Development of the method of laser Doppler spectroscopy of nanoparticles in liquids and implementation of the method in the LAD-079 spectrometer

In this work, a method for physicochemical and biological optical studies of the nanoparticles size distribution is developed. Its implementation in the LAD-079 spectrometer is described. The distinctive features of the LAD-079 spectrometer include the following. Multi-angle parallel measurements of static and dynamic light scattering, scattering angle from 0–180 degrees. Probing at three wavelengths with the ability to analyze the polarization activity of the sample (488 nm, 532 nm, 650 nm). Programmable precision thermostat with an error less than 0.1 °C in the range 0 ÷ +80°C with the possibility of building and software implementation of the experiment plan. Robust monobloc design of the spectrometer that does not require adjustments and a special optical table. The ability to measure the size of dispersed nanoparticles in low-transparent liquids.

Features of Designing Computer Control Systems for Precision Thermoelectric Coolers

An effective electrical circuit and an operating algorithm have been developed, and a working sample of a thermoelectric precision thermostat has been designed with the possibility of autonomous operation, continuous monitoring and recording of the temperature log using a computer or smartphone. It is shown that the developed algorithm provides effective shockless control and an accuracy of maintaining the temperature of 0.03°C, with a power consumption of 3-7 W. A design and a specialized computer control system for a multistage cryogenic thermoelectric cooler have been developed.