The operation principle of an optical aerosol sonde is based on detection of radiation scattered in a free atmosphere from a sequence of light probing pulses emitted by LEDs at two wavelengths, 470 ...and 940 nm. Like in a lidar, echo signals are synchronously accumulated simultaneously with probing pulses. Unlike in a lidar, the recorded signal is formed by the lens system of photodetectors due to radiation scattering in a light-scattering volume of ~0.1 m
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located at short distances of ~0.2–5 m from the source. The scattered radiation entering the photodetector is not strictly backward (by 180°) as in a lidar, since the characteristic scattering angles are ~170°–180°. For a more rigorous modeling of the sonde measurement processes, with allowance for possible scattering angles, a measurement model was developed and applied based on the Monte Carlo method. To increase the signal-to-noise ratio (SNR), the optical axes of the photodetector and emitters are located at an angle of 5°, which, when using synchronous signal detection, allows one to obtain an SNR value of at least 50 at an altitude of 30 km. The probe can be easily integrated with all types of standard aerological radiosondes and, having its own navigation module and telemetry system, can also be used in autonomous flights. The all-weather aerosol backscattersonde can be used at night time for studying and monitoring polar stratospheric clouds, tropospheric and stratospheric aerosol, cirrus clouds, pyroconvection, volcanic aerosol, as well as for verifying remote methods and means of ground- and satellite-based aerosol observations. The use of the two-wave measurement technique makes it possible to reliably diagnose changes in the aerosol composition with height by the color index. In some cases, the type of aerosol is also identified. The data of probe measurements in March 2021 over Salekhard, when the temperatures of air masses inside the polar stratospheric cyclone were slightly higher than the threshold values for the formation of type I polar stratospheric clouds, are presented. Calculations of the color index indicate the dominance of sulfuric-acid aerosol at heights of 10–15 km, as well as the fact that the aerosol composition definitely changes as the height decreases, apparently due to the addition of soot particles.
We presented the results of experimental study of the synthesis of zirconium ceramic coatings partially stabilized with yttrium oxide using the electron-beam method in the forevacuum pressure range ...(1–100 Pa). The experiments were carried out with a forevacuum plasma-cathode electron source operating in the elevated (forevacuum) pressure range. In a high vacuum, at the initial stage of electron-beam heating and evaporation, the dielectric target can be charged to almost the full accelerating potential. This, in turn, negatively affects the efficiency of energy transfer from the electron beam to the irradiated target. The currently developed forevacuum plasma-cathode electron sources operate at a pressure of several to hundreds of Pascals, which is an order of magnitude higher than the operating pressure of hot-cathode or common plasma electron sources. The beam plasma generated in this range of pressure eliminates the charging effect of the dielectric target. Thereby practically all power of the electron beam is transferred to heating, facilitating evaporation of any refractory dielectric materials. The synthesized coatings with a thickness of over 100 µm were studied, and their mechanical and thermal conductive properties were measured.
The topicality of the problem stated in the title of the this article is attributable to the lack of up-to-date information on the treatment of thermal skin wounds with the use of short wavelength ...ultraviolet radiation (UVR). The objective of the present study was to evaluate the effectiveness of the courses of short wavelength ultraviolet radiation under experimental conditions using a model of standardized thermal skin wounds in rabbits starting from the proliferative phase of the healing.
The experiments were carried out on 24 grey rabbits. The thermal wounds were inflicted using a special device at a temperature of 180 degrees Celsius with a 3 sec exposition. The BOP-4 apparatus operated in the 180-280 nm wavelength range was used to treat the wounds. The total length of the treatment course was 10 days with wound irradiation during 8 to 12 minutes every other day (a total of 5 irradiation sessions throughout the study period). The study methods included morphological ones (microscopy of hematoxylin-eosin and Van Gieson-stained samples, planimetry), hematological (complete blood count), biochemical (general clinical), and microbiological (wound infestation).
The study has demonstrated the acceleration of the wound healing process as appeared from the contraction and epithelialization of the lesions, the reduction of microbial infestation, the improvement of the general condition of the animals, and positive dynamics of the hematological and biochemical parameters.
The results of the present study give evidence that shortwave ultraviolet irradiation is a highly efficient method for the treatment of the thermal skin wounds and the data obtained themselves provide an additional confirmation of the evidence-based effectiveness of light therapy.
The temperature behavior of saturation magnetization and the temperature behavior of the integral signal intensity in electron magnetic resonance spectra is experimentally studied comprehensively ...using a low-dimensional Al2O3/Ge/Al2O3/Co (aluminum oxide–cobalt–aluminum oxide–germanium) tunnel junction with different deposition velocities of a ferromagnetic metal (Co) thin layer and non-magnetic layers (Al2O3/Ge/Al2O3). The cobalt ferromagnetic layer was deposited on aluminum oxide in two ways: in one cycle of creating the structure and with atmospheric injection before deposition of the cobalt layer. The thermomagnetic curves revealed the appearance of minima observed at low temperatures on both sides of the cobalt layer. Possible sources of precession perturbations at low temperatures can be explained by: the influence of the Al2O3 layer structure on the Al2O3/Co interface; residual gases in the working chamber atmosphere and finely dispersed cobalt pellets distributed over the cobalt film thickness. The work offers information of great significance in terms of practical application, for both fundamental physics and potential applications of ultrathin films.
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