their subject anywhere. Perfect for undergraduate and graduate studies.Here in this highly useful reference is the finest overview of electric circuits currently av

  14. Digital logic circuit test

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Gil Jung; Yang, Hong Young

    2011-03-15

    This book is about digital logic circuit test, which lists the digital basic theory, basic gate like and, or And Not gate, NAND/NOR gate such as NAND gate, NOR gate, AND and OR, logic function, EX-OR gate, adder and subtractor, decoder and encoder, multiplexer, demultiplexer, flip-flop, counter such as up/down counter modulus N counter and Reset type counter, shift register, D/A and A/D converter and two supplements list of using components and TTL manual and CMOS manual.

  15. Photonic Integrated Circuits

    Science.gov (United States)

    Krainak, Michael; Merritt, Scott

    2016-01-01

    Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.

  16. Integrated circuit cell library

    Science.gov (United States)

    Whitaker, Sterling R. (Inventor); Miles, Lowell H. (Inventor)

    2005-01-01

    According to the invention, an ASIC cell library for use in creation of custom integrated circuits is disclosed. The ASIC cell library includes some first cells and some second cells. Each of the second cells includes two or more kernel cells. The ASIC cell library is at least 5% comprised of second cells. In various embodiments, the ASIC cell library could be 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more comprised of second cells.

  17. Nano integrated circuit process

    International Nuclear Information System (INIS)

    Yoon, Yung Sup

    2004-02-01

    This book contains nine chapters, which are introduction of manufacture of semiconductor chip, oxidation such as Dry-oxidation, wet oxidation, oxidation model and oxide film, diffusion like diffusion process, diffusion equation, diffusion coefficient and diffusion system, ion implantation, including ion distribution, channeling, multiimplantation and masking and its system, sputtering such as CVD and PVD, lithography, wet etch and dry etch, interconnection and flattening like metal-silicon connection, silicide, multiple layer metal process and flattening, an integrated circuit process, including MOSFET and CMOS.

  18. Electronic logic circuits

    CERN Document Server

    Gibson, J

    2013-01-01

    Most branches of organizing utilize digital electronic systems. This book introduces the design of such systems using basic logic elements as the components. The material is presented in a straightforward manner suitable for students of electronic engineering and computer science. The book is also of use to engineers in related disciplines who require a clear introduction to logic circuits. This third edition has been revised to encompass the most recent advances in technology as well as the latest trends in components and notation. It includes a wide coverage of application specific integrate

  19. Linear integrated circuits

    CERN Document Server

    Carr, Joseph

    1996-01-01

    The linear IC market is large and growing, as is the demand for well trained technicians and engineers who understand how these devices work and how to apply them. Linear Integrated Circuits provides in-depth coverage of the devices and their operation, but not at the expense of practical applications in which linear devices figure prominently. This book is written for a wide readership from FE and first degree students, to hobbyists and professionals.Chapter 1 offers a general introduction that will provide students with the foundations of linear IC technology. From chapter 2 onwa

  20. Nano integrated circuit process

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yung Sup

    2004-02-15

    This book contains nine chapters, which are introduction of manufacture of semiconductor chip, oxidation such as Dry-oxidation, wet oxidation, oxidation model and oxide film, diffusion like diffusion process, diffusion equation, diffusion coefficient and diffusion system, ion implantation, including ion distribution, channeling, multiimplantation and masking and its system, sputtering such as CVD and PVD, lithography, wet etch and dry etch, interconnection and flattening like metal-silicon connection, silicide, multiple layer metal process and flattening, an integrated circuit process, including MOSFET and CMOS.

  1. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2011-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Ea

  2. Optoelectronics circuits manual

    CERN Document Server

    Marston, R M

    1999-01-01

    This manual is a useful single-volume guide specifically aimed at the practical design engineer, technician, and experimenter, as well as the electronics student and amateur. It deals with the subject in an easy to read, down to earth, and non-mathematical yet comprehensive manner, explaining the basic principles and characteristics of the best known devices, and presenting the reader with many practical applications and over 200 circuits. Most of the ICs and other devices used are inexpensive and readily available types, with universally recognised type numbers.The second edition

  3. Financial–real-side interactions in an extended monetary circuit with shadow banking: Loving or dangerous hugs?

    OpenAIRE

    Botta, Alberto; Caverzasi, Eugenio; Tori, Daniele

    2015-01-01

    Monetary circuit (MC) theory is one of the most interesting attempts to formally describe the functioning of a monetary production economy as centered on the concept of the flux–reflux of money. Endogenous money creation by commercial banks allows the circuit to open and firms to implement production processes. Financial markets “passively” close the circuit by intermediating savings via bond and equity issuance. Despite its natural focus on financial-real side links, the monetary circuit lit...

  4. Optically controllable molecular logic circuits

    International Nuclear Information System (INIS)

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

    2015-01-01

    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

  5. A weak current amplifier and output circuit used in nuclear weighing scales

    International Nuclear Information System (INIS)

    Sun Jinhua; Zheng Mingquan; Wang Mingqian; Jia Changchun; Jin Hanjuan; Shi Qicun; Tang Ke

    1998-01-01

    A weak current amplifier and output circuit with a maximum nonlinear error of +-0.06% has been developed. Experiments show that it can work stably and therefore be used in nuclear industrial instruments

  6. Sequential circuit design for radiation hardened multiple voltage integrated circuits

    Science.gov (United States)

    Clark, Lawrence T [Phoenix, AZ; McIver, III, John K.

    2009-11-24

    The present invention includes a radiation hardened sequential circuit, such as a bistable circuit, flip-flop or other suitable design that presents substantial immunity to ionizing radiation while simultaneously maintaining a low operating voltage. In one embodiment, the circuit includes a plurality of logic elements that operate on relatively low voltage, and a master and slave latches each having storage elements that operate on a relatively high voltage.

  7. Reconfigurable Complementary Logic Circuits with Ambipolar Organic Transistors.

    Science.gov (United States)

    Yoo, Hocheon; Ghittorelli, Matteo; Smits, Edsger C P; Gelinck, Gerwin H; Lee, Han-Koo; Torricelli, Fabrizio; Kim, Jae-Joon

    2016-10-20

    Ambipolar organic electronics offer great potential for simple and low-cost fabrication of complementary logic circuits on large-area and mechanically flexible substrates. Ambipolar transistors are ideal candidates for the simple and low-cost development of complementary logic circuits since they can operate as n-type and p-type transistors. Nevertheless, the experimental demonstration of ambipolar organic complementary circuits is limited to inverters. The control of the transistor polarity is crucial for proper circuit operation. Novel gating techniques enable to control the transistor polarity but result in dramatically reduced performances. Here we show high-performance non-planar ambipolar organic transistors with electrical control of the polarity and orders of magnitude higher performances with respect to state-of-art split-gate ambipolar transistors. Electrically reconfigurable complementary logic gates based on ambipolar organic transistors are experimentally demonstrated, thus opening up new opportunities for ambipolar organic complementary electronics.

  8. Circuit engineering principles for construction of bipolar large-scale integrated circuit storage devices and very large-scale main memory

    Science.gov (United States)

    Neklyudov, A. A.; Savenkov, V. N.; Sergeyez, A. G.

    1984-06-01

    Memories are improved by increasing speed or the memory volume on a single chip. The most effective means for increasing speeds in bipolar memories are current control circuits with the lowest extraction times for a specific power consumption (1/4 pJ/bit). The control current circuitry involves multistage current switches and circuits accelerating transient processes in storage elements and links. Circuit principles for the design of bipolar memories with maximum speeds for an assigned minimum of circuit topology are analyzed. Two main classes of storage with current control are considered: the ECL type and super-integrated injection type storage with data capacities of N = 1/4 and N 4/16, respectively. The circuits reduce logic voltage differentials and the volumes of lexical and discharge buses and control circuit buses. The limiting speed is determined by the antiinterference requirements of the memory in storage and extraction modes.

  9. Simple Cell Balance Circuit

    Science.gov (United States)

    Johnson, Steven D.; Byers, Jerry W.; Martin, James A.

    2012-01-01

    A method has been developed for continuous cell voltage balancing for rechargeable batteries (e.g. lithium ion batteries). A resistor divider chain is provided that generates a set of voltages representing the ideal cell voltage (the voltage of each cell should be as if the cells were perfectly balanced). An operational amplifier circuit with an added current buffer stage generates the ideal voltage with a very high degree of accuracy, using the concept of negative feedback. The ideal voltages are each connected to the corresponding cell through a current- limiting resistance. Over time, having the cell connected to the ideal voltage provides a balancing current that moves the cell voltage very close to that ideal level. In effect, it adjusts the current of each cell during charging, discharging, and standby periods to force the cell voltages to be equal to the ideal voltages generated by the resistor divider. The device also includes solid-state switches that disconnect the circuit from the battery so that it will not discharge the battery during storage. This solution requires relatively few parts and is, therefore, of lower cost and of increased reliability due to the fewer failure modes. Additionally, this design uses very little power. A preliminary model predicts a power usage of 0.18 W for an 8-cell battery. This approach is applicable to a wide range of battery capacities and voltages.

  10. Quantum-Circuit Refrigerator

    Science.gov (United States)

    MöTtöNen, Mikko; Tan, Kuan Y.; Masuda, Shumpei; Partanen, Matti; Lake, Russell E.; Govenius, Joonas; Silveri, Matti; Grabert, Hermann

    Quantum technology holds great potential in providing revolutionizing practical applications. However, fast and precise cooling of the functional quantum degrees of freedom on demand remains a major challenge in many solid-state implementations, such as superconducting circuits. We demonstrate direct cooling of a superconducting resonator mode using voltage-controllable quantum tunneling of electrons in a nanoscale refrigerator. In our first experiments on this type of a quantum-circuit refrigerator, we measure the drop in the mode temperature by electron thermometry at a resistor which is coupled to the resonator mode through ohmic losses. To eliminate unwanted dissipation, we remove the probe resistor and directly observe the power spectrum of the resonator output in agreement with the so-called P(E) theory. We also demonstrate in microwave reflection experiments that the internal quality factor of the resonator can be tuned by orders of magnitude. In the future, our refrigerator can be integrated with different quantum electric devices, potentially enhancing their performance. For example, it may prove useful in the initialization of superconducting quantum bits and in dissipation-assisted quantum annealing. We acknowledge European Research Council Grant SINGLEOUT (278117) and QUESS (681311) for funding.

  11. Quasi-Linear Circuit

    Science.gov (United States)

    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

  12. Arithmetic circuits for DSP applications

    CERN Document Server

    Stouraitis, Thanos

    2017-01-01

    Arithmetic Circuits for DSP Applications is a complete resource on arithmetic circuits for digital signal processing (DSP). It covers the key concepts, designs and developments of different types of arithmetic circuits, which can be used for improving the efficiency of implementation of a multitude of DSP applications. Each chapter includes various applications of the respective class of arithmetic circuits along with information on the future scope of research. Written for students, engineers, and researchers in electrical and computer engineering, this comprehensive text offers a clear understanding of different types of arithmetic circuits used for digital signal processing applications. The text includes contributions from noted researchers on a wide range of topics, including a review o circuits used in implementing basic operations like additions and multiplications; distributed arithmetic as a technique for the multiplier-less implementation of inner products for DSP applications; discussions on look ...

  13. Integrated circuit cooled turbine blade

    Science.gov (United States)

    Lee, Ching-Pang; Jiang, Nan; Um, Jae Y.; Holloman, Harry; Koester, Steven

    2017-08-29

    A turbine rotor blade includes at least two integrated cooling circuits that are formed within the blade that include a leading edge circuit having a first cavity and a second cavity and a trailing edge circuit that includes at least a third cavity located aft of the second cavity. The trailing edge circuit flows aft with at least two substantially 180-degree turns at the tip end and the root end of the blade providing at least a penultimate cavity and a last cavity. The last cavity is located along a trailing edge of the blade. A tip axial cooling channel connects to the first cavity of the leading edge circuit and the penultimate cavity of the trailing edge circuit. At least one crossover hole connects the penultimate cavity to the last cavity substantially near the tip end of the blade.

  14. Control circuit for transformer relay

    International Nuclear Information System (INIS)

    Wyatt, G.A.

    1984-01-01

    A control circuit for a transformer relay which will automatically momentarily control the transformer relay to a selected state upon energization of the control circuit. The control circuit has an energy storage element and a current director coupled in series and adapted to be coupled with the secondary winding of the transformer relay. A device for discharge is coupled across the energy storage element. The energy storage element and current director will momentarily allow a unidirectional flow of current in the secondary winding of the transformer relay upon application of energy to the control circuit. When energy is not applied to the control circuit the device for discharge will allow the energy storage element to discharge and be available for another operation of the control circuit

  15. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    60, No. 3. — journal of. March 2003 physics pp. 415–422. Maximum stellar iron core mass. F W GIACOBBE. Chicago Research Center/American Air Liquide ... iron core compression due to the weight of non-ferrous matter overlying the iron cores within large .... thermal equilibrium velocities will tend to be non-relativistic.

  16. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore. 11 refs., 4 figs

  17. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore

  18. A portable storage maximum thermometer

    International Nuclear Information System (INIS)

    Fayart, Gerard.

    1976-01-01

    A clinical thermometer storing the voltage corresponding to the maximum temperature in an analog memory is described. End of the measurement is shown by a lamp switch out. The measurement time is shortened by means of a low thermal inertia platinum probe. This portable thermometer is fitted with cell test and calibration system [fr

  19. Neutron spectra unfolding with maximum entropy and maximum likelihood

    International Nuclear Information System (INIS)

    Itoh, Shikoh; Tsunoda, Toshiharu

    1989-01-01

    A new unfolding theory has been established on the basis of the maximum entropy principle and the maximum likelihood method. This theory correctly embodies the Poisson statistics of neutron detection, and always brings a positive solution over the whole energy range. Moreover, the theory unifies both problems of overdetermined and of underdetermined. For the latter, the ambiguity in assigning a prior probability, i.e. the initial guess in the Bayesian sense, has become extinct by virtue of the principle. An approximate expression of the covariance matrix for the resultant spectra is also presented. An efficient algorithm to solve the nonlinear system, which appears in the present study, has been established. Results of computer simulation showed the effectiveness of the present theory. (author)

  20. Source-circuit design overview

    Science.gov (United States)

    Ross, R. G., Jr.

    1983-01-01

    The source circuit is the fundamental electrical building block of a large central-station array; it consists of a series-parallel network of solar cells that develops full system voltage. The array field is generally made up of a large number of parallel source circuits. Source-circuit electrical configuration is driven by a number of design considerations, which must be considered simultaneously. Array fault tolerance and hot spot heating endurance are examined in detail.

  1. NRC Information No. 90-41: Potential failure of General Electric Magne-Blast circuit breakers and AK circuit breakers

    International Nuclear Information System (INIS)

    Rossi, C.E.

    1992-01-01

    This information notice is intended to alert addressees to potential safety concerns that may result from failures of GE vertical lift (AM) and horizontal draw-out (AMH) Magne-Blast circuit breakers utilizing ML-13 operating mechanisms to open or close them and AK circuit breakers. The particular breaker failures reported herein were caused by operating problems with prop springs, snap rings and lubricating grease. GE Nuclear Energy has informed the NRC that it is aware of these problems and that GE routinely checks and corrects them if the circuit breakers are serviced at one of the four GE nuclear service centers in the US. However, the NRC is aware that some utilities may have their circuit breakers repaired or serviced at facilities other than the four GE nuclear service centers

  2. Radiation-sensitive switching circuits

    Energy Technology Data Exchange (ETDEWEB)

    Moore, J.H.; Cockshott, C.P.

    1976-03-16

    A radiation-sensitive switching circuit has a light emitting diode which supplies light to a photo-transistor, the light being interrupted from time to time. When the photo-transistor is illuminated, current builds up and when this current reaches a predetermined value, a trigger circuit changes state. The peak output of the photo-transistor is measured and the trigger circuit is arranged to change state when the output of the device is a set proportion of the peak output, so as to allow for aging of the components. The circuit is designed to control the ignition system in an automobile engine.

  3. Four-junction superconducting circuit

    Science.gov (United States)

    Qiu, Yueyin; Xiong, Wei; He, Xiao-Ling; Li, Tie-Fu; You, J. Q.

    2016-01-01

    We develop a theory for the quantum circuit consisting of a superconducting loop interrupted by four Josephson junctions and pierced by a magnetic flux (either static or time-dependent). In addition to the similarity with the typical three-junction flux qubit in the double-well regime, we demonstrate the difference of the four-junction circuit from its three-junction analogue, including its advantages over the latter. Moreover, the four-junction circuit in the single-well regime is also investigated. Our theory provides a tool to explore the physical properties of this four-junction superconducting circuit. PMID:27356619

  4. Turkish Students' Conceptions about the Simple Electric Circuits

    Science.gov (United States)

    Cepni, Salih; Keles, Esra

    2006-01-01

    In this study, the Turkish students' understanding level of electric circuits consisting of two bulbs and one battery was investigated by using open-ended questions. Two-hundred fifty students, whose ages range from 11 to 22, were chosen from five different groups at primary, secondary and university levels in Trabzon in Turkey. In analyzing…

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

    Science.gov (United States)

    Barkan, Philip; Imam, Imdad

    1978-01-01

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

  6. Mouldable all-carbon integrated circuits.

    Science.gov (United States)

    Sun, Dong-Ming; Timmermans, Marina Y; Kaskela, Antti; Nasibulin, Albert G; Kishimoto, Shigeru; Mizutani, Takashi; Kauppinen, Esko I; Ohno, Yutaka

    2013-01-01

    A variety of plastic products, ranging from those for daily necessities to electronics products and medical devices, are produced by moulding techniques. The incorporation of electronic circuits into various plastic products is limited by the brittle nature of silicon wafers. Here we report mouldable integrated circuits for the first time. The devices are composed entirely of carbon-based materials, that is, their active channels and passive elements are all fabricated from stretchable and thermostable assemblies of carbon nanotubes, with plastic polymer dielectric layers and substrates. The all-carbon thin-film transistors exhibit a mobility of 1,027 cm(2) V(-1) s(-1) and an ON/OFF ratio of 10(5). The devices also exhibit extreme biaxial stretchability of up to 18% when subjected to thermopressure forming. We demonstrate functional integrated circuits that can be moulded into a three-dimensional dome. Such mouldable electronics open new possibilities by allowing for the addition of electronic/plastic-like functionalities to plastic/electronic products, improving their designability.

  7. Maximum physical capacity testing in cancer patients undergoing chemotherapy

    DEFF Research Database (Denmark)

    Knutsen, L.; Quist, M; Midtgaard, J

    2006-01-01

    BACKGROUND: Over the past few years there has been a growing interest in the field of physical exercise in rehabilitation of cancer patients, leading to requirements for objective maximum physical capacity measurement (maximum oxygen uptake (VO(2max)) and one-repetition maximum (1RM)) to determin...... early in the treatment process. However, the patients were self-referred and thus highly motivated and as such are not necessarily representative of the whole population of cancer patients treated with chemotherapy....... in performing maximum physical capacity tests as these motivated them through self-perceived competitiveness and set a standard that served to encourage peak performance. CONCLUSION: The positive attitudes in this sample towards maximum physical capacity open the possibility of introducing physical testing...

  8. Memristor Circuits and Systems

    KAUST Repository

    Zidan, Mohammed A.

    2015-05-01

    Current CMOS-based technologies are facing design challenges related to the continuous scaling down of the minimum feature size, according to Moore’s law. Moreover, conventional computing architecture is no longer an effective way of fulfilling modern applications demands, such as big data analysis, pattern recognition, and vector processing. Therefore, there is an exigent need to shift to new technologies, at both the architecture and the device levels. Recently, memristor devices and structures attracted attention for being promising candidates for this job. Memristor device adds a new dimension for designing novel circuits and systems. In addition, high-density memristor-based crossbar is widely considered to be the essential element for future memory and bio-inspired computing systems. However, numerous challenges need to be addressed before the memristor genuinely replaces current memory and computing technologies, which is the motivation behind this research effort. In order to address the technology challenges, we begin by fabricating and modeling the memristor device. The devices fabricated at our local clean room enriched our understanding of the memristive phenomenon and enabled the experimental testing for our memristor-based circuits. Moreover, our proposed mathematical modeling for memristor behavior is an essential element for the theoretical circuit design stage. Designing and addressing the challenges of memristor systems with practical complexity, however, requires an extra step, which takes the form of a reliable and modular simulation platform. We, therefore, built a new simulation platform for the resistive crossbar, which can simulate realistic size arrays filled with real memory data. In addition, this simulation platform includes various crossbar nonidealities in order to obtain accurate simulation results. Consequently, we were able to address the significant challenges facing the high density memristor crossbar, as the building block for

  9. A dishwasher for circuits

    CERN Multimedia

    Rosaria Marraffino

    2014-01-01

    You have always been told that electronic devices fear water. However, at the Surface Mount Devices (SMD) Workshop here at CERN all the electronic assemblies are cleaned with a machine that looks like a… dishwasher.   The circuit dishwasher. Credit: Clara Nellist.  If you think the image above shows a dishwasher, you wouldn’t be completely wrong. Apart from the fact that the whole pumping system and the case itself are made entirely from stainless steel and chemical resistant materials, and the fact that it washes electrical boards instead of dishes… it works exactly like a dishwasher. It’s a professional machine (mainly used in the pharmaceutical industry) designed to clean everything that can be washed with a water-based chemical soap. This type of treatment increases the lifetime of the electronic boards and therefore the LHC's reliability by preventing corrosion problems in the severe radiation and ozone environment of the LHC tunn...

  10. Modeling cortical circuits.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Inductive circuit arrangements

    International Nuclear Information System (INIS)

    Mansfield, Peter; Coxon, R.J.

    1987-01-01

    A switched coil arrangement is connected in a bridge configuration of four switches S 1 , S 2 , S 3 and S 4 which are each shunted by diodes D 1 , D 2 , D 3 and D 4 so that current can flow in either direction through a coil L depending on the setting of the switches. A capacitor C is connected across the bridge through a switch S 5 to receive the inductive energy stored in coil L on breaking the current flow path through the coil. The electrostatic energy stored in capacitor C can then be used to supply current through the coil in the reverse direction either immediately or after a time delay. Coil L may be a superconductive coil. Losses in the circuit can be made up by a trickle charge of capacitor C from a separate supply V 2 . The device may be used in nuclear magnetic resonance imaging. (author)

  12. On Maximum Entropy and Inference

    Directory of Open Access Journals (Sweden)

    Luigi Gresele

    2017-11-01

    Full Text Available Maximum entropy is a powerful concept that entails a sharp separation between relevant and irrelevant variables. It is typically invoked in inference, once an assumption is made on what the relevant variables are, in order to estimate a model from data, that affords predictions on all other (dependent variables. Conversely, maximum entropy can be invoked to retrieve the relevant variables (sufficient statistics directly from the data, once a model is identified by Bayesian model selection. We explore this approach in the case of spin models with interactions of arbitrary order, and we discuss how relevant interactions can be inferred. In this perspective, the dimensionality of the inference problem is not set by the number of parameters in the model, but by the frequency distribution of the data. We illustrate the method showing its ability to recover the correct model in a few prototype cases and discuss its application on a real dataset.

  13. Maximum Gene-Support Tree

    Directory of Open Access Journals (Sweden)

    Yunfeng Shan

    2008-01-01

    Full Text Available Genomes and genes diversify during evolution; however, it is unclear to what extent genes still retain the relationship among species. Model species for molecular phylogenetic studies include yeasts and viruses whose genomes were sequenced as well as plants that have the fossil-supported true phylogenetic trees available. In this study, we generated single gene trees of seven yeast species as well as single gene trees of nine baculovirus species using all the orthologous genes among the species compared. Homologous genes among seven known plants were used for validation of the finding. Four algorithms—maximum parsimony (MP, minimum evolution (ME, maximum likelihood (ML, and neighbor-joining (NJ—were used. Trees were reconstructed before and after weighting the DNA and protein sequence lengths among genes. Rarely a gene can always generate the “true tree” by all the four algorithms. However, the most frequent gene tree, termed “maximum gene-support tree” (MGS tree, or WMGS tree for the weighted one, in yeasts, baculoviruses, or plants was consistently found to be the “true tree” among the species. The results provide insights into the overall degree of divergence of orthologous genes of the genomes analyzed and suggest the following: 1 The true tree relationship among the species studied is still maintained by the largest group of orthologous genes; 2 There are usually more orthologous genes with higher similarities between genetically closer species than between genetically more distant ones; and 3 The maximum gene-support tree reflects the phylogenetic relationship among species in comparison.

  14. LCLS Maximum Credible Beam Power

    International Nuclear Information System (INIS)

    Clendenin, J.

    2005-01-01

    The maximum credible beam power is defined as the highest credible average beam power that the accelerator can deliver to the point in question, given the laws of physics, the beam line design, and assuming all protection devices have failed. For a new accelerator project, the official maximum credible beam power is determined by project staff in consultation with the Radiation Physics Department, after examining the arguments and evidence presented by the appropriate accelerator physicist(s) and beam line engineers. The definitive parameter becomes part of the project's safety envelope. This technical note will first review the studies that were done for the Gun Test Facility (GTF) at SSRL, where a photoinjector similar to the one proposed for the LCLS is being tested. In Section 3 the maximum charge out of the gun for a single rf pulse is calculated. In Section 4, PARMELA simulations are used to track the beam from the gun to the end of the photoinjector. Finally in Section 5 the beam through the matching section and injected into Linac-1 is discussed

  15. An optimum design of R-C oscillatory De-Qing circuit

    International Nuclear Information System (INIS)

    Cao Dezhang; Pan Linghe; Yang Tianlu

    1990-01-01

    An optimum design of R-C oscillatory De-Qing circuit has been developed for voltage regulation of the pulse modulator. When a new coefficient T 3 /T is introduced, the selection of De-Qing circuit parameters will become quite simple and the optimum parameters can be calculated directly. The De-Qing circuit parameters calculated will be effective in the whole range of the percentage regulation η from zero to maximum design value. The limit value of η is 0.36 or 0.29, theoretically, when the time constant of the De-Qing circuit is 3RC or 5RC respectively

  16. Monolitic integrated circuit for the strobed charge-to-time converter

    International Nuclear Information System (INIS)

    Bel'skij, V.I.; Bushnin, Yu.B.; Zimin, S.A.; Punzhin, Yu.N.; Sen'ko, V.A.; Soldatov, M.M.; Tokarchuk, V.P.

    1985-01-01

    The developed and comercially produced semiconducting circuit - gating charge-to-time converter KR1101PD1 is described. The considered integrated circuit is a short pulse charge-to-time converter with integration of input current. The circuit is designed for construction of time-to-pulse analog-to-digital converters utilized in multichannel detection systems when studying complex topology processes. Input resistance of the circuit is 0.1 Ω permissible input current is 50 mA, maximum measured charge is 300-1000 pC

  17. Evaluation of Commercially Available Open Circuit Scuba Regulators

    Science.gov (United States)

    1987-08-01

    port. The second stage hit the same as that used on the X-2. :4 .- .. *,4 4 Figure 47. TABATA TR-100 The TABATA TR-100 first stage, constructed of...130 44. SPORTSWAYS X-3 ................ .. o. . k.. ...... , ........ C-133 45 . TABATA TR-100 ............................................ C-136 46...1-50 46. SPORTSWAYS X-3 ................................................... 1-51 47. TABATA TR-100 ..... ....................... s

  18. Nuclear Reactor RA Safety Report, Vol. 16, Maximum hypothetical accident

    International Nuclear Information System (INIS)

    1986-11-01

    Fault tree analysis of the maximum hypothetical accident covers the basic elements: accident initiation, phase development phases - scheme of possible accident flow. Cause of the accident initiation is the break of primary cooling pipe, heavy water system. Loss of primary coolant causes loss of pressure in the primary circuit at the coolant input in the reactor vessel. This initiates safety protection system which should automatically shutdown the reactor. Separate chapters are devoted to: after-heat removal, coolant and moderator loss; accident effects on the reactor core, effects in the reactor building, and release of radioactive wastes [sr

  19. Approximation for maximum pressure calculation in containment of PWR reactors

    International Nuclear Information System (INIS)

    Souza, A.L. de

    1989-01-01

    A correlation was developed to estimate the maximum pressure of dry containment of PWR following a Loss-of-Coolant Accident - LOCA. The expression proposed is a function of the total energy released to the containment by the primary circuit, of the free volume of the containment building and of the total surface are of the heat-conducting structures. The results show good agreement with those present in Final Safety Analysis Report - FSAR of several PWR's plants. The errors are in the order of ± 12%. (author) [pt

  20. Compact Circuit Preprocesses Accelerometer Output

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1993-01-01

    Compact electronic circuit transfers dc power to, and preprocesses ac output of, accelerometer and associated preamplifier. Incorporated into accelerometer case during initial fabrication or retrofit onto commercial accelerometer. Made of commercial integrated circuits and other conventional components; made smaller by use of micrologic and surface-mount technology.

  1. Comminution circuits for compact itabirites

    Directory of Open Access Journals (Sweden)

    Pedro Ferreira Pinto

    Full Text Available Abstract In the beneficiation of compact Itabirites, crushing and grinding account for major operational and capital costs. As such, the study and development of comminution circuits have a fundamental importance for feasibility and optimization of compact Itabirite beneficiation. This work makes a comparison between comminution circuits for compact Itabirites from the Iron Quadrangle. The circuits developed are: a crushing and ball mill circuit (CB, a SAG mill and ball mill circuit (SAB and a single stage SAG mill circuit (SSSAG. For the SAB circuit, the use of pebble crushing is analyzed (SABC. An industrial circuit for 25 million tons of run of mine was developed for each route from tests on a pilot scale (grinding and industrial scale. The energy consumption obtained for grinding in the pilot tests was compared with that reported by Donda and Bond. The SSSAG route had the lowest energy consumption, 11.8kWh/t and the SAB route had the highest energy consumption, 15.8kWh/t. The CB and SABC routes had a similar energy consumption of 14.4 kWh/t and 14.5 kWh/t respectively.

  2. Short-circuit impedance measurement

    DEFF Research Database (Denmark)

    Pedersen, Knud Ole Helgesen; Nielsen, Arne Hejde; Poulsen, Niels Kjølstad

    2003-01-01

    Methods for estimating the short-circuit impedance in the power grid are investigated for various voltage levels and situations. The short-circuit impedance is measured, preferably from naturally occurring load changes in the grid, and it is shown that such a measurement system faces different...

  3. Cell short circuit, preshort signature

    Science.gov (United States)

    Lurie, C.

    1980-01-01

    Short-circuit events observed in ground test simulations of DSCS-3 battery in-orbit operations are analyzed. Voltage signatures appearing in the data preceding the short-circuit event are evaluated. The ground test simulation is briefly described along with performance during reconditioning discharges. Results suggest that a characteristic signature develops prior to a shorting event.

  4. Enhancement of Linear Circuit Program

    DEFF Research Database (Denmark)

    Gaunholt, Hans; Dabu, Mihaela; Beldiman, Octavian

    1996-01-01

    In this report a preliminary user friendly interface has been added to the LCP2 program making it possible to describe an electronic circuit by actually drawing the circuit on the screen. Component values and other options and parameters can easily be set by the aid of the interface. The interface...

  5. Connection of comparator circuit for pseudocoincidence counting of radioactive aerosols

    International Nuclear Information System (INIS)

    Fukatko, T.; Hajek, P.; Vidra, M.

    1985-01-01

    A block diagram is presented of the radioactive aerosol measuring instrument. The first counter records electric pulses corresponding to gross alpha activity and the second indicates pseudocoincidences derived from natural radioactivity. Data from the counters are converted to analog voltages which in the comparator circuit are compared such that the mean value of the output voltage is zero insofar as artificial radioactivity is not present on the filter. The designed connection of the comparator circuit allows the permanent adjustment of the whole measuring equipment to maximum sensitivity. (E.S.)

  6. Automatic circuit analysis based on mask information

    International Nuclear Information System (INIS)

    Preas, B.T.; Lindsay, B.W.; Gwyn, C.W.

    1976-01-01

    The Circuit Mask Translator (CMAT) code has been developed which converts integrated circuit mask information into a circuit schematic. Logical operations, pattern recognition, and special functions are used to identify and interconnect diodes, transistors, capacitors, and resistances. The circuit topology provided by the translator is compatible with the input required for a circuit analysis program

  7. A memristor-based nonvolatile latch circuit

    International Nuclear Information System (INIS)

    Robinett, Warren; Pickett, Matthew; Borghetti, Julien; Xia Qiangfei; Snider, Gregory S; Medeiros-Ribeiro, Gilberto; Williams, R Stanley

    2010-01-01

    Memristive devices, which exhibit a dynamical conductance state that depends on the excitation history, can be used as nonvolatile memory elements by storing information as different conductance states. We describe the implementation of a nonvolatile synchronous flip-flop circuit that uses a nanoscale memristive device as the nonvolatile memory element. Controlled testing of the circuit demonstrated successful state storage and restoration, with an error rate of 0.1%, during 1000 power loss events. These results indicate that integration of digital logic devices and memristors could open the way for nonvolatile computation with applications in small platforms that rely on intermittent power sources. This demonstrated feasibility of tight integration of memristors with CMOS (complementary metal-oxide-semiconductor) circuitry challenges the traditional memory hierarchy, in which nonvolatile memory is only available as a large, slow, monolithic block at the bottom of the hierarchy. In contrast, the nonvolatile, memristor-based memory cell can be fast, fine-grained and small, and is compatible with conventional CMOS electronics. This threatens to upset the traditional memory hierarchy, and may open up new architectural possibilities beyond it.

  8. Generic maximum likely scale selection

    DEFF Research Database (Denmark)

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

    2007-01-01

    in this work is on applying this selection principle under a Brownian image model. This image model provides a simple scale invariant prior for natural images and we provide illustrative examples of the behavior of our scale estimation on such images. In these illustrative examples, estimation is based......The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...

  9. Theoretical modeling and equivalent electric circuit of a bimorph piezoelectric micromachined ultrasonic transducer.

    Science.gov (United States)

    Sammoura, Firas; Kim, Sang-Gook

    2012-05-01

    An electric circuit model for a circular bimorph piezoelectric micromachined ultrasonic transducer (PMUT) was developed for the first time. The model was made up of an electric mesh, which was coupled to a mechanical mesh via a transformer element. The bimorph PMUT consisted of two piezoelectric layers of the same material, having equal thicknesses, and sandwiched between three thin electrodes. The piezoelectric layers, having the same poling axis, were biased with electric potentials of the same magnitude but opposite polarity. The strain mismatches between the two layers created by the converse piezoelectric effect caused the membrane to vibrate and, hence, transmit a pressure wave. Upon receiving the echo of the acoustic wave, the membrane deformation led to the generation of electric charges as a result of the direct piezoelectric phenomenon. The membrane angular velocity and electric current were related to the applied electric field, the impinging acoustic pressure, and the moment at the edge of the membrane using two canonical equations. The transduction coefficients from the electrical to the mechanical domain and vice-versa were shown to be bilateral and the system was shown to be reversible. The circuit parameters of the derived model were extracted, including the transformer ratio, the clamped electric impedance, the spring-softening impedance, and the open-circuit mechanical impedance. The theoretical model was fully examined by generating the electrical input impedance and average plate displacement curves versus frequency under both air and water loading conditions. A PMUT composed of piezoelectric material with a lossy dielectric was also investigated and the maximum possible electroacoustical conversion efficiency was calculated.

  10. Esophagectomy - open

    Science.gov (United States)

    ... Lewis esophagectomy, Blunt esophagectomy; Esophageal cancer - esophagectomy - open; Cancer of the esophagus - esophagectomy - open ... lining of the esophagus that can lead to cancer ( Barrett esophagus ) Severe trauma Destroyed esophagus Severely damaged stomach

  11. Improved Short-Circuit Protection for Power Cells in Series

    Science.gov (United States)

    Davies, Francis

    2008-01-01

    A scheme for protection against short circuits has been devised for series strings of lithium electrochemical cells that contain built-in short-circuit protection devices, which go into a high-resistance, current-limiting state when heated by excessive current. If cells are simply connected in a long series string to obtain a high voltage and a short circuit occurs, whichever short-circuit protection device trips first is exposed to nearly the full string voltage, which, typically, is large enough to damage the device. Depending on the specific cell design, the damage can defeat the protective function, cause a dangerous internal short circuit in the affected cell, and/or cascade to other cells. In the present scheme, reverse diodes rated at a suitably high current are connected across short series sub-strings, the lengths of which are chosen so that when a short-circuit protection device is tripped, the voltage across it does not exceed its rated voltage. This scheme preserves the resetting properties of the protective devices. It provides for bypassing of cells that fail open and limits cell reversal, though not as well as does the more-expensive scheme of connecting a diode across every cell.

  12. Soft switching circuit to improve efficiency of all solid-state Marx modulator for DBDs

    Science.gov (United States)

    Liqing, TONG; Kefu, LIU; Yonggang, WANG

    2018-02-01

    For an all solid-state Marx modulator applied in dielectric barrier discharges (DBDs), hard switching results in a very low efficiency. In this paper, a series resonant soft switching circuit, which series an inductance with DBD capacitor, is proposed to reduce the power loss. The power loss of the all circuit status with hard switching was analyzed, and the maximum power loss occurred during discharging at the rising and falling edges. The power loss of the series resonant soft switching circuit was also presented. A comparative analysis of the two circuits determined that the soft switching circuit greatly reduced power loss. The experimental results also demonstrated that the soft switching circuit improved the power transmission efficiency of an all solid-state Marx modulator for DBDs by up to 3 times.

  13. Extreme Maximum Land Surface Temperatures.

    Science.gov (United States)

    Garratt, J. R.

    1992-09-01

    There are numerous reports in the literature of observations of land surface temperatures. Some of these, almost all made in situ, reveal maximum values in the 50°-70°C range, with a few, made in desert regions, near 80°C. Consideration of a simplified form of the surface energy balance equation, utilizing likely upper values of absorbed shortwave flux (1000 W m2) and screen air temperature (55°C), that surface temperatures in the vicinity of 90°-100°C may occur for dry, darkish soils of low thermal conductivity (0.1-0.2 W m1 K1). Numerical simulations confirm this and suggest that temperature gradients in the first few centimeters of soil may reach 0.5°-1°C mm1 under these extreme conditions. The study bears upon the intrinsic interest of identifying extreme maximum temperatures and yields interesting information regarding the comfort zone of animals (including man).

  14. Nanofluidic Transistor Circuits

    Science.gov (United States)

    Chang, Hsueh-Chia; Cheng, Li-Jing; Yan, Yu; Slouka, Zdenek; Senapati, Satyajyoti

    2012-02-01

    Non-equilibrium ion/fluid transport physics across on-chip membranes/nanopores is used to construct rectifying, hysteretic, oscillatory, excitatory and inhibitory nanofluidic elements. Analogs to linear resistors, capacitors, inductors and constant-phase elements were reported earlier (Chang and Yossifon, BMF 2009). Nonlinear rectifier is designed by introducing intra-membrane conductivity gradient and by asymmetric external depletion with a reverse rectification (Yossifon and Chang, PRL, PRE, Europhys Lett 2009-2011). Gating phenomenon is introduced by functionalizing polyelectrolytes whose conformation is field/pH sensitive (Wang, Chang and Zhu, Macromolecules 2010). Surface ion depletion can drive Rubinstein's microvortex instability (Chang, Yossifon and Demekhin, Annual Rev of Fluid Mech, 2012) or Onsager-Wien's water dissociation phenomenon, leading to two distinct overlimiting I-V features. Bipolar membranes exhibit an S-hysteresis due to water dissociation (Cheng and Chang, BMF 2011). Coupling the hysteretic diode with some linear elements result in autonomous ion current oscillations, which undergo classical transitions to chaos. Our integrated nanofluidic circuits are used for molecular sensing, protein separation/concentration, electrospray etc.

  15. Open access

    NARCIS (Netherlands)

    Valkenburg, P.M.

    2015-01-01

    Open access week Van 19 tot en met 25 oktober 2015 vond wereldwijd de Open Access Week plaats. Tijdens deze week werden er over de hele wereld evenementen georganiseerd waar open access een rol speelt. Ook in Nederland zijn er diverse symposia, workshops en debatten georganiseerd zoals het debat in

  16. Experimental Device for Learning of Logical Circuit Design using Integrated Circuits

    OpenAIRE

    石橋, 孝昭

    2012-01-01

    This paper presents an experimental device for learning of logical circuit design using integrated circuits and breadboards. The experimental device can be made at a low cost and can be used for many subjects such as logical circuits, computer engineering, basic electricity, electrical circuits and electronic circuits. The proposed device is effective to learn the logical circuits than the usual lecture.

  17. Variational integrators for electric circuits

    International Nuclear Information System (INIS)

    Ober-Blöbaum, Sina; Tao, Molei; Cheng, Mulin; Owhadi, Houman; Marsden, Jerrold E.

    2013-01-01

    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

  18. Integrated circuits, and design and manufacture thereof

    Science.gov (United States)

    Auracher, Stefan; Pribbernow, Claus; Hils, Andreas

    2006-04-18

    A representation of a macro for an integrated circuit layout. The representation may define sub-circuit cells of a module. The module may have a predefined functionality. The sub-circuit cells may include at least one reusable circuit cell. The reusable circuit cell may be configured such that when the predefined functionality of the module is not used, the reusable circuit cell is available for re-use.

  19. Radiation-sensitive switching circuits

    Energy Technology Data Exchange (ETDEWEB)

    Moore, J.H.; Cockshott, C.P.

    1976-03-16

    A radiation-sensitive switching circuit includes a light emitting diode which from time to time illuminates a photo-transistor, the photo-transistor serving when its output reaches a predetermined value to operate a trigger circuit. In order to allow for aging of the components, the current flow through the diode is increased when the output from the transistor falls below a known level. Conveniently, this is achieved by having a transistor in parallel with the diode, and turning the transistor off when the output from the phototransistor becomes too low. The circuit is designed to control the ignition system in an automobile engine.

  20. The Maplin electronic circuits handbook

    CERN Document Server

    Tooley, Michael

    1990-01-01

    The Maplin Electronic Circuits Handbook provides pertinent data, formula, explanation, practical guidance, theory and practical guidance in the design, testing, and construction of electronic circuits. This book discusses the developments in electronics technology techniques.Organized into 11 chapters, this book begins with an overview of the common types of passive component. This text then provides the reader with sufficient information to make a correct selection of passive components for use in the circuits. Other chapters consider the various types of the most commonly used semiconductor

  1. Secure integrated circuits and systems

    CERN Document Server

    Verbauwhede, Ingrid MR

    2010-01-01

    On any advanced integrated circuit or 'system-on-chip' there is a need for security. In many applications the actual implementation has become the weakest link in security rather than the algorithms or protocols. The purpose of the book is to give the integrated circuits and systems designer an insight into the basics of security and cryptography from the implementation point of view. As a designer of integrated circuits and systems it is important to know both the state-of-the-art attacks as well as the countermeasures. Optimizing for security is different from optimizations for speed, area,

  2. INTEGRATED SENSOR EVALUATION CIRCUIT AND METHOD FOR OPERATING SAID CIRCUIT

    OpenAIRE

    Krüger, Jens; Gausa, Dominik

    2015-01-01

    WO15090426A1 Sensor evaluation device and method for operating said device Integrated sensor evaluation circuit for evaluating a sensor signal (14) received from a sensor (12), having a first connection (28a) for connection to the sensor and a second connection (28b) for connection to the sensor. The integrated sensor evaluation circuit comprises a configuration data memory (16) for storing configuration data which describe signal properties of a plurality of sensor control signals (26a-c). T...

  3. Superconducting quantum circuits theory and application

    Science.gov (United States)

    Deng, Xiuhao

    states. The model and toolbox are engineered with a superconducting quantum circuit where two superconducting resonators are coupled via the UQDP circuit. Using fourth order perturbation theory one can realize a complete set of quantum operations between these two photon modes. This helps open a new field to treat photon modes as qubits. Additional, a three-wave mixing scheme using phase qubits permits one to engineer the coupling Hamiltonian using a phase qubit as a tunable coupler. Along with Feynman's idea using quantum to simulate quantum, superconducting quantum simulators have been studied intensively recently. Taking the advantage of mesoscopic size of superconducting circuit and local tunability, we came out the idea to simulate quantum phase transition due to disorder. Our first paper was to propose a superconducting quantum simulator of Bose-Hubbard model to do site-wise manipulation and observe Mott-insulator to superfluid phase transition. The side-band cooling of an array of superconducting resonators is solved after the paper was published. In light of the developed technology in manipulating quantum information with superconducting circuit, one can couple other quantum oscillator system to superconducting resonators in order manipulation of its quantum states or parametric amplification of weak quantum signal. A theory that works for different coupling schemes has been studied in chapter 5. This will be a platform for further research.

  4. System for memorizing maximum values

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1992-08-01

    The invention discloses a system capable of memorizing maximum sensed values. The system includes conditioning circuitry which receives the analog output signal from a sensor transducer. The conditioning circuitry rectifies and filters the analog signal and provides an input signal to a digital driver, which may be either linear or logarithmic. The driver converts the analog signal to discrete digital values, which in turn triggers an output signal on one of a plurality of driver output lines n. The particular output lines selected is dependent on the converted digital value. A microfuse memory device connects across the driver output lines, with n segments. Each segment is associated with one driver output line, and includes a microfuse that is blown when a signal appears on the associated driver output line.

  5. Remarks on the maximum luminosity

    Science.gov (United States)

    Cardoso, Vitor; Ikeda, Taishi; Moore, Christopher J.; Yoo, Chul-Moon

    2018-04-01

    The quest for fundamental limitations on physical processes is old and venerable. Here, we investigate the maximum possible power, or luminosity, that any event can produce. We show, via full nonlinear simulations of Einstein's equations, that there exist initial conditions which give rise to arbitrarily large luminosities. However, the requirement that there is no past horizon in the spacetime seems to limit the luminosity to below the Planck value, LP=c5/G . Numerical relativity simulations of critical collapse yield the largest luminosities observed to date, ≈ 0.2 LP . We also present an analytic solution to the Einstein equations which seems to give an unboundedly large luminosity; this will guide future numerical efforts to investigate super-Planckian luminosities.

  6. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-09-07

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  7. Scintillation counter, maximum gamma aspect

    International Nuclear Information System (INIS)

    Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  8. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yi; Zhao, Shiguang; Gao, Xin

    2014-01-01

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

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

    Directory of Open Access Journals (Sweden)

    Mustafa Berkant SELEK

    2008-02-01

    Full Text Available In this study, a new microcontroller circuit was designed and new computer software was implemented to control power flow currents of renewable energy system, which is established in Solar Energy Institute, Ege University, Bornova, Izmir, Turkey. PIC18F452 microcontroller based electronic circuit was designed to control another electronic circuit that includes power electronic switching components. Readily available standard control circuits are designed for switching single level inverters. In contrary, implemented circuit allows to switch multilevel inverters. In addition, because the efficiency of solar energy panels is considerably low, solar panels should be operated under the maximum power point (MPP. Therefore, MPP algorithm is included in the designed control circuit. Next, the control circuit also includes a serial communication interface based on RS232 standard. Using this interface enables the user to choose all functions available in the control circuit and take status report via computer software. Last, a general purpose command set was designed to establish communication between the computer software and the microcontroller-based control circuit. As a result, it is aimed that this study supply a basis for the researchers who want to develop own control circuits or more visual software.

  10. Quantum circuit behaviour

    International Nuclear Information System (INIS)

    Poulton, D.

    1989-09-01

    Single electron tunnelling in multiply connected weak link systems is considered. Using a second quantised approach the tunnel current, in both normal and superconducting systems, using perturbation theory, is derived. The tunnel currents are determined as a function of an Aharanov-Bohm phase (acquired by the electrons). Using these results, the multiply connected system is then discussed when coupled to a resonant LC circuit. The resulting dynamics of this composite system are then determined. In the superconducting case the results are compared and contrasted with flux mode behaviour seen in large superconducting weak link rings. Systems in which the predicted dynamics may be seen are also discussed. In analogy to the electron tunnelling analysis, the tunnelling of magnetic flux quanta through the weak link is also considered. Here, the voltage across the weak link, due to flux tunnelling, is determined as a function of an externally applied current. This is done for both singly and multiply connected flux systems. The results are compared and contrasted with charge mode behaviour seen in superconducting weak link systems. Finally, the behaviour of simple quantum fluids is considered when subject to an external rotation. Using a microscopic analysis it is found that the microscopic quantum behaviour of the particles is manifest on a macroscopic level. Results are derived for bosonic, fermionic and BCS pair-type systems. The connection between flux quantisation in electromagnetic systems is also made. Using these results, the dynamics of such a quantum fluid is considered when coupled to a rotating torsional oscillator. The results are compared with those found in SQUID devices. A model is also presented which discusses the possible excited state dynamics of such a fluid. (author)

  11. Open Content in Open Context

    Science.gov (United States)

    Kansa, Sarah Whitcher; Kansa, Eric C.

    2007-01-01

    This article presents the challenges and rewards of sharing research content through a discussion of Open Context, a new open access data publication system for field sciences and museum collections. Open Context is the first data repository of its kind, allowing self-publication of research data, community commentary through tagging, and clear…

  12. A maximum power point tracking algorithm for photovoltaic applications

    Science.gov (United States)

    Nelatury, Sudarshan R.; Gray, Robert

    2013-05-01

    The voltage and current characteristic of a photovoltaic (PV) cell is highly nonlinear and operating a PV cell for maximum power transfer has been a challenge for a long time. Several techniques have been proposed to estimate and track the maximum power point (MPP) in order to improve the overall efficiency of a PV panel. A strategic use of the mean value theorem permits obtaining an analytical expression for a point that lies in a close neighborhood of the true MPP. But hitherto, an exact solution in closed form for the MPP is not published. This problem can be formulated analytically as a constrained optimization, which can be solved using the Lagrange method. This method results in a system of simultaneous nonlinear equations. Solving them directly is quite difficult. However, we can employ a recursive algorithm to yield a reasonably good solution. In graphical terms, suppose the voltage current characteristic and the constant power contours are plotted on the same voltage current plane, the point of tangency between the device characteristic and the constant power contours is the sought for MPP. It is subject to change with the incident irradiation and temperature and hence the algorithm that attempts to maintain the MPP should be adaptive in nature and is supposed to have fast convergence and the least misadjustment. There are two parts in its implementation. First, one needs to estimate the MPP. The second task is to have a DC-DC converter to match the given load to the MPP thus obtained. Availability of power electronics circuits made it possible to design efficient converters. In this paper although we do not show the results from a real circuit, we use MATLAB to obtain the MPP and a buck-boost converter to match the load. Under varying conditions of load resistance and irradiance we demonstrate MPP tracking in case of a commercially available solar panel MSX-60. The power electronics circuit is simulated by PSIM software.

  13. Transistor and integrated circuit manufacture

    International Nuclear Information System (INIS)

    Colman, D.

    1978-01-01

    This invention relates to the manufacture of transistors and integrated circuits by ion bombardment techniques and is particularly, but not exclusively, of value in the manufacture of so-called integrated injection logic circuitry. (author)

  14. Time domain analog circuit simulation

    NARCIS (Netherlands)

    Fijnvandraat, J.G.; Houben, S.H.M.J.; Maten, ter E.J.W.; Peters, J.M.F.

    2006-01-01

    Recent developments of new methods for simulating electric circuits are described. Emphasis is put on methods that fit existing datastructures for backward differentiation formulae methods. These methods can be modified to apply to hierarchically organized datastructures, which allows for efficient

  15. Circuit design on plastic foils

    CERN Document Server

    Raiteri, Daniele; Roermund, Arthur H M

    2015-01-01

    This book illustrates a variety of circuit designs on plastic foils and provides all the information needed to undertake successful designs in large-area electronics.  The authors demonstrate architectural, circuit, layout, and device solutions and explain the reasons and the creative process behind each. Readers will learn how to keep under control large-area technologies and achieve robust, reliable circuit designs that can face the challenges imposed by low-cost low-temperature high-throughput manufacturing.   • Discusses implications of problems associated with large-area electronics and compares them to standard silicon; • Provides the basis for understanding physics and modeling of disordered material; • Includes guidelines to quickly setup the basic CAD tools enabling efficient and reliable designs; • Illustrates practical solutions to cope with hard/soft faults, variability, mismatch, aging and bias stress at architecture, circuit, layout, and device levels.

  16. Discharge quenching circuit for counters

    International Nuclear Information System (INIS)

    Karasik, A.S.

    1982-01-01

    A circuit for quenching discharges in gas-discharge detectors with working voltage of 3-5 kV based on transistors operating in the avalanche mode is described. The quenching circuit consists of a coordinating emitter follower, amplifier-shaper for avalanche key cascade control which changes potential on the counter electrodes and a shaper of discharge quenching duration. The emitter follower is assembled according to a widely used flowsheet with two transistors. The circuit permits to obtain a rectangular quenching pulse with front of 100 ns and an amplitude of up to 3.2 kV at duration of 500 μm-8 ms. Application of the quenching circuit described permits to obtain countering characteristics with the slope less than or equal to 0.02%/V and plateau extent greater than or equal to 300 V [ru

  17. Transistor and integrated circuit manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Colman, D

    1978-09-27

    This invention relates to the manufacture of transistors and integrated circuits by ion bombardment techniques and is particularly, but not exclusively, of value in the manufacture of so-called integrated injection logic circuitry.

  18. Ignition circuit for combustion engines

    Energy Technology Data Exchange (ETDEWEB)

    Becker, H W

    1977-05-26

    The invention refers to the ignition circuit for combustion engines, which are battery fed. The circuit contains a transistor and an oscillator to produce an output voltage on the secondary winding of an output transformer to supply an ignition current. The plant is controlled by an interrupter. The purpose of the invention is to form such a circuit that improved sparks for ignition are produced, on the one hand, and that on the other hand, the plant can continue to function after loss of the oscillator. The problem is solved by the battery and the secondary winding of the output transformers of the oscillator are connected via a rectifier circuit to produce a resultant total voltage with the ignition coil from the battery voltage and the rectified pulsating oscillator output.

  19. Circuit breaker and bus

    International Nuclear Information System (INIS)

    Vogel, H.F.

    1978-01-01

    Two close-open operations are required each pulse cycle at approximately 3 MA with the breaker in series with the burn supply, both forming a leg in parallel with the E-coil and the homopolar. To conduct the 3-MA current, approximately 30 breaker units are connected in parallel. Each unit is equipped with a counterpulse capacitor bank, and the bus for the 30 units is provided with a common saturable reactor core made of strip steel wound around the bus. Oil breakers of a special design are chosen because of their high arc resistance facilitating the current transfer to the homopolar machine and for obtaining precision timing in opening and closing of the contacts. The precision timing is achieved by a shock wave method with the oil serving as hydraulic medium. Each of the parallel breaker units possesses two sets of contacts, a stationary and a transient one. A 1-mΩ resistor in series with the transient contacts of each breaker unit is to improve the current sharing. The bus consists of room temperature copper, stranded and transposed to help provide current equalization under transient conditions

  20. Weak openness and almost openness

    Directory of Open Access Journals (Sweden)

    David A. Rose

    1984-01-01

    Full Text Available Weak openness and almost openness for arbitrary functions between topological spaces are defined as duals to the weak continuity of Levine and the almost continuity of Husain respectively. Independence of these two openness conditions is noted and comparison is made between these and the almost openness of Singal and Singal. Some results dual to those known for weak continuity and almost continuity are obtained. Nearly almost openness is defined and used to obtain an improved link from weak continuity to almost continuity.

  1. Reverse engineering of integrated circuits

    Science.gov (United States)

    Chisholm, Gregory H.; Eckmann, Steven T.; Lain, Christopher M.; Veroff, Robert L.

    2003-01-01

    Software and a method therein to analyze circuits. The software comprises several tools, each of which perform particular functions in the Reverse Engineering process. The analyst, through a standard interface, directs each tool to the portion of the task to which it is most well suited, rendering previously intractable problems solvable. The tools are generally used iteratively to produce a successively more abstract picture of a circuit, about which incomplete a priori knowledge exists.

  2. Engineering genetic circuit interactions within and between synthetic minimal cells

    Science.gov (United States)

    Adamala, Katarzyna P.; Martin-Alarcon, Daniel A.; Guthrie-Honea, Katriona R.; Boyden, Edward S.

    2017-05-01

    Genetic circuits and reaction cascades are of great importance for synthetic biology, biochemistry and bioengineering. An open question is how to maximize the modularity of their design to enable the integration of different reaction networks and to optimize their scalability and flexibility. One option is encapsulation within liposomes, which enables chemical reactions to proceed in well-isolated environments. Here we adapt liposome encapsulation to enable the modular, controlled compartmentalization of genetic circuits and cascades. We demonstrate that it is possible to engineer genetic circuit-containing synthetic minimal cells (synells) to contain multiple-part genetic cascades, and that these cascades can be controlled by external signals as well as inter-liposomal communication without crosstalk. We also show that liposomes that contain different cascades can be fused in a controlled way so that the products of incompatible reactions can be brought together. Synells thus enable a more modular creation of synthetic biology cascades, an essential step towards their ultimate programmability.

  3. Maximum entropy and Bayesian methods

    International Nuclear Information System (INIS)

    Smith, C.R.; Erickson, G.J.; Neudorfer, P.O.

    1992-01-01

    Bayesian probability theory and Maximum Entropy methods are at the core of a new view of scientific inference. These 'new' ideas, along with the revolution in computational methods afforded by modern computers allow astronomers, electrical engineers, image processors of any type, NMR chemists and physicists, and anyone at all who has to deal with incomplete and noisy data, to take advantage of methods that, in the past, have been applied only in some areas of theoretical physics. The title workshops have been the focus of a group of researchers from many different fields, and this diversity is evident in this book. There are tutorial and theoretical papers, and applications in a very wide variety of fields. Almost any instance of dealing with incomplete and noisy data can be usefully treated by these methods, and many areas of theoretical research are being enhanced by the thoughtful application of Bayes' theorem. Contributions contained in this volume present a state-of-the-art overview that will be influential and useful for many years to come

  4. Receiver Gain Modulation Circuit

    Science.gov (United States)

    Jones, Hollis; Racette, Paul; Walker, David; Gu, Dazhen

    2011-01-01

    A receiver gain modulation circuit (RGMC) was developed that modulates the power gain of the output of a radiometer receiver with a test signal. As the radiometer receiver switches between calibration noise references, the test signal is mixed with the calibrated noise and thus produces an ensemble set of measurements from which ensemble statistical analysis can be used to extract statistical information about the test signal. The RGMC is an enabling technology of the ensemble detector. As a key component for achieving ensemble detection and analysis, the RGMC has broad aeronautical and space applications. The RGMC can be used to test and develop new calibration algorithms, for example, to detect gain anomalies, and/or correct for slow drifts that affect climate-quality measurements over an accelerated time scale. A generalized approach to analyzing radiometer system designs yields a mathematical treatment of noise reference measurements in calibration algorithms. By treating the measurements from the different noise references as ensemble samples of the receiver state, i.e. receiver gain, a quantitative description of the non-stationary properties of the underlying receiver fluctuations can be derived. Excellent agreement has been obtained between model calculations and radiometric measurements. The mathematical formulation is equivalent to modulating the gain of a stable receiver with an externally generated signal and is the basis for ensemble detection and analysis (EDA). The concept of generating ensemble data sets using an ensemble detector is similar to the ensemble data sets generated as part of ensemble empirical mode decomposition (EEMD) with exception of a key distinguishing factor. EEMD adds noise to the signal under study whereas EDA mixes the signal with calibrated noise. It is mixing with calibrated noise that permits the measurement of temporal-functional variability of uncertainty in the underlying process. The RGMC permits the evaluation of EDA by

  5. Circuit switched optical networks

    DEFF Research Database (Denmark)

    Kloch, Allan

    2003-01-01

    Some of the most important components required for enabling optical networking are investigated through both experiments and modelling. These all-optical components are the wavelength converter, the regenerator and the space switch. When these devices become "off-the-shelf" products, optical cross......, it is expected that the optical solution will offer an economical benefit for hight bit rate networks. This thesis begins with a discussion of the expected impact on communications systems from the rapidly growing IP traffic, which is expected to become the dominant source for traffic. IP traffic has some...... characteristics, which are best supported by an optical network. The interest for such an optical network is exemplified by the formation of the ACTS OPEN project which aim was to investigate the feasibility of an optical network covering Europe. Part of the work presented in this thesis is carried out within...

  6. On an Objective Basis for the Maximum Entropy Principle

    Directory of Open Access Journals (Sweden)

    David J. Miller

    2015-01-01

    Full Text Available In this letter, we elaborate on some of the issues raised by a recent paper by Neapolitan and Jiang concerning the maximum entropy (ME principle and alternative principles for estimating probabilities consistent with known, measured constraint information. We argue that the ME solution for the “problematic” example introduced by Neapolitan and Jiang has stronger objective basis, rooted in results from information theory, than their alternative proposed solution. We also raise some technical concerns about the Bayesian analysis in their work, which was used to independently support their alternative to the ME solution. The letter concludes by noting some open problems involving maximum entropy statistical inference.

  7. Maximum length scale in density based topology optimization

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Wang, Fengwen

    2017-01-01

    The focus of this work is on two new techniques for imposing maximum length scale in topology optimization. Restrictions on the maximum length scale provide designers with full control over the optimized structure and open possibilities to tailor the optimized design for broader range...... of manufacturing processes by fulfilling the associated technological constraints. One of the proposed methods is based on combination of several filters and builds on top of the classical density filtering which can be viewed as a low pass filter applied to the design parametrization. The main idea...

  8. Maximum entropy principal for transportation

    International Nuclear Information System (INIS)

    Bilich, F.; Da Silva, R.

    2008-01-01

    In this work we deal with modeling of the transportation phenomenon for use in the transportation planning process and policy-impact studies. The model developed is based on the dependence concept, i.e., the notion that the probability of a trip starting at origin i is dependent on the probability of a trip ending at destination j given that the factors (such as travel time, cost, etc.) which affect travel between origin i and destination j assume some specific values. The derivation of the solution of the model employs the maximum entropy principle combining a priori multinomial distribution with a trip utility concept. This model is utilized to forecast trip distributions under a variety of policy changes and scenarios. The dependence coefficients are obtained from a regression equation where the functional form is derived based on conditional probability and perception of factors from experimental psychology. The dependence coefficients encode all the information that was previously encoded in the form of constraints. In addition, the dependence coefficients encode information that cannot be expressed in the form of constraints for practical reasons, namely, computational tractability. The equivalence between the standard formulation (i.e., objective function with constraints) and the dependence formulation (i.e., without constraints) is demonstrated. The parameters of the dependence-based trip-distribution model are estimated, and the model is also validated using commercial air travel data in the U.S. In addition, policy impact analyses (such as allowance of supersonic flights inside the U.S. and user surcharge at noise-impacted airports) on air travel are performed.

  9. Spectral Purity Enhancement via Polyphase Multipath Circuits

    NARCIS (Netherlands)

    Mensink, E.; Klumperink, Eric A.M.; Nauta, Bram

    2004-01-01

    The central question of this paper is: can we enhance the spectral purity of nonlinear circuits by using polyphase multipath circuits? The basic idea behind polyphase multipath circuits is to split the nonlinear circuits into two or more paths and exploit phase differences between these paths to

  10. Distortion Cancellation via Polyphase Multipath Circuits

    NARCIS (Netherlands)

    Mensink, E.; Klumperink, Eric A.M.; Nauta, Bram

    The central question of this paper is: can we enhance the spectral purity of nonlinear circuits with the help of polyphase multipath circuits. Polyphase multipath circuits are circuits with two or more paths that exploit phase differences between the paths to cancel unwanted signals. It turns out

  11. Dynamic theory for the mesoscopic electric circuit

    International Nuclear Information System (INIS)

    Chen Bin; Shen Xiaojuan; Li Youquan; Sun LiLy; Yin Zhujian

    2005-01-01

    The quantum theory for mesoscopic electric circuit with charge discreteness is briefly described. The minibands of quasienergy in LC design mesoscopic electric circuit have been found. In the mesoscopic 'pure' inductance design circuit, just like in the mesoscopic metallic rings, the quantum dynamic characteristics have been obtained explicitly. In the 'pure' capacity design circuit, the Coulomb blockade had also been addressed

  12. Multi-Layer E-Textile Circuits

    Science.gov (United States)

    Dunne, Lucy E.; Bibeau, Kaila; Mulligan, Lucie; Frith, Ashton; Simon, Cory

    2012-01-01

    Stitched e-textile circuits facilitate wearable, flexible, comfortable wearable technology. However, while stitched methods of e-textile circuits are common, multi-layer circuit creation remains a challenge. Here, we present methods of stitched multi-layer circuit creation using accessible tools and techniques.

  13. Open hardware for open science

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    Inspired by the open source software movement, the Open Hardware Repository was created to enable hardware developers to share the results of their R&D activities. The recently published CERN Open Hardware Licence offers the legal framework to support this knowledge and technology exchange.   Two years ago, a group of electronics designers led by Javier Serrano, a CERN engineer, working in experimental physics laboratories created the Open Hardware Repository (OHR). This project was initiated in order to facilitate the exchange of hardware designs across the community in line with the ideals of “open science”. The main objectives include avoiding duplication of effort by sharing results across different teams that might be working on the same need. “For hardware developers, the advantages of open hardware are numerous. For example, it is a great learning tool for technologies some developers would not otherwise master, and it avoids unnecessary work if someone ha...

  14. Accurate Maximum Power Tracking in Photovoltaic Systems Affected by Partial Shading

    Directory of Open Access Journals (Sweden)

    Pierluigi Guerriero

    2015-01-01

    Full Text Available A maximum power tracking algorithm exploiting operating point information gained on individual solar panels is presented. The proposed algorithm recognizes the presence of multiple local maxima in the power voltage curve of a shaded solar field and evaluates the coordinated of the absolute maximum. The effectiveness of the proposed approach is evidenced by means of circuit level simulation and experimental results. Experiments evidenced that, in comparison with a standard perturb and observe algorithm, we achieve faster convergence in normal operating conditions (when the solar field is uniformly illuminated and we accurately locate the absolute maximum power point in partial shading conditions, thus avoiding the convergence on local maxima.

  15. Open Access

    Science.gov (United States)

    Suber, Peter

    2012-01-01

    The Internet lets us share perfect copies of our work with a worldwide audience at virtually no cost. We take advantage of this revolutionary opportunity when we make our work "open access": digital, online, free of charge, and free of most copyright and licensing restrictions. Open access is made possible by the Internet and copyright-holder…

  16. Open innovation

    DEFF Research Database (Denmark)

    Bogers, Marcel; Chesbrough, Henry; Moedas, Carlos

    2018-01-01

    Open innovation is now a widely used concept in academia, business, and policy making. This article describes the state of open innovation at the intersection of research, practice, and policy. It discusses some key trends (e.g., digital transformation), challenges (e.g., uncertainty...

  17. Mammographic image restoration using maximum entropy deconvolution

    International Nuclear Information System (INIS)

    Jannetta, A; Jackson, J C; Kotre, C J; Birch, I P; Robson, K J; Padgett, R

    2004-01-01

    An image restoration approach based on a Bayesian maximum entropy method (MEM) has been applied to a radiological image deconvolution problem, that of reduction of geometric blurring in magnification mammography. The aim of the work is to demonstrate an improvement in image spatial resolution in realistic noisy radiological images with no associated penalty in terms of reduction in the signal-to-noise ratio perceived by the observer. Images of the TORMAM mammographic image quality phantom were recorded using the standard magnification settings of 1.8 magnification/fine focus and also at 1.8 magnification/broad focus and 3.0 magnification/fine focus; the latter two arrangements would normally give rise to unacceptable geometric blurring. Measured point-spread functions were used in conjunction with the MEM image processing to de-blur these images. The results are presented as comparative images of phantom test features and as observer scores for the raw and processed images. Visualization of high resolution features and the total image scores for the test phantom were improved by the application of the MEM processing. It is argued that this successful demonstration of image de-blurring in noisy radiological images offers the possibility of weakening the link between focal spot size and geometric blurring in radiology, thus opening up new approaches to system optimization

  18. Last Glacial Maximum Salinity Reconstruction

    Science.gov (United States)

    Homola, K.; Spivack, A. J.

    2016-12-01

    It has been previously demonstrated that salinity can be reconstructed from sediment porewater. The goal of our study is to reconstruct high precision salinity during the Last Glacial Maximum (LGM). Salinity is usually determined at high precision via conductivity, which requires a larger volume of water than can be extracted from a sediment core, or via chloride titration, which yields lower than ideal precision. It has been demonstrated for water column samples that high precision density measurements can be used to determine salinity at the precision of a conductivity measurement using the equation of state of seawater. However, water column seawater has a relatively constant composition, in contrast to porewater, where variations from standard seawater composition occur. These deviations, which affect the equation of state, must be corrected for through precise measurements of each ion's concentration and knowledge of apparent partial molar density in seawater. We have developed a density-based method for determining porewater salinity that requires only 5 mL of sample, achieving density precisions of 10-6 g/mL. We have applied this method to porewater samples extracted from long cores collected along a N-S transect across the western North Atlantic (R/V Knorr cruise KN223). Density was determined to a precision of 2.3x10-6 g/mL, which translates to salinity uncertainty of 0.002 gms/kg if the effect of differences in composition is well constrained. Concentrations of anions (Cl-, and SO4-2) and cations (Na+, Mg+, Ca+2, and K+) were measured. To correct salinities at the precision required to unravel LGM Meridional Overturning Circulation, our ion precisions must be better than 0.1% for SO4-/Cl- and Mg+/Na+, and 0.4% for Ca+/Na+, and K+/Na+. Alkalinity, pH and Dissolved Inorganic Carbon of the porewater were determined to precisions better than 4% when ratioed to Cl-, and used to calculate HCO3-, and CO3-2. Apparent partial molar densities in seawater were

  19. Maximum Parsimony on Phylogenetic networks

    Science.gov (United States)

    2012-01-01

    Background Phylogenetic networks are generalizations of phylogenetic trees, that are used to model evolutionary events in various contexts. Several different methods and criteria have been introduced for reconstructing phylogenetic trees. Maximum Parsimony is a character-based approach that infers a phylogenetic tree by minimizing the total number of evolutionary steps required to explain a given set of data assigned on the leaves. Exact solutions for optimizing parsimony scores on phylogenetic trees have been introduced in the past. Results In this paper, we define the parsimony score on networks as the sum of the substitution costs along all the edges of the network; and show that certain well-known algorithms that calculate the optimum parsimony score on trees, such as Sankoff and Fitch algorithms extend naturally for networks, barring conflicting assignments at the reticulate vertices. We provide heuristics for finding the optimum parsimony scores on networks. Our algorithms can be applied for any cost matrix that may contain unequal substitution costs of transforming between different characters along different edges of the network. We analyzed this for experimental data on 10 leaves or fewer with at most 2 reticulations and found that for almost all networks, the bounds returned by the heuristics matched with the exhaustively determined optimum parsimony scores. Conclusion The parsimony score we define here does not directly reflect the cost of the best tree in the network that displays the evolution of the character. However, when searching for the most parsimonious network that describes a collection of characters, it becomes necessary to add additional cost considerations to prefer simpler structures, such as trees over networks. The parsimony score on a network that we describe here takes into account the substitution costs along the additional edges incident on each reticulate vertex, in addition to the substitution costs along the other edges which are

  20. Instrumentation and test gear circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Instrumentation and Test Gear Circuits Manual provides diagrams, graphs, tables, and discussions of several types of practical circuits. The practical circuits covered in this book include attenuators, bridges, scope trace doublers, timebases, and digital frequency meters. Chapter 1 discusses the basic instrumentation and test gear principles. Chapter 2 deals with the design of passive attenuators, and Chapter 3 with passive and active filter circuits. The subsequent chapters tackle 'bridge' circuits, analogue and digital metering techniques and circuitry, signal and waveform generation, and p