Determination of the three-dimensional velocity vector using the laser doppler measurements of unevenly sampled components

This paper describes the method for determining the three-dimensional velocity vector of the flow using the laser Doppler measurements of unevenly sampled components. This method is based on the filtering and linear interpolation of the measured velocity components in the circuit channels. It is shown in the numerical simulation and physical experiment that the method error does not exceed 2% and the results of interpolation with respect to the closest points are several times greater.     

Fluid flow with abrupt viscosity-temperature dependence

The paper is focused on studies of channel viscous flow stability with the high dependence viscosity on temperature (thermoviscosity effect). It is shown the essential influence of this effect on the entrance length or transition from any initial profile to the stationary profile of the plane channel flow. The obtained solution has an inflection point in the velocity profile for the certain range of flow parameters. This evidence with respect to Rayleigh’s inflection theorem involves thermoviscous media deserving consideration objects for stability problems.     

Optoelectronic method of contactless reconstruction of the surface profile of complexly shaped three-dimensional objects

An optoelectronic method of contactless reconstruction of the surface profile of complexly shaped threedimensional objects with the use of structured light, phase triangulation, and a steady-state method of identification of interference patterns by means of stepwise shift is considered. Analytic estimates as well as estimates obtained experimentally (using the newly developed measurement system) of the error in measurements of surface profile with the use of the proposed method are presented.     

Use of Wear-Resistant Materials in the Kazakhstani Metallurgical Industry

Metallurgist - We provide an overview of requirements for wear-resistant materials in the Kazakhstani ore mining and smelting industry, and describe the basic variety of metallurgical parts and...     

Nanofabrication with Pulsed Lasers

An overview of pulsed laser-assisted methods for nanofabrication, which are currently developed in our Institute (LP3), is presented. The methods compass a variety of possibilities for material nanostructuring offered by laser–matter interactions and imply either the nanostructuring of the laser-illuminated surface itself, as in cases of direct laser ablation or laser plasma-assisted treatment of semiconductors to form light-absorbing and light-emitting nano-architectures, as well as periodic nanoarrays, or laser-assisted production of nanoclusters and their controlled growth in gaseous or liquid medium to form nanostructured films or colloidal nanoparticles. Nanomaterials synthesized by laser-assisted methods have a variety of unique properties, not reproducible by any other route, and are of importance for photovoltaics, optoelectronics, biological sensing, imaging and therapeutics.     

Photonic structures and their application for measuring material parameters

A computer simulation and an experimental study of the frequency dependences of the transmission coefficients of photonic crystals are carried out on the basis of microstrip lines with distortion in their periodicity in the form of change in the microstrip dimensions and the permittivity of a substrate of one of the alternate pieces of the microstrip line in the range of 0–20 GHz. Good quantitative agreement between the results of calculations and experimental data is obtained. It is shown that there is a possibility of using open microwave transmission lines, namely, microstrip photonic structures, to implement a method for measuring the parameters of material samples with the specified geometrical shape and a certain size that perform a function of nonuniformity in the photonic structure.     

Optimization of a moderator-neutron guide system for diffractometers of beam line 7A of the IBR-2M reactor

Neutron guides are widely used to transport the neutrons from the moderator to the sample. Due to the constructive features of the ring corridor of the fast pulsed reactor IBR-2, the minimal distance between the moderator and the guide entrance is around 6 m. The main goal of the paper is to optimize the neutron optical system between the moderator and the entrance of the new neutron guides. Using Monte Carlo simulations we calculate the possible best gain of the neutron flux density at the guide exit. After the described optimization process, the optimal system is obtained. The recommendations for construction of the new beam line are provided too. Similar technique and the proposed system could be easily adapted for another similar beam line at the neutron sources.     

Interference microscope-profilometer

The structure and functional capabilities of a digital optical microscope-profilometer capable of operating in two modes, those of micro- and nanomeasurements, are presented. The instrument operation principle is based on measuring the phase function of the wave front of light scattered by the measured surface. Software for the microscope-profilometer and its performance characteristics are considered.