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"Kozlov, V. S."
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An empirical model of optical and radiative characteristics of the tropospheric aerosol over West Siberia in summer
An empirical model of the vertical profiles of aerosol optical characteristics is described. This model was developed based on data acquired from multi-year airborne sensing of optical and microphysical characteristics of the tropospheric aerosol over West Siberia. The main initial characteristics for the creation of the model were measurement data of the vertical profiles of the aerosol angular scattering coefficients in the visible wavelength range, particle size distribution functions and mass concentrations of black carbon (BC). The proposed model allows us to retrieve the aerosol optical and radiative characteristics in the visible and near-IR wavelength range, using the season, air mass type and time of day as input parameters. The columnar single scattering albedo and asymmetry factor of the aerosol scattering phase function, calculated using the average vertical profiles, are in good agreement with data from the AERONET station located in Tomsk. For solar radiative flux calculations, this empirical model has been tested for typical summer conditions. The available experimental database obtained for the regional features of West Siberia and the model developed on this basis are shown to be sufficient for performing these calculations.
Journal Article
A Device for Mobilization of the Greater Pectoral Muscle during Endoprosthetic Surgery
A device for mobilization of the greater pectoral muscle during endoprosthetic surgery was developed at the Samara Regional Clinical Oncology Center (Utility model patent No. 175229; November 28, 2017). The device makes the surgery less traumatic, reduces the volume of blood loss and the duration of surgery, and improves the quality of visualization of the surgical area. It allows the rate of injuries to the greater pectoral muscle to be reduced.
Journal Article
Prospects of using neutron beams for gamma-resonance spectroscopy
A model of an electrodynamic Mössbauer spectrometer has been developed by the NRC “Kurchatov Institute”—PNPI (Gatchina, Russian Federation). The model represents a prototype using the neutron beam of the PIK reactor, which is generated using either constant or periodic activation of a γ-source, and isotope sources for structural and physicochemical studies of steel and alloys, minerals, catalysts, nanostructures, and biological objects. The article presents the physical characteristics of the model, as well as the sample preparation methodology and measurement modes with sample cooling to liquid nitrogen temperature. The experiments performed on a crystal hydrate with initially divalent iron admixed with Fe
3+
have demonstrated the capabilities of the spectrometer for non-destructive testing of chemical reactions. The potential of the spectrometer in nanotechnology is illustrated by the results of studying magnetic graphene oxide composites and nanodiamonds grafted with europium ions.
Journal Article
Localization and Charge State of Metal Ions in Carbon Nanostructures of Europium Bis-Phthalocyanine Pyrolysed Derivatives
In the experiments of Mössbauer spectroscopy, transmission electron microscopy (TEM) and atomic force microscopy (AFM) the morphology and structurization of the carbon phase, the charge state of europium and the dynamic properties of europium bis-phthalocyanine pyrolysed derivatives, including the Debye temperature, were revealed. It was found that the pyrolysis of europium bis-pthalocyanine resulted in the amorphous carbon matrix and nanoscaled graphene clusters both forming turbostratic carbon phase. The europium ions in the charge state Eu
3+
/Eu
2+
were detected. The data indicated that localization of Eu ions took place between layers of graphenes similar to graphite intercalation compounds. It was shown that an isomeric shift, linewidths and the magnitude of the resonant absorption are essential characteristics of structural transformations at the pyrolysis of rare earth bis-phthalocyanines.
Journal Article
Porphyrin complexes of transition metals with a large dipole moment as active components of new film electret materials
This paper presents the results of a systematic study aimed at searching for organometallic molecules with a large dipole moment in order to create new film electret materials. A number of porphyrin complexes of transition metals, titanium, and vanadium and also complexes with bismuth(
iii
) iodide with an axial metal—oxygen bond were synthesized. The obtained compounds were identified by physicochemical methods (IR spectroscopy and X-ray photoelectron spectroscopy). The optimized geometry of the complexes, their vibrational spectra, dipole moments, and charge density distributions were evaluated by quantum chemical calculations. The Mulliken population analysis was performed. The maximum dipole moments were found for BiI etioporphyrin II (6.47 D) and BiI 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (3.87 D). The metal ion acts as a transmitter of electron density from nitrogen atoms to the counterion, resulting in an increase in the dipole moment of the molecule as a whole compared to the starting porphyrin ligands. The inclusion of porphyrin complexes under the action of an electric field resulted in the formation of polyvinyl acetate films. Copper layers 100 nm thick were deposited by magnetron sputtering onto both sides of these films. The dielectric properties and the temperature dependences of thermally stimulated depolarization currents of the obtained samples were studied. All samples were found to have a pronounced electret effect.
Journal Article
Histopathological and ultrastructural changes in the rats brain after air shock wave impact
The using of explosive substances and devices can lead to brain injuries, the diagnosis of which requires the determination of primary biomarkers. Therefore, the aim was to establish and study histopathological and ultrastructural changes in the rats brain after exposure to an air blast wave. The study was carried out on 18 male Wistar rats, which were randomly divided into two groups: sham (n=9) and experimental (n=9). The animals of the experimental group were anesthetized with halothane and gently fixed in a horizontal position on the abdomen with the front part of the rat's muzzle at a distance of 5 cm from the device opening and subjected to an excess pressure of 26-36 kPa. Animals of both groups were decapitated, brains were removed, fixed, histopathological and ultrastructural analyzes were conducted using standard methods. Intergroup differences were assessed by Mann-Whitney U-test. Light microscopy revealed primary lesions in the form of small focal, multifocal hemorrhages, cerebral vessel ruptures and microscopic ruptures of the brain substance. In almost all brain samples, there is a significant saturation of the venous vessels with the presence of erythrocyte stasis. Violation of the blood-brain barrier, the presence of edema of the perivascular space, and petechial hemorrhages in the neuropil were registered ultrastructurally. Based on the study results, a morphological algorithm for assessing primary histostructural intracranial brain injuries and their consequences after exposure to an air shock wave was proposed. The injuries were found to be caused by the direct traumatic effect of the air shock wave. In the acute post-traumatic period, histopathological and ultrastructural changes in the brain can manifest as changes in neurons and in the blood-brain barrier and be accompanied by perivascular multifocal small-focal hemorrhages, neuropil ruptures, edema of pericellular and perivascular spaces, which together can be considered as biomarkers of primary traumatic changes after exposure to an air shock wave.
Journal Article
Complex experiment on studying the microphysical, chemical, and optical properties of aerosol particles and estimating the contribution of atmospheric aerosol-to-earth radiation budget
The primary objective of this complex aerosol experiment was the measurement of microphysical, chemical, and optical properties of aerosol particles in the surface air layer and free atmosphere. The measurement data were used to retrieve the whole set of aerosol optical parameters, necessary for radiation calculations. Three measurement cycles were performed within the experiment during 2013: in spring, when the aerosol generation is maximal; in summer (July), when atmospheric boundary layer altitude and, hence, mixing layer altitude are maximal; and in late summer/early autumn, during the period of nucleation of secondary particles. Thus, independently obtained data on the optical, meteorological, and microphysical parameters of the atmosphere allow intercalibration and inter-complement of the data and thereby provide for qualitatively new information which explains the physical nature of the processes that form the vertical structure of the aerosol field.
Journal Article
Color recognition of dermatoscopic images of skin neoplasms
The problem of determining the colors of dermatoscopic images of skin neoplasms using computer technologies is considered. Based on the proposed model, a program for recognizing the colors of the studied areas of neoplasm has been developed. The adequacy of this model was tested experimentally. This work is designed to increase the reliability of the diagnosis of skin neoplasms.
Journal Article
The dynamics of humoral immunity factors in rats under experimental BLV infection
Analysis of the dynamics of some the most indicative markers of humoral immunity of BLV -infected rats and their offspring are presented in the article. Despite the dynamics of markers in adult rats and their offspring is somewhat different, certain tendencies are revealed. It is shown that in infected rats the immunological reaction develops according to the principle of inhibition due to an increase in the IL-1Ra content. The complement system activation occurs along the classical path against the background of an increase in C4 complement component titer. C3a and C5a complement proteolytic fragments are numerously presented in BLV -infected rats, compared to control group animals, which is a marker of an allergic reaction.
Journal Article