Papers by Alexey Olshukov
Coatings
TiO2 films of 130 nm and 463 nm in thickness were deposited by ion beam sputter deposition (IBSD)... more TiO2 films of 130 nm and 463 nm in thickness were deposited by ion beam sputter deposition (IBSD), followed by annealing at temperatures of 800 °C and 1000 °C. The effect of H2, CO, CO2, NO2, NO, CH4 and O2 on the electrically conductive properties of annealed TiO2 thin films in the operating temperature range of 200–750 °C were studied. The prospects of IBSD deposited TiO2 thin films in the development of high operating temperature and high stability O2 sensors were investigated. TiO2 films with a thickness of 130 nm and annealed at 800 °C demonstrated the highest response to O2, of 7.5 arb.un. when exposed to 40 vol. %. An increase in the annealing temperature of up to 1000 °C at the same film thickness made it possible to reduce the response and recovery by 2 times, due to changes in the microstructure of the film surface. The films demonstrated high sensitivity to H2 and nitrogen oxides at an operating temperature of 600 °C. The possibility of controlling the responses to differ...
Environmental Monitoring and Assessment
28th International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics, Dec 8, 2022
28th International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics
Applied Sciences
The paper presents the results of in situ studies of marine particles of different nature using a... more The paper presents the results of in situ studies of marine particles of different nature using a submersible digital holographic camera (DHC) during the Arctic expedition. It also describes the features, performance specifications, and possibilities of the DHC and the DHC technology. The DHC technology can be used for noninvasive automatic evaluation of spatial and temporal characteristics of plankton, including the distribution of plankton concentrations. The comparison of quantitative analysis of zooplankton net samples and classification results using the DHC revealed that the error of the DHC classification of mesoplankton at the level of the main systematic orders was about 30%. The results of determining the data on the medium, such as water turbidity, according to the radiation shielding factor (degree) by the particles of the Suspension taxon using the DHC technology are presented; the prospects for studying the size of gas bubbles and their volume content according to the ...
Sensors
The paper presents a diagnostic complex for plankton studies using the miniDHC (digital holograph... more The paper presents a diagnostic complex for plankton studies using the miniDHC (digital holographic camera). Its capabilities to study the rhythmic processes in plankton ecosystems were demonstrated using the natural testing in Lake Baikal in summer. The results of in situ measurements of plankton to detect the synchronization of collective biological rhythms with medium parameters are presented and interpreted. The most significant rhythms in terms of the correlation of their parameters with medium factors are identified. The study shows that the correlation with water temperature at the mooring site has the greatest significance and reliability. The results are verified with biodiversity data obtained by the traditional mesh method. The experience and results of the study can be used for the construction of a stationary station to monitor the ecological state of the water area through the digitalization of plankton behavior.
OCEANS 2019 - Marseille
Technological level of existing devices has been analyzed from the viewpoint of spatiotemporal pl... more Technological level of existing devices has been analyzed from the viewpoint of spatiotemporal plankton measurements. It is shown that the digital holographic plankton sensor combines in itself the advantages of the probe method and in situ observation. The spatiotemporal capabilities and characteristics of the sensor are estimated.
"n_all" – number of all particles in a frame "n_z" – number of all particles ... more "n_all" – number of all particles in a frame "n_z" – number of all particles in a frame moving towards the attracting light source "V_aver_all" – average particle speed "V_aver_z" – average particle speed towards the attracting light source Data in lines refer to the study hour, columns "1" – data in 30 sec without lighting, "2" – in 60 sec without lighting, "3" – in 90 sec without lighting, ..., "10" – data in 300 sec without lighting, "11" – data in 30 sec after the attracting light is turned on, "12" – data in 60 sec after the attracting light is turned on, ..., "20" – data in 300 sec after the attracting light is turned on.
Field measurements to test the possibilities of the miniDHC took place at the Black Sea, near the... more Field measurements to test the possibilities of the miniDHC took place at the Black Sea, near the city of Gelendzhik from the end of June to mid-October 2019. Ashamba research vessel was used to perform accompanying measurements. Average concentration, biomass and particle sizes profiles over depth (All_Concentr_Size.xlsx), measured by the miniDHC in forward motion (submersion) at stations: No. 4 (coordinates – 44°32.1922'N 37°56.0360'E; submersion – up to 70 m), No. 5 (44°32.0743'N 37°55.3762'E; up to 100 m), No. 6 (44°31.2398'N 37°54.3828'E; up to 500 m). All_Size_Histograms.xlsx shows the distribution statistics of particle size.
OCEANS 2021: San Diego – Porto, 2021
The paper presents the results of measurements of marine particles in situ during Arctic expediti... more The paper presents the results of measurements of marine particles in situ during Arctic expedition using the digital holographic camera (DHC). Characteristics of various marine particles, including classification and statistics on taxa, depth profiles of plankton concentration were measured. DHC technology may be used without additional sensors to obtain additional information on the medium, such as volume content of methane according to bubble surfacing and water turbidity assessed by the screening coefficient of the suspension taxon.
Sensors, 2021
The paper presents an underwater holographic sensor to study marine particles—a miniDHC digital h... more The paper presents an underwater holographic sensor to study marine particles—a miniDHC digital holographic camera, which may be used as part of a hydrobiological probe for accompanying (background) measurements. The results of field measurements of plankton are given and interpreted, their verification is performed. Errors of measurements and classification of plankton particles are estimated. MiniDHC allows measurement of the following set of background data, which is confirmed by field tests: plankton concentration, average size and size dispersion of individuals, particle size distribution, including on major taxa, as well as water turbidity and suspension statistics. Version of constructing measuring systems based on modern carriers of operational oceanography for the purpose of ecological diagnostics of the world ocean using autochthonous plankton are discussed. The results of field measurements of plankton using miniDHC as part of a hydrobiological probe are presented and int...
Optical Memory and Neural Networks, 2020
A method for visualization of volumetric defects in a ZnGeP 2 single-crystal by digital holograph... more A method for visualization of volumetric defects in a ZnGeP 2 single-crystal by digital holography method using strontium vapor laser radiation is proposed. The possibility of obtaining a volume distribution of defects with dimensions of ≥15-20 μm and their identification in a crystal is shown. The identification in a ZnGeP 2 single-crystal of such volumetric defects as growth bands and needle inclusions of zinc phosphides is carried out. Processing of holographic data has resulted in determination of the periodicity of the formation of growth bands, and evaluation of physical causes leading to the appearance of growth bands with a period of ~10-20 μm, ~25-90 μm, and ~200 μm.
Unconventional Optical Imaging, 2018
A technique for data acquisition from digital holograms of particle ensembles, including preproce... more A technique for data acquisition from digital holograms of particle ensembles, including preprocessing of the digital hologram, construction of a two-dimensional display of the holographic image of investigated volume, and segmentation and measurement of particle characteristics is considered. The proposed technique is realized in automatic regime and can work in real time. Results of the technique approbation using digital holograms of sand, plankton particles in water, and air bubbles in oil are presented.
2019 IEEE Underwater Technology (UT), 2019
In the present work, we suggest to use a hydrobiological Digital Holographic Camera (DHC) probe f... more In the present work, we suggest to use a hydrobiological Digital Holographic Camera (DHC) probe for plankton research in the habitat to solve the problem of getting, digitizing, and exchanging plankton data. Technical possibilities of the developed hydrobiological DHC probe are considered based on real field data of full-scale marine works in different water areas. Variants necessary for network applications are discussed.
Applied Optics, 2021
The observation and study of defects of single-crystal multicomponent optical material is necessa... more The observation and study of defects of single-crystal multicomponent optical material is necessary to determine the qualitative characteristics and optical properties of a material and to diagnose its manufacturing procedures. This paper utilizes the digital IR-holography to measure the geometrical parameters, shape, and location of defects as well as to characterize them. The paper illustrates the examples of physical, chemical, and optical inhomogeneities. Also, the paper presents the results of the study of dynamic processes in optical elements under the influence of laser radiation with high power density. The possibility of using the digital holographic technology to determine the dynamics of optical breakdown in the Z n G e P 2 single crystal is illustrated, namely, to estimate the speed and time of breakdown development, which can be used to interpret the mechanisms of breakdown development.
The paper presents the underwater digital holographic sensor that can solve the tasks of monitori... more The paper presents the underwater digital holographic sensor that can solve the tasks of monitoring the ecosystem biodiversity and bioproductivity for fisheries. The sensor is adapted for use in the accompanying measurement mode. The results of in situ testing of the sensor are presented.
Ecology and Evolution, 2021
Abstract Current trends in the application of bioindication methods are related to the use of sub... more Abstract Current trends in the application of bioindication methods are related to the use of submersible tools that perform real‐time measurements directly in the studied aquatic environment. The methods based on the registration of changes in the behavioral responses of zooplankton, in particular Crustaceans, which make up the vast majority of the biomass in water areas, seem quite promising. However, the multispecies composition of natural planktonic biocenoses poses the need to consider the potential difference in the sensitivity of organisms to pollutants. This paper describes laboratory studies of the phototropic response of plankton to attracting light. The studies were carried out on a model natural community that in equal amounts includes Daphnia magna, Daphnia pulex, and Cyclops vicinus, as well as on the monoculture groups of these species. The phototropic response was initiated by the attracting light with a wavelength of 532 nm close to the local maximum of the reflection spectrum of chlorella microalgae. Standard potassium bichromate was used as the model pollutant. The largest phototropic response value is registered in the assemblage. The concentration growth rate of crustaceans in the illuminated volume was 4.5 ± 0.3 ind (L min)−1. Of the studied species, the phototropic response was mostly expressed in Daphnia magna (3.7 ± 0.4 ind (L min)−1), while in Daphnia pulex, it was reduced to 2.4 ± 0.2 ind (L min)−1, and in Cyclops vicinus, it was very small—0.16 ± 0.02 ind (L min)−1. This is caused by peculiar trophic behavior of phyto‐ and zoophages. The addition of a pollutant, namely potassium bichromate, caused a decrease in the concentration rate of crustaceans in the attracting light zone, while a dose‐dependent change in phototropic responses was observed in a group of species and the Daphnia magna assemblage. The results of laboratory studies showed high potential of using the phototropic response of zooplankton to monitor the quality of its habitat thus ensuring the early diagnostics of water pollution. Besides, the paper shows the possibility of quantifying the phototropic response of zooplankton using submersible digital holographic cameras (DHC).
OSA Optical Sensors and Sensing Congress 2021 (AIS, FTS, HISE, SENSORS, ES), 2021
It is shown that DHC technology allows simultaneously studying plankton and evaluating medium par... more It is shown that DHC technology allows simultaneously studying plankton and evaluating medium parameters – water turbidity and methane content by recording such marine particles as suspensions and bubbles. The results of in situ study in the Arctic are shown.
Frontiers in Marine Science, 2020
This study shows that the use of a submersible digital holographic camera as part of a multifunct... more This study shows that the use of a submersible digital holographic camera as part of a multifunctional hardware and software complex allows carrying out in situ measurements of plankton, automating the process of obtaining data on plankton, as well as classifying plankton species up to an order within the specified taxonomic groups. Such automation ensures monitoring expeditionary or stationary research of species diversity and spatial and temporal organization of zooplankton in conjunction with the hydrophysical parameters of the medium. This paper presents the full-scale results of vertical profiles and daily measurements of plankton made with the use of the submersible digital holographic camera as well as the classification of plankton in laboratory and field conditions in the automatic mode. It is shown that, within the accomplished version, the classification algorithm using the morphological parameter makes it possible to solve the problem quickly (the time required to obtain the result is less than 1 s and depends on the number of plankton particles and the frame size of a restored image); however, the classification accuracy by orders varies within 50-60%.
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Papers by Alexey Olshukov