Application Of Dielectric Measurements Research Articles

Dielectric spectroscopy measurements on kaolin suspensions for sediment concentration monitoring

Sedimentation along with consolidation processes dictate the in situ engineering and hydraulic behavior of a particulate system such as soil. With this in view, the present investigation discusses about the application of dielectric measurements in relation to sediment concentration measurements for fine grained soils. An in-house set up comprising of open ended coaxial probes and vector network analyzer has been used to measure the dielectric behavior of kaolin suspensions in tap and deionized water. These have been further analyzed to furnish suspended sediment concentration, pore water conductivity and shape factors utilizing Complex Refractive Index Model (CRIM) and Bruggeman–Hanai–Sen (BHS) model, through the implementation of an optimization scheme. Furthermore, measured and estimated suspended sediment concentrations showed good agreement with each other in terms of statistical parameters, and a ranking of models approach reliant on three statistical criteria revealed that, CRIM outperforms BHS model for estimating sediment concentrations.

Experimental Characterization of Dielectric Properties in Fluid Saturated Artificial Shales

High dielectric contrast between water and hydrocarbons provides a useful method for distinguishing between producible layers of reservoir rocks and surrounding media. Dielectric response at high frequencies is related to the moisture content of rocks. Correlations between the dielectric permittivity and specific surface area can be used for the estimation of elastic and geomechanical properties of rocks. Knowledge of dielectric loss-factor and relaxation frequency in shales is critical for the design of techniques for effective hydrocarbon extraction and production from unconventional reservoirs. Although applicability of dielectric measurements is intriguing, the data interpretation is very challenging due to many factors influencing the dielectric response. For instance, dielectric permittivity is determined by mineralogical composition of solid fraction, volumetric content and composition of saturating fluid, rock microstructure and geometrical features of its solid components and pore space, temperature, and pressure. In this experimental study, we investigate the frequency dependent dielectric properties of artificial shale rocks prepared from silt-clay mixtures via mechanical compaction. Samples are prepared with various clay contents and pore fluids of different salinity and cation compositions. Measurements of dielectric properties are conducted in two orientations to investigate the dielectric anisotropy as the samples acquire strongly oriented microstructures during the compaction process.

Review of the Dielectric Properties of Animal and Human Tumors Determined from In Vivo Measurements.

In this article, we combine a review of the wide range of tissue dielectric studies and applications (e.g., safety, imaging, therapy) being pursued by the bioelectromagnetics community with a description of one specific application of dielectric measurements (in vivo tumor classification). The tumor measurements were acquired over a frequency range of 0.01-4.0 GHz using a technique based on the impedance change recorded by a short antenna when placed near or in a lossy dielectric. Substantial differences (up to 300%) were found between the dielectric properties of tumors (mammary adenocarcinoma, melanoma, lung carcinoma, glioblastoma and ependymoblastoma) and normal host tissues. Such differences reflect the known heterogeneity of abnormal cell growth in cancer. In addition, in vivo human measurements of breast carcinoma, normal skin and breast tissue indicate that a maximum differential power absorption (30% higher in tumor) occurs between 1.0 and 2.0 GHz. This information, when combined with tumor size, geometry, and anatomical location, enable the design and development of effective systems for the detection of tumors and for electromagnetically induced differential hyperthermia treatment. Finally, we also discuss these results in the context of other impedance and dielectric approaches used to characterize normal and neoplastic cells and tissues.

Applicability of dielectric measurements to the adsorption of beta blockers onto a pharmaceutical grade ion-exchange resin.

Applicability of dielectric measurements to the adsorption of beta blockers onto a pharmaceutical grade ion-exchange resin.

Applicability of dielectric measurements in the field of pharmaceutical formulation

Applicability of dielectric measurements in the field of pharmaceutical formulation