No abstract available

[en] In this paper is presented a method to find the conditions of existence for anisotropic different plasmas which present the same reflection coefficient. The analytical dependence of the complex reflection coefficient on the plasma parameters wao examinated. Then the numerical calculations were made with the use of a computer. The results of these calculations have been plotted on a special diagram thus allowing the direct determination of the plasma parameters ωsub(p)/ω, ωsub(b)/ω, ν/ω with the reflection coefficient being known from measurements and on of the above mentioned parameters, or to establish what are the distinct sets of values for the plasma parameters ωsub(p), ωsub(b), ν for which the same reflection coefficient is obtained. The method also could be applied in two both cases of plasma explored by means of TEM mode and by guided waves respectively. (authors)

No abstract available

[en] A new simple equation for the effective permittivity of particle-filled composites is presented. The equation does not involve any free parameters in addition to the volume fraction of inclusions, the semi-axes of ellipsoidal inclusions and the permittivities of materials. Alternatively, instead of semi-axes, the percolation threshold can be used as a parameter. It is derived in a similar manner as the Maxwell-Garnett mixing equation, but by including an enhanced background permittivity effect when the volume filling ratio of inclusions increase. The result is a mixing equation which has the Maxwell-Garnett mixing equation as a low volume filling ratio limit, but which approaches the Bruggeman mixing equation as the volume fraction of inclusions increases. The mixing equation is compared with classical mixing formulae, and to numerical simulations and measurements from the literature

[en] A technique that combines a theoretical description of the electrostatic interaction and artificial neural networks (ANNs) is used to solve an inverse problem in scanning probe microscopy setups. Electrostatic interaction curves calculated by the generalized image charge method are used to train and validate the ANN in order to estimate unknown magnitudes in highly undetermined setups. To illustrate this technique, we simultaneously estimate the tip-sample distance and the dielectric constant for a system composed of a tip scanning over a metallic nanowire. In a second example, we use this method to quantitatively estimate the dielectric constant for an even more undetermined system where the tip shape (characterized by three free parameters) is not known. Finally, the proposed method is validated with experimental data.

[en] The anisotropy of the components of the complex permittivity of vanadate Co₃V₂O₈ and Co₃V₂O₈ single crystals in the paramagnetic phase are studied by optical ellipsometry in the spectral region 0.5–5.0 eV. Our experimental results support the weak anisotropy of the optical response detected earlier for axes a and c. The optical properties are also investigated along axis b. The properties of both compounds are compared. The optical spectra of both compounds along axis b are shifted toward low energies as compared to axes a and c. The maximum of the main interband absorption band of Co₃V₂O₈ is shifted toward low energies by 0.25–0.3 eV as compared to Co₃V₂O₈. The electronic structure parameters of both compounds are determined. Optical function spectra are analyzed using the results of ab initio band calculations.

[en] We report on the magneto-optical study of surface magnetization reversal in glass covered Co-rich microwires. Four different mechanisms of magnetization reversal were found to exist, depending on external magnetic field configuration. An analysis of the results obtained was performed using the theoretical model which proposes the existence of four magnetization states with different chirality. This model was developed previously to describe current-induced switching in wires with variable inner core radius. The co-existence of stable and meta-stable helical magnetic states on the microwire surface is the basic reason for the variety of mechanisms observed for the magnetization reversal

[en] This paper presents development of a capacitive microsensor to be used in monitoring of wound healing process. Wounds will heal more quickly if they are kept under a bandage and presently bandages must be removed to track the healing process. This could potentially delay the healing process. A sensor can be used to detect the presence of blood in the wound by measuring the capacitance. Blood has a higher permittivity than air or any other substance that may be in the wound and will significantly increase the total measured capacitance in the device. The presence of blood in the wound under the bandage and so in the device would signify that the wound is not fully healed. The sensor was fabricated using standard MEMS (Microelectromechanical Systems) techniques in cleanroom. The sensor was tested in present of no solution, DI water and saline solution, and capacitance was measured to be 1 pF, 35 pF and 53.3 pF, respectively. (paper)

[en] Charged particles energy losses in high-temperature plasma with a magnetic field are calculated, dielectric plasma permittivity found with quantum correlation functions being used. For strong magnetic fields when the lambda << Re << asub(e) condition is realized (lambda is de Broglie electron wave length, Re - Larmour radius, asub(e) - Debye shielding radius), the value of the Coulomb logarithm being a magnetic field function in this case is calculated and energy losses anisotropy for different direction of test particle with velocity (5) in relation to the magnetic field is analyzed. The calculation is performed for slow particles with V << νsub(e) , where νsub(e) is thermal electron velocity. It is shown that the energy losses velocity of the slow test particle in case of motion across the strong magnetic field can approximately 1.2-1.5 times surpass the losses in case of motion along the magnetic field

No abstract available