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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Analysis and design of enclosures for electromagnetic suscepibility measurements over a wide frequency range (20MHz-30GHz)

Mishra, Shantnu R. January 1982 (has links)
Absorber lined chambers (ALC's) or anechoic type enclosures operated under degraded conditions are introduced. Results of measurements inside scaled model ALC's are reported to demonstrate the feasibility of their use as environment simulators for electromagnetic susceptibility (E.M.S.) measurements over an extremely wide frequency range. The hardware and software of the automated microprocessor based facility developed for the measurement of amplitude and phase of e.m. fields in a volume of space, are described. / A geometrical optic (GO) technique and an 'idealized' material model to predict ALC fields is developed. Computed results are presented for a range of cases including some whose measurement would not be practicable. Using measured and computed data, criteria and guidelines for economic ALC design are established. / An experimental investigation of near-region scattering by various absorbers was carried out to seek the possibility of improving the material model with the objective of improving field prediction using the geometrical theory of diffraction (GTD).
2

Analysis and design of enclosures for electromagnetic suscepibility measurements over a wide frequency range (20MHz-30GHz)

Mishra, Shantnu R. January 1982 (has links)
No description available.
3

Une combinaison des methodes electromagnetiques a cadres horizontaux "Slingram" et Turam.

Lavoie, Clermont January 1972 (has links)
No description available.
4

The measurement of mineral electrode potentials

Ingram, John Charavelle. January 1913 (has links) (PDF)
Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1913. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed April 27, 2009) Includes bibliographical references.
5

Une combinaison des methodes electromagnetiques a cadres horizontaux "Slingram" et Turam.

Lavoie, Clermont January 1972 (has links)
No description available.
6

Pore-scale petrophysical models for the simulation and combined interpretation of nuclear magnetic resonance and wide-band electromagnetic measurements of saturated rocks

Toumelin, Emmanuel. January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.
7

Algorithms for numerical modeling and inversion of multi-phase fluid flow and electromagnetic measurements

Alpak, Faruk Omer. Torres-Verdín, Carlos, Sepehrnoori, Kamy, January 2005 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisors: Carlos Torres-Verdín and Kamy Sepehrnoori. Vita. Includes bibliographical references.
8

Direct measurement of parallel plate heat sink bypass flow

Crockett, Dean D., January 2006 (has links) (PDF)
Thesis (M.S. in mechanical engineering)--Washington State University, December 2006. / Includes bibliographical references (p. 49).
9

Implementation of a reverberation chamber for electro-magnetic compatibility measurements

Naftali, Verena Kashikuka January 2017 (has links)
Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2017. / This research project focuses on the implementation of a Reverberation Chamber (RC) by the transformation of an existing electromagnetically shielded room. The reverberation chamber is a kind of shielded room designed to create a statistically random internal electromagnetic environment. The reverberating environment makes it possible to obtain high field strengths from a relatively low input power. The electric fields in the chamber have to be stirred to achieve a statistically uniform field. The first part of this thesis presents an overview of reverberation chamber principles and preliminary calculations are done: the lowest usable frequency is estimated to be close to 300 MHz from empirical criteria. Modelling of the statistical environment is then presented, where electromagnetic quantities are characterised by probability density functions (Gaussian, Rayleigh and exponential); correlation issues are also presented. Measurements are performed in the frequency range of 800 MHz – 4 GHz, dictated by the antennas available for this research study. An investigation of cable losses is conducted, followed by a discussion on measurement accuracy. Mechanical stirrers are designed and manufactured. Electromechanical components are selected based on the literature study. Measurements are obtained through an automated setup using MATLAB®. To verify that the RC, with its in-house designed mechanical stirrers, is well-operated, the stirring ratio is experimentally determined. After this first test, an exhaustive investigation of probability density functions is conducted, taking into account correlation issues. Measurements show that the quality factor of the chamber is close to 2000 at 3 GHz, and that 60 independent stirrer positions at 4 GHz can be used for statistical analyses. Finally, the uniformity test is performed with an improved accuracy using frequency stirring. In conclusion, the CPUT RC passes the validation procedure according to the IEC 61000-4-21 standard by generating the required field uniformity within the accepted uncertainty level.
10

Borehole electromagnetic prospecting for weak conductors

Theodoridis, John Apostolis, 1972- January 2004 (has links)
Abstract not available

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