Ondes électromagnétiques de surface de type HE11

1988 ◽  
Vol 66 (3) ◽  
pp. 233-237
Author(s):  
G. Zepp ◽  
A. Wick ◽  
A. Boubakra ◽  
G. Fabre ◽  
G. Ritoux
Keyword(s):  
Phase Shift ◽  
Attenuation Factor ◽  
Finite Conductivity ◽  
Dielectric Losses ◽  
Microwave Propagation ◽  
Cylindrical Conductor ◽  
Analytical Expressions

We have studied the electromagnetic microwave propagation of the HE11 mode on the surface of a cylindrical conductor coated with a dielectric and embedded in a second dielectric. The present study takes into account the finite conductivity of the metal and dielectric losses for the determination of precise analytical expressions of the attenuation factor and phase shift.

Propagation d'une onde électromagnétique à la surface d'un conducteur ou d'un supraconducteur de section circulaire

1981 ◽  
Vol 59 (7) ◽  
pp. 902-913 ◽  
Author(s):  
Georges Fabre ◽  
Alain Wick ◽  
Gérard Zepp
Keyword(s):  
Electromagnetic Wave ◽  
Phase Shift ◽  
Cross Section ◽  
Attenuation Factor ◽  
Circular Cross Section ◽  
Transverse Mode ◽  
Onde Électromagnétique ◽  
Mode Propagation ◽  
Metallic Cylinder ◽  
Analytical Expressions

We are studying the electromagnetic wave (magnetic transverse mode) propagation on the surface of a circular cross section metallic cylinder coated with one or several dielectrics. The method we use allows us to study not only the case of ordinary metals, but also the case of superconductor metals. We determine the precise analytical expressions (for any kind of metal) of characteristic quantities: attenuation factor and phase shift.

Localisation de l'énergie transportée par une onde électromagnétique à la surface d'un conducteur de section circulaire

1982 ◽  
Vol 60 (6) ◽  
pp. 868-876
Author(s):  
Alain Wick ◽  
Gérard Zepp ◽  
Georges Ritoux ◽  
Georges Fabre
Keyword(s):  
Electromagnetic Wave ◽  
Onde Électromagnétique ◽  
Energy Concentration ◽  
Finite Conductivity ◽  
Dielectric Losses ◽  
Cylindrical Conductor

We have been interested in the localization of the energy carried by an electromagnetic wave of the TM type propagated at the surface of a cylindrical conductor coated with two dielectrics. The present study takes into account both the finite conductivity of the metal and dielectric losses. It is shown that it is possible to reconcile an excellent energy concentration with a very low attenuation of the wave.

Diagnostics of the location of damage to tubing oil well pipes

2019 ◽  
Vol 5 (4) ◽  
pp. 115-128
Author(s):  
Timur A. Ishmuratov ◽  
Rif G. Sultanov ◽  
Milyausha N. Khusnutdinova
Keyword(s):  
Fluid Motion ◽  
Oil Well ◽  
General Belief ◽  
Oil Flow ◽  
Specialized Equipment ◽  
Improving Accuracy ◽  
Analytical Expressions ◽  
Technical Measures ◽  
Quick Determination

The study is devoted to the mathematical description of the process of oil outflow in places of leakage of the tubing string, which allows a computer to locate a leakage in the tubing. The authors propose methodology for identifying defects in the tubing and determining the location of the leak. The uniqueness of this methodology lies in quick determination of the place of leakage without the use of specialists, sophisticated and specialized equipment. Mathematical modeling of oil flow in the tubing requires the apparatus of continuum mechanics. It is a general belief that the movement of oil in the pipe flows at low speeds due to its outflow from the hole. Using the general equations of mass and energy balance, the authors have obtained differential equations of fluid motion in a vertical pipe in the process of its outflow from the tubing and in the process of injection. Analytical expressions are the solution to these equations, as they can help in estimating the degree of damage and its location, as well as the feasibility of its eliminating. The results show that an increase in the leakage and injection times leads to improving accuracy of locating damage. Thus, when conducting various geological and technical measures (GTM) at the well, it is possible to assess the presence of leakage and its intensity when deciding on the repair of tubing.

The harmonic and transient electromagnetic response of a thin dipping dike

Geophysics ◽  
1983 ◽  
Vol 48 (7) ◽  
pp. 934-952 ◽  
Author(s):  
P. Weidelt
Keyword(s):  
Formal Solution ◽  
Harmonic Excitation ◽  
Electromagnetic Response ◽  
Approximate Determination ◽  
Finite Conductivity ◽  
Circular Loop ◽  
Decay Modes ◽  
Transient Electromagnetic ◽  
Free Decay

An exact solution is given for the electromagnetic induction in a dipping dike of finite conductivity, represented as a thin half‐sheet in a nonconducting surrounding. The problem is formulated for arbitrary dipole or circular loop [Formula: see text] configurations. The formal solution obtained by the Wiener‐Hopf technique is cast into a rapidly convergent triple integral suitable for an effective numerical treatment. A good agreement is found between numerical results and analog measurements available for harmonic excitation. The transient response is obtained as a superposition of the half‐sheet free‐decay modes and is illustrated by some numerical examples for coincident loops, including a diagram for the approximate determination of conductance and depth of a vertical dike.

Complete determination of polarization state in the hard X-ray region

1991 ◽  
Vol 24 (6) ◽  
pp. 982-986 ◽  
Author(s):  
T. Ishikawa ◽  
K. Hirano ◽  
S. Kikuta
Keyword(s):  
Phase Shift ◽  
Linear Polarization ◽  
Amplitude Ratio ◽  
Polarization State ◽  
Perfect Crystal ◽  
Electric Vector ◽  
X Ray ◽  
Complete Determination ◽  
Unpolarized Radiation

A new method for complete determination of polarization state in the hard X-ray region is described. The system consists of a perfect-crystal phase retarder and a linear polarization analyzer. This method gives not only the amplitude ratio of mutually perpendicular electric vector components and the phase shift between them but also the proportion of unpolarized radiation.

Determination of the Effective Depth for Double-Fiber Fluorometric Sensors

1992 ◽  
Vol 46 (6) ◽  
pp. 919-924 ◽  
Author(s):  
Zhong Yuan Zhu ◽  
M. Cecilia Yappert
Keyword(s):  
Fiber Optic Sensor ◽  
Fluorescence Signal ◽  
Acceptance Angle ◽  
Fiber Sensors ◽  
Sample Depth ◽  
Effective Depth ◽  
Different Diameters ◽  
Semi Empirical ◽  
Analytical Expressions

The relationship between the relative fluorescence signal excited and collected with a double-fiber optic sensor and the sample depth has been investigated. The complexity of the analytical expressions for the relative fluorescence signal and the effective depth was reduced by deriving a set of semi-empirical equations which can be evaluated in a simple fashion. These expressions take into account the configuration of the sensor, i.e., fiber diameter, acceptance angle, and separation between fibers. The expressions were tested with the use of double-fiber sensors with different diameters and separations between fibers. The reduction of the effective depth in solutions with significant absorbance was evaluated.

scholarly journals Analytical Expressions of Hydro-Seismic Forces on Dams

2018 ◽  
Author(s):  
Abdelmadjid Tadjadit ◽  
Boualem Tiliouine
Keyword(s):  
Viscous Fluid ◽  
Linear Combination ◽  
Upstream Face ◽  
Compressible Viscous Fluid ◽  
Natural Modes ◽  
Boundary Method ◽  
Complete Sets ◽  
Seismic Forces ◽  
Analytical Expressions

Analytical expressions for the determination of hydro-seismic forces acting on a rigid dam with irregular upstream face geometry in presence of a compressible viscous fluid are derived through a linear combination of the natural modes of water in the reservoir based on a boundary method making use of complete sets of complex T-functions.Analytical expressions for the determination of hydro-seismic forces acting on a rigid dam with irregular upstream face geometry in presence of a compressible viscous fluid are derived through a linear combination of the natural modes of water in the reservoir based on a boundary method making use of complete sets of complex T-functions. The formulas obtained for distributions of both shear forces and overturning moments are simple, computationally effective and useful for the preliminary design of dams. They show clearly the separate and combined effects of compressibility and viscosity of water. They also have the advantage of being able to cover a wide range of excitation frequencies even beyond the cut-off frequencies of the natural modes of the reservoir. Key results obtained using the proposed analytical expressions of the hydrodynamic forces are validated using numerical and experimental solutions published for some particular cases available in the specialized literature.

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