# Dielectric studies of some binary liquid mixtures using microwave cavity techniques

TL;DR: In this article, the excess parameter studies in the microwave frequency region (X-band) on complex dielectric permittivity for the binary mixtures are reported, the methods employed are fixed cavity perturbation technique and adjustable plunger cavity technique.

Abstract: The excess parameter studies in the microwave frequency region (X-band) on complex dielectric permittivity for the binary mixtures are reported. The methods employed are fixed cavity perturbation technique and adjustable plunger cavity technique. Also Gopalakrishna method is used to calculate the relaxation time of the polar solute in a non-polar solvent. The samples under study are acetonitrile, chlorobenzene, dimethyl formamide, carbon tetrachloride and benzene.

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163 citations

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TL;DR: In this article, a nonassociating mixture of a dipolar solvent, acetonitrile, and a quadrupolar solvent benzene is presented for polar solvation dynamics.

Abstract: While dynamics of polar solvation have been tabulated for a wide range of pure polar solvents, substantially less is known about the dynamic response of solvent mixtures. Here, results for polar solvation dynamics are presented for the nonassociating mixture of a dipolar solvent, acetonitrile, and a quadrupolar solvent, benzene. The solvation response observed is sensitive to the mixing of the pure solvents, affecting both the inertial and diffusive components of the solvation response function. Addition of acetonitrile to benzene increases the amplitude of the inertial response. At high benzene mole fractions, the diffusive relaxation reveals a slow component attributed to translational diffusion of the acetonitrile.

67 citations

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TL;DR: In this article, the authors measured the shift in the resonant frequency caused by the insertion of the sample inside the cavity, which can be related to the real part of the complex permittivity, ϵ′, and the change in the inverse of the quality factor of the cavity.

Abstract: The design of a cavity resonator implies to solve the Maxwell equations inside that cavity, respecting the boundary conditions. As a consequence, the resonance frequencies appear as conditions in the solutions of the differential equation involved. The measurement of the complex permittivity, ϵ* = ϵ′-iϵ″, can be made using the small perturbation theory. In this method, the resonance frequency and the quality factor of the cavity, with and without a sample, can be used to calculate the complex dielectric permittivity of the material. We measure the shift in the resonant frequency of the cavity, Δf, caused by the insertion of the sample inside the cavity, which can be related to the real part of the complex permittivity, ϵ′, and the change in the inverse of the quality factor of the cavity, Δ(1/Q), which can be related with the imaginary part, ϵ″. This is valid for very small perturbations of the electric field inside the cavity by the insertion of a sample. For materials with high losses, the perturbation can be very high, making impracticable the use of this technique. The solution is to use high volume cavities. In this work we report the design and the performance tests of a cavity to be used with high loss materials. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1687–1690, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22506

46 citations

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TL;DR: A particle swarm optimization based technique is applied on linear antenna arrays used by broadcasting base stations and seems to be very promising for improving radiation patterns of base station antenna arrays in many practical applications.

Abstract: A particle swarm optimization based technique is applied on linear antenna arrays used by broadcasting base stations. Both the geometry and the excitation of the antenna array are optimized by a suitable algorithm under the constraints of the maximum possible gain at the desired direction and the desired value of side lobe level. The matching condition of the elements of the antenna array is also required by the algorithm. The technique has been applied to antenna arrays composed of collinear wire dipoles and seems to be very promising for improving radiation patterns of base station antenna arrays in many practical applications. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1690–1698, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22505

24 citations

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TL;DR: In this paper, dielectric properties of Propanol-DMF, and Glycerol- DMF mixtures at full concentrations have been obtained by the Dielectric relaxation spectroscopy method at frequency from 20MHz to 20GHz at room temperature.

19 citations

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01 Jan 1959

TL;DR: In this paper, an iterational method is presented to solve the integrodifferential equation of the general theory of the molecular assembly, using Green's function, and the first iterational result is the Born-Green and Kirkwood's equation.

Abstract: An iterational method is presented here to solve the integrodifferential equation of the general theory of the molecular assembly, using Green’s function. The first iterational result is the Born-Green and Kirkwood’s equation. So the error introduced by the superposition approximation can be minimised with this method.

1,764 citations

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163 citations

### "Dielectric studies of some binary l..." refers background in this paper

...the conventional thermodynamic studies [1, 8] that AN-BZ and AN-CTC binary mixtures show positive excess heats, free energy and small negative excess volume....

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