Radiofrequency and microwave dielectric properties of shelled field corn.

  • 19 Pages
  • 4.97 MB
  • English
Agricultural Research Service, U.S. Dept. of Agriculture , New Orleans, La
Corn -- S
ContributionsUnited States. Agricultural Research Service., University of Nebraska (Lincoln campus). Agricultural Experiment Station.
The Physical Object
Paginationiv, 19 p. :
ID Numbers
Open LibraryOL15255080M

Get this from a library. Radiofrequency and microwave dielectric properties of shelled field corn. [Stuart O Nelson; United States. Agricultural Research Service.; University of Nebraska (Lincoln campus).

Agricultural Experiment Station.]. Microwave dielectric properties of individual kernels or seeds are presented for wheat, corn, soybeans, and rice. Microwave dielectric properties data at several frequencies from 5 to 15 GHz are tabulated for wheat, corn, barley, oats, soybeans, and canola.

Tabular data are also included for 11 fruits and vegetables, pecan nuts, and for insects. Microwave Dielectric Properties of Shelled, Yellow-Dent Field Corn January The Journal of microwave power and electromagnetic energy: a publication of the International Microwave Power.

Fig. Temperature dependence of the dielectric constant of shelled yellow-dent field corn. Zen tnavs L., at indicated frequencies and moisture contents at 24 C [21]. BULK DENSITY, G/CM3 Fig. Dependence of the dielectric constant of shelled yellow dent field corn. Trabelsi S, Kraszewski A and Nelson S O Microwave dielectric properties of shelled yellow-dent field corn J.

Microw. Power Electromagn.

Download Radiofrequency and microwave dielectric properties of shelled field corn. PDF

Power Electromagn. Energy 32 Cited by:   Measurement techniques for determining dielectric properties of agricultural materials in the radio-frequency (RF) and microwave ranges are. Several RF and microwave measurement techniques can be used to measure the dielectric properties of grain and seed.

In this study, a free space transmission technique was used. It has the advantage of averaging the dielectric properties over the sample volume, and it has potential for implementation in different industrial applications, because it does not require contact between the.

The power dissipated per unit volume can be expressed as: () P = ω ϵ 0 ϵ ′ (tan δ) E 2 rms = 2 π f ϵ 0 ϵ ″ E 2 rms where ϵ 0 is the permittivity of free space (×10 −12 F/m), f is the microwave frequency (Hz), and E is the electrical field strength (V/m) in the material.

For completeness, the total loss in a material is made up of the dielectric loss (from polarization. Dielectric properties of barley, corn (white and yellow), sorghum, and wheat at microwave frequencies for heating purpose were analyzed.

Details Radiofrequency and microwave dielectric properties of shelled field corn. PDF

Properties were determined atand MHz with the free space transmission method in the cereals at 20, 30, 40, 50 and 60 °C. ε´ and ε“of all the cereals decreased with increasing frequency. ε´ slightly increased with temperature, while ε. Crucial parameters in microwave heating are the dielectric properties of matter; they express the energy coupling of a material with electromagnetic microwave field and, thus, the heating feasibility (Metaxas & Meredith, ; Schubert & Regier ; Tang et al., ).

On the basis of dielectric properties, microwave devices (applicators) can. Microwave dielectric properties of particulate materials methods of obtaining dielectric properties over wide frequency ranges have become even more efficient. Recent reviews have included methods for both frequency-domain and time-domain techniques (Kaatze & Giese, ; Afsar et al., ).

Nelson S O. Radiofrequency and microwave dielectric properties of shelled field corn. ARS S Agricultural Research Service, U. ; K Kraszewski A, Kulinski S. An improved microwave method of moisture content measurement and control. Certain dielectric related properties of a food material depend on its material composition and density, and the frequency at which they are measured.

From earlier studies on shelled, yellow-dent field corn [ 7 ], it was found that the dielectric constant increased with moisture content and it was more significant at frequencies 1–20 MHz than at higher frequencies.

used for grain moisture measurement, and the need for improvements in the radio-frequency dielectric moisture method are reviewed.

Background information is presented on dielectric characteristics, with emphasis on dielectric relaxation effects and grain moisture measurement.

Dielectric Materials at Microwave Frequencies The effects of microwave energy on materials are important in industry, biology, medicine and your microwave oven Kurt Fenske and Devendra Misra University of Wisconsin-Milwaukee R adio frequency and microwave signals have numerous scientific and industrial applications in modern technology.

Abstract: Dielectric Ceramics (DRs) have revolutionized the microwave wireless communication industry globally. The three key properties of ceramic dielectrics that determine their functionality at microwave and millimetrewave frequencies include relative permittivity (ε r), unloaded quality factor Qu - the inverse of the dielectric loss (tanδ) and temperature coefficient of resonant.

Dielectric methods for rapid and nondestructive sensing of moisture content in shelled peanuts from free-space measurement of attenuation and phase shift, and their corresponding dielectric properties at temperatures ranging from 1 to 38 °C and frequencies ranging from 8 to 14 GHz, are presented.

These methods provide moisture content independent of bulk density and compensated for. The complex dielectric constant of four soils, including a sand, a silt, and two clays, was measured over the frequency range from × 10 9 Hz to 26 × 10 9 Hz. The water content of the soils was varied from g H 2 O/g soil to g H 2 O/g soil, and the temperature from 24°C to 20°C.

The dielectric relaxation spectrum of water in soils was found to be displaced to lower frequencies. dielectric and ferroelectric properties. Early navigators were familiar with magnetic behavior of ferromagnetic magnetite (Fe 3 O 4) 1 The rough dielectric properties of BaTiO 3 were discovered on ceramic specimens independently by Wainer and Solomon in.

Based on microwave dielectric properties of wheat, corn, barley, oats, grain sorghum, soybeans, canola, shelled peanuts, and pod peanuts measured over ranges of frequency and moisture content, models are developed for predicting the dielectric constant and loss factor of these commodities.

Sacilik and Colak determined the dielectric properties of corn seeds as functions of moisture content, bulk density, and frequency. They reported the moisture content was the most significant factor affecting the dielectric properties of corn seeds.

Also, dielectric constant and loss factor increased with increasing moisture content. Dielectrics and dielectric properties are defined generally and dielectric measurement methods and equipment are described for various frequency ranges from audio frequencies through microwave frequencies.

These include impedance and admittance bridges, resonant frequency, transmission-line, and free-space methods in the frequency domain and time-domain and broadband techniques.

This study was conducted to investigate the effect of salt content during radio-frequency (RF) heating on rate of temperature increase, dielectric properties (DPs), and reduction of pathogens in.

Dielectric properties of materials influence the interaction of electromagnetic fields with and are therefore important in designing effective dielectric heating processes.

We investigated the dielectric properties (DPs) of pecan kernels between 10 and MHz using a Novocontrol broadband dielectric spectrometer in a temperature range of 5–65 °C and a moisture content range of Microwave frequencies occupy portions of the electromagnetic spectrum between MHz to GHz.

The full range of microwave frequencies is subdivided into various bands (Table 1).Because microwaves are also used in the communication, navigation and defence industries, their use in thermal heating is restricted to a small subset of the available frequency bands.

The dielectric properties of grains and seeds are important for many applications such as, moisture content determination by electrical means (Nelson, ) and control of stored grains from insects through radio frequency (RF), dielectric heating (Nelson and Charity, ) and sorting and cleaning of seed mixtures by dielectric methods.

electric field and lagging of the polarization vector behind the high frequency electric field by virtue of the inertia of the molecules, are the phenomenon responsible for the frequency dependence of dielectric properties [7]. The temperature dependence of the dielectric properties of materials is.

Certain dielectric related properties of a food material depend on its material composition and density, and the frequency at which they are measured.

From earlier studies on shelled, yellow-dent field corn [ 7 ], it was found that the dielectric constant increased with moisture content and it was more significant at frequencies 1–20 MHz than. where P, E, H, ε 0, and μ 0 are the absorbed power by volume, electric field intensity, magnetic field intensity, permittivity of free space, and permeability of free space, respectively.

The dielectric properties and intensities of the electric and magnetic fields are the key parameters to manipulate to obtain the high-efficiency energy propagation of electromagnetic waves. Excessive amounts of chemicals and ions flowing into water sources, which are mainly due to efflux from agricultural lands, cause serious environmental and human-health related concerns.

Description Radiofrequency and microwave dielectric properties of shelled field corn. PDF

The lack of affordable and real-time monitoring systems for these contaminants limits effective conservation and management strategies. To establish a basis for developing an effective, fast, real-time, and. Get this from a library! Dielectric properties of agricultural materials and their applications.

[Stuart O Nelson] -- Dielectric Properties of Agricultural Materials and Their Applications provides an understanding of the fundamental principles governing dielectric properties .Goals / Objectives To identify relationships between dielectric properties of agricultural products and their important quality characteristics and to develop sound scientific principles for measuring these characteristics through interaction of radio-frequency and microwave electromagnetic fields with the products.

Emphasis will be placed on development of improved technology for reliable.Effects of "Natural" Water and "Added" Water on Microwave Dielectric Properties of Shelled Corn at Microwave Frequencies.

Journal of Microwave Power and Electromagnetic Energy. Influence of Water Content on RF and Microwave Dielectric Properties of .