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Artificial materials with negative magnetic and dielectric permittivity have unique electrodynamic properties that are not present in natural materials. We present the results of studying of the main magnetic LC resonance induced by a plane electromagnetic wave of GHz range in the linear structures of subwavelength dielectric ring elements with a high relative permittivity. The dielectric constant of the ring material (capacitor ceramics) is 160. Resonant scattering on the main magnetic mode and wave properties of linear structures consisting of subwavelength dielectric elements in the form of flat thin rings were studied. A single ring or ring structures were arranged in such a way that the vectors of the electric and magnetic fields of a plane incident electromagnetic wave were parallel to the plane of the ring, whereas the wave vector was perpendicular to the plane of the ring. Linear structures consisting of two or three rings were oriented along the magnetic vector of the incident wave. The magnetic field probe was placed on the line of the axis of symmetry of the ring and structures relative to the wave vector at the side of the structures most distant from the antenna. The spectra of transmitted radiation were measured during resonant excitation of magnetic fields in a system of dielectric rings in the near (distance — 2 mm) and remote (distance — 30 mm) zones from the ring. It is shown that in the near wave zone, splitting of the resonant frequency occurs due to mutual inductance and interaction of the rings. As the number of rings increases, the number of additional peaks also increases. A bandwidth of ~200 MHz with an amplitude 25 dB greater than the amplitude of the incident electromagnetic wave in the specified spectrum appears between the split levels. In the far zone, the transmitted radiation at the resonance frequency for a single ring practically does not change due to the splitting of this resonance frequency due to the interaction of the rings in the structure. The results obtained can be used in the development of new materials.

The complex plasma, comprising low-pressure DC discharge plasma and charged micro-particles, represents a trap, which can accumulate and localize ions. On the surface of the micro-particles, a loss of ions and electrons always occurs. These additional losses can lead to a decrease in the ion and electron densities in the plasma bulk. However, in most cases, the collective effect of the interaction between the discharge plasma and the dust cloud leads to an increase in the ion density — both around and inside the dust cloud — in comparison with that in pure plasma at the same discharge currents. The complex plasma represents an open dissipative synergetic system. Feedbacks between plasma processes allow one to control its properties with the use of external influences of various physical fields. Such influences thus represent a tool for controlling the dust cloud parameters and the ion density. In this Letter, we report a method of determination of the ion density inside a dust cloud using the electric field-current diagram. This method is based on the statement that only a single electric field can relate to the particular values of the ion density, the discharge and the dust cloud parameters. Our method includes the procedure of imposing the electric field-current diagram to the ion density-current diagram. For calculation of plasma parameters, the fluid model of a DC discharge with micro-particles is employed. The method, proposed herein, allows us to find the conditions, under which the ion density in plasma with micro-particles is less than that in pure plasma without micro-particles — or vice versa, increases up to five times.

An atomic force microscope (AFM) is a molecular detector that allows the recording of individual proteins and protein complexes on the surface of an atomically flat substrate, the AFM chip. Registration of target proteins is carried out after the fishing procedure — catching out of proteins from the volume of the analyzed solution to a surface of a small area (sensory zone of the chip) modified by affinity reagents against the target protein. The use of the procedure of biospecific enrichment makes it possible to effectively concentrate the molecules of the target proteins in an amount sufficient for the subsequent mass spectrometric analysis for early diagnosis of ovarian cancer in blood samples.

We consider the efficiency of an ion confinement inside a cloud of charged microparticles in a low-pressure DC discharge. To describe the ion confinement efficiency in such complex plasma, we propose the indicators calculated taking into account the processes responsible for the generation, the losses, and the accumulation of ions in a cloud of charged microparticles in a plasma using a fluid model. The efficiency of ion accumulation by a microparticle cloud shows the ratio of the average ion densities in discharge with microparticles and without them. The efficiency of ion accumulation by a microparticle shows the difference of average ion densities in a discharge with microparticles and without them, related to microparticle number density. The specific power costs of the existence of one ion in a microparticle cloud determines the linear power costs of the discharge in a cloud related to the linear number of ions in it. The power efficiency of ion accumulation by a microparticle cloud is defined as a ratio of specific power costs in a discharge without microparticles, to specific power costs of ion existence in a cloud. A strong dependence of indicators on the microparticle number density has been revealed. Inefficient conditions of ion confinement inside a cloud are found. Experimental data on dynamic instabilities of a discharge with microparticles was analyzed. It is found that efficiency of ion confinement is connected with dynamic processes in complex plasma. The limiting microparticle number density is shown to serve as the criterion of the occurrence of plasma instability. Exceeding the limiting microparticle number density results, generally, in the development of dynamic instability of complex plasma, and, in inefficient states, in quenching of the discharge.

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A method for measuring the energy absorbed under a nonlinear load that employs a reverse current shunt is described. The design features of the reverse current shunt and the peculiarities of its use to study high-voltage (10–100 kV) pulses with a nanosecond duration are considered. The experimental results of applying this method to the investigation of the energy absorption during high-voltage pulse gas discharge are presented.

Experimental and numerical study of positive column of glow discharge in neon with dust particles is presented. The influence of dust structures on integral parameters was measured and simulated. Spatial distributions of electrons and electric field configuration in presence of dust cloud are represented. The reverse radial electric field direction is shown to appear within the dust cloud at high dust particle concentration. The current-voltage characteristics of discharge in neon with and without dust particles are represented. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The effect of microparticles on the current-voltage characteristics (CVC) and on the distribution of plasma components in a positive column of a glow discharge in air is studied both experimentally and numerically. The analysis is carried out on the basis of a diffusion description of the plasma of a discharge and the description of flows of ions and electrons onto the surfaces of dust particles in the orbit motion limited approximation. The CVC change is found to be connected with an increase in the volumetric losses of the charge on particles and the drift of a substantial part of the free electrons onto the particles. The radial distributions of the plasma components, the radial electric field, and the charges of the particles are calculated. The effect of a dust cloud on the configuration of an electric field and the CVC of a positive column of a glow discharge is analyzed.

Plasma with dust structures containing internal cavities (dust-void) was numerically investigated. The radial profiles of plasma components and the radial and longitudinal components of the electric field were calculated on the base of diffusion/drift model developed for the positive column of glow discharge in neon with dust particles [1]. The formation, drift, diffusion and losses of electrons, ions and metastable neon atoms were considered in plasma bulk, on the discharge tube walls and on the dust particle surface [2]. The electron temperature, transport coefficients and rate coefficients for electron impact reactions were calculated using the electron Boltzmann equation solver BOLSIG+ combined with the SIGLO Database. The dust particle charging was described in the approximation of collision enhanced collection. The distribution of dust particles in the discharge was set by a step function with a cavity inside, corresponding to the void radius and the concentration of dust particles was close to that observed in experiments [3]. Simulations were carried out for the discharge tube of radius 16.5 mm i.d. and dust particle diameter 2.55 micron. Calculations were carried out with close to the experimentally obtained values of the discharge parameters. The calculation of the radial profiles of plasma components and the radial and longitudinal components of the electric field were carrying out. It was obtained that the longitudinal electric field strength in discharge with dust structures with voids is higher than in pure neon and increases with the reduction of the void size. It was shown that the ratio of metastable atom concentration to electron concentration is higher in the presence of dust structure and increases with decreasing void radius, illustrating the difference between the rates of electron and metastable atom losses on dust particles.

The analytical analysis of the possibilities of ultrasound application, together with ultraviolet radiation or oxidizers, has been carried out. The mechanisms of the efficiency increase have been examined at decontamination of sewage with big suspended particles. The application of additional sonication of potable water is of no use. The possibilities of cleaning of quartz sleeves have been discussed.

Experimental investigations of high voltage nanosecond pulses influence on charged dust particles in low pressure rf–plasma were carried out. Application of repetitive pulses leads to the vertical oscillations of the mi-croparticles. Evolution of the total kinetic energy for the cluster consisting of 14 particles is investigated. Flat clusters exhibit parametric instabilities of horizontal modes. In the initial phase the kinetic energy oscillates around a certain value and its amplitude grows very slowly. At a certain moment during the instability it goes into the exponential growth phase and then saturates under the effect of repetitive pulses. It is possible if the eigenfrequency is the function of height and the dust particle oscillates vertically in the non uniform electric field (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The paper presents the results of the experimental measurement and the simulation of electric characteristics of dc glow discharge with the hollow cathode in neon, carried out during cooling of the discharge to the temperature of liquid nitrogen. The experiments were performed at pressure P = 18–187 Pa and discharge currents I = 0.01–3.5 mA. The behavior of the border of transition to the normal glow discharge during cooling was studied. Cooling in a subnormal discharge mode at constant current led to a change in the discharge regime. Upon cooling, the boundary of the transition to the normal glow discharge shifted to lower current, the electric field in the positive column of discharge and at the boundary of the normal glow discharge increased, but the reduced electric field decreased throughout the entire range of pressure and the discharge current.

The transition between thermal and streamer discharges has been observed experimentally in water solution with conductivity 100 μS/cm applying positive voltage pulses to pin-to-rod electrodes. The transition happens at five-fold pulse amplitude. Considering streamer propagation as an ionization wave helped to establish relation between the parameters governing transition from one to another discharge mechanism.

A bactericidal treatment analytical analysis of the potentialities of pulsed UV lamps has been carried out. A comparison of traditional low- and high-pressure mercury lamps has been performed. Devices with pulsed xenon lamps are characterized by higher power consumption, lower resources, and higher exploitation expenditures than low-pressure mercury lamps. Xenon lamps may be used in equipment or under conditions in which the mercury presence is barred.