Author: William E. WebbPublisher:
ISBN:
Category : Dielectric separation
Languages : en
Pages : 16
Book Description
Measurement of Dielectric Properties of Minerals at Microwave Frequencies
Author: William E. WebbPublisher:
ISBN:
Category : Dielectric separation
Languages : en
Pages : 16
Book Description
Measurement of Dielectric Properties of Minerals at Microwave Frequencies
Author: William E. WebbMeasurement of Dielectric Properties in the Frequency Range of 300 MHz to 3 GHz as a Function of Temperature Density
Author: Johanna B. Salsman endPublisher:
ISBN:
Category :
Languages : en
Pages : 12
Book Description
As part of the research effort on investigating the effects of microwave energy on the chemical and physical properties of minerals and ores, the U.S. Bureau of Mines, Tuscaloosa Research Center has conducted an extensive research program on identifying those properties of minerals that are affected by microwave energy, namely the dielectric constant and loss tangent. The objective was to establish a reliable data base for predicting the effects of microwave heating on minerals. The dielectric constant and loss tangent of minerals, commonly referred to as the dielectric properties, were determined utilizing the theory of microwave propagation through an open-ended air filled coaxial line that was terminated at its open end with the particular mineral under investigation and measuring the reflection coefficient of the mineral with a network analyzer. From the measured values of the reflection coefficient, the dielectric properties of the mineral could be determined. The dielectric properties of powdered minerals with medium to high electrical conductivities (tan>.0l) were measured in the frequency range of 300 MHz to 3 GHz. Since the minerals were prepared as powders, techniques were used to relate the measured dielectric properties of the powdered minerals to the dielectric properties of the mineral at its theoretical or natural density. Also, these measurements were performed as a function of temperature, from 25 deg to 325 deg C. The results of the dielectric constants and loss tangents using this method were determined to be precise within + or - 5 pct. This report describes the method of measurement and discusses the results of the Bureau's investigations into dielectric properties of minerals with the inclusion of typical measured data.
A Technique for Measuring the Dielectric Properties of Minerals at Microwave Heating Frequencies Using an Open-ended Coaxial Line
Author: J. B. SalsmanPublisher:
ISBN:
Category : Minerals
Languages : en
Pages : 19
Book Description
Handbook of Dielectric and Thermal Properties of Materials at Microwave Frequencies
Author: Vyacheslav V. KomarovPublisher: Artech House
ISBN: 160807529X
Category : Technology & Engineering
Languages : en
Pages : 186
Book Description
The application of microwave energy for thermal processing of different materials and substances is a rapidly growing trend in modern science and engineering. In fact, optimal design work involving microwaves is impossible without solid knowledge of the properties of these materials. Heres a practical reference that collects essential data on the dielectric and thermal properties of microwaveable materials, saving you countless hours on projects in a wide range of areas, including microwave design and heating, applied electrodynamics, food science, and medical technology. This unique book provides hard-to-find information on complex dielectric permittivity of media at industrial, scientific, and medical frequencies (430 MHz, 915MHz, 2.45GHz, 5.8 GHz, and 24.125GHz). Written by a leading expert in the field, this authoritative book does an exceptional job at presenting critical data on various materials and explaining what their key characteristics are concerning microwaves.
Dielectric Properties of Low-loss Minerals
Author: Ronald H. ChurchPublisher:
ISBN:
Category : Mineralogy
Languages : en
Pages : 32
Book Description
Measurements of the Dielectric Properties of Wet Snow Using a Microwave Technique
Author: Bruce D. SweenyPublisher:
ISBN:
Category : Dielectric measurements
Languages : en
Pages : 44
Book Description
An accurate method of measuring liquid water in snow covers is required to determine the properties of wet snow. The dielectric properties of wet snow must be utilized to adequately measure its liquid water content. In this study the effect of liquid water on the complex dielectric constant of natural snow is determined in the microwave frequency range. Deloor's method for calculating the dielectric constant for mixtures and the results of waveguide experiments on samples of wet snow and glass beads are used to construct a calibration curve relating the measured dielectric loss factor directly to the water content of wet snow. The results are independent of porosity, past history and chemical impurities. A relation between the effective dielectric constant and the porosity and water content is proposed and tested experimentally. The general nature of this relation is described and suggestions are made for the development of a more precise relation. It is concluded that the dielectric constant is a function of porosity and water content only.
The Measurement of the Dielectric Properties of Glass at Microwave Frequencies
Author: E. S. HotstonMicrowave Non-Destructive Testing and Evaluation Principles
Author: R. ZoughiPublisher: Springer Science & Business Media
ISBN: 9401513031
Category : Technology & Engineering
Languages : en
Pages : 283
Book Description
Microwave and millimeter-wave non-destructive testing and evaluation (NDT&E) is generally understood to mean using high-frequency electromagnetic energy to inspect and characterize materials and structures. In spite of possessing some distinct advantages in certain applications to other NDT&E techniques, microwave NDT&E has only found compared limited practical application during the past 45 years. These advantages include lack of a need for contact between the sensor and the object being inspected, the ability to penetrate dielectric materials, and superior sensitivity to certain material constituents and flaws. One factor contributing to this minimal acceptance by the NDT &E community has been a generally poor understanding in this community of the theory and practice that underlie the technology. This situation exists partly because of a paucity of microwave NDT&E textbook and reference material. Some chapters, reviews, and books aimed at filling this need have been published in the past but, for the most part, this material is based on the use of older microwave technology. However, during the past ten years great strides have been made in ternlS of the cost, size, and ease of use of microwave components. In addition, recent advances in modeling and measurement techniques have expanded the range of applications for microwave NDT&E. Such applications include inspecting modern materials such as composites, detecting and characterizing surface flaws, and evaluating the compressive strength of cement structures. These advances have created an urgent need for up-to-date textbook material on this subject.
Microwave Treatment of Minerals and Ores
Author: Antonio CumbanePublisher:
ISBN: 9783838330327
Category : Dielectric separation
Languages : en
Pages : 317
Book Description