Time Domain Response of Electrical Ceramics Micro to Megaseconds

MRS Proceedings ◽

10.1557/proc-500-203 ◽

1997 ◽

Vol 500 ◽

Author(s):

F. A. Modine

Keyword(s):

Electrical Properties ◽

Power Law ◽

Time Domain ◽

Polarization Current ◽

Electrical Measurements ◽

Dispersive Transport ◽

Electron Traps ◽

Source Impedance ◽

Wide Range ◽

The Time Domain

ABSTRACTThe electrical properties of ceramics can be measured in either the time domain or in the frequency domain. But for electrically nonlinear ceramics such as varistors, time-domain measurements provide insights that are different and more relevant to material performance as well as being more physically incisive. This article focuses specifically on the electrical properties of ZnO varistors, but much of it is of relevance for other materials, in particular those materials with grain-boundary barriers and disordered ceramics or glasses. The interpretation of electrical measurements in the time domain is profoundly influenced by such practical matters as source impedance and waveform characteristics. Experimental results are presented for both high and low source impedance relative to that of a test varistor, and the difference in experimental difficulty and ease of interpretation is described. Time-domain measurements of capacitance and of the inductive response of varistors to large, fast electrical pulses are presented and their implications for varistor theory are given. Experimental evidence is given of short- and long-term memory in varistors. These memory phenomena are ascribed respectively to the life time of holes that become trapped in barriers and to polarization currents originating from deep electron traps. Polarization current measurements are presented for a wide range of time and temperature. The power-law time dependence and “universal” behavior of these currents is discussed. The exponent that describes the power law behavior is seen to change with temperature, and the change is interpreted as a double transition from diffusive to dispersive transport that originates with current from two different electron traps.

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Research on the Time-Domain Dielectric Response of Multiple Impulse Voltage Aging Oil-Film Dielectrics

Energies ◽

10.3390/en14071948 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1948

Author(s):

Chenmeng Zhang ◽

Kailin Zhao ◽

Shijun Xie ◽

Can Hu ◽

Yu Zhang ◽

...

Keyword(s):

Time Domain ◽

Dielectric Response ◽

Early Stage ◽

Debye Model ◽

Polarization Current ◽

Depolarization Current ◽

Oil Film ◽

Impulse Voltage ◽

The Time Domain ◽

Film Dielectric

Power capacitors suffer multiple impulse voltages during their lifetime. With the multiple impulse voltage aging, the internal insulation, oil-film dielectric may deteriorate and even fail in the early stage, which is called accumulative effect. Hence, the time-domain dielectric response of oil-film dielectric with multiple impulse voltage aging is studied in this paper. At first, the procedure of the preparation of the tested samples were introduced. Secondly, an aging platform, impulse voltage generator was built to test the accumulative effect of capacitor under multiple impulse voltage. Then, a device was used to test the time-domain dielectric response (polarization depolarization current, PDC) of oil-film dielectric in different aging states. And finally, according to the PDC data, extended Debye model and characteristic parameters were obtained by matrix pencil algorithm identification. The results indicated that with the increase of impulse voltage times, the time-domain dielectric response of oil-film dielectric changed accordingly. The polarization current curve moved up gradually, the insulation resistance decreased when subjected to the repeated impulses. In frequency domain, the frequency spectrum of tan δ changed along with the impulse accumulation aging, especially at low frequency. At last, combined with the aging mechanism of oil-film dielectric under multiple impulse voltage, the test results were discussed.

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Two optical emission components with different variability in V404 Cygni

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317000011 ◽

2016 ◽

Vol 12 (S324) ◽

pp. 43-44

Author(s):

Yutaro Tachibana ◽

Taketoshi Yoshii ◽

Nobuyuki Kawai

Keyword(s):

Spectral Index ◽

Power Law ◽

Time Domain ◽

Optical Emission ◽

Time Domain Analysis ◽

Blackbody Radiation ◽

Light Curves ◽

Variable Component ◽

Single Temperature ◽

The Time Domain

AbstractV404 Cygni went into an outburst again on June 15, 2015 after 26 years of quietness. Soon after the notifications, we started intense optical observation campaign of this source. The spectral index between RC and IC-band was stable over the outburst, whereas that between g′ and RC-band varied violently. With the time domain analysis of the multi-color optical light curves, we successfully decomposed optical variations into three components: highly-variable component (HVC), little-variable component (LVC). The loci of the LVC in the color-color diagram is consistent with that of a single temperature blackbody radiation or a multi-color blackbody radiation from a standard accretion disk, while those of the HVC trace that of power-law spectra.

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Electromagnetic modeling of 3-D sources over 2-D inhomogeneities in the time domain

Geophysics ◽

10.1190/1.1443325 ◽

1992 ◽

Vol 57 (8) ◽

pp. 994-1003 ◽

Cited By ~ 19

Author(s):

Michael Leppin

Keyword(s):

Differential Equations ◽

Diffusion Equation ◽

Time Domain ◽

Magnetic Induction ◽

Host Rock ◽

Vertical Component ◽

Wavenumber Domain ◽

Transient Electromagnetic ◽

Wide Range ◽

The Time Domain

A numerical method is presented by which the transient electromagnetic response of a two‐dimensional (2-D) conductor, embedded in a conductive host rock and excited by a rectangular current loop, can be modeled. This 2.5-D modeling problem has been formulated in the time domain in terms of a vector diffusion equation for the scattered magnetic induction, which is Fourier transformed into the spatial wavenumber domain in the strike direction of the conductor. To confine the region of solution of the diffusion equation to the conductive earth, boundary values for the components of the magnetic induction on the ground surface have been calculated by means of an integral transform of the vertical component of the magnetic induction at the air‐earth interface. The system of parabolic differential equations for the three magnetic components has been integrated for 9 to 15 discrete spatial wavenumbers ranging from [Formula: see text] to [Formula: see text] using an implicit homogeneous finite‐difference scheme. The discretization of the differential equations on a grid representing a cross‐section of the conductive earth results in a large, sparse system of linear equations, which is solved by the successive overrelaxation method. The three‐dimensional (3-D) response has been computed by an inverse Fourier transformation of the cubic spline interpolated scattered magnetic induction in the wavenumber domain using a digital filtering technique. To test the algorithm, responses have been computed for a two‐layered half‐space and a vertical prism embedded in a conductive host rock. These examples were then compared with results obtained analytically or numerically using frequency‐domain finite‐element and time‐domain integral equation methods. The new numerical procedure gives satisfactory results for a wide range of 2-D conductivity distributions with conductivity ratios exceeding 1:100, provided the grid is sufficiently refined at the corners of the conductivity anomalies.

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Innovative Multi-Site Photoplethysmography Analysis for Quantifying Pulse Amplitude and Timing Variability Characteristics in Peripheral Arterial Disease

10.20944/preprints201808.0206.v1 ◽

2018 ◽

Author(s):

Michael Bentham ◽

Gerard Stansby ◽

John Allen

Keyword(s):

Peripheral Arterial Disease ◽

Frequency Domain ◽

Time Domain ◽

Domain Analysis ◽

Arterial Disease ◽

Timing Variability ◽

Wide Range ◽

Healthy Control ◽

The Time Domain ◽

Peripheral Arterial

Photoplethysmography (PPG) is a simple-to-perform vascular optics measurement technique that can detect changes in blood volume in the microvascular tissue bed. Beat-to-beat analysis of the PPG waveform enables the study of the variability of pulse features such as amplitude and pulse arrival time (PAT), and when quantified in the time and frequency domains, has considerable potential to shed light on perfusion changes associated with peripheral arterial disease (PAD). In this pilot study innovative multi-site bilateral finger and toe PPG recordings from 43 healthy control subjects and 31 PAD subjects were compared (recordings each at least 5 minutes, collected in a warm temperature-controlled room). Beat-to-beat normalized amplitude and PAT variability was then quantified in the time-domain using SD and IQR measures and in the frequency-domain bilaterally using Magnitude Squared Coherence (MSC). Significantly reduced normalized amplitude variability (healthy control 0.0384 (IQR 0.0217-0.0744) vs PAD 0.0160 (0.0080-0.0338) (p<0.001) and significantly increased PAT variability (healthy control 0.0063 (0.0052-0.0086) vs PAD 0.0093 (0.0078-0.0144) (p<0.001) was demonstrated in PAD using the time-domain analysis. Frequency-domain analysis demonstrated significantly lower MSC values across a range of frequency bands for PAD patients. These changes suggest a loss of right-to-left body side coherence and cardiovascular control in PAD. This study has also demonstrated the feasibility of using these measurement and analysis methods in studies investigating multi-site PPG variability for a wide range of cardiac and vascular patient groups.

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Steady state signatures in the time domain for nonintrusive appliance identification

Ingeniería e Investigación ◽

10.15446/ing.investig.v35n1sup.53619 ◽

2015 ◽

Vol 35 (1Sup) ◽

pp. 58-64

Author(s):

Yulieth Jimenez ◽

Cesar Duarte ◽

Johann Petit ◽

Jan Meyer ◽

Peter Schegner ◽

...

Keyword(s):

Steady State ◽

Time Domain ◽

Energy Savings ◽

Single Point ◽

Impact Factors ◽

Font Size ◽

Electrical Measurements ◽

Stroke Width ◽

Load Monitoring ◽

The Time Domain

Smart Grid paradigm promotes advanced load monitoring applications to support demand side management and energy savings. Recently, considerable attention has been paid to Non-Intrusive Load Monitoring to estimate the individual operation and power consumption of the residential appliances, from single point electrical measurements. This approach takes advantage of signal processing in order to reduce the hardware effort associated to systems with multiple dedicated sensors. Discriminative characteristics of the appliances, namely load signatures, could be extracted from the transient or steady state electrical signals. In this paper the effect of impact factors that can affect the steady state load signatures under realistic conditions are investigated: the voltage supply distortion, the network impedance and the sampling frequency of the metering equipment. For this purpose, electrical measurements of several residential appliances were acquired and processed to obtain some indices in the time domain. Results include the comparison of distinct scenarios, and the evaluation of the suitability and discrimination capacity of the steady state information.<br style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" />

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Application of L1 Trend Filtering Technology on the Current Time Domain Spectroscopy of Dielectrics

Electronics ◽

10.3390/electronics8091046 ◽

2019 ◽

Vol 8 (9) ◽

pp. 1046

Author(s):

Changyou Suo ◽

Zhonghua Li ◽

Yunlong Sun ◽

Yongsen Han

Keyword(s):

Time Series ◽

Time Domain ◽

Time Complexity ◽

Time Range ◽

Test Results ◽

Current Time ◽

Time Domain Spectroscopy ◽

Filtering Algorithms ◽

Wide Range ◽

The Time Domain

The current time domain spectroscopy of dielectrics provides important information for the analysis of dielectric properties and mechanisms. However, there is always interference during the testing process, which seriously affects the analysis of the test results. Therefore, the effective filtering of current time domain spectroscopy is particularly necessary. L1 trend filtering can estimate the trend items exactly in a set of time series. It has been widely used in the fields of economics and sociology. Therefore, this paper attempts to apply L1 trend filtering to the current time domain spectroscopy. Firstly, polarization and depolarization currents are measured in the laboratory. Then the test results are filtered by L1 trend filtering and the filtering effects are compared with several common filtering algorithms, such as a sliding mean filter and Savitzky–Golay smoothing filter. Finally, the robustness and time complexity of L1 trend filtering are analyzed. The filtering results show that because the polarization currents vary in a wide range of the time domain (about 2–3 orders of magnitude), smooth and undistorted curves in the whole test time range can hardly be obtained through common filtering algorithms, while they can be obtained by L1 trend filtering. The results of robustness analysis and time complexity analysis show that L1 trend filtering can extract the trend items accurately in the time series under given different noise levels, and the execution time is also lower than 176.67 s when the number of tested points is no more than 20,000. Those results show that L1 trend filtering can be applied to the time domain current spectroscopy of dielectrics.

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The Effects of Source Impedance on the Time-Domain Performance of UWB Bowtie Antennas

2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) ◽

10.1109/piers-spring46901.2019.9017326 ◽

2019 ◽

Author(s):

X. Gao ◽

W. van Verre ◽

F. J. W. Podd ◽

D. J. Daniels ◽

A. J. Peyton

Keyword(s):

Time Domain ◽

Source Impedance ◽

The Time Domain ◽

Domain Performance

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Electrical Properties of Elastomers and Related Polymers

Rubber Chemistry and Technology ◽

10.5254/1.3539647 ◽

1963 ◽

Vol 36 (5) ◽

pp. 1230-1302 ◽

Cited By ~ 7

Author(s):

Archibald T. McPherson

Keyword(s):

Dielectric Constant ◽

Electrical Properties ◽

Price Competition ◽

Modern Technology ◽

Point Of View ◽

Electrical Behavior ◽

Electrical Measurements ◽

Wide Range ◽

The Individual ◽

High Dielectric

Abstract Interest in the electrical behavior of elastomers stems from several widely different sources. From the theoretical standpoint electrical measurements provide a valuable tool for the study of the molecular structure of elastomers and other polymers and the relation of structure to properties. From a practical point of view an understanding of the electrical behavior enables the manufacturer of wire and cable to produce insulation that will better withstand the severe conditions of space flight, or that will meet price competition and show a profit. The present day applications of elastomers are so many and varied that nearly any type of compound is likely to be employed for some practical purpose. A cable for x-ray equipment, for example, may be made wholly from elastomers with conductor, insulation, and jacket each from a different compound. At one time when almost the only electrical use of rubber was to provide the highest practical degree of electrical insulation it was correct to speak of “good” and “poor” electrical properties. Now, however, an elastomer that is a poor insulator may be excellent in an antistatic application. Communication cables require an insulation of the lowest practical dielectric constant, but for power cables a layer of insulation of high dielectric constant next to the conductor may be essential to prevent excessive electrical stresses. Modern technology not only calls for a wide diversity of electrical properties but it often requires further that elastomers having these properties be available in a wide range of mechanical properties. For example, the insulation on a cable for use in an airplane must be as thin and light as possible to save weight while an unarmored cable for laying in shallow water must have insulation that is thick and tough for mechanical protection and of high specific gravity to prevent the cable's being moved by waves or tide. Thus, the diversity of present and possible future applications is such that no one in the industry is likely to escape for long some contact with an application involving an electrical property. Accordingly, this review has been prepared to acquaint the rubber chemist and technologist with current information in the field. In the 25 years that have elapsed since an earlier review was prepared by the same author a great deal of work has been done on the relation between the properties of polymers and their molecular composition and structure. It is now possible to predict the properties of some polymers from their structural formulas, and a beginning has been made in relating the properties of simple elastomeric compounds to the properties of the different ingredients. However, knowledge in the field is still far from the state at which it would be possible to compile a table of functions such that the electrical properties of a multi-ingredient insulating compound could be computed from the properties of the individual ingredients.

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A Computationally Efficient Algorithm for Feedforward Active Noise Control Systems

Electronics ◽

10.3390/electronics9091504 ◽

2020 ◽

Vol 9 (9) ◽

pp. 1504 ◽

Cited By ~ 1

Author(s):

Stefano Gaiotto ◽

Antonino Laudani ◽

Gabriele Maria Lozito ◽

Francesco Riganti Fulginei

Keyword(s):

Frequency Domain ◽

Time Domain ◽

Noise Control ◽

Active Noise Control ◽

Parameter Tuning ◽

Processing Load ◽

Block Basis ◽

Active Noise ◽

Wide Range ◽

The Time Domain

In this paper, a novel algorithm with high computational efficiency is proposed for the filter adaptation in a feedforward active noise control system. The proposed algorithm Zero Forcing Block Adaptive Filter (ZF-BAF) performs filter adaptation on a block-by-block basis in the frequency domain. Filtering is performed in the time domain on a sample-by-sample basis. Working in the frequency domain permits us to get sub-linear complexity, whereas filtering in the time domain minimizes the latency. Furthermore, computational burden is tunable to meet specific requirements about adaptation speed and processing load. No other parameter tuning according to the working condition is required. Computer simulations, performed in different realistic cases against other high-performing time and frequency-domain algorithms, show that achievable performances are comparable, or even better, with those of the algorithms perfectly tuned for each specific case. Robustness exhibited in the tests suggests that performances are expected to be even better in a wide range of real cases where it is impossible to know a priori how to tune the algorithms.

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EVOLUTION OF ELECTROMAGNETIC AND DIRAC PERTURBATIONS AROUND A BLACK HOLE IN HOŘAVA GRAVITY

Modern Physics Letters A ◽

10.1142/s0217732311035936 ◽

2011 ◽

Vol 26 (22) ◽

pp. 1645-1656 ◽

Cited By ~ 7

Author(s):

NIJO VARGHESE ◽

V. C. KURIAKOSE

Keyword(s):

Black Hole ◽

Power Law ◽

Time Domain ◽

Quasinormal Modes ◽

Late Time ◽

Spacetime Geometry ◽

Field Evolution ◽

The Time Domain ◽

Integration Data ◽

Domain Integration

The evolution of electromagnetic and massless Dirac perturbations in the spacetime geometry of Kehagias–Sfetsos (KS) black hole in the deformed Hořava–Lifshitz (HL) gravity is investigated and the associated quasinormal modes (QNMs) are evaluated from time domain integration data. We find a considerable deviation in the nature of field evolution in HL theory from that in the Schwarzschild spacetime and QNM region extends over a longer time in HL theory before the power-law tail decay begins. The dependence of the field evolution on the HL parameter α is also studied. In the time domain picture we find that the length of QNM region increases with α. But the late-time decay of field follows the same power-law tail behavior as in the case of Schwarzschild black hole.

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