THE ADMITTANCE OF A LINEAR ANTENNA IN A UNIAXIAL MEDIUM

1965 ◽  
Vol 43 (12) ◽  
pp. 2276-2309 ◽  
Author(s):  
R. A. Hurd
Keyword(s):  
Integral Equation ◽  
Dielectric Constant ◽  
Relative Permittivity ◽  
Relative Dielectric Constant ◽  
Numerical Results ◽  
Permittivity Tensor ◽  
Linear Antenna ◽  
Isotropic Region

The admittance of a thin, long linear antenna embedded in a uniaxial medium and inclined at an angle θ to the medium's axis is calculated by solving an integral equation. It is shown that the admittance is roughly the same as for an isotropic region with a suitably modified relative dielectric constant given by Keff = √[K(sin2θ K3 + cos2θ K)], where K and K3 are the components of the relative permittivity tensor. Some numerical results are presented.

Effect Of Moisture On The Physical Properties Of Polyimide Films

1991 ◽  
Vol 227 ◽  
Author(s):  
Rajeevi Subramanian ◽  
Michael T. Pottiger ◽  
Jacqueline H. Morris ◽  
Joseph P. Curilla
Keyword(s):  
Dielectric Constant ◽  
Steady State ◽  
Electrical Properties ◽  
Relative Humidity ◽  
Quartz Crystal ◽  
Moisture Absorption ◽  
Relative Dielectric Constant ◽  
Moisture Uptake ◽  
Polyimide Films ◽  
Effect Of Moisture

ABSTRACTMoisture absorption and its effect on electrical properties were measured for several polyimides. A Quartz Crystal Microbalance (QCM) was used to investigate the moisture absorption in BPDA/PPD, PMDA/ODA, and BTDA//ODA/MPD polyimides. The steady-state moisture uptake in polyimides as a function of relative humidity (RH) was determined by exposing film samples to successively higher RH values ranging from 10 to 85% at 25°C. The isothermal moisture absorption as a function of percent RH was found to be nearly linear for all of the polyimides studied. The effect of moisture on the electrical properties of a BPDA/PPD polyimide was also investigated. The relative dielectric constant at 25 °C was found to be a linear function of the moisture absorbed.

The Research on the Piezoelectric and Dielectric Properties of Bi0.5(Nak)0.5-BaTiO3 Lead-Free Ceramics

2014 ◽  
Vol 1035 ◽  
pp. 422-425
Author(s):  
Jian Yong Guo ◽  
Tao Sheng Zhou ◽  
Ji Hong Liao
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Perovskite Structure ◽  
Relative Dielectric Constant ◽  
Lead Free ◽  
Reactive Sintering ◽  
Lead Free Ceramics ◽  
Xrd Patterns ◽  
Sintering Method

The Bi0.5(Na1-xKx)0.5-yBaTiO3(BNK-BT) lead-free ceramics have been prepared by the solild reactive sintering method. XRD patterns show the BNK-BT ceramics had a perovskite structure. Piezoelectric and dielectric properties of the ceramics also have been studied. The results show that the samples had the best piezoelectric and dielectric properties when x=0.20, y=0.10. And the maximum of d33is 149 pC/N, while the relative dielectric constant is 1087.

Influence of the Waterline Integral on the Solution of the Frequency-Domain Forward-Speed Radiation-Diffraction Problem of a Ship Advancing in Waves

2014 ◽  
Author(s):  
D. C. Hong ◽  
S. Y. Hong ◽  
G. J. Lee ◽  
M. S. Shin
Keyword(s):  
Integral Equation ◽  
Free Surface ◽  
Green Function ◽  
Frequency Domain ◽  
Surface Condition ◽  
Numerical Results ◽  
Forward Speed ◽  
Line Integral ◽  
Free Surface Condition ◽  
Surface Green Function

The radiation-diffraction potential of a ship advancing in waves is studied using the three-dimensional frequency-domain forward-speed free-surface Green function (Brard 1948) and the forward-speed Green integral equation (Hong 2000). Numerical solutions are obtained by making use of a second-order inner collocation boundary element method which makes it possible to take account of the line integral along the waterline in a rigorous manner (Hong et al. 2008). The present forward-speed Green integral equation includes not only the usual free surface condition for the potential but also the adjoint free surface condition for the forward-speed free-surface Green function as indicated by Brard (1972). Comparison of the present numerical results of the heave-heave wave damping coefficients and the experimental results for the Wigley ship models I, II and III (Journee 1992) has been presented. These coefficients are compared with those calculated without taking into account of the line integral along the waterline in order to show the forward speed effect represented by the waterline integral when it is properly included in the free-surface Green integral equation. Comparison of the present numerical results and the equivalent time-domain results (Hong et al. 2013) has also been presented.

The Processing and Properties of Multilayer Interconnection Structures Using Thermoset Films Derived from Bisbenzocyclobutene.

1989 ◽  
Vol 154 ◽  
Author(s):  
P. H. Townsend ◽  
D. C. Burdeaux ◽  
S. F. Hahn ◽  
M. Thomsen ◽  
J. N. Carr
Keyword(s):  
Dielectric Constant ◽  
Thermal Cycling ◽  
Relative Dielectric Constant ◽  
Electrical Characteristics ◽  
Processing Conditions ◽  
Dielectric Layers ◽  
Significant Change

AbstractMultilayer interconnection structures incorporating a novel polymeric dielectric derived from a bis-benzocyclobutene(bis-BCB) monomer have been fabricated. This paper discusses the processing conditions for the construction of these circuits and describes electrical characteristics of the dielectric layers. The relative dielectric constant of the BCB film was 2.7. Thermal cycling produced no significant change in the conductance of three level metal via chains through two layers of the polymer.

scholarly journals Experimental Study on the Icing Dielectric Constant for the Capacitive Icing Sensor

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3325
Author(s):  
Yongcan Zhu ◽  
Xinbo Huang ◽  
Yi Tian ◽  
Chao Ji ◽  
Wen Cao ◽  
...  
Keyword(s):  
Experimental Study ◽  
Dielectric Constant ◽  
Test Temperature ◽  
Reference Value ◽  
Relative Dielectric Constant ◽  
Capacitive Sensor ◽  
Fundamental Parameters ◽  
Detection Technology ◽  
Capacitive Method ◽  
Characteristic Values

The capacitive method is considered to be a suitable icing-detection technology, but the lack of fundamental parameters restricts the development of icing-detection sensors. In this paper, an artificial icing laboratory, a capacitive sensor, and some simulation conductors have been designed for obtaining the artificial icing samples. Subsequently, the same characteristic values of artificial icing have been measured by an LCR device, under a selected frequency. This research found that the value of the icing dielectric constant closely correlated with its density, internal sublayer, and the test temperature. Finally, a fitting formula has been presented for calculating the relative dielectric constant, which may provide some important reference value for the design of icing-detection sensors.

Rods falling near a vertical wall

1977 ◽  
Vol 83 (2) ◽  
pp. 273-287 ◽  
Author(s):  
W. B. Russel ◽  
E. J. Hinch ◽  
L. G. Leal ◽  
G. Tieffenbruck
Keyword(s):  
Integral Equation ◽  
Viscous Fluid ◽  
Numerical Solution ◽  
Vertical Wall ◽  
Numerical Results ◽  
Slender Body ◽  
Asymptotic Results ◽  
Slender Body Theory ◽  
Friction Coefficients ◽  
Body Theory

As an inclined rod sediments in an unbounded viscous fluid it will drift horizontally but will not rotate. When it approaches a vertical wall, the rod rotates and so turns away from the wall. Illustrative experiments and a slender-body theory of this phenomenon are presented. In an incidental study the friction coefficients for an isolated rod are found by numerical solution of the slender-body integral equation. These friction coefficients are compared with the asymptotic results of Batchelor (1970) and the numerical results of Youngren ' Acrivos (1975), who did not make a slender-body approximation.

Analysis of the Characteristics on Dielectric Barrier Discharges Depending on the Relative Permittivity and Frequency

2018 ◽  
Vol 875 ◽  
pp. 113-116 ◽  
Author(s):  
Don Kyu Lee
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Relative Permittivity ◽  
Discharge Voltage ◽  
Frequency Region ◽  
Dielectric Barrier Discharges ◽  
Dielectric Barrier ◽  
Dielectric Layers ◽  
Green Sheet ◽  
Barrier Discharges

Various studies are being conducted on the application of DBD (Dielectric barrier discharges). The internal dielectric has a very important characteristic on DBD, thus we analyze of the characteristics on dielectric barrier discharges depending on the relative permittivity and frequency. Through simulation, the discharge voltage was calculated based on relative permittivity and frequency of real used dielectrics (Green sheet, Down dielectric, white dielectric). We investigate that increased relative permittivity and fast frequency occur the decrease of the firing voltage. Also, we investigate the frequency dependence of the dielectric constant and dielectric loss of dielectric layers measured at a frequency region of 100Hz to 10MHz. In a condition of drive within 1MHz, with regard to the change of real and imaginary part according to frequency, it has quite stable dielectric constant in the condition of drive within 1MHz.

scholarly journals Análisis cristalográfico, morfológico, eléctrico, óptico y magnético del nuevo material Dy2BiFeO6

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Jairo Roa-Rojas
Keyword(s):  
Dielectric Constant ◽  
Energy Gap ◽  
Magnetic Hysteresis ◽  
Magnetic Ordering ◽  
Relative Dielectric Constant ◽  
Double Perovskite ◽  
Crystallographic Analysis ◽  
Weiss Temperature ◽  
Constant E ◽  
Diffraction Patterns

We report structural analysis, surface morphology, magnetic ordering, dielectric response, optical feature and the electronic structure of the Dy2BiFeO6 novel complex perovskite. The samples were produced by the standard solid-state reaction recipe. Crystallographic analysis was performed by Rietveld refinement of experimental X-ray diffraction patterns. Results show that this material crystallizes in a perovskite with orthorhombic structure, which corresponds to the Pnma (#62) space group. From the Curie-Weiss fitting on the curve of susceptibility as a function of temperature we establish that the ordering corresponds to a paramagnetic-antiferromagnetic transition, with a Weiss temperature q=-18,5 K, which is compatible with the behavior of the inverse of susceptibility as a function of temperature, and a Néel temperatura TN=50,8 K. The Curie constant allowed for us to obtain an effective magnetic moment of 15,7 mB. The result of magnetization as a function of the applied field, measured at T=50 K, shows a magnetic hysteresis behavior that corroborate the magnetic ordering present for this temperature value. Measurements of the dielectric constant as a function of applied frequencies at room temperature give as a result a high relative dielectric constant (e=780). The reflectance curve as a function of the wavelength reveals the typical behavior of a double perovskite-like material and permits to obtain the energy gap 2,74 eV, which is characteristic of a semiconductor material.

Kinetic Study of Portland Cement Hydration with Ground Penetrating Radar

2013 ◽  
Vol 539 ◽  
pp. 25-29
Author(s):  
Wei Chen ◽  
Pei Liang Shen ◽  
Jian Xin Lu ◽  
Wan Ru Zhang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Ground Penetrating Radar ◽  
Cement Hydration ◽  
Relative Dielectric Constant ◽  
Gradual Decline ◽  
Hardening Process ◽  
Ground Penetrating ◽  
Kinetics Of ◽  
Portland Cement Hydration

The variations of dielectric constant and the amplitude of reflected EM wave of concrete during the first 3 days are measured with Ground Penetrating Radar (GPR) at 20 oC. The amplitude decreases sharply after mixing with water, and then increases till a stabilized stage, followed by a gradual decline. The relative dielectric constant decreases with increasing hydrating time. The results show that the dielectric properties of concrete can be used as an effective way of studying the kinetics of concrete setting and hardening process at early ages.

Wave Forces on Large Objects in the Sea

1971 ◽  
Vol 15 (02) ◽  
pp. 115-124
Author(s):  
Jerome H. Milgram ◽  
John E. Halkyard
Keyword(s):  
Integral Equation ◽  
Vertical Surface ◽  
Numerical Results ◽  
Successive Approximations ◽  
Wave Forces ◽  
Algebraic Equations ◽  
Stationary Objects ◽  
Points Of View ◽  
Axisymmetric Bodies ◽  
Direct Calculations

Three methods of finding wave forces on large, rigid axisymmetric stationary objects in the sea are examined. The problem is formulated in terms of an integral equation and the three methods are successive approximations, direct calculations by means of simultaneous algebraic equations, and use of Haskind's relations. The latter method is included as it offers a large saving of computational efforts for axisymmetric bodies. The applicability of the methods is studied from both the theoretical and applied points of view. Numerical results are given for submerged and floating spheres and for shapes comprising a vertical surface-piercing cylinder atop a sphere.

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