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[en] Oil shale power plants are the biggest atmospheric polluters among all stationary sources in Estonia. The main goal of this research is to evaluate long range transport and deposition of all air pollutants (dust, SO2, SO42-, CO NOx, heavy metals) from oil-shale power plants and enterprises in the region for different initial conditions (climate parameters, number of sources, emission data) and to estimate the composite loading and influence of these contaminants on the ecological systems (forests, soils, water bodies). Method of simulation modelling as the main method of system analysis was chosen for this complex ecological problem. According to the recommendations of Working Group of the Economic Commission for Europe and the Nordic Council, a sulfur deposition level of 1.000 mg S/m2 year is considered as critical load protecting sensitive ecosystems. About 150 km2 of sea and land territory of Estonia are with sulfur deposition exceeding this critical load. The most polluted area is situated near Narva where the level of sulfur deposition is more than 10,000 mg S/m2 year. According to the EMEST model calculations, the average annual ground level of SO2 (emitted from observed point sources only) in this region are large and vary from 0.003 mg/m3 to 0.037 mg/m3 (near Narva). It is below maximum permissible concentration 0.050 mg/m3. The observed value of average concentration in Narva in 1989 has been equal 0.050 mg/m3. The results obtained suggest that emissions from oil-shale power plants have considerable impact on the coniferous forests in Estonia in the region where the level of sulfur deposition exceeds 1,000 mg S/m2 year. 4 figs., 2 tabs., 10 refs
[en] Isolated clinical syndrome (ICS) - neurological event may be the first manifestation of a complex disease such as is also multiple sclerosis (SM). ICS has many forms, however SM are highly probable and characteristic: unilateral optic neuritis, brain syndrome strain / cerebellum and partial transverse myelitis. Early diagnosis and subsequent treatment of ICS patients can delay the severe consequences of the disease. The last revision of McDonald's criteria in ICS patients is significant simplifying the criteria, while maintaining their high sensitivity and specificity, thereby speeding up the SM diagnosis process. (author)
[en] The structural and electrical characteristics of In0.53Ga0.47As epitaxial films, grown in the low-temperature mode on InP substrates with (100) and (411)A crystallographic orientations at flow ratios of As4 molecules and In and Ga atoms of γ = 29 and 90, have been comprehensively studied. The use of InP(411)A substrates is shown to increase the probability of forming two-dimensional defects (twins, stacking faults, dislocations, and grain boundaries), thus reducing the mobility of free electrons, and AsGa point defects, which act as donors and increase the free-electron concentration. An increase in γ from 29 to 90 leads to transformation of single-crystal InGaAs films grown on (100) and (411)A substrates into polycrystalline ones.