Measurement of Gradient Strain Fields with Fiber-Optic Sensors.

The results of measuring gradient strain fields by embedded or mounted point fiber-optic sensors based on Bragg gratings and distributed fiber-optic sensors based on Rayleigh scattering are discussed. Along with the experiment, the results of numerical modeling of strain measurement errors associated with the assumption of uniaxial stress state in the area of the embedded Bragg grating and measurement errors by distributed fiber-optic sensors associated with gage length are presented. Experimental results are presented for 3D printed samples and samples made of polymer composite material.

Analysis of Reliability of Strain Measurements Made with the Fiber Bragg Grating Sensor Rosettes Embedded in a Polymer Composite Material.

The results of strain measuring experiments, with the help of rosettes consisting of fiber Bragg grating sensors (FBG) embedded at the manufacturing stage in a polymer composite material are considered in this paper. The samples were made by the direct pressing method from fiberglass prepregs. A cross-shaped sample was tested under loading conditions corresponding to a complex stress state.

[Mechanism of Formation of Cardiac Arrhythmia Due to Pathological Distribution of Myocardium Conductivity].

Two mechanisms responsible for the emergence of arrhythmia are known: a change of part of the cells to a self-oscillatory mode and generation of circulating waves. In this paper, we investigate the generation mechanism of the circulating waves using the unidirectional block. One of the variants of its realization is a narrow gap between two non-conducting regions.

[Numerical Simulation of Propagation of Electric Excitation in the Heart Wall Taking into Account Its Fibrous-Laminar Structure].

The propagation of excitation wave in the inhomogeneous anisotropic finite element model of cardiac muscle is investigated. In this model, the inhomogeneity stands for the rotation of anisotropy axes through the wall thickness and results from a fibrous-laminar structure of the cardiac muscle tissue. Conductivity of the cardiac muscle is described using a monodomain model and the Aliev-Panfilov equations are used as the relationships between the transmembrane current and transmembrane potential.

[137-Cs levels in biliary and urinary tract organs of inhabitants of the Vitebsky Region who died in 2000-2001].

Elevated Cs levels in the liver, gall bladder, kidney and urinary bladder were identified by gamma-spectral assay in the victims of common and oncological pathologies who died in Vitebsk Region in 2000-2001. The nuclide concentrations were relatively higher in gall and urinary bladder tissues in both groups. No differences in Cs uptake were established.