scholarly journals Применение метода диэлектрической спектроскопии для исследования свойств сыворотки крови мышей со злокачественным асцитом

2022 ◽  
Vol 92 (1) ◽  
pp. 147
Author(s):  
Ж.А. Сальникова ◽  
А.П. Смирнов ◽  
А.А. Богданов ◽  
Н.А. Верлов ◽  
Р.А. Кастро
Keyword(s):  
Blood Serum ◽  
Dielectric Spectroscopy ◽  
High Frequency ◽  
Relaxation Processes ◽  
Serum Samples ◽  
Oncological Disease ◽  
Relaxation Parameters ◽  
Ehrlich’S Ascites Carcinoma ◽  
Frequency Relaxation ◽  
Electrical Module

The article presents the results of a study by the method of dielectric spectroscopy of high-frequency relaxation processes in the blood serum of intact mice and mice vaccinated with an oncological disease - Ehrlich's ascites carcinoma. Using the formalism of the electrical module, the relaxation parameters were calculated for the serum samples of the two studied systems.

Light scattering studies of high-frequency relaxation processes in organic glass formers

1996 ◽  
Vol 8 (47) ◽  
pp. 9593-9598 ◽  
Author(s):  
R M Pick ◽  
A Aouadi ◽  
C Dreyfus ◽  
R Torre ◽  
P Bartolini
Keyword(s):  
Light Scattering ◽  
High Frequency ◽  
Organic Glass ◽  
Relaxation Processes ◽  
Frequency Relaxation

Study of High Frequency Relaxation Processes in Three Substances with the -CN Groups at the Lateral Positions

2000 ◽  
Vol 55 (8) ◽  
pp. 733-740
Author(s):  
Stanisław Urban ◽  
Bo Gestbloma ◽  
Roman Dąbrowskib ◽  
Jerzy Dziaduszekb
Keyword(s):  
Relaxation Process ◽  
High Frequency ◽  
Liquid Crystalline ◽  
Activation Barrier ◽  
Relaxation Processes ◽  
Smectic A ◽  
Smectic C ◽  
Smectic Phases ◽  
Frequency Relaxation ◽  
Cyano Groups

Abstract Three liquid crystalline (LC) substances with the cyano-groups attached at the lateral positions to the molecular cores were studied with the aid of dielectric spectroscopy methods. The high frequency relaxation process connected with the molecular reorientations around the long molecular axes was studied in the isotropic, nematic and several smectic phases. The dielectric spectra are rather complex, indicating a contribution from several molecular processes to the main relaxation process. The dielectric time changes smoothly at the phase transitions between "liquid-like" phases (isotropic -nematic -smectic A -smectic C), and becomes shorter at the transition to the "solid-like" smectic G phase with a low-ering of the activation barrier. This indicates that the molecules perform broad angle librational motions rather than overall rotational motions in this phase. In case of a substance having two cyano groups at-tached to the benzene ring, a pronounced jump-wise change of the relaxation time was observed at the isotropic -smectic A transition.

Collective and Molecular Dielectric Relaxation in Confined Liquid Crystals: Effect of Different Layer Thicknesses and Boundary Conditions

2003 ◽  
Vol 790 ◽  
Author(s):  
Fouad M. Aliev ◽  
Manuel Rivera Bengoechea
Keyword(s):  
Liquid Crystal ◽  
Boundary Conditions ◽  
Layer Thickness ◽  
High Frequency ◽  
Low Frequency ◽  
Pore Wall ◽  
Relaxation Processes ◽  
Short Axis ◽  
Librational Mode ◽  
Frequency Relaxation

ABSTRACTBroadband dielectric spectroscopy was used to study the influence of boundary conditions and layer thickness of liquid crystal (LC) confined to cylindrical pores on low frequency and high frequency relaxation processes. Low frequency measurements provided information on the relaxation of surface polarization that arose at LC – pore wall interface. The dynamics of molecular reorientations were investigated in high frequency experiments. In samples with axial orientation of molecules, the dielectric mode due to reorientation of molecules around their short axis was investigated. The homeotropic alignment of molecules facilitated the investigation of the librational mode. The behavior of this mode was different from the behavior observed in investigations of relaxation due to reorientation of molecules around their short axis. Broadening of the dielectric spectra was observed in confined LC. The broadening increases with decreasing liquid crystal layer thickness.

scholarly journals The use of the formalism of the complex electrical module in the monitoring of oncological diseases

2021 ◽  
Vol 2103 (1) ◽  
pp. 012047
Author(s):  
Zh A Salnikova ◽  
R A Castro
Keyword(s):  
Blood Serum ◽  
Cancer Patients ◽  
Activation Energies ◽  
Electrical Modulus ◽  
The Real ◽  
Relaxation Parameters ◽  
Oncological Diseases ◽  
Electrical Module

Abstract The article discusses the use of the formalism of a complex electrical module to determine the relaxation parameters α, β, τ of blood serum. Approximating formulas for the real and imaginary components of the electrical modulus, obtained from the Havrilyak-Negami equation, are given. The assumption is made that for healthy organisms the parameters α, β, τ are constant (or change insignificantly), and for cancer patients they change, and the more the disease develops, the more these parameters change. It is also assumed that the activation energies Ea of macromolecules in the composition of blood serum are different for healthy and diseased organisms. Thus, the study of the dynamics of changes in the parameters α, β, τ, Ea can be used in the monitoring of oncological diseases.

Viscoelastic relaxation in a series of polyethylacrylates and poly- n -butylacrylates

1969 ◽  
Vol 309 (1499) ◽  
pp. 497-520 ◽  
Keyword(s):  
Molecular Weight ◽  
Shear Modulus ◽  
Relaxation Process ◽  
Steady Flow ◽  
High Frequency ◽  
Relaxation Processes ◽  
Flexible Polymer ◽  
Complete Relaxation ◽  
Frequency Relaxation ◽  
Flexible Polymer Chain

The viscoelastic properties of a series of four polyethylacrylates and of four poly- n -butylacrylates have been measured in alternating shear. All measurements were made above the glass transition temperature over the temperature range - 40 to 148 °C and at frequencies of 64 kHz, 15 MHz and 30 MHz. The steady-flow viscosity of each polymer follows a dependence upon temperature according to the equation log 10 ƞ = A + B /( T - T 0 ). The limiting high frequency elastic compliance, J ∞ , is found to be sensibly independent of molecular weight for each series of polymers and varies linearly with temperature. The results obtained are interpreted in terms of additive contributions to the complex shear modulus, G *, comprising: (1) a relaxation process at relatively high frequencies which follows the same form as that observed previously in supercooled non-polymeric liquids according to the model of Barlow, Erginsav & Lamb (1967 b ). (2) a limited summation of relaxation processes at lower frequencies arising from the modes of motion of the flexible polymer chain according to the extension of the Rouse (1953) theory made by Barlow, Harrison & Lamb (1964) for an undiluted polymer having a 'most probable’ distribution of molecular weight. For the polymers investigated the polymer modes (2) contribute a major part of the steady-flow viscosity while the high frequency relaxation process (1) is mainly responsible for the limiting high frequency shear modulus. Agreement is found between experimental results, covering a significant portion of the complete relaxation region, and the calculated behaviour based upon the sum of the above two separate relaxation processes.

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