Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

Sorted by: relevance · author · university · dateNew search

You searched for subject:(quarter wave resonance). Showing records 1 – 2 of 2 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


Luleå University of Technology

1. Karlsson, Christian A. M. Sensus Aquae in Ferrum ac Air : Karakterisering av elektriska egenskaper hos ett fuktmätnings system.

Degree: 2011, Luleå University of Technology

Fast precise moisture measurement in mineral process plants, has long been a difficult problem. In this master thesis a foundation for a new way of measurement using transmission line theory, is laid out. Macroscopic electro-magnetic properties of the measured sample can be linked to those of the individual constituents of the sample. Thus one is believed to be able to do a precise estimate of the amount of moisture in a sample. In our case the samples are moist magnetite concentrate. The characterization of sample macroscopic electro-magnetic properties is done by using a coaxial cell, performing frequency spectra measurement. In this master thesis, the electrical behavior that links the measured data to the macroscopic electro-magnetic properties is examined. It exists two setups, one inductive and one capacitive. The DC resistivity of the moist magnetite concentrate is determined and some interesting phenomena, suggested to be self potential were discovered. This phenomenon is in general known from geochemistry of mineral rich clays. This made the measurements of resistivity tricky to perform, some measurements were achieved and a new relation between moisture of the moist magnetite concentrate and resistivity is presented. Studies have been performed on the history of attempts of solving this problem, as well as current relevant research. Reference samples have been prepared in a geotechnical laboratory. Impedance frequency behavior of the measurement equipment is measured and presented, with different curves for different moisture content. From these measurements it is obvious that the moisture affects the impedance of the measurement equipment and thus it is possible to use this method to measure moisture content, if one can determine the electrical model which describes the measurement system. A few equivalent circuits of transmission lines have been discussed, and one was chosen to represent the purely coaxial part of the coaxial cell. Other parts have been modeled with other elements of AC theory. A new electrical model for the coaxial probe is proposed, based on LC resonances. Some Comsol FEM simulations have been performed on the coaxial cell, as well as on electric property sensors. Ideas to designs of electrical sensors are discussed. It is mainly the geometry which has been investigated. First it was proposed that a phenomenon of resonance occurs at the interface of the bottom and coaxial part of the cell, LC resonance. The resonance effect has later been investigated and identified as quarter wavelength resonance, due to the length of the measurement cell and change of wave velocity due to wave propagation in MUT. Simulations of proposed circuit equivalents in Orcad with PSpice have given some correlation with measured data for dry and non-conducting samples. There is still work to be done, to complete an accurate mathematical model of the system.

Validerat; 20110824 (anonymous)

Subjects/Keywords: Technology; Teknik; measurement; moisture; RF; electric permittivity; magnetic permeability; broad-band spectroscopy; frequency spectra; magnetite concentrate; Fe3O4; resistivity; equivalent circuits; coaxial cell; quarter wave resonance

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Karlsson, C. A. M. (2011). Sensus Aquae in Ferrum ac Air : Karakterisering av elektriska egenskaper hos ett fuktmätnings system. (Thesis). Luleå University of Technology. Retrieved from http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-54848

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Karlsson, Christian A M. “Sensus Aquae in Ferrum ac Air : Karakterisering av elektriska egenskaper hos ett fuktmätnings system.” 2011. Thesis, Luleå University of Technology. Accessed January 16, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-54848.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Karlsson, Christian A M. “Sensus Aquae in Ferrum ac Air : Karakterisering av elektriska egenskaper hos ett fuktmätnings system.” 2011. Web. 16 Jan 2021.

Vancouver:

Karlsson CAM. Sensus Aquae in Ferrum ac Air : Karakterisering av elektriska egenskaper hos ett fuktmätnings system. [Internet] [Thesis]. Luleå University of Technology; 2011. [cited 2021 Jan 16]. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-54848.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Karlsson CAM. Sensus Aquae in Ferrum ac Air : Karakterisering av elektriska egenskaper hos ett fuktmätnings system. [Thesis]. Luleå University of Technology; 2011. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-54848

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Brno University of Technology

2. Šmarda, Marek. Miniaturní anténa pro mobilní aplikace: Miniature antenna for mobile applications.

Degree: 2019, Brno University of Technology

This work deals with the most famous constructions of planar antennas. The work analyses selected methods of connecting planar antennas' charging with the possibility of impedance adaptation. An important part of the work consists of description of techniques for increasing bandwidth and conversely techniques for reducing the dimensions which are important for the design of planar antennas for mobile devices. The antennas were designed by means of theoretical basis and their properties were examined in the electromagnetic field simulator. The selected antenna model was constructed and its parameters were measured experimentally. The matching circuit for the antenna to tune it to different resonant frequencies was designed and constructed. Advisors/Committee Members: Pokorný, Michal (advisor), Švanda,, Milan (referee).

Subjects/Keywords: Flíčková anténa; štěrbinová anténa; PIFA; fraktální anténa; čtvrtvlnná rezonance; zkratovací stěna; zkratovací pin; permitivita; zatěžovací kapacita; parazitní rezonátor; přizpůsobovací obvod; přeladění kmitočtu; mikropáskové vedení; koplanární vedení; činitel odrazu; směrová charakteristika.; Patch antenna; slot antenna; PIFA; fractal antenna; quarter wave resonance; shorting wall; shorting pin; permittivity; load capacitance; parasitic resonator; matching circuit; tuning frequency; microstrip line; coplanar waveguide; reflection coefficient; directional characteristic.

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Šmarda, M. (2019). Miniaturní anténa pro mobilní aplikace: Miniature antenna for mobile applications. (Thesis). Brno University of Technology. Retrieved from http://hdl.handle.net/11012/27360

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Šmarda, Marek. “Miniaturní anténa pro mobilní aplikace: Miniature antenna for mobile applications.” 2019. Thesis, Brno University of Technology. Accessed January 16, 2021. http://hdl.handle.net/11012/27360.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Šmarda, Marek. “Miniaturní anténa pro mobilní aplikace: Miniature antenna for mobile applications.” 2019. Web. 16 Jan 2021.

Vancouver:

Šmarda M. Miniaturní anténa pro mobilní aplikace: Miniature antenna for mobile applications. [Internet] [Thesis]. Brno University of Technology; 2019. [cited 2021 Jan 16]. Available from: http://hdl.handle.net/11012/27360.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Šmarda M. Miniaturní anténa pro mobilní aplikace: Miniature antenna for mobile applications. [Thesis]. Brno University of Technology; 2019. Available from: http://hdl.handle.net/11012/27360

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.