Saturation effect for dependence of the electrical conductivity of planar oriented nematic liquid crystal 6CB on the concentration of Cu7PS6 nanoparticles

The influence of Cu7PS6 nanoparticles with the average size 117 nm on the dielectric properties of planar oriented nematic liquid crystal 6CB has been investigated within the frequency range 10(1) ...10(6) Hz and at the temperature 293 K. It has been shown that when changing the concentration of nanoparticles within the range 0 to 1 wt.%, the conductivity of the liquid crystal changes stronger than its dielectric permittivity. It has been shown that the electrical conductivity increases monotonously with increasing the concentration of nanoparticles. However, for this dependence a saturation effect is observed. The mechanism of this effect was proposed.info:eu-repo/semantics/publishedVersio

Two-step percolation in aggregating systems

The two-step percolation behavior in aggregating systems was studied both experimentally and by means of Monte Carlo (MC) simulations. In experimental studies, the electrical conductivity, $\sigma$, of colloidal suspension of multiwalled carbon nanotubes (CNTs) in decane was measured. The suspension was submitted to mechanical de-liquoring in a planar filtration-compression conductometric cell. During de-liquoring, the distance between the measuring electrodes continuously decreased and the CNT volume fraction $\varphi$ continuously increased (from $10^{-3}$ up to $\approx 0.3$% v/v). The two percolation thresholds at $\varphi_{1}\lesssim 10^{-3}$ and $\varphi_{2}\approx 10^{-2}$ can reflect the interpenetration of loose CNT aggregates and percolation across the compact conducting aggregates, respectively. The MC computational model accounted for the core-shell structure of conducting particles or their aggregates, the tendency of a particle for aggregation, the formation of solvation shells, and the elongated geometry of the conductometric cell. The MC studies revealed two smoothed percolation transitions in $\sigma(\varphi)$ dependencies that correspond to the percolation through the shells and cores, respectively. The data demonstrated a noticeable impact of particle aggregation on anisotropy in electrical conductivity $\sigma(\varphi)$ measured along different directions in the conductometric cell.Comment: 10 pages, 6 figure

Optical Properties of atmospheric dust from twilight observations

Three methods of approximation are described and used to separate the primary twilight brightness from the observed brightness. Photoelectric observations obtained are combined with observations from a balloon and from the observatory to derive the atmospheric scattering phase functions of 0.37 micron and 0.58 micron as a function of height. Comparison of these data with data for a Rayleigh atmosphere provide information on the optical properties of dust in the upper atmosphere

Diffraction scattering of 6Li ions from atomic nuclei

Using formalism of diffraction approximation, the elastic scattering of 6 Li ions from 28Si, 40Ca, and 90Zr nuclei has been investigated at an incident energy of 35 and 53 MeV per nucleon. We have considered 6 Li nucleus as a weaklybound one that consists of two charged clusters, there are deuteron and alpha-particle. The calculated angular distributions of cross sections satisfactorily fit corresponding experimental data

Dynamics of cytokine profile in patients with abdominal sepsis caused by pancreonecrosis

Acute pancreatitis is one of the most pressing problems of modern pancreatology, according to the authors ranks first among surgical pathologies.The aim of this study was to evaluate the dynamics of cytokine profile in patients with abdominal sepsis caused by pancreatic necrosis.Materials and methods.The study was conducted in 12 patients diagnosed with abdominal sepsis caused by pancreatic necrosis, in the period from 2017 to 2020 who were treated in medical hospitals in Chernivtsi and Ternopil. The control group consisted of 17 patients without signs of abdominal sepsis and acute surgical pathology. Both groups were representative by age, sex, comorbidities, risk factors. Determination of experimental parameters in the blood of patients was performed in the postoperative period (the results were evaluated before surgery, on the first and tenth days of the postoperative period).Research results and their discussion.In patients with abdominal sepsis, a violation of the mechanisms of cell adhesion and costimulatory-cooperative interaction of immunocompetent cells was observed in the preoperative period, as indicated by the low level of CD11a + and CD162 + expression on them. The decrease in the content of IL-6 in the blood with a slight progressive increase in the level of IL-4 corresponds to a moderate imbalance of cytokine regulation of the immune response