scholarly journals Frequency Dependent Electrical Properties of Ferroelectric Ba0.8Sr0.2TiO3 Thin Film

1970 ◽  
Vol 17 (2) ◽  
pp. 186-190 ◽  
Author(s):  
Ala’eddin A. SAIF ◽  
Zul Azhar ZAHID JAMAL ◽  
Zaliman SAULI ◽  
Prabakaran POOPALAN
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
High Frequency ◽  
Room Temperature ◽  
Electric Modulus ◽  
Low Frequency ◽  
Frequency Region ◽  
Electrical Parameters ◽  
High Frequency Region ◽  
Frequency Dependent

The frequency dependent electrical parameters, such as impedance, electric modulus, dielectric constant and AC conductivity for ferroelectric Ba0.8Sr0.2TiO3 thin film have been investigated within the range of 1 Hz and 106 Hz at room temperature. Z* plane shows two regions corresponding to the bulk mechanism and the distribution of the grain boundaries-electrodes process. M" versus frequency plot reveals a relaxation peak, which is not observed in the ε″ plot and it has been found that this peak is a non-Debye-type. The frequency dependent conductivity plot shows three regions of conduction processes, i. e., a low-frequency region due to DC conduction, a mid-frequency region due to translational hopping motions and a high-frequency region due to localized hopping and/or reorientational motion.http://dx.doi.org/10.5755/j01.ms.17.2.490

Anderson-Stuart Model to Analyze AC and DC Conductivity of Lithium Zinc-Silicate Glass / Glass-Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 919-924
Author(s):  
M.S. Jogad ◽  
V.K. Shrikhande ◽  
A.H. Dyama ◽  
L.A. Udachan ◽  
Govind P. Kothiyal
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Low Frequency ◽  
Frequency Region ◽  
Dc Conductivity ◽  
Frequency Range ◽  
High Frequency Region ◽  
Dc Conductivities ◽  
Conductivity Variation ◽  
Different Temperatures

AC and DC conductivities have been measured by using the real (e¢) and imaginary (e¢¢) parts of the dielectric constant data of glass and glass-ceramics (GC) at different temperatures in the rage 297-642K and in the frequency range 100 Hz to 10 MHz. Using Anderson –Stuart model, we have calculated the activation energy, which is observed to be lower than that of the DC conductivity. The analysis for glass/glass-ceramics indicates that the conductivity variation with frequency exhibits an initial linear region followed by nonlinear region with a maximum in the high-frequency region. The observed frequency dependence of ionic conductivity has been analyzed within the extended Anderson–Stuart model considering both the electrostatic and elastic strain terms. In glass/glassceramic the calculations based on the Anderson-Stuart model agree with the experimental observations in the low frequency region but at higher frequencies there is departure from measured data.

Raman Scatteringl And Infrared Absorption in Lithium Intercalated MoS2

1988 ◽  
Vol 135 ◽  
Author(s):  
T. Sekine ◽  
C. Julien ◽  
M. Jouanne ◽  
M. Weber ◽  
M. Balkanski
Keyword(s):  
High Frequency ◽  
Room Temperature ◽  
Low Frequency ◽  
Host Lattice ◽  
Ir Absorption ◽  
High Frequency Region ◽  
Superlattice Structure ◽  
Layer Mode ◽  
Rigid Layer ◽  
Substitutional Defects

AbstractRaman scattering and IR absorption were studied in Li-intercalated MoS2 at room temperature. After intercalation, new Raman peaks were observed at low-frequency sides of the high-frequency original Raman peaks and around a rigid-layer mode. This fact indicates the formation of superlattice structure along the c-axis. An intercalation mode in which Li atoms vibrate strongly against the host lattice was observed at about 205 cm−1. Two new broad bands grow in the high-frequency region as the concentration of Li increases. The corresponding peaks were observed by IR absorption. They appears to be caused by vibrations of substitutional defects, in which the Li atoms have substituted for Mo atoms in the host lattice.

A Thin Cloud Removal Method for Optical Image Based on Improved Homomorphism Filtering

2014 ◽  
Vol 618 ◽  
pp. 519-522
Author(s):  
Guang Yu ◽  
Wen Bang Sun ◽  
Gang Liu ◽  
Mai Yu Zhou
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Frequency Component ◽  
Frequency Region ◽  
High Frequency Region ◽  
Filtering Method ◽  
Thin Cloud ◽  
Cloud Removal ◽  
Thin Cloud Removal ◽  
Image Definition

Optical remote image is affected by thin cloud inevitably, which debases image definition. Traditional homomorphism filtering frequently used in thin cloud removing has affect on the cloud in low frequency region, but is not effective for those in high frequency region. An improved homomorphism filtering method is proposed on the basis of statistical characters of image information. Instead of the filtering in frequency field, it isolates the low frequency component of the image representing cloud information with calculating neighborhood average in spatial field. Then, the filtered image is enhanced based on rough set. The experiment results show that the proposed method compared to traditional methods can obtain good results and performs faster.

Modeling of Perforated Screens or Membrane Using Rigid Frame Porous Models Combined with Thin Membrane Resonance Sound Absorbing Theory

2013 ◽  
Vol 357-360 ◽  
pp. 1206-1211
Author(s):  
Xiao Ling Gai ◽  
Xian Hui Li ◽  
Bin Zhang ◽  
Peng Xie ◽  
Zhi Hui Ma
Keyword(s):  
High Frequency ◽  
Sound Absorption ◽  
Mass Density ◽  
Low Frequency ◽  
Frequency Region ◽  
Thin Membrane ◽  
High Frequency Region ◽  
Rigid Frame ◽  
Membrane Resonance

The sound absorption ability of screen or perforated membrane is studied based on rigid frame porous models combined with thin membrane resonance sound absorbing theory in this paper. Results show that the sound absorption of screen or perforated membrane is better considering the role of membrane than using the rigid frame porous models when the mass density of screen or perforated membrane is smaller. The rigid frame porous model is very accuracy to model the sound absorption ability of screen or perforated membrane when the mass density of membrane is greater. The parameter studies present that the sound absorption peaks move toward low frequency region with the increasing of the depth of air-back cavity, mass density and thickness of screens or perforated membrane and moves toward high frequency region with the increasing of the perforation and perforated radius of screens or perforated membrane when other parameters keep invariant.

scholarly journals Image Fusion Algorithm at Pixel Level Based on Edge Detection

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jiming Chen ◽  
Liping Chen ◽  
Mohammad Shabaz
Keyword(s):  
Edge Detection ◽  
Image Fusion ◽  
High Frequency ◽  
Low Frequency ◽  
Frequency Region ◽  
Experimental Comparison ◽  
Fusion Algorithm ◽  
High Frequency Region ◽  
Running Time ◽  
Low Efficiency

In the present scenario, image fusion is utilized at a large level for various applications. But, the techniques and algorithms are cumbersome and time-consuming. So, aiming at the problems of low efficiency, long running time, missing image detail information, and poor image fusion, the image fusion algorithm at pixel level based on edge detection is proposed. The improved ROEWA (Ratio of Exponentially Weighted Averages) operator is used to detect the edge of the image. The variable precision fitting algorithm and edge curvature change are used to extract the feature line of the image edge and edge angle point of the feature to improve the stability of image fusion. According to the information and characteristics of the high-frequency region and low-frequency region, different image fusion rules are set. To cope with the high-frequency area, the local energy weighted fusion approach based on edge information is utilized. The low-frequency region is processed by merging the region energy with the weighting factor, and the fusion results of the high findings demonstrate that the image fusion technique presented in this work increases the resolution by 1.23 and 1.01, respectively, when compared to the two standard approaches. When compared to the two standard approaches, the experimental results show that the proposed algorithm can effectively reduce the lack of image information. The sharpness and information entropy of the fused image are higher than the experimental comparison method, and the running time is shorter and has better robustness.

On the Assignment and Directional Dispersion of Polar Phonon Modes in K3Cu(CN)4 and K3Ag(CN)4

1974 ◽  
Vol 29 (7) ◽  
pp. 1011-1016
Author(s):  
W. Nitsch ◽  
H. J. Falge ◽  
R. Claus
Keyword(s):  
Light Scattering ◽  
High Frequency ◽  
Low Frequency ◽  
Frequency Region ◽  
Longitudinal Vibrations ◽  
Phonon Modes ◽  
High Frequency Region ◽  
Single Crystalline ◽  
Scattering Measurements ◽  
Stretching Vibrations

Polar phonon modes in single crystalline K3Cu(CN)4 and K3Ag(CN)4 have been experimentally studied by light scattering. Measurements at 293, 82 and 6 K made possible assignments in the low frequency region from 0 to about 700 cm-1 and the high frequency region from 2030 to about 2100 cm-1 originating from the C≡N stretching vibrations. Directional dispersion due to the anisotropy of K3Cu(CN)4 has been studied and allowed the identification of the transversal and longitudinal vibrations in the high frequency region. IR-reflectivity measurements, partly on the basis of the ATR-method, have been used in order to support the assignments in this region.

scholarly journals Specifications of Resonant Acoustic Rotating Waves in Circular and Annular Domains

2020 ◽  
Vol 19 ◽  
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Modern Technology ◽  
Frequency Region ◽  
High Frequency Region ◽  
Rotating Waves ◽  
Vibration Properties ◽  
Frequency Branch ◽  
Angular Velocities ◽  
Annular Domains

Circular and annular domains of hydroacoustic vibration are very common in modern technology due to their simplicity. On the other hand it turns out that such a shape possesses remarkable vibration properties. It is determined that there are two classes of resonant rotating waves, predominantly tangential and predominantly radial, in terms of prevalence of tangential or radial components of the vectors of vibrational velocities and displacements. The complete map of resonant angular velocities shows that all predominantly tangential angular velocities for all values of ring thickness are assembled into the self-isolating unique single low-frequency branch, whereas predominantly radial ones fill the entire high-frequency region very densely.

Cochlear Implant Combined with a Linear Frequency Transposing Hearing Aid

2012 ◽  
Vol 23 (09) ◽  
pp. 722-732 ◽  
Author(s):  
Håkan Hua ◽  
Björn Johansson ◽  
Radi Jönsson ◽  
Lennart Magnusson
Keyword(s):  
High Frequency ◽  
Repeated Measures ◽  
Hearing Aid ◽  
Low Frequency ◽  
Sound Field ◽  
Frequency Region ◽  
Swedish Version ◽  
High Frequency Region ◽  
Linear Frequency ◽  
Contralateral Ear

Background: Adults with cochlear implants (CIs) are usually implanted unilaterally. To preserve binaural advantages, a noninvasive method involves maintaining the hearing aid (HA) on the contralateral ear; the choice of HA for this purpose is therefore crucial. In recent years, the use of frequency transposition has gained a renewed interest in clinical practice. This type of processing records information from the high-frequency region and conveys it to a low-frequency region where there is still some residual hearing. Purpose: To conduct an investigation and examine whether adults with unilateral CI derive benefits from a HA utilizing linear frequency transposition (LFT) on the contralateral ear. Research Design: A two-period, single-blind, repeated-measures crossover design was conducted to examine the combination of LFT in conjunction with a CI. Speech recognition tests were performed in quiet and in noise with LFT either activated or deactivated. The Speech, Spatial and Qualities of Hearing Questionnaire (SSQ) was used to measure subjective benefit. Study Sample: The participants were nine frequent bimodal users, five males and four females, with a moderate to profound high-frequency sensorineural hearing loss in the nonimplanted ear. Intervention: The current study was conducted using the Widex Mind440 power (m4-19) behind-the-ear HA. The participants acted as their own control in a total of seven conditions: (1) bimodal with own HA, (2) CI only, (3) own HA alone, (4) bimodal new HA LFT-off, (5) new HA LFT-off, (6) bimodal new HA LFT-on, and (7) new HA LFT-on. Data Collection and Analysis: Monosyllabic words in quiet and the Swedish version of Hearing in Noise Test (HINT) were used as speech test materials. Stimuli were presented in sound field at a speech level of 65 dB sound pressure level (SPL) via a loudspeaker at a distance of 1 m from the participant in a sound-treated room. The SSQ was administered in each session evaluating the three bimodal conditions. SPSS software was used for statistical analyses. General linear model (GLM) analysis of variance for repeated measures was performed and followed with Bonferroni-adjusted post hoc pairwise comparisons. Results: Participants performed better with CI only than with HA alone, and the bimodal conditions were superior to the CI alone. No significant differences (p > .05) were observed when comparing the LFT-on with LFT-off regardless of whether the use of CI was included in the different listening conditions in objective and subjective measurements. Conclusions: The results suggest an advantage for CI patients with a HA in the opposite ear, and that the LFT neither degraded nor enhanced speech performance in conjunction with a CI in quiet or in noise in comparison to when it was deactivated.

Analysis on the Mechanical and Electrical Properties of PI/MWNTs Nano-Hybrid Films

2011 ◽  
Vol 675-677 ◽  
pp. 1241-1244
Author(s):  
Ming Yan Zhang ◽  
Peng He Diao ◽  
Xiao Ying Zhu
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
In Situ Polymerization ◽  
Low Frequency ◽  
Frequency Region ◽  
Hybrid Films ◽  
Polyimide Films ◽  
High Frequency Region ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

In this paper, MWNTs (multi-walled carbon nanotubes) were modified by the mixture acid of H2SO4 and HNO3, the PI (polyimide)/MWNTs nano-hybrid films were prepared by means of ultrasonic vibration and in-situ polymerization. The surface morphology was characterized by SEM, the chemical structure was characterized by FT-IR. The tensile strength and Young’s modulus increased at first and then decreased with the increase of MWNTs content. The dielectric constant was tested at a frequency of 1 kHz. The dielectric constant had no obvious variation when MWNTs content was less than 2.9 wt%, as the MWNTs content exceeded 5.36 wt%, the dielectric constant increased rapidly. In general, the dielectric loss of PI/MWNTs nano-hybrid films was higher than the dielectric loss of pure polyimide films. The dielectric loss increased slowly in low frequency region but rapidly in high frequency region. All the test results were attributed to the dispersion degree of MWNTs doping and the combination degree between PI matrix and modified MWNTs in PI/MWNTs nano-hybrid films.

DIELECTRIC PROPERTIES OF PLASMA POLYMERIZED N,N,3,5 TETRAMETHYLANILINE THIN FILMS

2011 ◽  
Vol 18 (01n02) ◽  
pp. 53-60 ◽  
Author(s):  
H. AKTHER ◽  
A. H. BHUIYAN
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Relaxation Times ◽  
Electrical Conductance ◽  
Low Frequency ◽  
Ring Structure ◽  
Frequency Region ◽  
Localized States ◽  
High Frequency Region ◽  
Capacitively Coupled

Plasma polymerized thin films of aluminium/thin film/aluminium configuration were deposited at room temperature by a parallel plate capacitively coupled glow discharge reactor using N,N,3,5 tetramethylaniline (TMA) as a precursor. The infrared spectroscopic analyses revealed that plasma polymerized TMA (PPTMA) films contained an aromatic ring structure with NC and CH side groups, presence of C = O was also evident. The differential thermal analysis and thermogravimetric analysis of PPTMA thin film was thermally stable up to about 505 K. The scanning electron microscopy of PPTMA thin film showed a smooth, flawless and pinhole free surface. The capacitance and ac electrical conductance of PPTMA thin films were measured as functions of frequency (100 < f < 105 Hz) and temperature (300 < T < 450 K). The electrical conductivity is more dependent on temperature in the low frequency region than that in the high frequency region. In PPTMA thin films the conduction may be dominated by hopping of carriers between the localized states at low temperatures and thermally excited at the high temperatures. The activation energies are estimated to be about 0.05 eV in the low temperature and 0.23 eV in the high temperature. Dielectric constant decreases with the increase of frequency and that decreases with the increase of temperature but dielectric loss increases with increasing frequency with a minimum in the low frequency region. The temperature-dependence of the Cole-Cole diagram shows the existence of distribution of dielectric relaxation times in the PPTMA thin films.

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