EFFECTS OF ELECTRODE RESISTANCE ON THE DIELECTRIC BEHAVIORS OF Au/BaxSr1−xTiO3/La1.1Sr0.9NiO4 CAPACITORS

BaxSr[Formula: see text]TiO3 ([Formula: see text]) (BST) thin films were prepared on La[Formula: see text]Sr[Formula: see text]NiO4 (LSNO)/SrTiO3 (STO) structure by combinatorial pulsed laser deposition (comb-PLD). The capacitances of the Au/BST/LSNO capacitors exhibited strong frequency dependence especially when the applied frequency was higher than 10[Formula: see text]kHz. On the basis of an equivalent circuit model, we presented a theoretical simulation of the relationships between capacitance and frequency for the capacitors with different electrode serial resistances. Based on the fitting results, the observed strong frequency dependence of the measured capacitance at high frequency in our study could be ascribed to the large serial resistance of 750 [Formula: see text] for oxide electrode LSNO. Further simulation studies found that large serial resistance (1000 [Formula: see text]) could result in an apparent deviation from the intrinsic dielectric properties especially at high frequencies ([Formula: see text]100[Formula: see text]kHz) for capacitors with capacitances above 1[Formula: see text]nF. Our results provide useful information for the design of all-oxide electronic devices.

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Optimal Damper Location for Mid-High Frequency Vibration Control on Built-Up Structures: Case Study Using VA One

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.105-107.705 ◽

2011 ◽

Vol 105-107 ◽

pp. 705-709

Author(s):

Asan G.A. Muthalif

Keyword(s):

High Frequency ◽

Energy Analysis ◽

Statistical Energy Analysis ◽

Simulation Studies ◽

The Finite Element Method ◽

Hybrid Modelling ◽

High Frequencies ◽

Modelling Method ◽

Good Agreement

This paper presents a guide to identify optimal damper location to reduce vibration on built-up structures. The guide is derived from simulation studies carried out on a set of benchmark models. Optimization is carried out using genetic algorithm. Optimal location is found using found using Generic algorithm and the hybrid method. The hybrid modelling method combines the finite element method (FEM) and Statistical energy analysis (SEA) to provide an efficient response predication for mid-high frequencies. The guide to find optimal damper location is tested on a fuselage model of Boeing 737. The fuselage model is developed using VA One software. Good agreement is seen for the optimal locations using the simple guide and result from VA One.

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A RF Redundant TSV Interconnection for High Resistance Si Interposer

Micromachines ◽

10.3390/mi12020169 ◽

2021 ◽

Vol 12 (2) ◽

pp. 169

Author(s):

Mengcheng Wang ◽

Shenglin Ma ◽

Yufeng Jin ◽

Wei Wang ◽

Jing Chen ◽

...

Keyword(s):

Millimeter Wave ◽

High Frequency ◽

High Performance ◽

Rapid Development ◽

Coplanar Waveguide ◽

Equivalent Circuit Model ◽

High Resistivity ◽

Performance Requirements ◽

Wave Radar ◽

Interconnect Design

Through Silicon Via (TSV) technology is capable meeting effective, compact, high density, high integration, and high-performance requirements. In high-frequency applications, with the rapid development of 5G and millimeter-wave radar, the TSV interposer will become a competitive choice for radio frequency system-in-package (RF SIP) substrates. This paper presents a redundant TSV interconnect design for high resistivity Si interposers for millimeter-wave applications. To verify its feasibility, a set of test structures capable of working at millimeter waves are designed, which are composed of three pieces of CPW (coplanar waveguide) lines connected by single TSV, dual redundant TSV, and quad redundant TSV interconnects. First, HFSS software is used for modeling and simulation, then, a modified equivalent circuit model is established to analysis the effect of the redundant TSVs on the high-frequency transmission performance to solidify the HFSS based simulation. At the same time, a failure simulation was carried out and results prove that redundant TSV can still work normally at 44 GHz frequency when failure occurs. Using the developed TSV process, the sample is then fabricated and tested. Using L-2L de-embedding method to extract S-parameters of the TSV interconnection. The insertion loss of dual and quad redundant TSVs are 0.19 dB and 0.46 dB at 40 GHz, respectively.

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Polymeric textile-based electromagnetic interference shielding materials, their synthesis, mechanism and applications – A review

Journal of Industrial Textiles ◽

10.1177/15280837211037085 ◽

2021 ◽

pp. 152808372110370

Author(s):

Faiza Safdar ◽

Munir Ashraf ◽

Amjed Javid ◽

Kashif Iqbal

Keyword(s):

Electromagnetic Interference ◽

Hybrid Composites ◽

Electronic Devices ◽

High Tech ◽

Emi Shielding ◽

Materials Synthesis ◽

Synthesis Mechanism ◽

High Frequencies ◽

Textile Materials ◽

Shielding Composites

The rapid proliferation of electronic devices and their operation at high frequencies has raised the contamination of artificial electromagnetic radiations in the atmosphere to an unprecedented level that is responsible for catastrophe for ecology and electronic devices. Therefore, the lightweight and flexible electromagnetic interference (EMI) shielding materials are of vital importance for controlling the pollution generated by such high-frequency EM radiations for protecting ecology and human health as well as the other nearby devices. In this regard, polymeric textile-based shielding composites have been proved to be the best due to their unique properties such as lightweight, excellent flexibility, low density, ease of processability and ease of handling. Moreover, such composites cover range of applications from everyday use to high-tech applications. Various polymeric textiles such as fibers, yarn, woven, nonwoven, knitted, as well as their hybrid composites have been extensively manipulated physically and/or chemically to act as shielding against such harmful radiations. This review encompasses from basic concept of EMI shielding for beginner to the latest research in polymeric-based textile materials synthesis for experts, covering detailed mechanisms with schematic illustration. The review also covers the gap of materials synthesis and their application on polymeric textiles which could be used for EMI shielding applications. Furthermore, recent research regarding rendering EMI shielding properties at various stages of polymeric textile development is provided for readers with critical analysis. Lastly, the applications along with environmental compliance have also been presented for better understanding.

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Rheology of rounded mammalian cells over continuous high-frequencies

Nature Communications ◽

10.1038/s41467-021-23158-0 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Gotthold Fläschner ◽

Cosmin I. Roman ◽

Nico Strohmeyer ◽

David Martinez-Martin ◽

Daniel J. Müller

Keyword(s):

High Frequency ◽

Mammalian Cells ◽

Mechanical Response ◽

Cell Mass ◽

Low Frequency ◽

Mass Measurements ◽

High Frequencies ◽

Polymer Relaxation ◽

Continuous Frequency ◽

Rheological Experiments

AbstractUnderstanding the viscoelastic properties of living cells and their relation to cell state and morphology remains challenging. Low-frequency mechanical perturbations have contributed considerably to the understanding, yet higher frequencies promise to elucidate the link between cellular and molecular properties, such as polymer relaxation and monomer reaction kinetics. Here, we introduce an assay, that uses an actuated microcantilever to confine a single, rounded cell on a second microcantilever, which measures the cell mechanical response across a continuous frequency range ≈ 1–40 kHz. Cell mass measurements and optical microscopy are co-implemented. The fast, high-frequency measurements are applied to rheologically monitor cellular stiffening. We find that the rheology of rounded HeLa cells obeys a cytoskeleton-dependent power-law, similar to spread cells. Cell size and viscoelasticity are uncorrelated, which contrasts an assumption based on the Laplace law. Together with the presented theory of mechanical de-embedding, our assay is generally applicable to other rheological experiments.

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Synchronous Machine Winding Modeling Method Based on Broadband Characteristics

Applied Sciences ◽

10.3390/app11104631 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4631

Author(s):

Yu Chen ◽

Xiaoqing Ji ◽

Zhongyong Zhao

Keyword(s):

Equivalent Circuit ◽

High Frequency ◽

Equivalent Circuit Model ◽

Black Box ◽

Synchronous Machine ◽

Circuit Model ◽

Modeling Method ◽

Experimental Results ◽

Box Model ◽

Impedance Curve

The accurate establishment of the equivalent circuit model of the synchronous machine windings’ broadband characteristics is the basis for the study of high-frequency machine problems, such as winding fault diagnosis and electromagnetic interference prediction. Therefore, this paper proposes a modeling method for synchronous machine winding based on broadband characteristics. Firstly, the single-phase high-frequency lumped parameter circuit model of synchronous machine winding is introduced, then the broadband characteristics of the port are analyzed by using the state space model, and then the equivalent circuit parameters are identified by using an optimization algorithm combined with the measured broadband impedance characteristics of port. Finally, experimental verification and comparison experiments are carried out on a 5-kW synchronous machine. The experimental results show that the proposed modeling method identifies the impedance curve of the circuit parameters with a high degree of agreement with the measured impedance curve, which indicates that the modeling method is feasible. In addition, the comparative experimental results show that, compared with the engineering exploratory calculation method, the proposed parameter identification method has stronger adaptability to the measured data and a certain robustness. Compared with the black box model, the parameters of the proposed model have a certain physical meaning, and the agreement with the actual impedance characteristic curve is higher than that of the black box model.

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EXTENSION OF THE FREQUENCY-RANGE OF INTERFEROMETERS FOR THE "MAGNETIC" COMPONENTS OF GRAVITATIONAL WAVES?

International Journal of Modern Physics A ◽

10.1142/s0217751x07036452 ◽

2007 ◽

Vol 22 (13) ◽

pp. 2361-2381 ◽

Cited By ~ 6

Author(s):

CHRISTIAN CORDA

Keyword(s):

Data Analysis ◽

Frequency Dependence ◽

Gravitational Waves ◽

Response Functions ◽

Frequency Range ◽

Total Response ◽

High Frequencies ◽

Magnetic Components ◽

Linear Dimensions ◽

Dominant Part

Recently, with an enlightening treatment, Baskaran and Grishchuk have shown the presence and importance of the so-called "magnetic" components of gravitational waves (GW's), which have to be taken into account in the context of the total response functions of interferometers for GW's propagating from arbitrary directions. In this paper the analysis of the response functions for the magnetic components is generalized in its full frequency dependence, while in the work of Baskaran and Grishchuk the response functions were computed only in the approximation of wavelength much larger than the linear dimensions of the interferometer. It is also shown that the response functions to the magnetic components grow at high frequencies, differently from the values of the response functions to the well-known ordinary components that decrease at high frequencies. Thus the magnetic components could in principle become the dominant part of the signal at high frequencies. This is important for a potential detection of the signal at high frequencies and confirms that the magnetic contributions must be taken into account in the data analysis. More, the fact that the response functions of the magnetic components grow at high frequencies shows that, in principle, the frequency-range of Earth-based interferometers could extend to frequencies over 10000 Hz.

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Electromagnetic Property of La0.7Sr0.3MnO3/Ag Composite at High Frequency

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.655.182 ◽

2015 ◽

Vol 655 ◽

pp. 182-185

Author(s):

Ke Lan Yan ◽

Run Hua Fan ◽

Min Chen ◽

Kai Sun ◽

Xu Ai Wang ◽

...

Keyword(s):

High Frequency ◽

Single Phase ◽

Low Frequency ◽

Electromagnetic Property ◽

High Frequency Range ◽

Frequency Range ◽

Free Electron Concentration ◽

Theoretical Simulation ◽

Electrical And Magnetic Properties ◽

Three Phase

The phase structure, and electrical and magnetic properties of La0.7Sr0.3MnO3(LSMO)-xAg (xis the mole ratio,x=0, 0.3, 0.5) composite were investigated. It is found that the sample withx=0 is single phase; the samples withx=0.3 and 0.5 present three phase composite structure of the manganese oxide and Ag. With the increasing of Ag content, the grain size of the samples increases and the grain boundaries transition from fully faceted to partially faceted. The permittivity of spectrum (10 MHz - 1 GHz) and the theoretical simulation reveal that the plasma frequencyfpincrease with Ag content, due to the increasing of free electron concentration, which is further supported by the enhancement of conductivity. While for the permeability (μr'), theμr'decrease with the increasing of Ag content at low frequency range (f< 20 MHz), while at the relative high frequency range (f> 300 MHz), theμr'increased with Ag content. Therefore, the introduction of elemental Ag resulted in a higherμr'at the relative high frequency range.

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Effect of mastoid drilling on hearing of the contralateral ear

The Journal of Laryngology & Otology ◽

10.1017/s0022215113001965 ◽

2013 ◽

Vol 127 (10) ◽

pp. 952-956 ◽

Cited By ~ 6

Author(s):

A Goyal ◽

P P Singh ◽

A Vashishth

Keyword(s):

Hearing Loss ◽

High Frequency ◽

Otoacoustic Emissions ◽

Pure Tone Audiometry ◽

Otoacoustic Emission ◽

Prospective Clinical Study ◽

Distortion Product Otoacoustic Emission ◽

High Frequencies ◽

Distortion Product ◽

Contralateral Ear

AbstractObjectives:This study aimed to: understand the effect that high intensity noise associated with drilling (during otological surgery) has on hearing in the contralateral ear; determine the nature of hearing loss, if any, by establishing whether it is temporary or persistent; and examine the association between hearing loss and various drill parameters.Methods:A prospective clinical study was carried out at a tertiary centre. Thirty patients with unilateral cholesteatoma and normal contralateral hearing were included. Patients were evaluated pre-operatively and for five days following surgery using high frequency pure tone audiometry, and low and high frequency transient evoked and distortion product otoacoustic emission testing.Results:The findings revealed statistically significant changes in distortion product otoacoustic emissions at high frequencies (p = 0.016), and in transient evoked otoacoustic emissions at both low and high frequencies (p = 0.035 and 0.021, respectively). There was a higher statistical association between otoacoustic emission changes and cutting burrs compared with diamond burrs.Conclusion:Drilling during mastoid surgery poses a threat to hearing in the contralateral ear due to noise and vibration conducted transcranially.

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