Free ions in kerosene-based ferrofluid detected by impedance spectroscopy

2021 ◽  
Vol 23 (4) ◽  
pp. 2819-2824
Author(s):  
F. Batalioto ◽  
G. Barbero ◽  
A. F. C. Campos ◽  
A. M. Figueiredo Neto
Keyword(s):  
Impedance Spectroscopy ◽  
Low Frequency ◽  
Frequency Region ◽  
Electric Response ◽  
Free Ions

The influence of the free ions on the electric response of cells filled with kerosene-based ferrofluids in the low-frequency region is explored.

Incoherent inelastic neutron scattering from polyacetylenes in the low-frequency region

1985 ◽  
Vol 10 (4) ◽  
pp. 293-295 ◽  
Author(s):  
M. Tasumi ◽  
I. Harada ◽  
H. Takeuchi ◽  
H. Shirakawa ◽  
S. Suzuki ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Low Frequency ◽  
Inelastic Neutron ◽  
Frequency Region

Investigations of the Optical Properties of LaNi5 and LaNi4.5Sn0.5

2013 ◽  
Vol 321-324 ◽  
pp. 495-498 ◽  
Author(s):  
Dong Chen ◽  
Chao Xu
Keyword(s):  
Experimental Data ◽  
Refractive Index ◽  
Optical Properties ◽  
Density Functional ◽  
Low Frequency ◽  
Potential Method ◽  
Frequency Region ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Pseudo Potential

The reflectivity, loss function, refractive index, extinction coefficient and dielectric function of the LaNi5and LaNi4.5Sn0.5intermetallic compounds are investigated through the plane-wave pseudo-potential method based on the density functional theory. The effects of Sn impurity are discussed and some interesting features are found in the low frequency region. Some important optical properties such as static dielectric constant and static refractive index are obtained. The equation [n (0)]2=ε1(0)is satisfied according to our calculation, which indicates that our results are correct and reasonable. Nevertheless, the calculated results need to be testified in the future due to the lack of experimental data.

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.

scholarly journals Study of Influence of Electrode Geometry on Impedance Spectroscopy

2010 ◽  
Author(s):  
Riaz Ahmed ◽  
Kenneth Reifsnider
Keyword(s):  
Impedance Spectroscopy ◽  
High Frequency ◽  
Low Frequency ◽  
Effective Area ◽  
Ac Impedance ◽  
Local Geometry ◽  
Electrode Geometry ◽  
Electrode Area ◽  
Impedance Response ◽  
Working Electrode

Electrochemical Impedance Spectroscopy (EIS) is a powerful and proven tool for analyzing AC impedance response. A conventional three electrode EIS method was used to perform the investigation in the present study. Saturated potassium chloride solution was used as the electrolyte and three different material rods were used as working electrodes. Different configurations of electrode area were exposed to the electrolyte as an active area to investigate electrode geometry effects. Counter to working electrode distance was also altered while keeping the working electrode effective area constant to explore the AC response dependence on the variation of ion travel distance. Some controlled experiments were done to validate the experimental setup and to provide a control condition for comparison with experimental results. A frequency range of 100 mHz to 1 MHz was used for all experiments. In our analysis, we have found a noteworthy influence of electrode geometry on AC impedance response. For all electrodes, impedance decreases with the increase of effective area of the electrolyte. High frequency impedance is not as dependent on geometry as low frequency response. The observed phase shift angle drops in the high frequency region with increased working electrode area, whereas at low frequency the reverse is true. Resistance and capacitive reactance both decrease with an increase of area, but resistance response is more pronounce than reactance. For lower frequencies, small changes in working area produce very distinctive EIS variations. Electrode material as well as geometry was systematically varied in the present study. From these and other studies, we hope to develop a fundamental foundation for understanding specific changes in local geometry in fuel cell (and other) electrodes as a method of designing local morphology for specific performance.

Low frequency electromagnetic radiation and hearing

2009 ◽  
Vol 123 (11) ◽  
pp. 1204-1211 ◽  
Author(s):  
J Morales ◽  
M Garcia ◽  
C Perez ◽  
J V Valverde ◽  
C Lopez-Sanchez ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Electromagnetic Fields ◽  
Control Animal ◽  
Guinea Pigs ◽  
Low Frequency ◽  
Organ Of Corti ◽  
Outer Hair Cells ◽  
Morphological Alteration ◽  
Electric Response ◽  
Hearing Level

AbstractObjective:To analyse the possible impact of low and extremely low frequency electromagnetic fields on the outer hairs cells of the organ of Corti, in a guinea pig model.Materials and methods:Electromagnetic fields of 50, 500, 1000, 2000, 4000 and 5000 Hz frequencies and 1.5 µT intensity were generated using a transverse electromagnetic wave guide. Guinea pigs of both sexes, weighing 100–150 g, were used, with no abnormalities on general and otic examination. Total exposure times were: 360 hours for 50, 500 and 1000 Hz; 3300 hours for 2000 Hz; 4820 hours for 4000 Hz; and 6420 hours for 5000 Hz. One control animal was used in each frequency group. The parameters measured by electric response audiometer included: hearing level; waves I–IV latencies; wave I–III interpeak latency; and percentage appearance of waves I–III at 90 and 50 dB sound pressure level intensity.Results:Values for the above parameters did not differ significantly, comparing the control animal and the rest of each group. In addition, no significant differences were found between our findings and those of previous studies of normal guinea pigs.Conclusion:Prolonged exposure to electromagnetic fields of 50 Hz to 5 KHz frequencies and 1.5 µT intensity, produced no functional or morphological alteration in the outer hair cells of the guinea pig organ of Corti.

Vibronic side bands of Sm2+ in alkali halides

1969 ◽  
Vol 47 (17) ◽  
pp. 1757-1767 ◽  
Author(s):  
M. Buchanan ◽  
E. J. Woll Jr.
Keyword(s):  
Low Frequency ◽  
Alkali Halides ◽  
Frequency Region ◽  
Defects In Crystals ◽  
Side Band

The calculation of vibronic side bands of defects in crystals is discussed. A model for the deformation of the lattice about a Sm2+ defect in alkali halides and side-band calculations on this model for KBr and KCl containing Sm2+ are compared with experimentally observed side bands. Improvements, particularly in the low frequency region, are found over the calculations assuming no deformation.

scholarly journals Monoclinic Li2TiO3 Nano-particles via sol-gel method: Structure and impedance spectroscopy

2019 ◽  
Vol 8 (3) ◽  
pp. 209
Author(s):  
Fatima Zahra Krimech ◽  
Salaheddine Sayouri ◽  
Taj-Edine Lamcharfi ◽  
Fatima Zahra Ahjyaje
Keyword(s):  
Impedance Spectroscopy ◽  
Sol Gel ◽  
Low Frequency ◽  
Transport Processes ◽  
Nano Particles ◽  
Secondary Phases ◽  
Conventional Solid State Reaction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Heat Treated

<p>Pure phase Li<sub>2</sub>TiO<sub>3 </sub>nano-particles were synthesized by the sol-gel method and the structural properties were examined with X-ray diffraction (XRD) technique. The latter showed that these materials, heat treated at relatively low temperature 900°C during 4h compared to the conventional solid-state reaction which calcination temperature is about 900–1100°C for 10 h; crystallize in the monoclinic phase without the presence of secondary phases. The microstructure of the LT ceramic (sintered at 1100°C) were determined by SEM and a good crystalline nature was observed with an average of granular size 2 μm. Moreover, the impedance spectroscopy showed at a higher temperature of 500°C the low-frequency arc due either to the grain boundary or sample-electrode charge transport processes.</p>

scholarly journals The active dynamic vibration damper in non-stationary operation of a vibroactive unit

2021 ◽  
pp. 13-17
Author(s):  
D. V. Sitnikov ◽  
◽  
A. A. Burian ◽  
Keyword(s):  
Vibration Isolation ◽  
Low Frequency ◽  
Resonance Region ◽  
Frequency Region ◽  
Vibration Damper ◽  
Passive System ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Dynamic Vibration ◽  
Impulse Characteristics

The paper considers a vibration isolation system, in which a force is applied to the moving mass of the active dynamic vibration damper by an actuator in proportion to the measured value of the base response. The amplitude-frequency and impulse characteristics are plotted depending on the parameters of the system, assuming the actuator without distortion generates the force proportional to the base response. It is shown that the considered vibration isolation system is quite effective in the low-frequency region, including in the resonance region of the passive system, both in stationary and nonstationary modes of vibroactive forces

Sign in / Sign up

Export Citation Format

Share Document