Radiometric force in dusty plasmas

A radiofrequency glow discharge plasma, which is polluted with a certain number of dusty grains, is studied. In addition to various dusty plasma phenomena, several specific colloidal effects should be considered. We focus on radiometric forces, which are caused by inhomogeneous temperature distribution. Aside from thermophoresis, the role of temperature distribution in dusty plasmas is an open question. It is shown that inhomogeneous heating of the grain by ion flows results in a new photophoresis like force, which is specific for dusty discharges. This radiometric force can be observable under conditions of recent microgravity experiments.Comment: 4 pages, amsmat

Enzymatic Synthesis and Antimicrobial Activity of Oligomer Analogues of Medicinal Biopolymers from Comfrey and Other Species of the Boraginaceae Family

This study reports the first enzymatic synthesis leading to several oligomer analogues of poly[3-(3,4-dihydroxyphenyl)glyceric acid]. This biopolymer, extracted from plants of the Boragi-naceae family has shown a wide spectrum of pharmacological properties, including antimicrobial activity. Enzymatic ring opening polymerization of 2-methoxycarbonyl-3-(3,4-dibenzyloxyphenyl)oxirane (MDBPO) using lipase from Candida rugosa leads to formation of poly[2-methoxycarbonyl-3-(3,4-dibenzyloxyphenyl)oxirane] (PMDBPO), with a degree of polymerization up to 5. Catalytic debenzylation of PMDBPO using H2 on Pd/C yields poly[2-methoxycarbonyl-3-(3,4-dihydroxyphenyl)oxirane] (PMDHPO) without loss in molecular mass. Antibacterial assessment of natural polyethers from different species of Boraginaceae family Symhytum asperum, S. caucasicum, S. grandiflorum, Anchusa italica, Cynoglossum officinale, and synthetic polymers, poly[2-methoxycarbonyl-3-(3,4-dimethoxyphenyl)oxirane (PMDMPO) and PMDHPO, reveals that only the synthetic analogue produced in this study (PMDHPO) exhibits a promising antimicrobial activity against pathogenic strains S.aureus ATCC 25923 and E.coli ATCC 25922 the minimum inhibitory concentration (MIC) being 100 µg/mL

Influence of Aerosol Pollution of Atmosphere in Tbilisi on Air Electric Conductivity in Dusheti

The results of investigations of the influence of aerosol pollution of atmosphere in Tbilisi (the capital of the Georgia, city with the greatest level of air pollution) on the total air electric conductivity in Dusheti (the small city, located in 40-45 km to the north of Tbilisi) are represented

Variability of the Average Annual Air Temperature in Tbilisi Against the Background of Global Warming in 1880-2021

Some results of a study of the variability of the average annual air temperature in Tbilisi against the background of global warming in 1880-2021 are presented. For the analysis, data of the National Environment Agency of Georgia (http://www.pogodaiklimat.ru/) and the NASA Goddard Institute for Space Studies (https://data.giss.nasa.gov/gistemp/) are used. A comparison of data on the variability of the anomalies of the average annual air temperature in Tbilisi in relation to the average temperature in 1951-1980 (T:TB) with similar anomalies of the global air temperature over land and ocean (T:GL), air temperature in the northern hemisphere (T:NH), and zonal air temperature in the northern hemisphere in different latitude ranges (T:24°N-44°N, T:24°N-64°N, T:44°N-64°N and T:64°N-90°N) are conducted. In particular, the following results are obtained. Mean value of T:TB in 1880-2021 is 0.05°C and best match to mean value of T:GL (0.06°C). Max value of T:TB is 2.26 °C and best match to max value of T:44°N-64°N (1.82 °C). Min value of T:TB is -1.70 °C and best match to min value of T:64°N-90°N (-1.76 °C). Coefficient of linear correlation of T:TB with others investigation parameters change from 0.51 (with T:64°N-90°N) to 0.67 (with T:24°N-44°N). Difference between mean values T:TB in 1992÷2021 and 1880÷1909 is 1.2 °C and exactly coincides with the analogous difference for T:24°N-64°N. The trends of all studied parameters are satisfactorily described by a fourth power polynomial. For Tbilisi, a linear approximation is also acceptable

Changeability of Air Temperature and Atmospheric Precipitations in Tbilisi for 175 Years

A statistical analysis of data on monthly and seasonal values of air temperature and precipitation in Tbilisi from 1844 to 2018 was carried out. Trends of air temperature and precipitation in three period of year (year, cold and warm seasons) for 175 year observations is study. Comparison of monthly and seasonal mean values of air temperature and precipitations in two thirty years of time (1844-1873 and 1989-2018) was carried out. In particular, it was found that in the indicated periods of time there is a significance increase in air temperature for all months of the year, except May and November. As for precipitation, their growth is observed in October and November, and a decrease in July and September

Variability of the Average Annual Air Temperature in Tbilisi Against the Background of Global Warming in 1880-2021

Some results of a study of the variability of the average annual air temperature in Tbilisi against the background of global warming in 1880-2021 are presented. For the analysis, data of the National Environment Agency of Georgia (http://www.pogodaiklimat.ru/) and the NASA Goddard Institute for Space Studies (https://data.giss.nasa.gov/gistemp/) are used. A comparison of data on the variability of the anomalies of the average annual air temperature in Tbilisi in relation to the average temperature in 1951-1980 (T:TB) with similar anomalies of the global air temperature over land and ocean (T:GL), air temperature in the northern hemisphere (T:NH), and zonal air temperature in the northern hemisphere in different latitude ranges (T:24°N-44°N, T:24°N-64°N, T:44°N-64°N and T:64°N-90°N) are conducted. In particular, the following results are obtained. Mean value of T:TB in 1880-2021 is 0.05°C and best match to mean value of T:GL (0.06°C). Max value of T:TB is 2.26 °C and best match to max value of T:44°N-64°N (1.82 °C). Min value of T:TB is -1.70 °C and best match to min value of T:64°N-90°N (-1.76 °C). Coefficient of linear correlation of T:TB with others investigation parameters change from 0.51 (with T:64°N-90°N) to 0.67 (with T:24°N-44°N). Difference between mean values T:TB in 1992÷2021 and 1880÷1909 is 1.2 °C and exactly coincides with the analogous difference for T:24°N-64°N. The trends of all studied parameters are satisfactorily described by a fourth power polynomial. For Tbilisi, a linear approximation is also acceptable

Connection of Lightning Activity with Air Electrical Conductivity in Dusheti

Some results of investigations of the connection of the parameters of thunderstorm activity with the air electrical conductivity are represented

Connection of sum light aeroions concentration with natural gamma radiation and air temperature in western Georgia

Results of investigation of connection of sum light aeroions concentration (N) with environmental gamma radiation (Γ) and air temperature (T) in western Georgia are presented. Simultaneous measurements of N, Γ and T were made at 166 different points by using portable aeroions, gamma and temperature survey meters. The terrain height (H) varied from 6 to 1928 m above sea level. The statistical characteristics of the values of N, Г and T have been studied. In particular, the following results were obtained. Range of changes of investigation parameters is following: N – 450÷3100 sm-3, Γ - 40÷180 nSv/h, T - 10÷34 ˚C. Mean values: N – 1898 sm-3, Γ - 80 nSv/h, T – 24.6 ˚C. Coefficient of linear correlation (R) of individual values of N with Г, T and H accordingly are: 0.08 (level of signification α=0.25), 0.30 (α<0.005) and 0.12 (α=0.10). It is absent correlation between Г and T.A multiple linear regression equation N with Г, T and H is obtained. In particular, the variability of the individual N values with the variability of other studied parameters within the variation range is as follows (166 different points of measurements): Г – 6.9 %, T – 61.0 % and H – 47.1 %. Thus, the main factor in the variability of the content of light air ions in this case is not the ionizing effect of gamma radiation from the soil, but the air temperature (variability of radon emanation from the soil) and the height of the terrain (variability of cosmic radiation).Connection of the averaged values of N on the Г has the form of a linear function: N = 2.9228•Γ + 1671.2 (R = 0.96, α<0.005)