Ion trapping model of the ac conductivity in disordered solids.

In this paper, we develop an approach based on ions trapping to describe the conductivity spectra in disordered solids. Applying the multiple trapping model and the diffusion equation for ions, we obtained a new expression for the ac conductivity, which allows us to describe the conductivity spectra in wide ranges of frequencies and temperatures. In the high-temperature region, the new expression for the ac conductivity reproduces the Jonscher behavior, and with decreasing temperatures transforms into an expression of the NCL-type. A new expression for the ac conductivity was successfully tested on the conductivity spectra of ion-conducting glasses.

Trap-controlled proton hopping: interpretation of low-temperature dielectric relaxation of ice Ih.

A microscopic model of the dielectric relaxation of ice at low temperatures is proposed. This model is based on the mechanism of proton hopping controlled by traps created by orientation defects. Using the multiple-trapping model an expression for the dielectric relaxation time is obtained, which describes the non-Arrhenius behavior of the temperature dependence of the ice relaxation time at temperatures below 155 K.

Multiple-trapping model of dielectric relaxation of the ice Ih.

A microscopic theory of dielectric relaxation of the hexagonal ice (Ih) is proposed based on the multiple-trapping model. The theory explains the distinctive peculiarities of the relaxation time temperature behavior and the peak broadening parameter in a wide temperature range from the unified positions.

Correction of the power law of ac conductivity in ion-conducting materials due to the electrode polarization effect.

Based on the supposition related to fractal nature of transport processes in ion-conducting materials, an expression for the low-frequency ac conductivity dependence was derived. This expression for the ac conductivity generalizes the power-law dependence and gives a possibility to take into account the influence of the electrode polarization effect. The ac conductivity expression obtained is in excellent agreement with experimental data for a wide frequency range.

The influence of the secondary relaxation processes on the structural relaxation in glass-forming materials.

In the frame of fractional-kinetic approach, the model of the structural α-relaxation in the presence of the secondary ß-relaxation processes is suggested. The model is based on the rigorous bond between ß-processes with α-process and leads to the generalized and justified expression for the complex dielectric permittivity (CDP). It allows to form a new sight on the problem of the fitting of multi-peak structure of the dielectric loss spectra in glass-forming materials. The consistency of the CDP expressions obtained is based on a good fit of experimental data for binary methanol-water mixtures.

[Treatment of urolithiasis in the horse-shoe-shaped kidney].

Seventeen patients with horse-shoe kidneys and nephroliths (5 females, 12 men, age from 17 to 63 years) participated in the trial. All the patients have undergone a complete clinical and laboratory examinations. Use of modern high-tech methods in urology allows one to have a new look on nephroliths treatment in patients with horseshoe kidney. It was found effective to apply extracorporeal shockwave lithotripsy if the horse-shoe kidney contains one stone of up to 1.5 cm in size and a latent-stage pyelonephritis. Internal drainage of the ureter by a stent catheter before surgery decreases the risk of complications and provides fragmentation of the stone. In horse-shoe kidney with multiple nephroliths, conventional operation such as pyelolithotomy should be supplemented with ureter stent catheterization and extracorporeal shock-wave lithotripsy.