Predicting dielectric constants of pure liquids: fragment-based Kirkwood–Fröhlich model applicable over a wide range of polarity

Polyhedral oligomeric silsesquioxane (POSS) nanoparticles have been successfully incorporated into thermoplastic and thermoset polymers via copolymerization, grafting, blending, surface bonding, or other transformations. A great promise in the development of a wide range of POSS-containing nanocomposites with diversely improved properties has been displayed. Thermal properties, viscoelastic properties, mechanical strengths, dielectric constants, surface hydrophobicity and flame-retardancy of the nanocomposites are easily varied to target properties by adjusting POSS structure, crosslink density, processing condition, etc. Investigations on the effects of POSS molecular geometry, composition, and concentration on physical and mechanical properties of resultant POSS-modified thermoplastic and thermosetting nanocomposites have been carefully reviewed in this article.

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Microwave properties of drilling fluids

Geophysics ◽

10.1190/1.1441203 ◽

1981 ◽

Vol 46 (3) ◽

pp. 322-332 ◽

Cited By ~ 2

Author(s):

James N. Lange ◽

Steven S. Shope

Keyword(s):

Dielectric Constant ◽

Dielectric Properties ◽

Weight Percent ◽

Dielectric Constants ◽

Drilling Fluids ◽

Nanosecond Pulses ◽

Microwave Attenuation ◽

In Situ Conditions ◽

Wide Range

The application of electromagnetic (EM) techniques to well logging is initiated in an environment dominated by the properties of the drilling fluids. An impulse technique using nanosecond pulses is applied to a coaxial waveguide containing drilling fluids to measure the velocity (dielectric constant ε) and absorption (attenuation coefficient α) of EM impulses. It is the large difference in dielectric constants of water and oil which makes EM propagation techniques attractive for logging. Dielectric properties of some nondispersed drilling fluids (bentonite and attapulgite clays) are found to be largely dependent upon the volume of water present. Both bentonite and attapulgite clays exhibit the same range of dielectric constants (ε = 81 → 75) when the weight percent of clay is increased to 10 percent. In contrast, the microwave attenuations of these two clays are quite different, with that of the bentonite increasing at about 4 times the rate of the attapulgite suspensions. Microwave attenuation measured for a variety of commercial drilling fluids varies over a wide range, with the lignosulfonates the largest (91 dB/m) and oil inverts the smallest (3 dB/m). The oil inverts also have a small dielectric constant (ε = 3 → 6). Temperature dependence of the attenuation for these same drilling fluids is determined in the range from 23 °C to 45 °C to indicate their behavior under in situ conditions.

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HIGH DIELECTRIC PROPERTIES OF LOW-TEMPERATURE SINTERED (Ca0.5Cu0.5)TiO3 CERAMICS

Journal of Advanced Dielectrics ◽

10.1142/s2010135x11000197 ◽

2011 ◽

Vol 01 (02) ◽

pp. 203-207 ◽

Cited By ~ 2

Author(s):

JIAN-CONG YUAN ◽

YUAN-HUA LIN ◽

BO CHENG ◽

CE-WEN NAN

Keyword(s):

Dielectric Properties ◽

Sintering Temperature ◽

Sol Gel ◽

Impedance Spectrum ◽

Dielectric Constants ◽

Sintering Process ◽

Remarkable Effect ◽

High Dielectric Permittivity ◽

Wide Range ◽

High Dielectric

High dielectric-permittivity ( Ca0.5Cu0.5)TiO3 -based ceramics have been prepared by a sol-gel method combined with a solid state sintering process. The results indicate that the additives of H3BO3 have a remarkable effect on the sintering temperature, microstructure and dielectric properties. High density ( Ca0.5Cu0.5)TiO3 bulk ceramics can be obtained after sintering at 900°C. The as-sintered ceramics show high dielectric constants (~1000), and low losses (~0.05). The dielectric properties are nearly independent of frequency and temperature in a wide range. The activation energy is calculated as about 0.50 eV by impedance spectrum method.

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New hybrid low-k dielectric materials prepared by vinylsilane polymerization

MRS Proceedings ◽

10.1557/proc-812-f3.6 ◽

2004 ◽

Vol 812 ◽

Cited By ~ 3

Author(s):

Jung-Won Kang ◽

Byung Ro Kim ◽

Gwi-Gwon Kang ◽

Myung-Sun Moon ◽

Bum-Gyu Choi ◽

...

Keyword(s):

Fracture Toughness ◽

Hybrid Materials ◽

Dielectric Materials ◽

Dielectric Constants ◽

Good Adhesion ◽

Inorganic Hybrid ◽

Adhesion Promoters ◽

Semiconductor Structures ◽

Wide Range ◽

Low K

AbstractSpin-on Low-K materials are potentially very attractive as interconnection materials in a wide range of semiconductor structures. In this work, new organic-inorganic hybrid materials synthesized by vinylsilane polymerization were proposed. According to compositions and additional fabrications, dielectric constants of these materials were evaluated to be 2.3∼3.1. The hardness was 2.0GPa after 430°C curing. These materials had good adhesion strength such that fracture toughness on silicon wafer was 0.22 MPam0.5 without any adhesion promoters. This result indicates that these organicinorganic hybrid materials are very promising candidates for low-K dielectrics.

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Electrical properties of Athabasca Oil Sands

Canadian Journal of Earth Sciences ◽

10.1139/e79-187 ◽

1979 ◽

Vol 16 (10) ◽

pp. 2009-2021 ◽

Cited By ~ 12

Author(s):

F. S. Chute ◽

F. E. Vermeulen ◽

M. R. Cervenan ◽

F. J. McVea

Keyword(s):

Electrical Properties ◽

Moisture Content ◽

Oil Sands ◽

Relative Dielectric Constant ◽

Dielectric Constants ◽

Graphical Form ◽

Oil Sand ◽

Wide Range ◽

Realistic Assessment

The results of a series of laboratory measurements of the electrical properties of samples of oil sand from the Athabasca deposit in northeastern Alberta are reported. The electrical conductivity and relative dielectric constant of the samples have been determined over a frequency range extending from 50–109 Hz. The measurements were performed on samples with a wide range of moisture content and over a temperature range from about 3–150 °C. A discussion of the methods and apparatus used is included.Sufficient data have been collected to permit correlation of the electrical properties of oil sand with density, moisture content, and temperature, and hence to indicate how the laboratory results can be extended to estimate in situ conductivities and dielectric constants. The results of these correlations, which are presented in graphical form, are of fundamental importance in any realistic assessment of the viability of electromagnetically heating large in situ deposits of oil sand.

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Processing and Characterization of Silica Xerogel Films for Low-K Dielectric Applications

MRS Proceedings ◽

10.1557/proc-565-29 ◽

1999 ◽

Vol 565 ◽

Cited By ~ 12

Author(s):

Anurag Jain ◽

Svetlana Rogojevic ◽

Satya V. Nitta ◽

Venumadhav Pisupatti ◽

William N. Gill ◽

...

Keyword(s):

Ambient Pressure ◽

Concrete Surface ◽

Dielectric Constants ◽

Silica Xerogel ◽

High Porosity ◽

Wide Range ◽

Order Of Magnitude ◽

Lift Off ◽

Surface Modified ◽

Xerogel Films

AbstractSurface modified silica xerogel films of high porosity (60 - 90 %) and uniform thickness (0.4–2 μm) were fabricated at ambient pressure on silicon and silicon dioxide. The rheological properties that govern film uniformity were determined. A relation between the final dried film thickness and spin speed was developed. The porosity and thickness of the films could be controlled independently. The same porosity could be obtained over a wide range of aging time and temperature combinations. Fracture toughness was measured using the edge-lift-off technique. The best values were comparable to concrete. Surface modification was affected by treating the film with trimethylcholorosilane (TMCS) and other modifiers. Moisture adsorption was studied at 100% RH using a quartz crystal microbalance technique. Depending upon the degree and kind of surface treatment, films absorbed as much as 32% or as little as 2% of their weight in water. Dielectric constants (K), losses and breakdown strengths were comparable to values for calcined, bulk aerogels. Thin (≤ 500 Å) films of Copper (Cu) and Tantalum (Ta) were deposited on xerogel films and subjected to thermal annealing. No diffusion was observed within the limits of RBS. High-density plasma etching showed that the films etch an order of magnitude faster than conventional SiO2 films.

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Intermolecular association and dielectric relaxation in some liquid amides

Canadian Journal of Chemistry ◽

10.1139/v68-523 ◽

1968 ◽

Vol 46 (20) ◽

pp. 3143-3149 ◽

Cited By ~ 31

Author(s):

Walter Dannhauser ◽

Gyan P. Johari

Keyword(s):

Alkyl Group ◽

Relaxation Times ◽

Correlation Factor ◽

Dielectric Constants ◽

Temperature Analysis ◽

Size And Shape ◽

Linear Chains ◽

Wide Range ◽

Intermolecular Association ◽

Debye Equation

The equilibrium dielectric constants of three isomeric N-methylvaleramides are reported over a wide range of temperature. Analysis of the data in terms of Kirkwood's correlation factor suggests that the liquids are extensively associated into linear chains and that the extent of association is essentially independent of the size and shape of the alkyl group. Dielectric dispersion was measured (0.5–200 MHz) for these compounds as well as the isomeric N-butylacetamides and also N-ethylacetamide. The dispersion loci all follow the Debye equation and the relaxation times show a specific dependence on the size and shape of the alkyl group, but not on whether it is in the acid or the amine position. Activation energies for relaxation, viscous flow, and conduction are compared and the nature of liquid N-mono-substituted amides is discussed.

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LGS and LGN Microresonators: Applications to High Temperature Nanobalances

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.51.191 ◽

2006 ◽

Vol 51 ◽

pp. 191-196 ◽

Cited By ~ 1

Author(s):

Therese G. Leblois

Keyword(s):

High Temperature ◽

Electromechanical Coupling ◽

Dielectric Constants ◽

Data Sets ◽

Coupling Coefficients ◽

New Materials ◽

Wide Range ◽

Modes Of Vibration ◽

Acoustic Wave Devices ◽

Zero Frequency

New materials such as langasite and langanate crystals present some interesting perspectives for acoustic wave devices due to strong piezoelectric coefficients and due to the opportunity to work through a wide range of temperature. Theoretical formulations for temperature coefficients and electromechanical coupling coefficients of resonators are given in the case of thickness modes of vibration. Results are computed using two data sets of elastic, piezoelectric and dielectric constants. Orientations of BAW microresonators which give zero frequency shift versus temperature at 600°C are determined to serve as high temperature nanobalances.

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Preparation and Properties of Polyisoimides as a Highly Dimensionally Stable Polyimide Precursor with Low Dielectric Constant

High Performance Polymers ◽

10.1088/0954-0083/9/3/011 ◽

1997 ◽

Vol 9 (3) ◽

pp. 333-344 ◽

Cited By ~ 17

Author(s):

Hiroshi Seino ◽

Osamu Haba ◽

Amane Mochizuki ◽

Masahiro Yoshioka ◽

Mitsuru Ueda

Keyword(s):

Dielectric Constant ◽

Dielectric Constants ◽

Isomerization Reaction ◽

Low Dielectric Constant ◽

Low Dielectric ◽

Fluorinated Polyimides ◽

Wide Range ◽

Biphenyltetracarboxylic Dianhydride ◽

Polyimide Precursor ◽

Dipolar Aprotic Solvents

Fluorinated polyimides (PIs) with low dielectric constant and high dimensional stability have been developed using polyisoimides (PIIs) as a polyimide precursor. The PIIs were prepared by the ring-opening polyaddition of the dianhydrides pyromellitic dianhydride, biphenyltetracarboxylic dianhydride and 4, 4′-hexafluoropropylidenedi(phthalic anhydride) with the diamines 2, 2′-dimethylbenzidine and 2, 2′-bis(trifluoromethyl)benzidine, followed by treatment with trifluoroacetic anhydride/triethylamine or dicyclohexylcarbodiimide in N;N-dimethylacetamide. The PIIs were soluble in a wide range of solvents including dipolar aprotic solvents, cyclohexanone and tetrahydrofuran at room temperature, and easy to convert to corresponding PIs by high thermal treatment. The resulting PIs showed low dielectric constants of less than 3 at 1 MHz as well as low CTEs. Furthermore, during the isomerization reaction, migration of copper in the PI film was hardly observed.

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Kinematic and Polarimetric Radar Observations of the 10 May 2010, Moore–Choctaw, Oklahoma, Tornadic Debris Signature

Monthly Weather Review ◽

10.1175/mwr-d-16-0344.1 ◽

2017 ◽

Vol 145 (7) ◽

pp. 2723-2741 ◽

Cited By ~ 6

Author(s):

Casey B. Griffin ◽

David J. Bodine ◽

Robert D. Palmer

Keyword(s):

Three Dimensional ◽

Dielectric Constants ◽

Oklahoma City ◽

Polarimetric Radar ◽

Wind Fields ◽

Irregular Shapes ◽

Wide Range ◽

Wind Retrievals ◽

The University ◽

Differential Reflectivity

Tornadoes are capable of lofting large pieces of debris that present irregular shapes, near-random orientations, and a wide range of dielectric constants to polarimetric radars. The unique polarimetric signature associated with lofted debris is called the tornadic debris signature (TDS). While ties between TDS characteristics and tornado- and storm-scale kinematic processes have been speculated upon or investigated using photogrammetry and single-Doppler analyses, little work has been done to document the three-dimensional wind field associated with the TDS. Data collected by the Oklahoma City, Oklahoma (KTLX), and Norman, Oklahoma (KOUN), WSR-88D S-band radars as well as the University of Oklahoma’s (OU) Advanced Radar Research Center’s Polarimetric Radar for Innovations in Meteorology and Engineering (OU-PRIME) C-band radar are used to construct single- and dual-Doppler analyses of a tornadic supercell that produced an EF4 tornado near the towns of Moore and Choctaw, Oklahoma, on 10 May 2010. This study documents the spatial distribution of polarimetric radar variables and how each variable relates to kinematic fields such as vertical velocity and vertical vorticity. Special consideration is given to polarimetric signatures associated with subvortices within the tornado. An observation of negative differential reflectivity ([Formula: see text]) at the periphery of tornado subvortices is presented and discussed. Finally, dual-Doppler wind retrievals are compared to single-Doppler axisymmetric wind fields to illustrate the merits of each method.

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