12,488 research outputs found

    Reduced 30% scanning time 3D multiplexer integrated circuit applied to large array format 20KHZ frequency inkjet print heads

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    Enhancement of the number and array density of nozzles within an inkjet head chip is one of the keys to raise the printing speed and printing resolutions. However, traditional 2D architecture of driving circuits can not meet the requirement for high scanning speed and low data accessing points when nozzle numbers greater than 1000. This paper proposes a novel architecture of high-selection-speed three-dimensional data registration for inkjet applications. With the configuration of three-dimensional data registration, the number of data accessing points as well as the scanning lines can be greatly reduced for large array inkjet printheads with nozzles numbering more than 1000. This IC (Integrated Circuit) architecture involves three-dimensional multiplexing with the provision of a gating transistor for each ink firing resistor, where ink firing resistors are triggered only by the selection of their associated gating transistors. Three signals: selection (S), address (A), and power supply (P), are employed together to activate a nozzle for droplet ejection. The smart printhead controller has been designed by a 0.35 um CMOS process with a total circuit area, 2500 x 500 microm2, which is 80% of the cirucuit area by 2D configuration for 1000 nozzles. Experiment results demonstrate the functionality of the fabricated IC in operation, signal transmission and a potential to control more than 1000 nozzles with only 31 data access points and reduced 30% scanning time.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

    A study of microwave downcoverters operating in the K sub u band

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    A computer program for parametric amplifier design is developed with special emphasis on practical design considerations for microwave integrated circuit degenerate amplifiers. Precision measurement techniques are developed to obtain a more realistic varactor equivalent circuit. The existing theory of a parametric amplifier is modified to include the equivalent circuit, and microwave properties, such as loss characteristics and circuit discontinuities are investigated

    Fast-Light in a Photorefractive Crystal for Gravitational Wave Detection

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    We demonstrate superluminal light propagation using two frequency multiplexed pump beams to produce a gain doublet in a photorefractive crystal of Ce:BaTiO3. The two gain lines are obtained by two-wave mixing between a probe field and two individual pump fields. The angular frequencies of the pumps are symmetrically tuned from the frequency of the probe. The frequency difference between the pumps corresponds to the separation of the two gain lines; as it increases, the crystal gradually converts from normal dispersion without detuning to an anomalously dispersive medium. The time advance is measured as 0.28 sec for a pulse propagating through a medium with a 2Hz gain separation, compared to the same pulse propagating through empty space. We also demonstrate directly anomalous dispersion profile using a modfied experimental configuration. Finally, we discuss how anomalous dispersion produced this way in a faster photorefractive crystal (such as SPS: Sn2P2S6) could be employed to enhance the sensitivity-bandwidth product of a LIGO type gravitational wave detector augmented by a White Light Cavity.Comment: 14 pages, 5 figure

    Short-Term Generation Asset Valuation

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    We present a method for valuing a power plant over a short term period using Monte Carlo simulation. The power plant valuation problem is formulated as a multi stage stochastic problem. We assume there are hourly markets for both electricity and the fuel used by the generator, and their prices follow some Ito processes. At each hour, the power plant operator must decide to run or not to run the unit so as to maximize expected profit. A certain lead time for commitment decision is necessary to start up a unit. The commitment decision, once made, is subject to physical constraints such as minimum uptime and downtime constraints. The generator\u27\u27s startup cost, is also taken into account in our model. The Monte Carlo method is employed not only in forward moving simulation, but also backward moving recursion of dynamic programming. We demonstrate through numerical tests how the physical constraints affect a power plant value

    Further SEASAT SAR coastal ocean wave analysis

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    Analysis techniques used to exploit SEASAT synthetic aperture radar (SAR) data of gravity waves are discussed and the SEASAT SAR's ability to monitor large scale variations in gravity wave fields in both deep and shallow water is evaluated. The SAR analysis techniques investigated included motion compensation adjustments and the semicausal model for spectral analysis of SAR wave data. It was determined that spectra generated from fast Fourier transform analysis (FFT) of SAR wave data were not significantly altered when either range telerotation adjustments or azimuth focus shifts were used during processing of the SAR signal histories, indicating that SEASAT imagery of gravity waves is not significantly improved or degraded by motion compensation adjustments. Evaluation of the semicausal (SC) model using SEASAT SAR data from Rev. 974 indicates that the SC spectral estimates were not significantly better than the FFT results

    Functional modulation of the transient outward current Ito by KCNE beta-subunits and regional distribution in human non-failing and failing hearts

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    Objectives: The function of Kv4.3 (KCND3) channels, which underlie the transient outward current I,, in human heart, can be modulated by several accessory subunits such as KChIP2 and KCNE1-KCNE5. Here we aimed to determine the regional expression of Kv4.3, KChIP2, and KCNE mRNAs in non-failing and failing human hearts and to investigate the functional consequences of subunit coexpression in heterologous expression systems. Methods: We quantified mRNA levels for two Kv4.3 isoforms, Kv4.3-S and Kv4.3-L, and for KChIP2 as well as KCNE1-KCNE5 with real-time RT-PCR. We also studied the effects of KCNEs on Kv4.3 + KChIP2 current characteristics in CHO cells with the whole-cell voltage-clamp method. Results: In non-failing hearts, low expression was found for KCNE1, KCNE3, and KCNE5, three times higher expression for KCNE2, and 60 times higher for KCNE4. Transmural gradients were detected only for KChIP2 in left and right ventricles. Compared to non-failing tissue, failing hearts showed higher expression of Kv4.3-L and KCNE1 and lower of Kv4.3-S, KChIP2, KCNE4, and KCNE5. In CHO cells, Kv4.3 + KChIP2 currents were differentially modified by co-expressed KCNEs: time constants of inactivation were shorter with KCNE1 and KCNE3-5 while time-to-peak was decreased, and V-0.5 of steady-state inactivation was shifted to more negative potentials by all KCNE subunits. Importantly, KCNE2 induced a unique and prominent 'overshoot' of peak current during recovery from inactivation similar to that described for human I-to while other KCNE subunits induced little (KCNE4,5) or no overshoot. Conclusions: All KCNEs are expressed in the human heart at the transcript level. Compared to It. in native human myocytes, none of the combination of KChIP2 and KCNE produced an ideal congruency in current characteristics, suggesting that additional factors contribute to the regulation of the native I-to channel

    947-114 Effects of Azimilide (NE-10064) on Cardiac K Channels

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    To understand the cellular mechanism of action of azimilide (Aziml, a novel class III antiarrhythmic agent, we studied its effegts on K currents in guinea pig and canine ventricular myocytes: slow (lKs) and rapid (lKr) delayed rectifier, inward rectifier (lKI) and transient outward (Ito) currents. To facilitate the quantification and comparison of drug potencies, the recording conditions were designed to “isolate” these K currents from other ionic currents and from each other. In particular, since it is difficult to separate IKrand IKsunder normal physiological conditions, a Na- and Ca-free external solution was used to dissect the two. This was confirmed by the selective action of dofetilide. Azim blocked IKsconcentration dependently (0.2–10 μM) and reversibly. Block was potentiated by more positive VtAt±30 mV, 2 μM Azim blocked IKsby 58±13% (n=6). Azim caused a time-dependent reduction of IKsduring depolarization and slowed IKsdeactivation, suggesting that block and unblock occurred mainly in the open state. Azim also blocked IKrconcentration dependently (0.1–2 μM)and reversibly. At -20 mV, 1 μM Azim blocked IKrby 86±10% (n=3). On the other hand, Ito(IC50> 10 μM.n=6) and IKI(IC50> 50 μM.n=2) were much less sensitive to Azim than IKror IKSIn conclusion, blockade of both delayed rectifiers makes important contributions to the class III action of Azim
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