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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"dielectric measurements"”.
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Dielectric Measurements for Organ Cryopreservation
… rapid. One proposed warming technique employs dielectric heating using electromagnetic energy at microwave frequencies. Crucial to the design of any such rapid warming system are the electrical properties of the material to be heated. This dissertation describes two measurement systems that …
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Potassium Sodium Bismuth Titanate Ceramics: Processing and Property Relationships for Higher-Temperature Electromechanical Actuation
… was identified by X-ray powder diffraction, dielectric measurements and field-induced polarization and strain studies. The lowest transition temperature (and subsequently the highest electromechanical activity) was obtained at the morphotropic boundary composition (x = 0.2). Higher potassium …
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Microwave heating of a coating on a temperature-sensitive substrate
… for a candidate system. The study consisted of dielectric property determination, development of heat transfer models to determine the heat generation rates necessary to achieve a desired temperature distribution, calculation of the required electric field strength given the dielectric …
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Evaluation and design of polymer systems for enhanced microwave heating
… perfiuoroelastomer) was evaluated using dielectric testing and monitored processing in a multimode microwave cavity. Dielectric measurements were made using a field perturbation technique and a transmission/reflection technique. The electric loss factor of the epoxy system continuously …
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Development of phonon-polarization THz spectroscopy, and the investigation of relaxor ferroelectrics
… this technique to make the first THz frequency dielectric measurements of a relaxor ferroelectric crystal, in particular KTao0.982Nb0.018O3 (KTN 1.8). THz spectroscopy has emerged as an important probe for a wide variety of systems with the development of pulsed THz radiation sources and …
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Synthesis and Characterization of Mixed-Metal Phosphonates For Polymer Dielectric Composite Materials
… of ternary oxides for incorporation into polymer dielectric composites has been increasing recently. Traditionally, these surface modifications have been achieved via organosilanes. While an excellent approach for preparing surface-modified oxides, hetero-condensation between the organosilane …
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Thin film BCZT in a capacitive thermo-electric converter
… The idea of using a temperature dependent dielectric to turn heat into electricity has been around for several decades but has never been feasible due to low efficiency and the practical difficulty of being able to thermally cycle the dielectric material quickly enough. However, thin film …
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Measurements and analysis of the microwave dielectric properties of tissues
Knowledge of the microwave dielectric properties of human tissues is essential for the understanding and development of medical microwave techniques. In particular, microwave thermography relies on processes fundamentally determined by the high frequency electromagnetic properties of human tissues. …
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The cure of and moisture ingress into epoxy resins
… the cure of several epoxy resin systems using dielectric spectroscopy, DSC, FT-IR spectroscopy and rheology measurements. It was hoped to build up an understanding of the cure process and correlate the results produced by the different methods to establish whether dielectric spectroscopy can be …
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Low Frequency Dielectric Investigations on Hydrated Pharmaceutical Powders
Measurements of dielectric properties on hydrated systems at low frequencies, present particular difficulties with regard to the phenomenon of electrode polarisation, which can mask the dielectric properties of the sample. The reproducibility of DRS measurements on powdered systems has also been …
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Quantum Tuning and Emergent Phases in Charge and Spin Ordered Materials
… This work presents the first high-precision dielectric measurements under hydrostatic pressure carried out on a quantum critical ferroelectric, leading to a full pressure-temperature phase diagram for SrTiO$_3$. The influence of quantum critical fluctuations is seen to diminish as the system …
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BaTiO₃ based materials for piezoelectric and electro-optic applications
… technique in order to test the piezoelectric and dielectric properties. Some compositions were then chosen for thin film deposition. The films were deposited using pulsed laser deposition on MgO and SOI substrates. Growth orientation, remnant strain and optical properties were then measured. X-ray …
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Condition Analysis of Concrete Bridge Decks in Utah
… visual inspection, hammer sounding and chaining, dielectric measurements, ground-penetrating radar imaging, resistivity testing, half-cell potential testing, and chloride concentration testing. The condition assessment testing confirmed that chloride-induced corrosion of reinforcing steel is the …
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Investigation of Adhesive and Electrical Performance of Waterborne Epoxies for Interlayer Dielectric Material
… waterborne epoxy emulsion poses a concern for dielectric performance and adhesive durability. Another problem involves the crystallization of insoluble solid dicyandiamide (DICY), which is significantly different in morphology than that found in solution cast resins. A two-stage drying model …
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Magnetic Ionic Liquids: Design, Properties and Application
… transition-metal based ionic liquids. By using dielectric measurements, we were able to investigate the effects of temperature and, importantly, pressure on the coordination behaviour of a cobalt thiocyanate-based system over very wide frequency, temperature and pressure ranges, meaning the …
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Stability of polarization in organic ferroelectric metal-insulator-semiconductor structures
… as the gate insulator. Dielectric measurements have been carried out on all-organic metal-insulator-semiconductor structures with the ferroelectric polymer poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)) as the gate insu-lator. The capacitance spectra of MIS …
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Structure Evolution of Silica Aerogel under a Microwave Field
… using a single mode microwave oven at 2.45GHz. Dielectric properties were measured using the cavity perturbation method, and structural characterization was carried out using a variety of techniques, including absorption surface analysis, Helium pycnometry, Archimedes principle, Fourier …
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Dual parametric sensors for highly sensitive nucleic acid detection
… confining them to occupy a major fraction of the dielectric volume. This decreases the potential drop across the electrodes and thus dielectric measurements at low frequencies are made possible. The dielectric properties during hybridization reaction were measured using 10- mer nucleotide …