Dielectric behavior and electric strength of polymer films in varying thermal conditions for 5 Hz to 1 MHz frequency range

2002 ◽  
Author(s):  
G. Yilmaz ◽  
O. Kalenderli
Keyword(s):  
Polymer Films ◽  
Thermal Conditions ◽  
Dielectric Behavior ◽  
Electric Strength ◽  
Frequency Range

scholarly journals Soil Moisture Estimate Uncertainties from the Effect of Soil Texture on Dielectric Semiempirical Models

2020 ◽  
Vol 12 (14) ◽  
pp. 2343
Author(s):  
Jing Liu ◽  
Qinhuo Liu
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Texture ◽  
Dielectric Behavior ◽  
Volumetric Water Content ◽  
Frequency Range ◽  
Dielectric Model ◽  
Texture Effect ◽  
Semi Empirical ◽  
Semiempirical Models

Soil texture has been shown to affect the dielectric behavior of soil over the entire frequency range. Three universally employed dielectric semiempirical models (SEMs), the Dobson model, the Wang–Schmugge model and the Mironov model, as well as a new improved SEM known as the soil semi-empirical mineralogy-related-to-water dielectric model (SSMDM), incorporate a significant soil texture effect in different ways. In this paper, soil moisture estimate uncertainties from the effect of soil texture on these four SEMs are systematically and widely investigated over all soil texture cases at different frequencies between 1.4 and 18 GHz for volumetric water content levels between 0.0 and 0.4 m3/m3 from the perspective of two aspects: soil dielectric model discordance and soil texture discordance. Firstly, the effect of soil texture on these four dielectric SEMs is analyzed. Then, soil moisture estimate uncertainties due to the effect of soil texture are carefully investigated. Finally, the applicability of these SEMs is discussed, which can supply references for their choice. The results show that soil moisture estimate uncertainties are small and satisfy the 4% volumetric water content retrieval requirement in some cases. However, in other cases, it may contribute relatively significant uncertainties to soil moisture estimates and correspond to a difference that exceeds the 4% volumetric water content requirement, with potential for the largest deviations to exceed 0.22 m3/m3.

AN APPARATUS FOR THE MEASUREMENT OF DIELECTRIC CONSTANTS OF ADSORBED GASES AT FREQUENCIES UP TO 100 Mc./Sec.

1955 ◽  
Vol 33 (2) ◽  
pp. 268-278 ◽  
Author(s):  
M. H. Waldman ◽  
R. McIntosh
Keyword(s):  
Sulphur Dioxide ◽  
Experimental Error ◽  
Dielectric Behavior ◽  
Dielectric Constants ◽  
Frequency Range

The design of an apparatus suitable for the measurement of dielectric constants at frequencies up to 106 Mc./sec. is shown. The apparatus was used to measure changes in capacitance with volume adsorbed for the system sulphur dioxide – rutile at about 3.5 °C. and for frequencies of 13, 36, and 106 Mc./sec. The results failed to reveal any dispersion due to the adsorbed matter in this frequency range. The dielectric behavior observed is the same, within experimental error of a few per cent, as that found by Channen and McIntosh for the same system at 3.7 Mc./sec.

Thin insulating polymer films as dielectric layers for phthalocyanine-based organic field effect transistors

2006 ◽  
Vol 10 (10) ◽  
pp. 1179-1189 ◽  
Author(s):  
Christian Kelting ◽  
Wilfried Michaelis ◽  
Andreas Hirth ◽  
Dieter Wöhrle ◽  
Derck Schlettwein
Keyword(s):  
Thin Films ◽  
Polymer Films ◽  
Field Effect ◽  
Field Effect Transistors ◽  
High Vacuum ◽  
Dielectric Behavior ◽  
Organic Field Effect Transistors ◽  
Electrical Measurements ◽  
Dielectric Layers ◽  
Vis Spectroscopy

Films of organic polymers were prepared and investigated as insulating layers in contact with phthalocyanines as organic semiconductors for use in organic field effect transistors. The polymer films were obtained either by a high-vacuum technique based on the thermal decomposition of polymers and polymerization of the fragments on a substrate, by the spin-coating of polymer solutions or by the cross-linking of spin-coated precursors. Poly(vinylchloride), poly(vinylidenefluoride), poly(acrylonitrile), poly(methylmethacrylate), poly( N -vinylpyrrolidone), poly(styrene), poly(4-vinylpyridine), poly( N -vinylcarbazole) and a polyimide were used as polymers. The film growth was studied by mass spectrometry and infrared spectroscopy. Electrochemical measurements by cyclic voltammetry served to analyze the properties of the polymer films. The morphology was determined by atomic force microscopy. Interactions of the films with phthalocyaninatozinc ( PcZn ) was analyzed for co-evaporated PcZn in the polymer films, to probe the chemical compatibility of the methods. Subsequently, evaporated PcZn or hexadecafluorophthalocyaninato-oxo-vanadium ( F 16 PcVO ) thin films were studied in detail by UV-vis spectroscopy and by electrical measurements to investigate interface formation, intermolecular coupling and electrical conduction in such films. The applicability of the different polymers as dielectric layers in organic field effect transistors, with phthalocyanines as the active semiconductor thin films, is discussed, based on their dielectric behavior and observed growth characteristics.

scholarly journals Sound speed and attenuation in thin polymer films in the frequency range 0.2–1 GHz

1984 ◽  
Vol 75 (S1) ◽  
pp. S33-S33
Author(s):  
G. M. Sessler ◽  
R. Gerhard‐Multhaupt ◽  
J. E. West
Keyword(s):  
Polymer Films ◽  
Sound Speed ◽  
Thin Polymer Films ◽  
Frequency Range ◽  
Thin Polymer

scholarly journals Electromagnetic Characterization of a Composite (RE-CB-MT) by Time Domain Spectroscopy

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Amina Bounar ◽  
Nacerdine Bouzit ◽  
Nacerdine Bourouba
Keyword(s):  
Time Domain ◽  
Ternary Mixture ◽  
Strong Dependence ◽  
Low Frequency ◽  
Theoretical Models ◽  
Dielectric Behavior ◽  
Frequency Range ◽  
Time Domain Spectroscopy ◽  
Percolation Phenomenon

The aim of this article is to study the dielectric behavior (ε, σ) in microwaves domain of composites made with Epoxy Resin (RE), Carbon Black (CB), and Magnesium Titanate (MT) on a large band of frequency. This kind of composites is very solicited for applications and miniaturization of the components circuits (cavities, antennas, substrates, etc.) in hyperfrequency electronics. In this study we have also highlighted the effect of the fillers nature and their concentrations on the behavior of these composites. The results obtained by time domain spectroscopy (TDS) have revealed the strong dependence of complex permittivity of the composite materials on both the nature and the concentration of conductive environment. Low frequency analysis (500 MHz) has been investigated to determine the conductivity of composites which is related to the percolation phenomenon. Moreover, the comparison between experimental results and theoretical models shows that the modeling Lichtenecker law is applicable to the ternary mixture in this frequency range and is in accordance with the approach postulated by Bottreau.

Investigation of dielectric behavior of thermally aged XLPE cable in the high-frequency range

2006 ◽  
Vol 25 (4) ◽  
pp. 553-561 ◽  
Author(s):  
Chonung Kim ◽  
Zhijian Jin ◽  
Pingkai Jiang ◽  
Zishu Zhu ◽  
Genlin Wang
Keyword(s):  
High Frequency ◽  
Dielectric Behavior ◽  
High Frequency Range ◽  
Frequency Range ◽  
Xlpe Cable

scholarly journals Simulation of impedance measurements at human forearm within 1 kHz to 2 MHz

2019 ◽  
Vol 7 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Gautam Anand ◽  
Andrew Lowe ◽  
Ahmed M. Al-Jumaily
Keyword(s):  
High Frequency ◽  
Simulation Analysis ◽  
Electrical Response ◽  
Dielectric Behavior ◽  
Cole Plot ◽  
Frequency Range ◽  
Impedance Measurements ◽  
High Frequency Structure Simulator ◽  
Human Forearm ◽  
Different Diameters

Abstract This work presents a simulation analysis of the bioimpedance measurements at the human forearm. The Ansys® High Frequency Structure Simulator (HFSS) has been used to analyze the electrical response of a section of human forearm with three domains of dielectric behavior – fat, muscle and artery (blood). The impedance values were calculated as the ratio of the output voltage at the electrodes to the applied known current (1 mA). A model was developed and was simulated for impedance values obtained within a frequency range of 1 kHz to 2 MHz. The measurements were done at three instances of radial artery diameter. The maximum resistance and reactance values were calculated as 445 Ω and 178.5 Ω, 356 Ω and 138 Ω, and 368 Ω and 144.3 Ω for diameters 2.3 mm, 2.35 mm, and 2.4 mm respectively. The set of impedance values obtained followed the Cole-plot trend. The results obtained were found to be in excellent agreement with the Cole modelling. The set of values obtained at three different diameters reflected the effect of blood flow on impedance values.

Sign in / Sign up

Export Citation Format

Share Document