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

Supercontinuum generation in silicon waveguides relying on wave-breaking

Four-wave-mixing processes enabled during optical wave-breaking (OWB) are exploited in this paper for supercontinuum generation. Unlike conventional approaches based on OWB, phase-matching is achieved here for these nonlinear interactions, and, consequently, new frequency production becomes more efficient. We take advantage of this kind of pulse propagation to obtain numerically a coherent octave-spanning mid-infrared supercontinuum generation in a silicon waveguide pumping at telecom wavelengths in the normal dispersion regime. This scheme shows a feasible path to overcome limits imposed by two-photon absorption on spectral broadening in silicon waveguide

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

Air Pollution in Tbilisi in the Winter Fogs

Results of an analysis of the influence of fogs on air pollutions in Tbilisi (the capital of Georgia) in December – February 2009-2011 at the windless weather are presented

Statistical Characteristics of the Daily Max of Wind Speed in Kakheti in the Days with and without Hail Processes in 2017-2019

The statistical analysis of the daily maximum speed of wind in the days without hail processes W(I) and in the days with hail processes W(II) for 13 points of Kakheti in the period from 1 April through 31 October 2017-2019 is represented. In particular, the following results are obtained: mean values of W(I) change from 1.3 m/sec to 8.3 m/sec, mean values of W(II) change from 1.6 m/sec to 8.8 m/sec (at the stations Tsnori and Sagarejo, respectively); the difference between the mean values of W(II) and W(I) change from 0.2 m/sec (Dzveli Anaga) to 1.9 m/sec (Naendrovali) and on the average in all stations this difference is 0.9 m/sec; the distributions of mean values of W(I) and W(II) in the territory of Kakheti has the uneven nature; the map of the distribution of mean values of W(II)-W(I) on the territory of Kakheti is given;between mean values of W(II) and W(I) on all station of Kakheti practically linear connection is observed; dependence of W(I) and W(II) from H has form of third power of polinomia

Analysis of the Atmosphere Aerosol and Ozone Condition Over Tbilisi Using Satellite Data and Ground Truth Measurements

Ground-based measurements of the parameters of atmosphere in Tbilisi during the same period, which are provided by the Mikheil Nodia Institute of geophysics, were used as calibration data. Satellite data monthly averaging, preprocessing, analysis and visualization was performed using Giovanni web-based application. Maps of trends and periodic components of the atmosphere aerosol optical thickness and ozone concentration over the study area were calculated

Weather Modification in Georgia: Past, Present, Prospects for Development

Analysis of scientific and practical works on the artificial impact on the weather in Georgia in the past and at the present time (combating hailstorms, regulating the thunderstorm activity of clouds, artificial precipitation, etc.). The prospects for further development of these works are discussed

ჰაერის ეფექტური ტემპერატურის და მაგნიტური ქარიშხლების ზეგავლენა ქ. თბილისის მოსახლეობის ჯანმრთელობაზე

წარმოდგენილია ჰაერის ექვივალენტურ - ეფექტური ტემპერატურის (ჰაერის ტემპერატურის, ფარდობითი ტენიანობის და ქარის სიჩქარის კომბინაცია) საშუალო თვიური მნიშვნელობების და მაგნიტური ქარიშხლების თვიური ხანგრძლივობის ქ. თბილისის მოსახლეობის ჯანმრთელობაზე ზეგავლენის გამოკვლევის შედეგები

ფოტოქიმიური სმოგის და ოზონის სივრცულ-დროითი განაწილების შესახებ საკითხის თანამედროვე მდგომარეობა

წარმოდგენილია მიწისპირა ოზონის და ფოტოქიმიური სმოგის სივრცულ-დროითი განაწილების შესახებ საკითხის თანამედროვე მდგომარეობის მიმოხილვა. ნაჩვენებია მიწისპირა ოზონის კონცენტრაციის ტრენდი ქ. თბილისშ