The permittivity of heterogeneous mixtures

Lal, K.; Parshad, R.

doi:10.1088/0022-3727/6/11/311

Cited by 21 publications

(7 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This equation has been derived by Lal and Parshad [56] using somewhat different argumentation. Equations (11), (15) and (18) can be derived from Equations (6) and (7) using Equation (8) and various approximations for the effective medium [43], but in the case of Equation (18b) this derivation is only formal, as fl and f2 are interrelated, Vl [1 + v2/'2 = 1.…”

Section: Akk --Em+ (Ei-era)and"mentioning

confidence: 99%

See 1 more Smart Citation

Comparison of electrical mixture rules for composites

Bánhegyi

1986

Colloid & Polymer Sci

197

139

View full text Add to dashboard Cite

Firstly the basic theoretical methods of calculating the dielectric properties of heterogeneous mixtures are discussed. These are the mean field and effective medium theories and integral methods. Formulae are presented for systems containing parallel oriented ellipsoids and for randomly oriented ellipsoidal systems. Theoretical formulae are divided into two sub-groups: symmetric equations for statistical mixtures and asymmetric equations for matrix-inclusion type composites. In the former case only the relative amount of the components is important, in the second case phase inversion results in a change of the dielectric properties.Formulae are compared numerically using spherical and spheroidal systems with sharply different components (permittivity ratio is I : 100). In the case of asymmetric formulae the effect of phase inversion is studied as well. Percolation behaviour predicted by the equations is demonstrated and discussed. Functional shapes are compared in relation to the theoretical differences.Finally, experimental data are compared with the theoretical results, advantages and drawbacks of the various formulae are discussed. For spherical systems the simplest mean field formula yields somewhat worse values than effective medium or integral equations. The Looyenga equation does not work very well if the permittivity difference is high. For nonspherical systems the fit is better in general, even the simplest formula works satisfactorily. The shape independence predicted by the Looyenga theory for randomly oriented ellipsoids is in conflict with experimental data.

show abstract

Section: Akk --Em+ (Ei-era)and"mentioning

confidence: 99%

“…Lal and Parshad [56] have extended Looyenga's model for ellipsoids using Bilboul's earlier work [59] and derived their formula (Eq. (18b)) and the asymmetric integral formula (Eq.…”

Section: (Et -G) (Vt A'~ -A'~ -Vt) -Gmentioning

confidence: 99%

Comparison of electrical mixture rules for composites

Bánhegyi

1986

Colloid & Polymer Sci

197

139

View full text Add to dashboard Cite

show abstract

“…An effective dielectric permittivity equation is used to obtain the first estimate for how much oil should be incorporated to approach the desired THz material properties. Due to oil and water emulsions forming small, spherical micelles when mixed, this estimate is made for spherical packing using Bottcher’s equation [52]:

ν_{2} = \frac{(\tilde{ε} - {\overset{ε}{true}}_{1}) (2 \overset{ε}{true} + {\tilde{ε}}_{2})}{3 \tilde{ε} ({\overset{ε}{true}}_{2} - {\overset{ε}{true}}_{1})} .

…”

Section: Methodology and Materialsmentioning

confidence: 99%

A phantom study of terahertz spectroscopy and imaging of micro- and nano-diamonds and nano-onions as contrast agents for breast cancer

Bowman

Walter

Shenderova

et al. 2017

Biomed. Phys. Eng. Express

View full text Add to dashboard Cite

THz imaging is effective in distinguishing between cancerous, healthy, and fatty tissues in breast tumors, but a challenge remains in the contrast between cancerous and fibroglandular (healthy) tissues. This work investigates carbon-based nanoparticles as potential contrast agents for terahertz imaging of breast cancer. Microdiamonds, nanodiamonds, and nanometer-scale onion-like carbon are characterized with terahertz transmission spectroscopy in low-absorption backgrounds of polydimethylsiloxane or polyethylene. The refractive index and absorption coefficients are calculated based on the measured electric fields. Nanodiamonds show little effect on the terahertz signal, microdiamonds express resonance-like, size-dependent absorption peaks, and onion-like carbon provides a uniform increase in the optical properties even at low concentration. Due to its strong interaction with terahertz frequencies and ability to be activated for selective binding to cancer cells, onion-like carbon is implemented into engineered three-dimensional breast tumor models composed of phantom tissue mimicking infiltrating ductal carcinoma surrounded by a phantom mimicking healthy fibroglandular tissue. This model is imaged using the terahertz reflection mode to examine the effectiveness of contrast agents for differentiation between the two tissue types. In both spectroscopy and imaging, a 10% concentration of onion-like carbon shows the strongest impact on the terahertz signal and holds promise as a terahertz contrast agent.

show abstract

“…The penetration depth of CSB samples for five frequencies (13.56, 27.12, 40.68, 915, and 2450 MHz), four moisture contents(48.5, 46.8, 43.6, and 40.1%), and six different temperatures (25,40,55,70,85, and 100ºC) were calculated from average values of dielectric constants and loss factors. As shown in Fig.…”

Section: Temperature-dependent Dielectric Propertiesmentioning

confidence: 99%

“…The dielectric properties of porous material (air-particle mixture) characteristic can be estimated by mixture equations. [25][26][27] As long as using the experimental method to obtain dielectric data for homogenous and truly dense CSB materials, it was possible to use those mixture equations in calculating dielectric properties of original porous CSB. There is negligible data in the literature for CSB dielectric properties over a broad frequency range and the lack of information about the relationship between dielectric properties and influencing factors.…”

Section: Introductionmentioning

confidence: 99%

Temperature and Moisture Dependent Dielectric Properties of Chinese Steamed Bread Using Mixture Equations Related to Microwave Heating

Song

Wang

et al. 2016

International Journal of Food Properties

View full text Add to dashboard Cite

In-package pasteurization treatments based on radio frequency or microwave energy can greatly reduce the danger of microbial spoilage for Chinese steamed bread. The mixture equations methods were used to obtain dielectric properties at the frequency from 1 to 2450 MHz for the temperature range of 25-100ºC and the moisture content range of 40.1-48.5%. The effects of frequency, moisture content, and temperature on Chinese steamed bread dielectric properties were analyzed. The Bottcher Equation was adapted for calculating dielectric constant, the Landau and Lifshitz, Looyenga Equation for dielectric loss factor. Both dielectric constants and dielectric loss factors increased with increasing moisture content and temperature. Radio frequency energies had several times deeper in Chinese steamed bread than microwave energies.

show abstract

The permittivity of heterogeneous mixtures

Cited by 21 publications

References 9 publications

Comparison of electrical mixture rules for composites

Comparison of electrical mixture rules for composites

A phantom study of terahertz spectroscopy and imaging of micro- and nano-diamonds and nano-onions as contrast agents for breast cancer

Temperature and Moisture Dependent Dielectric Properties of Chinese Steamed Bread Using Mixture Equations Related to Microwave Heating

Contact Info

Product

Resources

About