0000000000846815
AUTHOR
Beatriz Garcia-banos
Frequency Deviation Due to a Sample Insertion Hole in a Cylindrical Cavity by Circuital Analysis
One of the most widely used techniques for dielectric material characterization is the partially filled circular cavity. The exact analysis of this structure is well known in the bibliography. But in practice when the measured material is introduced through a circular pipe below its cut off frequency a problem arises. Traditionally the tube effect is neglected, but then some errors appear, whose magnitude depends on the material properties and the cavity and tube dimensions. In some cases, the errors introduced are noticeable and the tube effect should not be neglected. Some authors have tried to evaluate in a simple way this effect, but their equations are valid only in a restricted range …
Noninvasive monitoring of polymer curing reactions by dielectrometry
A microwave sensor system for the noninvasive monitoring of the curing process of a thermoset material placed inside a metallic mold is described. The microwave sensor is designed as an open-ended coaxial resonator with a curved surface adapted to the mold inner shape. The analysis of the microwave resonator comprises a recently developed method for deembedding the effect of coupling network in overcoupled resonators, so the range of permitted measurements encompass both low and high dielectric losses of polymeric materials. Results show that noninvasive, continuous monitoring of the microwave dielectric properties of the thermoset material can be performed in real time, allowing one to che…
Feasible glass‐melting process assisted by microwaves
[EN] The advantages of microwave (MW) energy processing have been verified in the sintering of a ceramic frit at a pre-industrial scale. The challenge of achieving high temperature using MW energy at such dimensions was overcome and a mix of natural raw materials was heated until its fluxing point. Changes in dielectric properties of the raw materials mix were also measured in situ with the increase in temperature, being in accordance to thermal processes of a conventional heating process. The properties of the resulting ceramic frit were compared with the same frit obtained by the conventional sintering method. Both frits showed similar thermal behavior regarding DTA-TGA, heating microscop…