Characterisation of fly ashes from 4th Thermal Power Station of Ulaanbaatar city and its applicability for a zeolite synthesis

Fly ash from 4th thermal power station of Ulaanbaatar city have been characterised by x-ray fluorescence (XRF), x-ray diffractometry (XRD), particle size analyzer, specific surface area measurement (BET) and scanning electron microscope (SEM) observation. It was found that fly ash from Baganuur coal contains over 15 wt.% of calcium oxide (CaO) and could be assigned as class C fly ash, according to the International classification. Specific surface area of this fly ash was 2.75 m2/g and mean particle diameter was 59.5 μm. Zeolitic compounds were synthesised by using mixture of this fly ash and a transition aluminium oxide under hydrothermal treatment at 100, 150 and 200°C temperatures for a different duration. Various zeolitic compounds including Na-faujasite and sodium aluminosilicate were synthesised as reaction products.DOI: http://dx.doi.org/10.5564/mjc.v12i0.164 Mongolian Journal of Chemistry Vol.12 2011: 16-19

The mechanochemical activation study of Tsagaan-tsav zeolite

Characterisation of mechanochemically activated Tsagaan-tsav zeolite has been performed. Tsagaan-tsav zeolite has been activated with a vibration mill for 2, 3, 5, 10 and 20 minutes. Ball to powder ratios were varied 1:10, 1:20, 1:50 and 1:100. Efficiency of milling determined based on amorphisation rate and cation exchange capacity changes. The highest efficiency was obtained for zeolite milled with ball to powder ratio of 100. Structural characterisation was performed with XRD, SEM, BET and particle size analyzer. Mechanochemical activation improves cation exchange capacity of natural zeolite.DOI: http://dx.doi.org/10.5564/mjc.v12i0.181 Mongolian Journal of Chemistry Vol.12 2011: 98-101

On enhancement of cooperation between universities for implementation of the program «Sustainable development–2030»

The article is focused on one of the pressing issues of our time – the international training of qualified personnel in higher education institutions with the aim of developing a stable economic system of the state, the main elements of which are interrelated stages of economic activity (exploration, prospecting, extraction, processing, and use of mineral resources). The question of the contribution and role of universities of different countries cooperating in the sphere of sustainable development of this sector is considered. The necessity of practical solution of this task for the implementation of UNESCO's program «Sustainable Development – 2030» is determined. In this relation, the concept of «sustainable development», its philosophical, scientific-theoretical and cultural aspects are considered, the special significance of the connection between the sustainable development of society and its individual fragments with modern education is emphasized. It is stated that education, in the context of sustainable development, should be anticipating, advancing and open. Given the current trends in higher education, it is possible to mention the work carried out by the Mining Institute of the Mongolian State University of Science and Technology in the direction of international cooperation

On polynomial equation rings and radicals

The notion of n-polynomial equation ring, for an arbitrary but fixed positive integer n, is introduced. A ring A is called an n- polynomial equation ring if γ(A[Xn ]) = γ(A)[ Xn ], for all radicals γ. If this equation holds for all hereditary radicals γ, then A is said to be a hereditary n-polynomial equation ring. Various characterizations of these rings are provided. It is shown that, for any ring A, the zero-ring on the additive group of A is an n- polynomial equation ring and that any Baer radical ring is a hereditary n- polynomial equation ring. New radicals based on these notions are introduced, one of which is a special radical with a polynomially extensible semisimple class. Mathematics Subject Classification (2010): 16N80. &nbsp

On polynomial equation rings and radicals

The notion of n-polynomial equation ring, for an arbitrary but fixed positive integer n, is introduced. A ring A is called an n- polynomial equation ring if γ(A[Xn]) = γ(A)[ Xn], for all radicals γ. If this equation holds for all hereditary radicals γ, then A is said to be a hereditary n-polynomial equation ring. Various characterizations of these rings are provided. It is shown that, for any ring A, the zero-ring on the additive group of A is an n- polynomial equation ring and that any Baer radical ring is a hereditary n- polynomial equation ring. New radicals based on these notions are introduced, one of which is a special radical with a polynomially extensible semisimple class.info:eu-repo/semantics/publishedVersio

The effect of different watering regimes and fertilizer addition on the growth of tree species used to afforest the semi-arid steppe of Mongolia

The environmental restoration of the semi-arid steppe of Mongolia is currently being addressed by creating new plantations able to protect the soil from the advancement of desertification and to improve the economy of the population living there. The success of these interventions relies on a high survival rate and good long-term growth performance of the transplanted trees. In the present work we analyzed stem height and root collar diameter (RCD) over 10 years for two native tree species (Populus sibirica and Ulmus pumila) grown with different water regimes and fertilizers. The investigated duration is sufficiently long to provide a reliable indication of the adaptation of these tree species to the steppe\u2019s harsh environmental conditions. Results suggest that both species could be used for environmental restoration projects, although P. sibirica requires the support of additional irrigation to achieve the best growth performance. U. pumila, on the other hand, shows good growth performance even with rainfall as the only water source. However, the higher water use by P. sibirica trees seems to be compensated by a more rapid ground cover compared to U. pumila. The addition of fertilizers to the soil before transplantation does not improve the growth performance of either species

Vitamin D supplements for fracture prevention in schoolchildren in Mongolia: analysis of secondary outcomes from a multicentre, double-blind, randomised, placebo-controlled trial.

BACKGROUND: Vitamin D supplementation has been shown to increase total hip areal bone mineral density in healthy children and adolescents. We aimed to investigate whether supplementing schoolchildren living in Mongolia with weekly vitamin D3 for 3 years affected fracture risk. METHODS: We did a multicentre, double-blind, randomised, placebo-controlled trial across 18 public schools in Ulaanbaatar, Mongolia. Schoolchildren were eligible if they were aged 6-13 years at screening, had a negative QuantiFERON-TB Gold In-tube assay (QFT) result, were not hypersensitive to vitamin D or immunocompromised, did not use vitamin D supplements, did not have clinical signs of rickets, and had no intention of leaving Ulaanbaatar within 3 years. Participants were randomly assigned (1:1) to receive either vitamin D (oral dose of 14 000 international units [IU] vitamin D3, once per week) or placebo for 3 years using permuted block randomisation stratified by school of attendance. Participants, care providers, and all trial staff were masked to group assignment during the intervention. Prespecified secondary outcomes were incidence of fractures and adverse events, ascertained using questionnaires. The fracture and safety analyses included participants who completed at least one follow-up fracture questionnaire. We estimated adjusted risk ratios (RRs) and 95% CIs using generalised linear models with binomial distribution and a log link function with adjustment for school of attendance. The trial is registered with ClinicalTrials.gov, NCT02276755, and the intervention ended in May, 2019. FINDINGS: Between Sept 2, 2015, and March 20, 2017, 11 475 children were invited to participate in the study and 8851 were recruited and randomly assigned to receive either vitamin D (n=4418) or placebo (n=4433). 8348 participants were included in the fracture and safety analyses (4176 [94·5%] in the vitamin D group and 4172 [94·1%] in the placebo group). Of these, 4125 (49·4%) were female, 4223 (50·6%) were male, and 7701 (92·2%) were of Khalkh ancestry. Median age was 9·2 years (IQR 8·0-10·7) and 7975 (95·5%) participants had baseline serum 25-hydroxyvitamin D concentrations less than 50 nmol/L. During a median follow-up of 3·0 years (IQR 2·9-3·1), 268 (6·4%) participants in the vitamin D group and 253 (6·1%) in the placebo group reported one or more fractures (adjusted RR 1·10, 95% CI 0·93-1·29; p=0·27). Incidence of adverse events did not differ between study groups. INTERPRETATION: Oral vitamin D supplementation at a dose of 14 000 IU/week for 3 years was safe, but did not influence fracture risk in schoolchildren living in Mongolia who had a high baseline prevalence of vitamin D deficiency. FUNDING: US National Institutes of Health