This paper reports on the nature and history of the mineral-rich frost heave mounds—lithalsas—developed on the first terrace of the Sentsa River in Okinsky District of Buryatia. An ice core of the ...lithalsa was exposed by drilling of a 20-m borehole. The most typical feature of the isotopic diagrams, which we obtained for the ice core, is their cyclical pattern illustrating isotope minima at depths of about 3–5 m, 9–12 m, and 18–21 m, separated by two distinct isotope maxima. Most likely, this demonstrates the cyclicity of the triple flooding of the growing frost heave mound and the subsequent active evaporation of lake-march waters, which are the main source of moisture for the lithalsa ice core. Based on the detailed radiocarbon dating of organic material from the upper horizons of the highest and surrounding lithalsas, we determined the time of their formation. Organic material in drained frost-susceptible soils was intensely accumulated during the period from 0.5 to 0.2 ka BP. This is the time of the beginning of the formation of permafrost, active ice-formation, and the associated frost heave and lithalsa growth. The age of at least three of four mounds studied is not older than 200 years, it coincides with the cooling at the beginning of the 19th century.
Abstract
A research and methodological approach to calculating coal seam natural gas content and coal methane spatial resource evaluation is introduced in the paper. The research is based on the ...geological survey data about inclosing massif stratigraphy and natural properties of coals. Stresses that act in a coal seam are also taken into account here. The results allow substantiating safety-on-gas-factor technological parameters of coal mining processes beforehand.
To assess efficacy and tolerability of a novel drug form of isosorbide-5-mononitrate in patients with ischemic heart disease and stable effort angina as compared with common isosorbide dinitrate ...pills.
Patients with stable class II-III effort angina (n=30) were included into a randomized crossover study in which they received isosorbide dinitrate (nitrosorbide, 10-20 mg t.i.d.) and long acting isosorbide-5-mononitrate (ephox-long, 50-100 mg o.d.) for 3 weeks each. Efficacy of treatment was assessed by clinical data and treadmill exercise tests. Questionnaires were used for registration of frequency and intensity of attacks of headache.
The use of both isosorbide dinitrate and 5-mononitrate was associated with significant improvements of exercise tolerance however effect of mononitrate lasted longer. Nitroglycerine requirement diminished during first week of use of both drugs and remained on this level by the end of 3-rd week of treatment with mononitrate but substantially rose by the end of treatment with dinitrate. Number of attacks of headache increased during first week of treatment with both drugs, became even higher by the end of use of dinitrate and decreased by the end of use of mononitrate.
Long acting form of isosorbide-5-mononitrate ephox-long taken once daily provides sufficient antianginal effect throughout a day and is better tolerated than nitrosorbide preparation of isosorbide dinitrate with moderately prolonged activity.
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