subject:(coaxial cell)

Oklahoma State University

1. Duvall, James. Issues Pertaining to Dielectric Assessment of Soil Moisture in a Coaxial Cell.

Degree: School of Electrical & Computer Engineering, 2010, Oklahoma State University

► The study considered a pre-existing coaxial cell design and attempted to improve upon the accuracy of the coaxial cell as a measurement device. The cell… (more)

Subjects/Keywords: coaxial cell; dielectric; soil moisture

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APA (6^th Edition):

Duvall, J. (2010). Issues Pertaining to Dielectric Assessment of Soil Moisture in a Coaxial Cell. (Thesis). Oklahoma State University. Retrieved from http://hdl.handle.net/11244/10198

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

Chicago Manual of Style (16^th Edition):

Duvall, James. “Issues Pertaining to Dielectric Assessment of Soil Moisture in a Coaxial Cell.” 2010. Thesis, Oklahoma State University. Accessed January 23, 2021. http://hdl.handle.net/11244/10198.

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

MLA Handbook (7^th Edition):

Duvall, James. “Issues Pertaining to Dielectric Assessment of Soil Moisture in a Coaxial Cell.” 2010. Web. 23 Jan 2021.

Vancouver:

Duvall J. Issues Pertaining to Dielectric Assessment of Soil Moisture in a Coaxial Cell. [Internet] [Thesis]. Oklahoma State University; 2010. [cited 2021 Jan 23]. Available from: http://hdl.handle.net/11244/10198.

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

Council of Science Editors:

Duvall J. Issues Pertaining to Dielectric Assessment of Soil Moisture in a Coaxial Cell. [Thesis]. Oklahoma State University; 2010. Available from: http://hdl.handle.net/11244/10198

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

University of Queensland

2. Bittner, Tilman. On the transient process of contact erosion (instabilities during granular erosion).

Degree: School of Civil Engineering, 2019, University of Queensland

URL: http://espace.library.uq.edu.au/view/UQ:0

► Internal erosion is one of the major threats for water retaining structures like embankment dams or levees. Numerous design criteria were developed in the last… (more)

▼ Internal erosion is one of the major threats for water retaining structures like embankment dams or levees. Numerous design criteria were developed in the last decades for this reason. As the main concern of the geotechnical engineer is to prevent erosion, it is not astonishing that a vast majority of the criteria are focussed on the onset or initiation of erosion, or more precise, to avoid it. However, many existing structures have already experienced the one or other event of internal erosion. Thus, it is beneficial to understand not only the initiation, but also the progression of the erosion process. This process is though still not completely understood.Among the different types of internal erosion, contact erosion is characterised by two soils (base and filter) of different grain size distributions (PSD) forming an interface to each other. The erosion process is triggered by a water flow, which can be either parallel or perpendicular to the interface. The latter configuration is sometimes referred to as filtration and is in the focus of this research. If erosion occurs, base particles are transported into the pores of the filter by a water flow, forming a mixture zone with a lower porosity and permeability. For a better understanding of the contact erosion process, the formation of this zone must be understood. Two main aspects can be identified: The behaviour of the base material under the hydraulic load and the arrangement of the particles in the mixture zone, which is expressed in the porosity as a macroscopic parameter.Porosity alterations during erosion tests can be determined in different ways. These are among others: Direct observations of changes in layer heights, Computed Tomography (CT) and radiometric methods. Electromagnetic methods take advantage of the different dielectric permittivity of the solid, liquid and gaseous phases of a soil, which interact with an electric pulse travelling along a sensor surrounded by the material under test. An average value can be obtained with Time Domain Reflectometry (TDR). With an inversion algorithm, the spatial distribution of the parameter of interest, e.g. porosity or moisture, can be computed out of the TDR-trace. This method is called Spatial TDR (STDR), which was chosen for this research work. The three step inverse model was established and refined for this setup and its accuracy proven in calibration and verification measurements.In order to study the behaviour of the base material alone under hydraulic load, a test stand called Fluidisation Setup was developed. Different base materials were tested under increasing hydraulic potentials up to the point of hydraulic heave. The inner stress conditions during this tests were checked with vane-shear-tests. A clear correlation of shear resistance and hydraulic load was found. Additionally, the dielectric permittivity of the material was measured up to high porosities obtained during the fluidisation.A Coaxial Erosion Cell (CEC) was developed to act as a sensor by itself for the erosion tests. The coaxial…

Subjects/Keywords: Contact erosion; Initiation and progression of erosion; Porosity measurements; Spatial TDR; Coaxial cell; 0404 Geophysics; 0905 Civil Engineering

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APA (6^th Edition):

Bittner, T. (2019). On the transient process of contact erosion (instabilities during granular erosion). (Thesis). University of Queensland. Retrieved from http://espace.library.uq.edu.au/view/UQ:0

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

Chicago Manual of Style (16^th Edition):

Bittner, Tilman. “On the transient process of contact erosion (instabilities during granular erosion).” 2019. Thesis, University of Queensland. Accessed January 23, 2021. http://espace.library.uq.edu.au/view/UQ:0.

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

MLA Handbook (7^th Edition):

Bittner, Tilman. “On the transient process of contact erosion (instabilities during granular erosion).” 2019. Web. 23 Jan 2021.

Vancouver:

Bittner T. On the transient process of contact erosion (instabilities during granular erosion). [Internet] [Thesis]. University of Queensland; 2019. [cited 2021 Jan 23]. Available from: http://espace.library.uq.edu.au/view/UQ:0.

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

Council of Science Editors:

Bittner T. On the transient process of contact erosion (instabilities during granular erosion). [Thesis]. University of Queensland; 2019. Available from: http://espace.library.uq.edu.au/view/UQ:0

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

Luleå University of Technology

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

Degree: 2011, Luleå University of Technology

URL: http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-54848

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Fast precise moisture measurement in mineral process plants, has long been a difficult problem. In this master thesis a foundation for a new way… (more)

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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

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

APA (6^th 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 (16^th 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 23, 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 (7^th Edition):

Karlsson, Christian A M. “Sensus Aquae in Ferrum ac Air : Karakterisering av elektriska egenskaper hos ett fuktmätnings system.” 2011. Web. 23 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 23]. 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

INP Toulouse

4. Wang, Jingyi. Contribution to the characterization of stratified structures : electromagnetic analysis of a coaxial cell and a microstrip line : Contribution à la caractérisation des structures stratifiées : analyse électromagnétique d'une cellule coaxiale et une ligne microruban.

Degree: Docteur es, Electromagnétisme et Systèmes Haute Fréquence, 2018, INP Toulouse

URL: http://www.theses.fr/2018INPT0004

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L’objectif de cette étude est le développement des logiciels de modélisation électromagnétique spécifique aux cellules de caractérisation micro-ondes des matériaux. Ce développement s’appuiesur des méthodes… (more)

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L’objectif de cette étude est le développement des logiciels de modélisation électromagnétique spécifique aux cellules de caractérisation micro-ondes des matériaux. Ce développement s’appuiesur des méthodes numériques alternatives à celle des éléments finis largement utilisés dans des logiciels de commerce. Pour le besoin d’extraction des propriétés des matériaux par des méthodes de modélisation inverse, la recherche en l’efficacité numérique de l’analyse directe est le point central de cette étude. Les cellules de caractérisation ciblées dans ce travail concernent une cellule coaxiale et une cellule en ligne planaire. La présence d’un matériau inconnu est modélisée par une structure de transmission hétérogène stratifiée. L’application de la méthode de l’opérateur transverse (TOM) sur la cellule coaxiale multicouche a permis la détermination de la constante de propagation du mode fondamental, la répartition des champs électromagnétique, et les caractéristiques des modes d’ordre supérieurs pour le besoin de la caractérisation des discontinuités entre ligne vide et ligne chargée. Dans le cas de la cellule en microruban l’utilisation de la méthode de résonance transverse modifiée (MTRM) a permis la détermination des caractéristiques des modes d’ordre fondamental et supérieur. Chaque cellule étant constitué de plusieurs sections différentes, la matrice S de l’ensemble sera déterminée par l’utilisation de plusieurs méthodes modales : méthode de raccordement modal (« Mode Matching »)et méthode variationnelle multimodale (MVM). Les codes d’analyse directe sont couplés avec plusieurs programmes d’optimisation pour constituer les logiciels d’extraction des paramètres matériaux. Ceux-ci sont appliqués à des échantillons de matériaux sous forme de cylindre trouée par la cellule coaxiale, ou de plaquette rectangulaire mince par la cellule microruban. Des résultats d’extraction large bande ont été obtenus ; des valeurs sont comparables avec ceux publiés. Aussi bien des diélectriques à fortes pertes que des matéraux nano structurés ont fait l’objet des études par nos méthodes

The objective of this dissertation is the development of electromagnetic modelling software specific to the cells of microwave material characterization. This development is based on numerical methods that are alternative to finite element method which is widely used in commercial software. For the need to extract the properties of materials by inverse modelling methods, research into the numerical efficiency of direct analysis is the focus in this thesis. The characterization targeted cells in this work concern a coaxial cell and a planar line. The presence of an unknown material is modelled by a stratified heterogeneous transmission structure. The application of the transverse operator method (TOM) on the multi-layered coaxial cell allowed the determination of the propagation constant of fundamental mode and its corresponding field distribution of the electromagnetic fields, and the characteristics of higher-order modes for the need of the…

Advisors/Committee Members: Tao, Junwu (thesis director).

Subjects/Keywords: Méthode numérique; Procédure d'optimisation; Cellule coaxiale; Matériau diélectrique à forte perte; Microruban; Matériau de nanostructure; Numerical method; Optimization procedure; Coaxial cell; High-loss dielectric material; Microstrip line; Nanostructure material

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

APA (6^th Edition):

Wang, J. (2018). Contribution to the characterization of stratified structures : electromagnetic analysis of a coaxial cell and a microstrip line : Contribution à la caractérisation des structures stratifiées : analyse électromagnétique d'une cellule coaxiale et une ligne microruban. (Doctoral Dissertation). INP Toulouse. Retrieved from http://www.theses.fr/2018INPT0004

Chicago Manual of Style (16^th Edition):

Wang, Jingyi. “Contribution to the characterization of stratified structures : electromagnetic analysis of a coaxial cell and a microstrip line : Contribution à la caractérisation des structures stratifiées : analyse électromagnétique d'une cellule coaxiale et une ligne microruban.” 2018. Doctoral Dissertation, INP Toulouse. Accessed January 23, 2021. http://www.theses.fr/2018INPT0004.

MLA Handbook (7^th Edition):

Wang, Jingyi. “Contribution to the characterization of stratified structures : electromagnetic analysis of a coaxial cell and a microstrip line : Contribution à la caractérisation des structures stratifiées : analyse électromagnétique d'une cellule coaxiale et une ligne microruban.” 2018. Web. 23 Jan 2021.

Vancouver:

Wang J. Contribution to the characterization of stratified structures : electromagnetic analysis of a coaxial cell and a microstrip line : Contribution à la caractérisation des structures stratifiées : analyse électromagnétique d'une cellule coaxiale et une ligne microruban. [Internet] [Doctoral dissertation]. INP Toulouse; 2018. [cited 2021 Jan 23]. Available from: http://www.theses.fr/2018INPT0004.

Council of Science Editors:

Wang J. Contribution to the characterization of stratified structures : electromagnetic analysis of a coaxial cell and a microstrip line : Contribution à la caractérisation des structures stratifiées : analyse électromagnétique d'une cellule coaxiale et une ligne microruban. [Doctoral Dissertation]. INP Toulouse; 2018. Available from: http://www.theses.fr/2018INPT0004

INP Toulouse

5. Wu, Li. Contribution to the multi-physics study of porous media heated intermittently by RF energy in a coaxial cell : Contribution à l'étude multi-physique du chauffage de milieux poreux par énergie radiofréquence intermittente dans une cellule coaxiale.

Degree: Docteur es, Micro-ondes, Électromagnétisme et Optoélectronique, 2015, INP Toulouse

URL: http://www.theses.fr/2015INPT0137

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Avec l'explosion économique et démographique, le besoin en matériaux poreux tels que la nourriture, le bois ou la brique connait une croissance telle que leur… (more)

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Avec l'explosion économique et démographique, le besoin en matériaux poreux tels que la nourriture, le bois ou la brique connait une croissance telle que leur commerce est très actif dans le monde entier. La déshydratation des milieux poreux étant l'une des plus importantes et stables méthodes pour leur préservation, il est parfois nécessaire d'utiliser cette méthode pour stocker, transporter et mieux utiliser ces matériaux. Depuis la Seconde Guerre Mondiale, il existe des méthodes de chauffage RF dans bien des domaines. Bien que beaucoup de nouvelles technologies de chauffage sont devenues extrêmement importantes du point de vue commercial et très largement utilisées, le chauffage RF est préféré aux autres moyens de chauffage pour plusieurs raisons: 1) le résultat est plus rapide, nécessitant un moindre temps pour atteindre la température désirée; 2) le chauffage radiofréquence peut être spatialement plus uniforme que les méthodes conventionnelles de chauffage; 3) le chauffage par radiofréquences peut être allumé ou éteint instantanément; 4) il est plus efficace pour un grand volume de nourriture; 5) l'investissement nécessaire est moindre, etc. Cependant on trouve très peu d'information sur le chauffage radiofréquence pour la déshydratation des matériaux poreux dans la littérature. Par conséquent, il est intéressant d'étudier les interactions entre les radiofréquences et les milieux poreux. Afin d'améliorer le taux d'énergie radiofréquence utilisé, cette thèse propose une cavité coaxiale pour étudier le cycle de chauffage radiofréquence d'une pomme de terre dans différents états : solide, liquide et gazeux. Dans un premier temps nous avons étudié les mécanismes de transport de masse et de chaleur dans le milieu poreux sans radiofréquence sur le modèle d'une brique 1D à l'aide d'un code Matlab. Les résultats de simulation ont été comparés qualitativement avec ceux du papier de référence. A partir de ce modèle, nous avons construit et simulé un modèle 2D axisymétrique avec le chauffage radiofréquence périodique d'une pomme de terre. L’équation de Landau et Lifshitz, Looyenga a été utilisées pour prédire le changement de permittivité effective dans la simulation car il est difficile d'obtenir une donnée précise pour un milieu poreux. La salinité de l'échantillon chauffé (qui est une caractéristique très importante) a été estimée. Les effets de différentes périodes, hauteurs de l'échantillon et puissances de la distribution en température ont été étudiés et analysés. Nous avons également mené des expériences similaires pour mesurer les changements de température durant le processus de chauffage. Tous les résultats de simulations sont comparés qualitativement avec les résultats mesurés. De même nous avons effectué des analyses de sensibilité et en avons conclu quelques suggestions concernant l'amélioration des effets du chauffage. A partir de ces suggestions, nous avons proposé un nouveau modèle de chauffage radiofréquence afin de s'affranchir des défauts du modèle précédent.

With the rapid growth of economic and…

Advisors/Committee Members: Tao, Junwu (thesis director), Lacout, Jean-Louis (thesis director).

Subjects/Keywords: Chauffage radiofréquence par intermittence; Milieux poreux; Permittivité effective; Équation de Landau et Lifshitz, Looyenga; Salinité; Cellule coaxiale; RF intermittently heating; Porous media; Effective permittivity; Landau and Lifshitz, Looyenga equation; Salinity; Coaxial cell

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

APA (6^th Edition):

Wu, L. (2015). Contribution to the multi-physics study of porous media heated intermittently by RF energy in a coaxial cell : Contribution à l'étude multi-physique du chauffage de milieux poreux par énergie radiofréquence intermittente dans une cellule coaxiale. (Doctoral Dissertation). INP Toulouse. Retrieved from http://www.theses.fr/2015INPT0137

Chicago Manual of Style (16^th Edition):

Wu, Li. “Contribution to the multi-physics study of porous media heated intermittently by RF energy in a coaxial cell : Contribution à l'étude multi-physique du chauffage de milieux poreux par énergie radiofréquence intermittente dans une cellule coaxiale.” 2015. Doctoral Dissertation, INP Toulouse. Accessed January 23, 2021. http://www.theses.fr/2015INPT0137.

MLA Handbook (7^th Edition):

Wu, Li. “Contribution to the multi-physics study of porous media heated intermittently by RF energy in a coaxial cell : Contribution à l'étude multi-physique du chauffage de milieux poreux par énergie radiofréquence intermittente dans une cellule coaxiale.” 2015. Web. 23 Jan 2021.

Vancouver:

Wu L. Contribution to the multi-physics study of porous media heated intermittently by RF energy in a coaxial cell : Contribution à l'étude multi-physique du chauffage de milieux poreux par énergie radiofréquence intermittente dans une cellule coaxiale. [Internet] [Doctoral dissertation]. INP Toulouse; 2015. [cited 2021 Jan 23]. Available from: http://www.theses.fr/2015INPT0137.

Council of Science Editors:

Wu L. Contribution to the multi-physics study of porous media heated intermittently by RF energy in a coaxial cell : Contribution à l'étude multi-physique du chauffage de milieux poreux par énergie radiofréquence intermittente dans une cellule coaxiale. [Doctoral Dissertation]. INP Toulouse; 2015. Available from: http://www.theses.fr/2015INPT0137

6. Ben Ayoub, Mohamed Wajdi. Dispositifs de mesure de constantes diélectriques dans les matériaux humides : vers une meilleure traçabilité de la mesure de l'humidité des solides : Measurement devices of dielectric constants in wet materials : towards a better traceability of the measurement of the moisture in solids.

Degree: Docteur es, Physique et sciences de la matière. Instrumentation, 2018, Aix Marseille Université

URL: http://www.theses.fr/2018AIXM0228

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Au niveau industriel, les capteurs électriques de mesure de la teneur en eau dans les solides sont généralement mono fréquentiel. La fréquence de fonctionnement est… (more)

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Au niveau industriel, les capteurs électriques de mesure de la teneur en eau dans les solides sont généralement mono fréquentiel. La fréquence de fonctionnement est choisie arbitrairement. Par contre, la sensibilité de la teneur en eau dépend du type de matériau et des liaisons d’eau existantes. D’une part, la fréquence de relaxation diélectrique de l’eau à l’état liquide est située dans la bande des Micro-ondes. D’autre part, la fréquence de relaxation diélectrique de l’eau liée dépend du matériau mais elle est dans la bande des Radiofréquences. En se basant sur cette hypothèse, le but de cette thèse consiste à analyser la sensibilité fréquentielle vis-à-vis les liaisons d’eau dans les solides en utilisant comme un paramètre intermédiaire la permittivité diélectrique complexe. La première partie du travail a eu pour objectif de valider deux cellules de mesure de type capacitive et coaxiale développées au CETIAT pour mesurer les caractéristiques diélectriques. Les deux cellules de mesure ont été validées pour mesurer la permittivité diélectrique complexe des liquides, solides et des produits humides dans la bande [1 MHz – 2 GHz] et une comparaison avec l’outil EpsiMu® développé par l’Institut Fresnel a été réalisée.En deuxième phase, nous étudions expérimentalement des matériaux humides en couplant la caractérisation électromagnétique avec la méthode thermo-coulométrique qui permet de mesurer et de distinguer sélectivement les liaisons d’eau existante dans un solide.À l’issue de cette phase, une étude paramétrique sur les spectres diélectriques complexes a été réalisée pour identifier des sensibilités par rapport aux fractions d’eau existantes.

This thesis is part of a European research project called METfnet (Metrology for Moisture in Solids).In industry, the electrical sensors for measuring the water content in the solids are generally mono-frequency and the operating frequency is chosen arbitrarily.The sensitivity to the water content depends on the type of material and the existing water bounds. On the one hand, the dielectric relaxation frequency of water in the liquid state is located in the microwave band. On the other hand, the dielectric relaxation frequency of the bound water depends on the material, but it is known that it’s situated in the radio frequency band.Based on this hypothesis, the aim of this thesis is to analyze the frequency sensitivity with respect to water bonds in solids by using as an intermediate parameter the complex dielectric permittivity.In the first phase of the work, we validate metrologically two instruments: capacitive and coaxial, both of them are developed at CETIAT for measuring the dielectric constant. The two measuring cells were validated to measure the complex dielectric permittivity of liquids, solids and wet products in the [1 MHz - 2 GHz] band and a comparison with the EpsiMu® tool developed by the Fresnel Institute was carried out. In the second phase, we experimentally study wet materials by coupling electromagnetic characterization with the thermo-coulometric…

Advisors/Committee Members: Sabouroux, Pierre (thesis director), Georgin, Eric (thesis director).

Subjects/Keywords: Permittivité diélectrique complexe; Teneur en eau; Liaisons d’eau; Fréquence de relaxation; Cellule capacitive; Ligne de propagation coaxiale; Matériaux solides.; Complex dielectric permittivity; Water content; Water bonds; Relaxation frequency; Capacitive cell; Coaxial propagation line; Solid materials.

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

APA (6^th Edition):

Ben Ayoub, M. W. (2018). Dispositifs de mesure de constantes diélectriques dans les matériaux humides : vers une meilleure traçabilité de la mesure de l'humidité des solides : Measurement devices of dielectric constants in wet materials : towards a better traceability of the measurement of the moisture in solids. (Doctoral Dissertation). Aix Marseille Université. Retrieved from http://www.theses.fr/2018AIXM0228

Chicago Manual of Style (16^th Edition):

Ben Ayoub, Mohamed Wajdi. “Dispositifs de mesure de constantes diélectriques dans les matériaux humides : vers une meilleure traçabilité de la mesure de l'humidité des solides : Measurement devices of dielectric constants in wet materials : towards a better traceability of the measurement of the moisture in solids.” 2018. Doctoral Dissertation, Aix Marseille Université. Accessed January 23, 2021. http://www.theses.fr/2018AIXM0228.

MLA Handbook (7^th Edition):

Ben Ayoub, Mohamed Wajdi. “Dispositifs de mesure de constantes diélectriques dans les matériaux humides : vers une meilleure traçabilité de la mesure de l'humidité des solides : Measurement devices of dielectric constants in wet materials : towards a better traceability of the measurement of the moisture in solids.” 2018. Web. 23 Jan 2021.

Vancouver:

Ben Ayoub MW. Dispositifs de mesure de constantes diélectriques dans les matériaux humides : vers une meilleure traçabilité de la mesure de l'humidité des solides : Measurement devices of dielectric constants in wet materials : towards a better traceability of the measurement of the moisture in solids. [Internet] [Doctoral dissertation]. Aix Marseille Université 2018. [cited 2021 Jan 23]. Available from: http://www.theses.fr/2018AIXM0228.

Council of Science Editors:

Ben Ayoub MW. Dispositifs de mesure de constantes diélectriques dans les matériaux humides : vers une meilleure traçabilité de la mesure de l'humidité des solides : Measurement devices of dielectric constants in wet materials : towards a better traceability of the measurement of the moisture in solids. [Doctoral Dissertation]. Aix Marseille Université 2018. Available from: http://www.theses.fr/2018AIXM0228

North Carolina State University

7. Moghe, Ajit Keshav. Core-Sheath Differentially Biodegradable Nanofiber Structures for Tissue Engineering.

Degree: PhD, Biomedical Engineering, 2008, North Carolina State University

URL: http://www.lib.ncsu.edu/resolver/1840.16/5676

► In recent years, it has been shown that the nanofiber structures prepared using electrospinning can serve as near ideal substrates for engineering tissues. Various biodegradable… (more)

▼ In recent years, it has been shown that the nanofiber structures prepared using electrospinning can serve as near ideal substrates for engineering tissues. Various biodegradable polymers of natural and synthetic origins have been used to construct the nanofiber scaffolds. The use of natural polymers is important in that they contain specific cell recognition sites that are capable of binding cells. Synthetic biodegradable polymers, on the other hand, can provide the necessary mechanical properties and their degradation rate can be controlled positively. When used alone, however, neither can provide an ideal structure for long-term development of tissues. This is because the regenerated natural polymers, although greatly biocompatible, are weak and degrade rapidly and uncontrollably, while the synthetic polymers, although mechanically more stable, are not as biocompatible. The focus of the current investigation was, therefore, to combine natural and synthetic polymers and to produce materials that have novel hybrid properties at the nano level. An optimum structure proposed was a differentially biodegradable bicomponent nanofiber with the sheath of natural and the core of synthetic polymers. Co-axial electrospinning was used to prepare the proposed core-sheath nanofibers. A major objective of the current research was to develop and optimize the technology to produce uniform bicomponent nanofibers of predictable morphologies by understanding the effects of various material and process variables such as solution concentration, solvent type, solution flow rate, and applied voltage. Two natural polymers (collagen and gelatin) and one synthetic biodegradable polymer (PCL) were used to develop the proposed structures. The factors that affected the bicomponent fiber formation were: interfacial tension between sheath and core solutions, volatility of the solvent, and applied voltage. By minimizing the interfacial tension, selecting the solvents with low vapor pressure, and adjusting the voltage to a value lying within a particularly narrow range, uniform bicomponent fibers were obtained. Other factors such as polymer concentrations and flow rates were shown to directly affect the dimensions of the sheath and the core. It was hypothesized that the bicomponent structures produced would be differentially biodegradable in that the natural polymer sheath would degrade relatively faster, after initiating the cell activity, and the synthetic polymer core would degrade at a much slower rate and continue to support the cell growth over the required longer period of time. Collagen-PCL sheath-core bicomponent structure was visualized as the most suitable combination for tissue engineering applications and hence, the degradation behavior of this particular structure was investigated. The results showed that for the observed thirty day period of degradation, only collagen from the sheath degraded. The degradation rate of the polymer was highest within the first hour and decreased continuously with time. The degradation within the first… Advisors/Committee Members: Dr. Bhupender S. Gupta, Committee Chair (advisor).

Subjects/Keywords: solution conductivity; synthetic polymer; natural polymer; polymer concentration; solution flow rate; bone; nanofibers; cell differentiation; degradation; interfacial tension; collagen; vapor pressure; solvent; applied voltage; nanotechnology; bicomponent; PCL; gelatin; scaffolds; stem cells; coaxial electrospinning

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

APA (6^th Edition):

Moghe, A. K. (2008). Core-Sheath Differentially Biodegradable Nanofiber Structures for Tissue Engineering. (Doctoral Dissertation). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/5676

Chicago Manual of Style (16^th Edition):

Moghe, Ajit Keshav. “Core-Sheath Differentially Biodegradable Nanofiber Structures for Tissue Engineering.” 2008. Doctoral Dissertation, North Carolina State University. Accessed January 23, 2021. http://www.lib.ncsu.edu/resolver/1840.16/5676.

MLA Handbook (7^th Edition):

Moghe, Ajit Keshav. “Core-Sheath Differentially Biodegradable Nanofiber Structures for Tissue Engineering.” 2008. Web. 23 Jan 2021.

Vancouver:

Moghe AK. Core-Sheath Differentially Biodegradable Nanofiber Structures for Tissue Engineering. [Internet] [Doctoral dissertation]. North Carolina State University; 2008. [cited 2021 Jan 23]. Available from: http://www.lib.ncsu.edu/resolver/1840.16/5676.

Council of Science Editors:

Moghe AK. Core-Sheath Differentially Biodegradable Nanofiber Structures for Tissue Engineering. [Doctoral Dissertation]. North Carolina State University; 2008. Available from: http://www.lib.ncsu.edu/resolver/1840.16/5676

University of Queensland

8. Bhuyan, Md. Habibullah. Quantification of moisture and density of unbound pavement materials using time domain reflectometry.

Degree: School of Civil Engineering, 2018, University of Queensland

URL: http://espace.library.uq.edu.au/view/UQ:93

Subjects/Keywords: Unbound granular materials; Surface deformation and rutting; Moisture content; Electrical conductivity; Material density; Time and frequency domain reflectometry method; Large coaxial cell; Rod sensor; FRC sensor; Road instrumentation; 0404 Geophysics; 0905 Civil Engineering

Record Details Similar Records Cite « Share

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

APA (6^th Edition):

Bhuyan, M. H. (2018). Quantification of moisture and density of unbound pavement materials using time domain reflectometry. (Thesis). University of Queensland. Retrieved from http://espace.library.uq.edu.au/view/UQ:93

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

Chicago Manual of Style (16^th Edition):

Bhuyan, Md Habibullah. “Quantification of moisture and density of unbound pavement materials using time domain reflectometry.” 2018. Thesis, University of Queensland. Accessed January 23, 2021. http://espace.library.uq.edu.au/view/UQ:93.

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

MLA Handbook (7^th Edition):

Bhuyan, Md Habibullah. “Quantification of moisture and density of unbound pavement materials using time domain reflectometry.” 2018. Web. 23 Jan 2021.

Vancouver:

Bhuyan MH. Quantification of moisture and density of unbound pavement materials using time domain reflectometry. [Internet] [Thesis]. University of Queensland; 2018. [cited 2021 Jan 23]. Available from: http://espace.library.uq.edu.au/view/UQ:93.

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

Council of Science Editors:

Bhuyan MH. Quantification of moisture and density of unbound pavement materials using time domain reflectometry. [Thesis]. University of Queensland; 2018. Available from: http://espace.library.uq.edu.au/view/UQ:93

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

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Open Access Theses and Dissertations