Influence of Gamma Radiation on the Radiofrequency Dielectric Properties of Nigerian Crude Oil

2009 ◽  
Vol 62-64 ◽  
pp. 445-450
Author(s):  
O.D. Osahon ◽  
O.D. Nworgu
Keyword(s):  
Relaxation Time ◽  
Gamma Radiation ◽  
Crude Oil ◽  
Relative Permittivity ◽  
Room Temperature ◽  
Irradiation Time ◽  
Central Research ◽  
Dielectric Measurements ◽  
Frequency Range ◽  
Dielectric Data

This paper examines the relative permittivity of irradiated and non-irradiated crude oil samples in the frequency range 0.1 – 100.0MHz and room temperature regulated at 25 ± 1oC. Samples of crude oil of mean specific gravity 0.780 ± 0.015 were irradiated for periods of two, four, six, eight and ten months respectively using a gamma radiation source (Cobalt 60) at a dose rate of 0.65mSv per hour. Dielectric measurements were made by using a Boonton RX meter type 250A admittance bridge manufactured by central research Laboratories, Inc, Red, Wing, Minnesota. Analysis of the resulting dielectric data revealed that both the irradiated and non-irradiated samples exhibited dielectric dispersion over the frequency range investigated. However, the relative permittivity values of the irradiated samples were found to be higher than those of the non-irradiated sample. This difference is understandable as it can be attributed to the ionization of atoms and weakening of molecular bonds in the irradiated samples. The increase in relative permittivity for the irradiated samples was observed to be time dependent as the longer the time of irradiation of sample the higher the value of its relative permittivity. Also, in this study, it was observed that the non-irradiated crude oil sample has longer relaxation time than the irradiated ones. The relaxation time decreases gradually with increasing irradiation time. This has physical significance on the basis of the molecular theory of matter and the fact that relaxation time is inversely proportional to relaxation frequency. These results are comparable with the work of other researchers for which similar trends have been observed.

Characterization and dielectric properties of sodium fluoride doped talc

Clay Minerals ◽  
2014 ◽  
Vol 49 (4) ◽  
pp. 551-558
Author(s):  
S. Gümüştas ◽  
K. Köseoğlu ◽  
E. E. Yalçinkaya ◽  
M. Balcan
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Firing Temperature ◽  
Room Temperature ◽  
Dielectric Measurements ◽  
Frequency Range ◽  
Detailed Characterization ◽  
Circuit Element

AbstractThe purpose of this paper is to determine the effect of NaF and firing temperature on the dielectric properties (dielectric constant and dielectric loss) of talc, which is used in the electrical and electronic industries as a circuit element. A detailed characterization of the samples was made by XRD, FTIR, SEM and TG-DTG methods. Dielectric measurements were performed in the frequency range from 1 MHz to 80 MHz at room temperature. The dielectric constant value increased with an increase in firing temperature due to the removal of polarizable compounds from the talc structure. The higher dielectric constant values were obtained by addition of NaF. The dielectric loss of NaF doped talc decreased with the increase of firing temperature and increased with the increase of the amount of NaF.

Ferroelectric Ceramics Related to BaTiO3 for Z5U Multilayer Capacitors

2005 ◽  
Vol 492-493 ◽  
pp. 109-114 ◽  
Author(s):  
Laldja Taïbi-Benziada
Keyword(s):  
Room Temperature ◽  
Ferroelectric Ceramics ◽  
Dielectric Measurements ◽  
Frequency Range ◽  
X Ray ◽  
Solid State Route ◽  
Displacive Phase Transition ◽  
Multilayer Capacitors ◽  
Diffraction Patterns ◽  
Conventional Solid State Route

Several pellets of general formula Ba1-xMx(Ti1-xLix)O3-3xF3x were prepared from BaTiO3, MF2 ( M = Ca, Sr, Ba or Pb ) and LiF powders then sintered by the conventional solid state route at 900 or 1000°C for 1, 2 or 4 hours. X-Ray powder diffraction patterns were collected at room temperature and SEM observations were carried out. Dielectric measurements were performed between 150 and 450K in the frequency range 50Hz - 40MHz. All the ceramics exhibit a very broad ferroelectric displacive phase transition in the temperature range 255K ≤ TC ≤ 328K.The ε' r - T curves and the values of tanδ are compatible with the Z5U class of capacitors. Furthermore, a Debye dielectric relaxation occurs in these oxifluorids in the frequency range 4MHz ≤fr ≤ 38.5MHz.

The Room Temperature Dielectric Spectrum of 2,2-Dimethyl-1 -butanol

1993 ◽  
Vol 48 (12) ◽  
pp. 1231-1233 ◽  
Author(s):  
R. Edelmann ◽  
A. Würflinger ◽  
S. v. Hornhardt ◽  
M. Stockhausen
Keyword(s):  
Relaxation Time ◽  
Room Temperature ◽  
Spectral Shape ◽  
Dielectric Spectrum ◽  
Pure Liquid ◽  
Frequency Range ◽  
Temperature Spectrum ◽  
Plastic Crystals ◽  
Room Temperature Spectrum ◽  
Main Relaxation

Abstract The dielectric spectrum of the title substance ('neohexanol') in its pure liquid state is reported for 293 K up to 71 GHz and, for a restricted frequency range, also for lower temperatures (down to 253 K). The room temperature spectrum resembles that of alicyclic alcohols, in particular cyclopentanol, with respect to spectral shape, main relaxation time and the relation of the latter to viscosity, which similarity may be connected with the fact that these alcohols are able to form 'plastic crystals'.

Magnetic and Dielectric Properties of Barium Magnesium Hexaferrite Epoxy Resin Composite Film

2016 ◽  
Vol 1141 ◽  
pp. 54-56
Author(s):  
Chetna Chauhan ◽  
Reshma Nandotaria ◽  
Rajshree Jotania
Keyword(s):  
Room Temperature ◽  
Epoxy Composite ◽  
Resin Composite ◽  
Synthesis Method ◽  
Dielectric Measurements ◽  
Frequency Range ◽  
Muffle Furnace ◽  
Epoxy Resin Composite ◽  
Suitable Amount ◽  
Solvent Free Synthesis

The W type barium magnesium hexaferrite powder with chemical composition BaMg2Fe16O27with CTAB surfactant was synthesized using solvent free synthesis method. The precursor was calcinated at 950 °C for 6 h in a muffle furnace and then slowly cooled to room temperature in order to obtain barium magnesium hexaferrite powder. The flexible epoxy thick film of Ba-Mg hexaferrite/epoxy composite was fabricated using suitable amount of hardener and curing agent. The field-dependent magnetic properties of the hexaferrite sample were investigated at room temperature using a vibrating sample magnetometer (VSM) with a maximum applied field of 15 kOe. The dielectric measurements were taken at room temperature within the frequency range to 100 Hz to 2 MHz.

Dielectric and orientational properties of nematogenic 4-n-octyl(4′-cyanophenyl)benzoate

2010 ◽  
Vol 18 (1) ◽  
Author(s):  
D. Bauman ◽  
J. Jadżyn ◽  
E. Wolarz ◽  
A. Modlińska ◽  
R. Dąbrowski
Keyword(s):  
Phase Transition ◽  
Relaxation Time ◽  
Dielectric Properties ◽  
Order Parameter ◽  
Orientational Order ◽  
Experimental Studies ◽  
Orientational Order Parameter ◽  
Dielectric Measurements ◽  
Frequency Range ◽  
Dichroic Dye

AbstractExperimental studies of the dielectric properties in the nematic and isotropic phases of 4-cyanophenyl-4′-n-octylbenzoate (8CPB) have been performed in the frequency range from 50 kHz to 100 MHz. The relaxation process related to the rotation around the short molecular axis has been analysed. The results obtained have revealed that in the vicinity of the I-N phase transition, the molecular subdiffusional rotation process occurs. It is connected with the pretransitional effects which are observed both in the static and dynamic dielectric measurements. On the basis of the temperature dependence of the relaxation time in the nematic and isotropic phases, the orientational order parameter 〈P2〉 has been determined. The values of 〈P2〉 obtained in this way have been compared with those evaluated from the measurements of the polarized electronic absorption of the dichroic dye, dissolved as guest probe in the mesogenic host.

scholarly journals Photothermal, Photoelectric, and Photothermoelectric Effects in Bi-Sb Thin Films in the Terahertz Frequency Range at Room Temperature

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 76
Author(s):  
Mikhail K. Khodzitsky ◽  
Petr S. Demchenko ◽  
Dmitry V. Zykov ◽  
Anton D. Zaitsev ◽  
Elena S. Makarova ◽  
...  
Keyword(s):  
Thin Films ◽  
Terahertz Radiation ◽  
Room Temperature ◽  
Voltage Drop ◽  
Radiation Detection ◽  
Radiation Detectors ◽  
Thz Radiation ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Frequency Range

The terahertz frequency range is promising for solving various practically important problems. However, for the terahertz technology development, there is still a problem with the lack of affordable and effective terahertz devices. One of the main tasks is to search for new materials with high sensitivity to terahertz radiation at room temperature. Bi1−xSbx thin films with various Sb concentrations seem to be suitable for such conditions. In this paper, the terahertz radiation influence onto the properties of thermoelectric Bi1−xSbx 200 nm films was investigated for the first time. The films were obtained by means of thermal evaporation in vacuum. They were affected by terahertz radiation at the frequency of 0.14 terahertz (THz) in the presence of thermal gradient, electric field or without these influences. The temporal dependencies of photoconductivity, temperature difference and voltage drop were measured. The obtained data demonstrate the possibility for practical use of Bi1−xSbx thin films for THz radiation detection. The results of our work promote the usage of these thermoelectric materials, as well as THz radiation detectors based on them, in various areas of modern THz photonics.

scholarly journals Dielectric Spectroscopy Analysis of Liquid Crystals Recovered from End-of-Life Liquid Crystal Displays

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2873
Author(s):  
Ana Barrera ◽  
Corinne Binet ◽  
Frédéric Dubois ◽  
Pierre-Alexandre Hébert ◽  
Philippe Supiot ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
End Of Life ◽  
Room Temperature ◽  
Liquid Crystal Displays ◽  
Dielectric Anisotropy ◽  
Frequency Range ◽  
Spectroscopy Analysis ◽  
Diamond Nanoparticles ◽  
Nematic Phases ◽  
Universal Law

In the present work, the dielectric properties of recycled liquid crystals (LCs) (non-purified, purified, and doped with diamond nanoparticles at 0.05, 0.1, and 0.2 wt%) were investigated. The studied LC mixtures were obtained from industrial recycling of end-of-life LC displays presenting mainly nematic phases. Dielectric measurements were carried out at room temperature on a frequency range from 0.1 to 106 Hz using an impedance analyzer. The amplitude of the oscillating voltage was fixed at 1 V using cells with homogeneous and homeotropic alignments. Results show that the dielectric anisotropy of all purified samples presents positive values and decreases after the addition of diamond nanoparticles to the LC mixtures. DC conductivity values were obtained by applying the universal law of dielectric response proposed by Jonscher. In addition, conductivity of the doped LC mixtures is lower than that of the undoped and non-purified LC.

High Frequency Dielectric Response of the Ionic Liquid N-Methyl-N-ethylpyrrolidinium Dicyanamide

2007 ◽  
Vol 60 (1) ◽  
pp. 6 ◽  
Author(s):  
Simon Schrödle ◽  
Gary Annat ◽  
Douglas R. MacFarlane ◽  
Maria Forsyth ◽  
Richard Buchner ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Dielectric Loss ◽  
Dielectric Relaxation ◽  
High Frequency ◽  
Dielectric Response ◽  
Room Temperature ◽  
Room Temperature Ionic Liquid ◽  
Dielectric Relaxation Spectroscopy ◽  
Frequency Range ◽  
Fast Rotation

A study of the room-temperature ionic liquid N-methyl-N-ethylpyrrolidinium dicyanamide by dielectric relaxation spectroscopy over the frequency range 0.2 GHz ≤ ν ≤ 89 GHz has revealed that, in addition to the already known lower frequency processes, there is a broad featureless dielectric loss at higher frequencies. The latter is probably due to the translational (oscillatory) motions of the dipolar ions of the IL relative to each other, with additional contributions from their fast rotation.

Однофотонное излучение одиночной квантовой точки CdTeSe/ZnS в ближнем инфракрасном диапазоне при комнатной температуре

2021 ◽  
Vol 47 (21) ◽  
pp. 3
Author(s):  
Siyue Jin ◽  
Xingsheng Xu
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Auger Recombination ◽  
Single Photon ◽  
Irradiation Time ◽  
Colloidal Quantum Dots ◽  
Single Quantum ◽  
Illumination Time ◽  
Single Quantum Dots ◽  
Single Quantum Dot

In this study, the photostability of a CdTeSe/ZnS colloidal single photon emitter with a wavelength of 800nm at room temperature was investigated. The second-order correlation function was much smaller than 0.1, which proved that the CdTeSe/ZnS single quantum dot at 800nm is a highly pure single-photon emitter. The effects of the irradiation time on the optical properties from single quantum dots were analyzed. As the illumination time increased, the emission of biexciton and multiexciton in the colloidal quantum dots increased, and the occurrence of Auger recombination increased.

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