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Sample records for rapid delayed rectifier

  1. Effects of stress on the rapid component of delayed rectifier potassium current in rat cardiomyocytes

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    Jiang-li QI

    2017-10-01

    Full Text Available Objective To observe the effect of stress on the rapid component of delayed rectifier potassium current (IKr in rat cardiomyocytes. Methods Forty male SD rats were randomly divided into four groups (10 each: control group (Ctrl, exhaustive group (ES, noise group (WN and composite group (ES+WN. Stress animal models were prepared as follows: Rats in ES group were undergoing exhaustive swimming as the stress factor, in WN group undergoing white noise and in ES+WN group undergoing exhaustive swimming + white noise as the stress factor. Langendorff device was used to reversely perfuse collagenase for isolating the rat's ventricular myocytes. The effect of stress on IKr current and gating mechanism of single ventricular myocyte was recorded by whole-cell patch clamp technique. Results Compared with the Ctrl group, the tail current density of IKr (IKr,tail of ventricular myocytes increased significantly in ES group and WN group (P<0.01. The IKr,tail current density of the ventricular myocytes in ES+WN group was significantly higher than that in ES group and WN group (P<0.01, and the effect was voltage dependent. Gating mechanism revealed that the half inactivation voltage of IKr,tail (V1/2,inact can be shifted to the right in ES group, WN group and ES+WN group when compared with the Ctrl group, and the recovery time constant shortened after inactivation (P<0.01. However, the steady-state activation, fast inactivation constant and voltage dependence of IKr,tail were not statistically significant in ES group, WN group and ES+WN group when compared with the Ctrl group. Conclusion Stress increases the IKr current in rat cardiomyocytes, suggesting it be one of the electrophysiological bases of stress-induced arrhythmia. DOI: 10.11855/j.issn.0577-7402.2017.08.06

  2. Antiarrhythmic properties of a rapid delayed-rectifier current activator in rabbit models of acquired long QT syndrome

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    Diness, Thomas G; Yeh, Yung-Hsin; Qi, Xiao Yan

    2008-01-01

    effect of a novel compound (NS1643) that activates the rapid delayed-rectifier K+ current, I(Kr), in two rabbit models of acquired LQTS. METHODS AND RESULTS: We used two clinically relevant in vivo rabbit models of TdP in which we infused NS1643 or vehicle: (i) three-week atrioventricular block...... with ventricular bradypacing; (ii) dofetilide-induced I(Kr) inhibition in methoxamine-sensitized rabbits. In addition, we studied effects on ionic currents in cardiomyocytes with I(Kr) suppressed by bradycardia remodelling or dofetilide exposure. Bradypaced rabbits developed QT interval prolongation, spontaneous...... ventricular ectopy, and TdP. Infusion of NS1643 completely suppressed arrhythmic activity and shortened the QT interval; vehicle had no effect. NS1643 also suppressed ventricular tachyarrhythmias caused by infusion of dofetilide to methoxamine-sensitized rabbits, and reversed dofetilide-induced QT...

  3. Interaction between the Cardiac Rapidly (IKr) and Slowly (IKs) Activating Delayed Rectifier Potassium Channels Revealed by Low K+-induced hERG Endocytic Degradation*

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    Guo, Jun; Wang, Tingzhong; Yang, Tonghua; Xu, Jianmin; Li, Wentao; Fridman, Michael D.; Fisher, John T.; Zhang, Shetuan

    2011-01-01

    Cardiac repolarization is controlled by the rapidly (IKr) and slowly (IKs) activating delayed rectifier potassium channels. The human ether-a-go-go-related gene (hERG) encodes IKr, whereas KCNQ1 and KCNE1 together encode IKs. Decreases in IKr or IKs cause long QT syndrome (LQTS), a cardiac disorder with a high risk of sudden death. A reduction in extracellular K+ concentration ([K+]o) induces LQTS and selectively causes endocytic degradation of mature hERG channels from the plasma membrane. In the present study, we investigated whether IKs compensates for the reduced IKr under low K+ conditions. Our data show that when hERG and KCNQ1 were expressed separately in human embryonic kidney (HEK) cells, exposure to 0 mm K+ for 6 h completely eliminated the mature hERG channel expression but had no effect on KCNQ1. When hERG and KCNQ1 were co-expressed, KCNQ1 significantly delayed 0 mm K+-induced hERG reduction. Also, hERG degradation led to a significant reduction in KCNQ1 in 0 mm K+ conditions. An interaction between hERG and KCNQ1 was identified in hERG+KCNQ1-expressing HEK cells. Furthermore, KCNQ1 preferentially co-immunoprecipitated with mature hERG channels that are localized in the plasma membrane. Biophysical and pharmacological analyses indicate that although hERG and KCNQ1 closely interact with each other, they form distinct hERG and KCNQ1 channels. These data extend our understanding of delayed rectifier potassium channel trafficking and regulation, as well as the pathology of LQTS. PMID:21844197

  4. Functional Cross-Talk between the α1- and β1-Adrenergic Receptors Modulates the Rapidly Activating Delayed Rectifier Potassium Current in Guinea Pig Ventricular Myocytes

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    Di Xu

    2014-08-01

    Full Text Available The rapidly activating delayed rectifier potassium current (IKr plays a critical role in cardiac repolarization. Although IKr is known to be regulated by both α1- and β1-adrenergic receptors (ARs, the cross-talk and feedback mechanisms that dictate its response to α1- and β1-AR activation are not known. In the present study, IKr was recorded using the whole-cell patch-clamp technique. IKr amplitude was measured before and after the sequential application of selective adrenergic agonists targeting α1- and β1-ARs. Stimulation of either receptor alone (α1-ARs using 1 μM phenylephrine (PE or β1-ARs using 10 μM xamoterol (Xamo reduced IKr by 0.22 ± 0.03 and 0.28 ± 0.01, respectively. The voltage-dependent activation curve of IKr shifted in the negative direction. The half-maximal activation voltage (V0.5 was altered by −6.35 ± 1.53 and −1.95 ± 2.22 mV, respectively, with no major change in the slope factor (k. When myocytes were pretreated with Xamo, PE-induced reduction in IKr was markedly blunted and the corresponding change in V0.5 was significantly altered. Similarly, when cells were pretreated with PE, Xamo-induced reduction of IKr was significantly attenuated. The present results demonstrate that functional cross-talk between α1- and β1-AR signaling regulates IKr. Such non-linear regulation may form a protective mechanism under excessive adrenergic stimulation.

  5. Differential roles of two delayed rectifier potassium currents in regulation of ventricular action potential duration and arrhythmia susceptibility.

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    Devenyi, Ryan A; Ortega, Francis A; Groenendaal, Willemijn; Krogh-Madsen, Trine; Christini, David J; Sobie, Eric A

    2017-04-01

    Arrhythmias result from disruptions to cardiac electrical activity, although the factors that control cellular action potentials are incompletely understood. We combined mathematical modelling with experiments in heart cells from guinea pigs to determine how cellular electrical activity is regulated. A mismatch between modelling predictions and the experimental results allowed us to construct an improved, more predictive mathematical model. The balance between two particular potassium currents dictates how heart cells respond to perturbations and their susceptibility to arrhythmias. Imbalances of ionic currents can destabilize the cardiac action potential and potentially trigger lethal cardiac arrhythmias. In the present study, we combined mathematical modelling with information-rich dynamic clamp experiments to determine the regulation of action potential morphology in guinea pig ventricular myocytes. Parameter sensitivity analysis was used to predict how changes in ionic currents alter action potential duration, and these were tested experimentally using dynamic clamp, a technique that allows for multiple perturbations to be tested in each cell. Surprisingly, we found that a leading mathematical model, developed with traditional approaches, systematically underestimated experimental responses to dynamic clamp perturbations. We then re-parameterized the model using a genetic algorithm, which allowed us to estimate ionic current levels in each of the cells studied. This unbiased model adjustment consistently predicted an increase in the rapid delayed rectifier K + current and a drastic decrease in the slow delayed rectifier K + current, and this prediction was validated experimentally. Subsequent simulations with the adjusted model generated the clinically relevant prediction that the slow delayed rectifier is better able to stabilize the action potential and suppress pro-arrhythmic events than the rapid delayed rectifier. In summary, iterative coupling of

  6. A low cost rapid prototype platform for a three phase PFC rectifier application

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    Haase, Frerk; Kouchaki, Alireza; Nymand, Morten

    2015-01-01

    In this paper the design and development of a low cost rapid prototype platform for a Three Phase PFC rectifier application is presented. The active rectifier consists of a SiC-MOSFET based PWM converter and a low cost rapid prototype platform for simulating and implementing the digital control...... is then performed using automatic code generation for embedded targets, which provided a close link between simulation and implementation of the PFC controller. The paper shows how this rapid prototype platform developed and how it was used for the design and implementation of the controller for a high efficient Si...

  7. Photoperiod Modulates Fast Delayed Rectifier Potassium Currents in the Mammalian Circadian Clock

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    Sahar Farajnia

    2016-09-01

    Full Text Available One feature of the mammalian circadian clock, situated in the suprachiasmatic nucleus (SCN, is its ability to measure day length and thereby contribute to the seasonal adaptation of physiology and behavior. The timing signal from the SCN, namely the 24 hr pattern of electrical activity, is adjusted according to the photoperiod being broader in long days and narrower in short days. Vasoactive intestinal peptide and gamma-aminobutyric acid play a crucial role in intercellular communication within the SCN and contribute to the seasonal changes in phase distribution. However, little is known about the underlying ionic mechanisms of synchronization. The present study was aimed to identify cellular mechanisms involved in seasonal encoding by the SCN. Mice were adapted to long-day (light–dark 16:8 and short-day (light–dark 8:16 photoperiods and membrane properties as well as K+ currents activity of SCN neurons were measured using patch-clamp recordings in acute slices. Remarkably, we found evidence for a photoperiodic effect on the fast delayed rectifier K+ current, that is, the circadian modulation of this ion channel’s activation reversed in long days resulting in 50% higher peak values during the night compared with the unaltered day values. Consistent with fast delayed rectifier enhancement, duration of action potentials during the night was shortened and afterhyperpolarization potentials increased in amplitude and duration. The slow delayed rectifier, transient K+ currents, and membrane excitability were not affected by photoperiod. We conclude that photoperiod can change intrinsic ion channel properties of the SCN neurons, which may influence cellular communication and contribute to photoperiodic phase adjustment.

  8. Inhibitory Effects of Glycyrrhetinic Acid on the Delayed Rectifier Potassium Current in Guinea Pig Ventricular Myocytes and HERG Channel

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    Delin Wu

    2013-01-01

    Full Text Available Background. Licorice has long been used to treat many ailments including cardiovascular disorders in China. Recent studies have shown that the cardiac actions of licorice can be attributed to its active component, glycyrrhetinic acid (GA. However, the mechanism of action remains poorly understood. Aim. The effects of GA on the delayed rectifier potassium current (IK, the rapidly activating (IKr and slowly activating (IKs components of IK, and the HERG K+ channel expressed in HEK-293 cells were investigated. Materials and Methods. Single ventricular myocytes were isolated from guinea pig myocardium using enzymolysis. The wild type HERG gene was stably expressed in HEK293 cells. Whole-cell patch clamping was used to record IK (IKr, IKs and the HERG K+ current. Results. GA (1, 5, and 10 μM inhibited IK (IKr, IKs and the HERG K+ current in a concentration-dependent manner. Conclusion. GA significantly inhibited the potassium currents in a dose- and voltage-dependent manner, suggesting that it exerts its antiarrhythmic action through the prolongation of APD and ERP owing to the inhibition of IK (IKr, IKs and HERG K+ channel.

  9. Subcellular localization of the delayed rectifier K(+) channels KCNQ1 and ERG1 in the rat heart

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    Rasmussen, Hanne Borger; Møller, Morten; Knaus, Hans-Günther

    2003-01-01

    In the heart, several K(+) channels are responsible for the repolarization of the cardiac action potential, including transient outward and delayed rectifier K(+) currents. In the present study, the cellular and subcellular localization of the two delayed rectifier K(+) channels, KCNQ1 and ether......-a-go-go-related gene-1 (ERG1), was investigated in the adult rat heart. Confocal immunofluorescence microscopy of atrial and ventricular cells revealed that whereas KCNQ1 labeling was detected in both the peripheral sarcolemma and a structure transversing the myocytes, ERG1 immunoreactivity was confined to the latter....... Immunoelectron microscopy of atrial and ventricular myocytes showed that the ERG1 channel was primarily expressed in the transverse tubular system and its entrance, whereas KCNQ1 was detected in both the peripheral sarcolemma and in the T tubules. Thus, whereas ERG1 displays a very restricted subcellular...

  10. Rapid activation of inwardly rectifying potassium channels by immobile G-protein-coupled receptors.

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    Lober, Robert M; Pereira, Miguel A; Lambert, Nevin A

    2006-11-29

    G-protein-coupled receptors (GPCRs) mediate slow synaptic transmission and many other effects of small molecule and peptide neurotransmitters. In the standard model of GPCR signaling, receptors and G-proteins diffuse laterally within the plane of the plasma membrane and encounter each other by random collision. This model predicts that signaling will be most efficient if both GPCRs and G-proteins are free to diffuse, thus maximizing collision frequency. However, neuronal GPCRs are often recruited to and enriched at specific synaptic locations, suggesting receptor mobility is restricted in these cells. Here, we test the hypothesis that restricting GPCR mobility impairs signaling in neurons by limiting the frequency of collisions between receptors and G-proteins. Mu-opioid receptors (MORs) were immobilized on the surface of cerebellar granule neurons by avidin-mediated cross-linking, and inwardly rectifying potassium (GIRK) channels were used as rapid indicators of G-protein activation. Mobile and immobile MORs activated GIRK channels with the same onset kinetics and agonist sensitivity in these neurons. In a heterologous expression system, GFP (green fluorescent protein)-tagged G alpha(oA) subunits remained mobile after cross-linking, but their mobility was reduced in the presence of immobile MORs, suggesting that these receptors and subunits were transiently precoupled. In addition, channel activation could be reconstituted with immobile GPCRs, G-protein heterotrimers, and GIRK channels. These results show that collision frequency is not rate-limiting for G-protein activation in CNS neurons, and are consistent with the idea that signaling components are compartmentalized or preassembled.

  11. High-fat diet-dependent modulation of the delayed rectifier K(+) current in adult guinea pig atrial myocytes.

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    Aromolaran, Ademuyiwa S; Colecraft, Henry M; Boutjdir, Mohamed

    2016-06-03

    Obesity is associated with hyperlipidemia, electrical remodeling of the heart, and increased risk of supraventricular arrhythmias in both male and female patients. The delayed rectifier K(+) current (IK), is an important regulator of atrial repolarization. There is a paucity of studies on the functional role of IK in response to obesity. Here, we assessed the obesity-mediated functional modulation of IK in low-fat diet (LFD), and high-fat diet (HFD) fed adult guinea pigs. Guinea pigs were randomly divided into control and obese groups fed, ad libitum, with a LFD (10 kcal% fat) or a HFD (45 kcal% fat) respectively. Action potential duration (APD), and IK were studied in atrial myocytes and IKr and IKs in HEK293 cells using whole-cell patch clamp electrophysiology. HFD guinea pigs displayed a significant increase in body weight, total cholesterol and total triglycerides within 50 days. Atrial APD at 30% (APD30) and 90% (APD90) repolarization were shorter, while atrial IK density was significantly increased in HFD guinea pigs. Exposure to palmitic acid (PA) increased heterologously expressed IKr and IKs densities, while oleic acid (OA), severely reduced IKr and had no effect on IKs. The data are first to show that in obese guinea pigs abbreviated APD is due to increased IK density likely through elevations of PA. Our findings may have crucial implications for targeted treatment options for obesity-related arrhythmias. Published by Elsevier Inc.

  12. The role of ERK-1/2 in the N/OFQ-induced inhibition of delayed rectifier potassium currents

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    Wang, Wei [Laboratory of Neural Electrophysiology, Department of Physiology, Harbin Medical University, Harbin 150081 (China); Cui, Qingbo [Department of Pediatric Surgery, The 2nd Hospital of Harbin Medical University, Harbin 150081 (China); Li, Yurong [Laboratory of Neural Electrophysiology, Department of Physiology, Harbin Medical University, Harbin 150081 (China); Li, Baoxin [Institute of Pharmacology, Harbin Medical University, Harbin 150081 (China); Yang, Xu; Cui, Lanwei; Jin, Hongbo [Laboratory of Neural Electrophysiology, Department of Physiology, Harbin Medical University, Harbin 150081 (China); Qu, Lihui, E-mail: lihui_qu@yahoo.com.cn [Laboratory of Neural Electrophysiology, Department of Physiology, Harbin Medical University, Harbin 150081 (China)

    2010-04-16

    Nociceptin/orphanin FQ (N/OFQ) is an endogenous opioid-like heptadecapeptide involved in many neurocognitive functions, including learning and memory. Our previous report showed that N/OFQ inhibits the delayed rectifier potassium current (I{sub K}), and this effect is associated with protein kinase C (PKC) activation. Therefore, we wanted to determine if extracellular signal-regulated kinase-1/2 (ERK-1/2) signaling is regulated by N/OFQ and associated with the effect of N/OFQ on the I{sub K}. In the current study, we tested if N/OFQ and two PKC activators [phorbol 12,13-dibutyrate (PDBu) and ingenol 3,20-dibenzoate (IDB)] affected the phosphorylation level of ERK-1/2 and its nuclear substrate, ETS-like transcription factor-1 (Elk-1), using western blots. In addition, we tested if ERK-1/2 affected the N/OFQ-induced inhibition of the I{sub K} by using whole-cell patch-clamp recordings in acutely dissociated rat parietal cortical neurons. We found that N/OFQ, PDBu, and IDB increased the amount of phosphorylated ERK-1/2 and Elk-1; U0126, a specific inhibitor for ERK-1/2, attenuated the inhibitory effect of N/OFQ on the I{sub K}. These data suggest that the ERK-1/2 pathway, at least in part, mediates the inhibitory effect of N/OFQ on the I{sub K} in acutely dissociated rat cerebral parietal cortical neurons.

  13. Forskolin suppresses delayed-rectifier K+ currents and enhances spike frequency-dependent adaptation of sympathetic neurons.

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    Luis I Angel-Chavez

    Full Text Available In signal transduction research natural or synthetic molecules are commonly used to target a great variety of signaling proteins. For instance, forskolin, a diterpene activator of adenylate cyclase, has been widely used in cellular preparations to increase the intracellular cAMP level. However, it has been shown that forskolin directly inhibits some cloned K+ channels, which in excitable cells set up the resting membrane potential, the shape of action potential and regulate repetitive firing. Despite the growing evidence indicating that K+ channels are blocked by forskolin, there are no studies yet assessing the impact of this mechanism of action on neuron excitability and firing patterns. In sympathetic neurons, we find that forskolin and its derivative 1,9-Dideoxyforskolin, reversibly suppress the delayed rectifier K+ current (IKV. Besides, forskolin reduced the spike afterhyperpolarization and enhanced the spike frequency-dependent adaptation. Given that IKV is mostly generated by Kv2.1 channels, HEK-293 cells were transfected with cDNA encoding for the Kv2.1 α subunit, to characterize the mechanism of forskolin action. Both drugs reversible suppressed the Kv2.1-mediated K+ currents. Forskolin inhibited Kv2.1 currents and IKV with an IC50 of ~32 μM and ~24 µM, respectively. Besides, the drug induced an apparent current inactivation and slowed-down current deactivation. We suggest that forskolin reduces the excitability of sympathetic neurons by enhancing the spike frequency-dependent adaptation, partially through a direct block of their native Kv2.1 channels.

  14. BACE1 modulates gating of KCNQ1 (Kv7.1) and cardiac delayed rectifier KCNQ1/KCNE1 (IKs).

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    Agsten, Marianne; Hessler, Sabine; Lehnert, Sandra; Volk, Tilmann; Rittger, Andrea; Hartmann, Stephanie; Raab, Christian; Kim, Doo Yeon; Groemer, Teja W; Schwake, Michael; Alzheimer, Christian; Huth, Tobias

    2015-12-01

    KCNQ1 (Kv7.1) proteins form a homotetrameric channel, which produces a voltage-dependent K(+) current. Co-assembly of KCNQ1 with the auxiliary β-subunit KCNE1 strongly up-regulates this current. In cardiac myocytes, KCNQ1/E1 complexes are thought to give rise to the delayed rectifier current IKs, which contributes to cardiac action potential repolarization. We report here that the type I membrane protein BACE1 (β-site APP-cleaving enzyme 1), which is best known for its detrimental role in Alzheimer's disease, but is also, as reported here, present in cardiac myocytes, serves as a novel interaction partner of KCNQ1. Using HEK293T cells as heterologous expression system to study the electrophysiological effects of BACE1 and KCNE1 on KCNQ1 in different combinations, our main findings were the following: (1) BACE1 slowed the inactivation of KCNQ1 current producing an increased initial response to depolarizing voltage steps. (2) Activation kinetics of KCNQ1/E1 currents were significantly slowed in the presence of co-expressed BACE1. (3) BACE1 impaired reconstituted cardiac IKs when cardiac action potentials were used as voltage commands, but interestingly augmented the IKs of ATP-deprived cells, suggesting that the effect of BACE1 depends on the metabolic state of the cell. (4) The electrophysiological effects of BACE1 on KCNQ1 reported here were independent of its enzymatic activity, as they were preserved when the proteolytically inactive variant BACE1 D289N was co-transfected in lieu of BACE1 or when BACE1-expressing cells were treated with the BACE1-inhibiting compound C3. (5) Co-immunoprecipitation and fluorescence recovery after photobleaching (FRAP) supported our hypothesis that BACE1 modifies the biophysical properties of IKs by physically interacting with KCNQ1 in a β-subunit-like fashion. Strongly underscoring the functional significance of this interaction, we detected BACE1 in human iPSC-derived cardiomyocytes and murine cardiac tissue and observed

  15. Evidence for Inhibitory Effects of Flupirtine, a Centrally Acting Analgesic, on Delayed Rectifier K+ Currents in Motor Neuron-Like Cells

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    Sheng-Nan Wu

    2012-01-01

    Full Text Available Flupirtine (Flu, a triaminopyridine derivative, is a centrally acting, non-opiate analgesic agent. In this study, effects of Flu on K+ currents were explored in two types of motor neuron-like cells. Cell exposure to Flu decreased the amplitude of delayed rectifier K+ current (IK(DR with a concomitant raise in current inactivation in NSC-34 neuronal cells. The dissociation constant for Flu-mediated increase of IK(DR inactivation rate was about 9.8 μM. Neither linopirdine (10 μM, NMDA (30 μM, nor gabazine (10 μM reversed Flu-induced changes in IK(DR inactivation. Addition of Flu shifted the inactivation curve of IK(DR to a hyperpolarized potential. Cumulative inactivation for IK(DR was elevated in the presence of this compound. Flu increased the amplitude of M-type K+ current (IK(M and produced a leftward shift in the activation curve of IK(M. In another neuronal cells (NG108-15, Flu reduced IK(DR amplitude and enhanced the inactivation rate of IK(DR. The results suggest that Flu acts as an open-channel blocker of delayed-rectifier K+ channels in motor neurons. Flu-induced block of IK(DR is unlinked to binding to NMDA or GABA receptors and the effects of this agent on K+ channels are not limited to its action on M-type K+ channels.

  16. EMC Increasing of PWM Rectifier in Comparison with Classical Rectifier

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    R. Dolecek

    2008-12-01

    Full Text Available Pulse width modulated rectifier is a very popular topic nowadays. The modern industrial production demands continuous and lossless conversion of electrical energy parameters. This need leads to wide spread of power semiconductor converters. The rapid development in power electronics and microprocessor technology enables to apply sophisticated control methods that eliminate negative side effects of the power converters on the supply network. The phase controlled thyristor rectifiers overload the supply network with higher harmonics and reactive power consumption. That is why the PWM rectifier is being examined. In comparison with the phase controlled rectifier it can be controlled to consume nearly sinusoidal current with power factor equal to unity. Another advantage is its capability of energy recuperation. The PWM rectifier can assert itself for its good behavior in many applications, for example as an input rectifier in indirect frequency converter, or in traction. Traction vehicles equipped with PWM rectifier do not consume reactive power, do not load the supply network with higher harmonics, and the recuperation is possible. The paper deals with the PWM rectifier functional model realization and examination. Electromagnetic compatibility of PWM rectifier and classical phase controlled rectifier is compared on the basis of the input current harmonic analysis.

  17. Effects of itopride hydrochloride on the delayed rectifier K+ and L-type CA2+ currents in guinea-pig ventricular myocytes.

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    Morisawa, T; Hasegawa, J; Hama, R; Kitano, M; Kishimoto, Y; Kawasaki, H

    1999-01-01

    The effects of itopride hydrochloride, a new drug used to regulate motility in the gastrointestinal tract, on the delayed rectifier K+ current (I(K)) and the L-type Ca2+ current (I(Ca)) were evaluated in guinea-pig ventricular myocytes at concentrations of 1, 10 and 100 microM to determine whether the drug has a proarrhythmic effect through blockade of I(K). Itopride did not affect I(K) at concentrations of 100 microM or less, and no significant effects of 1, 10 or 100 microM itopride were observed on the inward rectifier K+ current (I(K1)) responsible for the resting potential and final repolarization phase of the action potential. We next investigated the effects of itopride on L-type Ca2+ current (I(Ca)). Significant inhibition of I(Ca) was observed at itopride concentrations greater than 10 microM. These results suggested that itopride hydrochloride has an inhibitory effect on I(Ca) at concentrations much higher than those in clinical use.

  18. Delayed Maturation of Fast-Spiking Interneurons Is Rectified by Activation of the TrkB Receptor in the Mouse Model of Fragile X Syndrome.

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    Nomura, Toshihiro; Musial, Timothy F; Marshall, John J; Zhu, Yiwen; Remmers, Christine L; Xu, Jian; Nicholson, Daniel A; Contractor, Anis

    2017-11-22

    Fragile X syndrome (FXS) is a neurodevelopmental disorder that is a leading cause of inherited intellectual disability, and the most common known cause of autism spectrum disorder. FXS is broadly characterized by sensory hypersensitivity and several developmental alterations in synaptic and circuit function have been uncovered in the sensory cortex of the mouse model of FXS ( Fmr1 KO). GABA-mediated neurotransmission and fast-spiking (FS) GABAergic interneurons are central to cortical circuit development in the neonate. Here we demonstrate that there is a delay in the maturation of the intrinsic properties of FS interneurons in the sensory cortex, and a deficit in the formation of excitatory synaptic inputs on to these neurons in neonatal Fmr1 KO mice. Both these delays in neuronal and synaptic maturation were rectified by chronic administration of a TrkB receptor agonist. These results demonstrate that the maturation of the GABAergic circuit in the sensory cortex is altered during a critical developmental period due in part to a perturbation in BDNF-TrkB signaling, and could contribute to the alterations in cortical development underlying the sensory pathophysiology of FXS. SIGNIFICANCE STATEMENT Fragile X (FXS) individuals have a range of sensory related phenotypes, and there is growing evidence of alterations in neuronal circuits in the sensory cortex of the mouse model of FXS ( Fmr1 KO). GABAergic interneurons are central to the correct formation of circuits during cortical critical periods. Here we demonstrate a delay in the maturation of the properties and synaptic connectivity of interneurons in Fmr1 KO mice during a critical period of cortical development. The delays both in cellular and synaptic maturation were rectified by administration of a TrkB receptor agonist, suggesting reduced BDNF-TrkB signaling as a contributing factor. These results provide evidence that the function of fast-spiking interneurons is disrupted due to a deficiency in neurotrophin

  19. Correlation analysis between the delayed rectifier potassium channel KCNE1 (G38S) polymorphism and atrial fibrillation among the senior Uygur population in Xinjiang.

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    Wugeti, N; Yu-Jun, G; Juan, S; Mahemuti, A

    2015-12-07

    Current resources to support genetic screening among the Uygur population in Xinjiang territory for atrial fibrillation (AF) have not been well established and large-scale epidemiological analyses are needed. Using patients from the Xinjiang Uygur population as subjects, and the delayed rectifier potassium channel KCNE1 and its associated polymorphism G38S (rs1805127) as the candidate gene, we analyzed the correlation between the G38S polymorphism and AF among the senior Uygur population in Xinjiang Province. Peripheral blood from AF Uygur patients (patient group) or non-AF Uygur patients (control group) from Xinjiang territory was collected (70 patients each). DNA was purified and tested by polymerase chain reaction-restriction fragment length polymorphism for the genotype and allelic distribution of KCNE1 (G38S). Correlation analysis between AF and multiple health-related factors was performed by logistic regression. Among patients with the KCNE1 G38S polymorphism, the genotypes AA, AG, and GG were present at frequencies of 17.14, 27.14, and 55.71%, respectively, in the patient group, compared with 24.29, 50, and 25.71%, respectively, in the control group. The difference between these two groups was shown to be statistically significant (P Logistic regression showed that the GG genotype is correlated with the incidence of AF in Uygur seniors (P < 0.05). The incidence of AF among the senior Uygur population in Xinjiang territory was correlated with the KCNE1 (G38S) polymorphism, which may be an independent risk factor for Uygur AF patients.

  20. [Ca2+]i Elevation and Oxidative Stress Induce KCNQ1 Protein Translocation from the Cytosol to the Cell Surface and Increase Slow Delayed Rectifier (IKs) in Cardiac Myocytes*

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    Wang, Yuhong; Zankov, Dimitar P.; Jiang, Min; Zhang, Mei; Henderson, Scott C.; Tseng, Gea-Ny

    2013-01-01

    Our goals are to simultaneously determine the three-dimensional distribution patterns of KCNQ1 and KCNE1 in cardiac myocytes and to study the mechanism and functional implications for variations in KCNQ1/KCNE1 colocalization in myocytes. We monitored the distribution patterns of KCNQ1, KCNE1, and markers for subcellular compartments/organelles using immunofluorescence/confocal microscopy and confirmed the findings in ventricular myocytes by directly observing fluorescently tagged KCNQ1-GFP and KCNE1-dsRed expressed in these cells. We also monitored the effects of stress on KCNQ1-GFP and endoplasmic reticulum (ER) remodeling during live cell imaging. The data showed that 1) KCNE1 maintained a stable cell surface localization, whereas KCNQ1 exhibited variations in the cytosolic compartment (striations versus vesicles) and the degree of presence on the cell surface; 2) the degree of cell surface KCNQ1/KCNE1 colocalization was positively correlated with slow delayed rectifier (IKs) current density; 3) KCNQ1 and calnexin (an ER marker) shared a cytosolic compartment; and 4) in response to stress ([Ca2+]i elevation, oxidative overload, or AT1R stimulation), KCNQ1 exited the cytosolic compartment and trafficked to the cell periphery in vesicles. This was accompanied by partial ER fragmentation. We conclude that the cellular milieu regulates KCNQ1 distribution in cardiac myocytes and that stressful conditions can increase IKs by inducing KCNQ1 movement to the cell surface. This represents a hitherto unrecognized mechanism by which IKs fulfills its function as a repolarization reserve in ventricular myocytes. PMID:24142691

  1. [Ca2+]i elevation and oxidative stress induce KCNQ1 protein translocation from the cytosol to the cell surface and increase slow delayed rectifier (IKs) in cardiac myocytes.

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    Wang, Yuhong; Zankov, Dimitar P; Jiang, Min; Zhang, Mei; Henderson, Scott C; Tseng, Gea-Ny

    2013-12-06

    Our goals are to simultaneously determine the three-dimensional distribution patterns of KCNQ1 and KCNE1 in cardiac myocytes and to study the mechanism and functional implications for variations in KCNQ1/KCNE1 colocalization in myocytes. We monitored the distribution patterns of KCNQ1, KCNE1, and markers for subcellular compartments/organelles using immunofluorescence/confocal microscopy and confirmed the findings in ventricular myocytes by directly observing fluorescently tagged KCNQ1-GFP and KCNE1-dsRed expressed in these cells. We also monitored the effects of stress on KCNQ1-GFP and endoplasmic reticulum (ER) remodeling during live cell imaging. The data showed that 1) KCNE1 maintained a stable cell surface localization, whereas KCNQ1 exhibited variations in the cytosolic compartment (striations versus vesicles) and the degree of presence on the cell surface; 2) the degree of cell surface KCNQ1/KCNE1 colocalization was positively correlated with slow delayed rectifier (IKs) current density; 3) KCNQ1 and calnexin (an ER marker) shared a cytosolic compartment; and 4) in response to stress ([Ca(2+)]i elevation, oxidative overload, or AT1R stimulation), KCNQ1 exited the cytosolic compartment and trafficked to the cell periphery in vesicles. This was accompanied by partial ER fragmentation. We conclude that the cellular milieu regulates KCNQ1 distribution in cardiac myocytes and that stressful conditions can increase IKs by inducing KCNQ1 movement to the cell surface. This represents a hitherto unrecognized mechanism by which IKs fulfills its function as a repolarization reserve in ventricular myocytes.

  2. Pharmacological activation of rapid delayed rectifier potassium current suppresses bradycardia-induced triggered activity in the isolated guinea pig heart

    DEFF Research Database (Denmark)

    Hansen, Rie Schultz; Olesen, Søren-Peter; Grunnet, Morten

    2007-01-01

    arrhythmias. We present here data that support that NS3623 affects native I(Kr) and report the effects that activating this potassium current have in the intact guinea pig heart. In Langendorff-perfused hearts, the compound showed a concentration-dependent shortening of action potential duration, which...... was also detected as concentration-dependent shorter QT intervals. There was no sign of action potential triangulation or reverse use dependence. NS3623 decreased QT variability and distinctly decreased the occurrence of extrasystoles in the acutely bradypaced hearts. Taken together, the present data...

  3. SPS rectifier stations

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    The first of the twelves SPS rectifier stations for the bending magnets arrived at CERN at the end of the year. The photograph shows a station with the rectifiers on the left and in the other three cubicles the chokes, capacitors and resistor of the passive filter.

  4. Applying the Averaging Principle to a Logistic Equation with Rapidly Oscillating Delay

    Directory of Open Access Journals (Sweden)

    N. D. Bykova

    2014-01-01

    Full Text Available The problem about the local dynamics of the logistic equation with rapidly oscillating time-periodic piecewise constant coefficient of delay was considered. It was shown that the averaged equation is a logistic equation with two delays. The criterion of equilibrium point stability was obtained. Dynamical properties of the original equation was considered provided that the critical case of equilibrium point stability problem was implemented. It was found that an increase of delay coefficient oscillation frequency may lead to an unlimited process of “birth” and “death” steady mode.

  5. Rapid and durable response to intravenous immunoglobulin in delayed heparin-induced thrombocytopenia: a case report.

    Science.gov (United States)

    Lei, Brandon Z; Shatzel, Joseph J; Sendowski, Merav

    2017-04-01

    Heparin-induced thrombocytopenia (HIT) results in platelet consumption and a virulent thrombotic state, which generally responds to cessation of heparin and initiation of anticoagulation. Rarely, delayed HIT can occur and/or persist after heparin is discontinued. A 47-year-old male developed delayed HIT with severe thrombocytopenia and thrombosis after cardiac surgery. Thrombocytopenia developed and persisted after heparin cessation and did not improve despite sequential use of argatroban followed by bivalirudin. Treatment with intravenous immunoglobulin (IVIg) was well tolerated and resulted in rapid resolution of thrombocytopenia. There are few case reports on the management of delayed HIT with severe and prolonged thrombocytopenia. The risk for thrombosis and bleeding in the setting of an undefined time course increases uncertainty in management. This case, along with others accumulating in the literature, suggest that IVIg may be effective in treating delayed HIT with persistent thrombocytopenia. © 2016 AABB.

  6. Topology optimization of viscoelastic rectifiers

    DEFF Research Database (Denmark)

    Jensen, Kristian Ejlebjærg; Szabo, Peter; Okkels, Fridolin

    2012-01-01

    An approach for the design of microfluidic viscoelastic rectifiers is presented based on a combination of a viscoelastic model and the method of topology optimization. This presumption free approach yields a material layout topologically different from experimentally realized rectifiers...

  7. Use of rapid needs assessment as a tool to identify vaccination delays in Guatemala and Peru.

    Science.gov (United States)

    D'Ardenne, Katie K; Darrow, Juliana; Furniss, Anna; Chavez, Catia; Hernandez, Herminio; Berman, Stephen; Asturias, Edwin J

    2016-03-29

    To explore the use of rapid needs assessment (RNA) surveys to determine the prevalence and factors contributing to delays in vaccination of children in two low middle-income countries (LMIC). Data from two RNA surveys performed as part of program improvement evaluations in Guatemala and Peru were used for this analysis. The primary endpoint was the timeliness of immunization with delay defined as administration of vaccines beyond 28 days from recommended age for DTwP-HepB-Hib (Penta) and measles-mumps-rubella (MMR) vaccines, as well as past age-restrictions for rotavirus vaccine. Independent risk factors analyzed included child's gender, birth year, number of children in household, maternal age, maternal education, and food insecurity. Vaccine information was available from 811 children from 838 households surveyed. High rate of immunization delays was observed, with 75.6% of children in Guatemala and 57.8% of children in Peru being delayed for the third dose of Penta primary series. Factors associated with delayed vaccination in Guatemala included advanced maternal age and increased number of children in household. In Peru, significant associations were birth year before 2009, lower maternal education level, and increased number of children in household. RNA is a fast and effective method to identify timely vaccine coverage and derive a hypothesis of factors possibly associated with vaccination delay. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Restoration of uridine 5′-triphosphate-suppressed delayed rectifying K+ currents by an NO activator KMUP-1 involves RhoA/Rho kinase signaling in pulmonary artery smooth muscle cells

    Directory of Open Access Journals (Sweden)

    Zen-Kong Dai

    2016-12-01

    Full Text Available We have demonstrated that KMUP-1 (7-[2-[4-(2-chlorobenzenepiperazinyl]ethyl]-1,3-dimethylxanthine blunts monocrotaline-induced pulmonary arterial hypertension by altering Ca2+ sensitivity, K+-channel function, endothelial nitric oxide synthase activity, and RhoA/Rho kinase (ROCK expression. This study further investigated whether KMUP-1 impedes uridine 5′-triphosphate (UTP-inhibited delayed rectifying K+ (KDR current in rat pulmonary arteries involved the RhoA/ROCK signaling. Pulmonary artery smooth muscle cells (PASMCs were enzymatically dissociated from rat pulmonary arteries. KMUP-1 (30μM attenuated UTP (30μM-mediated membrane depolarization and abolished UTP-enhanced cytosolic Ca2+ concentration. Whole-cell patch-clamp electrophysiology was used to monitor KDR currents. A voltage-dependent KDR current was isolated and shown to consist of a 4-aminopyridine (5mM-sensitive component and an insensitive component. The 4-aminopyridine sensitive KDR current was suppressed by UTP (30μM. The ROCK inhibitor Y27632 (30μM abolished the ability of UTP to inhibit the KDR current. Like Y27632, KMUP-1 (30μM similarly abolished UTP-inhibited KDR currents. Superfused protein kinase A and protein kinase G inhibitors (KT5720, 300nM and KT5823, 300nM did not affect UTP-inhibited KDR currents, but the currents were restored by adding KMUP-1 (30μM to the superfusate. KMUP-1 reversal of KDR current inhibition by UTP predominantly involves the ROCK inhibition. The results indicate that the RhoA/ROCK signaling pathway plays a key role in eliciting PASMCs depolarization caused by UTP, which would result in pulmonary artery constriction. KMUP-1 blocks UTP-mediated PASMCs depolarization, suggesting that it would prevent abnormal pulmonary vasoconstriction.

  9. Effect of temperature on rectified diffusion during ultrasound-induced heating.

    Science.gov (United States)

    Webb, Ian R; Payne, Stephen J; Coussios, Constantin-C

    2011-11-01

    Experimental observations of delayed-onset cavitation during ultrasound insonation have been suggested as being caused by a change in the size distribution of the bubble population due to rectified diffusion. To investigate this hypothesis, a single bubble model is used here to explore the effect of heating and the subsequent elevated temperatures on the rectified diffusion process. Numerical solution of the model, which includes the temperature dependences of seven relevant physical parameters, allows quantification of the change in the pressure threshold for rectified diffusion, as well as the importance of the bulk liquid saturation concentration in determining bubble evolution. Although elevated temperatures and liquid supersaturation reduce the rectified diffusion threshold, it remains coincident with the inertial cavitation thresholds at submicron bubble sizes at all temperatures. This observation suggests that changes in the nucleation environment, rather than bubble growth due to rectified diffusion, is a more likely cause of delayed-onset cavitation events.

  10. Radiation cataracts: mechanisms involved in their long delayed occurrence but then rapid progression.

    Science.gov (United States)

    Wolf, Norman; Pendergrass, William; Singh, Narendra; Swisshelm, Karen; Schwartz, Jeffrey

    2008-02-05

    This study was directed to assess the DNA damage and DNA repair response to X-ray inflicted lens oxidative damage and to investigate the subsequent changes in lens epithelial cell (LEC) behavior in vivo that led to long delayed but then rapidly developing cataracts. Two-month-old C57Bl/6 female mice received 11 Grays (Gy) of soft x-irradiation to the head only. The animals' eyes were examined for cataract status in 30 day intervals by slit lamp over an 11 month period post-irradiation. LEC migration, DNA fragment, free DNA retention, and reactive oxygen species (ROS) presence were established in the living lenses with fluorescent dyes using laser scanning confocal microscopy (LSCM). The extent and removal of initial LEC DNA damage were determined by comet assay. Immunohistochemistry was used to determine the presence of oxidized DNA and the response of a DNA repair protein in the lenses. This treatment resulted in advanced cortical cataracts that developed 5-11 months post-irradiation but then appeared suddenly within a 30 day period. The initially incurred DNA strand breaks were repaired within 30 min, but DNA damage remained as shown 72 h post-irradiation by the presence of the DNA adduct, 8-hydroxyguanosine (8-OHG), and a DNA repair protein, XRCC1. This was followed months later by abnormal behavior by LEC descendant cells with abnormal differentiation and migration patterns as seen with LSCM and fluorescent dyes. The sudden development of cortical cataracts several months post-irradiation coupled with the above findings suggests an accumulation of damaged descendants from the initially x-irradiated LECs. As these cells migrate abnormally and leave acellular lens surface sites, eventually a crisis point may arrive for lens entry of environmental O(2) with resultant ROS formation that overwhelms protection by resident antioxidant enzymes and results in the coagulation of lens proteins. The events seen in this study indicate the retention and transmission of

  11. Characterization of a Semi-Rapid Method for Assessing Delay Discounting in Rodents

    OpenAIRE

    Foscue, Ethan P.; Wood, Kathryne N.; Schramm-Sapyta, Nicole L.

    2012-01-01

    Delay discounting is a key component of many psychiatric disorders, including drug addiction, compulsive gambling, ADHD, and obesity. However, its underlying mechanisms are not yet fully characterized. One impediment to full characterization of such mechanisms is the fact that rodent models of the task are often complicated and involve extended training of subjects, often requiring more than a month before a stable baseline is obtained. We have therefore characterized a version of the rodent ...

  12. State and Federal project development procedures for bus rapid transit : managing differences and reducing implementation delays

    Science.gov (United States)

    2011-08-01

    This report documents an investigation into the transportation project development process in the : context of the implementation of bus rapid transit systems on the State Highway System as well as such : systems being part of the Federal New Starts ...

  13. Noninvasive monitoring of glucose concentration using differential absorption low-coherence interferometry based on rapid scanning optical delay line

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Yong; Zeng Nan; He Yonghong, E-mail: heyh@sz.tsinghua.edu.cn [Laboratory of Optical Imaging and Sensing, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055 (China)

    2011-01-01

    A non-invasive method of detecting glucose concentration using differential absorption low-coherence interferometry (DALCI) based on rapid scanning optical delay line is presented. Two light sources, one centered within (1625 nm) a glucose absorption band, while the other outside (1310 nm) the glucose absorption band, are used in the experiment. The low-coherence interferometry (LCI) is employed to obtain the signals back-reflecting from the iris which carries the messages of material concentration in anterior chamber. Using rapid scanning optical delay line (RSOD) as the reference arm, we can detect the signals in a very short time. Therefore the glucose concentration can be monitored in real-time, which is very important for the detection in vivo. In our experiments, the cornea and aqueous humor can be treated as nearly non-scattering substance. The difference in the absorption coefficient is much larger than the difference in the scattering coefficient, so the influence of scattering can be neglected. By subtracting the algorithmic low-coherence interference signals of the two wavelengths, the absorption coefficient can be calculated which is proportional to glucose concentration. To reduce the speckle noise, a 30 variation of signals were used before the final calculation of the glucose concentration. The improvements of our experiment are also discussed in the article. The method has a potential application for noninvasive detection of glucose concentration in vivo and in real-time.

  14. Delayed Effect of Blood-Flow-Restricted Resistance Training on Rapid Force Capacity

    DEFF Research Database (Denmark)

    Nielsen, Jakob Lindberg; Frandsen, Ulrik; Prokhorova, Tatyana

    2017-01-01

    PURPOSE: The aim of the present study was to investigate the effect and time course of high-frequent low-load resistance training with blood-flow restriction (BFR) on rapid force capacity (i.e. rate of torque development (RTD)). METHODS: Ten male subjects (22.8±2.3 years) performed four sets...... and rapid force capacity (e.g. RTD) as well as evoked twitch contractile parameters was assessed before (Pre) and 5 and 12 days after training (Post5, Post12). Muscle biopsies were obtained Pre, after 8 days (Mid8) and 3 and 10 days post training (Post3, Post10) to examine changes in myofiber area...... to baseline levels at Post12. All contractile parameters essentially remained unchanged in CON. Elevated CaMKII was observed with BFR training at Post3 (57%) and Post10 (71%) (Presistance...

  15. High current and high power superconducting rectifiers

    NARCIS (Netherlands)

    ten Kate, Herman H.J.; Bunk, P.B.; Britton, R.B.; van de Klundert, L.J.M.

    1981-01-01

    Results on three experimental superconducting rectifiers are reported. Two of them are 1 kA low frequency flux pumps, one thermally and magnetically switched. The third is a low-current high-frequency magnetically switched rectifier which can use the mains directly.

  16. From Rapid to Delayed and Remote Postconditioning: the Evolving Concept of Ischemic Postconditioning in Brain Ischemia

    Science.gov (United States)

    Zhao, Heng; Ren, Chuancheng; Chen, Xingmiao; Shen, Jiangang

    2012-01-01

    Ischemic postconditioning is a concept originally defined to contrast with that of ischemic preconditioning. While both preconditioning and postconditioning confer a neuroprotective effect on brain ischemia, preconditioning is a sublethal insult performed in advance of brain ischemia, and postconditioning, which conventionally refers to a series of brief occlusions and reperfusions of the blood vessels, is conducted after ischemia/reperfusion. In this article, we first briefly review the history of preconditioning, including the experimentation that initially uncovered its neuroprotective effects and later revealed its underlying mechanisms-of-action. We then discuss how preconditioning research evolved into that of postconditioning – a concept that now represents a broad range of stimuli or triggers, including delayed postconditioning, pharmacological postconditioning, remote postconditioning – and its underlying protective mechanisms involving the Akt, MAPK, PKC and KATP channel cell-signaling pathways. Because the concept of postconditioning is so closely associated with that of preconditioning, and both share some common protective mechanisms, we also discuss whether a combination of preconditioning and postconditioning offers greater protection than preconditioning or postconditioning alone. PMID:22204317

  17. Modeling removal of accumulated potassium from T-tubules by inward rectifier potassium channels

    NARCIS (Netherlands)

    Wallinga, W.; Vliek, M.; Wienk, E.D.; Alberink, M.J.; Ypey, D.L.; Ypey, D.L.

    1996-01-01

    The membrane models of Cannon et al. (1993) and Alberink et al. (1995) for mammalian skeletal muscle fibers are based upon Hodgkin-Huxley descriptions of sodium, potassium delayed rectifier and leak conductances and the capacitive current taking into account fast inactivation of sodium channels. Now

  18. Toxicant induced changes on delayed fluorescence decay kinetics of cyanobacteria and green algae: a rapid and sensitive biotest.

    Directory of Open Access Journals (Sweden)

    Franziska Leunert

    Full Text Available Algal tests have developed into routine tools for testing toxicity of pollutants in aquatic environments. Meanwhile, in addition to algal growth rates, an increasing number of fluorescence based methods are used for rapid and sensitive toxicity measures. The present study stresses the suitability of delayed fluorescence (DF as a promising parameter for biotests. DF is based on the recombination fluorescence at the reaction centre of photosystem II, which is emitted only by photosynthetically active cells. We analyzed the effects of three chemicals (3-(3,4-dichlorophenyl-1,1-dimethylurea (DCMU, 3,5 Dichlorophenol (3,5 DCP and copper on the shape of the DF decay kinetics for potential use in phytoplankton toxicity tests. The short incubation tests were done with four phytoplankton species, with special emphasis on the cyanobacterium Microcystis aeruginosa. All species exhibited a high sensitivity to DCMU, but cyanobacteria were more affected by copper and less by 3,5 DCP than the tested green algae. Analyses of changes in the DF decay curve in response to the added chemicals indicated the feasibility of the DF decay approach as a rapid and sensitive testing tool.

  19. A novel method for rapid and non-invasive detection of plants senescence using delayed fluorescence technique

    Science.gov (United States)

    Zhang, Lingrui; Xing, Da; Wang, Junsheng; Zeng, Lizhang; Li, Qiang

    2007-05-01

    Plants senescence is a phase of plants ontogeny marked by declining photosynthetic activity that is paralleled by a decline in chloroplast function. The photosystem II ( PSII ) in a plant is considered the primary site where light-induced delayed fluorescence (DF) is produced. With the leaves of Catharanthus roseus (Catharanthus roseus (L.) G.Don) as testing models, we have studied the effects of plants senescence induced by dark and/or exogenous hormones treatments on characteristics of DF by using a home-made portable DF detection system, which can enable various DF parameters, such as DF decay kinetic curve and DF intensity, to be rapidly produced for the plants in a short time. The results show that the changes in DF intensity of green plants can truly reflect the changes in photosynthetic capacity and chlorophyll content. Therefore, DF may be used an important means of evaluating in vivo plants senescence physiology. The changes in DF intensity may provide a new approach for the rapid and early detection of plants senescence caused by age or other senescence-related factors. DF technique could be potential useful for high throughput screening and less time-consuming and automated identifying the interesting mutants with genetic modifications that change plants senescence progress.

  20. A boron nitride nanotube peapod thermal rectifier

    Energy Technology Data Exchange (ETDEWEB)

    Loh, G. C., E-mail: jgloh@mtu.edu [Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States); Institute of High Performance Computing, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632 (Singapore); Baillargeat, D. [CNRS-International-NTU-Thales Research Alliance (CINTRA), 50 Nanyang Drive, Singapore 637553 (Singapore)

    2014-06-28

    The precise guidance of heat from one specific location to another is paramount in many industrial and commercial applications, including thermal management and thermoelectric generation. One of the cardinal requirements is a preferential conduction of thermal energy, also known as thermal rectification, in the materials. This study introduces a novel nanomaterial for rectifying heat—the boron nitride nanotube peapod thermal rectifier. Classical non-equilibrium molecular dynamics simulations are performed on this nanomaterial, and interestingly, the strength of the rectification phenomenon is dissimilar at different operating temperatures. This is due to the contingence of the thermal flux on the conductance at the localized region around the scatterer, which varies with temperature. The rectification performance of the peapod rectifier is inherently dependent on its asymmetry. Last but not least, the favourable rectifying direction in the nanomaterial is established.

  1. Stability analysis of direct current control in current source rectifier

    DEFF Research Database (Denmark)

    Lu, Dapeng; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    Current source rectifier with high switching frequency has a great potential for improving the power efficiency and power density in ac-dc power conversion. This paper analyzes the stability of direct current control based on the time delay effect. Small signal model including dynamic behaviors...... of dc link is developed to identify the control plants of grid ac current control and dc current control. Analysis on the poles and zeros under dq frame is carried out. Base on this model, it turns out that the phase lag caused by the time delay can stabilized the grid ac current control while reduces...... the stable region for dc current control. Simulation and experimental results are presented to validate the theoretical analysis....

  2. Initial Accuracy of HIV Rapid Test Kits Stored in Suboptimal Conditions and Validity of Delayed Reading of Oral Fluid Tests.

    Science.gov (United States)

    Choko, Augustine T; Taegtmeyer, Miriam; MacPherson, Peter; Cocker, Derek; Khundi, McEwen; Thindwa, Deus; Sambakunsi, Rodrick S; Kumwenda, Moses K; Chiumya, Kondwani; Malema, Owen; Makombe, Simon D; Webb, Emily L; Corbett, Elizabeth L

    2016-01-01

    To evaluate the effect of storing commonly used rapid diagnostic tests above manufacturer-recommended temperature (at 37°C), and the accuracy of delayed reading of oral fluid kits with relevance to HIV self-testing programmes. A quality assurance study of OraQuick (OraSure), Determine HIV 1/2™ (Alere) and Uni-Gold™ (Recombigen®). Consecutive adults (≥18y) attending Ndirande Health Centre in urban Blantyre, Malawi in January to April 2012 underwent HIV testing with two of each of the three rapid diagnostic test kits stored for 28 days at either 18°C (optimally-stored) or at 37°C (pre-incubated). Used OraQuick test kits were stored in a laboratory for delayed day 1 and subsequent monthly re-reading was undertaken for one year. Of 378 individuals who underwent parallel testing, 5 (1.3%) were dropped from the final analysis due to discordant or missing reference standard results (optimally-stored Determine and Uni-Gold). Compared to the diagnostic reference standard, OraQuick had a sensitivity of 97.2% (95% CI: 93.6-99.6). There were 7 false negative results among all test kits stored at 37°C and three false negatives among optimally stored kits. Excellent agreement between pre-incubated tests and optimally-stored tests with Kappa values of 1.00 for Determine and Uni-Gold; and 0.97 (95% CI: 0.95; 1.00) for OraQuick were observed. There was high visual stability on re-reading of OraQuick, with only 1/375 pre-incubated and 1/371 optimally-stored OraQuick kits changing from the initial result over 12 months. Erroneous results observed during HIV testing in low income settings are likely to be due to factors other than suboptimal storage conditions. Re-reading returned OraQuick kits may offer a convenient and accurate quality assurance approach, including in HIV self-testing programmes.

  3. Rapid determination of the damage to photosynthesis caused by salt and osmotic stresses using delayed fluorescence of chloroplasts.

    Science.gov (United States)

    Zhang, Lingrui; Xing, Da

    2008-03-01

    Chloroplasts are one of the most susceptible systems to salt and osmotic stresses. Based on quantitative measurements of delayed fluorescence (DF) of the chloroplasts, we have investigated the damage to photosynthesis caused by these two kinds of stresses in Arabidopsis seedlings by using a custom-built multi-channel biosensor. Results showed that the DF intensity and net photosynthesis rate (Pn) decreased in a similar way with increasing NaCl or sorbitol concentration. Incubation of the seedlings in 200 mM NaCl induced a rapid and reversible decline and subsequent slow and irreversible loss in both the DF intensity and Pn. The rapid decline was dominantly related to osmotic stress, whereas the slow declines in the DF intensity and Pn were specific to ionic stress and could be reversed to a similar extent by a Na+-channel blocker. The DF intensity and Pn also exhibited a similar response to irradiation light under NaCl or sorbitol stress. All results indicated that the DF intensity correlated well with Pn under salt and osmotic stresses. We thus conclude that DF is an excellent marker for detecting the damage to photosynthesis caused by these two stresses. The mechanism of the correlation between the DF intensity and Pn under salt and osmotic stresses was also analyzed in theory and investigated with experiments by measuring intercellular CO2 concetration (Ci), stomatal conductance (Gs), chlorophyll fluorescence parameter, and chlorophyll content. This proposed DF technique holds the potential to be a useful means for analyzing the dynamics of salt and osmotic stresses in vivo and elucidating the mechanism by which plants respond to stress.

  4. Rapid fabrication of TiO2@carboxymethyl cellulose coatings capable of shielding UV, antifog and delaying support aging.

    Science.gov (United States)

    Li, Xiaozhou; Lv, Junping; Li, Dehuai; Wang, Lin

    2017-08-01

    Agricultural plastic films capable of shielding UV, filtering visible light and antifog are important to prolong their life and protect safeties of agriculturists and crops. In this work, high stable and small size TiO2@polymer nanoparticles (NPs) were prepared by an efficient one-pot microwave synthesis using titanic sulfate as Ti resource, carboxymethyl cellulose sodium (CMC) as complexing agent and stabilizer. The TiO2@CMC NPs obtained were then utilized to fabricate poly(ethylene imine) (PEI)/TiO2@CMC coatings on the surface of polypropylene films by a layer-by-layer assembly technique. The TiO2@CMC NPs show rapid deposition rate because small, spherical and anion-rich TiO2@CMC NPs possess large specific surface area and fast diffusion rate. More importantly, property experiments confirm that (PEI/TiO2@CMC)*15 coatings can not only effectively shield UV rays, filter visible light and prevent fogging but also delay the aging of their supports. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Performance of a double-star synchronous generator with bridge rectified output

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.Y. (Chengdu Univ. of Science and Technology (China)); Malik, O.P. (Univ. of Calgary, Alberta (Canada))

    1994-09-01

    In this paper, the performance of a double-star synchronous generator with bridge rectified output is studied from the fundamental machine equations. The generator has two stator windings shifted by [pi]/6 electrical radians, which with their bridges can be connected either in series or in parallel. Therefore the double-star synchronous generator with rectifier load can have two major operation modes. Using the fundamental machine equations, the expressions of displacement angles and commutation angles are derived under these operation modes. The performance of the double-star synchronous generator with bridge rectified output can be predicted from given load current, field current, generator speed, bridge delay angle and its parameters. Theoretical results are compared with experimental results obtained from a laboratory machine.

  6. Structural Optimization of Non-Newtonian Rectifiers

    DEFF Research Database (Denmark)

    Jensen, Kristian Ejlebjærg; Okkels, Fridolin

    When the size of fluidic devices is scaled down, inertial effects start to vanish such that the governing equation becomes linear. Some microfluidic devices rely on the non-linear term related to the inertia of the fluid, and one example is fluid rectifiers (diodes) e.g. related to some micropumps....... In this context it is natural to look for other sources of non-linearity and one possibility is to introduce a non-Newtonian working fluid. Non-Newtonian properties are due to stretching of large particles/molecules in the fluid and this is commonly seen for biological samples in “lab-on-a-chip” systems....... These rectifiers rely on the device geometry for their working mechanism, but on further downscaling the inertial effect vanishes and the governing equation starts to show symmetry properties. These symmetry properties reduce the geometry influence to the point where fluid rectifiers cease to function...

  7. Full-wave current conveyor precision rectifier

    Directory of Open Access Journals (Sweden)

    Đukić Slobodan R.

    2008-01-01

    Full Text Available A circuit that provides precision rectification of small signal with low temperature sensitivity for frequencies up to 100 kHz without waveform distortion is presented. It utilizes an improved second type current conveyor based on current-steering output stage and biased silicon diodes. The use of a DC current source to bias the rectifying diodes provides higher temperature stability and lower DC offset level at the output. Proposed design of the precision rectifier ensures good current transfer linearity in the range that satisfy class A of the amplifier and good voltage transfer characteristic for low level signals. Distortion during the zero crossing of the input signal is practically eliminated. Design of the proposed rectifier is realized with standard components.

  8. Laserlike Vibrational Instability in Rectifying Molecular Conductors

    DEFF Research Database (Denmark)

    Lu, Jing Tao; Hedegård, Per; Brandbyge, Mads

    2011-01-01

    We study the damping of molecular vibrations due to electron-hole pair excitations in donor-acceptor (D-A) type molecular rectifiers. At finite voltage additional nonequilibrium electron-hole pair excitations involving both electrodes become possible, and contribute to the stimulated emission and...

  9. "ATP1A3" Mutations in Infants: A New Rapid-Onset Dystonia-Parkinsonism Phenotype Characterized by Motor Delay and Ataxia

    Science.gov (United States)

    Brashear, Allison; Mink, Jonathan W.; Hill, Deborah F.; Boggs, Niki; McCall, W. Vaughn; Stacy, Mark A.; Snively, Beverly; Light, Laney S.; Sweadner, Kathleen J.; Ozelius, Laurie J.; Morrison, Leslie

    2012-01-01

    We report new clinical features of delayed motor development, hypotonia, and ataxia in two young children with mutations (R756H and D923N) in the "ATP1A3" gene. In adults, mutations in "ATP1A3" cause rapid-onset dystonia-Parkinsonism (RDP, DYT12) with abrupt onset of fixed dystonia. The parents and children were examined and videotaped, and…

  10. High Power Factor Hybrid Rectifier | Odeh | Nigerian Journal of ...

    African Journals Online (AJOL)

    This paper presents the analysis of a new single-phase hybrid rectifier with high power factor (PF) and low harmonic distortion current. The proposed rectifier structure is composed of an ordinary single-phase diode rectifier with parallel connection of a switched converter. It is outlined that the switched converter is capable of ...

  11. Minimum component high frequency current mode rectifier | Sampe ...

    African Journals Online (AJOL)

    In this paper a current mode full wave rectifier circuit is proposed. The current mode rectifier circuit is implemented utilizing a floating current source (FCS) as an active element. The minimum component full wave rectifier utilizes only a single floating current source, two diodes and two grounded resistors. The extremely ...

  12. Reduction of Harmonics by 18-Pulse Rectifier

    Directory of Open Access Journals (Sweden)

    Stanislav Kocman

    2008-01-01

    Full Text Available Operation of such electrical devices as data processing and electronics devices, adjustable speed drives or uninterruptible power supply can cause problems by generating harmonic currents into the network, from which they are supplied. Effects of these harmonic currents are various, they can get worse the quality of supply voltage in the network or to have negative influences on devices connected to this network. There are various technical solutions for reduction of harmonics. One of them is using of multi-pulse rectifiers, whereas the 18-pulse rectifier in the structure of adjustable speed drive is briefly presented in this paper including some results of its behaviour. The examined experimental measurements confirmed its very good efficiency in the harmonic mitigation.

  13. Optimal locomotion of mechanical rectifier systems

    Science.gov (United States)

    Blair, Justin T.

    Vehicles utilizing animal locomotion mechanisms may possess increased performance parameters and the ability to overcome more difficult terrain than conventional wheel or propeller driven vehicles. The essential mechanism underlying animal locomotion can be viewed as mechanical rectification that converts periodic body movements to thrust force through interactions with the environment. This dissertation defines a general class of mechanical rectifiers as multi-body systems equipped with such thrust generation mechanisms. A general model is developed from the Euler-Lagrange equation and simplified by assuming small body oscillations around a given nominal posture. The model reveals that the rectifying dynamics can be captured by a bilinear (but not linear) term of body shape variables. An optimal gait problem is formulated for the bilinear rectifier model as a minimization of a quadratic cost function over the set of periodic functions subject to a constraint on the average locomotion velocity. We prove that a globally optimal solution is given by a harmonic gait that can be found by generalized eigenvalue computation with a line search over cycle frequencies. We verify the solution method through case studies of a two dimensional chain of links for which snake-like undulations and jellyfish-like flapping gaits are found to be optimal, and obtain analytical insights into determinants of optimal gaits from a simple disk-mass rectifier system. Lastly, we develop a dynamic model for batoid swimming featuring a 6 degree-of-freedom main body (position and orientation), with independent wing deformation (described as the motion of many discrete points in the body-fixed coordinate frame), and calculate various gaits. Multiple wing shapes and optimality criteria are considered, such as the maximum thrust to deflection ratio or minimum input power, and the resulting gaits are compared.

  14. Time-division-multiplex control scheme for voltage multiplier rectifiers

    Directory of Open Access Journals (Sweden)

    Bin-Han Liu

    2017-03-01

    Full Text Available A voltage multiplier rectifier with a novel time-division-multiplexing (TDM control scheme for high step-up converters is proposed in this study. In the proposed TDM control scheme, two full-wave voltage doubler rectifiers can be combined to realise a voltage quadrupler rectifier. The proposed voltage quadrupler rectifier can reduce transformer turn ratio and transformer size for high step-up converters and also reduce voltage stress for the output capacitors and rectifier diodes. An N-times voltage rectifier can be straightforwardly produced by extending the concepts from the proposed TDM control scheme. A phase-shift full-bridge (PSFB converter is adopted in the primary side of the proposed voltage quadrupler rectifier to construct a PSFB quadrupler converter. Experimental results for the PSFB quadrupler converter demonstrate the performance of the proposed TDM control scheme for voltage quadrupler rectifiers. An 8-times voltage rectifier is simulated to determine the validity of extending the proposed TDM control scheme to realise an N-times voltage rectifier. Experimental and simulation results show that the proposed TDM control scheme has great potential to be used in high step-up converters.

  15. High Voltage GaN Schottky Rectifiers

    Energy Technology Data Exchange (ETDEWEB)

    CAO,X.A.; CHO,H.; CHU,S.N.G.; CHUO,C.-C.; CHYI,J.-I.; DANG,G.T.; HAN,JUNG; LEE,C.-M.; PEARTON,S.J.; REN,F.; WILSON,R.G.; ZHANG,A.P.

    1999-10-25

    Mesa and planar GaN Schottky diode rectifiers with reverse breakdown voltages (V{sub RB}) up to 550V and >2000V, respectively, have been fabricated. The on-state resistance, R{sub ON}, was 6m{Omega}{center_dot} cm{sup 2} and 0.8{Omega}cm{sup 2}, respectively, producing figure-of-merit values for (V{sub RB}){sup 2}/R{sub ON} in the range 5-48 MW{center_dot}cm{sup -2}. At low biases the reverse leakage current was proportional to the size of the rectifying contact perimeter, while at high biases the current was proportional to the area of this contact. These results suggest that at low reverse biases, the leakage is dominated by the surface component, while at higher biases the bulk component dominates. On-state voltages were 3.5V for the 550V diodes and {ge}15 for the 2kV diodes. Reverse recovery times were <0.2{micro}sec for devices switched from a forward current density of {approx}500A{center_dot}cm{sup -2} to a reverse bias of 100V.

  16. Salivary glucose oxidase from caterpillars mediates the induction of rapid and delayed-induced defenses in the tomato plant.

    Directory of Open Access Journals (Sweden)

    Donglan Tian

    Full Text Available Caterpillars produce oral secretions that may serve as cues to elicit plant defenses, but in other cases these secretions have been shown to suppress plant defenses. Ongoing work in our laboratory has focused on the salivary secretions of the tomato fruitworm, Helicoverpa zea. In previous studies we have shown that saliva and its principal component glucose oxidase acts as an effector by suppressing defenses in tobacco. In this current study, we report that saliva elicits a burst of jasmonic acid (JA and the induction of late responding defense genes such as proteinase inhibitor 2 (Pin2. Transcripts encoding early response genes associated with the JA pathway were not affected by saliva. We also observed a delayed response to saliva with increased densities of Type VI glandular trichomes in newly emerged leaves. Proteomic analysis of saliva revealed glucose oxidase (GOX was the most abundant protein identified and we confirmed that it plays a primary role in the induction of defenses in tomato. These results suggest that the recognition of GOX in tomato may represent a case for effector-triggered immunity. Examination of saliva from other caterpillar species indicates that saliva from the noctuids Spodoptera exigua and Heliothis virescens also induced Pin2 transcripts.

  17. Salivary glucose oxidase from caterpillars mediates the induction of rapid and delayed-induced defenses in the tomato plant.

    Science.gov (United States)

    Tian, Donglan; Peiffer, Michelle; Shoemaker, Erica; Tooker, John; Haubruge, Eric; Francis, Frederic; Luthe, Dawn S; Felton, Gary W

    2012-01-01

    Caterpillars produce oral secretions that may serve as cues to elicit plant defenses, but in other cases these secretions have been shown to suppress plant defenses. Ongoing work in our laboratory has focused on the salivary secretions of the tomato fruitworm, Helicoverpa zea. In previous studies we have shown that saliva and its principal component glucose oxidase acts as an effector by suppressing defenses in tobacco. In this current study, we report that saliva elicits a burst of jasmonic acid (JA) and the induction of late responding defense genes such as proteinase inhibitor 2 (Pin2). Transcripts encoding early response genes associated with the JA pathway were not affected by saliva. We also observed a delayed response to saliva with increased densities of Type VI glandular trichomes in newly emerged leaves. Proteomic analysis of saliva revealed glucose oxidase (GOX) was the most abundant protein identified and we confirmed that it plays a primary role in the induction of defenses in tomato. These results suggest that the recognition of GOX in tomato may represent a case for effector-triggered immunity. Examination of saliva from other caterpillar species indicates that saliva from the noctuids Spodoptera exigua and Heliothis virescens also induced Pin2 transcripts.

  18. High-Efficiency Harmonically Terminated Diode and Transistor Rectifiers

    Energy Technology Data Exchange (ETDEWEB)

    Roberg, M; Reveyrand, T; Ramos, I; Falkenstein, EA; Popovic, Z

    2012-12-01

    This paper presents a theoretical analysis of harmonically terminated high-efficiency power rectifiers and experimental validation on a class-C single Schottky-diode rectifier and a class-F-1 GaN transistor rectifier. The theory is based on a Fourier analysis of current and voltage waveforms, which arise across the rectifying element when different harmonic terminations are presented at its terminals. An analogy to harmonically terminated power amplifier (PA) theory is discussed. From the analysis, one can obtain an optimal value for the dc load given the RF circuit design. An upper limit on rectifier efficiency is derived for each case as a function of the device on-resistance. Measured results from fundamental frequency source-pull measurement of a Schottky diode rectifier with short-circuit terminations at the second and third harmonics are presented. A maximal device rectification efficiency of 72.8% at 2.45 GHz matches the theoretical prediction. A 2.14-GHz GaN HEMT rectifier is designed based on a class-F-1 PA. The gate of the transistor is terminated in an optimal impedance for self-synchronous rectification. Measurements of conversion efficiency and output dc voltage for varying gate RF impedance, dc load, and gate bias are shown with varying input RF power at the drain. The rectifier demonstrates an efficiency of 85% for a 10-W input RF power at the transistor drain with a dc voltage of 30 V across a 98-Omega resistor.

  19. Characteristics of a half-wave rectified brushless synchronous generator

    OpenAIRE

    Hirakawa, Yuki; Higuchi, Tsuyoshi; Yokoi, Yuichi; Abe, Takashi

    2014-01-01

    The paper proposes the half-wave rectified brushless synchronous generator and analyzes the basic characteristics using the finite element method. It is based on the half-wave rectified excitation theory and doesn't need brush and slip ring system or permanent magnets for field excitation.

  20. Spatial properties of rectified cosine Gaussian beams

    Science.gov (United States)

    Boubaha, B.; Bencheikh, A.; Aït-Ameur, K.

    2014-02-01

    The cosine Gaussian beam (CGB) resulting from the coherent coaxial superposition of two Gaussian beams having the same width W and opposite radii of curvature R and - R is a ringed beam characterized by an M2 factor which can be very high, and adjustable by changing R. According to the paper by Hasnaoui et al(2011 Opt. Commun.284 1331-4) we expect that the CGB after ‘rectification’ by a binary diffractive optical element could be a good candidate for focal volume reduction, so useful to many laser applications. Unfortunately, this is not the case, and the physical factors responsible for this unexpected behaviour have been analysed. In particular, we have demonstrated that the three features (M2 factor, divergence and on-axis intensity) do not hold the same information about the spatial characteristics of rectified or unrectified CGBs.

  1. Nanofibrous p-n Junction and Its Rectifying Characteristics

    Directory of Open Access Journals (Sweden)

    Jian Fang

    2013-01-01

    Full Text Available Randomly oriented tin oxide (SnO2 nanofibers and poly(3,4-ethylenedioxythiophene-poly(styrenesulfonate/polyvinylpyrrolidone (PEDOT:PSS/PVP nanofibers were prepared by a two-step electrospinning technique to form a layered fibrous mat. The current-voltage measurement revealed that the fibrous mat had an obvious diode-rectifying characteristic. The thickness of the nanofiber layers was found to have a considerable influence on the device resistance and rectifying performance. Such an interesting rectifying property was attributed to the formation of a p-n junction between the fibrous SnO2 and PEDOT:PSS/PVP layers. This is the first report that a rectifying junction can be formed between two layers of electrospun nanofiber mats, and the resulting nanofibrous diode rectifier may find applications in sensors, energy harvest, and electronic textiles.

  2. Aviram-Ratner rectifying mechanism for DNA base-pair sequencing through graphene nanogaps

    Science.gov (United States)

    Agapito, Luis A.; Gayles, Jacob; Wolowiec, Christian; Kioussis, Nicholas

    2012-04-01

    We demonstrate that biological molecules such as Watson-Crick DNA base pairs can behave as biological Aviram-Ratner electrical rectifiers because of the spatial separation and weak hydrogen bonding between the nucleobases. We have performed a parallel computational implementation of the ab initio non-equilibrium Green’s function (NEGF) theory to determine the electrical response of graphene—base-pair—graphene junctions. The results show an asymmetric (rectifying) current-voltage response for the cytosine-guanine base pair adsorbed on a graphene nanogap. In sharp contrast we find a symmetric response for the thymine-adenine case. We propose applying the asymmetry of the current-voltage response as a sensing criterion to the technological challenge of rapid DNA sequencing via graphene nanogaps.

  3. Analytic capacity, rectifiability, menger curvature and the Cauchy integral

    CERN Document Server

    Pajot, Hervé

    2002-01-01

    Based on a graduate course given by the author at Yale University this book deals with complex analysis (analytic capacity), geometric measure theory (rectifiable and uniformly rectifiable sets) and harmonic analysis (boundedness of singular integral operators on Ahlfors-regular sets). In particular, these notes contain a description of Peter Jones' geometric traveling salesman theorem, the proof of the equivalence between uniform rectifiability and boundedness of the Cauchy operator on Ahlfors-regular sets, the complete proofs of the Denjoy conjecture and the Vitushkin conjecture (for the latter, only the Ahlfors-regular case) and a discussion of X. Tolsa's solution of the Painlevé problem.

  4. Towards Rectifying Performance at the Molecular Scale.

    Science.gov (United States)

    Zhang, Guang-Ping; Xie, Zhen; Song, Yang; Hu, Gui-Chao; Wang, Chuan-Kui

    2017-10-24

    Molecular diode, proposed by Mark Ratner and Arieh Aviram in 1974, is the first single-molecule device investigated in molecular electronics. As a fundamental device in an electric circuit, molecular diode has attracted an enduring and extensive focus during the past decades. In this review, the theoretical and experimental progresses of both charge-based and spin-based molecular diodes are summarized. For the charge-based molecular diodes, the rectifying properties originated from asymmetric molecules including D-σ-A, D-π-A, D-A, and σ-π type compounds, asymmetric electrodes, asymmetric nanoribbons, and their combination are analyzed. Correspondingly, the rectification mechanisms are discussed in detail. Furthermore, a series of strategies for modulating rectification performance is figured out. Discussion on concept of molecular spin diode is also involved based on a magnetic co-oligomer. At the same time, the intrinsic mechanism as well as the modulation of the spin-current rectification performance is introduced. Finally, several crucial issues that need to be addressed in the future are given.

  5. 2011 NOAA Ortho-rectified Mosaic of Intracoastal Waterway, Texas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  6. 2011 NOAA Ortho-rectified Mosaic of Tallaboa, Puerto Rico

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  7. 2011 NOAA Ortho-rectified Mosaic of Baltimore, Maryland

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  8. Wireless power transmission for biomedical implants: The role of near-zero threshold CMOS rectifiers.

    Science.gov (United States)

    Mohammadi, Ali; Redoute, Jean-Michel; Yuce, Mehmet R

    2015-01-01

    Biomedical implants require an electronic power conditioning circuitry to provide a stable electrical power supply. The efficiency of wireless power transmission is strongly dependent on the power conditioning circuitry specifically the rectifier. A cross-connected CMOS bridge rectifier is implemented to demonstrate the impact of thresholds of rectifiers on wireless power transfer. The performance of the proposed rectifier is experimentally compared with a conventional Schottky diode full wave rectifier over 9 cm distance of air and tissue medium between the transmitter and receiver. The output voltage generated by the CMOS rectifier across a 1 KΩ resistive load is around twice as much as the Schottky rectifier.

  9. A metamaterial electromagnetic energy rectifying surface with high harvesting efficiency

    Science.gov (United States)

    Duan, Xin; Chen, Xing; Zhou, Lin

    2016-12-01

    A novel metamaterial rectifying surface (MRS) for electromagnetic energy capture and rectification with high harvesting efficiency is presented. It is fabricated on a three-layer printed circuit board, which comprises an array of periodic metamaterial particles in the shape of mirrored split rings, a metal ground, and integrated rectifiers employing Schottky diodes. Perfect impedance matching is engineered at two interfaces, i.e. one between free space and the surface, and the other between the metamaterial particles and the rectifiers, which are connected through optimally positioned vias. Therefore, the incident electromagnetic power is captured with almost no reflection by the metamaterial particles, then channeled maximally to the rectifiers, and finally converted to direct current efficiently. Moreover, the rectifiers are behind the metal ground, avoiding the disturbance of high power incident electromagnetic waves. Such a MRS working at 2.45 GHz is designed, manufactured and measured, achieving a harvesting efficiency up to 66.9% under an incident power density of 5 mW/cm2, compared with a simulated efficiency of 72.9%. This high harvesting efficiency makes the proposed MRS an effective receiving device in practical microwave power transmission applications.

  10. Extremely rapid increase in fatty acid transport and intramyocellular lipid accumulation but markedly delayed insulin resistance after high fat feeding in rats.

    Science.gov (United States)

    Bonen, Arend; Jain, Swati S; Snook, Laelie A; Han, Xiao-Xia; Yoshida, Yuko; Buddo, Kathryn H; Lally, James S; Pask, Elizabeth D; Paglialunga, Sabina; Beaudoin, Marie-Soleil; Glatz, Jan F C; Luiken, Joost J F P; Harasim, Ewa; Wright, David C; Chabowski, Adrian; Holloway, Graham P

    2015-10-01

    The mechanisms for diet-induced intramyocellular lipid accumulation and its association with insulin resistance remain contentious. In a detailed time-course study in rats, we examined whether a high-fat diet increased intramyocellular lipid accumulation via alterations in fatty acid translocase (FAT/CD36)-mediated fatty acid transport, selected enzymes and/or fatty acid oxidation, and whether intramyocellular lipid accretion coincided with the onset of insulin resistance. We measured, daily (on days 1-7) and/or weekly (for 6 weeks), the diet-induced changes in circulating substrates, insulin, sarcolemmal substrate transporters and transport, selected enzymes, intramyocellular lipids, mitochondrial fatty acid oxidation and basal and insulin-stimulated sarcolemmal GLUT4 and glucose transport. We also examined whether upregulating fatty acid oxidation improved glucose transport in insulin-resistant muscles. Finally, in Cd36-knockout mice, we examined the role of FAT/CD36 in intramyocellular lipid accumulation, insulin sensitivity and diet-induced glucose intolerance. Within 2-3 days, diet-induced increases occurred in insulin, sarcolemmal FAT/CD36 (but not fatty acid binding protein [FABPpm] or fatty acid transporter [FATP]1 or 4), fatty acid transport and intramyocellular triacylglycerol, diacylglycerol and ceramide, independent of enzymatic changes or muscle fatty acid oxidation. Diet-induced increases in mitochondria and mitochondrial fatty acid oxidation and impairments in insulin-stimulated glucose transport and GLUT4 translocation occurred much later (≥21 days). FAT/CD36 ablation impaired insulin-stimulated fatty acid transport and lipid accumulation, improved insulin sensitivity and prevented diet-induced glucose intolerance. Increasing fatty acid oxidation in insulin-resistant muscles improved glucose transport. High-fat feeding rapidly increases intramyocellular lipids (in 2-3 days) via insulin-mediated upregulation of sarcolemmal FAT/CD36 and fatty acid

  11. The contribution of discrete-trial naming and visual recognition to rapid automatized naming deficits of dyslexic children with and without a history of language delay

    Directory of Open Access Journals (Sweden)

    Filippo eGasperini

    2014-09-01

    Full Text Available Children with Developmental Dyslexia (DD are impaired in Rapid Automatized Naming (RAN tasks, where subjects are asked to name arrays of high frequency items as quickly as possible. However the reasons why RAN speed discriminates DD from typical readers are not yet fully understood. Our study was aimed to identify some of the cognitive mechanisms underlying RAN-reading relationship by comparing one group of 32 children with DD with an age-matched control group of typical readers on a naming and a visual recognition task both using a discrete-trial methodology , in addition to a serial RAN task, all using the same stimuli (digits and colors. Results showed a significant slowness of DD children in both serial and discrete-trial naming tasks regardless of type of stimulus, but no difference between the two groups on the discrete-trial recognition task. Significant differences between DD and control participants in the RAN task disappeared when performance in the discrete-trial naming task was partialled out by covariance analysis for colors, but not for digits. The same pattern held in a subgroup of DD subjects with a history of early language delay (LD. By contrast, in a subsample of DD children without LD the RAN deficit was specific for digits and disappeared after slowness in discrete-trial naming was partialled out. Slowness in discrete-trial naming was more evident for LD than for noLD DD children. Overall, our results confirm previous evidence indicating a name-retrieval deficit as a cognitive impairment underlying RAN slowness in DD children. This deficit seems to be more marked in DD children with previous LD. Moreover, additional cognitive deficits specifically associated with serial RAN tasks have to be taken into account when explaining deficient RAN speed of these latter children. We suggest that partially different cognitive dysfunctions underpin superficially similar RAN impairments in different subgroups of DD subjects.

  12. A 13.56 MHz CMOS Active Rectifier With Switched-Offset and Compensated Biasing for Biomedical Wireless Power Transfer Systems.

    Science.gov (United States)

    Yan Lu; Wing-Hung Ki

    2014-06-01

    A full-wave active rectifier switching at 13.56 MHz with compensated bias current for a wide input range for wirelessly powered high-current biomedical implants is presented. The four diodes of a conventional passive rectifier are replaced by two cross-coupled PMOS transistors and two comparator- controlled NMOS switches to eliminate diode voltage drops such that high voltage conversion ratio and power conversion efficiency could be achieved even at low AC input amplitude |VAC|. The comparators are implemented with switched-offset biasing to compensate for the delays of active diodes and to eliminate multiple pulsing and reverse current. The proposed rectifier uses a modified CMOS peaking current source with bias current that is quasi-inversely proportional to the supply voltage to better control the reverse current over a wide AC input range (1.5 to 4 V). The rectifier was fabricated in a standard 0.35 μm CMOS N-well process with active area of 0.0651 mm(2). For the proposed rectifier measured at |VAC| = 3.0 V, the voltage conversion ratios are 0.89 and 0.93 for RL=500 Ω and 5 kΩ, respectively, and the measured power conversion efficiencies are 82.2% to 90.1% with |VAC| ranges from 1.5 to 4 V for RL=500 Ω.

  13. Deterministic and experimental study on 3-phase 6-pulse rectifiers

    Energy Technology Data Exchange (ETDEWEB)

    Mesas, J.J.; Sainz, L. [Escola Tecnica Superior d' Enginyeria Industrial de Barcelona (Spain). Dept. of Electrical Engineering; Ferrer, A. [Escola Tecnica Superior d' Enginyeria Industrial de Barcelona (Spain). Dept. of Applied Mathematics

    2009-07-01

    A 3-phase 6-pulse model with invariants was presented. The invariants were used to characterize rectifier behaviour without a DC current ripple. The current was modelled by analyzing the circuit topologies of a corresponding circuit. Supply voltages were assumed to be sinusoidal. The harmonic currents injected by the rectifiers were obtained by multiplying the normalized harmonic currents by the reference current of the load. A series of laboratory tests were then conducted to compare the measured currents of the 3-phase rectifiers with currents obtained from the invariant model. Non-linear devices were fed by sinusoidal supply voltages generated by a switching amplifier. Fourier transform was used to obtain fundamental and harmonic components. Plots were used to illustrate the invariant influence on the magnitude and phase angle of the harmonic currents. Results of the study showed that the differences between the measured currents and the invariant model are not significant. 8 refs., 7 figs.

  14. A perturbation-based model for rectifier circuits

    Directory of Open Access Journals (Sweden)

    Vipin B. Vats

    2006-01-01

    Full Text Available A perturbation-theoretic analysis of rectifier circuits is presented. The governing differential equation of the half-wave rectifier with capacitor filter is analyzed by expanding the output voltage as a Taylor series with respect to an artificially introduced parameter in the nonlinearity of the diode characteristic as is done in quantum theory. The perturbation parameter introduced in the analysis is independent of the circuit components as compared to the method presented by multiple scales. The various terms appearing in the perturbation series are then modeled in the form of an equivalent circuit. This model is subsequently used in the analysis of full-wave rectifier. Matlab simulation results are included which confirm the validity of the theoretical formulations. Perturbation analysis acts a helpful tool in analyzing time-varying systems and chaotic systems.

  15. Three-phase bridge rectifiers with freewheeling diodes

    CERN Document Server

    Hausler, M

    1973-01-01

    Freewheeling diodes are used in controlled rectifiers working in one quadrant only in order to reduce the reactive power and the d.c.- voltage ripple. In addition the freewheeling diodes allow a higher d.c.-current at low d.c.-voltages. The mean value of the freewheeling current depends on the d.c.-current, the load, and the stray-reactance of the rectifier transformer. This paper describes how the freewheeling current can be determined with these parameters. Results for some typical cases are shown in diagrams. (2 refs).

  16. Fabrication and characterization of the organic rectifying junctions by electrolysis

    Science.gov (United States)

    Karimov, Khasan; Ahmad, Zubair; Ali, Rashid; Noor, Adnan; Akmal, M.; Najeeb, M. A.; Shakoor, R. A.

    2017-08-01

    Unlike the conventional solution processable deposition techniques, in this study, we propose a novel and economical method for the fabrication of organic rectifying junctions. The solutions of the orange dye, copper phthalocyanine and NaCl were deposited on the surface-type interdigitated silver electrodes using electrolysis technique. Using the current-voltage (I-V) characteristics, the presence of rectifying behavior in the samples has been confirmed. This phenomenon, in principle, can be used for fabrication of the diodes, transistors and memory devices.

  17. Rapid 3D imaging of the lower airway by MRI in patients with congenital heart disease: A retrospective comparison of delayed volume interpolated breath-hold examination (VIBE) to turbo spin echo (TSE).

    Science.gov (United States)

    Goot, Benjamin H; Patel, Sonali; Fonseca, Brian

    2017-01-01

    When imaging the lower airway by MRI, the traditional technique turbo spin echo (TSE) results in high quality 2D images, however planning and acquisition times are lengthy. An alternative, delayed volume interpolated breath-holds examination (VIBE), is a 3D gradient echo technique that produces high spatial resolution imaging of the airway in one breath-hold. The objective of this study is to retrospectively evaluate the accuracy of lower airway measurements obtained by delayed VIBE when compared to TSE. Patients with congenital heart disease who underwent a cardiac MRI (CMR) that included a delayed VIBE sequence from 5/2008 to 9/2013 were included. Standard TSE imaging was performed and delayed VIBE was acquired 5 min after gadolinium contrast administration. Airway measurements were made on both sequences by two observers in a blinded fashion to the other observer and other technique. Intraclass correlations (ICC) were calculated to assess for agreement between both techniques and the observers. 29 studies met inclusion criteria with a mean patient age of 8.8 years (2 months to 63 years) and mean patient weight of 30.2 kg (3.5-110). All delayed VIBE and TSE sequences were found to be of diagnostic quality. Mean acquisition time was shorter for the delayed VIBE (13.1 seconds) than TSE (949.9 seconds). Overall there was very good agreement between the delayed VIBE and TSE measurements for both observers (ICC 0.78-0.94) with the exception of the distal right bronchus (ICC 0.67) The interobserver agreement was also excellent for both TSE (ICC 0.78-0.96) and VIBE (ICC 0.85-0.96). Delayed VIBE is rapid and at least as accurate as the alternative TSE imaging for assessment of the lower airway by MRI across a wide spectrum of patients. © 2016 Wiley Periodicals, Inc.

  18. Frequency Support from OWPPs connected to HVDC via Diode Rectifiers

    DEFF Research Database (Denmark)

    Saborío-Romano, Oscar; Bidadfar, Ali; Göksu, Ömer

    This paper presents a study assessing the actual capability of an offshore wind power plant (offshore WPP, OWPP) to provide frequency support (FS) to an onshore network, when connected through a high-voltage direct-current (HVDC) link having a diode rectifier (DR) offshore terminal and a voltage...

  19. A thermally switched 9 kA superconducting rectifier fluxpump

    NARCIS (Netherlands)

    ten Kate, Herman H.J.; Bunk, Paul B.; Steffens, Harry A.; van de Klundert, Louis J.M.

    1981-01-01

    The feasibility of superconducting rectifier-fluxpumps has to be demonstrated at current levels of 10 - 100 kA, where is asked for in the superconducting devices now being planned. An intensive program has been started at the low temperature division of the University of Twente to construct such

  20. THERMOELECTRIC SEMICONDUCTOR ENERGY CONVERTER TO RECTIFY THE AC VOLTAGE

    Directory of Open Access Journals (Sweden)

    T. A. Ismailov

    2014-01-01

    Full Text Available The paper discusses existing means for rectifying alternating electrical signal with inherent advantages and disadvantages. The proposed design of the AC voltage, made on the basis of the thermoelectric Converter using renewable solar energy. Made a rough calculation of this device. 

  1. Fully controlled 5-phase, 10-pulse, line commutated rectifier

    Directory of Open Access Journals (Sweden)

    Mahmoud I. Masoud

    2015-12-01

    Full Text Available The development and production of multiphase machines either generators or motors, specially five-phase, offers improved performance compared to three-phase counterpart. Five phase generators could generate power in applications such as, but not limited to, wind power generation, electric vehicles, aerospace, and oil and gas. The five-phase generator output requires converter system such as ac–dc converters. In this paper, a fully controlled 10-pulse line commutated rectifier, suitable to be engaged with wind energy applications, fed from five-phase source is introduced. A shunt active power filter (APF is used to improve power factor and supply current total harmonic distortion (THD. Compared to three-phase converters, 6-pulse or 12-pulse rectifiers, the 10-pulse rectifier engaged with 5-phase source alleviate their drawbacks such as high dc ripples and no need for electric gear or phase shifting transformer. MATLAB/SIMULINK platform is used as a simulation tool to investigate the performance of the proposed rectifier.

  2. Page 1 EFFECT OF ADMIXTURE OF SILVER ON THE RECTIFYING ...

    Indian Academy of Sciences (India)

    have undertaken to study systematically the various factors which alter the rectification of copper-cuprous oxide layers With a view that Such a systematic knowledge will enable us to understand the mechanism of the rectifying action. In this paper the influence of a Small percentage of silver impurity included in the copper ...

  3. Rectifying behaviour of spin coated pn hetero-junction

    Energy Technology Data Exchange (ETDEWEB)

    Yogamalar, N. Rajeswari; Bose, A. Chandra, E-mail: acbose@nitt.edu [Nanomaterials Laboratory, Department of Physics, National Institute of Technology, Tiruchirappalli – 620 015 (India)

    2015-06-24

    Rectifying pn hetero- junction is fabricated with an acceptor p-type organic semiconductor namely tetra- chloro dihydroxy tetra-iodo fluorescein (Rose Bengal (RB)) followed by an inorganic n-type ZnO semiconductor on indium tin oxide (ITO) substrate. The n-type ZnO films are formed by unintentional doping and doping with aluminium (Al) and yttrium (Y) donors. The surface morphology and the distribution of grains are observed from scanning electron microscopy (SEM) and atomic force microscopy (AFM). The current-voltage (I-V) characteristic of the rectifying diode is measured to characterize the junction properties. The I-V plots obtained from the hetero- junction with electric contact shows a diode characteristic different from that of an ideal behavior. The overall efficiency of the diode exhibits a greater dependency on the film crystallinity, carrier concentration, and reverse saturation current.

  4. Fully controlled 5-phase, 10-pulse, line commutated rectifier

    OpenAIRE

    Masoud, Mahmoud I.

    2015-01-01

    The development and production of multiphase machines either generators or motors, specially five-phase, offers improved performance compared to three-phase counterpart. Five phase generators could generate power in applications such as, but not limited to, wind power generation, electric vehicles, aerospace, and oil and gas. The five-phase generator output requires converter system such as ac–dc converters. In this paper, a fully controlled 10-pulse line commutated rectifier, suitable to be ...

  5. Tunable Radiative Thermal Rectifiers : Toward Thermal Logical Circuits

    OpenAIRE

    Nefzaoui, Elyes; Ezzahri, Younès; Joulain, Karl; Drevillon, Jérémie

    2015-01-01

    International audience; Thermal rectification can be defined as an asymmetry in the heat flux when the temperature difference between two interacting thermal reservoirs is reversed. We present a thermal rectifier concept based on far-field radiative heat transfer. The device is composed of two opaque thermal baths 1 and 2 at temperatures T 1 and T 2 respectively and exchanging heat through thermal radiation. The two interacting bodies are made of spectrally selective photonic structures with ...

  6. Fast switching wideband rectifying circuit for future RF energy harvesting

    Science.gov (United States)

    Asmeida, Akrem; Mustam, Saizalmursidi Md; Abidin, Z. Z.; Ashyap, A. Y. I.

    2017-09-01

    This paper presents the design and simulation of fast switching microwave rectifying circuit for ultra wideband patch antenna over a dual-frequency band (1.8 GHz for GSM and 2.4 GHz for ISM band). This band was chosen due to its high signal availability in the surrounding environment. New rectifying circuit topology with pair-matching trunks is designed using Advanced Design System (ADS) software. These trunks are interfaced with power divider to achieve good bandwidth, fast switching and high efficiency. The power divider acts as a good isolator between the trunks and its straightforward design structure makes it a good choice for a single feed UWB antenna. The simulated results demonstrate that the maximum output voltage is 2.13 V with an input power of -5 dBm. Moreover, the rectifier offers maximum efficiency of 86% for the input power of -5 dBm at given band, which could easily power up wireless sensor networks (WSN) and other small devices sufficiently.

  7. Physiological and molecular characterization of an IRK-type inward rectifier K+ channel in a tumour mast cell line.

    Science.gov (United States)

    Wischmeyer, E; Lentes, K U; Karschin, A

    1995-04-01

    The basophilic leucaemia cell line RBL-2H3 exhibits a robust inwardly rectifying potassium current, IKIR, which is likely to be modulated by G proteins. We examined the physiological and molecular properties of this KIR conductance to define the nature of the underlying channel species. The macroscopic conductance revealed characteristics typical of classical K+ inward rectifiers of the IRK type. Channel gating was rapid, first order (tau approximately 1 ms at -100 mV) and steeply voltage dependent. Both activation potential and slope conductance were dependent on extracellular K+ concentration ([K+]o) and inward rectification persisted in the absence of internal Mg2+. The current was susceptible to a concentration- and voltage-dependent block by extracellular Na+, Cs+ and Ba2+. Initial IKIR whole-cell amplitudes as well as current rundown were dependent on the presence of 1 mM internal ATP. Perfusion of intracellular guanosine 5'-Q-(3-thiotriphosphate) (GTP[gamma S]) suppressed IKIR with an average half-time of decline of approximately 400 s. It was demonstrated that the dominant IRK-type 25 pS conductance channel was indeed suppressed by 100 microM preloaded GTP[gamma S]. Reverse transcriptase-polymerase chain reactions (RT-PCR) with RBL cell poly(A)+ RNA identified a full length K+ inward rectifier with 94% base pair homology to the recently cloned mouse IRK1 channel. It is concluded that RBL cells express a classical voltage-dependent IRK-type K+ inward rectifier RBL-IRK1 which is negatively controlled by G proteins.

  8. Accumulation of slowly activating delayed rectifier potassium current (IKs) in canine ventricular myocytes

    DEFF Research Database (Denmark)

    Stengl, Milan; Volders, Paul G A; Thomsen, Morten Bækgaard

    2003-01-01

    the deactivation is much faster, is still unclear. In this study the conditions under which accumulation occurs in canine ventricular myocytes were studied with regard to its physiological relevance in controlling action potential duration (APD). At baseline, square pulse voltage clamp experiments revealed...... that the accumulation of canine IKs could occur, but only at rather short interpulse intervals (... in the presence of isoproterenol. Block of IKs, however, led to a reverse rate-dependent prolongation of APD indicating that IKs does not have a dominant role at short cycle lengths....

  9. Combinational logic for generating gate drive signals for phase control rectifiers

    Science.gov (United States)

    Dolland, C. R.; Trimble, D. W. (Inventor)

    1982-01-01

    Control signals for phase-delay rectifiers, which require a variable firing angle that ranges from 0 deg to 180 deg, are derived from line-to-line 3-phase signals and both positive and negative firing angle control signals which are generated by comparing current command and actual current. Line-to-line phases are transformed into line-to-neutral phases and integrated to produce 90 deg phase delayed signals that are inverted to produce three cosine signals, such that for each its maximum occurs at the intersection of positive half cycles of the other two phases which are inputs to other inverters. At the same time, both positive and negative (inverted) phase sync signals are generated for each phase by comparing each with the next and producing a square wave when it is greater. Ramp, sync and firing angle controls signals are than used in combinational logic to generate the gate firing control signals SCR gate drives which fire SCR devices in a bridge circuit.

  10. Reducing patient delay in Acute Coronary Syndrome (RAPiD): research protocol for a web-based randomized controlled trial examining the effect of a behaviour change intervention.

    Science.gov (United States)

    Farquharson, Barbara; Johnston, Marie; Smith, Karen; Williams, Brian; Treweek, Shaun; Dombrowski, Stephan U; Dougall, Nadine; Abhyankar, Purva; Grindle, Mark

    2017-05-01

    To evaluate the efficacy of a behaviour change technique-based intervention and compare two possible modes of delivery (text + visual and text-only) with usual care. Patient delay prevents many people from achieving optimal benefit of time-dependent treatments for acute coronary syndrome. Reducing delay would reduce mortality and morbidity, but interventions to change behaviour have had mixed results. Systematic inclusion of behaviour change techniques or a visual mode of delivery might improve the efficacy of interventions. A three-arm web-based, parallel randomized controlled trial of a theory-based intervention. The intervention comprises 12 behaviour change techniques systematically identified following systematic review and a consensus exercise undertaken with behaviour change experts. We aim to recruit n = 177 participants who have experienced acute coronary syndrome in the previous 6 months from a National Health Service Hospital. Consenting participants will be randomly allocated in equal numbers to one of three study groups: i) usual care, ii) usual care plus text-only behaviour change technique-based intervention or iii) usual care plus text + visual behaviour change technique-based intervention. The primary outcome will be the change in intention to phone an ambulance immediately with symptoms of acute coronary syndrome ≥15-minute duration, assessed using two randomized series of eight scenarios representing varied symptoms before and after delivery of the interventions or control condition (usual care). Funding granted January 2014. Positive results changing intentions would lead to a randomized controlled trial of the behaviour change intervention in clinical practice, assessing patient delay in the event of actual symptoms. Registered at ClinicalTrials.gov: NCT02820103. © 2016 John Wiley & Sons Ltd.

  11. RF rectifiers for EM power harvesting in a Deep Brain Stimulating device.

    Science.gov (United States)

    Hosain, Md Kamal; Kouzani, Abbas Z; Tye, Susannah; Kaynak, Akif; Berk, Michael

    2015-03-01

    A passive deep brain stimulation (DBS) device can be equipped with a rectenna, consisting of an antenna and a rectifier, to harvest energy from electromagnetic fields for its operation. This paper presents optimization of radio frequency rectifier circuits for wireless energy harvesting in a passive head-mountable DBS device. The aim is to achieve a compact size, high conversion efficiency, and high output voltage rectifier. Four different rectifiers based on the Delon doubler, Greinacher voltage tripler, Delon voltage quadrupler, and 2-stage charge pumped architectures are designed, simulated, fabricated, and evaluated. The design and simulation are conducted using Agilent Genesys at operating frequency of 915 MHz. A dielectric substrate of FR-4 with thickness of 1.6 mm, and surface mount devices (SMD) components are used to fabricate the designed rectifiers. The performance of the fabricated rectifiers is evaluated using a 915 MHz radio frequency (RF) energy source. The maximum measured conversion efficiency of the Delon doubler, Greinacher tripler, Delon quadrupler, and 2-stage charge pumped rectifiers are 78, 75, 73, and 76 % at -5 dBm input power and for load resistances of 5-15 kΩ. The conversion efficiency of the rectifiers decreases significantly with the increase in the input power level. The Delon doubler rectifier provides the highest efficiency at both -5 and 5 dBm input power levels, whereas the Delon quadrupler rectifier gives the lowest efficiency for the same inputs. By considering both efficiency and DC output voltage, the charge pump rectifier outperforms the other three rectifiers. Accordingly, the optimised 2-stage charge pumped rectifier is used together with an antenna to harvest energy in our DBS device.

  12. Rectifying calibration error of Goldmann applanation tonometer is easy!

    Directory of Open Access Journals (Sweden)

    Nikhil S Choudhari

    2014-01-01

    Full Text Available Purpose: Goldmann applanation tonometer (GAT is the current Gold standard tonometer. However, its calibration error is common and can go unnoticed in clinics. Its company repair has limitations. The purpose of this report is to describe a self-taught technique of rectifying calibration error of GAT. Materials and Methods: Twenty-nine slit-lamp-mounted Haag-Streit Goldmann tonometers (Model AT 900 C/M; Haag-Streit, Switzerland were included in this cross-sectional interventional pilot study. The technique of rectification of calibration error of the tonometer involved cleaning and lubrication of the instrument followed by alignment of weights when lubrication alone didn′t suffice. We followed the South East Asia Glaucoma Interest Group′s definition of calibration error tolerance (acceptable GAT calibration error within ±2, ±3 and ±4 mm Hg at the 0, 20 and 60-mm Hg testing levels, respectively. Results: Twelve out of 29 (41.3% GATs were out of calibration. The range of positive and negative calibration error at the clinically most important 20-mm Hg testing level was 0.5 to 20 mm Hg and -0.5 to -18 mm Hg, respectively. Cleaning and lubrication alone sufficed to rectify calibration error of 11 (91.6% faulty instruments. Only one (8.3% faulty GAT required alignment of the counter-weight. Conclusions: Rectification of calibration error of GAT is possible in-house. Cleaning and lubrication of GAT can be carried out even by eye care professionals and may suffice to rectify calibration error in the majority of faulty instruments. Such an exercise may drastically reduce the downtime of the Gold standard tonometer.

  13. Hyperventilation assists proarrhythmia development during delayed repolarization in clofilium-treated, anaesthetized, mechanically ventilated rabbits.

    Science.gov (United States)

    Papp, H; Sarusi, A; Farkas, A S; Takacs, H; Kui, P; Vincze, D; Ivany, E; Varro, A; Papp, J G; Forster, T; Farkas, A

    2016-10-01

    Hyperventilation reduces partial pressure of CO2 (PCO2) in the blood, which results in hypokalaemia. Hypokalaemia helps the development of the life-threatening torsades de pointes type ventricular arrhythmia (TdP) evoked by repolarization delaying drugs. This implies that hyperventilation may assist the development of proarrhythmic events. Therefore, this study experimentally investigated the effect of hyperventilation on proarrhythmia development during delayed repolarization. Phenylephrine (an α1-adrenoceptor agonist) and clofilium (as a representative repolarization delaying agent inhibiting the rapid component of the delayed rectifier potassium current, IKr) were administered intravenously to pentobarbital-anaesthetized, mechanically ventilated, open chest rabbits. ECG was recorded, and the onset times and incidences of the arrhythmias were determined. Serum K+, pH and PCO2 were measured in arterial blood samples. Clofilium prolonged the rate corrected QT interval. TdP occurred in 15 animals (TdP+ group), and did not occur in 14 animals (TdP- group). We found a strong, positive, linear correlation between serum K+ and PCO2. There was no relationship between the occurrence of TdP and the baseline K+ and PCO2 values. However, a positive, linear correlation was found between the onset time of the first arrhythmias and the K+ and PCO2 values. The regression lines describing the relationship between PCO2 and onset time of first arrhythmias were parallel in the TdP+ and TdP- groups, but the same PCO2 resulted in earlier arrhythmia onset in the TdP+ group than in the TdP- group. We conclude that hyperventilation and hypocapnia with the resultant hypokalaemia assist the multifactorial process of proarrhythmia development during delayed repolarization. This implies that PCO2 and serum K+ should be controlled tightly during mechanical ventilation in experimental investigations and clinical settings when repolarization-delaying drugs are applied.

  14. The rectifying performance of the multibiphenyl with different end groups: A density functional study

    Science.gov (United States)

    Deng, Xiaoqing; Zhang, Zhenhua; Zhou, Jicheng; Tang, Guiping

    2011-03-01

    We investigated the rectifying properties of the multibiphenyl connected to two Au electrodes based on the nonequilibrium Green's function method combined with the density functional theory. It has been found that the number of benzenes and the type of end groups have distinct influences on rectifying performance of such devices. For the four (five)-benzene system connected with Au electrodes by S-Au bond, we can observe the rectifying performance. While for the six-benzene system, the rectifying behavior is more obvious. When the left end benzene is replaced by pyrimidine, the rectifying effect is weakened. When this substitute is pyridine, however, the rectifying behavior changes clearly as compared with the previous two cases. The detailed analysis demonstrates that the highest occupied molecular orbital resonance changing with the applied bias contributes to the obvious asymmetry of current-voltage characteristics.

  15. The Outwardly Rectifying Current of Layer 5 Neocortical Neurons that was Originally Identified as "Non-Specific Cationic" Is Essentially a Potassium Current.

    Directory of Open Access Journals (Sweden)

    Omer Revah

    Full Text Available In whole-cell patch clamp recordings from layer 5 neocortical neurons, blockade of voltage gated sodium and calcium channels leaves a cesium current that is outward rectifying. This current was originally identified as a "non-specific cationic current", and subsequently it was hypothesized that it is mediated by TRP channels. In order to test this hypothesis, we used fluorescence imaging of intracellular sodium and calcium indicators, and found no evidence to suggest that it is associated with influx of either of these ions to the cell body or dendrites. Moreover, the current is still prominent in neurons from TRPC1-/- and TRPC5-/- mice. The effects on the current of various blocking agents, and especially its sensitivity to intracellular tetraethylammonium, suggest that it is not a non-specific cationic current, but rather that it is generated by cesium-permeable delayed rectifier potassium channels.

  16. Study of 18-Pulse Rectifier Utilizing Hexagon Connected 3-Phase to 9-Phase Transformer

    Directory of Open Access Journals (Sweden)

    Ahmad Saudi Samosir

    2008-04-01

    Full Text Available The 18-pulse converter, using Y or -connected differential autotransformer, is very interesting since it allows natural high power factor correction. The lowest input current harmonic components are the 17th and 19th. The Transformer is designed to feed three six-pulse bridge rectifiers displaced in phase by 200. This paper present a high power factor three-phase rectifier bases on 3-phase to 9-phase transformer and 18-pulse rectifier. The 9-phase polygon-connected transformer followed by 18-pulse diode rectifiers ensures the fundamental concept of natural power factor correction. Simulation results to verify the proposed concept are shown in this paper.

  17. 2015 NOAA Ortho-rectified Mosaic of Ortho-rectified Below Mean High Water Color Mosaic of Jacksonville, Florida: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  18. Delayed Puberty

    DEFF Research Database (Denmark)

    Kolby, Nanna; Busch, Alexander Siegfried; Juul, Anders

    2017-01-01

    Delayed puberty can be a source of great concern and anxiety, although it usually is caused by a self-limiting variant of the normal physiological timing named constitutional delay of growth and puberty (CDGP). Delayed puberty can, however, also be the first presentation of a permanent condition...... of diagnostic evaluation today remain in distinguishing the benign CDGP from underlying pathological causes such as hypogonadotropic hypogonadism (HH) and hypergonadotropic hypogonadism. Several techniques have been investigated for this purpose and are reviewed in this chapter; however, no single test is yet...

  19. On fully superconducting rectifiers and fluxpumps. A review. Part 2: Commutation modes, characteristics and switches

    NARCIS (Netherlands)

    van de Klundert, L.J.M.; ten Kate, Herman H.J.

    1981-01-01

    This paper forms the second part of the review. Full and half wave superconducting transformer rectifiers are analysed. Modes of operation and loss mechanisms are detailed and a comparison between the behaviour of dynamos and rectifiers is presented. Investigations carried out to date still leave

  20. PERFORMANCE EVALUATION OF THREE PHASE SCALAR CONTROLLED PWM RECTIFIER USING DIFFERENT CARRIER AND MODULATING SIGNAL

    Directory of Open Access Journals (Sweden)

    J. CHELLADURAI

    2015-04-01

    Full Text Available Power quality problems caused by significant increase of non-linear loads initiated intensive research in high power factor converters. Most of the modern power electronic systems like variable speed drives, DC power supplies and battery charging systems uses uncontrolled diode bridge rectifier. The uncontrolled rectifier system injects lot of harmonics in to the AC supply system there by reducing the power factor to less than unity. Single stage PWM rectifier is the novel solution to eliminate the harmonics and to improve the input power factor. In this paper, a scalar controlled PWM rectifier is modeled and the system is compared with the conventional bridge rectifier with and without filter.The major advantages of using this technique are less intensive computational control and sensor less input voltage operation. The PWM rectifier system is investigated using the different carrier and modulating signal. The scalar control technique is used to control the boost rectifier output voltage and input power factor. The performance of the rectifier with different carrier and modulating techniques were compared with respect to the Total Harmonic Distortion (THD in source current. Simulation results demonstrate the effectiveness of the modified modulating signal and triangular carrier signal for effectively reducing the source current THD.

  1. 27 CFR 1.21 - Domestic producers, rectifiers, blenders, and warehousemen.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Domestic producers, rectifiers, blenders, and warehousemen. 1.21 Section 1.21 Alcohol, Tobacco Products and Firearms ALCOHOL AND... BOTTLING OF DISTILLED SPIRITS Basic Permits When Required § 1.21 Domestic producers, rectifiers, blenders...

  2. G-protein-coupled inward rectifier potassium current contributes to ventricular repolarization

    DEFF Research Database (Denmark)

    Liang, Bo; Nissen, Jakob D; Laursen, Morten

    2014-01-01

    The purpose of this study was to investigate the functional role of G-protein-coupled inward rectifier potassium (GIRK) channels in the cardiac ventricle.......The purpose of this study was to investigate the functional role of G-protein-coupled inward rectifier potassium (GIRK) channels in the cardiac ventricle....

  3. Delayed growth

    Science.gov (United States)

    ... 4 years Developmental milestones record - 5 years Causes Constitutional growth delay refers to children who are small ... nutrition expert who can help you choose the right foods to offer your child. What to Expect ...

  4. Delayed Ejaculation

    Science.gov (United States)

    ... bladder rather than out of the penis Psychological causes of delayed ejaculation include: Depression, anxiety or other mental health conditions Relationship problems due to stress, poor communication or other concerns ...

  5. Delayed Ejaculation

    Science.gov (United States)

    ... of stress Delayed ejaculation Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  6. Rapid breakdown of microvascular barriers and subsequent hemorrhagic transformation after delayed recombinant tissue plasminogen activator treatment in a rat embolic stroke model.

    Science.gov (United States)

    Dijkhuizen, Rick M; Asahi, Minoru; Wu, Ona; Rosen, Bruce R; Lo, Eng H

    2002-08-01

    Thrombolytic therapy with recombinant tissue plasminogen activator (rtPA) after stroke increases risk of hemorrhagic transformation, particularly in areas with blood-brain barrier leakage. Our aim was to characterize acute effects of rtPA administration on the integrity of microvascular barriers. Stroke was induced in spontaneously hypertensive rats by unilateral embolic middle cerebral artery occlusion. Six hours after stroke, rtPA was intravenously administered (n=10). Controls received saline (n=4). Extravasation of the large-diameter contrast agent monocrystalline iron oxide nanocolloid (MION) was assessed with susceptibility contrast-enhanced MRI during rtPA injection. In addition, we performed perfusion MRI and diffusion-weighted MRI. After MRI, 2 hours after rtPA treatment, intracerebral hemorrhage was quantified with a spectrophotometric hemoglobin assay. Late rtPA treatment resulted in increased hemorrhage volume (8.4+/-1.7 versus 2.9+/-0.9 micro L in controls; Pcerebral blood flow index was 22.8+/-19.7% [of contralateral] at 0.5 hours before and 22.4+/-18.0% at 1 hour after rtPA administration). The DeltaR2* changes during rtPA delivery in MION-injected animals indicate extravasation of MION, which reflects increased permeability of the blood-brain barrier. This implies that late rtPA treatment rapidly aggravates early ischemia-induced damage to microvascular barriers, thereby enhancing hemorrhagic transformation.

  7. Method for rectifying image deviation based on perspective transformation

    Science.gov (United States)

    Li, Xin; Li, Shengrong; Bai, Wei; Cui, Xiaoxiao; Yang, Guoqing; Zhou, Hao; Zhang, Chuanyou

    2017-09-01

    A new method for rectifying image deviation of circular instrument based on perspective transformation is presented in the paper, and the correction of circular instrument image in substation environment is realized. First of all, the digital image processing technology is used to pre-process the site image. Secondly, Canny operator is used for edge detection. According to the edge feature points, the equipment area is detected and the regional parameters can be computed. Then the perspective transformation is used to correct the image, and the positive image of the circular instrument image is obtained. Finally, the corrected tilt image is done by the rotation operation. Experimental results show that the algorithm can realize image rectification, which is simple with fast speed and high precision. The proposed method is helpful for the further recognition.

  8. High performance direct instantaneous power control of PWM rectifiers

    Energy Technology Data Exchange (ETDEWEB)

    Monfared, Mohammad, E-mail: m.monfared@aut.ac.i [Dept. of Electrical Eng., Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Rastegar, Hassan, E-mail: rastegar@aut.ac.i [Dept. of Electrical Eng., Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Kojabadi, Hossein Madadi, E-mail: hmadadi64@yahoo.c [Dept. of Electrical Eng., Sahand University of Technology, Tabriz (Iran, Islamic Republic of)

    2010-05-15

    This paper presents a new direct instantaneous power control (DPC) strategy for active rectifiers. In this novel scheme the PWM modulator has been utilized instead of the hysteresis comparators and switching table. The required converter voltage in each sampling period is directly calculated based on the reference and measured values of powers, system parameters, and the measured voltage of the AC source through simple equations which are wisely compensated for variations of the grid voltage during a sampling period. Then, the PWM generator generates the switching pulses for the voltage source converter. It is shown that the proposed DPC-PWM exhibits several features, such as a simple algorithm, constant switching frequency, robust to sampling frequency changes, robust to inductance values mismatch, and particularly it provides low sampling frequency. Extensive simulation and experimental results have proven the excellent performance and verify the validity and effectiveness of the proposed instantaneous power control scheme.

  9. Self-Biased Differential Rectifier with Enhanced Dynamic Range for Wireless Powering

    KAUST Repository

    Ouda, Mahmoud H.

    2016-08-29

    A self-biased, cross-coupled, differential rectifier is proposed with enhanced power-conversion efficiency over an extended range of input power. A prototype is designed for UHF 433MHz RF power-harvesting applications and is implemented using 0.18μm CMOS technology. The proposed rectifier architecture is compared to the conventional cross-coupled rectifier. It demonstrates an improvement of more than 40% in the rectifier power conversion efficiency (PCE) and an input power range extension of more than 50% relative to the conventional crosscoupled rectifier. A sensitivity of -15.2dBm (30μW) input power for 1V output voltage and a peak power-conversion efficiency of 65% are achieved for a 50kω load. © 2004-2012 IEEE.

  10. MPC-SVM method for Vienna rectifier with PMSG used in Wind Turbine Systems

    DEFF Research Database (Denmark)

    Lee, June-Seok; Bak, Yeongsu; Lee, Kyo-Beum

    2016-01-01

    ) method for the Vienna rectifier used in WTS with a Permanent Magnet Synchronous Generator (PMSG). The proposed MPC method considers the feasible eight-voltage vectors of the Vienna rectifier. In addition, the voltage vectors, which are the center voltage vectors of two feasible adjacent voltage vectors......Using a Vienna rectifier as the machine-side rectifier of back-to-back converter is advantageous in terms of size and cost compared to three-level topologies and for this reason, the Vienna rectifier has been used in Wind Turbine Systems (WTS). This paper proposes a Model Predictive Control (MPC......, are taken into consideration to improve the performance of the MPC method. The optimized voltage vector for the ripple minimization of PMSG currents is determined by cost function. Then, the neutral-point voltage unbalancing problem is considered for selecting the final switching set, which is generated...

  11. Input Power Quality Improvement in Switched Reluctance Motor Drive using Minnesota Rectifier

    Science.gov (United States)

    Singh, B.; Rajesh, M.

    2013-09-01

    This paper deals with an input power quality improvement in a midpoint converter based switched reluctance motor (SRM) drive at ac mains using Minnesota rectifier. Normally a midpoint converter is used as a power converter for SRM drive. Conventionally three phase ac mains fed bridge rectifier is used as a dc source to feed this power converter which produces high content of harmonics at ac mains with a very low power factor. The proposed Minnesota rectifier with a midpoint converter fed SRM drive improves the power factor at ac mains with low current harmonics. This method provides constant dc link voltage and balanced capacitor voltages of the midpoint converter. The Minnesota rectifier fed SRM drive is modelled and its performance is simulated in Matlab/Simulink environment. The performance of Minnesota rectifier is compared with a conventional bridge topology for SRM drive to demonstrate improved power quality at ac mains.

  12. Can arousing feedback rectify lapses in driving? Prediction from EEG power spectra

    Science.gov (United States)

    Lin, Chin-Teng; Huang, Kuan-Chih; Chuang, Chun-Hsiang; Ko, Li-Wei; Jung, Tzyy-Ping

    2013-10-01

    Objective. This study explores the neurophysiological changes, measured using an electroencephalogram (EEG), in response to an arousing warning signal delivered to drowsy drivers, and predicts the efficacy of the feedback based on changes in the EEG. Approach. Eleven healthy subjects participated in sustained-attention driving experiments. The driving task required participants to maintain their cruising position and compensate for randomly induced lane deviations using the steering wheel, while their EEG and driving performance were continuously monitored. The arousing warning signal was delivered to participants who experienced momentary behavioral lapses, failing to respond rapidly to lane-departure events (specifically the reaction time exceeded three times the alert reaction time). Main results. The results of our previous studies revealed that arousing feedback immediately reversed deteriorating driving performance, which was accompanied by concurrent EEG theta- and alpha-power suppression in the bilateral occipital areas. This study further proposes a feedback efficacy assessment system to accurately estimate the efficacy of arousing warning signals delivered to drowsy participants by monitoring the changes in their EEG power spectra immediately thereafter. The classification accuracy was up 77.8% for determining the need for triggering additional warning signals. Significance. The findings of this study, in conjunction with previous studies on EEG correlates of behavioral lapses, might lead to a practical closed-loop system to predict, monitor and rectify behavioral lapses of human operators in attention-critical settings.

  13. Auto-tuning of digitally controlled single-phase low harmonic rectifiers and inverters

    Science.gov (United States)

    Moon, Sungwoo

    2011-12-01

    Effective power transfer has been one of the main issues in power electronics. In particular, low-harmonic alternating current (AC) shaping is required by various regulations at the interface between AC power grid and direct current (DC) loads or sources. In order to meet rapidly evolving efficiency standards and environmental concerns, intelligent AC current shaping strategies are required. In the power converter stage, however, inherent uncertainties caused by passive component tolerances and changes in operating conditions may impair the control loop stability, while mis-detection of operating modes over wide load range aggravates the situation further. This thesis introduces an auto-tuning technique in digitally controlled single-phase AC-DC rectifiers and DC-AC inverters. The approach is capable of precise on-line estimation of the power stage passive component values. The control loop compensator parameters are modified adaptively to maintain the nominal stability margins and control loop bandwidth based on the estimated component values. Furthermore, accurate continuous conduction mode (CCM) and discontinuous conduction mode (DCM) boundary detection is achieved as a result of the tuning process, without the need for additional circuitry. Implementation of the tuning approach is relatively simple. The proposed tuning approach is verified on experimental AC-DC and DC-AC prototypes.

  14. Graphene ballistic nano-rectifier with very high responsivity.

    Science.gov (United States)

    Auton, Gregory; Zhang, Jiawei; Kumar, Roshan Krishna; Wang, Hanbin; Zhang, Xijian; Wang, Qingpu; Hill, Ernie; Song, Aimin

    2016-05-31

    Although graphene has the longest mean free path of carriers of any known electronic material, very few novel devices have been reported to harness this extraordinary property. Here we demonstrate a ballistic nano-rectifier fabricated by creating an asymmetric cross-junction in single-layer graphene sandwiched between boron nitride flakes. A mobility ∼200,000 cm(2) V(-1) s(-1) is achieved at room temperature, well beyond that required for ballistic transport. This enables a voltage responsivity as high as 23,000 mV mW(-1) with a low-frequency input signal. Taking advantage of the output channels being orthogonal to the input terminals, the noise is found to be not strongly influenced by the input. Hence, the corresponding noise-equivalent power is as low as 0.64 pW Hz(-1/2). Such performance is even comparable to superconducting bolometers, which however need to operate at cryogenic temperatures. Furthermore, output oscillations are observed at low temperatures, the period of which agrees with the lateral size quantization.

  15. Terahertz Detection and Imaging Using Graphene Ballistic Rectifiers.

    Science.gov (United States)

    Auton, Gregory; But, Dmytro B; Zhang, Jiawei; Hill, Ernie; Coquillat, Dominique; Consejo, Christophe; Nouvel, Philippe; Knap, Wojciech; Varani, Luca; Teppe, Frederic; Torres, Jeremie; Song, Aimin

    2017-11-08

    A graphene ballistic rectifier is used in conjunction with an antenna to demonstrate a rectenna as a terahertz (THz) detector. A small-area (<1 μm 2 ) local gate is used to adjust the Fermi level in the device to optimize the output while minimizing the impact on the cutoff frequency. The device operates in both n- and p-type transport regimes and shows a peak extrinsic responsivity of 764 V/W and a corresponding noise equivalent power of 34 pW Hz -1/2 at room temperature with no indications of a cutoff frequency up to 0.45 THz. The device also demonstrates a linear response for more than 3 orders of magnitude of input power due to its zero threshold voltage, quadratic current-voltage characteristics and high saturation current. Finally, the device is used to take an image of an optically opaque object at 0.685 THz, demonstrating potential in both medical and security imaging applications.

  16. Rectifying thermal fluctuations: Minimal pumping and Maxwell's demon

    Science.gov (United States)

    Mandal, Dibyendu

    Molecular complexes with movable components form the basis of nanoscale machines. Their inherent stochastic nature makes it a challenge to generate any controllable movement. Rather than fighting these fluctuations, one can utilize them by the periodic modulation of system parameters, or stochastic pumping. For the no-pumping theorem (NPT), which establishes minimal conditions for directed pumping, we present a simplified proof using an elementary graph theoretical construction. Motivated by recent experiments, we propose a new class of "hybrid" models combining elements of both the purely discrete and purely continuous descriptions prevalent in the field. We formulate the NPT in this hybrid framework to give a detailed justification of the original experiment observation. We also present an extension of the NPT to open stochastic systems. Next we consider the paradox of "Maxwell's demon," an imaginary intelligent being that rectifies thermal fluctuations in a manner that seems to violate the second law of thermodynamics. We present two exactly solvable, autonomous models that can reproduce the actions of the demon. Of necessity, both of these models write information on a memory device as part of their operation. By exposing their explicit, transparent mechanisms, our models offer simple paradigms to investigate the autonomous rectification of thermal fluctuations and the thermodynamics of information processing.

  17. Generalized space vector control for current source inverters and rectifiers

    Directory of Open Access Journals (Sweden)

    Roseline J. Anitha

    2016-06-01

    Full Text Available Current source inverters (CSI is one of the widely used converter topology in medium voltage drive applications due to its simplicity, motor friendly waveforms and reliable short circuit protection. The current source inverters are usually fed by controlled current source rectifiers (CSR with a large inductor to provide a constant supply current. A generalized control applicable for both CSI and CSR and their extension namely current source multilevel inverters (CSMLI are dealt in this paper. As space vector pulse width modulation (SVPWM features the advantages of flexible control, faster dynamic response, better DC utilization and easy digital implementation it is considered for this work. This paper generalizes SVPWM that could be applied for CSI, CSR and CSMLI. The intense computation involved in framing a generalized space vector control are discussed in detail. The algorithm includes determination of band, region, subregions and vectors. The algorithm is validated by simulation using MATLAB /SIMULINK for CSR 5, 7, 13 level CSMLI and for CSR fed CSI.

  18. Delayed perceptual awareness in rapid perceptual decisions.

    Directory of Open Access Journals (Sweden)

    Regina Gregori-Grgič

    Full Text Available The flourishing of studies on the neural correlates of decision-making calls for an appraisal of the relation between perceptual decisions and conscious perception. By exploiting the long integration time of noisy motion stimuli, and by forcing human observers to make difficult speeded decisions--sometimes a blind guess--about stimulus direction, we traced the temporal buildup of motion discrimination capability and perceptual awareness, as assessed trial by trial through direct rating. We found that both increased gradually with motion coherence and viewing time, but discrimination was systematically leading awareness, reaching a plateau much earlier. Sensitivity and criterion changes contributed jointly to the slow buildup of perceptual awareness. It made no difference whether motion discrimination was accomplished by saccades or verbal responses. These findings suggest that perceptual awareness emerges on the top of a developing or even mature perceptual decision. We argue that the middle temporal (MT cortical region does not confer us the full phenomenic depth of motion perception, although it may represent a precursor stage in building our subjective sense of visual motion.

  19. Delayed Puberty

    DEFF Research Database (Denmark)

    Kolby, Nanna; Busch, Alexander Siegfried; Juul, Anders

    2017-01-01

    or a symptom of an underlying disease. The diagnosis delayed puberty is made if there are no signs of puberty at an age corresponding to 2 SD above the population mean age at pubertal onset, often translated into 14 years in boys. Delayed puberty among boys is a frequent presentation in pediatrics....... The underlying reasons for the large variation in the age at pubertal onset are not fully established; however, nutritional status and socioeconomic and environmental factors are known to be influencing, and a significant amount of influencing genetic factors have also been identified. The challenges...... of diagnostic evaluation today remain in distinguishing the benign CDGP from underlying pathological causes such as hypogonadotropic hypogonadism (HH) and hypergonadotropic hypogonadism. Several techniques have been investigated for this purpose and are reviewed in this chapter; however, no single test is yet...

  20. 2014 NOAA Ortho-rectified Color Mosaic of Conneaut, Ohio: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  1. 2012 NOAA Ortho-rectified Color Mosaic of Oregon: Lake Umatilla to Clarkson

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  2. 2010 NOAA Ortho-rectified Mosaic from Color Aerial Imagery of BEAUMONT, ORANGE, PORT AUTHUR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative of BEAUMONT, ORANGE,...

  3. 2012 NOAA Ortho-rectified Near-Infrared MLLW Mosaic of Alabama: Eastern Mississippi Sound

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  4. 2009 NOAA Near-Infrared Ortho-rectified Mosaic of Brunswick, Georgia (NODC Accession 0092435)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  5. 2016 NOAA NGS Ortho-rectified Color Mosaic of New Orleans and South Louisiana, Louisiana

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  6. 2016 NOAA NGS Ortho-rectified Color Mosaic of Nome, Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  7. 2011 NOAA Ortho-rectified Color Mosaic of Northeast Point to Murphy Island, South Carolina

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  8. 2013 NOAA Ortho-rectified Color Mosaic of Florida: Lake Okeechobee

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  9. 2016 NOAA NGS Ortho-rectified Color Mosaic of Muskegon, Grand Haven,and Holland, Michigan

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  10. 2012 NOAA Color Ortho-rectified Mosaic of Trinity Bay, Texas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  11. 2012 NOAA Ortho-rectified Mosaic of Texas: Trinity Bay, Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  12. 2012 NOAA Ortho-rectified Color MLLW Mosaic of Pescadero Point to Bodega Bay, California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  13. 2016 NOAA NGS Ortho-rectified Color Mosaic of Whittier, Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  14. 2012 NOAA Color Ortho-rectified Mosaic of Corpus Christi to Saint Charles Bay, Texas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  15. 2013 NOAA Ortho-rectified Near Infrared Mosaic of Florida: Lake Okeechobee

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  16. 2011 NOAA Ortho-rectified Mosaic of Brownsville Ship Channel, Texas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  17. 2014 NOAA Ortho-rectified Mosaic of Delaware Coastline: Hurricane Sandy Impact Area

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles at 0.10m GSD. This data set was created for NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative in the...

  18. 2016 NOAA NGS Ortho-rectified Oblique Imagery of the Great Lakes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  19. 2014 NOAA Ortho-rectified Mosaic of Hurricane Sandy Coastal Impact Area

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles at 0.35m GSD created for NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative in Hurricane Sandy coastal...

  20. 2017 NOAA NGS Ortho-rectified Color Mosaic of Houston Ship Channel, Texas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  1. 2012 NOAA Ortho-rectified Color MLLW Mosaic of Alabama: Eastern Mississippi Sound

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  2. 2011 NOAA Ortho-rectified Mosaic of Anguilla Harbor, St. Croix, U.S. Virgin Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  3. 2011 NOAA Near Infrared Ortho-rectified Mosaic of New Jersey: Delaware Bay - New Jersey Shoreline

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  4. 2010 NOAA Ortho-rectified Mosaic of Louisiana: Mississippi River - Baton Rouge to Southwest Pass

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  5. 2009 NOAA Near-Infrared Ortho-rectified Mosaic of Brunswick, Georgia

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  6. 2011 NOAA Ortho-rectified Mosaic of Intracoastal Waterway, Texas (NODC Accession 0105604)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  7. 2012 NOAA Ortho-rectified Mosaic of Oregon: Ports of Longview, Kalama, Vancouver, and Portland

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  8. 2012 NOAA NIR Ortho-rectified Mosaic of Oregon: Ports of Longview, Kalama, Vancouver, and Portland

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  9. 2016 NOAA NGS Ortho-rectified Near-Infrared Mosaic of Petersburg, Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  10. 2012 NOAA Ortho-rectified Near-Infrared Mosaic of Oregon: Lake Umatilla to Clarkson

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  11. 2015 NOAA NGS Ortho-rectified Color Mosaic of Jacksonville Beach to Mosquito Lagoon, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  12. 2012 NOAA Ortho-rectified Color Mosaic of Sacramento Deep Water Ship Channel, California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  13. 2012 NOAA Ortho-rectified Color Mosaic of Oregon: Columbia River - Bonneville Dam to Lake Umatilla

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  14. 2012 NOAA Ortho-rectified Color Mosaic of Bremerton and Manchester, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  15. 2016 NOAA NGS Ortho-rectified Near-Infrared Mosaic of Big Carlos Pass, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  16. 2013 NOAA Ortho-rectified Near-Infrared Mosaic of the Port of Panama City, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  17. 2013 NOAA Ortho-rectified Color Mosaic of the port of Panama City, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  18. 2010 NOAA Ortho-rectified Color Mosaic ofHudson River to Lake Champlain, New York

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  19. An overview of self-switching diode rectifiers using green materials

    Science.gov (United States)

    Kasjoo, Shahrir Rizal; Zailan, Zarimawaty; Zakaria, Nor Farhani; Isa, Muammar Mohamad; Arshad, Mohd Khairuddin Md; Taking, Sanna

    2017-09-01

    A unipolar two-terminal nanodevice, known as the self-switching diode (SSD), has recently been demonstrated as a room-temperature rectifier at microwave and terahertz frequencies due to its nonlinear current-voltage characteristic. The planar architecture of SSD not only makes the fabrication process of the device faster, simpler and at a lower cost when compared with other rectifying diodes, but also allows the use of various materials to realize and fabricate SSDs. This includes the utilization of `green' materials such as organic and graphene thin films for environmental sustainability. This paper reviews the properties of current `green' SSD rectifiers with respect to their operating frequencies and rectifying performances, including responsivity and noise-equivalent power of the devices, along with the applications.

  20. 2010 NOAA Ortho-rectified Mosaic from Color Aerial Imagery of LAKE CHARLES (NODC Accession 0075827)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative of LAKE CHARLES. The...

  1. 2010 NOAA Ortho-rectified Mosaic from Color Aerial Imagery of LAKE CHARLES

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative of LAKE CHARLES. The...

  2. 2011 NOAA Ortho-rectified Color Mosaic of Fire Island, New York

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  3. 2011 NOAA Color MHW Ortho-rectified Mosaic of Amelia Island and Nassau River, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  4. 2010 NOAA Ortho-rectified Mosaic from Color Aerial Imagery of CHOCTAWHATCHEE BAY

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative of CHOCTAWHATCHEE BAY....

  5. 2010 NOAA Ortho-rectified Mosaic from Color Aerial Imagery of MISSISSIPPI RIVER - LAPLACE TO VENICE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative of MISSISSIPPI RIVER -...

  6. 2011 NOAA Ortho-rectified Mosaic from Color Aerial Imagery of CHOCTAWHATCHEE BAY

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative of CHOCTAWHATCHEE BAY....

  7. 2013 NOAA Ortho-rectified Color Mosaic of Virginia: Norfolk, Hampton Roads,and Newport News

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  8. 2016 NOAA NGS Ortho-rectified Color Mosaic of Anchorage, Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  9. 2010 NOAA Ortho-rectified Mosaic from Color Aerial Imagery of PORT OF GEORGETOWN - CSCAP

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative of PORT OF GEORGETOWN...

  10. 2013 NOAA Ortho-rectified Color Mosaic of California: Port of San Diego

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  11. Time Delay of CGM Sensors

    Science.gov (United States)

    Schmelzeisen-Redeker, Günther; Schoemaker, Michael; Kirchsteiger, Harald; Freckmann, Guido; Heinemann, Lutz; del Re, Luigi

    2015-01-01

    Background: Continuous glucose monitoring (CGM) is a powerful tool to support the optimization of glucose control of patients with diabetes. However, CGM systems measure glucose in interstitial fluid but not in blood. Rapid changes in one compartment are not accompanied by similar changes in the other, but follow with some delay. Such time delays hamper detection of, for example, hypoglycemic events. Our aim is to discuss the causes and extent of time delays and approaches to compensate for these. Methods: CGM data were obtained in a clinical study with 37 patients with a prototype glucose sensor. The study was divided into 5 phases over 2 years. In all, 8 patients participated in 2 phases separated by 8 months. A total number of 108 CGM data sets including raw signals were used for data analysis and were processed by statistical methods to obtain estimates of the time delay. Results: Overall mean (SD) time delay of the raw signals with respect to blood glucose was 9.5 (3.7) min, median was 9 min (interquartile range 4 min). Analysis of time delays observed in the same patients separated by 8 months suggests a patient dependent delay. No significant correlation was observed between delay and anamnestic or anthropometric data. The use of a prediction algorithm reduced the delay by 4 minutes on average. Conclusions: Prediction algorithms should be used to provide real-time CGM readings more consistent with simultaneous measurements by SMBG. Patient specificity may play an important role in improving prediction quality. PMID:26243773

  12. Virtual Synchronous Machine-based Power Control in Active Rectifiers for Micro Grids

    OpenAIRE

    Perera, Aravinda

    2012-01-01

    This dissertation presents an analytical study on virtual synchronous machine-based power control in active rectifiers for micro grids supported by prototype modelling, simulation results and discussions.Popularity and demand of the distributed energy resources and renewable energy sources are increasing due to their economic and environmental friendliness. Concept of micro grid with an active rectifier (AR) interface has been found to be promising for smart integration of such distributed ge...

  13. A Single-Phase Boost Rectifier System for Wide Range of Load Variations

    OpenAIRE

    R Ghosh; Narayanan, G.

    2007-01-01

    Converters operated in discontinuous-conduction-mode (DCM)and in continuous-conduction-mode (CCM) are suitable for lighter and higher loads, respectively. A new, constant switching frequency based single-phase rectifier system is proposed, which operates in DCM and in CCM for outputs less than and greater than 50% rated load, respectively, covering a wide range of load variation. The power circuit and the control circuit of the proposed rectifier are easily configurable for DCM and CCM operat...

  14. Rectifier Fault Diagnosis and Fault Tolerance of a Doubly Fed Brushless Starter Generator

    OpenAIRE

    Liwei Shi; Zhou Bo

    2015-01-01

    This paper presents a rectifier fault diagnosis method with wavelet packet analysis to improve the fault tolerant four-phase doubly fed brushless starter generator (DFBLSG) system reliability. The system components and fault tolerant principle of the high reliable DFBLSG are given. And the common fault of the rectifier is analyzed. The process of wavelet packet transforms fault detection/identification algorithm is introduced in detail. The fault tolerant performance and output voltage experi...

  15. DEVELOPMENT OF CONTROLLED RECTIFIERS BASED ON THE BIPOLAR WITH STATIC INDUCTION TRANSISTORS (BSIT

    Directory of Open Access Journals (Sweden)

    F. I. Bukashev

    2016-01-01

    Full Text Available Aim. The aim of this study is to develop one of the most perspective semiconductor device suitable for creation and improvement of controlled rectifiers, bipolar static induction transistor.Methods. Considered are the structural and schematic circuit controlled rectifier based on bipolar static induction transistor (BSIT, and the criterion of effectiveness controlled rectifiers - equivalent to the voltage drop.Results. Presented are the study results of controlled rectifier layout on BSIT KT698I. It sets the layout operation at an input voltage of 2.0 V at a frequency up to 750 kHz. The efficiency of the studied layouts at moderate current densities as high as 90 % .Offered is optimization of technological route microelectronic controlled rectifier manufacturing including BSIT and integrated bipolar elements of the scheme management.Conclusion. It is proved that the most efficient use of the bipolar static induction transistor occurs at the low voltage controlled rectifiers 350-400 kHz, at frequencies in conjunction with a low-voltage control circuit.It is proved that the increase of the functional characteristics of the converters is connected to the expansion of the input voltage and output current ranges

  16. Line-frequency phase-controlled rectifiers with adaptive digital controllers

    Directory of Open Access Journals (Sweden)

    Vukić Vladimir Đ.

    2013-01-01

    Full Text Available This article deals with the influence of PI controller linear gain scheduling on the dynamic characteristics of the line-frequency phase-controlled rectifier. The examined device has digital control electronics of the DRI 07B type, based on the Intel 80C196 microcontroller. The realized adaptive PI controllers utilize wide variations of the current gain (Kp, decreasing linearly in proportion to the increase in the rectifier output current in the area of the discontinuous currents. Reaching the threshold of the rectifier's discontinuous current, the current gain of the PI voltage controller remains constant. Beside the improvement of the thyristor rectifier's static stability during operation with small output currents, implementation of the adaptive PI control also led to improvement of the voltage controller response in the case of load disturbance in the range of 13-90 % of the nominal rectifier output current. Transfer functions were analyzed for specific parts of the phase-controlled rectifier DRI 110-100 having nominal output parameters of 116 V and 100 A. The values of the relative damping and root-locus characteristics were analyzed in detail.

  17. Rectified factor networks for biclustering of omics data.

    Science.gov (United States)

    Clevert, Djork-Arné; Unterthiner, Thomas; Povysil, Gundula; Hochreiter, Sepp

    2017-07-15

    Biclustering has become a major tool for analyzing large datasets given as matrix of samples times features and has been successfully applied in life sciences and e-commerce for drug design and recommender systems, respectively. actor nalysis for cluster cquisition (FABIA), one of the most successful biclustering methods, is a generative model that represents each bicluster by two sparse membership vectors: one for the samples and one for the features. However, FABIA is restricted to about 20 code units because of the high computational complexity of computing the posterior. Furthermore, code units are sometimes insufficiently decorrelated and sample membership is difficult to determine. We propose to use the recently introduced unsupervised Deep Learning approach Rectified Factor Networks (RFNs) to overcome the drawbacks of existing biclustering methods. RFNs efficiently construct very sparse, non-linear, high-dimensional representations of the input via their posterior means. RFN learning is a generalized alternating minimization algorithm based on the posterior regularization method which enforces non-negative and normalized posterior means. Each code unit represents a bicluster, where samples for which the code unit is active belong to the bicluster and features that have activating weights to the code unit belong to the bicluster. On 400 benchmark datasets and on three gene expression datasets with known clusters, RFN outperformed 13 other biclustering methods including FABIA. On data of the 1000 Genomes Project, RFN could identify DNA segments which indicate, that interbreeding with other hominins starting already before ancestors of modern humans left Africa. https://github.com/bioinf-jku/librfn. djork-arne.clevert@bayer.com or hochreit@bioinf.jku.at.

  18. Long-pore Electrostatics in Inward-rectifier Potassium Channels

    Science.gov (United States)

    Robertson, Janice L.; Palmer, Lawrence G.; Roux, Benoît

    2008-01-01

    Inward-rectifier potassium (Kir) channels differ from the canonical K+ channel structure in that they possess a long extended pore (∼85 Å) for ion conduction that reaches deeply into the cytoplasm. This unique structural feature is presumably involved in regulating functional properties specific to Kir channels, such as conductance, rectification block, and ligand-dependent gating. To elucidate the underpinnings of these functional roles, we examine the electrostatics of an ion along this extended pore. Homology models are constructed based on the open-state model of KirBac1.1 for four mammalian Kir channels: Kir1.1/ROMK, Kir2.1/IRK, Kir3.1/GIRK, and Kir6.2/KATP. By solving the Poisson-Boltzmann equation, the electrostatic free energy of a K+ ion is determined along each pore, revealing that mammalian Kir channels provide a favorable environment for cations and suggesting the existence of high-density regions in the cytoplasmic domain and cavity. The contribution from the reaction field (the self-energy arising from the dielectric polarization induced by the ion's charge in the complex geometry of the pore) is unfavorable inside the long pore. However, this is well compensated by the electrostatic interaction with the static field arising from the protein charges and shielded by the dielectric surrounding. Decomposition of the static field provides a list of residues that display remarkable correspondence with existing mutagenesis data identifying amino acids that affect conduction and rectification. Many of these residues demonstrate interactions with the ion over long distances, up to 40 Å, suggesting that mutations potentially affect ion or blocker energetics over the entire pore. These results provide a foundation for understanding ion interactions in Kir channels and extend to the study of ion permeation, block, and gating in long, cation-specific pores. PMID:19001143

  19. High-efficiency MOSFET bridge rectifier for AlN MEMS cantilever vibration energy harvester

    Science.gov (United States)

    Takei, Ryohei; Okada, Hironao; Noda, Daiji; Ohta, Ryo; Takeshita, Toshihiro; Itoh, Toshihiro; Kobayashi, Takeishi

    2017-04-01

    We developed a high-efficiency MOSFET bridge rectifier for use in an aluminum nitride (AlN) piezoelectric MEMS cantilever vibration energy harvester (VEH). The bridge rectifier consists of four MOSFETs with a circuit configuration similar to that of a typical diode bridge rectifier. The output voltage of the full-wave rectification via the MOSFET bridge was simulated with an equivalent circuit model of the AlN VEH, which is extracted from an experimental result. The channel width of the MOSFET was designed to be adopted for use with a high-voltage and low-current AlN VEH. The designed rectifier was fabricated using the 0.18 µm high voltage technology of a commercially available CMOS foundry. The AlN VEH with our bridge rectifier generated a DC power of 0.514 µW at 2.49 V under an applied vibration with an acceleration amplitude of 0.5 m/s2 at a frequency of 46.6 Hz. The DC power is 1.4 times higher than that generated by the same AlN VEH with a MOSFET bridge consisting of commercially available discrete MOSFETs.

  20. Gate-Controlled BP-WSe2Heterojunction Diode for Logic Rectifiers and Logic Optoelectronics.

    Science.gov (United States)

    Li, Dong; Wang, Biao; Chen, Mingyuan; Zhou, Jun; Zhang, Zengxing

    2017-06-01

    p-n junctions play an important role in modern semiconductor electronics and optoelectronics, and field-effect transistors are often used for logic circuits. Here, gate-controlled logic rectifiers and logic optoelectronic devices based on stacked black phosphorus (BP) and tungsten diselenide (WSe 2 ) heterojunctions are reported. The gate-tunable ambipolar charge carriers in BP and WSe 2 enable a flexible, dynamic, and wide modulation on the heterojunctions as isotype (p-p and n-n) and anisotype (p-n) diodes, which exhibit disparate rectifying and photovoltaic properties. Based on such characteristics, it is demonstrated that BP-WSe 2 heterojunction diodes can be developed for high-performance logic rectifiers and logic optoelectronic devices. Logic optoelectronic devices can convert a light signal to an electric one by applied gate voltages. This work should be helpful to expand the applications of 2D crystals. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Possibility designing half-wave and full-wave molecular rectifiers by using single benzene molecule

    Science.gov (United States)

    Abbas, Mohammed A.; Hanoon, Falah H.; Al-Badry, Lafy F.

    2018-02-01

    This work focused on possibility designing half-wave and full-wave molecular rectifiers by using single and two benzene rings, respectively. The benzene rings were threaded by a magnetic flux that changes over time. The quantum interference effect was considered as the basic idea in the rectification action, the para and meta configurations were investigated. All the calculations are performed by using steady-state theoretical model, which is based on the time-dependent Hamiltonian model. The electrical conductance and the electric current are considered as DC output signals of half-wave and full-wave molecular rectifiers. The finding in this work opens up the exciting potential to use these molecular rectifiers in molecular electronics.

  2. Simulation Study of Three - phase PWM Rectifier with Square of the Voltage Double Closed Loop Control

    Science.gov (United States)

    Qiang, Wen; Yong-bao, Liu; Xing, He; Qian-chao, Liang

    2017-05-01

    Based on the rotating coordinate system model, the mathematic analysis of the three-phase voltage-sourced PWM rectifier is carried out, and its feed-forward decoupling control strategy is studied. In order to realize the fast response of DC voltage and improve the dynamic and static performance of the rectifier, the double-closed-loop control of outer square of voltage loop and inner current loop is established. The control system of three-phase voltage-sourced PWM rectifier based on space vector modulation algorithm is designed. The simulation results demonstrate the designed model is accurate, and can achieve unity power factor control, DC voltage fast responses, and has not steady-state error.

  3. Theoretical study on the rectifying performance of organoimido derivatives of hexamolybdates.

    Science.gov (United States)

    Wen, Shizheng; Yang, Guochun; Yan, Likai; Li, Haibin; Su, Zhongmin

    2013-02-25

    We design a new type of molecular diode, based on the organoimido derivatives of hexamolybdates, by exploring the rectifying performances using density functional theory combined with the non-equilibrium Green's function. Asymmetric current-voltage characteristics were obtained for the models with an unexpected large rectification ratio. The rectifying behavior can be understood by the asymmetrical shift of the transmission peak observed under different polarities. It is interesting to find that the preferred electron-transport direction in our studied system is different from that of the organic D-bridge-A system. The results show that the studied organic-inorganic hybrid systems have an intrinsically robust rectifying ratio, which should be taken into consideration in the design of the molecular diodes. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Towards a 30kW/liter, Three-Phase Unity Power Factor Rectifier

    Science.gov (United States)

    Round, Simon; Karutz, Philipp; Heldwein, Marcelo; Kolar, Johann W.

    In this paper, a forced air-cooled, 400kHz, 10kW Vienna Rectifier with a power density of 8.5kW/liter is presented. To further improve the power density, the switching frequency is increased to reduce the EMI filter volume. A design for an 18.5kW/liter, 2.5MHz rectifier is proposed. By using today's technology, it is calculated that the maximum power density for a forced air-cooled and water-cooled rectifier is 20.8kW/liter and 24kW/liter respectively. To achieve 30kW/liter, improvements must be made in passive component material properties, reducing semiconductor losses and improving the cooling system.

  5. Initial Rotor Position Estimation of Half-Wave Rectified Brushless Synchronous Motor

    Science.gov (United States)

    Abe, Takashi; Oyama, Jun; Higuchi, Tsuyoshi

    This paper presents an initial rotor position estimation of Half-Wave Rectified Brushless Synchronous Motor. In the previous paper, we proposed this motor as AC servo motor, which is based on the half-wave rectified brushless excitation principle. The basic principle of this estimation technique utilizes the dependence of inductance on the rotor position. The bias frequency component of half-Wave rectified brushless excitation is used to estimate the rotor position error. The magnetic pole is discriminated by the switching condition of the diode inserted into the rotor field winding. This estimation technique is confirmed by simulation include inverter circuit, control program and motor model. Finally, the effectiveness of the proposed estimation technique has been verified by experiments.

  6. EFFECT OF CAST RECTIFIERS ON THE MARGINAL FIT OF UCLA ABUTMENTS

    Science.gov (United States)

    Jaime, Ana Paula Gumieiro; de Vasconcellos, Diego Klee; Mesquita, Alfredo Mikail Melo; Kimpara, Estevão Tomomitsu; Bottino, Marco Antonio

    2007-01-01

    Objectives: This study assessed the effect of cast rectifiers on the marginal misfit of cast UCLA abutments compared to premachined UCLA abutments. The influence of casting and porcelain baking on the marginal misfit of these components was also investigated. Methods: Two groups were analyzed: test group – 10 cast UCLA abutments, finished with cast rectifier and submitted to ceramic application; control group – 10 premachined UCLA abutments, cast with noble metal alloy and submitted to ceramic application. Vertical misfit measurements were performed under light microscopy. In the test group, measurements were performed before and after the use of cast rectifiers, and after ceramic application. In the control group, measurements were performed before and after casting, and after ceramic application. Data were submitted to statistical analysis by ANOVA and Tukey's test (α= 5%). Results: The use of cast rectifiers significantly reduced the marginal misfit of cast UCLA abutments (from 25.68μm to 14.83μm; p<0.05). After ceramic application, the rectified cylinders presented misfit values (16.18μm) similar to those of premachined components (14.3 μm). Casting of the premachined UCLA abutments altered the marginal misfit of these components (from 9.63 μm to 14.6 μm; p<0.05). There were no significant changes after porcelain baking, in both groups. Conclusion: The use of cast rectifiers reduced the vertical misfit of cast UCLA abutments. Even with carefully performed laboratory steps, changes at the implant interface of premachined UCLA abutments occurred. Ceramic application did not alter the marginal misfit values of UCLA abutments. PMID:19089125

  7. Effect of cast rectifiers on the marginal fit of UCLA abutments

    Directory of Open Access Journals (Sweden)

    Ana Paula Gumieiro Jaime

    2007-06-01

    Full Text Available OBJECTIVES: This study assessed the effect of cast rectifiers on the marginal misfit of cast UCLA abutments compared to premachined UCLA abutments. The influence of casting and porcelain baking on the marginal misfit of these components was also investigated. METHODS: Two groups were analyzed: test group - 10 cast UCLA abutments, finished with cast rectifier and submitted to ceramic application; control group - 10 premachined UCLA abutments, cast with noble metal alloy and submitted to ceramic application. Vertical misfit measurements were performed under light microscopy. In the test group, measurements were performed before and after the use of cast rectifiers, and after ceramic application. In the control group, measurements were performed before and after casting, and after ceramic application. Data were submitted to statistical analysis by ANOVA and Tukey's test (a= 5%. RESULTS: The use of cast rectifiers significantly reduced the marginal misfit of cast UCLA abutments (from 25.68mm to 14.83mm; p<0.05. After ceramic application, the rectified cylinders presented misfit values (16.18mm similar to those of premachined components (14.3 mm. Casting of the premachined UCLA abutments altered the marginal misfit of these components (from 9.63 mm to 14.6 mm; p<0.05. There were no significant changes after porcelain baking, in both groups. CONCLUSION: The use of cast rectifiers reduced the vertical misfit of cast UCLA abutments. Even with carefully performed laboratory steps, changes at the implant interface of premachined UCLA abutments occurred. Ceramic application did not alter the marginal misfit values of UCLA abutments.

  8. Recovery Act: High-Efficiency, Wideband Three-Phase Rectifiers and Adaptive Rectifier Management for Telecomm Central Office and Large Data Center Applications

    Energy Technology Data Exchange (ETDEWEB)

    Mark A. Johnson

    2012-06-29

    Lineage Power and Verizon teamed up to address a DOE funding opportunity focused on improving the power conversion chain in telecommunications facilities and data centers. The project had three significant elements: the design and development of high efficiency and high power three-phase rectifiers by Lineage Power, design and development of software to optimize overall plant energy efficiency by Lineage Power, and a field trial in active Verizon telecommunications facilities where energy consumption was measured before and after efficiency upgrades.

  9. Single-Phase Boost Rectifier with Resonant Snubber Switch Cell Operating in DCM

    Science.gov (United States)

    Itoh, Ryozo; Ishizaka, Kouichi; Neba, Yasuhiko; Matsumoto, Hirokazu

    Single-phase boost rectifier with a resonant snubber switch cell is studied. The resonant snubber switch cell consists of an only active power switching device and a LC resonant circuit, and can also provide the necessary control over the current. To turn on and off an active power device under the soft switching conditions, the rectifier is operated in the discontinuous conduction mode (DCM). The experimental results under the charge control confirm that the input current can nearly be wave-shaped sinusoidally with a near-unity power factor.

  10. Rectifier Design Challenges for RF Wireless Power Transfer and Energy Harvesting Systems

    Directory of Open Access Journals (Sweden)

    A. Collado

    2017-06-01

    Full Text Available The design of wireless power transfer (WPT and energy harvesting (EH solutions poses different challenges towards achieving maximum RF-DC conversion efficiency in these systems. This paper covers several selected challenges when developing WPT and electromagnetic EH solutions, such as the design of multiband and broadband rectifiers, the minimization of the effect that load and input power variations may have on the system performance and finally the most optimum power combining mechanisms that can be used when dealing with multi-element rectifiers.

  11. Rectified transport of chiral active particles in the two-dimensional channel with varied upper wall

    Science.gov (United States)

    Huang, Xiao-qun; An, Meng

    2018-02-01

    Rectified transport of chiral self-propelled particles is numerically investigated in a two-dimensional channel with varied upper wall. Due to the chirality of active particles, the transversal asymmetry can break the symmetry of the system and induce a longitudinal net transport. It is found that the variation of the channel walls can strongly affect the rectified transport. There exist optimal values of the parameters (the variation parameter, the self-propelled velocity, the angular velocity, and the translational diffusion) at which the scaled average velocity takes its maximal value.

  12. Analysis of Three-Phase Rectifier Systems with Controlled DC-Link Current Under Unbalanced Grids

    DEFF Research Database (Denmark)

    Kumar, Dinesh; Davari, Pooya; Zare, Firuz

    2017-01-01

    Voltage unbalance is the most common disturbance in distribution networks, which give undesirable effects on many grid connected power electronics systems including Adjustable Speed Drive (ASD). Severe voltage unbalance can force three-phase rectifiers into almost single-phase operation, which...... degrades the grid power quality and also imposes a significant negative impact on the ASD system. This major power quality issue affecting the conventional rectifiers can be attenuated by controlling the DC-link current based on an Electronic Inductor (EI) technique. The purpose of this digest...

  13. Design and control of an LCL-filter-based three-phase active rectifier

    DEFF Research Database (Denmark)

    Liserre, Marco; Blaabjerg, Frede; Hansen, Steffan

    2005-01-01

    This paper proposes a step-by-step procedure for designing the LCL filter of a front-end three-phase active rectifier. The primary goal is to reduce the switching frequency ripple at a reasonable cost, while at the same time achieving a high-performance front-end rectifier (as characterized...... controller. The system is stable and the grid current harmonic content is low both in the lowand high-frequency ranges. Moreover, the good agreement that was obtained between simulation and experimental results validates the proposed approach. Hence, the design procedure and the simulation model provide...

  14. Static analysis of rectifier cabinet for nuclear power generating stations based on finite element method

    Science.gov (United States)

    Yin, Qiang; Chen, Tian-jin; Li, Wei-yang; Xiong, Ze-cheng; Ma, Rui

    2017-09-01

    In order to obtain the deformation map and equivalent stress distribution of rectifier cabinet for nuclear power generating stations, the quality distribution of structure and electrical are described, the tensile bond strengths of the rings are checked, and the finite element model of cabinet is set up by ANSYS. The transport conditions of the hoisting state and fork loading state are analyzed. The deformation map and equivalent stress distribution are obtained. The attentive problems are put forward. It is a reference for analysis method and the obtained results for the transport of rectifier cabinet for nuclear power generating stations.

  15. The first-principles study of oscillating rectifying performance in nanoribbon-chain-carbon nanotube junctions

    Science.gov (United States)

    Qiu, Ming; Liew, K. M.

    2013-05-01

    Electronic transport properties of armchair graphene nanoribbon and capped carbon nanotube junctions, covalently bridged by carbon atomic chains with different numbers of carbon atoms, are investigated. The first-principles calculations based on non-equilibrium Green's functions with the density-functional theory show that their I-V characteristics display odd-even effects and rectifying behaviors show obvious oscillations, namely, different bond patterns for even- and odd-numbered carbon chains affect the contact bonds, charge transfer, density of states, evolutions of molecular orbitals, and rectifying performance.

  16. Diode rectifier bridge-based structure for DFIG-based wind turbine

    DEFF Research Database (Denmark)

    Zhu, Rongwu; Chen, Zhe; Wu, Xiaojie

    2015-01-01

    This paper proposes a new structure for the doubly-fed induction generator (DFIG)-based wind turbine. The proposed structure consists of a DFIG controlled by a partial rated power converter in the rotor side, a three-phase diode rectifier bridge (DRB) connected to the stator, and a DC/AC full rated...

  17. Ac loss measurements on a superconducting transformer for a 25 kA superconducting rectifier

    NARCIS (Netherlands)

    ten Kate, Herman H.J.; Mulders, J.M.; de Reuver, J.L.; van de Klundert, L.J.M.

    1984-01-01

    Ac loss measurements have been performed on a superconducting transformer. The transformer is a part of a 25 kA thermally switched superconducting rectifier operating at a frequency of 0.1 Hz. The loss measurements have been automatized by means of a microcomputer sampling four relevant signals and

  18. Transformer-rectifier flux pump using inductive current transfer and thermally controlled Nb(3)Sn cryotrons.

    Science.gov (United States)

    Atherton, D L; Davies, R

    1979-10-01

    Transformer-rectifier flux pumps using thermally switched Nb(3)Sn cryotrons are being investigated as a loss make-up device for the proposed isochorically operated (sealed) superconducting magnets for the Canadian Maglev vehicle. High currents (1000 A) were obtained in an experimental flux pump using inductive current transfer and operating at 2 Hz.

  19. Development of a 50-60 Hz thermally switched superconducting rectifier

    NARCIS (Netherlands)

    Chevtchenko, O.A.; ten Kate, Herman H.J.; Krooshoop, Hendrikus J.G.; Markovsky, N.V.; Mulder, G.B.J.; Mulder, G.B.J.

    1993-01-01

    A full-wave thermally switched superconducting rectifier, able to operate directly from the mains at the 50-60-Hz frequency, has been developed. Typical design output values of this device are a current of 300 A, a voltage of up to 1 V, an average power of up to 100 VA, and an efficiency better than

  20. Development of a thermally switched superconducting rectifier for 100 kA

    NARCIS (Netherlands)

    Mulder, G.B.J.; Mulder, G.B.J.; ten Kate, Herman H.J.; Krooshoop, Hendrikus J.G.; van de Klundert, L.J.M.; van de Klundert, L.J.M.

    1991-01-01

    A full-wave superconducting rectifier for 100 kA has been developed. Typical design values of this device are: a secondary current of 100 kA, a primary amplitude of 20 A, an operating frequency of 0.5 Hz, and an average power on the order of 100 W. The rectification is achieved by means of thermally

  1. Crossbar memory array of organic bistable rectifying diodes for nonvolatile data storage

    NARCIS (Netherlands)

    Asadi, K.; Li, M.; Stingelin, N.; Blom, P.W.M.; Leeuw, D.M. de

    2010-01-01

    Cross-talk in memories using resistive switches in a cross-bar geometry can be prevented by integration of a rectifying diode. We present a functional cross bar memory array using a phase separated blend of a ferroelectric and a semiconducting polymer as storage medium. Each intersection acts

  2. Connection of OWPPs to HVDC networks using VSCs and Diode Rectifiers: an Overview

    DEFF Research Database (Denmark)

    Saborío-Romano, Oscar; Bidadfar, Ali; Göksu, Ömer

    This paper provides an overview of two technologies for connecting offshore wind power plants (offshore WPPs, OWPPs) to high-voltage direct current (HVDC) networks: voltage source converters (VSCs) and diode rectifiers (DRs). Current grid code requirements for the connection of such power plants...

  3. A Saturated Output Feedback Controller for the Three Phase Voltage Sourced Reversible Boost Type Rectifier

    NARCIS (Netherlands)

    Escobar, Gerardo; Ortega, Romeo; Schaft, Arjan J. van der

    1998-01-01

    In this article, we present a saturating controller to regulate the output voltage load in a three phase Boost type rectifier. The controller only needs the output voltage signal to be implemented. Moreover, by forcing the inductance currents to track desired suitable sinusoidal signals in phase

  4. Design of the LC+trap filter for a current source rectifier

    DEFF Research Database (Denmark)

    Min, Huang; Wang, Xiongfei; Loh, Poh Chiang

    2015-01-01

    This paper investigates an LC + trap filter for current source converters to improve the switching harmonic attenuation. The resonant frequency characteristics of the filter of current source rectifier are analyzed. A filter design procedure is proposed based on the input power factor, filter...

  5. Effect of ethanol at clinically relevant concentrations on atrial inward rectifier potassium current sensitive to acetylcholine

    Czech Academy of Sciences Publication Activity Database

    Bébarová, M.; Matejovič, P.; Pásek, Michal; Hořáková, Z.; Hošek, J.; Šimurdová, M.; Šimurda, J.

    2016-01-01

    Roč. 389, č. 10 (2016), s. 1049-1058 ISSN 0028-1298 Institutional support: RVO:61388998 Keywords : arrhythmias * atrial cardiomyocyte * inward rectifier potasssium current * ethanol * rat atrial cell model Subject RIV: BO - Biophysics Impact factor: 2.558, year: 2016

  6. Performance improvement of three phase rectifier by employing electronic smoothing inductor

    DEFF Research Database (Denmark)

    Singh, Yash Veer; Rasmussen, Peter Omand; Andersen, Torben O.

    2014-01-01

    An electronic smoothing inductor (ESI) is very attractive circuit topology to improve power factor and to reduce the total harmonic distortions (THDs) of the ac mains current in a three phase diode bridge rectifier. The ESI reduces the low frequency ripples and controls the intermediate dc...

  7. A Three-Phase Triple Voltage Rectifier Circuit Using Diode Charge Pump Scheme

    Science.gov (United States)

    Sakui, Masaaki; Shimizu, Tsubasa; Amei, Kenji; Ohji, Takahisa

    A novel three-phase triple-voltage rectifier circuit is presented. The proposed circuit applies the single-phase diode charge pump scheme to the three-phase system and the direct output voltage is about 3 times much than input line-to-line voltage. The validity for the proposed circuit is demonstrated by the simulations and the experiments.

  8. Current Mode Full-Wave Rectifier Based on a Single MZC-CDTA

    Directory of Open Access Journals (Sweden)

    Neeta Pandey

    2013-01-01

    Full Text Available This paper presents a current mode full-wave rectifier based on single modified Z copy current difference transconductance amplifier (MZC-CDTA and two switches. The circuit is simple and is suitable for IC implementation. The functionality of the circuit is verified with SPICE simulation using 0.35 μm TSMC CMOS technology parameters.

  9. Study on the formation of current characteristics of a silicon photodiode with rectifying barriers

    Directory of Open Access Journals (Sweden)

    Karimov A. V.

    2013-02-01

    Full Text Available The article presents the results of studies on silicon photodiode double-barrier structure with back-to-back rectifying junctions «metal — semiconductor» in the photodiode and photovoltaic modes. Such structures are of interest for the development of input devices for weak optical signals.

  10. On the possibilities of electric power quality control via electric loads with active rectifiers

    Directory of Open Access Journals (Sweden)

    Володимир Володимирович Бурлака

    2017-07-01

    Full Text Available The paper proposes a method for controlling the electric power quality parameters in a distribution network by modifying the control algorithms for electric loads equipped with active rectifiers fed from this network. Thus, by controlling the reactive component of the input current of such rectifiers, it is possible to reduce the voltage fluctuations at the point of common connection (PCC, the efficiency of such a method being higher the higher the X/R ratio of the network is. It is also possible to reduce the voltage harmonics in the PCC by integrating the functions of parallel active filters into active rectifiers. The proposed method allows for limited control over the flow of inactive power in the distribution network, which makes it possible to improve the electric power quality and reduce the required power of the filter compensating devices. The proposed algorithm for controlling the active rectifier is tested on the mathematical model of group loads. A group of high power resistance welding machines (RWMs operating randomly with a normal probability distribution connected to 0,4 kV grid as a non-stationary load is used. The application of the proposed reactive current control method in the RWM power supplies made it possible to reduce the voltage fluctuations in 0,4 kV grid from 12% to 5%.

  11. Active and reactive power control of a current-source PWM-rectifier using space vectors

    Energy Technology Data Exchange (ETDEWEB)

    Salo, M.; Tuusa, H. [Tampere University of Technology (Finland). Department of Electrical Engineering, Power Electronics

    1997-12-31

    In this paper the current-source PWM-rectifier with active and reactive power control is presented. The control system is realized using space vector methods. Also, compensation of the reactive power drawn by the line filter is discussed. Some simulation results are shown. (orig.) 8 refs.

  12. Zero sequence blocking transformers for multi-pulse rectifier in aerospace applications

    DEFF Research Database (Denmark)

    Yao, Wenli; Blaabjerg, Frede; Zhang, Xiaobin

    2014-01-01

    The power electronics technology plays an even more important role in the aerospace applications of More Electric Aircrafts (MEA). AutoTransformer Rectifier Units (ATRU) have been widely adopted in aircrafts due to its simplicity and reliability. In this paper, Zero Sequence Blocking Transformers...

  13. Commutation Characteristics of Snubber Circuits of PWM Rectifier for Converter without DC Link Components

    Science.gov (United States)

    Iimori, Kenichi; Shinohara, Katsuji; Yamamoto, Kichiro; Ikeda, Motonobu

    This paper describes commutation characteristics of snubber circuits of the PWM rectifier for the converter without DC link components. The DC link part of this converter has no smoothing circuit such as electrolytic capacitors and reactors. Therefore, one of the switches in the upper arms and one of the switches in the lower arms of the rectifier must be on-state in order to assure the path of the load current. The rectifier section of this converter requires the LC filter to improve the AC source current waveforms. Consequently, dead time should be applied to each of the commutation switches to prevent short circuit through the filter capacitors. The currents of the load are kept through the snubber circuit during the dead-time period. In this paper, we discuss an analytical method of the converter with the snubber circuit of the rectifier, and the experimental results are used to verify the analytical method. Next, the optimal snubber parameters are determined by calculation for 0.75kW induction motor driven by this converter. Finally, suitable snubber circuits for bidirectional switches are discussed.

  14. Comparative Evaluation of Three-Phase Isolated Matrix-Type PFC Rectifier Concepts for High Efficiency 380VDC Supplies of Future Telco and Data Centers

    DEFF Research Database (Denmark)

    Cortes, Patricio; Bortis, Dominik; Pittini, Riccardo

    2014-01-01

    is located at the input of the PFC rectifier. In this paper, an overview of isolated matrix-type PFC rectifier topologies is given and a new converter circuit is proposed, analyzed and comparatively evaluated against another promising PFC rectifier concept, the phase-modular IMY-rectifier....... rectifier and in many cases a mains transformer is used to provide galvanic isolation. In order to achieve a high efficiency in the DC voltage generation and to implement the required isolation, a single-stage concept, such as a matrix-type rectifier that enables PFC functionality and galvanic isolation...... in a single conversion, can be beneficial. In addition, due to the fact that with the matrix-type rectifier the galvanic isolation is performed with a high-frequency transformer, this results in a more compact rectifier system compared to conventional systems where the mains-frequency isolation transformer...

  15. Design, fabrication, and characterization of 4H-silicon carbide rectifiers for power switching applications

    Science.gov (United States)

    Sheridan, David Charles

    Silicon Carbide has received a substantial increase in research interest over the past few years as a base material system for high-frequency and high-power semiconductor devices. Of the over 1200 polytypes, 4H-SiC is the most attractive polytype for power devices due to its wide band gap (3.2eV), excellent thermal conductivity (4.9 W/cm·K), and high critical field strength (˜2 x 106 V/cm). Important for power devices, the 10x increase in critical field strength of SiC allows high voltage blocking layers to be fabricated significantly thinner than for comparable Si devices. For power rectifiers, this reduces device on-resistance, while maintaining the same high voltage blocking capability. In this work, 4H-SiC Schottky, pn, and junction barrier Schottky (JBS) rectifiers for use in high voltage switching applications have been designed, fabricated, and extensively characterized. First, a detailed review of 4H-SiC material parameters was performed and SiC models were implemented into a standard Si drift-diffusion numerical simulator. Using these models, a SiC simulation methodology was developed in order to enable predictive SiC device design. A wide variety of rectifier and edge termination designs were investigated and optimized with respect to breakdown efficiency, area consumption, resistance to interface charge, and fabrication practicality. Simulated termination methods include: field plates, floating guard rings, and a variety of junction termination extensions (JTE). Using the device simulation results, both Schottky and JBS rectifiers were fabricated with a novel self-aligned edge termination design, and fabricated with process elements developed at the Alabama Microelectronics Science and Technology Center facility. These rectifiers exhibited near-ideal forward characteristics and had blocking voltages in excess of 2.5kV. The SiC diodes were subjected to inductive switching tests, and were found to have superior reverse recovery characteristics compared

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

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Chiarantoni, Ernesto; Aquila, Antonio Dell’

    2004-01-01

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

  17. Development of 24GHz Rectenna for Receiving and Rectifying Modulated Waves

    Science.gov (United States)

    Shinohara, Naoki; Hatano, Ken

    2014-11-01

    In this paper, we show experimental results of RF-DC conversion with modulated 24GHz waves. We have already developed class-F MMIC rectenna with resonators for higher harmonics at no modulated 24GHz microwave for RF energy transfer. Dimensions of the MMIC rectifying circuit is 1 mm × 3 mm on GaAs. Maximum RF-DC conversion efficiency is measured 47.9% for a 210 mW microwave input of 24 GHz with a 120 Ω load. The class-F rectenna is based on a single shunt full-wave rectifier. For future application of a simultaneous energy and information transfer system or an energy harvesting from broadcasting waves, input microwave will be modulated. In this paper, we show an experimental result of RF-DC conversion of the class-F rectenna with 24GHz waves modulated by 16QAM as 1st modulation and OFDM as 2nd modulation.

  18. $L^{p}$-square function estimates on spaces of homogeneous type and on uniformly rectifiable sets

    CERN Document Server

    Hofmann, Steve; Mitrea, Marius; Morris, Andrew J

    2017-01-01

    The authors establish square function estimates for integral operators on uniformly rectifiable sets by proving a local T(b) theorem and applying it to show that such estimates are stable under the so-called big pieces functor. More generally, they consider integral operators associated with Ahlfors-David regular sets of arbitrary codimension in ambient quasi-metric spaces. The local T(b) theorem is then used to establish an inductive scheme in which square function estimates on so-called big pieces of an Ahlfors-David regular set are proved to be sufficient for square function estimates to hold on the entire set. Extrapolation results for L^p and Hardy space versions of these estimates are also established. Moreover, the authors prove square function estimates for integral operators associated with variable coefficient kernels, including the Schwartz kernels of pseudodifferential operators acting between vector bundles on subdomains with uniformly rectifiable boundaries on manifolds.

  19. A Single Nonlinear Current Control for PWM Rectifier Robust to Input Disturbances and Dynamic Loads

    Directory of Open Access Journals (Sweden)

    Nancy Visairo-Cruz

    2017-01-01

    Full Text Available The requirements of PWM rectifiers for delivering power to motor drives include power factor correction and output voltage regulation even when strong variations such as voltage sags and dynamic load transients occur simultaneously. To achieve these objectives, the classic approach is to use a two-loop controller with its d-q model. In this paper, the authors propose a simplified approach to address that problem by using a feedback linearization-based nonlinear controller using only a single-loop current control and avoiding d-q modeling to reduce processing stages. To demonstrate the feasibility of this approach, several simulations are presented considering a 1.5 kW PWM rectifier.

  20. Electrical and Optical Properties of Rectifying ZnO Homojunctions Fabricated by Wet Chemistry Methods

    Czech Academy of Sciences Publication Activity Database

    Yatskiv, Roman; Tiagulkyi, Stanislav; Grym, Jan; Černohorský, Ondřej

    2018-01-01

    Roč. 215, č. 2 (2018), č. článku 1700592. ISSN 1862-6300 R&D Projects: GA ČR(CZ) GA17-00546S; GA ČR(CZ) GA15-17044S Institutional support: RVO:67985882 Keywords : Rectifying ZnO homojunctions * Photoluminescence * N-type nanorods Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.775, year: 2016

  1. Simulation of a rectifier malfunction on an offshore wind system with HVDC transmission

    OpenAIRE

    Melicio, Rui

    2015-01-01

    A new integrated mathematical model for the simulation of an offshore wind system having a rectifier input voltage malfunction at one phase is presented in this paper. The mathematical model considers an offshore variable-speed wind turbine on a floating platform, equipped with a permanent magnet synchronous generator using full-power three-level converter to inject energy into the electric network, through a high voltage direct current transmission submarine cable. The model for the drive tr...

  2. Active Rectifier with Extended Functions: An Option to Voltage Sags Ride Through and Power Quality Improvement

    Directory of Open Access Journals (Sweden)

    Echavarría–Solís R.

    2010-07-01

    Full Text Available The power quality concept, is usually confused with energy saving. However, even if energy saving is desirable over all in industry applications, the first concept does not implie the second one. For the electrical engineers, the improvement of power quality using the existing converters is a great challenge. This paper deals with a multilevel, single phase active rectifier whose main objective is to compensate power factor which, with an adequate control, provides voltage sag compensation and power quality conditioning

  3. Low cost, p-ZnO/n-Si, rectifying, nano heterojunction diode: Fabrication and electrical characterization.

    Science.gov (United States)

    Kabra, Vinay; Aamir, Lubna; Malik, M M

    2014-01-01

    A low cost, highly rectifying, nano heterojunction (p-ZnO/n-Si) diode was fabricated using solution-processed, p-type, ZnO nanoparticles and an n-type Si substrate. p-type ZnO nanoparticles were synthesized using a chemical synthesis route and characterized by XRD and a Hall effect measurement system. The device was fabricated by forming thin film of synthesized p-ZnO nanoparticles on an n-Si substrate using a dip coating technique. The device was then characterized by current-voltage (I-V) and capacitance-voltage (C-V) measurements. The effect of UV illumination on the I-V characteristics was also explored and indicated the formation of a highly rectifying, nano heterojunction with a rectification ratio of 101 at 3 V, which increased nearly 2.5 times (232 at 3 V) under UV illumination. However, the cut-in voltage decreases from 1.5 V to 0.9 V under UV illumination. The fabricated device could be used in switches, rectifiers, clipper and clamper circuits, BJTs, MOSFETs and other electronic circuitry.

  4. Low cost, p-ZnO/n-Si, rectifying, nano heterojunction diode: Fabrication and electrical characterization

    Directory of Open Access Journals (Sweden)

    Vinay Kabra

    2014-11-01

    Full Text Available A low cost, highly rectifying, nano heterojunction (p-ZnO/n-Si diode was fabricated using solution-processed, p-type, ZnO nanoparticles and an n-type Si substrate. p-type ZnO nanoparticles were synthesized using a chemical synthesis route and characterized by XRD and a Hall effect measurement system. The device was fabricated by forming thin film of synthesized p-ZnO nanoparticles on an n-Si substrate using a dip coating technique. The device was then characterized by current–voltage (I–V and capacitance–voltage (C–V measurements. The effect of UV illumination on the I–V characteristics was also explored and indicated the formation of a highly rectifying, nano heterojunction with a rectification ratio of 101 at 3 V, which increased nearly 2.5 times (232 at 3 V under UV illumination. However, the cut-in voltage decreases from 1.5 V to 0.9 V under UV illumination. The fabricated device could be used in switches, rectifiers, clipper and clamper circuits, BJTs, MOSFETs and other electronic circuitry.

  5. Microfluidic rectifier based on poly(dimethylsiloxane) membrane and its application to a micropump.

    Science.gov (United States)

    Wang, Yao-Nan; Tsai, Chien-Hsiung; Fu, Lung-Ming; Lin Liou, Lung-Kai

    2013-01-01

    A microfluidic rectifier incorporating an obstructed microchannel and a PDMS membrane is proposed. During forward flow, the membrane deflects in the upward direction; thereby allowing the fluid to pass over the obstacle. Conversely, during reverse flow, the membrane seals against the obstacle, thereby closing the channel and preventing flow. It is shown that the proposed device can operate over a wide pressure range by increasing or decreasing the membrane thickness as required. A microfluidic pump is realized by integrating the rectifier with a simple stepper motor mechanism. The experimental results show that the pump can achieve a vertical left height of more than 2 m. Moreover, it is shown that a maximum flow rate of 6.3 ml/min can be obtained given a membrane thickness of 200 μm and a motor velocity of 80 rpm. In other words, the proposed microfluidic rectifier not only provides an effective means of preventing reverse flow but also permits the realization of a highly efficient microfluidic pump.

  6. Rectifying the output of vibrational piezoelectric energy harvester using quantum dots.

    Science.gov (United States)

    Li, Lijie

    2017-03-20

    Piezoelectric energy harvester scavenges mechanical vibrations and generates electricity. Researchers have strived to optimize the electromechanical structures and to design necessary external power management circuits, aiming to deliver high power and rectified outputs ready for serving as batteries. Complex deformation of the mechanical structure results in charges with opposite polarities appearing on same surface, leading to current loss in the attached metal electrode. External power management circuits such as rectifiers comprise diodes that consume power and have undesirable forward bias. To address the above issues, we devise a novel integrated piezoelectric energy harvesting device that is structured by stacking a layer of quantum dots (QDs) and a layer of piezoelectric material. We find that the QD can rectify electrical charges generated from the piezoelectric material because of its adaptable conductance to the electrochemical potentials of both sides of the QDs layer, so that electrical current causing energy loss on the same surface of the piezoelectric material can be minimized. The QDs layer has the potential to replace external rectification circuits providing a much more compact and less power-consumption solution.

  7. 2015 NOAA Ortho-rectified Color Mosaic of Port Everglades, Florida: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  8. 2014 NOAA Ortho-rectified Color Mosaic of The Everglades, Florida: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  9. Pulse generator using transistors and silicon controlled rectifiers produces high current pulses with fast rise and fall times

    Science.gov (United States)

    Woolfson, M. G.

    1966-01-01

    Electrical pulse generator uses power transistors and silicon controlled rectifiers for producing a high current pulse having fast rise and fall times. At quiescent conditions, the standby power consumption of the circuit is equal to zero.

  10. 2010 NOAA Ortho-rectified Mosaic from Color Aerial Imagery of BEAUMONT, ORANGE, PORT AUTHUR (NODC Accession 0074380)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative of BEAUMONT, ORANGE,...

  11. 2013 NOAA Ortho-rectified Near-Infrared Mosaic of Intercoastal Waterway - Calcasieu Lake to Vermillion Bay, Louisiana

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  12. 2014 NOAA NGS Ortho-rectified Mean Low Low Water Color Mosaic of Venice Inlet ICW, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  13. 2013 NOAA Ortho-rectified Color MLLW Mosaic of South Carolina: Hilton Head to St. Helena Sound

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  14. 2012 NOAA Ortho-rectified Color Mosaic of Christiansted Harbor, St. Croix, U.S. Virgin Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  15. 2016 NOAA NGS Ortho-rectified Mean Low Low Water Color Mosaic of St Johns River, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  16. 2013 NOAA Ortho-rectified Mean High Water Color Mosaic of Calcasieu Lake and Lake Charles, Louisiana

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  17. 2016 NOAA NGS Ortho-rectified Near-Infrared Mosaic of Muskegon, Grand Haven,and Holland, Michigan

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  18. 2012 NOAA Ortho-rectified Near-Infrared MLLW Mosaic of Pescadero Point to Bodega Bay, California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  19. 2010 NOAA Ortho-rectified Near-infrared Mosaic of Hudson River to Lake Champlain, New York

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  20. 2012 NOAA Ortho-rectified Near-Infrared Mosaic of Oregon: Columbia River - Bonneville Dam to Lake Umatilla

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  1. 2011 NOAA Ortho-rectified Mosaic of Anguilla Harbor, St. Croix, U.S. Virgin Islands (NODC Accession 0086076)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  2. 2012 NOAA Ortho-rectified Color Mosaic of Seattle, Duwamish Waterway, and Lake Washington Ship Canal, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  3. 2014 NOAA Ortho-rectified Below Mean High Water Color Mosaic of Freeport, Texas: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  4. 2011 NOAA Ortho-rectified Mosaic of Texas: Integrated Ocean and Coastal Mapping Product (NODC Accession 0105604)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  5. 2014 NOAA Ortho-rectified Mean High Water Near- Infrared Mosaic of Cedar Key to Tarpon Springs, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  6. 2016 NOAA Ortho-rectified Mean Low Low Water Near-Infrared Mosaic of Cedar key to Tarpon Springs, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  7. 2015 NOAA NGS Ortho-rectified Near-Infrared Mosaic of Jacksonville Beach to Mosquito Lagoon, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  8. Design Criteria for DC Link Filters in a Synchronous Generator-Phase Controlled Rectifier-Filter-Load System

    National Research Council Canada - National Science Library

    Greseth, Gregory

    1999-01-01

    .... The proposed Navy DC Zonal Electrical Distribution System (DC ZEDS) being designed for the new DD-21 utilizes a rectified ac generator output which is filtered and stepped to usable voltages by local dc-dc converters...

  9. 2012 NOAA Ortho-rectified Color Mosaic of Tacoma and Gig Harbor, Washington: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  10. 2010 NOAA Ortho-rectified Mosaic from Color Aerial Imagery of MISSISSIPPI RIVER - BATON ROUGE TO LAPLACE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative of MISSISSIPPI RIVER -...

  11. 2010 NOAA Ortho-rectified Mosaic from Color Aerial Imagery of MISSISSIPPI RIVER - BATON ROUGE TO LAPLACE (NODC Accession 0074374)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative of MISSISSIPPI RIVER -...

  12. 2012 NOAA Ortho-rectified Mosaic of Laguna Madre / Arroyo Colorado, Texas: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  13. 2012 NOAA Ortho-rectified Near-Infrared MLLW Mosaic of Alabama: Bon Secour Bay and Weeks Bay NERR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  14. 2012 NOAA Ortho-rectified Color MLLW Mosaic of Alabama: Bon Secour Bay and Weeks Bay NERR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  15. 2013 NOAA Ortho-rectified Near Infrared Mean High Water Mosaic of South San Francisco Bay, California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  16. 2010 NOAA Near Infrared Ortho-rectified Mosaic of Louisiana: Mississippi River - Baton Rouge to Southwest Pass (NODC Accession 0104414)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  17. 2011 NOAA Ortho-rectified Mosaic of Hampton Harbor to Frost Point, New Hampshire (Mean High Water)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  18. 2011 NOAA Ortho-rectified Mosaic of Hampton Harbor to Frost Point, New Hampshire (Mean Lower Low Water)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  19. 2011 NOAA Ortho-rectified Near Infrared Mosaic of Hampton Harbor to Frost Point, New Hampshire (Mean Lower Low Water)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  20. Clinical Concentrations of Local Anesthetics Bupivacaine and Lidocaine Differentially Inhibit Human Kir2.x Inward Rectifier K+ Channels.

    Science.gov (United States)

    Nakahira, Kei; Oshita, Kensuke; Itoh, Masayuki; Takano, Makoto; Sakaguchi, Yoshiro; Ishihara, Keiko

    2016-04-01

    Inward rectifier K channels of the Kir2.x subfamily are widely expressed in neuronal tissues, controlling neuronal excitability. Previous studies reported that local anesthetics (LAs) do not affect Kir2 channels. However, the effects have not been studied at large concentrations used in regional anesthesia. This study used the patch-clamp technique to examine the effects of bupivacaine and lidocaine on Kir2.1, Kir2.2, and Kir2.3 channels expressed in human embryonic kidney 293 cells. When applied extracellularly in whole-cell recordings, both LAs inhibited Kir2.x currents in a voltage-independent manner. Inhibition with bupivacaine was slow and irreversible, whereas that with lidocaine was fast and reversible. Kir2.3 displayed a greater sensitivity to bupivacaine than Kir2.1 and Kir2.2 (50% inhibitory concentrations at approximately 5 minutes, 0.6 vs 8-10 mM), whereas their sensitivities to lidocaine were similar (50% inhibitory concentrations, 1.5-2.7 mM). Increases in the charged/neutral ratio of the LAs at an acidic extracellular pH attenuated their inhibitory effects, and a permanently charged lidocaine derivative QX-314 exhibited no effects when applied extracellularly. Inside-out experiments demonstrated that inhibition of Kir2.1 with cytoplasmic lidocaine and QX-314 was rapid and reversible, whereas that induced by bupivacaine was slow and irreversible. Furthermore, dose-inhibition relations for the charged form of bupivacaine and lidocaine obtained at different cytoplasmic pHs could be approximated by a single relation for each LA. The results indicate that both LAs at clinical concentrations equilibrated rapidly with the intracellular milieu, differentially inhibiting Kir2.x channel function from the cytoplasmic side.

  1. Histamine facilitates GABAergic transmission in the rat entorhinal cortex: Roles of H1 and H2 receptors, Na+ -permeable cation channels, and inward rectifier K+ channels.

    Science.gov (United States)

    Cilz, Nicholas I; Lei, Saobo

    2017-05-01

    In the brain, histamine (HA) serves as a neuromodulator and a neurotransmitter released from the tuberomammillary nucleus (TMN). HA is involved in wakefulness, thermoregulation, energy homeostasis, nociception, and learning and memory. The medial entorhinal cortex (MEC) receives inputs from the TMN and expresses HA receptors (H1 , H2 , and H3 ). We investigated the effects of HA on GABAergic transmission in the MEC and found that HA significantly increased the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) with an EC50 of 1.3 µM, but failed to significantly alter sIPSC amplitude. HA-induced increases in sIPSC frequency were sensitive to tetrodotoxin (TTX), required extracellular Ca2+ , and persisted when GDP-β-S, a G-protein inactivator, was applied postsynaptically via the recording pipettes, indicating that HA increased GABA release by facilitating the excitability of GABAergic interneurons in the MEC. Recordings from local MEC interneurons revealed that HA significantly increased their excitability as determined by membrane depolarization, generation of an inward current at -65 mV, and augmentation of action potential firing frequency. Both H1 and H2 receptors were involved in HA-induced increases in sIPSCs and interneuron excitability. Immunohistochemical staining showed that both H1 and H2 receptors are expressed on GABAergic interneurons in the MEC. HA-induced depolarization of interneurons involved a mixed ionic mechanism including activation of a Na+ -permeable cation channel and inhibition of a cesium-sensitive inward rectifier K+ channel, although HA also inhibited the delayed rectifier K+ channels. Our results may provide a cellular mechanism, at least partially, to explain the roles of HA in the brain. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Novel low harmonics 3-phase rectifiers for efficient motor systems; Novel low harmonics 3-phase rectifiers for efficient motor systems. Konzeptstudie - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Pietkiewicz, A.; Melly, S.; Tucker, A.; Haeberle, N. [Schaffner EMV AG, Luterbach (Switzerland); Biner, H.-P. [Haute Ecole Specialisee de Suisse occidentale, HES-SO Valais, Sion (Switzerland)

    2010-07-15

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a concept study made concerning novel low harmonics 3-phase rectifiers for efficient motor systems. The harmonic distortions which are produced by these systems are discussed and ways of minimising them are examined. The authors discuss novel, passive, multi-pulse current splitters that are considered to be cost efficient, compact and highly-reliable harmonics mitigation concepts for three-phase loads. According to the authors, functional prototypes for a nominal load of 4 kW proved, in laboratory tests, the outstanding properties of multi-pulse current splitters with respect to harmonics cancellation and robustness against voltage asymmetry. The design process, prototype construction and application tests are discussed, as are energy-saving potentials and marketing aspects.

  3. Delayed Orgasm and Anorgasmia

    OpenAIRE

    JENKINS, Lawrence C.; Mulhall, John P.

    2015-01-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies; which include: medications, penile sensation loss, endocrinopathies, penile hyperstimulation and psychological etiologies, amongst others. Unfortunately, ...

  4. 4-Aminopyridine causes apoptosis and blocks an outward rectifier K+ channel in malignant astrocytoma cell lines.

    Science.gov (United States)

    Chin, L S; Park, C C; Zitnay, K M; Sinha, M; DiPatri, A J; Perillán, P; Simard, J M

    1997-04-15

    Among the ion channels and pumps activated by growth factor stimulation, K+ channels have been implicated in the growth and proliferation of several cancer cell lines. The role of these channels in central nervous system tumors, however, has not been described. This study used the malignant astrocytoma cell lines U87 and A172. 4-Aminopyridine (4-AP) inhibition of proliferation was dose dependent, and assessment using a TUNEL in situ assay revealed that apoptosis occurred in U87 cells with wild-type p53 but not in A172 cells with mutant p53 (24-hr incubation with mM 4-AP). In patch clamp experiments, we identified two types of K+ currents in both cell lines, a charybdotoxin-sensitive Ca2(+)-activated K+ channel and a 4-AP-sensitive outward rectifier K+ current. The outward rectifier current was blocked by 4-AP in a dose-dependent manner, with half-maximal block occurring at 3.9 mM. The blocking effect of 4 mM 4-AP was noticeable at potentials as low as -65 mV and was statistically significant at -60 mV and above, suggesting that 4-AP-sensitive current is active at physiological potentials. By contrast, charybdotoxin (1 microM) and tetraethylammonium. Cl (2 mM) blocked the Ca2(+)-activated K+ channel in both cell lines but had no appreciable effect on cell growth. Our findings reveal that 4-AP inhibits proliferation and the outward rectifier K+ channel in both U87 and A172 cells. More studies are needed, however, to describe the mechanism by which K+ channels influence proliferation and induce apoptosis.

  5. Achievement of digital control technology on high-power silicon controlled rectifier

    Science.gov (United States)

    Gao, Yinhan; Sun, Qiang; Liu, Changying

    2008-10-01

    To fulfill the need of experimental DC supply of subway inverter, this paper designs and develops a set of rectifier system of 160kW, output voltage can be adjusted from 500V to 900V. This article uses SCR as main switches, the trigger circuit adopts digital trigger circuit, the control of whole system is achieved by DSP. The main control method is digital PI, which used to control the output DC voltage to be dynamically stable. The main circuit parameters and control method are simulated by MATLAB/Simulink. The results validate the system design.

  6. Designing single phase Current-Programmed-Controlled rectifiers by harmonic currents

    DEFF Research Database (Denmark)

    Andersen, Gert Karmisholt; Blaabjerg, Frede

    2002-01-01

    The grid current harmonics of a Current-Programmed-Controlled (CPC) pfc rectifier strongly depends on the choice of switching frequency and switching inductance. This paper describes a new simple and vert fast method to calculate the grid current of a CPC controlled pfc converter. The method...... includes ramp compensation, different command current waveforms and the influence of the filter. One method show how the product of the inductance and the switching frequency determines the maximum power level the complies with IEC-61000-3-2. Design examples illustrate the possibilities of the presented...

  7. Single Phase Current-Source Active Rectifier for Traction: Control System Design and Practical Problems

    Directory of Open Access Journals (Sweden)

    Jan Michalik

    2006-01-01

    Full Text Available This research has been motivated by industrial demand for single phase current-source active rectifier dedicated for reconstruction of older types of dc machine locomotives. This paper presents converters control structure design and simulations. The proposed converter control is based on the mathematical model and due to possible interaction with railway signaling and required low switching frequency employs synchronous PWM. The simulation results are verified by experimental tests performed on designed laboratory prototype of power of 7kVA

  8. High-performance digital triggering system for phase-controlled rectifiers

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, R.E.

    1983-01-01

    The larger power supplies used to power accelerator magnets are most commonly polyphase rectifiers using phase control. While this method is capable of handling impressive amounts of power, it suffers from one serious disadvantage, namely that of subharmonic ripple. Since the stability of the stored beam depends to a considerable extent on the regulation of the current in the bending magnets, subharmonic ripple, especially that of low frequency, can have a detrimental effect. At the NSLS, we have constructed a 12-pulse, phase control system using digital signal processing techniques that essentially eliminates subharmonic ripple.

  9. High Efficiency Three-phase Power Factor Correction Rectifier using Wide Band-Gap Devices

    DEFF Research Database (Denmark)

    Kouchaki, Alireza

    Improving the conversion efficiency of power factor correction (PFC) rectifiers has become compelling due to their wide applications such as adjustable speed drives, uninterruptible power supplies (UPS), and battery chargers for electric vehicles (EVs). The attention to PFCs has increased even more...... quality. To have similar harmonic performance the PI controller needs larger filter in comparison with the PR controller. This eventually ends up with lower efficiency of the converter with the PI current controller. In this thesis, two sets of experiments are carried out: • Verification of the designed...

  10. Creation of a sharper focus by using a rectified TEM p0 beam

    Science.gov (United States)

    Hasnaoui, A.; Bencheikh, A.; Fromager, M.; Cagniot, E.; Aït-Ameur, K.

    2011-03-01

    The superresolution technique is usually used in optical imaging for its ability to make the central diffractive spot smaller than the Airy spot. In this paper, we apply the superresolution technique for transforming a symmetrical TEMp0 Laguerre-Gauss beam into a Gaussian intensity distribution in the plane of a converging lens. The beam shaping is achieved by an annular binary Diffractive Optical Element having a transmittance, alternatively equal to -1 or + 1, modelled on the p light rings of the incident beam. It is observed that the rectified TEM30 beam at focus has a focal volume 170 times smaller than that of a Gaussian beam.

  11. Robust and reliable rectifier based on electronic inductor with improved performance

    DEFF Research Database (Denmark)

    Singh, Yash Veer; Rasmussen, Peter Omand; Andersen, Torben Ole

    2014-01-01

    harmonic distortions (THDs) of the ac mains current in a three phase diode bridge rectifier. The ESI reduces the low frequency ripples and controls the intermediate dc-link voltage to a dc value and peak value of the mains current also reduces. In case of an inverter connected to the output......Reliability of a power converter depends on voltage and current stresses seen by power semiconductor devices during transient and steady state operation of the power converter. Electronic smoothing inductor (ESI) is an attractive circuit topology to improve power factor and to reduce the total...

  12. Converter-flux-based current control of voltage source PWM rectifiers - analysis and implementation

    Energy Technology Data Exchange (ETDEWEB)

    Poellaenen, R.

    2003-07-01

    Pulsewidth-modulated (PWM) rectifier technology is increasingly used in industrial applications like variable-speed motor drives, since it offers several desired features such as sinusoidal input currents, controllable power factor, bidirectional power flow and high quality DC output voltage. To achieve these features, however, an effective control system with fast and accurate current and DC voltage responses is required. From various control strategies proposed to meet these control objectives, in most cases the commonly known principle of the synchronous-frame current vector control along with some space-vector PWM scheme have been applied. Recently, however, new control approaches analogous to the well-established direct torque control (DTC) method for electrical machines have also emerged to implement a high-performance PWM rectifier. In this thesis the concepts of classical synchronous-frame current control and DTC-based PWM rectifier control are combined and a new converter-flux-based current control (CFCC) scheme is introduced. To achieve sufficient dynamic performance and to ensure a stable operation, the proposed control system is thoroughly analysed and simple rules for the controller design are suggested. Special attention is paid to the estimation of the converter flux, which is the key element of converter-flux-based control. Discrete-time implementation is also discussed. Line-voltage-sensorless reactive reactive power control methods for the L- and LCL-type line filters are presented. For the L-filter an open-loop control law for the d-axis current reference is proposed. In the case of the LCL-filter the combined open-loop control and feedback control is proposed. The influence of the erroneous filter parameter estimates on the accuracy of the developed control schemes is also discussed. A new zero vector selection rule for suppressing the zero-sequence current in parallel-connected PWM rectifiers is proposed. With this method a truly standalone and

  13. Energy Saving in Three-Phase Diode Rectifiers Using EI Technique with Adjustable Switching Frequency Scheme

    DEFF Research Database (Denmark)

    Davari, Pooya; Zare, Firuz; Yang, Yongheng

    2016-01-01

    A front-end rectifier can significantly impact a power electronics system performance and efficiency for applications such as motor drive where the system commonly operates under partial loading conditions. This paper proposes an adjustable switching frequency scheme using an electronic inductor...... technique to improve the energy saving of the system operating at partial loading. In the proposed solution, the switching frequency is adjusted based on the loading conditions, and thus maintains the system performance both in terms of switching losses and harmonic distortion. The obtained simulation...

  14. Enhancing the photoelectric effect with a potential-programmed molecular rectifier.

    Science.gov (United States)

    Imaoka, Takane; Ueda, Hiroaki; Yamamoto, Kimihisa

    2012-05-23

    Dendrimer-based electron rectifiers were applied to photoconducting devices. A remarkable enhancement of the photocurrent response was observed when a zinc porphyrin as the photosensitizer was embedded in the dendritic phenylazomethine (DPA) architecture. The dendrimer-based sensitizer exhibited a 20-fold higher current response than the non-dendritic zinc porphyrin. In sharp contrast, a similar application of the dendrimer with poly(vinylcarbazole) as the electron donor resulted in a decreased response. This is consistent with the idea that the DPA facilitates electron transfer from the core to its periphery along a potential gradient, as predicted by density functional theory calculations.

  15. Rectifying performance and negative differential behavior in graphite—chain—carbon nanotube junctions

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Ming [Department of Mechanical Engineering, University of Wisconsin, Milwaukee, Wisconsin 53211 (United States); School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114 (China); Li, Jiangfan [School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114 (China); Liew, K. M., E-mail: kmliew@cityu.edu.hk [Department of Civil and Architectural Engineering, City University of Hong Kong, Kowloon (Hong Kong); Yuan, Chris, E-mail: cyuan@uwm.edu [Department of Mechanical Engineering, University of Wisconsin, Milwaukee, Wisconsin 53211 (United States)

    2014-01-13

    In this paper, the (5, 5) capped carbon nanotubes (CNTs) in contact with different lengths of sp monoatomic chains grown on the surface of graphite substrate are fabricated and its electronic transport properties sandwiched between CNT and graphite electrodes are investigated. The first-principles calculations based on nonequilibrium Green's function in combination with density-functional theory show that their rectifying performance and negative differential resistance behavior are observed under very low biases and obviously are enhanced when the length increases. From our analysis, the charge transfer, transmission spectra, projected density of states and evolutions of molecular orbitals are responsible for these phenomena.

  16. US Mains Stacked Very High Frequency Self-oscillating Resonant Power Converter with Unified Rectifier

    DEFF Research Database (Denmark)

    Pedersen, Jeppe Arnsdorf; Madsen, Mickey Pierre; Mønster, Jakob Døllner

    2016-01-01

    This paper describes a Very High Frequency (VHF) converter made with three Class-E inverters and a single ClassDE rectifier. The converter is designed for the US mains (120 V, 60 Hz) and can deliver 9 W to a 60 V LED. The converter has a switching frequency of 37 MHz and achieves an efficiency...... of 89.4%. With VHF converters the power density can be improved and the converter described in this paper has a power density of 2.14 W/cm3. The power factor (PF) requrements of mains connected equepment is fulfilled with a power factor of 0.96....

  17. Universal Voltage Conveyor and Current Conveyor in Fast Full-Wave Rectifier

    Directory of Open Access Journals (Sweden)

    Josef Burian

    2012-12-01

    Full Text Available This paper deals about the design of a fast voltage-mode full-wave rectifier, where universal voltage conveyor and second-generation current conveyor are used as active elements. Thanks to the active elements, the input and output impedance of the non-linear circuit is infinitely high respectively zero in theory. For the rectification only two diodes and three resistors are required as passive elements. The performance of the circuit is shown on experimental measurement results showing the dynamic range, time response, frequency dependent DC transient value and RMS error for different values of input voltage amplitudes.

  18. Blue LEDs, UV photodiodes and high-temperature rectifiers in 6H-SiC

    Science.gov (United States)

    Edmond, John A.; Kong, Hua-Shuang; Carter, Calvin H.

    1993-04-01

    Single junction devices in silicon carbide have been developed for use as blue LEDs, UV photodiodes and high- temperature rectifiers. As a light emitter, 6H-SiC junctions can be tailored to emit light across the visible spectrum. The most widely commercialized device is the blue LED. Over the past two years, the quantum efficiency of the Cree blue LED has increased significantly. The devices emit light with a peak wavelength of 470 nm with a spectral halfwidth of ∼70 nm. The optical power output is typically between 12 and 18 μW for a forward current of 20 mA at 3 V. This represents a power efficiency of ∼0.02-0.03%. In addition to blue emission, the energy bandgap of ∼3.0 eV allows for inherently low dark currents and high quantum efficiencies for ultraviolet photodiode detectors made in 6H-SiC, even at high temperatures. These devices typically exhibit a quantum efficiency of 80-100% and peak response of ∼250-280 nm. These characteristics are maintained to at least 623 K. The dark current density at -1.0 V and 473 K is ∼10 -11 A/cm 2. This corresponds to an extrapolated room temperature current density of ∼2 × 10 -17 A/cm 2 at -1.0 V. Rectifiers with blocking voltages as high as ∼1400 V and a forward current rating of 400 mA at ∼3.0 V have been fabricated. For a 710 V rectifier, the reverse bias leakage current density at 200 V is shown to increase from ∼10 -9 to ∼10 -7 A/cm 2 from 300 to 673 K, respectively. The reverse bias breakdown appears to occur via avalanche multiplication processes exhibiting a sharp knee at breakdown. For a ∼1400 V rectifier, the reverse bias leakage current at 1375 V is less than 1 μA at room temperature.

  19. Control of a PWM Rectifier with Extended Functions in a Signal Digital Processor

    Directory of Open Access Journals (Sweden)

    C. Núñez–Gutiérrez

    2009-01-01

    Full Text Available This work presents the application of a digital signal processor (DSP for the control of a three–phase PWM rectifier for industrial applications, to which are extended their functions to have capacity to compensate voltage sags. The study stands out the advantages that the DSP offers to control, based on the system transformation from fix reference frame to synchronous reference frame (D–Q theory and classical controllers. The analysis of the system is presented, as well as simulation and experimental results to validate the operation of the DSP as system element controller.

  20. Synergetic activation of outwardly rectifying Cl− currents by hypotonic stress and external Ca2+ in murine osteoclasts

    Science.gov (United States)

    Sakai, Hiromu; Nakamura, Fusao; Kuno, Miyuki

    1999-01-01

    An outwardly rectifying Cl− (ORCl) current of murine osteoclasts was activated by hypotonic stimulation. The current was characterized by rapid activation, little inactivation, strong outward rectification, blockage by DIDS and permeability to organic acids (pyruvate and glutamate). The hypotonically activated ORCl current was inhibited by intracellular dialysis with an ATP-free pipette solution, but not by replacement of ATP with a poorly hydrolysable ATP analogue adenosine 5′-O-(3-thiotriphosphate). The current amplitude was reduced when intracellular alkalinity increased over the pH range 6.6–8.0. Intracellular application of cytochalasin D occasionally activated the ORCl current without hypotonic stress, but inhibited activation of the ORCl current by hypotonic stimulation. The hypotonically activated ORCl current was unaffected by a non-actin-depolymerizing cytochalasin, chaetoglobosin C, but partially inhibited by deoxyribonuclease I. Removal of extracellular Ca2+ inhibited activation of the ORCl current by hypotonic shock, but did not reduce the current once activated. The hypotonically activated ORCl current was partially decreased by intracellular dialysis with 20 mm EGTA. With 10 mm Ca2+ in the extracellular medium, the ORCl current was activated in response to more minor decreases in osmolarity than with 1 mm Ca2+. The increased sensitivity to hypotonicity was mimicked by increasing the intracellular Ca2+ level (pCa 6.5). These results suggest that hypotonic stimulation and a rise in the extracellular Ca2+ level synergistically activate the ORCl channel of murine osteoclasts, and that the activating process is modified by multiple intracellular factors (pH, ATP and actin cytoskeletal organization). PMID:9925886

  1. ORM-10103, a novel specific inhibitor of the Na+/Ca2+ exchanger, decreases early and delayed afterdepolarizations in the canine heart.

    Science.gov (United States)

    Jost, N; Nagy, N; Corici, C; Kohajda, Z; Horváth, A; Acsai, K; Biliczki, P; Levijoki, J; Pollesello, P; Koskelainen, T; Otsomaa, L; Tóth, A; Papp, J Gy; Varró, A; Virág, L

    2013-10-01

    At present there are no small molecule inhibitors that show strong selectivity for the Na(+) /Ca(2+) exchanger (NCX). Hence, we studied the electrophysiological effects of acute administration of ORM-10103, a new NCX inhibitor, on the NCX and L-type Ca(2+) currents and on the formation of early and delayed afterdepolarizations. Ion currents were recorded by using a voltage clamp technique in canine single ventricular cells, and action potentials were obtained from canine and guinea pig ventricular preparations with the use of microelectrodes. ORM-10103 significantly reduced both the inward and outward NCX currents. Even at a high concentration (10 μM), ORM-10103 did not significantly change the L-type Ca(2+) current or the maximum rate of depolarization (dV/dtmax ), indicative of the fast inward Na(+) current. At 10 μM ORM-10103 did not affect the amplitude or the dV/dtmax of the slow response action potentials recorded from guinea pig papillary muscles, which suggests it had no effect on the L-type Ca(2+) current. ORM-10103 did not influence the Na(+) /K(+) pump or the main K(+) currents of canine ventricular myocytes, except the rapid delayed rectifier K(+) current, which was slightly diminished by the drug at 3 μM. The amplitudes of pharmacologically- induced early and delayed afterdepolarizations were significantly decreased by ORM-10103 (3 and 10 μM) in a concentration-dependent manner. ORM-10103 is a selective inhibitor of the NCX current and can abolish triggered arrhythmias. Hence, it has the potential to be used to prevent arrhythmogenic events. © 2013 The British Pharmacological Society.

  2. Comparison between phase-shift full-bridge converters with noncoupled and coupled current-doubler rectifier.

    Science.gov (United States)

    Tsai, Cheng-Tao; Su, Jye-Chau; Tseng, Sheng-Yu

    2013-01-01

    This paper presents comparison between phase-shift full-bridge converters with noncoupled and coupled current-doubler rectifier. In high current capability and high step-down voltage conversion, a phase-shift full-bridge converter with a conventional current-doubler rectifier has the common limitations of extremely low duty ratio and high component stresses. To overcome these limitations, a phase-shift full-bridge converter with a noncoupled current-doubler rectifier (NCDR) or a coupled current-doubler rectifier (CCDR) is, respectively, proposed and implemented. In this study, performance analysis and efficiency obtained from a 500 W phase-shift full-bridge converter with two improved current-doubler rectifiers are presented and compared. From their prototypes, experimental results have verified that the phase-shift full-bridge converter with NCDR has optimal duty ratio, lower component stresses, and output current ripple. In component count and efficiency comparison, CCDR has fewer components and higher efficiency at full load condition. For small size and high efficiency requirements, CCDR is relatively suitable for high step-down voltage and high efficiency applications.

  3. Delays in thick targets

    CERN Document Server

    Bennett, J R J

    2002-01-01

    The delays in the emission of radioactive particles from a thick target bombarded by high-energy protons is discussed in relation to the basic physical processes of diffusion and effusion through the target and ioniser. The delay time, relative to the decay time, is crucial to the efficiency of particle release at the exit of the ioniser. The principles of minimizing the delay times are discussed with reference to a mathematical model of the process, and some experimental examples are given.

  4. Delayed orgasm and anorgasmia.

    Science.gov (United States)

    Jenkins, Lawrence C; Mulhall, John P

    2015-11-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies, which include medications, penile sensation loss, endocrinopathies, penile hyperstimulation, and psychological etiologies. Unfortunately, there are no excellent pharmacotherapies for delayed orgasm/anorgasmia, and treatment revolves largely around addressing potential causative factors and psychotherapy. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  5. An isolated bridgeless AC-DC PFC converter using a LC resonant voltage doubler rectifier

    Science.gov (United States)

    Lee, Sin-woo; Do, Hyun-Lark

    2016-12-01

    This paper proposed an isolated bridgeless AC-DC power factor correction (PFC) converter using a LC resonant voltage doubler rectifier. The proposed converter is based on isolated conventional single-ended primary inductance converter (SEPIC) PFC converter. The conduction loss of rectification is reduced than a conventional one because the proposed converter is designed to eliminate a full-bridge rectifier at an input stage. Moreover, for zero-current switching (ZCS) operation and low voltage stresses of output diodes, the secondary of the proposed converter is designed as voltage doubler with a LC resonant tank. Additionally, an input-output electrical isolation is provided for safety standard. In conclusion, high power factor is achieved and efficiency is improved. The operational principles, steady-state analysis and design equations of the proposed converter are described in detail. Experimental results from a 60 W prototype at a constant switching frequency 100 kHz are presented to verify the performance of the proposed converter.

  6. Chemical profile of sugarcane spirits produced by double distillation methodologies in rectifying still

    Directory of Open Access Journals (Sweden)

    André Ricardo Alcarde

    2011-06-01

    Full Text Available The objective of this study was to determine the chemical profile of sugarcane spirits produced by different double distillation methodologies in rectifying still. Fermented sugarcane juice was distilled in rectifying still according to three double distillation methodologies: the methodology used for cognac production; the methodology used for whisky production; and the 10-80-10 percentage composition methodology, referring to the volumes of head, heart and tail of the distillate fractions from the second distillation. For comparison purposes, a simple distilled spirit was also produced. The distillates were analyzed for concentrations of ethanol, copper, volatile acidity, furfural and hydroxymethylfurfural, aldehydes, esters, methanol and higher alcohols. The spirits were also evaluated on the sensory attributes of aroma, taste and preference. Compared to simple distillation, double distillation improved the chemical quality of the spirits, since it has reduced the concentrations of acids, aldehydes, esters, methanol, higher alcohols and, consequently, their coefficient of congeners. Regardless of the methodology employed, the double distillation improved the sensory quality of the spirits since they obtained higher sensory acceptance in relation to spirits produced by simple distillation. Among double distilled spirits, the one produced according to whisky methodology obtained the best scores from appraisers on the aroma and flavor parameters and it was also the most preferred.

  7. Power spectrum of the rectified EMG: when and why is rectification beneficial for identifying neural connectivity?

    Science.gov (United States)

    Negro, Francesco; Keenan, Kevin; Farina, Dario

    2015-06-01

    Objective. The identification of common oscillatory inputs to motor neurons in the electromyographic (EMG) signal power spectrum is often preceded by EMG rectification for enhancing the low-frequency oscillatory components. However, rectification is a nonlinear operator and its influence on the EMG signal spectrum is not fully understood. In this study, we aim at determining when EMG rectification is beneficial in the study of oscillatory inputs to motor neurons. Approach. We provide a full mathematical description of the power spectrum of the rectified EMG signal and the influence of the average shape of the motor unit action potentials on it. We also provide a validation of these theoretical results with both simulated and experimental EMG signals. Main results. Simulations using an advanced computational model and experimental results demonstrated the accuracy of the theoretical derivations on the effect of rectification on the EMG spectrum. These derivations proved that rectification is beneficial when assessing the strength of low-frequency (delta and alpha bands) common synaptic inputs to the motor neurons, when the duration of the action potentials is short, and when the level of cancellation is relatively low. On the other hand, rectification may distort the estimation of common synaptic inputs when studying higher frequencies (beta and gamma), in a way dependent on the duration of the action potentials, and may introduce peaks in the coherence function that do not correspond to physiological shared inputs. Significance. This study clarifies the conditions when rectifying the surface EMG is appropriate for studying neural connectivity.

  8. Simulation and Analysis of Three-Phase Rectifiers for Aerospace Power Applications

    Science.gov (United States)

    Truong, Long V.; Birchenough, Arthur G.

    2004-01-01

    Due to the nature of planned planetary missions, fairly large advanced power systems are required for the spacecraft. These future high power spacecrafts are expected to use dynamic power conversion systems incorporating high speed alternators as three-phase AC electrical power source. One of the early design considerations in such systems is the type of rectification to be used with the AC source for DC user loads. This paper address the issues involved with two different rectification methods, namely the conventional six and twelve pulses. Two circuit configurations which involved parallel combinations of the six and twelve-pulse rectifiers were selected for the simulation. The rectifier s input and output power waveforms will be thoroughly examined through simulations. The effects of the parasitic load for power balancing and filter components for reducing the ripple voltage at the DC loads are also included in the analysis. Details of the simulation circuits, simulation results, and design examples for reducing risk from damaging of spacecraft engines will be presented and discussed.

  9. Rectifier Fault Diagnosis and Fault Tolerance of a Doubly Fed Brushless Starter Generator

    Directory of Open Access Journals (Sweden)

    Liwei Shi

    2015-01-01

    Full Text Available This paper presents a rectifier fault diagnosis method with wavelet packet analysis to improve the fault tolerant four-phase doubly fed brushless starter generator (DFBLSG system reliability. The system components and fault tolerant principle of the high reliable DFBLSG are given. And the common fault of the rectifier is analyzed. The process of wavelet packet transforms fault detection/identification algorithm is introduced in detail. The fault tolerant performance and output voltage experiments were done to gather the energy characteristics with a voltage sensor. The signal is analyzed with 5-layer wavelet packets, and the energy eigenvalue of each frequency band is obtained. Meanwhile, the energy-eigenvalue tolerance was introduced to improve the diagnostic accuracy. With the wavelet packet fault diagnosis, the fault tolerant four-phase DFBLSG can detect the usual open-circuit fault and operate in the fault tolerant mode if there is a fault. The results indicate that the fault analysis techniques in this paper are accurate and effective.

  10. From bidirectional rectifier to polarity-controllable transistor in black phosphorus by dual gate modulation

    Science.gov (United States)

    Wang, Guocai; Bao, Lihong; Ma, Ruisong; Pei, Tengfei; Zhang, Yu-Yang; Wu, Liangmei; Zhou, Zhang; Yang, Haifang; Li, Junjie; Gu, Changzhi; Du, Shixuan; Pantelides, Sokrates T.; Gao, Hong-Jun

    2017-06-01

    In complementary metal oxide semiconductor (CMOS) technology, well-defined unipolar transport in field-effect transistors (FETs) is a basic requirement for logic operations, which can be realized by controllable doping of the semiconductor with electrons (n-type) or holes (p-type). However, recent demonstration of polarity controllable transistors in 2D semiconductors provides a flexible way in circuit design with increased circuit integration density. Here we demonstrate the conversion of a bidirectional rectifier to a polarity-controllable transistor in black phosphorus (BP) by dual gate modulation. Electrical characterization of the BP bidirectional rectifier reveals a current rectification of ~35 at room temperature that increases to ~350 upon lowering the temperature to 110 K. Employing cross-linked PMMA as a top gate and combining it together with the global back gate of the SiO2 substrate, well-defined unipolar transport (n- or p-type) in BP could get accessed. This successful realization of polarity-controllable transistor in BP provides an alternative design for development of BP logic electronics.

  11. Simulation study of a rectifying bipolar ion channel: Detailed model versus reduced model

    Directory of Open Access Journals (Sweden)

    Z. Ható

    2016-02-01

    Full Text Available We study a rectifying mutant of the OmpF porin ion channel using both all-atom and reduced models. The mutant was created by Miedema et al. [Nano Lett., 2007, 7, 2886] on the basis of the NP semiconductor diode, in which an NP junction is formed. The mutant contains a pore region with positive amino acids on the left-hand side and negative amino acids on the right-hand side. Experiments show that this mutant rectifies. Although we do not know the structure of this mutant, we can build an all-atom model for it on the basis of the structure of the wild type channel. Interestingly, molecular dynamics simulations for this all-atom model do not produce rectification. A reduced model that contains only the important degrees of freedom (the positive and negative amino acids and free ions in an implicit solvent, on the other hand, exhibits rectification. Our calculations for the reduced model (using the Nernst-Planck equation coupled to Local Equilibrium Monte Carlo simulations reveal a rectification mechanism that is different from that seen for semiconductor diodes. The basic reason is that the ions are different in nature from electrons and holes (they do not recombine. We provide explanations for the failure of the all-atom model including the effect of all the other atoms in the system as a noise that inhibits the response of ions (that would be necessary for rectification to the polarizing external field.

  12. Structural basis of control of inward rectifier Kir2 channel gating by bulk anionic phospholipids

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sun-Joo; Ren, Feifei; Zangerl-Plessl, Eva-Maria; Heyman, Sarah; Stary-Weinzinger, Anna; Yuan, Peng; Nichols, Colin G. (WU-MED); (Vienna)

    2016-08-15

    Inward rectifier potassium (Kir) channel activity is controlled by plasma membrane lipids. Phosphatidylinositol-4,5-bisphosphate (PIP2) binding to a primary site is required for opening of classic inward rectifier Kir2.1 and Kir2.2 channels, but interaction of bulk anionic phospholipid (PL-) with a distinct second site is required for high PIP2sensitivity. Here we show that introduction of a lipid-partitioning tryptophan at the second site (K62W) generates high PIP2sensitivity, even in the absence of PL-. Furthermore, high-resolution x-ray crystal structures of Kir2.2[K62W], with or without added PIP2(2.8- and 2.0-Å resolution, respectively), reveal tight tethering of the C-terminal domain (CTD) to the transmembrane domain (TMD) in each condition. Our results suggest a refined model for phospholipid gating in which PL-binding at the second site pulls the CTD toward the membrane, inducing the formation of the high-affinity primary PIP2site and explaining the positive allostery between PL-binding and PIP2sensitivity.

  13. Three-dimensional crossbar arrays of self-rectifying Si/SiO2/Si memristors

    Science.gov (United States)

    Li, Can; Han, Lili; Jiang, Hao; Jang, Moon-Hyung; Lin, Peng; Wu, Qing; Barnell, Mark; Yang, J. Joshua; Xin, Huolin L.; Xia, Qiangfei

    2017-06-01

    Memristors are promising building blocks for the next-generation memory and neuromorphic computing systems. Most memristors use materials that are incompatible with the silicon dominant complementary metal-oxide-semiconductor technology, and require external selectors in order for large memristor arrays to function properly. Here we demonstrate a fully foundry-compatible, all-silicon-based and self-rectifying memristor that negates the need for external selectors in large arrays. With a p-Si/SiO2/n-Si structure, our memristor exhibits repeatable unipolar resistance switching behaviour (105 rectifying ratio, 104 ON/OFF) and excellent retention at 300 °C. We further build three-dimensinal crossbar arrays (up to five layers of 100 nm memristors) using fluid-supported silicon membranes, and experimentally confirm the successful suppression of both intra- and inter-layer sneak path currents through the built-in diodes. The current work opens up opportunities for low-cost mass production of three-dimensional memristor arrays on large silicon and flexible substrates without increasing circuit complexity.

  14. Odd harmonic high order repetitive control of single-phase pmw rectifiers: varying frequency operation

    Directory of Open Access Journals (Sweden)

    Germán A. Ramos-Fuentes

    2016-01-01

    Full Text Available Controlled rectifiers are electronic power devices aimed at reducing the harmonic pollution in electrical networks caused by the power conversion process. The main goal is to obtain a sinusoidal shape current in phase with the voltage network. Although Proportional Integral controllers are widely used for the current control loop, they do not provide high performance results. On the contrary, Resonant and Repetitive Control are techniques with remarkable results on this area. However, their main drawback is the lost of performance due to frequency changes in the exogenous signal. In this work, the implementation of an Odd Harmonic High Order Repetitive Controller is proposed for the rectifier current loop. The odd harmonic characteristic of this compensator makes possible to obtain a computational burden that is very similar to the one obtained by conventional repetitive controllers with the advantage of increase the robustness against frequency variations. Experimental results show the high performance obtained even when the network frequency does not match the designed nominal frequency

  15. Optimal Design of a Resonance-Based Voltage Boosting Rectifier for Wireless Power Transmission.

    Science.gov (United States)

    Lim, Jaemyung; Lee, Byunghun; Ghovanloo, Maysam

    2018-02-01

    This paper presents the design procedure for a new multi-cycle resonance-based voltage boosting rectifier (MCRR) capable of delivering a desired amount of power to the load (PDL) at a designated high voltage (HV) through a loosely-coupled inductive link. This is achieved by shorting the receiver (Rx) LC-tank for several cycles to harvest and accumulate the wireless energy in the RX inductor before boosting the voltage by breaking the loop and transferring the energy to the load in a quarter cycle. By optimizing the geometries of the transmitter (Tx) and Rx coils and the number of cycles, N, for energy harvesting, through an iterative design procedure, the MCRR can achieve the highest PDL under a given set of design constraints. Governing equations in the MCRR operation are derived to identify key specifications and the design guidelines. Using an exemplary set of specs, the optimized MCRR was able to generate 20.9 VDC across a 100 kΩ load from a 1.8 Vp, 6.78 MHz sinusoid input in the ISM-band at a Tx/Rx coil separation of 1.3 cm, power transfer efficiency (PTE) of 2.2%, and N = 9 cycles. At the same coil distance and loading, coils optimized for a conventional half-wave rectifier (CHWR) were able to reach only 13.6 VDC from the same source.

  16. Peak current mode control of three-phase boost rectifiers in discontinuous conduction mode for small wind power generators

    Energy Technology Data Exchange (ETDEWEB)

    Carranza, O. [Escuela Superior de Computo, Instituto Politecnico Nacional (Mexico); Garcera, G.; Figueres, E. [Grupo de Sistemas Electronicos Industriales del Departamento de Ingenieria Electronica, Universidad Politecnica de Valencia (Spain); Gonzalez, L.G. [Departamento de Ingenieria Electronica y Comunicaciones, Universidad de los Andes (Venezuela)

    2010-08-15

    This paper presents a peak current mode control scheme of a boost rectifier with low distortion of the input current for wind power systems based on permanent magnet synchronous generators with variable speed operation. The three-phase boost rectifier is operated in discontinuous conduction mode (DCM), and power factor correction techniques are applied. It is shown that the DCM operation significantly reduces the total harmonic distortion of the currents in the permanent magnet synchronous generator, increasing the power factor of the system, so that the vibrations and mechanical stress of the generator are minimized. The characteristics of the DCM boost rectifier are studied considering: (1) the series resistance of the inductors; (2) the modeling and adjustment of peak current mode control yielding a stable loop; (3) the design of an input filter that reduces the switching noise in the currents of the generator. (author)

  17. Analysis of Transformer-Isolated Diode Rectifier Circuits in Three-Phase Rectangular-Waveform Distribution System

    Science.gov (United States)

    Kito, Minoru; Watanabe, Jumpei; Takeshita, Takaharu; Nishida, Yasuyuki

    This paper presents an analysis of the steady and transient characteristics of capacitor-input-type diode rectifier circuits connected to a delta-star transformer in a three-phase rectangular-waveform distribution system. Equations are derived for the input current, output voltage, and total input power factor of the rectifier circuits. The total input power factor can be improved from 0.91 to 0.98 by using the delta-star transformer. Further, design methods are developed for both the input reactor and output capacitor of the rectifier circuits. A small input reactor is desirable for obtaining a large total input power factor and a constant output voltage. The output capacitor can be designed to obtain the required output voltage variation in steady and transient states. The effectiveness of the proposed analysis is experimentally verified by using a 2.4kW prototype.

  18. COST-BENEFIT ANALYSIS OF BIOCONVERSION NEUFCHATEL WHEY INTO RECTIFIED ETHANOL AND ORGANIC LIQUID FERTILIZER IN SEMI PILOT SCALE

    Directory of Open Access Journals (Sweden)

    Gemilang Lara UTAMA

    2015-10-01

    Full Text Available Aims of the study was to determine the cost-benefit analysis in neufchatel whey bioconversion into rectified ethanol and organic liquid fertilizer. Bioconversion whey into rectified ethanol and organic liquid fertilizer has shown great potential as a way to reduce the pollution resulting from cheese-making process. Semi pilot scale experiment was done to ferment 5 L neufchatel whey using 5% K. lactis at 33°C for 24 h in semi anaerobic plastic container without agitation and then distilled into 96.2% purity. Data collected and analyzed descriptively related to benefit cost ratio/BCR, net present value/NPV and internal rate returns/IRR. The result showed that semi pilot scale bioconversion of neufchatel whey resulting in 106.42 ml rectified ethanol and 4404.22 ml distillery residue. Economic benefit could achieved by the support of distillery residue sales as organic liquid fertilizer.

  19. Genetic Algorithm-Based Design of the Active Damping for an LCL-Filter Three-Phase Active Rectifier

    DEFF Research Database (Denmark)

    Liserre, Marco; Aquila, Antonio Dell; Blaabjerg, Frede

    2004-01-01

    of this filter is easily done, for a wide range of sampling frequencies, with the use of genetic algorithms. This method is used only for the optimum choice of the parameters in the filter, and an on-line implementation is not needed. Thus the resulting active damping solution does not need new sensors......Active rectifiers/inverters are becoming used more and more often in regenerative systems and distributed power systems. Typically, the interface between the grid and rectifier is either an inductor or an LCL-filter. The use of an LCL-filter mitigates the switching ripple injected in the grid...... by a three-phase active rectifier. However, stability problems can arise in the current control loop. In order to overcome them, a damping resistor can be inserted, at the price of a reduction of efficiency. The use of active damping by means of control may seem attractive, but it is often limited by the use...

  20. American Dream Delayed

    DEFF Research Database (Denmark)

    Khorunzhina, Natalia; Miller, Robert A.

    This paper investigates the delay in homeownership and a subsequent reduction in homeownership rate observed over the past decades. We focus on the delay in giving birth to children and increased labor market participation as contributing factors to homeownership dynamics for prime-age female hou...

  1. Delayed crosslinking HPAM gel system based on competitive inclusion

    Science.gov (United States)

    Xu, Bin

    2017-01-01

    Delayed crosslinking polymer gel system is widely used in profile control for water production control in high permeability reservoir and fracture reservoir in oilfields for many years. In this paper, a kind of delayed crosslinking HPAM gel system was prepared based on competitive inclusion and its delayed crosslinking property was studied. Phenol can be rapidly released from the cavity of β-CD ring in the presence of alcohols. The stronger the hydrophobicity of the competitive agents, the higher release rate of phenol from inclusion complex. The delayed gelation time of the delayed crosslinking HPAM gel system is closely related to the hydrophobicity difference between the competitive agents and the crosslinker. The delayed gelation time of delayed crosslinking HPAM gel system the decreased with the increasing hydrophobicity difference between the competitive agents and the crosslinker.

  2. Delay Choice vs. Delay Maintenance: Different Measures of Delayed Gratification in Capuchin Monkeys (Cebus apella)

    OpenAIRE

    Addessi, Elsa; Paglieri, Fabio; Beran, Michael J.; Evans, Theodore A.; Macchitella, Luigi; De Petrillo, Francesca; Focaroli, Valentina

    2013-01-01

    Delaying gratification involves two components: (i) delay choice (selecting a delayed reward over an immediate one), and (ii) delay maintenance (sustaining the decision to delay gratification even if the immediate reward is available during the delay). In primates, two tasks most commonly have explored these components, the Intertemporal choice task and the Accumulation task. It is unclear whether these tasks provide equivalent measures of delay of gratification. Here, we compared the perform...

  3. Structure-dependent behaviors of diode-triggered silicon controlled rectifier under electrostatic discharge stress

    Science.gov (United States)

    Zhang, Li-Zhong; Wang, Yuan; He, Yan-Dong

    2016-12-01

    The comprehensive understanding of the structure-dependent electrostatic discharge behaviors in a conventional diode-triggered silicon controlled rectifier (DTSCR) is presented in this paper. Combined with the device simulation, a mathematical model is built to get a more in-depth insight into this phenomenon. The theoretical studies are verified by the transmission-line-pulsing (TLP) test results of the modified DTSCR structure, which is realized in a 65-nm complementary metal-oxide-semiconductor (CMOS) process. The detailed analysis of the physical mechanism is used to provide predictions as the DTSCR-based protection scheme is required. In addition, a method is also presented to achieve the tradeoff between the leakage and trigger voltage in DTSCR. Project supported by the Beijing Municipal Natural Science Foundation, China (Grant No. 4162030) and the National Science and Technology Major Project of China (Grant No. 2013ZX02303002).

  4. Performance Analysis of Rectifier in NH3-H2O Absorption Heat Pump

    Science.gov (United States)

    Tsujimori, Atushi; Ozaki, Eiichi; Nakao, Kazushige

    Characteristic of stripping section of packed-tower type rectifierwas presentedin previous paper. In order to improve NH3 concentration inrefrigerant vapor, enriching section is considered effective. Refrigerant vapor from stripping section of rectifier and reflux solution from partial condenser flow into this section, and the proportion of solution flow rate to vapor flow rate of enriching section called reflux ratio is much smaller than that of stripping section. So the effect of reflux ratio on rectification process might be larger. In this paper the effect of reflux flow rate and NH3 concentration in reflux solution is investigated experimentally. As a result, it was derived that the performance of enriching section was mainly decided by reflux ratio. Then the effect of rectification performance on heat rate of partial condenser and evaporator was evaluated using the experimental result of enriching section performance.

  5. A vector modulated three-phase four-quadrant rectifier - Application to a dc motor drive

    Energy Technology Data Exchange (ETDEWEB)

    Jussila, Matti; Salo, Mika; Kaehkoenen, Lauri; Tuusa, Heikki

    2004-07-01

    This paper introduces a theory for a space vector modulation of a three-phase four-quadrant PWM rectifier (FQR). The presented vector modulation method is simple to realize with a microcontroller and it replaces the conventional modulation methods based on the analog technology. The FQR may be used to supply directly a dc load, e.g. a dc machine. The vector modulated FQR is tested in simulations supplying a 4.5 kW dc motor. The simulations show the benefits of the vector modulated FQR against thyristor converters: the supply currents are sinusoidal and the displacement power factor of the supply can be controlled. Furthermore the load current is smooth. (author)

  6. 28.3THz bowtie antenna integrated rectifier for infrared energy harvesting

    KAUST Repository

    Gadalla, Mena N.

    2014-10-01

    The design, fabrication and characterization of an asymmetric 28.3 THz antenna integrated rectifier (rectenna) using Au/Al2O3/Pt is presented. The rectenna design comprises a sharp tip bowtie antenna and a tunneling Metal-insulator-Metal (MIM) diode. The design benefits from the geometric field enhancement around the nano tips of the bowtie antenna. Simultaneous optimization of the antenna\\'s length and flare angle resulted in a relative intensity enhancement of 104 for a 10 nm gap. In order to benefit from the field enhancement, the THz diode is realized through the overlap of the bowtie sharp tips exactly at the hot spot. Dissimilar electrodes are used to allow THz signals rectification at zero bias, which is critical for energy harvesting applications. The rectenna exhibits a zero bias responsivity of 10 A/W. © 2014 European Microwave Association.

  7. Rectified-Linear-Unit-Based Deep Learning for Biomedical Multi-label Data.

    Science.gov (United States)

    Wang, Pu; Ge, Ruiquan; Xiao, Xuan; Cai, Yunpeng; Wang, Guoqing; Zhou, Fengfeng

    2017-09-01

    Disease diagnosis is one of the major data mining questions by the clinicians. The current diagnosis models usually have a strong assumption that one patient has only one disease, i.e. a single-label data mining problem. But the patients, especially when at the late stages, may have more than one disease and require a multi-label diagnosis. The multi-label data mining is much more difficult than a single-label one, and very few algorithms have been developed for this situation. Deep learning is a data mining algorithm with highly dense inner structure and has achieved many successful applications in the other areas. We propose a hypothesis that rectified-linear-unit-based deep learning algorithm may also be good at the clinical questions, by revising the last layer as a multi-label output. The proof-of-concept experimental data support the hypothesis, and the community may be interested in trying more applications.

  8. Negative differential resistance and rectifying performance induced by doped graphene nanoribbons p-n device

    Science.gov (United States)

    Zhou, Yuhong; Qiu, Nianxiang; Li, Runwei; Guo, Zhansheng; Zhang, Jian; Fang, Junfeng; Huang, Aisheng; He, Jian; Zha, Xianhu; Luo, Kan; Yin, Jingshuo; Li, Qiuwu; Bai, Xiaojing; Huang, Qing; Du, Shiyu

    2016-03-01

    Employing nonequilibrium Green's Functions in combination with density functional theory, the electronic transport properties of armchair graphene nanoribbon (GNR) devices with various widths are investigated in this work. In the adopted model, two semi-infinite graphene electrodes are periodically doped with boron or nitrogen atoms. Our calculations reveal that these devices have a striking nonlinear feature and show notable negative differential resistance (NDR). The results also indicate the diode-like properties are reserved and the rectification ratios are high. It is found the electronic transport properties are strongly dependent on the width of doped nanoribbons and the positions of dopants and three distinct families are elucidated for the current armchair GNR devices. The NDR as well as rectifying properties can be well explained by the variation of transmission spectra and the relative shift of discrete energy states with applied bias voltage. These findings suggest that the doped armchair GNR is a promising candidate for the next generation nanoscale device.

  9. Understanding of self-terminating pulse generation using silicon controlled rectifier and RC load

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chris, E-mail: chrischang81@gmail.com; Karunasiri, Gamani, E-mail: karunasiri@nps.edu [Department of Physics, Naval Postgraduate School, Monterey, CA 93943 (United States); Alves, Fabio, E-mail: falves@alionscience.com [Alion Science and Technology at NPS, Monterey, CA 93943 (United States)

    2016-01-15

    Recently a silicon controlled rectifier (SCR)-based circuit that generates self-terminating voltage pulses was employed for the detection of light and ionizing radiation in pulse mode. The circuit consisted of a SCR connected in series with a RC load and DC bias. In this paper, we report the investigation of the physics underlying the pulsing mechanism of the SCR-based. It was found that during the switching of SCR, the voltage across the capacitor increased beyond that of the DC bias, thus generating a reverse current in the circuit, which helped to turn the SCR off. The pulsing was found to be sustainable only for a specific range of RC values depending on the SCR’s intrinsic turn-on/off times. The findings of this work will help to design optimum SCR based circuits for pulse mode detection of light and ionizing radiation without external amplification circuitry.

  10. Characterization of the chicken inward rectifier K+ channel IRK1/Kir2.1 gene

    Directory of Open Access Journals (Sweden)

    Locke Emily

    2004-11-01

    Full Text Available Abstract Background Inward rectifier potassium channels (IRK contribute to the normal function of skeletal and cardiac muscle cells. The chick inward rectifier K+ channel cIRK1/Kir2.1 is expressed in skeletal muscle, heart, brain, but not in liver; a distribution similar but not identical to that of mouse Kir2.1. We set out to explore regulatory domains of the cIRK1 promoter that enhance or inhibit expression of the gene in different cell types. Results We cloned and characterized the 5'-flanking region of cIRK1. cIRK1 contains two exons with splice sites in the 5'-untranslated region, a structure similar to mouse and human orthologs. cIRK1 has multiple transcription initiation sites, a feature also seen in mouse. However, while the chicken and mouse promoter regions share many regulatory motifs, cIRK1 possesses a GC-richer promoter and a putative TATA box, which appears to positively regulate gene expression. We report here the identification of several candidate cell/tissue specific cIRK1 regulatory domains by comparing promoter activities in expressing (Qm7 and non-expressing (DF1 cells using in vitro transcription assays. Conclusion While multiple transcription initiation sites and the combinatorial function of several domains in activating cIRK1 expression are similar to those seen in mKir2.1, the cIRK1 promoter differs by the presence of a putative TATA box. In addition, several domains that regulate the gene's expression differentially in muscle (Qm7 and fibroblast cells (DF1 were identified. These results provide fundamental data to analyze cIRK1 transcriptional mechanisms. The control elements identified here may provide clues to the tissue-specific expression of this K+ channel.

  11. Origin of delayed outward ionic current in charge movement traces from frog skeletal muscle.

    Science.gov (United States)

    Hui, C S; Chen, W

    1994-08-15

    1. Non-linear membrane ionic current was studied in highly stretched cut frog twitch fibres in a double Vaseline-gap voltage clamp chamber, with the internal solution containing 0.1 mM EGTA and the external solution containing Cl- as the major anion. After the Na+ currents was abolished by TTX in the external solution and the K+ currents were suppressed by external TEA+ and Rb+ and internal Cs+, a delayed outward ionic current with a time course similar to that of the delayed rectifier current was observed during depolarization. 2. The delayed outward ionic current was resistant to 1 mM 3,4-diaminopyridine (3,4-DAP) in the external solution and was unaltered when a fraction of the internal Cs+ was replaced by K+ or Na+, suggesting that the current was not carried by cations flowing through the delayed rectifiers. 3. The delayed outward ionic current was greatly reduced by replacing the external Cl- with CH3SO3-,SO4(2-), glutamate or gluconate, indicating strongly that the current was carried by Cl- flowing through anion channels. The current was also suppressed by 1 mM external 9-anthracenecarboxylic acid (9-ACA). 4. The delayed outward ionic current was reduced by blockers of calcium-dependent Cl- channels, such as SITS and frusemide (furosemide), in a dose- and voltage-dependent manner and by increasing intracellular [EGTA] to 20 mM, suggesting that part of the Cl- current in the muscle fibres could be calcium dependent. 5. The total Cl- current could be dissected into calcium-dependent and calcium-independent components. Each component accounted for roughly half of the total Cl- current. The maximum slope conductance of the calcium-dependent Cl- channels was 60.9 +/- 6.0 microS microF-1 (mean +/- S.E.M., n = 4).

  12. Delayed Puberty (For Teens)

    Science.gov (United States)

    ... developed later than usual, too. This is called constitutional delay (or being a late bloomer), and it ... eventually — and even when you believe they're right — it's difficult to wait for something that can ...

  13. Delayed Sequence Intubation

    DEFF Research Database (Denmark)

    Weingart, Scott D; Trueger, N Seth; Wong, Nelson

    2015-01-01

    , patients were paralyzed and intubated. The primary outcome of this study was the difference in oxygen saturations after maximal attempts at preoxygenation before delayed sequence intubation compared with saturations just before intubation. Predetermined secondary outcomes and complications were also...... assessed. RESULTS: A total of 62 patients were enrolled: 19 patients required delayed sequence intubation to allow nonrebreather mask, 39 patients required it to allow NIPPV, and 4 patients required it for nasogastric tube placement. Saturations increased from a mean of 89.9% before delayed sequence...... intubation to 98.8% afterward, with an increase of 8.9% (95% confidence interval 6.4% to 10.9%). Thirty-two patients were in a predetermined group with high potential for critical desaturation (pre-delayed sequence intubation saturations ≤93%). All of these patients increased their saturations post...

  14. Delayed puberty in boys

    Science.gov (United States)

    ... Allan CA, McLachlan RI. Androgen deficiency disorders. In: Jameson JL, De Groot LJ, de Kretser DM, et ... 350. Haddad NG, Eugster EA. Delayed puberty. In: Jameson JL, De Groot LJ, de Kretser DM, et ...

  15. A high speed PE-ALD ZnO Schottky diode rectifier with low interface-state density

    Science.gov (United States)

    Jin, Jidong; Zhang, Jiawei; Shaw, Andrew; Kudina, Valeriya N.; Mitrovic, Ivona Z.; Wrench, Jacqueline S.; Chalker, Paul R.; Balocco, Claudio; Song, Aimin; Hall, Steve

    2018-02-01

    Zinc oxide (ZnO) has recently attracted attention for its potential application to high speed electronics. In this work, a high speed Schottky diode rectifier was fabricated based on a ZnO thin film deposited by plasma-enhanced atomic layer deposition and a PtOx Schottky contact deposited by reactive radio-frequency sputtering. The rectifier shows an ideality factor of 1.31, an effective barrier height of 0.79 eV, a rectification ratio of 1.17  ×  107, and cut-off frequency as high as 550 MHz. Low frequency noise measurements reveal that the rectifier has a low interface-state density of 5.13  ×  1012 cm‑2 eV‑1, and the noise is dominated by the mechanism of a random walk of electrons at the PtO x /ZnO interface. The work shows that the rectifier can be used for both noise sensitive and high frequency electronics applications.

  16. A Modular Active Front-End Rectifier with Electronic Phase-Shifting for Harmonic Mitigation in Motor Drive Applications

    DEFF Research Database (Denmark)

    Zare, Firuz; Davari, Pooya; Blaabjerg, Frede

    2017-01-01

    In this paper, an electronic phase-shifting strategy has been optimized for a multi-parallel configuration of line-commutated rectifiers with a common dc-bus voltage used in motor drive application. This feature makes the performance of the system independent of the load profile and maximizes its...

  17. The role of rectified currents in far-field RF sheaths and in SOL losses of HHFW power on NSTX

    Directory of Open Access Journals (Sweden)

    R.J. Perkins

    2017-08-01

    Full Text Available Radio-frequency (RF rectification is an important sheath phenomenon for wave heating of plasma in fusion devices and is proposed to be the mechanism responsible for converting high-harmonic fast-wave (HHFW power in the National Spherical Torus eXperiment (NSTX into a heat flux to the divertor. RF rectification has two aspects: current rectification and voltage rectification, and, while the latter is emphasized in many application, we demonstrate the importance of current rectification in analysis of the NSTX divertor during HHFW heating. When rectified currents are accounted for in first-principle models for the heat flux to the tiles, we predict a sizeable enhancement for the heat flux in the presence of an RF field: for one case studied, the predicted heat flux increases from 0.103 MW/m2 to 0.209 MW/m2. We also demonstrate how this rectification scales with injected HHFW power by tracking probe characteristics during a HHFW power ramp; the rectified current may be clamped at a certain level. This work is important for minimizing SOL losses of HHFW power in NSTX-U but may also have implications for near-field studies of ICRF antennae: ignoring rectified current may lead to underestimated heat fluxes and overestimated rectified voltages.

  18. Role of inward rectifier potassium channels in salivary gland function and sugar feeding of the fruit fly, Drosophila melanogaster

    Science.gov (United States)

    The arthropod salivary gland is of critical importance for horizontal transmission of pathogens, yet a detailed understanding of the ion conductance pathways responsible for saliva production and excretion is lacking. A superfamily of potassium ion channels, known as inward rectifying potassium (Ki...

  19. Perceived Harm of Online Drug-Encouraging Messages: Third-Person Effect and Adolescents' Support for Rectifying Measures

    Science.gov (United States)

    Leung, Wan Chi; Lo, Ven-Hwei

    2015-01-01

    This study examines third-person perceptions (TPP) of two types of online messages--antisocial messages that encourage drug abuse and prosocial messages in the youth anti-drug campaign--and their relationship with support for three types of rectifying measures: restrictive, corrective, and promotional. A survey of 778 secondary school students…

  20. Stripe delay filters

    OpenAIRE

    Zakharov, Alexander V.; Ilchenko, Mykhailo Ye.; Trubarov, Igor V.; Pinchuk, Ludmila S.

    2016-01-01

    There are considered constructions of microsized stripe delay filters, which are realized on a basis of ceramic materials with high dielectric permittivity. Delay time of non-minimal phase filters is 7–12 ns at frequencies of 1900 MHz with relative bandwidth of 3.6–3.85%. Filters dimensions are comparable with ones used in portable communication devices. Dimensions of researched three-resonator filter at frequency of 1900 MHz are 8.4×5×2 mm with material dielectric permittivity εr = 92, and 5...

  1. Eliminating common PACU delays.

    Science.gov (United States)

    Jenkins, Jamie

    2007-01-01

    This article discusses how one hospital identified patient flow delays in its PACU By using lean methods focused on eliminating waste, the team was able to improve patient flow. Lean thinking required the team to keep issues that were important to patients at top of mind. The improvements not only saved staff time, but they also helped the department prepare for the addition of six beds by focusing on methods to eliminate delays. The team, assigned by the vice president of surgical services, included a process engineer two decision support analysts, the PACU charge nurse, the nursing manager and ad hoc department nurses. The team recommended and implemented changes to improve operational effectiveness.

  2. Artificial neural networks for control of a grid-connected rectifier/inverter under disturbance, dynamic and power converter switching conditions.

    Science.gov (United States)

    Li, Shuhui; Fairbank, Michael; Johnson, Cameron; Wunsch, Donald C; Alonso, Eduardo; Proaño, Julio L

    2014-04-01

    Three-phase grid-connected converters are widely used in renewable and electric power system applications. Traditionally, grid-connected converters are controlled with standard decoupled d-q vector control mechanisms. However, recent studies indicate that such mechanisms show limitations in their applicability to dynamic systems. This paper investigates how to mitigate such restrictions using a neural network to control a grid-connected rectifier/inverter. The neural network implements a dynamic programming algorithm and is trained by using back-propagation through time. To enhance performance and stability under disturbance, additional strategies are adopted, including the use of integrals of error signals to the network inputs and the introduction of grid disturbance voltage to the outputs of a well-trained network. The performance of the neural-network controller is studied under typical vector control conditions and compared against conventional vector control methods, which demonstrates that the neural vector control strategy proposed in this paper is effective. Even in dynamic and power converter switching environments, the neural vector controller shows strong ability to trace rapidly changing reference commands, tolerate system disturbances, and satisfy control requirements for a faulted power system.

  3. Floating-Gate Manipulated Graphene-Black Phosphorus Heterojunction for Nonvolatile Ambipolar Schottky Junction Memories, Memory Inverter Circuits, and Logic Rectifiers.

    Science.gov (United States)

    Li, Dong; Chen, Mingyuan; Zong, Qijun; Zhang, Zengxing

    2017-10-11

    The Schottky junction is an important unit in electronics and optoelectronics. However, its properties greatly degrade with device miniaturization. The fast development of circuits has fueled a rapid growth in the study of two-dimensional (2D) crystals, which may lead to breakthroughs in the semiconductor industry. Here we report a floating-gate manipulated nonvolatile ambipolar Schottky junction memory from stacked all-2D layers of graphene-BP/h-BN/graphene (BP, black phosphorus; h-BN, hexagonal boron nitride) in a designed floating-gate field-effect Schottky barrier transistor configuration. By manipulating the voltage pulse applied to the control gate, the device exhibits ambipolar characteristics and can be tuned to act as graphene-p-BP or graphene-n-BP junctions with reverse rectification behavior. Moreover, the junction exhibits good storability properties of more than 10 years and is also programmable. On the basis of these characteristics, we further demonstrate the application of the device to dual-mode nonvolatile Schottky junction memories, memory inverter circuits, and logic rectifiers.

  4. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

    2012-01-01

    We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... reconstruction approaches other than implants should be seriously considered among women who have received radiation therapy....

  5. Permissible Delay in Payments

    Directory of Open Access Journals (Sweden)

    Yung-Fu Huang

    2007-01-01

    Full Text Available The main purpose of this paper wants to investigate the optimal retailer's lot-sizing policy with two warehouses under partially permissible delay in payments within the economic order quantity (EOQ framework. In this paper, we want to extend that fully permissible delay in payments to the supplier would offer the retailer partially permissible delay in payments. That is, the retailer must make a partial payment to the supplier when the order is received. Then the retailer must pay off the remaining balance at the end of the permissible delay period. In addition, we want to add the assumption that the retailer's storage space is limited. That is, the retailer will rent the warehouse to store these exceeding items when the order quantity is larger than retailer's storage space. Under these conditions, we model the retailer's inventory system as a cost minimization problem to determine the retailer's optimal cycle time and optimal order quantity. Three theorems are developed to efficiently determine the optimal replenishment policy for the retailer. Finally, numerical examples are given to illustrate these theorems and obtained a lot of managerial insights.

  6. Delayed visual maturation.

    OpenAIRE

    Harel, S; Holtzman, M; Feinsod, M

    1983-01-01

    Three infants, recognised as blind during the first 4 months of life, were found to be normal on neurological and ophthalmological examinations. Visual electro-diagnostic studies showed normal retinal responses, but delayed conduction velocities and impaired visually-evoked responses over the occipital cortex. After age 6 months, normal vision developed gradually and all abnormalities disappeared.

  7. Delayed visual maturation.

    Science.gov (United States)

    Harel, S; Holtzman, M; Feinsod, M

    1983-01-01

    Three infants, recognised as blind during the first 4 months of life, were found to be normal on neurological and ophthalmological examinations. Visual electro-diagnostic studies showed normal retinal responses, but delayed conduction velocities and impaired visually-evoked responses over the occipital cortex. After age 6 months, normal vision developed gradually and all abnormalities disappeared. PMID:6189454

  8. First principles design of divacancy defected graphene nanoribbon based rectifying and negative differential resistance device

    Directory of Open Access Journals (Sweden)

    Soubhik Chakrabarty

    2015-08-01

    Full Text Available We have studied using density functional theory and non-equilibrium Green’s function based approach, the electronic structures of 555-777 divacancy (DV defected armchair edged graphene nanoribbons (AGNR as well as the transport properties of AGNR based two-terminal devices constructed with one defected electrode and one N doped electrode. Introduction of 555-777 DV defect into AGNR results in shifting of the π and π∗ bands towards the higher energy value indicating a downward shift of the Fermi level. Formation of a potential barrier, analogous to that of conventional p-n junction, has been observed across the junction of defected and N-doped AGNR. The two terminal devices show diode like property with high rectifying efficiency for a wide range of bias voltages. The devices also show robust negative differential resistance with very high peak-to-valley ratio. Shift of the electrode energy states and modification of the transmission function with applied bias have been analyzed, in order to gain an insight into the nonlinear and asymmetric behavior of the current-voltage characteristics. Variation of the transport properties on the width of the ribbons has also been discussed.

  9. Protocol converter for serial communication between digital rectifier controllers and a power plant SCADA system

    Directory of Open Access Journals (Sweden)

    Vukić Vladimir Đ.

    2016-01-01

    Full Text Available The paper describes the protocol converter INT-485-MBRTU, developed for serial communication between the thyristor rectifier (based on the proprietary protocol "INT-CPD-05", according to standard RS-485 and the SCADA system (based on protocol "Modbus RTU", of the same standard in the thermal power plant "Nikola Tesla B1". Elementary data on industrial communication protocols and communication gateways were provided. The basic technical characteristics of the "Omron" programmable logic controller CJ series were described, as well as the developed device INT-485-MBRTU. Protocol converters with two versions of communication software were tested, differing only in one control word, intended for a forced successive change of communication sequences, in opposite to automatic sequence relieve. The device iNT-485-MBRTU, with the program for forced successive change of communication sequences, demonstrated the reliability of data transfer of 100 %, in a sample of approximately 480 messages. For nearly the same sample, the same protocol converter, with a version of the program without any type of message identifiers, transferred less than 60 % of the foreseen data. During multiple sixty-hour tests, the reliability of data transfer of at least 99.9979% was recorded, in 100% of the analysed cases, and for a sample of nearly 96,000 pairs of the send and receive messages. We analysed the results and estimated the additional possibilities for application of the INT-485-MBRTU protocol converter.

  10. Inwardly rectifying potassium channels influence Drosophila wing morphogenesis by regulating Dpp release.

    Science.gov (United States)

    Dahal, Giri Raj; Pradhan, Sarala Joshi; Bates, Emily Anne

    2017-08-01

    Loss of embryonic ion channel function leads to morphological defects, but the underlying reason for these defects remains elusive. Here, we show that inwardly rectifying potassium (Irk) channels regulate release of the Drosophila bone morphogenetic protein Dpp in the developing fly wing and that this is necessary for developmental signaling. Inhibition of Irk channels decreases the incidence of distinct Dpp-GFP release events above baseline fluorescence while leading to a broader distribution of Dpp-GFP. Work by others in different cell types has shown that Irk channels regulate peptide release by modulating membrane potential and calcium levels. We found calcium transients in the developing wing, and inhibition of Irk channels reduces the duration and amplitude of calcium transients. Depolarization with high extracellular potassium evokes Dpp release. Taken together, our data implicate Irk channels as a requirement for regulated release of Dpp, highlighting the importance of the temporal pattern of Dpp presentation for morphogenesis of the wing. © 2017. Published by The Company of Biologists Ltd.

  11. Frequency dependent rectifier memristor bridge used as a programmable synaptic membrane voltage generator

    Directory of Open Access Journals (Sweden)

    Oliver Pabst

    2013-03-01

    Full Text Available Reasoned by its dynamical behavior, the memristor enables a lot of new applications in analog circuit design. Since some realizations have been shown (e.g. 2007 by Hewlett Packard, the development of applications with memristors becomes more and more interesting. Besides applications in neural networks and storage devices, analog memristive circuits also promise further applications. Therefore, this article proposes a frequency dependent rectifier memristor bridge for different purposes, for example, using as a programmable synaptic membrane voltage generator for Spike-Time-Dependent-Plasticity and describes the circuit theory. In this context it is shown that the Picard Iteration is one possibility to analytically solve the system of nonlinear state equations of memristor circuits. An intuitive picture of how a memristor works in a network in general is given as well and in this context some research on the dynamical behavior of a HP memristor should be done. After all it is suggested to use the memristor bridge as a neuron.

  12. High voltage 4H SiC rectifiers using Pt and Ni metallization

    Energy Technology Data Exchange (ETDEWEB)

    Saxena, V.; Steckl, A.J. [Cincinnati Univ., OH (United States). Nanoelectronic Lab.

    1998-08-01

    We have fabricated high voltage 4H SiC rectifier diodes using Ni and Pt as metals for the Schottky contacts. At a current density of 100 A/cm{sup 2}, these diodes had a forward voltage drop of 1.76 and 1.86 V, respectively. Both Ni- and Pt-SiC diodes had breakdown voltages >1000 V. Pt-based SiC diodes exhibited a higher on-off current ratio (>10{sup 8}) and lower ideality factor (1.11) at room temperature than the Ni-based diodes (>10{sup 6} and 1.29). The diodes were operated at elevated temperatures up to 450 C for forward bias and 300 C for reverse bias. The room temperature barrier height of Ni on 4H SiC was determined to be 1.31 eV and the specific on-resistance of the diodes was found to be {proportional_to}8 m{Omega}-cm{sup 2}. (orig.) 9 refs.

  13. 28 nm CMOS process ESD protection based on diode-triggered silicon controlled rectifier

    Science.gov (United States)

    Li, Xiang; Dong, Shurong; Jin, Hao; Miao, Meng; Hu, Tao; Guo, Wei; Wong, Hei

    2017-11-01

    The downsizing of CMOS technology into the decananometer range has called for the redesign of the ESD protection devices because of the constraints of lower operation voltage and smaller breakdown voltage of the ultrathin gate oxide. In this work, we had developed a two-dimensional diode-triggered silicon-controlled rectifier (TD-DTSCR) structure to cope with the narrowed ESD design window in the 28 nm CMOS technology. A sufficient large SCR trigger voltage was obtained by directing the triggering current to both longitude and lateral directions, through two parasitic diodes and the P-Well, so as to save the chip area for realization. Optimization was done by varying several device parameters and the best ESD robustness obtained was 53.7 mA/μm which was about 65% larger than that of a simple SCR with the same width of 30 μm and realized using the same technology. Failure analysis was also conducted to identify the possible weak spots of the proposed structure.

  14. Length dependence of rectification in organic co-oligomer spin rectifiers

    Science.gov (United States)

    Gui-Chao, Hu; Zhao, Zhang; Ying, Li; Jun-Feng, Ren; Chuan-Kui, Wang

    2016-05-01

    The rectification ratio of organic magnetic co-oligomer diodes is investigated theoretically by changing the molecular length. The results reveal two distinct length dependences of the rectification ratio: for a short molecular diode, the charge-current rectification changes little with the increase of molecular length, while the spin-current rectification is weakened sharply by the length; for a long molecular diode, both the charge-current and spin-current rectification ratios increase quickly with the length. The two kinds of dependence switch at a specific length accompanied with an inversion of the rectifying direction. The molecular ortibals and spin-resolved transmission analysis indicate that the dominant mechanism of rectification suffers a change at this specific length, that is, from asymmetric shift of molecular eigenlevels to asymmetric spatial localization of wave functions upon the reversal of bias. This work demonstrates a feasible way to control the rectification in organic co-oligomer spin diodes by adjusting the molecular length. Project supported by the National Natural Science Foundation of China (Grant No. 11374195), the Natural Science Foundation of Shandong Province, China (Grant No. ZR2014AM017), the Taishan Scholar Project of Shandong Province, China, and the Excellent Young Scholars Research Fund of Shandong Normal University, China.

  15. Rectified brownian transport in corrugated channels: Fractional brownian motion and Lévy flights.

    Science.gov (United States)

    Ai, Bao-quan; Shao, Zhi-gang; Zhong, Wei-rong

    2012-11-07

    We study fractional brownian motion and Lévy flights in periodic corrugated channels without any external driving forces. From numerical simulations, we find that both fractional gaussian noise and Lévy-stable noise in asymmetric corrugated channels can break thermodynamical equilibrium and induce directed transport. The rectified mechanisms for fractional brownian motion and Lévy flights are different. The former is caused by non-uniform spectral distribution (low or high frequencies) of fractional gaussian noise, while the latter is due to the nonthermal character (occasional long jumps) of the Lévy-stable noise. For fractional brownian motion, average velocity increases with the Hurst exponent for the persistent case, while for the antipersistent case there exists an optimal value of Hurst exponent at which average velocity takes its maximal value. For Lévy flights, the group velocity decreases monotonically as the Lévy index increases. In addition, for both cases, the optimized periodicity and radius at the bottleneck can facilitate the directed transport. Our results could be implemented in constrained structures with narrow channels and pores where the particles undergo anomalous diffusion.

  16. Modulation of voltage-dependent inactivation of the inwardly rectifying K+ channel by chloramine-T.

    Science.gov (United States)

    Koumi, S; Sato, R; Hayakawa, H

    1994-06-13

    The inwardly rectifying K+ channel (IK1) exhibits voltage-dependent inactivation at membrane voltages more negative than approximately -140 mV. The effect of chloramine-T on the inactivation of IK1 was examined in guinea-pig ventricular myocytes using the patch-clamp technique. Chloramine-T (2 mM) irreversibly inhibited the time-dependent decay of whole-cell IK1 inactivation. As a result, the negative slope region of the current-voltage (I-V) relationship was abolished. In cell-attached single channel recordings, the number of active channels in the patch decreased with time during the voltage-clamp step to the K+ equilibrium potential (EK) of -100 mV. Chloramine-T prevented this time-dependent decrease in channel number, and ensemble averaged currents exhibited abolishment of time-dependent decay of channel activity at EK -100 mV. These results suggest that the hyperpolarization-induced inactivation of cardiac IK1 is controlled by voltage-dependent intrinsic gating.

  17. Delayed fluorescence in photosynthesis.

    Science.gov (United States)

    Goltsev, Vasilij; Zaharieva, Ivelina; Chernev, Petko; Strasser, Reto J

    2009-01-01

    Photosynthesis is a very efficient photochemical process. Nevertheless, plants emit some of the absorbed energy as light quanta. This luminescence is emitted, predominantly, by excited chlorophyll a molecules in the light-harvesting antenna, associated with Photosystem II (PS II) reaction centers. The emission that occurs before the utilization of the excitation energy in the primary photochemical reaction is called prompt fluorescence. Light emission can also be observed from repopulated excited chlorophylls as a result of recombination of the charge pairs. In this case, some time-dependent redox reactions occur before the excitation of the chlorophyll. This delays the light emission and provides the name for this phenomenon-delayed fluorescence (DF), or delayed light emission (DLE). The DF intensity is a decreasing polyphasic function of the time after illumination, which reflects the kinetics of electron transport reactions both on the (electron) donor and the (electron) acceptor sides of PS II. Two main experimental approaches are used for DF measurements: (a) recording of the DF decay in the dark after a single turnover flash or after continuous light excitation and (b) recording of the DF intensity during light adaptation of the photosynthesizing samples (induction curves), following a period of darkness. In this paper we review historical data on DF research and recent advances in the understanding of the relation between the delayed fluorescence and specific reactions in PS II. An experimental method for simultaneous recording of the induction transients of prompt and delayed chlorophyll fluorescence and decay curves of DF in the millisecond time domain is discussed.

  18. Perancangan Rectenna (Rectifier Antenna) Sebagai Pengubah Daya Elektromagnetik Menjadi Output DC Pada Frekuensi Wifi 2.4 Ghz

    OpenAIRE

    Ali Mustofa, ST., MT., Ahmad Fauzi., Rudy Yuwono, ST., M.Sc

    2014-01-01

    Penelitian ini membahas tentang perancangan dan pembuatan rectenna (rectifier antenna) sebagai pengubah daya elektromagnetik menjadi output DC yang bekerja pada frekuensi wifi 2.4 Ghz. Pemanenan energi ini merupakan salah satu alternatif konversi energi, di mana melalui proses ini dapat menghasilkan daya listrik yang dapat digunakan pada perangkat yang membutuhkan daya yang kecil. Dalam proses perancangan dan pembuatan rectenna ini dilakukan simulasi dengan menggunakan software Multisim 11 un...

  19. Organic Diode Rectifiers Based on a High-Performance Conjugated Polymer for a Near-Field Energy-Harvesting Circuit.

    Science.gov (United States)

    Higgins, Stuart G; Agostinelli, Tiziano; Markham, Steve; Whiteman, Robert; Sirringhaus, Henning

    2017-12-01

    Organic diodes manufactured on a plastic substrate capable of rectifying a high-frequency radio-frequency identification signal (13.56 MHz), with sufficient power to operate an interactive smart tag, are reported. A high-performance conjugated semiconductor (an indacenodithiophene-benzothiadiazole copolymer) is combined with a carefully optimized architecture to satisfy the electrical requirements for an organic-semiconductor-based logic chip. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. A High Swithching Frequency IGBT PWM Rectifier/Inverter System For AC Motor Drives Operating From Single Phase Supply

    OpenAIRE

    Thiyagarajah, K; Ranganathan, VT; Iyenger, Ramakrishna BS

    1990-01-01

    A pulse width modulated (PWM) rectifier/inverter system using insulated gate bipolar transistors (IGBT's), capable of switching at $20 kH_z$ is reported. The base drive circuit for the IGBT, incorporating short-circuit protection, is presented. The inverter uses an Undeland snubber together with a simple energy recovery circuit, which ensures reliable and efficient operation even for $20 kH_z$ switching. The front end for the system is a regenerative single phase full bridge IGBT inverter alo...

  1. Semiconductor data book characteristics of approx. 10,000 transistors, FETs, UJTs, diodes, rectifiers, optical semiconductors, triacs and SCRs

    CERN Document Server

    Ball, A M

    1981-01-01

    Semiconductor Data Book, 11th Edition presents tables for ratings and characteristics of transistors and multiple transistors; silicon field effect transistors; unijunction transistors; low power-, variable-, power rectifier-, silicon reference-, and light emitting diodes; photodetectors; triacs; thyristors; lead identification; and transistor comparable types. The book starts by providing an introduction and explanation of tables and manufacturers' codes and addresses. Professionals requiring such data about semiconductors will find the book useful.

  2. Rectified motion in an asymmetrically structured channel due to induced-charge electrokinetic and thermo-kinetic phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Sugioka, Hideyuki, E-mail: hsugioka@shinshu-u.ac.jp [Frontier Research Center, Canon Inc. 30-2, Shimomaruko 3-chome, Ohta-ku, Tokyo 146-8501, Japan and Department of Mechanical Systems Engineering, Shinshu University 4-17-1 Wakasato, Nagano 380-8553 (Japan)

    2016-02-15

    It would be advantageous to move fluid by the gradient of random thermal noises that are omnipresent in the natural world. To achieve this motion, we propose a rectifier that uses a thermal noise along with induced-charge electroosmosis and electrophoresis (ICEO and ICEP) around a metal post cylinder in an asymmetrically structured channel and numerically examine its rectification performance. By the boundary element method combined with the thin double layer approximation, we find that rectified motion occurs in the asymmetrically structured channel due to ICEO and ICEP. Further, by thermodynamical and equivalent circuit methods, we discuss a thermal voltage that drives a rectifier consisting of a fluidic channel of an electrolyte and an impedance as a noise source. Our calculations show that fluid can be moved in the asymmetrically structured channel by the fluctuation of electric fields due to a thermal noise only when there is a temperature difference. In addition, our simple noise argument provides a different perspective for the thermo-kinetic phenomena (around a metal post) which was predicted based on the electrolyte Seebeck effect in our previous paper [H. Sugioka, “Nonlinear thermokinetic phenomena due to the Seebeck effect,” Langmuir 30, 8621 (2014)].

  3. Quantitative assessment of fetal well-being through CTG recordings: a new parameter based on phase-rectified signal average.

    Science.gov (United States)

    Fanelli, Andrea; Magenes, Giovanni; Campanile, Marta; Signorini, Maria G

    2013-09-01

    Since the 1980s, cardiotocography (CTG) has been the most diffused technique to monitor fetal well-being during pregnancy. CTG consists of the simultaneous recording of fetal heart rate (FHR) signal and uterine contractions and its interpretation is usually performed through visual inspection by trained obstetric personnel. To reduce inter- and intraobserver variabilities and to improve the efficacy of prenatal diagnosis, new quantitative parameters, extracted from the CTG digitized signals, have been proposed as additional tools in the clinical diagnosis process. In this paper, a new parameter computed on FHR time series and based on the phase-rectified signal average curve (PRSA) is introduced. It is defined as acceleration phase-rectified slope (APRS) or deceleration phase-rectified slope (DPRS) depending on the slope sign of the PRSA curve. The new PRSA parameter was applied to FHR time series of 61 healthy and 61 intrauterine growth restricted (IUGR) fetuses during CTG nonstress tests. Performance of APRS and DPRS was compared with 1) the results provided by other parameters extracted from the PRSA curve itself but already existing in the literature, and 2) other clinical indices provided by computerized cardiotocographic systems. APRS and DPRS indices performed better than any other parameter in this study in the distinction between healthy and IUGR fetuses. Our results suggest this new index might reliably contribute to the quality of early fetal diagnosis.

  4. 2015 NOAA Ortho-rectified Below Mean High Water Color Mosaic of Ports of Houston, Texas City, and Galveston, Texas: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  5. 2014 NOAA Ortho-rectified Mean Low Low Water Near-Infrared Mosaic of Puget Sound - Whidbey Island, Washington: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  6. 2015 NOAA Ortho-rectified Below Mean High Water Color Mosaic of Ports of Gulfport, Biloxi and Pascagoula, Mississippi: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  7. 2012 NOAA Ortho-rectified Mosaic of South Carolina: Northeast Point to Murphy Island, Mean Lower Low Water Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  8. 2012 NOAA Ortho-rectified Mosaic of California: Port Hueneme to Seal Rock, Mean Lower Low Water Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  9. 2013 NOAA Ortho-rectified Mean High Water Near-Infrared Mosaic of Cape Lookout, North Carolina: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  10. 2014 NOAA Ortho-rectified Mean Low Low Water Near-Infrared Mosaic of Puget Sound - Everett to Spring Beach, Washington: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  11. Rectifying Characteristics and Semiconductor-Metal Transition Induced by Interfacial Potential in the Mn3CuN/n-Si Intermetallic Heterojunction.

    Science.gov (United States)

    Shi, Kewen; Wang, Cong; Sun, Ying; Wang, Lei; Deng, Sihao; Hu, Pengwei; Lu, Huiqing; Hao, Weichang; Wang, Tianmin; Tang, Weihua

    2017-04-12

    The Mn3CuN/n-Si heterojunction device is first designed in the antiperovskite compound, and excellent rectifying characteristics are obtained. The rectification ratio (RR) reaches as large as 38.9 at 10 V, and the open-circuit voltage Voc of 1.13 V is observed under temperature of 410 K. The rectifying behaviors can be well described by the Shockley equation, indicating the existence of a Schottky diode. Simultaneously, a particular semiconductor-metal transition (SMT) behavior at 250 K is also observed in the Mn3CuN/n-Si heterojunction. The interfacial band bending induced inversion layer, which is clarified by the interfacial schematic band diagrams, is believed to be responsible for the SMT and rectifying effects. This study can develop a new class of materials for heterojunction, rectifying devices, and SMT behaviors.

  12. 2014 NOAA Ortho-rectified Mean Low Low Water Near-Infrared Mosaic of Cape Lookout, North Carolina: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  13. 2013 NOAA Ortho-rectified Mean Low Low Water Near-Infrared Mosaic of Santa Rosa Island, Florida: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  14. 2014 NOAA Ortho-rectified Mean Low Low Water Color Mosaic of Dewees Island to Bulls Bay (ICW), South Carolina: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  15. 2014 NOAA Ortho-rectified Mean High Water Near-Infrared Mosaic of Dewees Island to Bulls Bay (ICW), South Carolina: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  16. 2014 NOAA Ortho-rectified Mean High Water Color Mosaic of Dewees Island to Bulls Bay (ICW), South Carolina: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  17. 2014 NOAA Ortho-rectified Mean High Water Color Mosaic of The Channel Islands, California: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  18. 2014 NOAA Ortho-rectified Mean High Water Near-Infrared Mosaic of The Channel Islands, California: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative. The source imagery...

  19. Status report of the three phase 25 kA, 1.5 kW thermally switched superconducting rectifier, transformer and switches

    NARCIS (Netherlands)

    ten Kate, Herman H.J.; Holtslag, A.H.M.; Knoben, J.; Steffens, H.A.; van de Klundert, L.J.M.

    1983-01-01

    A 25 kA, 1.5 kW superconducting rectifier system has been developed. This rectifier system working like an a.c.-d.c, converter with a primary current of 35 A at 0.1Hz, will energize a 25 kA coil with an average power of 5.4 MJ/hr and a proposed energy efficiency of at least 96%. Such a highly

  20. Comparative Analyses of Multi-Pulse Phase Controlled Rectifiers in Continuous Conduction Mode with a Two-Pole LC Output Filter for Surface Ship DC Applications

    Science.gov (United States)

    2013-03-01

    model of a variable parameter load, several multiple-pulse count, high power rectifiers were exercised. The Simulink® results were compared to the...model of a variable parameter load, several multiple-pulse count, high power rectifiers were exercised. The Simulink® results were compared to the...Duty Officer ( EDO ) community for selecting me for lateral transfer and believing that I was a worthwhile investment in light of having already

  1. Delayed crosslinker composition

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, R.M.

    1989-01-10

    A crosslinker composition is described that can produce delayed crosslinking of an aqueous solution of a crosslinkable organic polymer. It consists of about 1% to about 10% by weight of an organic zirconium complex and about 2% to about 37% by weight organic hydroxycarboxylic acid selected from the group consisting of lactic, mandelic and hydroxyacetic acids the pH of the composition being no greater than 4.8.

  2. Delayed visual maturation.

    OpenAIRE

    Cole, G F; Hungerford, J.; Jones, R B

    1984-01-01

    Sixteen blind babies who were considered to be showing the characteristics of delayed visual maturation were studied prospectively. The diagnosis was made on clinical grounds, and the criteria for this are discussed. All of these infants developed visual responses between 4 and 6 months of age and had normal or near normal visual acuities by 1 year of age. Long term follow up, however, has shown neurological abnormalities in some of these children.

  3. Delayed visual maturation.

    Science.gov (United States)

    Fielder, A R; Russell-Eggitt, I R; Dodd, K L; Mellor, D H

    1985-01-01

    Fifty-three infants with delayed visual maturation (DVM) are presented. These have been classified according to their ocular and systemic features into three groups: DVM as an isolated anomaly, in association with mental retardation, and ocular abnormalities accompanied by DVM. The clinical features are discussed, particularly regarding the time and speed of visual improvement in the three groups. Infants with DVM who experienced difficulties in the perinatal period have an increased risk of developing permanent neurological sequelae.

  4. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

    2011-01-01

    Studies of complications following reconstructive surgery with implants among women with breast cancer are needed. As the, to our knowledge, first prospective long-term study we evaluated the occurrence of complications following delayed breast reconstruction separately for one- and two-stage pro......Studies of complications following reconstructive surgery with implants among women with breast cancer are needed. As the, to our knowledge, first prospective long-term study we evaluated the occurrence of complications following delayed breast reconstruction separately for one- and two......-stage procedures. From the Danish Registry for Plastic Surgery of the Breast, which has prospectively registered data for women undergoing breast implantations since 1999, we identified 559 women without a history of radiation therapy undergoing 592 delayed breast reconstructions following breast cancer during...... the period 1999 to 2006; 239 one-stage procedures and 353 two-stage procedures. The postoperative course through November 2009 was evaluated by cumulative incidence adjusting for competing risks for the selected outcomes; hematoma, infection, seroma, implant rupture, severe capsular contracture (modified...

  5. Delay in atomic photoionization

    CERN Document Server

    Kheifets, A S

    2010-01-01

    We analyze the time delay between emission of photoelectrons from the outer valence $ns$ and $np$ sub-shells in noble gas atoms following absorption of an attosecond XUV pulse. By solving the time dependent Schr\\"odinger equation and carefully examining the time evolution of the photoelectron wave packet, we establish the apparent "time zero" when the photoelectron leaves the atom. Various processes such as elastic scattering of the photoelectron on the parent ion and many-electron correlation affect the quantum phase of the dipole transition matrix element, the energy dependence of which defines the emission timing. This qualitatively explains the time delay between photoemission from the $2s$ and $2p$ sub-shells of Ne as determined experimentally by attosecond streaking [{\\em Science} {\\bf 328}, 1658 (2010)]. However, with our extensive numerical modeling, we were only able to account for less than a half of the measured time delay of $21\\pm5$~as. We argue that the XUV pulse alone cannot produce such a larg...

  6. Time-Delay Interferometry

    Directory of Open Access Journals (Sweden)

    Massimo Tinto

    2014-08-01

    Full Text Available Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI. This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

  7. Structural basis of drugs that increase cardiac inward rectifier Kir2.1 currents.

    Science.gov (United States)

    Gómez, Ricardo; Caballero, Ricardo; Barana, Adriana; Amorós, Irene; De Palm, Sue-Haida; Matamoros, Marcos; Núñez, Mercedes; Pérez-Hernández, Marta; Iriepa, Isabel; Tamargo, Juan; Delpón, Eva

    2014-11-01

    We hypothesize that some drugs, besides flecainide, increase the inward rectifier current (IK1) generated by Kir2.1 homotetramers (IKir2.1) and thus, exhibit pro- and/or antiarrhythmic effects particularly at the ventricular level. To test this hypothesis, we analysed the effects of propafenone, atenolol, dronedarone, and timolol on Kir2.x channels. Currents were recorded with the patch-clamp technique using whole-cell, inside-out, and cell-attached configurations. Propafenone (0.1 nM-1 µM) did not modify either IK1 recorded in human right atrial myocytes or the current generated by homo- or heterotetramers of Kir2.2 and 2.3 channels recorded in transiently transfected Chinese hamster ovary cells. On the other hand, propafenone increased IKir2.1 (EC50 = 12.0 ± 3.0 nM) as a consequence of its interaction with Cys311, an effect which decreased inward rectification of the current. Propafenone significantly increased mean open time and opening frequency at all the voltages tested, resulting in a significant increase of the mean open probability of the channel. Timolol, which interacted with Cys311, was also able to increase IKir2.1. On the contrary, neither atenolol nor dronedarone modified IKir2.1. Molecular modelling of the Kir2.1-drugs interaction allowed identification of the pharmacophore of drugs that increase IKir2.1. Kir2.1 channels exhibit a binding site determined by Cys311 that is responsible for drug-induced IKir2.1 increase. Drug binding decreases channel affinity for polyamines and current rectification, and can be a mechanism of drug-induced pro- and antiarrhythmic effects not considered until now. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  8. Nicotine at clinically relevant concentrations affects atrial inward rectifier potassium current sensitive to acetylcholine.

    Science.gov (United States)

    Bébarová, Markéta; Matejovič, Peter; Švecová, Olga; Kula, Roman; Šimurdová, Milena; Šimurda, Jiří

    2017-05-01

    Nicotine abuse is associated with variety of diseases including arrhythmias, most often atrial fibrillation (AF). Altered inward rectifier potassium currents including acetylcholine-sensitive current I K(Ach) are known to be related to AF pathogenesis. Since relevant data are missing, we aimed to investigate I K(Ach) changes at clinically relevant concentrations of nicotine. Experiments were performed by the whole cell patch clamp technique at 23 ± 1 °C on isolated rat atrial myocytes. Nicotine was applied at following concentrations: 4, 40 and 400 nM; ethanol at 20 mM (∼0.09%). Nicotine at 40 and 400 nM significantly activated constitutively active component of I K(Ach) with the maximum effect at 40 nM (an increase by ∼100%); similar effect was observed at -110 and -50 mV. Changes at 4 nM nicotine were negligible on average. Coapplication of 40 nM nicotine and 20 mM ethanol (which is also known to activate this current) did not show cumulative effect. In the case of acetylcholine-induced component of I K(Ach), a dual effect of nicotine and its correlation with the current magnitude in control were apparent: the current was increased by nicotine in the cells showing small current in control and vice versa. The effect of 40 and 400 nM nicotine on acetylcholine-induced component of I K(Ach) was significantly different at -110 and -50 mV. We conclude that nicotine at clinically relevant concentrations significantly increased constitutively active component of I K(Ach) and showed a dual effect on its acetylcholine-induced component, similarly as ethanol. Synchronous application of nicotine and ethanol did not cause additive effect.

  9. Inhibition of G protein-activated inwardly rectifying K+ channels by different classes of antidepressants.

    Directory of Open Access Journals (Sweden)

    Toru Kobayashi

    Full Text Available Various antidepressants are commonly used for the treatment of depression and several other neuropsychiatric disorders. In addition to their primary effects on serotonergic or noradrenergic neurotransmitter systems, antidepressants have been shown to interact with several receptors and ion channels. However, the molecular mechanisms that underlie the effects of antidepressants have not yet been sufficiently clarified. G protein-activated inwardly rectifying K(+ (GIRK, Kir3 channels play an important role in regulating neuronal excitability and heart rate, and GIRK channel modulation has been suggested to have therapeutic potential for several neuropsychiatric disorders and cardiac arrhythmias. In the present study, we investigated the effects of various classes of antidepressants on GIRK channels using the Xenopus oocyte expression assay. In oocytes injected with mRNA for GIRK1/GIRK2 or GIRK1/GIRK4 subunits, extracellular application of sertraline, duloxetine, and amoxapine effectively reduced GIRK currents, whereas nefazodone, venlafaxine, mianserin, and mirtazapine weakly inhibited GIRK currents even at toxic levels. The inhibitory effects were concentration-dependent, with various degrees of potency and effectiveness. Furthermore, the effects of sertraline were voltage-independent and time-independent during each voltage pulse, whereas the effects of duloxetine were voltage-dependent with weaker inhibition with negative membrane potentials and time-dependent with a gradual decrease in each voltage pulse. However, Kir2.1 channels were insensitive to all of the drugs. Moreover, the GIRK currents induced by ethanol were inhibited by sertraline but not by intracellularly applied sertraline. The present results suggest that GIRK channel inhibition may reveal a novel characteristic of the commonly used antidepressants, particularly sertraline, and contributes to some of the therapeutic effects and adverse effects.

  10. Current Vaccine Shortages and Delays

    Science.gov (United States)

    ... value="Submit" /> Related Links Vaccines & Immunizations Current Vaccine Shortages & Delays Recommend on Facebook Tweet Share Compartir ... vaccination are included in this update. Chart of Vaccines* in Delay or Shortage National Vaccine Supply Shortages ...

  11. The effects of deoxyelephantopin on the cardiac delayed rectifier potassium channel current (IKr) and human ether-a-go-go-related gene (hERG) expression.

    Science.gov (United States)

    Teah, Yi Fan; Abduraman, Muhammad Asyraf; Amanah, Azimah; Adenan, Mohd Ilham; Sulaiman, Shaida Fariza; Tan, Mei Lan

    2017-09-01

    Elephantopus scaber Linn and its major bioactive component, deoxyelephantopin are known for their medicinal properties and are often reported to have various cytotoxic and antitumor activities. This plant is widely used as folk medicine for a plethora of indications although its safety profile remains unknown. Human ether-a-go-go-related gene (hERG) encodes the cardiac IKr current which is a determinant of the duration of ventricular action potentials and QT interval. The hERG potassium channel is an important antitarget in cardiotoxicity evaluation. This study investigated the effects of deoxyelephantopin on the current, mRNA and protein expression of hERG channel in hERG-transfected HEK293 cells. The hERG tail currents following depolarization pulses were insignificantly affected by deoxyelephantopin in the transfected cell line. Current reduction was less than 40% as compared with baseline at the highest concentration of 50 μM. The results were consistent with the molecular docking simulation and hERG surface protein expression. Interestingly, it does not affect the hERG expression at both transcriptional and translational level at most concentrations, although higher concentration at 10 μM caused protein accumulation. In conclusion, deoxyelephantopin is unlikely a clinically significant hERG channel and Ikr blocker. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Long QT 1 mutation KCNQ1A344V increases local anesthetic sensitivity of the slowly activating delayed rectifier potassium current

    DEFF Research Database (Denmark)

    Siebrands, Cornelia C; Binder, Stephan; Eckhoff, Ulrike

    2006-01-01

    BACKGROUND: Anesthesia in patients with long QT syndrome (LQTS) is a matter of concern. Congenital LQTS is most frequently caused by mutations in KCNQ1 (Kv7.1), whereas drug-induced LQTS is a consequence of HERG (human ether-a-go-go-related gene) channel inhibition. The aim of this study...... was to investigate whether the LQT1 mutation A344V in the S6 region of KCNQ1, at a position corresponding to the local anesthetic binding site in HERG, may render drug insensitive KCNQ1 channels into a toxicologically relevant target of these pharmacologic agents. This may suggest that LQTS constitutes not only...... a nonspecific but also a specific pharmacogenetic risk factor for anesthesia. METHODS: The authors examined electrophysiologic and pharmacologic properties of wild-type and mutant KCNQ1 channels. The effects of bupivacaine, ropivacaine, and mepivacaine were investigated using two-electrode voltage clamp...

  13. Delaying the international spread of pandemic influenza.

    Science.gov (United States)

    Cooper, Ben S; Pitman, Richard J; Edmunds, W John; Gay, Nigel J

    2006-06-01

    The recent emergence of hypervirulent subtypes of avian influenza has underlined the potentially devastating effects of pandemic influenza. Were such a virus to acquire the ability to spread efficiently between humans, control would almost certainly be hampered by limited vaccine supplies unless global spread could be substantially delayed. Moreover, the large increases that have occurred in international air travel might be expected to lead to more rapid global dissemination than in previous pandemics. To evaluate the potential of local control measures and travel restrictions to impede global dissemination, we developed stochastic models of the international spread of influenza based on extensions of coupled epidemic transmission models. These models have been shown to be capable of accurately forecasting local and global spread of epidemic and pandemic influenza. We show that under most scenarios restrictions on air travel are likely to be of surprisingly little value in delaying epidemics, unless almost all travel ceases very soon after epidemics are detected. Interventions to reduce local transmission of influenza are likely to be more effective at reducing the rate of global spread and less vulnerable to implementation delays than air travel restrictions. Nevertheless, under the most plausible scenarios, achievable delays are small compared with the time needed to accumulate substantial vaccine stocks.

  14. Rapid Prototyping

    Science.gov (United States)

    1999-01-01

    Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

  15. Delay Choice vs. Delay Maintenance: Different Measures of Delayed Gratification in Capuchin Monkeys (Cebus apella)

    Science.gov (United States)

    Addessi, Elsa; Paglieri, Fabio; Beran, Michael J.; Evans, Theodore A.; Macchitella, Luigi; De Petrillo, Francesca; Focaroli, Valentina

    2013-01-01

    Delaying gratification involves two components: (i) delay choice (selecting a delayed reward over an immediate one), and (ii) delay maintenance (sustaining the decision to delay gratification even if the immediate reward is available during the delay). In primates, two tasks most commonly have explored these components, the Intertemporal choice task and the Accumulation task. It is unclear whether these tasks provide equivalent measures of delay of gratification. Here, we compared the performance of the same capuchin monkeys, belonging to two study populations, between these tasks. We found only limited evidence of a significant correlation in performance. Consequently, in contrast to what is often assumed, our data provide only partial support to the hypothesis that these tasks provide equivalent measures of delay of gratification. PMID:23544770

  16. Delay choice versus delay maintenance: different measures of delayed gratification in capuchin monkeys (Cebus apella).

    Science.gov (United States)

    Addessi, Elsa; Paglieri, Fabio; Beran, Michael J; Evans, Theodore A; Macchitella, Luigi; De Petrillo, Francesca; Focaroli, Valentina

    2013-11-01

    Delaying gratification involves 2 components: (1) delay choice (selecting a delayed reward over an immediate one) and (2) delay maintenance (sustaining the decision to delay gratification even if the immediate reward is available during the delay). Two tasks most commonly have explored these components in primates: the intertemporal choice task and the accumulation task. It is unclear whether these tasks provide equivalent measures of delay of gratification. Here, we compared the performance on the intertemporal choice task and the accumulation task of capuchin monkeys (Cebus apella) belonging to 2 study populations. We found only limited evidence of a significant correlation in performance. Consequently, in contrast to what is often assumed, our data provide only partial support for the hypothesis that these tasks provide equivalent measures of delay of gratification.

  17. Delaying information search

    Directory of Open Access Journals (Sweden)

    Yaniv Shani

    2012-11-01

    Full Text Available In three studies, we examined factors that may temporarily attenuate information search. People are generally curious and dislike uncertainty, which typically encourages them to look for relevant information. Despite these strong forces that promote information search, people sometimes deliberately delay obtaining valuable information. We find they may do so when they are concerned that the information might interfere with future pleasurable activities. Interestingly, the decision to search or to postpone searching for information is influenced not only by the value and importance of the information itself but also by well-being maintenance goals related to possible detrimental effects that negative knowledge may have on unrelated future plans.

  18. Epidemiology of delayed ejaculation

    Science.gov (United States)

    Di Sante, Stefania; Mollaioli, Daniele; Gravina, Giovanni Luca; Ciocca, Giacomo; Limoncin, Erika; Carosa, Eleonora; Lenzi, Andrea

    2016-01-01

    A large body of literature on diminished ejaculatory disorders has been generated without the use of a clear diagnostic definition. Many studies have not distinguished between the orgasm and ejaculation disorders leading to doubtful results. Delayed ejaculation (DE) is one of the diminished ejaculatory disorders, which range from varying delays in ejaculatory latency to a complete inability to ejaculate. The present review is aimed at providing a comprehensive overview of the current knowledge on the definition and epidemiology of diminished ejaculatory disorders. We focus on the acquired diseases, such as benign prostatic hyperplasia (BPH) and specific drug regimens that may cause an iatrogenic form of ejaculatory disorder. In addition, the impact of aging is discussed since the prevalence of DE appears to be moderately but positively related to age. Finally, we also focus on the importance of the hormonal milieu on male ejaculation. To date, evidence on the endocrine control of ejaculation is derived from small clinical trials, but the evidence suggests that hormones modulate the ejaculatory process by altering its overall latency. PMID:27652226

  19. Epidemiology of delayed ejaculation.

    Science.gov (United States)

    Di Sante, Stefania; Mollaioli, Daniele; Gravina, Giovanni Luca; Ciocca, Giacomo; Limoncin, Erika; Carosa, Eleonora; Lenzi, Andrea; Jannini, Emmanuele A

    2016-08-01

    A large body of literature on diminished ejaculatory disorders has been generated without the use of a clear diagnostic definition. Many studies have not distinguished between the orgasm and ejaculation disorders leading to doubtful results. Delayed ejaculation (DE) is one of the diminished ejaculatory disorders, which range from varying delays in ejaculatory latency to a complete inability to ejaculate. The present review is aimed at providing a comprehensive overview of the current knowledge on the definition and epidemiology of diminished ejaculatory disorders. We focus on the acquired diseases, such as benign prostatic hyperplasia (BPH) and specific drug regimens that may cause an iatrogenic form of ejaculatory disorder. In addition, the impact of aging is discussed since the prevalence of DE appears to be moderately but positively related to age. Finally, we also focus on the importance of the hormonal milieu on male ejaculation. To date, evidence on the endocrine control of ejaculation is derived from small clinical trials, but the evidence suggests that hormones modulate the ejaculatory process by altering its overall latency.

  20. Delayed Choice Quantum Cryptography

    Science.gov (United States)

    Jeffrey, Evan; Kwiat, Paul

    2002-05-01

    Quantum Cryptography has recently gained attention as a method of communication with security guaranteed by the laws of physics. In particular, according to quantum mechanics, any measurement of an unknown quantum state perturbs the state in an easily detectable manner. One practical difficulty in implementing quantum cryptography is that Alice must encode each bit in a random basis, and Bob must choose the correct basis to get a shared bit of the final key. This necessarily introduces at least a 50% loss of data rate, and higher in protocols that use more than two bases in order to be more sensitive to eavesdroppers. We show that Bob can solve this by storing his photon until Alice has send the basis to use, allowing him to measure in the correct basis 100% of the time, while preventing Eve from having that information in time to use it maliciously. Bob accomplishes this storage by means of an optical delay line -- a pair of mirrors arranged so that his photon makes many round trips through the cavity before emerging and entering the detector. By using mirrors with a slight astigmatism, hope to achieve hundreds of round trips and a few microseconds of delay time.

  1. Pseudotumoral delayed cerebral radionecrosis

    Energy Technology Data Exchange (ETDEWEB)

    Ciaudo-Lacroix, C.; Lapresle, J. (Centre Hospitalier de Bicetre, 94 - Le Kremlin-Bicetre (France))

    1985-01-01

    A 60 year-old woman with a scalp epithelioma underwent radiotherapy, the dose being 57 Gray. A first epileptic seizure occurred twenty months later. Neurological examination revealed signs of left hemisphere involvement. ..gamma..EG, angiography, CT scans, demonstrated a pseudotumoral avascular process. On account of the localisation, the patient being right-handed, no surgical procedure was performed. In spite of corticotherapy and anticonvulsive treatment, seizures recurred and neurological signs slowly progressed. The patient died, 22 months after the first seizure, of an associated disseminated carcinoma with cachexia. Neuropathological examination showed a massive lesion presenting all the features of delayed radionecrosis in the left hemisphere: situated mainly in the white matter; numerous vascular abnormalities; wide-spread demyelination; disappearance of oligoglial cells. The Authors recall the clinical and anatomical aspects of this condition for which the only successful treatment is surgical removal when location and size of the lesion permit. Finally, the mechanisms which have been proposed to explain this delayed cerebral radionecrosis are discussed.

  2. Expression of G-protein inwardly rectifying potassium channels (GIRKs in lung cancer cell lines

    Directory of Open Access Journals (Sweden)

    Schuller Hildegard M

    2005-08-01

    Full Text Available Abstract Background Previous data from our laboratory has indicated that there is a functional link between the β-adrenergic receptor signaling pathway and the G-protein inwardly rectifying potassium channel (GIRK1 in human breast cancer cell lines. We wanted to determine if GIRK channels were expressed in lung cancers and if a similar link exists in lung cancer. Methods GIRK1-4 expression and levels were determined by reverse transcription polymerase chain reaction (RT-PCR and real-time PCR. GIRK protein levels were determined by western blots and cell proliferation was determined by a 5-bromo-2'-deoxyuridine (BrdU assay. Results GIRK1 mRNA was expressed in three of six small cell lung cancer (SCLC cell lines, and either GIRK2, 3 or 4 mRNA expression was detected in all six SCLC cell lines. Treatment of NCI-H69 with β2-adrenergic antagonist ICI 118,551 (100 μM daily for seven days led to slight decreases of GIRK1 mRNA expression levels. Treatment of NCI-H69 with the β-adrenergic agonist isoproterenol (10 μM decreased growth rates in these cells. The GIRK inhibitor U50488H (2 μM also inhibited proliferation, and this decrease was potentiated by isoproterenol. In the SCLC cell lines that demonstrated GIRK1 mRNA expression, we also saw GIRK1 protein expression. We feel these may be important regulatory pathways since no expression of mRNA of the GIRK channels (1 & 2 was found in hamster pulmonary neuroendocrine cells, a suggested cell of origin for SCLC, nor was GIRK1 or 2 expression found in human small airway epithelial cells. GIRK (1,2,3,4 mRNA expression was also seen in A549 adenocarcinoma and NCI-H727 carcinoid cell lines. GIRK1 mRNA expression was not found in tissue samples from adenocarcinoma or squamous cancer patients, nor was it found in NCI-H322 or NCI-H441 adenocarcinoma cell lines. GIRK (1,3,4 mRNA expression was seen in three squamous cell lines, GIRK2 was only expressed in one squamous cell line. However, GIRK1 protein

  3. Barium toxicity and the role of the potassium inward rectifier current.

    Science.gov (United States)

    Bhoelan, B S; Stevering, C H; van der Boog, A T J; van der Heyden, M A G

    2014-07-01

    Barium is a stable divalent earth metal and highly toxic upon acute and chronic exposure. Barium is present in many products and involved in a number of industrial processes. Barium targets the potassium inward rectifier channels (IRCs) of the KCNJx gene family. Extracellular barium enters and strongly binds the potassium selectivity filter region resulting in blockade of the potassium conducting pore. IRCs are involved in numerous physiological processes of the human body and the most barium sensitive IRCs are highly expressed in all muscle types. Our purpose was correlate to the clinical outcome of acute barium poisoning in man to current knowledge on IRC function. The primary literature search was performed using Medline, Scopus and Google Scholar using search terms "barium AND poisoning"; "barium AND intoxication"; "barium AND case report" and retrieved publications from 1945 through 2012. Additional case reports were retrieved based on the reference lists of the primary hits. Duplicate publications, or publications presenting identical cases were omitted. A total of 39 case reports on acute barium poisoning containing 226 human subjects were identified for review. BaCO3 was the most frequent source and food the most frequent mode of poisoning. Patients suffered from gastrointestinal (vomiting, diarrhea), cardiovascular (arrhythmias, hypertension), neuromuscular (abnormal reflexes, paralysis), respiratory (respiratory arrest/failure) and metabolic (hypokalemia) symptoms. Severe hypokalemia (barium serum concentrations greater than or equal to 0.0025 mM. Review of the ECG outcomes demonstrated ventricular extrasystoles, ST changes and profound U-waves to be associated strongly with poisoning. Most common treatment modalities were gastric lavage, oral sulfates, potassium i.v. and cardiorespiratory support. 27 patients (12%) died from barium poisoning. Barium is a potent, non-specific inhibitor of the potassium IRC current and affects all types of muscle at

  4. Precision rectifier detectors for ac resistance bridge measurements with application to temperature control systems for irradiation creep experiments

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, M. G.

    1977-05-01

    The suitability of several temperature measurement schemes for an irradiation creep experiment is examined. It is found that the specimen resistance can be used to measure and control the sample temperature if compensated for resistance drift due to radiation and annealing effects. A modified Kelvin bridge is presented that allows compensation for resistance drift by periodically checking the sample resistance at a controlled ambient temperature. A new phase-insensitive method for detecting the bridge error signals is presented. The phase-insensitive detector is formed by averaging the magnitude of two bridge voltages. Although this method is substantially less sensitive to stray reactances in the bridge than conventional phase-sensitive detectors, it is sensitive to gain stability and linearity of the rectifier circuits. Accuracy limitations of rectifier circuits are examined both theoretically and experimentally in great detail. Both hand analyses and computer simulations of rectifier errors are presented. Finally, the design of a temperature control system based on sample resistance measurement is presented. The prototype is shown to control a 316 stainless steel sample to within a 0.15/sup 0/C short term (10 sec) and a 0.03/sup 0/C long term (10 min) standard deviation at temperatures between 150 and 700/sup 0/C. The phase-insensitive detector typically contributes less than 10 ppM peak resistance measurement error (0.04/sup 0/C at 700/sup 0/C for 316 stainless steel or 0.005/sup 0/C at 150/sup 0/C for zirconium).

  5. Wine polyphenol resveratrol inhibits contractions of isolated rat uterus by activation of smooth muscle inwardly rectifying potassium channels

    Directory of Open Access Journals (Sweden)

    Novaković Radmila

    2016-01-01

    Full Text Available Resveratrol is a phytoalexin produced in a number of plant species including grapes. The benefit of resveratrol to health is widely reported. Resveratrol has been found to promote relaxation of non-pregnant and pregnant uterus, but its mechanism of action is unclear. The aims of our study were to investigate the involvement of inwardly rectifying potassium channels (Kir in inhibitory effects of resveratrol on three models of contractions of non-pregnant rat uterus: the spontaneous rhythmic contractions (SRC, oxytocin-elicited phasic contractions and tonic oxytocin-elicited contractions.Uterine strips were obtained from virgin female Wistar rats in oestrus. Strips were mounted into organ bath for recording isometric tension in Krebs-Ringer solution. Experiments followed a multiple curve design. In order to test the involvement of Kirchannels in a mechanism of action of resveratrol(1-100 μM,BaCl2 (1 mM,a antagonist of inwardly rectifying pota­ssium channels was used. Resveratrol induced a concentration-dependent relaxation of all models of contractions. BaCl2 antagonized the response to resveratrolon SRC and oxytocin-elicited phasic contractions. Relaxation achieved by resveratrolon tonic oxytocin-elicited concentrations was insensitive to BaCl2.The antagonism of resveratrol effects by inwardly rectifying potassium channels antagonist suggests that Kir channels are involved in resveratrol action on phasic contractions of rat uterus. Inhibitory effect of resveratrol on tonic contractions did not include Kir channels. [Projekat Ministartsva nauke Republike Srbije, br. TR31020

  6. Power supplies of dc generators. Part II. Power rectifier circuits; Stromversorgung von Gleichstrommaschinen. Teil II. Leistungs-Gleichrichterschaltungen

    Energy Technology Data Exchange (ETDEWEB)

    Kunze, G.

    2003-05-01

    Double-star power rectifier circuits reduce harmonics but produce power only during a very short half-wave time. This can be remedied by installing an additional interphase transformer, which also improves the capacity utilisation by 14 percent. This complex circuit is illustrated by the example of a two-phase system. [German] Drehstromgleichrichter in Doppelsternschaltung sorgen fuer eine deutlich geringere Oberwelligkeit der Gleichspannung, liefern aber nur waehrend einer sehr kurzen Halbwellenzeit Strom. Mit einer zusaetzlichen Saugdrossel laesst sich dieses Manko jedoch umgehen. Zudem sind Netztrafo und Drossel um ca. 14% besser ausgenutzt. Das Wirkprinzip einer solchen Schaltung ist allerdings recht kompliziert und wird deshalb an einem zweiphasigen System erklaert. (orig.)

  7. Simulations and Analysis and Operating Regime as Rectifier with Power Factor Correction of Two - Quadrant Converter with RNSIC

    Directory of Open Access Journals (Sweden)

    PLETEA, I.V.

    2009-10-01

    Full Text Available In this paper, a new topology for a two-quadrant converter is presented. In the AC/DC transfer mode, the converter works as a rectifier with near sinusoidal input currents (RNSIC, while in the DC/AC transfer mode it works as a square-wave pulse switching inverter. We offer some suggestions for the converter design and realize a comparison with a two-quadrant PWM converter. The new converter is characterized by smaller power losses, reduced EMI problems and higher reliability.

  8. Three-phase current transformer rectifier sets. High-voltage power supplies for difficult conditions in electrostatic precipitators

    Energy Technology Data Exchange (ETDEWEB)

    Stackelberg, Josef von [Rico-Werk Eiserlo und Emmrich GmbH, Toenisvorst (Germany)

    2013-04-01

    The precipitation rate of electrostatic precipitators (ESP) highly depends on the consistency of waste gas. Among other things, electrical conductivity plays an important role as well as the ability of particles to be electrically charged or ionised. Within certain limits, common ESPs are able to clean waste gas satisfactorily. If the dust attributes exceed these limits, more sophisticated technical solutions are required in the ESP to meet the demands for the gas cleaning equipment. In these cases, a three phase transformer rectifier system offers an alternative to the conventional single phase system, as it delivers a smooth direct current voltage over a wide voltage range. (orig.)

  9. Stability and delay sensitivity of neutral fractional-delay systems

    Science.gov (United States)

    Xu, Qi; Shi, Min; Wang, Zaihua

    2016-08-01

    This paper generalizes the stability test method via integral estimation for integer-order neutral time-delay systems to neutral fractional-delay systems. The key step in stability test is the calculation of the number of unstable characteristic roots that is described by a definite integral over an interval from zero to a sufficient large upper limit. Algorithms for correctly estimating the upper limits of the integral are given in two concise ways, parameter dependent or independent. A special feature of the proposed method is that it judges the stability of fractional-delay systems simply by using rough integral estimation. Meanwhile, the paper shows that for some neutral fractional-delay systems, the stability is extremely sensitive to the change of time delays. Examples are given for demonstrating the proposed method as well as the delay sensitivity.

  10. Delayed cure bismaleimide resins

    Science.gov (United States)

    Adams, Johnnie E.; Jamieson, Donald R.

    1984-08-07

    Polybismaleimides prepared by delayed curing of bis-imides having the formula ##STR1## wherein R.sub.1 and R.sub.2 each independently is H, C.sub.1-4 -alkyl, C.sub.1-4 -alkoxy, Cl or Br, or R.sub.1 and R.sub.2 together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R.sub.1 and R.sub.2 are not t-butyl or t-butoxy; X is O, S or Se; n is 1-3; and the --(CH.sub.2).sub.n -- group, optionally, is substituted by 1-3 methyl groups or by fluorine.

  11. Delay tolerant networks

    CERN Document Server

    Gao, Longxiang; Luan, Tom H

    2015-01-01

    This brief presents emerging and promising communication methods for network reliability via delay tolerant networks (DTNs). Different from traditional networks, DTNs possess unique features, such as long latency and unstable network topology. As a result, DTNs can be widely applied to critical applications, such as space communications, disaster rescue, and battlefield communications. The brief provides a complete investigation of DTNs and their current applications, from an overview to the latest development in the area. The core issue of data forward in DTNs is tackled, including the importance of social characteristics, which is an essential feature if the mobile devices are used for human communication. Security and privacy issues in DTNs are discussed, and future work is also discussed.

  12. Synchronizing time delay systems using variable delay in coupling

    Energy Technology Data Exchange (ETDEWEB)

    Ambika, G., E-mail: g.ambika@iiserpune.ac.in [Indian Institute of Science Education and Research, Pune 411 021 (India); Amritkar, R.E., E-mail: amritkar@prl.res.in [Physical Research Laboratory, Ahmedabad 380 009 (India)

    2011-11-15

    Highlights: > Delay and anticipation in coupling function varies with system dynamics. > Delay or anticipation of the synchronized state is independent of system delay. > Stability analysis developed is quite general. > We demonstrate enhanced security in communication. > Generalized synchronization possible over a wide range of parameter mismatch. - Abstract: We present a mechanism for synchronizing time delay systems using one way coupling with a variable delay in coupling that is reset at finite intervals. We present the analysis of the error dynamics that helps to isolate regions of stability of the synchronized state in the parameter space of interest for single and multiple delays. We supplement this by numerical simulations in a standard time delay system like Mackey Glass system. This method has the advantage that it can be adjusted to be delay or anticipatory in synchronization with a time which is independent of the system delay. We demonstrate the use of this method in communication using the bi channel scheme. We show that since the synchronizing channel carries information from transmitter only at intervals of reset time, it is not susceptible to an easy reconstruction.

  13. Concurrent Delay in Construction Disputes

    DEFF Research Database (Denmark)

    Cavaleri, Sylvie Cécile

    Delay is one of the issues most frequently encountered in today’s construction industry; it causes significant economic damage to all parties involved. Construction contracts, standard and bespoke, almost invariably consider delay from a perspective of single liability. If the event causing...... solutions to the issue of concurrent delay in a comparative perspective between common and civil law systems, with an emphasis on Danish and English law....

  14. Location Estimation using Delayed Measurements

    DEFF Research Database (Denmark)

    Bak, Martin; Larsen, Thomas Dall; Nørgård, Peter Magnus

    1998-01-01

    When combining data from various sensors it is vital to acknowledge possible measurement delays. Furthermore, the sensor fusion algorithm, often a Kalman filter, should be modified in order to handle the delay. The paper examines different possibilities for handling delays and applies a new...... technique to a sensor fusion system for estimating the location of an autonomous guided vehicle. The system fuses encoder and vision measurements in an extended Kalman filter. Results from experiments in a real environment are reported...

  15. Rapid Diagnosis of Bacterial Meningitis Using a Microarray

    Directory of Open Access Journals (Sweden)

    Ren-Jy Ben

    2008-06-01

    Conclusion: The microarray method provides a more accurate and rapid diagnostic tool for bacterial meningitis compared to traditional culture methods. Clinical application of this new technique may reduce the potential risk of delay in treatment.

  16. Modeling delay in genetic networks: from delay birth-death processes to delay stochastic differential equations.

    Science.gov (United States)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Bennett, Matthew R; Josić, Krešimir; Ott, William

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  17. Single In x Ga1-x As nanowire/p-Si heterojunction based nano-rectifier diode

    Science.gov (United States)

    Sarkar, K.; Palit, M.; Guhathakurata, S.; Chattopadhyay, S.; Banerji, P.

    2017-09-01

    Nanoscale power supply units will be indispensable for fabricating next generation smart nanoelectronic integrated circuits. Fabrication of nanoscale rectifier circuits on a Si platform is required for integrating nanoelectronic devices with on-chip power supply units. In the present study, a nanorectifier diode based on a single standalone In x Ga1-x As nanowire/p-Si (111) heterojunction fabricated by metal organic chemical vapor deposition technique has been studied. The nanoheterojunction diodes have shown good rectification and fast switching characteristics. The rectification characteristics of the nanoheterojunction have been demonstrated by different standard waveforms of sinusoidal, square, sawtooth and triangular for two different frequencies of 1 and 0.1 Hz. Reverse recovery time of around 150 ms has been observed in all wave response. A half wave rectifier circuit with a simple capacitor filter has been assembled with this nanoheterojunction diode which provides 12% output efficiency. The transport of carriers through the heterojunction is investigated. The interface states density of the nanoheterojunction has also been determined. Occurrence of output waveforms incommensurate with the input is attributed to higher series resistance of the diode which is further explained considering the dimension of p-side and n-side of the junction. The sudden change of ideality factor after 1.7 V bias is attributed to recombination through interface states in space charge region. Low interface states density as well as high rectification ratio makes this heterojunction diode a promising candidate for future nanoscale electronics.

  18. Delayed visual maturation and autism.

    Science.gov (United States)

    Goodman, R; Ashby, L

    1990-09-01

    Three boys are described with a mixed developmental disorder, which so far appears to have a relatively good prognosis. Each boy presented in early infancy with visual unresponsiveness, which spontaneously resolved. This delayed visual maturation was accompanied or followed by severe autistic impairment, general developmental delay, hypotonia and clumsiness. Subsequent progress has been unexpectedly favourable, with striking improvements in language, play, social interest and social competence. Widespread, patchy delay in brain maturation could possibly account for this combination of delayed visual maturation and autism, with a good prognosis.

  19. Integrated fleet assignment and aircraft routing based on delay ...

    Indian Academy of Sciences (India)

    Airlines' expensive resources, especially aircraft, are to be optimally scheduled to cover flights of timetables. However, the irregular flight, due to bad weather, mechanical fault and so on, is inevitable.Moreover, flight delays become more severe with the rapid development of the air transport industry in China and have huge ...

  20. Fatal deterioration of delayed acute subdural hematoma after mild traumatic brain injury: two cases with brief review.

    Science.gov (United States)

    Chen, Shiwen; Xu, Chen; Yuan, Lutao; Tian, Hengli; Cao, Heli; Guo, Yan

    2014-04-01

    Both delayed posttraumatic intracerebral hemorrhage and epidural hematoma have been well described in the neurosurgical literatures. However, delayed posttraumatic acute subdural hematoma which happens more than a week with a rapid progress after mild traumatic brain injury and causes death of patient is rarely reported. We show two such cases and briefly review the literature and discuss the probable pathogenesis of their rapid progress.

  1. Delay of gratification and delay discounting in rats.

    Science.gov (United States)

    Reynolds, Brady; de Wit, Harriet; Richards, Jerry

    2002-09-30

    Delay discounting (DD) and delay of gratification (DG) are two measures of impulsive behavior often viewed as reflecting the same or equivalent processes. However, there are some key differences in the contingencies of reinforcement between the procedures that may have implications for understanding impulsivity. This study used DD and DG procedures to determine if differences in contingencies of reinforcement specified by DD and DG alters how much organisms discount the value of delayed reinforcers. Twenty-four water-deprived rats performed one of two Adjusting Amount procedures, which consisted of repeated choices between a fixed amount of water (250 &mgr;l) delivered after a delay (0, 4, 8, 16, or 32 s) and an adjusting, usually lesser amount delivered immediately. Half of the rats (n=12) performed a DD procedure designed to assess preference for immediate over delayed reinforcers in which they had discrete choices between the immediate and delayed amounts of water. A DG procedure was used for the other half of the rats (n=12). In the DG procedure rats also selected between immediate and delayed alternatives, but if they chose the delayed alternative they could switch to and receive the immediate alternative at any time during the delay to the larger reward. In the DD procedure switching responses were not reinforced but were still recorded and used for analyses. The DD functions of the two groups did not differ significantly. However, at the longer delays, the DG group made significantly fewer switching responses than the DD group. A possible role of response inhibition in the DG procedure is discussed.

  2. First order phase transition and hysteresis in a cell's maintenance of the membrane potential--An essential role for the inward potassium rectifiers.

    Science.gov (United States)

    Gallaher, Jill; Bier, Martin; van Heukelom, Jan Siegenbeek

    2010-09-01

    Hysteretic behavior is found experimentally in the transmembrane potential at low extracellular potassium in mouse lumbrical muscle cells. Adding isoprenaline to the external medium eliminates the bistable, hysteretic region. The system can be modeled mathematically and understood analytically with and without isoprenaline. Inward rectifying potassium channels appear to be essential for the bistability. Relations are derived to express the dimensions of the bistable area in terms of system parameters. The selective advantage and evolutionary origin of inward rectifying channels and hysteretic behavior is discussed. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  3. Delay dynamic equations with stability

    Directory of Open Access Journals (Sweden)

    Krueger Robert J

    2006-01-01

    Full Text Available We first give conditions which guarantee that every solution of a first order linear delay dynamic equation for isolated time scales vanishes at infinity. Several interesting examples are given. In the last half of the paper, we give conditions under which the trivial solution of a nonlinear delay dynamic equation is asymptotically stable, for arbitrary time scales.

  4. Registration Delay and Student Performance

    Science.gov (United States)

    Siefken, Jason

    2017-01-01

    Tracking the difference between the time a first-year student is allowed to register for a course and the time he or she does register for a course (a student's registration delay), we notice a negative correlation between registration delay and final grade in a course. The difference between a student who registers within the first two minutes…

  5. Delayed Reinforcement of Operant Behavior

    Science.gov (United States)

    Lattal, Kennon A.

    2010-01-01

    The experimental analysis of delay of reinforcement is considered from the perspective of three questions that seem basic not only to understanding delay of reinforcement but also, by implication, the contributions of temporal relations between events to operant behavior. The first question is whether effects of the temporal relation between…

  6. #FakeNobelDelayReasons

    CERN Document Server

    2013-01-01

    Tuesday’s hour-long delay of the Nobel Prize in Physics announcement was (and still is) quite the cause for speculation. But on the Twittersphere, it was simply the catalyst for some fantastic puns, so-bad-they're-good physics jokes and other shenanigans. Here are some of our favourite #FakeNobelDelayReasons.    

  7. Continuous generation of delayed light

    Science.gov (United States)

    Smartsev, Slava; Eger, David; Davidson, Nir; Firstenberg, Ofer

    2017-11-01

    We use a four-wave mixing process to read-out light from atomic coherence which is continuously written. The light is continuously generated after an effective delay, allowing the atomic coherence to evolve during the process. Contrary to slow-light delay, which depends on the medium optical depth, here the generation delay is determined solely by the intensive properties of the system, approaching the atomic coherence lifetime at the weak driving limit. The atomic evolution during the generation delay is further manifested in the spatial profile of the generated light due to atomic diffusion. Continuous generation of light with a long intrinsic delay can replace discrete write–read procedures when the atomic evolution is the subject of interest.

  8. Delayed radiation neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Nagashima, T.; Miyamoto, K.; Beppu, H.; Hirose, K.; Yamada, K. (Tokyo Metropolitan Neurological Hospital (Japan))

    1981-07-01

    A case of cervical plexus neuropathy was reported in association with chronic radio-dermatitis, myxedema with thyroid adenoma and epiglottic tumor. A 38-year-old man has noticed muscle weakness and wasting of the right shoulder girdle since age 33. A detailed history taking revealed a previous irradiation to the neck because of the cervical lymphadenopathy at age 10 (X-ray 3,000 rads), keroid skin change at age 19, obesity and edema since 26, and hoarseness at 34. Laryngoscopic examination revealed a tumor on the right vocal cord, diagnosed as benign papilloma by histological study. In addition, there were chronic radio-dermatitis around the neck, primary hypothyroidism with a benign functioning adenoma on the right lobe of the thyroid, the right phrenic nerve palsy and the right recurrent nerve palsy. All these lesions were considered to be the late sequellae of radiation to the neck in childhood. Other neurological signs were weakness and amyotrophy of the right shoulder girdle with patchy sensory loss, and areflexia of the right arm. Gross power was fairly well preserved in the right hand. EMG showed neurogenic changes in the tested muscles, suggesting a peripheral nerve lesion. Nerve conduction velocities were normal. No abnormal findings were revealed by myelography and spinal CT. The neurological findings of the patient were compatible with the diagnosis of middle cervical plexus palsy apparently due to late radiation effect. In the literature eight cases of post-radiation neuropathy with a long latency have been reported. The present case with the longest latency after the radiation should be included in the series of the reported cases of ''delayed radiation neuropathy.'' (author).

  9. Peak and average rectified EMG measures: which method of data reduction should be used for assessing core training exercises?

    Science.gov (United States)

    Hibbs, A E; Thompson, K G; French, D N; Hodgson, D; Spears, I R

    2011-02-01

    Core strengthening and stability exercises are fundamental for any conditioning training program. Although surface electromyography (sEMG) is used to quantify muscle activity there is a lack of research using this method to investigate the core musculature and core stability. Two types of data reduction are commonly used for sEMG; peak and average rectified EMG methods. Peak EMG has been infrequently reported in the literature with regard to the assessment of core training while even fewer studies have incorporated average rectified EMG data (ARV). The aim of the study was to establish the repeatability of peak and average rectified EMG data during core training exercises and their interrelationship. Ten male highly trained athletes (inter-subject repeatability group; age, 18 ± 1.2 years; height, 176.5 ± 3.2 cm; body mass, 71 ± 4.5 kg) and one female highly trained athlete (intra-subject repeatability group; age; 27 years old; height; 180 cm; weight; 53 kg) performed five maximal voluntary isometric contractions (MVIC) and five core exercises, chosen to represent a range of movement and muscle recruitment patterns. Peak EMG and ARV EMG were calculated for eight core muscles (rectus abdominis, RA; external oblique, EO; internal oblique, IO; multifidis, MF; latissimus dorsi, LD; longissimus, LG; gluteus maximus, GM; rectus femoris, RF) using sEMG. Average coefficient of variation (CV%) for peak EMG across all the exercises and muscles was 45%. This is in comparison to 35% for the ARV method, which was found to be a significant difference (Pexercise. Analysis of the inter-subject and intra-subject CV% values suggest that these exercises and muscles are sufficiently repeatable using sEMG. Five muscles were highly correlated (R>0.70; RA, EO, MF, GM, LG) between peak and ARV EMG suggesting, that for these core muscles, the two methods provide a similar evaluation of muscle activity. However, for other muscles (IO, RF, LD) the relationship was found to range from poor

  10. Delay of Gratification and Delay Discounting: A Unifying Feedback Model of Delay-Related Impulsive Behavior

    Science.gov (United States)

    Reynolds, Brady; Schiffbauer, Ryan

    2005-01-01

    Delay of Gratification (DG) and Delay Discounting (DD) represent two indices of impulsive behavior often treated as though they represent equivalent or the same underlying processes. However, there are key differences between DG and DD procedures, and between certain research findings with each procedure, that suggest they are not equivalent. In…

  11. A high voltage pulse generator based on silicon-controlled rectifier for field-reversed configuration experiment

    Science.gov (United States)

    Lin, Munan; Liu, Ming; Zhu, Guanghui; Wang, Yanpeng; Shi, Peiyun; Sun, Xuan

    2017-08-01

    A high voltage pulse generator based on a silicon-controlled rectifier has been designed and implemented for a field reversed configuration experiment. A critical damping circuit is used in the generator to produce the desired pulse waveform. Depending on the load, the rise time of the output trigger signal can be less than 1 μs, and the peak amplitudes of trigger voltage and current are up to 8 kV and 85 A in a single output. The output voltage can be easily adjusted by changing the voltage on a capacitor of the generator. In addition, the generator integrates an electrically floating heater circuit so it is capable of triggering either pseudosparks (TDI-type hydrogen thyratron) or ignitrons. Details of the circuits and their implementation are described in the paper. The trigger generator has successfully controlled the discharging sequence of the pulsed power supply for a field reversed configuration experiment.

  12. A High-Power-Density Single-Phase Rectifier Based on Three-Level Neutral-Point Clamped Circuits

    Directory of Open Access Journals (Sweden)

    Tao Zhou

    2017-05-01

    Full Text Available A single-phase three-level converter is suitable for medium-power applications, with an interface voltage that is higher than that of a traditional two-level configuration. The three-level neutral-point clamped converter is adopted using four switches in each bridge arm, which, compared to a two-level rectifier, leads to less voltage stress, a lower switching frequency, and switching loss on switches. The transient current control strategy is designed to control the active power. The single-phase space vector pulse width modulation (SVPWM with a voltage balance strategy is designed to solve the neutral point voltage fluctuation problem and keep the dc-link voltage stable. A 1.3 kW high-power-density prototype based on SiC MOSFET was built and tested. The experimental results verified the high performance of steady-state and dynamic responses.

  13. Investigation on a Novel Discontinuous Pulse-Width Modulation Algorithm for Single-phase Voltage Source Rectifier

    DEFF Research Database (Denmark)

    Qu, Hao; Yang, Xijun; Guo, Yougui

    2014-01-01

    Single-phase voltage source converter (VSC) is an important power electronic converter (PEC), including single-phase voltage source inverter (VSI), single-phase voltage source rectifier (VSR), single-phase active power filter (APF) and single-phase grid-connection inverter (GCI). Single-phase VSC......-sequence component injection, in order to reduce power loss and increased overall efficiency. And then by reconstructing the other two phase input voltages and currents, the transformation from stationary frame (abc) to rotating frame (dq frame) is designed. Finally, a PI regulator based controller for single......-phase VSR is analyzed and simulated by means of MATLAB/SIMULINK by using the presented DPWM and dq transformation. The simulation results show the validation of the above DPWM algorithm and control theory....

  14. A Fuzzy-Logic-Based Controller for Three-Phase PWM Rectifier With Unity Power Factor Operation

    Directory of Open Access Journals (Sweden)

    A. Bouafia

    2008-03-01

    Full Text Available In this paper, direct power control (DPC of three-phase PWM rectifiers based on fuzzy logic controller is presented, without line voltage sensors. The control technique is built upon the ideas of the well known direct torque control (DTC for induction motors. The instantaneous active and reactive powers, directly controlled by selecting the optimum state of the converter, are used as the PWM control variables instead of the phase line currents being used. The proposed fuzzy logic controller presents the advantage to be based on linguistic description and does not require a mathematical model of the system. The controller ensures a good regulation of the output voltage, and guarantees the power factor close to one. The simulation results show that the designed fuzzy controller has a good dynamic behavior, a good rejection of impact load disturbance, and is very robust.

  15. Time Delay in Molecular Photoionization

    CERN Document Server

    Hockett, P; Villeneuve, D M; Corkum, P B

    2015-01-01

    Time-delays in the photoionization of molecules are investigated. As compared to atomic ionization, the time-delays expected from molecular ionization present a much richer phenomenon, with a strong spatial dependence due to the anisotropic nature of the molecular scattering potential. We investigate this from a scattering theory perspective, and make use of molecular photoionization calculations to examine this effect in representative homonuclear and hetronuclear diatomic molecules, nitrogen and carbon monoxide. We present energy and angle-resolved maps of the Wigner delay time for single-photon valence ionization, and discuss the possibilities for experimental measurements.

  16. Rectifying structure with high voltage operation based on CuBO{sub 2} as an UV photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Soylu, M., E-mail: soylum74@yahoo.com [Department of Physics, Faculty of Sciences and Arts, Bingol University, Bingol (Turkey); Al-Ghamdi, Ahmed A. [Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Omran, Saad Bin [Department of Physics and Astronomy, College of Science, King Saud University, Riyadh (Saudi Arabia); Yakuphanoglu, F. [Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Department of Physics, Faculty of Science, Firat University, Elazig 23169 (Turkey)

    2014-12-25

    Highlight: • We have fabricated nanostructured CuBO{sub 2} by spin coating on the p-Si. • CuBO{sub 2}/p-Si diode is a new rectifying structure with photosensing. • The photocurrent in the reverse bias voltage is increased by increasing photo-illumination intensity. • CuBO{sub 2}/p-Si/Al diode is a candidate for producing high tension protection circuit. - Abstract: CuBO{sub 2}/p-Si diode is a new rectifying structure with photosensing, which is a candidate for producing high voltage protection circuit in electronic application. It has been seen that the photocurrent in the reverse bias I–V characteristic is strongly increased by photo-illumination. It is believed that the combination of thin CuBO{sub 2} layer and p-Si will provide high voltage protection level, which does not exist for conventional Si diodes. The capacitance and conductance–voltage characteristics were measured at various frequencies. The results indicate that the electrical parameters of CuBO{sub 2}/p-Si diode are affected by the series resistance and interface states. The optical properties of the CuBO{sub 2} thin film were analyzed by UV–vis–NIR spectrophotometry and FTIR studies. The optical band gap of the CuBO{sub 2} is located in the ultraviolet (UV) range. In this spectral range, the B-O-B bonds and relationship between Cu{sup 2+}–O are confirmed.

  17. A Multi-Pulse Front-End Rectifier System with Electronic Phase-Shifting for Harmonic Mitigation in Motor Drive Applications

    DEFF Research Database (Denmark)

    Zare, Firuz; Davari, Pooya; Blaabjerg, Frede

    2016-01-01

    In this paper, an electronic phase-shifting strategy has been optimized for a multi-parallel configuration of line-commutated rectifiers with a common dc-bus voltage used in motor drive application. This feature makes the performance of the system independent of the load profile and maximizes its...

  18. Unipolar resistive switching with forming-free and self-rectifying effects in Cu/HfO2/n-Si devices

    Directory of Open Access Journals (Sweden)

    M. J. Wang

    2016-02-01

    Full Text Available One of the most effective methods integrating self-rectifying RRAM is alleviating sneak current in crossbar architecture. In this work, to investigate RRAMs with excellent properties of self-rectifying effect, simple Cu/HfO2/n-Si tri-layer devices are fabricated and investigated through I − V characteristic measurement. The experimental results demonstrate that the device exhibits forming-free behavior and a remarkable rectifying effect in low resistance state (LRS with rectification ratio of 104 at ±1 V, as well as considerable OFF/ON ratio (resistive switching window of 104 at 1 V. The formation and annihilation of localized Cu conductive filament plays a key role in the resistive switching between low resistance state (LRS and high resistance state (HRS. In addition, intrinsic rectifying effect in LRS attributes to the Schottky contact between Cu filament and n-Si electrode. Furthermore, satisfactory switching uniformity of cycles and devices is observed. As indicated by the results, Cu/HfO2/n-Si devices have a high potential for high-density storage practical application due to its excellent properties.

  19. MODELLING OF PROCESS OF COMPRESSION OF STEAMS OF A RECTIFIED ALCOHOL IN THE SCHEMA OF AN ALCOHOLIC COLUMN WITH A HEAT PUMP

    Directory of Open Access Journals (Sweden)

    T. G. Korotkova

    2012-01-01

    Full Text Available The use of thermodynamic relations and equation of state of Redlich-Kwong, obtaining the approximation of the molar volume dependence on temperature and pressure, ideal gas heat capacity on temperature for the modeling of vapor compression rectified alcohol. Energy analysis scheme alcohol column with a heat pump and its comparison with the standard rectification plant.

  20. Energy-efficient scheduling under delay constraints for wireless networks

    CERN Document Server

    Berry, Randal; Zafer, Murtaza

    2012-01-01

    Packet delay and energy consumption are important considerations in wireless and sensor networks as these metrics directly affect the quality of service of the application and the resource consumption of the network; especially, for a rapidly growing class of real-time applications that impose strict restrictions on packet delays. Dynamic rate control is a novel technique for adapting the transmission rate of wireless devices, almost in real-time, to opportunistically exploit time-varying channel conditions as well as changing traffic patterns. Since power consumption is not a linear function

  1. Fundamentals of Delayed Coking Joint Industry Project

    Energy Technology Data Exchange (ETDEWEB)

    Michael Volk; Keith Wisecarver

    2004-09-26

    Delayed coking evolved steadily over the early to mid 1900s to enable refiners to convert high boiling, residual petroleum fractions to light products such as gasoline. Pound for pound, coking is the most energy intensive of any operation in a modern refinery. Large amounts of energy are required to heat the thick, poor-quality petroleum residuum to the 900 to 950 degrees F required to crack the heavy hydrocarbon molecules into lighter, more valuable products. One common misconception of delayed coking is that the product coke is a disadvantage. Although coke is a low valued (near zero economic value) byproduct, compared to transportation fuels, there is a significant worldwide trade and demand for coke as it is an economical fuel. Coke production has increased steadily over the last ten years, with further increases forecast for the foreseeable future. Current domestic production is near 111,000 tons per day. A major driving force behind this increase is the steady decline in crude quality available to refiners. Crude slates are expected to grow heavier with higher sulfur contents while environmental restrictions are expected to significantly reduce the demand for high-sulfur residual fuel oil. Light sweet crudes will continue to be available and in even greater demand than they are today. Refiners will be faced with the choice of purchasing light sweet crudes at a premium price, or adding bottom of the barrel upgrading capability, through additional new investments, to reduce the production of high-sulfur residual fuel oil and increase the production of low-sulfur distillate fuels. A second disadvantage is that liquid products from cokers frequently are unstable, i.e., they rapidly form gum and sediments. Because of intermediate investment and operating costs, delayed coking has increased in popularity among refiners worldwide. Based on the 2000 Worldwide Refining Survey published in the Oil and Gas, the delayed coking capacity for 101 refineries around the world

  2. Fundamentals of Delayed Coking Joint Industry Project

    Energy Technology Data Exchange (ETDEWEB)

    Michael Volk; Keith Wisecarver

    2003-09-26

    Delayed coking evolved steadily over the early to mid 1900s to enable refiners to convert high boiling, residual petroleum fractions to light products such as gasoline. Pound for pound, coking is the most energy intensive of any operation in a modern refinery. Large amounts of energy are required to heat the thick, poor-quality petroleum residuum to the 900 to 950 degrees F required to crack the heavy hydrocarbon molecules into lighter, more valuable products. One common misconception of delayed coking is that the product coke is a disadvantage. Although coke is a low valued (near zero economic value) byproduct, compared to transportation fuels, there is a significant worldwide trade and demand for coke as it is an economical fuel. Coke production has increased steadily over the last ten years, with further increases forecast for the foreseeable future. Current domestic production is near 111,000 tons per day. A major driving force behind this increase is the steady decline in crude quality available to refiners. Crude slates are expected to grow heavier with higher sulfur contents while environmental restrictions are expected to significantly reduce the demand for high-sulfur residual fuel oil. Light sweet crudes will continue to be available and in even greater demand than they are today. Refiners will be faced with the choice of purchasing light sweet crudes at a premium price, or adding bottom of the barrel upgrading capability, through additional new investments, to reduce the production of high-sulfur residual fuel oil and increase the production of low-sulfur distillate fuels. A second disadvantage is that liquid products from cokers frequently are unstable, i.e., they rapidly form gum and sediments. Because of intermediate investment and operating costs, delayed coking has increased in popularity among refiners worldwide. Based on the 2000 Worldwide Refining Survey published in the Oil and Gas, the delayed coking capacity for 101 refineries around the world

  3. DELAYED PUBERTY: A LATE DIAGNOSIS

    Directory of Open Access Journals (Sweden)

    Helena Ferreira

    2017-04-01

    Discussion/Conclusion: We aimed to aware Crohn’s disease as one of the causes of pubertal and growth delay, highlighting the need for early diagnosis and therapy, in order to reach a favorable pubertal development.

  4. Delays and networked control systems

    CERN Document Server

    Hetel, Laurentiu; Daafouz, Jamal; Johansson, Karl

    2016-01-01

    This edited monograph includes state-of-the-art contributions on continuous time dynamical networks with delays. The book is divided into four parts. The first part presents tools and methods for the analysis of time-delay systems with a particular attention on control problems of large scale or infinite-dimensional systems with delays. The second part of the book is dedicated to the use of time-delay models for the analysis and design of Networked Control Systems. The third part of the book focuses on the analysis and design of systems with asynchronous sampling intervals which occur in Networked Control Systems. The last part of the book exposes several contributions dealing with the design of cooperative control and observation laws for networked control systems. The target audience primarily comprises researchers and experts in the field of control theory, but the book may also be beneficial for graduate students. .

  5. Parental Discipline and Delayed Gratification

    Science.gov (United States)

    Weller, Leonard; Berkowitz, Edith

    1975-01-01

    It was hypothesized that children brought up under coercive power would be more likely to exhibit immediate gratification, whereas children brought up under noncoercive power would be more likely to delay gratification. The hypothesis was confirmed. (Author)

  6. Fractional variational principles with delay

    Science.gov (United States)

    Baleanu, Dumitru; Maaraba Abdeljawad, Thabet; Jarad, Fahd

    2008-08-01

    The fractional variational principles within Riemann-Liouville fractional derivatives in the presence of delay are analyzed. The corresponding Euler-Lagrange equations are obtained and one example is analyzed in detail.

  7. Fractional variational principles with delay

    Energy Technology Data Exchange (ETDEWEB)

    Baleanu, Dumitru; Abdeljawad, Thabet Maaraba; Jarad, Fahd [Department of Mathematics and Computer Sciences, Faculty of Arts and Sciences, Cankaya University, 06530 Ankara (Turkey)], E-mail: dumitru@cankaya.edu.tr, E-mail: baleanu@venus.nipne.ro

    2008-08-08

    The fractional variational principles within Riemann-Liouville fractional derivatives in the presence of delay are analyzed. The corresponding Euler-Lagrange equations are obtained and one example is analyzed in detail.

  8. EAMJ Delayed April 10.indd

    African Journals Online (AJOL)

    2010-04-04

    Apr 4, 2010 ... INTRODUCTION. Breast cancer remains a leading cause of death of ... ABSTRACT. Objective: To determine the extent and nature of delayed presentation of patients .... symptomatic breast cancer: a systematic review. Lancet.

  9. Systematics in delayed neutron yields

    Energy Technology Data Exchange (ETDEWEB)

    Ohsawa, Takaaki [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.

    1998-03-01

    An attempt was made to reproduce the systematic trend observed in the delayed neutron yields for actinides on the basis of the five-Gaussian representation of the fission yield together with available data sets for delayed neutron emission probability. It was found that systematic decrease in DNY for heavier actinides is mainly due to decrease of fission yields of precursors in the lighter side of the light fragment region. (author)

  10. Measuring information-transfer delays.

    Directory of Open Access Journals (Sweden)

    Michael Wibral

    Full Text Available In complex networks such as gene networks, traffic systems or brain circuits it is important to understand how long it takes for the different parts of the network to effectively influence one another. In the brain, for example, axonal delays between brain areas can amount to several tens of milliseconds, adding an intrinsic component to any timing-based processing of information. Inferring neural interaction delays is thus needed to interpret the information transfer revealed by any analysis of directed interactions across brain structures. However, a robust estimation of interaction delays from neural activity faces several challenges if modeling assumptions on interaction mechanisms are wrong or cannot be made. Here, we propose a robust estimator for neuronal interaction delays rooted in an information-theoretic framework, which allows a model-free exploration of interactions. In particular, we extend transfer entropy to account for delayed source-target interactions, while crucially retaining the conditioning on the embedded target state at the immediately previous time step. We prove that this particular extension is indeed guaranteed to identify interaction delays between two coupled systems and is the only relevant option in keeping with Wiener's principle of causality. We demonstrate the performance of our approach in detecting interaction delays on finite data by numerical simulations of stochastic and deterministic processes, as well as on local field potential recordings. We also show the ability of the extended transfer entropy to detect the presence of multiple delays, as well as feedback loops. While evaluated on neuroscience data, we expect the estimator to be useful in other fields dealing with network dynamics.

  11. Language Delays in Toddlers: Information for Parents

    Science.gov (United States)

    ... Stages Listen Español Text Size Email Print Share Language Delays in Toddlers: Information for Parents Page Content ... situation or repeats scripts from TV Delays in language Delays in language are the most common types ...

  12. RECTIFICADORES CA/CC TIRISTORIZADOS CON FORMAS DE ONDA DE ALTA CALIDAD THYRISTOR-BASED AC/DC RECTIFIERS WITH HIGH-QUALITY WAVEFORMS

    Directory of Open Access Journals (Sweden)

    Miguel Villablanca

    2010-04-01

    Full Text Available En este artículo un método y un aparato son aplicados a distintas configuraciones de rectificadores ca/cc tiristorizados para reducir la distorsión de las corrientes en el lado de C.A. La carga puede ser inductiva o capacitiva. La tecnología consiste en darle una adecuada forma de onda a la corriente en el lado de C.C. a través de dos interruptores de conmutación forzada. Esta forma de onda lograda en la corriente en el lado de C.C. se refleja en la forma de onda de las corrientes en el lado de C.A., las cuales se transforman en perfectas ondas senoidales. El circuito de control es simple y es también capaz de manejar variaciones rápidas de corriente de carga y fallas en los interruptores de conmutación forzada. La conducción simultánea de los tiristores del puente rectificador es eliminada completamente. La validación experimental de la tecnología es mostrada a través de un prototipo de laboratorio de 400 V, 50 Hz y 30 KVA.In this paper both a method and apparatus are applied to different configurations of thyristor-based ac/dc rectifiers to reduce the distortion of currents flowing from the ac supply. The load may be either inductive or capacitive. The technology involves an accurate shaping of the dc current by using two self-commutated switches. This dc-current shaping is reflected back into the shaping of the ac input currents, which become pure sine waves. The control circuit is simple, and also able to deal with both rapid load variations and failures in the self-commutated switches. Furthermore, the overlap conduction of bridge thyristors is eliminated completely. Experimental verification is provided from a 400-V 50-Hz 30-kVA laboratory prototype.

  13. H∞ Control of Four-Wheel-Independent-Drive Electric Vehicles with Random Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    Gang Qin

    2015-01-01

    Full Text Available The random time-varying delays would reduce control performance and even deteriorate the EV system. To deal with random time-varying delays and achieve a real-time steady-state response, considering randomness of delay and a rapid response, an H∞-based delay-tolerant linear quadratic regulator (LQR control method based on Taylor series expansion is proposed in this paper. The results of cosimulations with Simulink and CarSim demonstrate the effectiveness of the proposed controller through the control performance of yaw rate, sideslip angle, and the running track. Moreover, the results of comparison with the other controller illustrate the strength of explicitly.

  14. Impulsive Rats Exhibit Blunted Dopamine Release Dynamics during a Delay Discounting Task Independent of Cocaine History

    Science.gov (United States)

    Moschak, Travis M.

    2017-01-01

    Abstract The inability to wait for a large, delayed reward when faced with a small, immediate one, known as delay discounting, has been implicated in a number of disorders including substance abuse. Individual differences in impulsivity on the delay discounting task are reflected in differences in neural function, including in the nucleus accumbens (NAc) core. We examined the role of a history of cocaine self-administration, as well as individual differences in impulsivity, on rapid dopamine (DA) release dynamics in the NAc core. Rats with a history of cocaine or water/saline self-administration were tested on delay discounting while being simultaneously assayed for rapid DA release using electrochemical methods. In controls, we found that cue DA release was modulated by reward delay and magnitude, consistent with prior reports. A history of cocaine had no effect on either delay discounting or DA release dynamics. Nonetheless, independent of drug history, individual differences in impulsivity were related to DA release in the NAc core. First, high impulsive animals exhibited dampened cue DA release during the delay discounting task. Second, reward delay and magnitude in high impulsive animals failed to robustly modulate changes in cue DA release. Importantly, these two DAergic mechanisms were uncorrelated with each other and, together, accounted for a high degree of variance in impulsive behavior. Collectively, these findings demonstrate two distinct mechanisms by which rapid DA signaling may influence impulsivity, and illustrate the importance of NAc core DA release dynamics in impulsive behavior. PMID:28451642

  15. Delayed Transient Post-Traumatic Quadriplegia

    Directory of Open Access Journals (Sweden)

    Khaloud Al-Shaaibi

    2015-03-01

    Full Text Available Transient neurological deficit following cervical trauma have been reported following sports injuries, and has been referred to as cervical cord neurapraxia. The so-called "whiplash injuries" following minor motor vehicle collisions usually do not produce any neurological deficit. Here we report the case of a whiplash type of injury presenting with a delayed onset neurological deficit, which was followed by rapid and complete recovery. The patient, an otherwise healthy 34-year-old male, attended the emergency department of Sultan Qaboos University Hospital following a rear-end motor vehicle collision. We present images showing degenerative disc disease causing spinal canal narrowing and mild cord compression in the patient, but no spinal instability. Differential diagnoses are also discussed.

  16. HAMLET treatment delays bladder cancer development.

    Science.gov (United States)

    Mossberg, Ann-Kristin; Hou, Yuchuan; Svensson, Majlis; Holmqvist, Bo; Svanborg, Catharina

    2010-04-01

    HAMLET is a protein-lipid complex that kills different types of cancer cells. Recently we observed a rapid reduction in human bladder cancer size after intravesical HAMLET treatment. In this study we evaluated the therapeutic effect of HAMLET in the mouse MB49 bladder carcinoma model. Bladder tumors were established by intravesical injection of MB49 cells into poly L-lysine treated bladders of C57BL/6 mice. Treatment groups received repeat intravesical HAMLET instillations and controls received alpha-lactalbumin or phosphate buffer. Effects of HAMLET on tumor size and putative apoptotic effects were analyzed in bladder tissue sections. Whole body imaging was used to study HAMLET distribution in tumor bearing mice compared to healthy bladder tissue. HAMLET caused a dose dependent decrease in MB49 cell viability in vitro. Five intravesical HAMLET instillations significantly decreased tumor size and delayed development in vivo compared to controls. TUNEL staining revealed selective apoptotic effects in tumor areas but not in adjacent healthy bladder tissue. On in vivo imaging Alexa-HAMLET was retained for more than 24 hours in the bladder of tumor bearing mice but not in tumor-free bladders or in tumor bearing mice that received Alexa-alpha-lactalbumin. Results show that HAMLET is active as a tumoricidal agent and suggest that topical HAMLET administration may delay bladder cancer development. Copyright (c) 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  17. Delayed effects of cortisol enhance fear memory of trace conditioning.

    Science.gov (United States)

    Cornelisse, Sandra; van Ast, Vanessa A; Joëls, Marian; Kindt, Merel

    2014-02-01

    Corticosteroids induce rapid non-genomic effects followed by slower genomic effects that are thought to modulate cognitive function in opposite and complementary ways. It is presently unknown how these time-dependent effects of cortisol affect fear memory of delay and trace conditioning. This distinction is of special interest because the neural substrates underlying these types of conditioning may be differently affected by time-dependent cortisol effects. Delay conditioning is predominantly amygdala-dependent, while trace conditioning additionally requires the hippocampus. Here, we manipulated the timing of cortisol action during acquisition of delay and trace fear conditioning, by randomly assigning 63 men to one of three possible groups: (1) receiving 10mg hydrocortisone 240 min (slow cort) or (2) 60 min (rapid cort) before delay and trace acquisition, or (3) placebo at both times, in a double-blind design. The next day, we tested memory for trace and delay conditioning. Fear potentiated startle responses, skin conductance responses and unconditioned stimulus expectancy scores were measured throughout the experiment. The fear potentiated startle data show that cortisol intake 240 min before actual fear acquisition (slow cort) uniquely strengthened subsequent trace conditioned memory. No effects of cortisol delivery 60 min prior to fear acquisition were found on any measure of fear memory. Our findings emphasize that slow, presumably genomic, but not more rapid effects of corticosteroids enhance hippocampal-dependent fear memories. On a broader level, our findings underline that basic experimental research and clinically relevant pharmacological treatments employing corticosteroids should acknowledge the timing of corticosteroid administration relative to the learning phase, or therapeutic intervention. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Role of the anomalous rectifier in determining membrane potentials of mouse muscle fibres at low extracellular K+.

    Science.gov (United States)

    Siegenbeek van Heukelom, J

    1991-01-01

    1. The membrane potential (Vm) of fibres of the extensor digitorum longus (EDL) of the mouse, measured at 35 degrees C and with extracellular potassium concentration (K+o) 5.7 mM, was Vm = -76 mV. 2. Lowering K+o below 1 mM could lead to either a hyperpolarizing or a depolarizing response. When Vm was lower than -75.5 mV in the control medium, a reduction of K+o to 0.76 mM led to a hyperpolarization of Vm (-95.0 +/- 0.7 mV, n = 40); otherwise a depolarization occurred (Vm = -47.2 +/- 1.1 mV, n = 21). 3. The difference in Vm responses did not correlate consistently with functional differences in cell types, as cells that originally hyperpolarized, could later depolarize. 4. The observed phenomena could be explained if the properties of the anomalous rectifier, AR (or inward-going rectifier), are considered to be similar to those observed in cardiac cells. 5. Apparently caesium acted as a competitive inhibitor; when the inhibition was strong enough the non-linear properties of the AR regeneratively amplified the depolarization to the full-blown depolarized state (Vm = -46.7 +/- 1.3 mV, n = 15). 6. Ouabain (10(-4) M) reduced Vm (to -45 +/- 3 mV, n = 5) and reduced dramatically the selectivity of the cell membrane for potassium over sodium. These effects could be reversed readily by washing out the ouabain. 7. Adrenaline (2 microM) added to the medium hyperpolarized Vm (delta Vm = -4.6 +/- 1.4 mV, n = 9) and increased the changes induced by lowered K+o (from -14.3 +/- 0.5 mV, n = 5 to -18.0 +/- 0.8 mV, n = 9); the cells that originally depolarized when K+o was lowered could hyperpolarize after adrenaline addition. PMID:2023129

  19. Stochastic modelling of train delays and delay propagation in stations

    NARCIS (Netherlands)

    Yuan, J.

    2006-01-01

    A trade-off exists between efficiently utilizing the capacity of railway networks and improving the reliability and punctuality of train operations. This dissertation presents a new analytical probability model based on blocking time theory which estimates the knock-on delays of trains caused by

  20. Justice Delayed is Justice Denied

    Directory of Open Access Journals (Sweden)

    Naomi Burstyner

    2014-10-01

    Full Text Available This paper explores issues in the justice system that are related to timeliness and its interconnectedness to the definition of delay, whilst considering the impact of delay on the experience of the justice system user.Historical acknowledgements recognise the perspective of the accused or the disputant, and suggest that for a person seeking justice, the time taken for resolution of their issue is critical to the justice experience of this person and can render their treatment wholly ‘unjust’ in circumstances where closure takes ‘too long’.

  1. 49 CFR 236.563 - Delay time.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time. ...

  2. Rapid, generalized adaptation to asynchronous audiovisual speech.

    Science.gov (United States)

    Van der Burg, Erik; Goodbourn, Patrick T

    2015-04-07

    The brain is adaptive. The speed of propagation through air, and of low-level sensory processing, differs markedly between auditory and visual stimuli; yet the brain can adapt to compensate for the resulting cross-modal delays. Studies investigating temporal recalibration to audiovisual speech have used prolonged adaptation procedures, suggesting that adaptation is sluggish. Here, we show that adaptation to asynchronous audiovisual speech occurs rapidly. Participants viewed a brief clip of an actor pronouncing a single syllable. The voice was either advanced or delayed relative to the corresponding lip movements, and participants were asked to make a synchrony judgement. Although we did not use an explicit adaptation procedure, we demonstrate rapid recalibration based on a single audiovisual event. We find that the point of subjective simultaneity on each trial is highly contingent upon the modality order of the preceding trial. We find compelling evidence that rapid recalibration generalizes across different stimuli, and different actors. Finally, we demonstrate that rapid recalibration occurs even when auditory and visual events clearly belong to different actors. These results suggest that rapid temporal recalibration to audiovisual speech is primarily mediated by basic temporal factors, rather than higher-order factors such as perceived simultaneity and source identity. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  3. Gas-Induced Rectified Motion of a Solid Object in a Liquid-Filled Housing during Vibration: Analysis and Experiments

    Science.gov (United States)

    Torczynski, J. R.; O'Hern, T. J.; Clausen, J. R.; Koehler, T. P.

    2017-11-01

    The motion of a solid object (a piston) that fits closely within a housing filled with viscous liquid is studied. If a small amount of gas is introduced and the system is subjected to axial vibration, then the piston exhibits rectified motion when the drag on the piston depends on its position within the housing. An idealized system, in which the piston is suspended freely between two springs and the gas is replaced with two compressible bellows, is analyzed theoretically and studied experimentally. For a given vibration amplitude or frequency, the piston either remains near its original position (``up'') or moves to a different position (``down''), where its spring suspension is compressed. Analytical and experimental regime maps of the amplitudes and frequencies at which the piston is up or down are in good agreement. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

  4. Molecular and functional characterization of Anopheles gambiae inward rectifier potassium (Kir1) channels: a novel role in egg production.

    Science.gov (United States)

    Raphemot, Rene; Estévez-Lao, Tania Y; Rouhier, Matthew F; Piermarini, Peter M; Denton, Jerod S; Hillyer, Julián F

    2014-08-01

    Inward rectifier potassium (Kir) channels play essential roles in regulating diverse physiological processes. Although Kir channels are encoded in mosquito genomes, their functions remain largely unknown. In this study, we identified the members of the Anopheles gambiae Kir gene family and began to investigate their function. Notably, we sequenced the A. gambiae Kir1 (AgKir1) gene and showed that it encodes all the canonical features of a Kir channel: an ion pore that is composed of a pore helix and a selectivity filter, two transmembrane domains that flank the ion pore, and the so-called G-loop. Heterologous expression of AgKir1 in Xenopus oocytes revealed that this gene encodes a functional, barium-sensitive Kir channel. Quantitative RT-PCR experiments then showed that relative AgKir1 mRNA levels are highest in the pupal stage, and that AgKir1 mRNA is enriched in the adult ovaries. Gene silencing of AgKir1 by RNA interference did not affect the survival of female mosquitoes following a blood meal, but decreased their egg output. These data provide evidence for a new role of Kir channels in mosquito fecundity, and further validates them as promising molecular targets for the development of a new class of mosquitocides to be used in vector control. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. G-Protein-Gated Inwardly Rectifying Potassium (GIRK) Channel Subunit 3 Knock-Out Mice Show Enhanced Ethanol Reward

    Science.gov (United States)

    Tipps, Megan E.; Raybuck, Jonathan D.; Kozell, Laura B.; Lattal, K. Matthew; Buck, Kari J.

    2016-01-01

    Background G protein-coupled inwardly rectifying potassium (GIRK) channels contribute to the effects of a number of drugs of abuse, including ethanol. However, the roles of individual subunits in the rewarding effects of ethanol are poorly understood. Methods We compare conditioned place preference (CPP) in GIRK3 subunit knock-out (GIRK3−/−), heterozygote (GIRK3+/−), and wild-type (WT) mice. In addition, the development of locomotor tolerance/sensitization and the effects of ethanol intoxication on associative learning (fear conditioning) are also assessed. Results Our data show significant ethanol CPP in GIRK3−/− and GIRK3+/− mice, but not in the WT littermates. In addition, we demonstrate that these effects are not due to differences in ethanol metabolism, the development of ethanol tolerance/sensitivity, or associative learning abilities. While there were no consistent genotype differences in the fear conditioning assay, our data do show a selective sensitization of the impairing effects of ethanol intoxication on contextual learning, but no effect on cued learning. Conclusions These findings suggest that GIRK3 plays a role in ethanol reward. Further, the selectivity of this effect suggests that GIRK channels could be an effective therapeutic target for the prevention and/or treatment of alcoholism. PMID:27012303

  6. A G-protein-activated inwardly rectifying K+ channel (GIRK4) from human hippocampus associates with other GIRK channels.

    Science.gov (United States)

    Spauschus, A; Lentes, K U; Wischmeyer, E; Dissmann, E; Karschin, C; Karschin, A

    1996-02-01

    Transcripts of a gene, GIRK4, that encodes for a 419-amino-acid protein and shows high structural similarity to other subfamily members of G-protein-activated inwardly rectifying K+ channels (GIRK) have been identified in the human hippocampus. When expressed in Xenopus oocytes, GIRK4 yielded functional GIRK channels with activity that was enhanced by the stimulation of coexpressed serotonin 1A receptors. GIRK4 potentiated basal and agonist-induced currents mediated by other GIRK channels, possibly because of channel heteromerization. Despite the structural similarity to a putative rat KATP channel, no ATP sensitivity or KATP-typical pharmacology was observed for GIRK4 alone or GIRK4 transfected in conjunction with other GIRK channels in COS-7 cells. In rat brain, GIRK4 is expressed together with three other subfamily members, GIRK1-3, most likely in identical hippocampal neurons. Thus, heteromerization or an unknown molecular interaction may cause the physiological diversity observed within this class of K+ channels.

  7. Balanced Current Control Strategy for Current Source Rectifier Stage of Indirect Matrix Converter under Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Yeongsu Bak

    2016-12-01

    Full Text Available This paper proposes a balanced current control strategy for the current source rectifier (CSR stage of an indirect matrix converter (IMC under unbalanced grid voltage conditions. If the three-phase grid connected to the voltage source inverter (VSI of the IMC has unbalanced voltage conditions, it affects the currents of the CSR stage and VSI stage, and the currents are distorted. Above all, the distorted currents of the CSR stage cause instability in the overall system, which can affect the life span of the system. Therefore, in this paper, a control strategy for balanced currents in the CSR stage is proposed. To achieve balanced currents in the CSR stage, the VSI stage should receive DC power without ripple components from the CSR stage. This is implemented by controlling the currents in the VSI stage. Therefore, the proposed control strategy decouples the positive and negative phase-sequence components existing in the unbalanced voltages and currents of the VSI stage. Using the proposed control strategy under unbalanced grid voltage conditions, the stability and life span of the overall system can be improved. The effectiveness of the proposed control strategy is verified by simulation and experimental results.

  8. Harmonic Filtering Performance of a Hybrid Active Filter for a Three-Phase 12-Pulse Diode Rectifier

    Science.gov (United States)

    Isozaki, Kohei; Akagi, Hirofumi

    This paper describes a hybrid active filter for harmonic-current compensation of a three-phase 12-pulse diode rectifier used as the front end of a medium-voltage motor drive system. This hybrid filter is characterized by the direct series connection of a simple LC filter and a small-rated active filter. This circuit configuration brings low cost, small size, and light weight to the hybrid filter. The authors design, construct, and test a three-phase experimental system rated at 400V and 15kW, which is a downscaled model of the medium-voltage motor drive system. In this experiment, the LC filter is tuned to the 11th harmonic frequency, and the active filter is based on a three-level diode-clamped PWM converter with a dc capacitor voltage as low as 28V. This hybrid filter is connected on either the first or fourth winding of a line-frequency transformer with a first Δ-winding voltage of 400V in the primary, and a second Δ-winding voltage of 220V, a third Y-winding voltage of 220V, and a fourth Δ-winding voltage of 400V in the secondary. Experimental results show that the hybrid filter performs satisfactory filtering in a range from the no-load to full-load conditions.

  9. Rectified photocurrent in a planar ITO/graphene/ITO photodetector on SiC by local irradiation of ultraviolet light

    Science.gov (United States)

    Yang, Junwei; Guo, Liwei; Huang, Jiao; Mao, Qi; Guo, Yunlong; Jia, Yuping; Peng, Tonghua; Chen, Xiaolong

    2017-10-01

    A rectified photocurrent behaviour is demonstrated in a simple planar structure of ITO-graphene-ITO formed on a SiC substrate when an ultraviolet (UV) light is locally incident on one of the edges between the graphene and ITO electrode. The photocurrent has similar characteristics as those of a vertical structure graphene/semiconductor junction photodiode, but is clearly different from those found in a planar structure metal-graphene-metal device. Furthermore, the device behaves multi-functionally as a photodiode with sensitive UV photodetection capability (responsivity of 11.7 mA W-1 at 0.3 V) and a self-powered UV photodetector (responsivity of 4.4 mA W-1 at zero bias). Both features are operative in a wide dynamic range and with a fast speed of response in about gigahertz. The linear I-V behaviour with laser power at forward bias and cutoff at reverse bias leads to a conceptual photodiode, which is compatible with modern semiconductor planar device architecture. This paves a potential way to realize ultrafast graphene planar photodiodes for monolithic integration of graphene-based devices on the same SiC substrate.

  10. Synergistic activation of G protein-gated inwardly rectifying potassium channels by cholesterol and PI(4,5)P2.

    Science.gov (United States)

    Bukiya, Anna N; Rosenhouse-Dantsker, Avia

    2017-07-01

    G-protein gated inwardly rectifying potassium (GIRK or Kir3) channels play a major role in the control of the heart rate, and require the membrane phospholipid phosphatidylinositol-bis-phosphate (PI(4,5)P 2 ) for activation. Recently, we have shown that the activity of the heterotetrameric Kir3.1/Kir3.4 channel that underlies atrial K ACh currents was enhanced by cholesterol. Similarly, the activities of both the Kir3.4 homomer and its active pore mutant Kir3.4* (Kir3.4_S143T) were also enhanced by cholesterol. Here we employ planar lipid bilayers to investigate the crosstalk between PI(4,5)P 2 and cholesterol, and demonstrate that these two lipids act synergistically to activate Kir3.4* currents. Further studies using the Xenopus oocytes heterologous expression system suggest that PI(4,5)P 2 and cholesterol act via distinct binding sites. Whereas PI(4,5)P 2 binds to the cytosolic domain of the channel, the putative binding region of cholesterol is located at the center of the transmembrane domain overlapping the central glycine hinge region of the channel. Together, our data suggest that changes in the levels of two key membrane lipids - cholesterol and PI(4,5)P 2 - could act in concert to provide fine-tuning of Kir3 channel function. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Reduction of the heat leak in superconducting system at half-wave-rectified current mode by peltier current lead

    CERN Document Server

    Yamaguchi, T; Nakamura, K; Yamaguchi, S; Hasegawa, Y

    2002-01-01

    Experiments of Peltier current lead (PCL) were performed by the way of half-wave-rectified current (HWRC) for an evaluation of the PCL system in the drive with the large-rippled current. The current ripple of the HWRC is large, and we discussed the cooling capability of the current ripple. The experimental results revealed that the temperature difference of the thermoelectric-element (TE) increased with the magnitude of the current in the PCL system, despite the large current ripple. Calorimetric measurements revealed that the PCL reduced the heat leak of 60% for the peak current 90A. We compared the PCL systems of the direct current (dc) mode and the HWRC mode. The results showed that the current dependence of the temperature difference in the HWRC mode did not match that of the dc mode, but those of the heat leak matched well. The performance of the Peltier cooling in the HWRC mode is reduced to be 2/pi time of the Seebeck coefficient for the dc mode by using the time-average method. (author)

  12. Evaluation of the Acceleration and Deceleration Phase-Rectified Slope to Detect and Improve IUGR Clinical Management

    Directory of Open Access Journals (Sweden)

    Salvatore Tagliaferri

    2015-01-01

    Full Text Available Objective. This study used a new method called Acceleration (or Deceleration Phase-Rectified Slope, APRS (or DPRS to analyze computerized Cardiotocographic (cCTG traces in intrauterine growth restriction (IUGR, in order to calculate acceleration- and deceleration-related fluctuations of the fetal heart rate, and to enhance the prediction of neonatal outcome. Method. Cardiotocograms from a population of 59 healthy and 61 IUGR fetuses from the 30th gestation week matched for gestational age were included. APRS and DPRS analysis was compared to the standard linear and nonlinear cCTG parameters. Statistical analysis was performed through the t-test, ANOVA test, Pearson correlation test and receiver operator characteristic (ROC curves (p<0,05. Results. APRS and DPRS showed high performance to discriminate between Healthy and IUGR fetuses, according to gestational week. A linear correlation with the fetal pH at birth was found in IUGR. The area under the ROC curve was 0.865 for APRS and 0.900 for DPRS before the 34th gestation week. Conclusions. APRS and DPRS could be useful in the identification and management of IUGR fetuses and in the prediction of the neonatal outcome, especially before the 34th week of gestation.

  13. Livermore blasted for project delay

    CERN Multimedia

    1999-01-01

    In a 12 page report issued last week, a review committee set up by the University of California has concluded that mismanagement and poor planning are to blame for significant cost overruns and delays in the construction of NIF, the worlds largest laser (1 page).

  14. EAMJ Delayed April 10.indd

    African Journals Online (AJOL)

    2010-04-04

    Apr 4, 2010 ... Patient delay accounts for a large proportion of those who present with late stage disease especially ... Data collection: All patients diagnosed with breast cancer who certified the inclusion criteria were ..... Ingram, D.M., Huang, H.Y., Catchpole, B.N. and. Roberts, A. Do big breasts disadvantage women with.

  15. Diagnostic Delay in Rheumatoid Arthritis

    DEFF Research Database (Denmark)

    Mølbaek, Karen; Hørslev-Petersen, Kim; Primdahl, Jette

    2016-01-01

    BACKGROUND: To prevent joint damage among patients with rheumatoid arthritis (RA), there is a need to minimize delays from the onset of symptoms until the initiation of appropriate therapy. The present study explored the factors that have an impact on the time it takes for Danish patients with RA...

  16. Design flaw could delay collider

    CERN Multimedia

    Cho, Adrian

    2007-01-01

    "A magnet for the Large Hadron Collider (LHC) failed during a key test at the European particle physics laboratory CERN last week. Physicists and engineers will have to repair the damaged magnet and retrofit others to correct the underlynig design flaw, which could delay the start-up of the mammouth subterranean machine." (1,5 page)

  17. Delayed logistic population models revisited

    OpenAIRE

    Liz, Eduardo

    2014-01-01

    We discuss the global dynamics of some logistic models governed by delay-differential equations. We focus on models of exploited populations, and study the changes in the dynamics as the harvesting effort is increased. We get new results and highlight the link among different logistic equations usually employed in population models.

  18. Providing delay guarantees in Bluetooth

    NARCIS (Netherlands)

    Ait Yaiz, R.; Heijenk, Geert; Titsworth, F.

    2003-01-01

    Bluetooth polling, also referred to as Bluetooth MAC scheduling or intra-piconet scheduling, is the mechanism that schedules the traffic between the participants in a Bluetooth network. Hence, this mechanism is highly determining with respect to the delay packets experience in a Bluetooth network.

  19. Tooth formation - delayed or absent

    Science.gov (United States)

    ... tooth formation; Teeth - delayed or absent formation Images Tooth anatomy Development of baby teeth Development of permanent teeth References ... MO: Elsevier Mosby; 2016:chap 19. Tinanoff N. Development and developmental anomalies of the teeth. In: Kliegman RM, ... NIH MedlinePlus Magazine Read more ...

  20. Early-delayed radiation rhombencephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Nightingale, S.; Dawes, P.J.D.K.; Cartlidge, N.E.F. (Royal Victoria Infirmary, Newcastle upon Tyne (UK); Newcastle upon Tyne Univ. (UK). Newcastle General Hospital)

    1982-03-01

    A 37-year-old woman developed an early-delayed rhombencephalopathy 7 weeks after completing a course of radiotherapy to a glomus jugulare tumour. The clinical features, comprising nystagmus, skew strabismus, unilateral facial weakness, dysarthria and ataxia, are compared with four previously reported patients with this syndrome.

  1. Deconstructing delayed posttraumatic stress disorder

    NARCIS (Netherlands)

    Smid, G

    2011-01-01

    According to the Diagnostic and Statistical Manual of Mental Disorders, delayed posttraumatic stress disorder (PTSD) must be diagnosed in individuals fulfilling criteria for PTSD if the onset of symptoms is at least six months after the trauma. The purpose of this thesis was to establish the

  2. Fundamentals of Delayed Coking Joint Industry Project

    Energy Technology Data Exchange (ETDEWEB)

    Michael Volk Jr; Keith Wisecarver

    2005-10-01

    Delayed coking evolved steadily over the early to mid 1900s to enable refiners to convert high boiling, residual petroleum fractions to light products such as gasoline. Pound for pound, coking is the most energy intensive of any operation in a modern refinery. Large amounts of energy are required to heat the thick, poor-quality petroleum residuum to the 900 to 950 degrees F required to crack the heavy hydrocarbon molecules into lighter, more valuable products. One common misconception of delayed coking is that the product coke is a disadvantage. Although coke is a low valued (near zero economic value) byproduct, compared to transportation fuels, there is a significant worldwide trade and demand for coke as it is an economical fuel. Coke production has increased steadily over the last ten years, with further increases forecast for the foreseeable future. Current domestic production is near 111,000 tons per day. A major driving force behind this increase is the steady decline in crude quality available to refiners. Crude slates are expected to grow heavier with higher sulfur contents while environmental restrictions are expected to significantly reduce the demand for high-sulfur residual fuel oil. Light sweet crudes will continue to be available and in even greater demand than they are today. Refiners will be faced with the choice of purchasing light sweet crudes at a premium price, or adding bottom of the barrel upgrading capability, through additional new investments, to reduce the production of high-sulfur residual fuel oil and increase the production of low-sulfur distillate fuels. A second disadvantage is that liquid products from cokers frequently are unstable, i.e., they rapidly form gum and sediments. Because of intermediate investment and operating costs, delayed coking has increased in popularity among refiners worldwide. Based on the 2000 Worldwide Refining Survey published in the Oil and Gas, the delayed coking capacity for 101 refineries around the world

  3. A single MO-CFTA based electronically/temperature insensitive current-mode half-wave and full-wave rectifiers

    OpenAIRE

    Weerapon Kongnun; Phamorn Silapan

    2013-01-01

    The article presents a current-mode full-wave rectifier employing multiple output current follower transconductance amplifier (MO-CFTA). The both circuits description is very simple, it merely comprises only single MO-CFTA, without external passive element. In addition, the magnitude and direction of output currents can be controlled via electronically method. Furthermore, the outputs are independent of the thermal voltage (VT). The performances of the proposed circuits are investigated thro...

  4. Crystal Structure of the Eukaryotic Strong Inward-Rectifier K[superscript +] Channel Kir2.2 at 3.1 Å Resolution

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Xiao; Avalos, Jose L.; Chen, Jiayun; MacKinnon, Roderick; (Rockefeller)

    2010-03-29

    Inward-rectifier potassium (K{sup +}) channels conduct K{sup +} ions most efficiently in one direction, into the cell. Kir2 channels control the resting membrane voltage in many electrically excitable cells, and heritable mutations cause periodic paralysis and cardiac arrhythmia. We present the crystal structure of Kir2.2 from chicken, which, excluding the unstructured amino and carboxyl termini, is 90% identical to human Kir2.2. Crystals containing rubidium (Rb{sup +}), strontium (Sr{sup 2+}), and europium (Eu{sup 3+}) reveal binding sites along the ion conduction pathway that are both conductive and inhibitory. The sites correlate with extensive electrophysiological data and provide a structural basis for understanding rectification. The channel's extracellular surface, with large structured turrets and an unusual selectivity filter entryway, might explain the relative insensitivity of eukaryotic inward rectifiers to toxins. These same surface features also suggest a possible approach to the development of inhibitory agents specific to each member of the inward-rectifier K{sup +} channel family.

  5. Reconfigurable Resonant Regulating Rectifier With Primary Equalization for Extended Coupling- and Loading-Range in Bio-Implant Wireless Power Transfer.

    Science.gov (United States)

    Li, Xing; Meng, Xiaodong; Tsui, Chi-Ying; Ki, Wing-Hung

    2015-12-01

    Wireless power transfer using reconfigurable resonant regulating (R(3)) rectification suffers from limited range in accommodating varying coupling and loading conditions. A primary-assisted regulation principle is proposed to mitigate these limitations, of which the amplitude of the rectifier input voltage on the secondary side is regulated by accordingly adjusting the voltage amplitude Veq on the primary side. A novel current-sensing method and calibration scheme track Veq on the primary side. A ramp generator simultaneously provides three clock signals for different modules. Both the primary equalizer and the R(3) rectifier are implemented as custom integrated circuits fabricated in a 0.35 μm CMOS process, with the global control implemented in FPGA. Measurements show that with the primary equalizer, the workable coupling and loading ranges are extended by 250% at 120 mW load and 300% at 1.2 cm coil distance compared to the same system without the primary equalizer. A maximum rectifier efficiency of 92.5% and a total system efficiency of 62.4% are demonstrated.

  6. Ohmic-rectifying conversion of Ni contacts on ZnO and the possible determination of ZnO thin film surface polarity.

    Directory of Open Access Journals (Sweden)

    Kim Guan Saw

    Full Text Available The current-voltage characteristics of Ni contacts with the surfaces of ZnO thin films as well as single crystal (0001 ZnO substrate are investigated. The ZnO thin film shows a conversion from Ohmic to rectifying behavior when annealed at 800°C. Similar findings are also found on the Zn-polar surface of (0001 ZnO. The O-polar surface, however, only shows Ohmic behavior before and after annealing. The rectifying behavior observed on the Zn-polar and ZnO thin film surfaces is associated with the formation of nickel zinc oxide (Ni1-xZnxO, where x = 0.1, 0.2. The current-voltage characteristics suggest that a p-n junction is formed by Ni1-xZnxO (which is believed to be p-type and ZnO (which is intrinsically n-type. The rectifying behavior for the ZnO thin film as a result of annealing suggests that its surface is Zn-terminated. Current-voltage measurements could possibly be used to determine the surface polarity of ZnO thin films.

  7. Risks and Benefits of Rapid Clozapine Titration.

    Science.gov (United States)

    Lochhead, Jeannie D; Nelson, Michele A; Schneider, Alan L

    2016-05-18

    Clozapine is often considered the gold standard for the treatment of schizophrenia. Clinical guidelines suggest a gradual titration over 2 weeks to reduce the risks of adverse events such as seizures, hypotension, agranulocytosis, and myocarditis. The slow titration often delays time to therapeutic response. This raises the question of whether, in some patients, it may be safe to use a more rapid clozapine titration. The following case illustrates the potential risks associated with the use of multiple antipsychotics and rapid clozapine titration. We present the case of a young man with schizophrenia who developed life threatening neuroleptic malignant syndrome (NMS) during rapid clozapine titration and treatment with multiple antipsychotics. We were unable to find another case in the literature of NMS associated with rapid clozapine titration. This case is meant to urge clinicians to carefully evaluate the risks and benefits of rapid clozapine titration, and to encourage researchers to further evaluate the safety of rapid clozapine titration. Rapid clozapine titration has implications for decreasing health care costs associated with prolonged hospitalizations, and decreasing the emotional suffering associated with uncontrolled symptoms of psychosis. Clozapine is considered the most effective antipsychotic available thus efforts should focus on developing strategies that would allow for safest and most efficient use of clozapine to encourage its utilization for treatment resistance schizophrenia.

  8. Risks and benefits of rapid clozapine titration

    Directory of Open Access Journals (Sweden)

    Jeannie D. Lochhead

    2016-05-01

    Full Text Available Clozapine is often considered the gold standard for the treatment of schizophrenia. Clinical guidelines suggest a gradual titration over 2 weeks to reduce the risks of adverse events such as seizures, hypotension, agranulocytosis, and myocarditis. The slow titration often delays time to therapeutic response. This raises the question of whether, in some patients, it may be safe to use a more rapid clozapine titration. The following case illustrates the potential risks associated with the use of multiple antipsychotics and rapid clozapine titration. We present the case of a young man with schizophrenia who developed life threatening neuroleptic malignant syndrome (NMS during rapid clozapine titration and treatment with multiple antipsychotics. We were unable to find another case in the literature of NMS associated with rapid clozapine titration. This case is meant to urge clinicians to carefully evaluate the risks and benefits of rapid clozapine titration, and to encourage researchers to further evaluate the safety of rapid clozapine titration. Rapid clozapine titration has implications for decreasing health care costs associated with prolonged hospitalizations, and decreasing the emotional suffering associated with uncontrolled symptoms of psychosis. Clozapine is considered the most effective antipsychotic available thus efforts should focus on developing strategies that would allow for safest and most efficient use of clozapine to encourage its utilization for treatment resistance schizophrenia.

  9. Delay of Vehicle Motion in Traffic Dynamics

    CERN Document Server

    Bando, M; Nakanishi, K; Nakayama, A; Bando, Masako; Hasebe, Katsuya; Nakanishi, Ken; Nakayama, Akihiro

    1996-01-01

    We demonstrate that in Optimal Velocity Model (OVM) delay times of vehicles coming from the dynamical equation of motion of OVM almost explain the order of delay times observed in actual traffic flows without introducing explicit delay times. Delay times in various cases are estimated: the case of a leader vehicle and its follower, a queue of vehicles controlled by traffic lights and many-vehicle case of highway traffic flow. The remarkable result is that in most of the situation for which we can make a reasonable definition of a delay time, the obtained delay time is of order 1 second.

  10. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-01-08

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  11. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-11-09

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  12. Air congestion delay: a review

    Directory of Open Access Journals (Sweden)

    Daniel Alberto Pamplona

    2016-04-01

    Full Text Available This article is a literature review of the air congestion delay and its costs. Air congestion is a worldwide problem. Its existence brings costs for airlines and discomfort for passengers. With the increasing demand for air transport, the study of air congestion has attracted the attention of many researchers around the world. The cause for the delays is erroneously attributed only to the lack of infrastructure investments. The literature review shows that other factors such as population growth, increasing standards of living, lack of operational planning and environmental issues exercise decisive influence. Several studies have been conducted in order to analyze and propose solutions to this problem that affects society as a whole.

  13. Assembly delay line pulse generators

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    Assembly of six of the ten delay line pulse generators that will power the ten kicker magnet modules. One modulator part contains two pulse generators. Capacitors, inductances, and voltage dividers are in the oil tank on the left. Triggered high-pressure spark gap switches are on the platforms on the right. High voltage pulse cables to the kicker magnet emerge under the spark gaps. In the centre background are the assembled master gaps.

  14. ATLAS calibration delay chip study

    CERN Document Server

    Massol, N

    2003-01-01

    The delay chip is an ASIC developed to precisely adjust signals within the range of 0-24ns in steps of 1ns. In this note, we report the study of the characteristics of this chip like the linearity and the jitter. We describe the influence of temperature and supply voltage on its behavior. Finally, we study its dependency due to the variations in process on a whole production.

  15. Teriparatide Induced Delayed Persistent Hypercalcemia

    Directory of Open Access Journals (Sweden)

    Nirosshan Thiruchelvam

    2014-01-01

    Full Text Available Teriparatide, a recombinant PTH, is an anabolic treatment for osteoporosis that increases bone density. Transient hypercalcemia is a reported side effect of teriparatide that is seen few hours following administration of teriparatide and resolves usually within 16 hours of drug administration. Persistent hypercalcemia, although not observed in clinical trials, is rarely reported. The current case describes a rare complication of teriparatide induced delayed persistent hypercalcemia.

  16. Phase-rectified signal averaging for intrapartum electronic fetal heart rate monitoring is related to acidaemia at birth.

    Science.gov (United States)

    Georgieva, A; Papageorghiou, A T; Payne, S J; Moulden, M; Redman, C W G

    2014-06-01

    Recent studies suggest that phase-rectified signal averaging (PRSA), measured in antepartum fetal heart rate (FHR) traces, may sensitively indicate fetal status; however, its value has not been assessed during labour. We determined whether PRSA relates to acidaemia in labour, and compare its performance to short-term variation (STV), a related computerised FHR feature. Historical cohort. Large UK teaching hospital. All 7568 Oxford deliveries that met the study criteria from April 1993 to February 2008. We analysed the last 30 minutes of the FHR and associated outcomes of infants. We used computerised analysis to calculate PRSA decelerative capacity (DC(PRSA)), and its ability to predict umbilical arterial blood pH ≤ 7.05 using receiver operator characteristic (ROC) curves and event rate estimates (EveREst). We compared DC(PRSA) with STV calculated on the same traces. Umbilical arterial blood pH ≤ 7.05. We found that PRSA could be measured in all cases. DC(PRSA) predicted acidaemia significantly better than STV: the area under the ROC curve was 0.665 (95% CI 0.632-0.699) for DC(PRSA), and 0.606 (0.573-0.639) for STV (P = 0.007). EveREst plots showed that in the worst fifth centile of cases, the incidence of low pH was 17.75% for DC(PRSA) but 11.00% for STV (P < 0.001). DC(PRSA) was not highly correlated with STV. DC(PRSA) of the FHR can be measured in labour, and appears to predict acidaemia more accurately than STV. Further prospective evaluation is warranted to assess whether this could be clinically useful. The weak correlation between DC(PRSA) and STV suggests that they could be combined in multivariate FHR analyses. © 2014 Royal College of Obstetricians and Gynaecologists.

  17. Projection of Stabilized Aerial Imagery Onto Digital Elevation Maps for Geo-Rectified and Jitter-Free Viewing

    Science.gov (United States)

    Ansar, Adnan I.; Brennan, Shane; Clouse, Daniel S.

    2012-01-01

    As imagery is collected from an airborne platform, an individual viewing the images wants to know from where on the Earth the images were collected. To do this, some information about the camera needs to be known, such as its position and orientation relative to the Earth. This can be provided by common inertial navigation systems (INS). Once the location of the camera is known, it is useful to project an image onto some representation of the Earth. Due to the non-smooth terrain of the Earth (mountains, valleys, etc.), this projection is highly non-linear. Thus, to ensure accurate projection, one needs to project onto a digital elevation map (DEM). This allows one to view the images overlaid onto a representation of the Earth. A code has been developed that takes an image, a model of the camera used to acquire that image, the pose of the camera during acquisition (as provided by an INS), and a DEM, and outputs an image that has been geo-rectified. The world coordinate of the bounds of the image are provided for viewing purposes. The code finds a mapping from points on the ground (DEM) to pixels in the image. By performing this process for all points on the ground, one can "paint" the ground with the image, effectively performing a projection of the image onto the ground. In order to make this process efficient, a method was developed for finding a region of interest (ROI) on the ground to where the image will project. This code is useful in any scenario involving an aerial imaging platform that moves and rotates over time. Many other applications are possible in processing aerial and satellite imagery.

  18. Analysis of longer period variation of the Kuroshio Current intrusion into the Luzon Strait using rectified wavelet power spectra

    Science.gov (United States)

    Yuan, Yaochu; Yang, Chenghao; Tseng, Yu-heng; Zhu, Xiao-Hua; Wang, Huiqun; Chen, Hong

    2017-08-01

    Longer period variation of the Kuroshio into the Luzon Strait (LS) was identified using acoustic Doppler current profiler (ADCP) observations as well as pressure and temperature time series data recorded by two TDs (manufactured by the RBR Ltd.) at mooring station N2 (20°40.441‧N, 120°38.324‧E). The ADCP was deployed at depths of 50-300 m between July 7, 2009 and April 10, 2011, and the TDs at around 340 and 365 m between July 9, 2009 and July 9, 2011. Observations provide strong evidence of longer period variation of the Kuroshio into the LS using the Vector rotary spectra (VRS) and Rectified wavelet power spectra analysis (RWPSA). RWPSA of the observations allowed the identification of two types of dominant periods. The first type, with the strongest power spectral density (PSD), had a dominant period of 112 d and was found throughout the upper 300 m. For example, the maximum PSD for western and northern velocity components time series were 3800 and 3550 at 50 m, respectively. The maximum power spectral density decrease with deeper depths, i.e., the depth dependence of maximum PSD. The 112 d period was also identified in the pressure and temperature time series data, at 340 m and 365 m. Combined RWPSA with VRS and mechanism analysis, it is clear that the occurrence of the most dominant period of 112 d in the upper 300 m is related to the clockwise meandering of the Kuroshio into the LS, which is caused by westward propagating stronger anticyclonic eddies from the interior ocean due to the interaction of Rossby eddies with the Kuroshio. The second type of dominant period, for example a 40 d period, is related to the anticlockwise meandering of the Kuroshio. The final dominant period of 14 d coincides with the fortnightly spring-neap tidal period.

  19. Cholesterol up-regulates neuronal G protein-gated inwardly rectifying potassium (GIRK) channel activity in the hippocampus.

    Science.gov (United States)

    Bukiya, Anna N; Durdagi, Serdar; Noskov, Sergei; Rosenhouse-Dantsker, Avia

    2017-04-14

    Hypercholesterolemia is a well known risk factor for the development of neurodegenerative disease. However, the underlying mechanisms are mostly unknown. In recent years, it has become increasingly evident that cholesterol-driven effects on physiology and pathophysiology derive from its ability to alter the function of a variety of membrane proteins including ion channels. Yet, the effect of cholesterol on G protein-gated inwardly rectifying potassium (GIRK) channels expressed in the brain is unknown. GIRK channels mediate the actions of inhibitory brain neurotransmitters. As a result, loss of GIRK function can enhance neuron excitability, whereas gain of GIRK function can reduce neuronal activity. Here we show that in rats on a high-cholesterol diet, cholesterol levels in hippocampal neurons are increased. We also demonstrate that cholesterol plays a critical role in modulating neuronal GIRK currents. Specifically, cholesterol enrichment of rat hippocampal neurons resulted in enhanced channel activity. In accordance, elevated currents upon cholesterol enrichment were also observed in Xenopus oocytes expressing GIRK2 channels, the primary GIRK subunit expressed in the brain. Furthermore, using planar lipid bilayers, we show that although cholesterol did not affect the unitary conductance of GIRK2, it significantly enhanced the frequency of channel openings. Last, combining computational and functional approaches, we identified two putative cholesterol-binding sites in the transmembrane domain of GIRK2. These findings establish that cholesterol plays a critical role in modulating GIRK activity in the brain. Because up-regulation of GIRK function can reduce neuronal activity, our findings may lead to novel approaches for prevention and therapy of cholesterol-driven neurodegenerative disease. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Inhibition of vascular smooth muscle inward-rectifier K(+) channels restores myogenic tone in mouse urinary bladder arterioles.

    Science.gov (United States)

    Tykocki, Nathan R; Bonev, Adrian D; Longden, Thomas A; Heppner, Thomas J; Nelson, Mark T

    2017-05-01

    Prolonged decreases in urinary bladder blood flow are linked to overactive and underactive bladder pathologies. However, the mechanisms regulating bladder vascular reactivity are largely unknown. To investigate these mechanisms, we examined myogenic and vasoactive properties of mouse bladder feed arterioles (BFAs). Unlike similar-sized arterioles from other vascular beds, BFAs failed to constrict in response to increases in intraluminal pressure (5-80 mmHg). Consistent with this lack of myogenic tone, arteriolar smooth muscle cell membrane potential was hyperpolarized (-72.8 ± 1.4 mV) at 20 mmHg and unaffected by increasing pressure to 80 mmHg (-74.3 ± 2.2 mV). In contrast, BFAs constricted to the thromboxane analog U-46619 (100 nM), the adrenergic agonist phenylephrine (10 µM), and KCl (60 mM). Inhibition of nitric oxide synthase or intermediate- and small-conductance Ca(2+)-activated K(+) channels did not alter arteriolar diameter, indicating that the dilated state of BFAs is not attributable to overactive endothelium-dependent dilatory influences. Myocytes isolated from BFAs exhibited BaCl2 (100 µM)-sensitive K(+) currents consistent with strong inward-rectifier K(+) (KIR) channels. Notably, block of these KIR channels "restored" pressure-induced constriction and membrane depolarization. This suggests that these channels, in part, account for hyperpolarization and associated absence of tone in BFAs. Furthermore, smooth muscle-specific knockout of KIR2.1 caused significant myogenic tone to develop at physiological pressures. This suggests that 1) the regulation of vascular tone in the bladder is independent of pressure, insofar as pressure-induced depolarizing conductances cannot overcome KIR2.1-mediated hyperpolarization; and 2) maintenance of bladder blood flow during bladder filling is likely controlled by neurohumoral influences. Copyright © 2017 the American Physiological Society.

  1. A nonsense mutation in the inward rectifier potassium channel gene, Kir6.2, is associated with familial hyperinsulinism.

    Science.gov (United States)

    Nestorowicz, A; Inagaki, N; Gonoi, T; Schoor, K P; Wilson, B A; Glaser, B; Landau, H; Stanley, C A; Thornton, P S; Seino, S; Permutt, M A

    1997-11-01

    ATP-sensitive potassium (K[ATP]) channels are an essential component of glucose-dependent insulin secretion in pancreatic islet beta-cells. These channels comprise the sulfonylurea receptor (SUR1) and Kir6.2, a member of the inward rectifier K+ channel family. Mutations in the SUR1 subunit are associated with familial hyperinsulinism (HI) (MIM:256450), an inherited disorder characterized by hyperinsulinism in the neonate. Since the Kir6.2 gene maps to human chromosome 11p15.1 (1,2), which also encompasses a locus for HI, we screened the Kir6.2 gene for the presence of mutations in 78 HI probands by single-strand conformation polymorphism (SSCP) and nucleotide sequence analyses. A nonsense mutation, Tyr-->Stop at codon 12 (designated Y12X) was observed in the homozygous state in a single proband. 86Rb+ efflux measurements and single-channel recordings of COS-1 cells co-expressing SUR1 and either wild-type or Y12X mutant Kir6.2 proteins confirmed that K(ATP) channel activity was abolished by this nonsense mutation. The identification of an HI patient homozygous for the Kir6.2/Y12X allele affords an opportunity to observe clinical features associated with mutations resulting in an absence of Kir6.2. These data provide evidence that mutations in the Kir6.2 subunit of the islet beta-cell K(ATP) channel are associated with the HI phenotype and also suggest that the majority of HI cases are not attributable to mutations in the coding region of the Kir6.2 gene.

  2. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-05-14

    This thesis presents a general framework and method for detection of an object in a video based on apparent motion. The object moves, at some unknown time, differently than the “background” motion, which can be induced from camera motion. The goal of proposed method is to detect and segment the object as soon it moves in an online manner. Since motion estimation can be unreliable between frames, more than two frames are needed to reliably detect the object. Observing more frames before declaring a detection may lead to a more accurate detection and segmentation, since more motion may be observed leading to a stronger motion cue. However, this leads to greater delay. The proposed method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms, defined as declarations of detection before the object moves or incorrect or inaccurate segmentation at the detection time. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  3. Evaluating Ubiquitous Media Usability Challenges: Content Transfer and Channel Switching Delays

    DEFF Research Database (Denmark)

    Fleury, Alexandre; Pedersen, Jakob Schou; Larsen, Lars Bo

    2011-01-01

    As ubiquitous media is developing rapidly, new HCI challenges emerge. In this paper, we address usability issues related to the transfer of content between fixed and mobile devices, as well as channel switching delays on mobile devices. We first provide an extensive review of the field. We...... a threshold level above which people appear to be annoyed when switching between TV channels on a mobile device, and investigate factors that may influence the perceived acceptability of such delay....

  4. severe organophosphate poisoning with delayed cholinergic crisis

    African Journals Online (AJOL)

    Abrham

    2011-01-06

    Jan 6, 2011 ... CASE REPORT. SEVERE ORGANOPHOSPHATE POISONING WITH DELAYED. CHOLINERGIC CRISIS, INTERMEDIATE SYNDROME AND. ORGANOPHOSPHATE. INDUCED. DELAYED. POLYNEUROPATHY ON SUCCESSION. Aklilu Azazh. ABSTRACT. Organophosphate compounds are the organic ...

  5. Delay Margin in Controlling a Furuta Pendulum

    OpenAIRE

    Hernández-Díez, José-Enrique; Niculescu, Silviu-Iulian; Méndez-Barrios, César-Fernando; González-Galván, Emilio-Jorge; Loredo-Flores, Ambrocio; Escareno, Juan-Antonio

    2017-01-01

    International audience; This paper focuses on the design of an LQR based control scheme for the stabilization of the Furuta Pendulum in its unstable equilibrium point at the upright position. More precisely, we are interested in characterizing the corresponding delay margin under the assumption that the feedback loop includes time-delay. The paper provides an explicit tool to compute the critical delay value in the state feedback loop and a delicate tuning to reach larger delay values. In ord...

  6. A Developmental Study on Delay of Gratification

    OpenAIRE

    Kobayashi, Sayoko; Mitsumoto, Takashi

    2009-01-01

    Two studies were conducted to investigate development of delay of gratification. In Study 1, the personal delay of gratification test, social delay of gratification inventory and personality inventory were administered to kindergarteners aged 3 to 6 years. The personal delay of gratification test included three reward pairs and subjects were instructed to choose between a less valuable reward which was immediately available and a more valuable reward which was available tomorrow. In the perso...

  7. Cyclopentane combustion. Part II. Ignition delay measurements and mechanism validation

    KAUST Repository

    Rachidi, Mariam El

    2017-06-12

    This study reports cyclopentane ignition delay measurements over a wide range of conditions. The measurements were obtained using two shock tubes and a rapid compression machine, and were used to test a detailed low- and high-temperature mechanism of cyclopentane oxidation that was presented in part I of this study (Al Rashidi et al., 2017). The ignition delay times of cyclopentane/air mixtures were measured over the temperature range of 650–1350K at pressures of 20 and 40atm and equivalence ratios of 0.5, 1.0 and 2.0. The ignition delay times simulated using the detailed chemical kinetic model of cyclopentane oxidation show very good agreement with the experimental measurements, as well as with the cyclopentane ignition and flame speed data available in the literature. The agreement is significantly improved compared to previous models developed and investigated at higher temperatures. Reaction path and sensitivity analyses were performed to provide insights into the ignition-controlling chemistry at low, intermediate and high temperatures. The results obtained in this study confirm that cycloalkanes are less reactive than their non-cyclic counterparts. Moreover, cyclopentane, a high octane number and high octane sensitivity fuel, exhibits minimal low-temperature chemistry and is considerably less reactive than cyclohexane. This study presents the first experimental low-temperature ignition delay data of cyclopentane, a potential fuel-blending component of particular interest due to its desirable antiknock characteristics.

  8. Blood Transfusion Delay and Outcome in County Hospitals in Kenya.

    Science.gov (United States)

    Thomas, Julius; Ayieko, Philip; Ogero, Morris; Gachau, Susan; Makone, Boniface; Nyachiro, Wycliffe; Mbevi, George; Chepkirui, Mercy; Malla, Lucas; Oliwa, Jacquie; Irimu, Grace; English, Mike

    2017-02-08

    Severe anemia is a leading indication for blood transfusion and a major cause of hospital admission and mortality in African children. Failure to initiate blood transfusion rapidly enough contributes to anemia deaths in sub-Saharan Africa. This article examines delays in accessing blood and outcomes in transfused children in Kenyan hospitals. Children admitted with nonsurgical conditions in 10 Kenyan county hospitals participating in the Clinical Information Network who had blood transfusion ordered from September 2013 to March 2016 were studied. The delay in blood transfusion was calculated from the date when blood transfusion was prescribed to date of actual transfusion. Five percent (2,875/53,174) of admissions had blood transfusion ordered. Approximately half (45%, 1,295/2,875) of children who had blood transfusion ordered at admission had a documented hemoglobin transfusions, 82% were administered and documented in clinical records, and three-quarters of these (75%, 1,760/2,352) were given on the same day as ordered but these proportions varied from 71% to 100% across the 10 hospitals. Children who had a transfusion ordered but did not receive the prescribed transfusion had a mortality of 20%, compared with 12% among those transfused. Malaria-associated anemia remains the leading indication for blood transfusion in acute childhood illness admissions. Delays in transfusion are common and associated with poor outcomes. Variance in delay across hospitals may be a useful indicator of health system performance. © The American Society of Tropical Medicine and Hygiene.

  9. Hindrance of conservation biology by delays in the submission of manuscripts.

    Science.gov (United States)

    O'Donnell, Ryan P; Supp, Sarah R; Cobbold, Stephanie M

    2010-04-01

    Timely dissemination of scientific findings depends not only on rapid publication of submitted manuscripts, a topic which has received much discussion, but also on rapid submission of research after the research is completed. We measured submission delay (time from the last date of data collection to the submission of a manuscript) for every paper from 14 journals in 2007 and compared these submission delays among four fields of biology (conservation, taxonomy, behavior, and evolution). Manuscripts published in leading journals in the field of conservation biology have the longest delays in publication of accepted manuscripts and the longest intervals between completion of research and submission of the manuscript. Delay in manuscript submission accounts for more than half of the total time from last date of data collection to publication. Across fields, the number of authors was significantly negatively correlated with submission delay, but conservation journals had the second highest number of authors and the greatest submission delay, so submission of conservation manuscripts was not hindered by a shortage of collaboration relative to other fields. Rejection rates were greater in conservation journals than in behavior and evolution, but rejection times were faster; thus, there were no obvious net differences among fields in the time papers spent waiting to be rejected. Publication delay has been reduced significantly in the last 7 years, but was still greater in conservation journals than in any of the other three fields we studied. Thus, the urgent field of conservation biology is hindered in both preparation and publication of manuscripts.

  10. How long can fisheries management delay action in response to ecosystem and climate change?

    Science.gov (United States)

    Brown, Christopher J; Fulton, Elizabeth A; Possingham, Hugh P; Richardson, Anthony J

    2012-01-01

    Sustainable management of fisheries is often compromised by management delaying implementation of regulations that reduce harvest, in order to maintain higher catches in the short-term. Decreases or increases in fish population growth rate driven by environmental change, including ecosystem and climate change, affect the harvest that can be taken sustainably. If not acted on rapidly, environmental change could result in unsustainable fishing or missed opportunity for higher catches. Using simulation models of harvested fish populations influenced by environmental change, we explore how long fisheries managers can afford to wait before changing harvest regulations in response to changes in population growth. If environmental change causes population declines, delays greater than five years increase the probability of population collapse. Species with fast and highly variable population growth rates are more susceptible to collapse under delays and should be a priority for revised management where delays occur. Generally, the long-term cost of delay, in terms of lost fishing opportunity, exceeds the short-term benefits of overfishing. Lowering harvest limits and monitoring for environmental change can alleviate the impact of delays; however, these measures may be more costly than reducing delays. We recommend that management systems that allow rapid responses to population growth changes be enacted for fisheries management to adapt to ecosystem and climate change.

  11. Dynamic Cournot Duopoly Game with Delay

    Directory of Open Access Journals (Sweden)

    A. A. Elsadany

    2014-01-01

    Full Text Available The delay Cournot duopoly game is studied. Dynamical behaviors of the game are studied. Equilibrium points and their stability are studied. The results show that the delayed system has the same Nash equilibrium point and the delay can increase the local stability region.

  12. Synchronization analysis of coloured delayed networks under ...

    Indian Academy of Sciences (India)

    This paper investigates synchronization of coloured delayed networks under decentralized pinning intermittent control. To begin with, the time delays are taken into account in the coloured networks. In addition, we propose a decentralized pinning intermittent control for coloured delayed networks, which is different from that ...

  13. Academic Delay of Gratification and Academic Achievement

    Science.gov (United States)

    Bembenutty, Hefer

    2011-01-01

    The ability to delay gratification is the cornerstone of all academic achievement and education. It is by delaying gratification that learners can pursue long-term academic and career goals. In general, "delay of gratification" refers to an individual's ability to forgo immediate rewards for the sake of more valuable ones later (Mischel, 1996).…

  14. Delayed reinforcement and fixed-ratio performance.

    Science.gov (United States)

    Jarmolowicz, David P; Lattal, Kennon A

    2013-11-01

    Effects of delayed reinforcement on fixed-ratio (FR) maintained responding of pigeons were investigated. In Experiments 1-3, the delay of reinforcement was increased across successive sessions until pigeons paused for 300 s. Both signaled and unsignaled delays were studied across different conditions. Overall response rates and run rates (timed from the first to last response of a ratio) decreased and postreinforcement pauses increased as delays increased in each experiment. As delays increased, the likelihood of pausing during a ratio run also increased. When these measures were plotted as a function of obtained delays, signaled delays had less of an effect on the above measures than did unsignaled ones. In Experiment 2, delays had a greater effect on the above measures than did a control condition arranging equivalent interreinforcer intervals to those accompanying the delays. Experiments 3 and 4 examined the generality of the effects obtained in the first two experiments. In Experiment 3, delays imposed on FR or yoked-interval schedules had similar behavioral effects. In Experiment 4, effects similar to those found in Experiments 1-3 for 1, 10, and 20-s delays imposed on FR 50 schedules were found when the FR requirement increased across sessions. Despite the different contingencies relating response rate and reinforcement rates on interval and ratio schedules, delays of reinforcement generally affect performance on these schedules similarly. © Society for the Experimental Analysis of Behavior.

  15. User-centric video delay measurements

    NARCIS (Netherlands)

    A.J. Jansen (Jack); D.C.A. Bulterman (Dick)

    2013-01-01

    htmlabstractThe complexities and physical constraints associated with video transmission make the introduction of video playout delays unavoidable. Tuning systems to reduce delay requires an ability to effectively and easily gather delay metrics on a potentially wide range of systems. In order to

  16. Fatal deterioration of delayed acute subdural hematoma after mild traumatic brain injury: two cases with brief review

    Directory of Open Access Journals (Sweden)

    Chen Shiwen

    2014-04-01

    Full Text Available Both delayed posttraumatic intracerebral hemorrhage and epidural hematoma have been well described in the neurosurgical literatures. However, delayed posttraumatic acute subdural hematoma which happens more than a week with a rapid progress after mild traumatic brain injury and causes death of patient is rarely after mild traumatic brain injury: two cases with brief review reported. We show two such cases and briefly review the literature and discuss the probable pathogenesis of their rapid progress. Key words: Hematoma, subdural, acute; Brain injuries; Delayed diagnosis

  17. Delayed motor skill acquisition in kindergarten children with language impairment.

    Science.gov (United States)

    Adi-Japha, Esther; Strulovich-Schwartz, Orli; Julius, Mona

    2011-01-01

    The acquisition and consolidation of a new grapho-motor symbol into long-term memory was studied in 5-year-old children with language impairment (LI) and peers matched for age and visual-motor integration skills. The children practiced the production of a new symbol and were tested 24h and two weeks post-practice day. Differences in performance speed emerged between the groups: children with LI showed a later onset of rapid learning in the practice phase, and only the comparison group exhibited delayed, consolidation, gains 24h post-training. At two weeks post-training, children with LI improved, closing the gap in performance speed. Speed-accuracy trade-off was characteristic of speed improvements in LI. These results indicate atypical and delayed acquisition in children with LI, and support the view that deficient skill acquisition in LI goes beyond the language system. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Delay Variation Model with Two Service Queues

    Directory of Open Access Journals (Sweden)

    Filip Rezac

    2010-01-01

    Full Text Available Delay in VoIP technology is very unpleasant issue and therefore a voice packets prioritization must be ensured. To maintain the high call quality a maximum information delivery time from the sender to the recipient is set to 150 ms. This paper focuses on the design of a mathematical model of end-to-end delay of a VoIP connection, in particular on a delay variation. It describes all partial delay components and mechanisms, their generation, facilities and mathematical formulations. A new approach to the delay variation model is presented and its validation has been done by experimention.

  19. Controllability of Nonlinear Fractional Delay Dynamical Systems

    Science.gov (United States)

    Nirmala, R. Joice; Balachandran, K.; Rodríguez-Germa, L.; Trujillo, J. J.

    2016-02-01

    This paper is concerned with controllability of nonlinear fractional delay dynamical systems with delay in state variables. The solution representations of fractional delay differential equations have been established by using the Laplace transform technique and the Mittag-Leffler function. Necessary and sufficient conditions for the controllability criteria of linear fractional delay systems are established. Further sufficient condition for the controllability of nonlinear fractional delay dynamical system are obtained by using the fixed point argument. Examples and numerical simulation are presented to illustrate the results.

  20. Fuzzy delay model based fault simulator for crosstalk delay fault test ...

    Indian Academy of Sciences (India)

    The delays of a logic gates or interconnect are affected by various fabrication process parameters and however accurate the delay models are, it is very difficult to model the process uncertainties. In this paper, the fuzzy delay model is employed for test generation of crosstalk delay faults in asynchronous sequential circuits.