Gas Sensing Performance of Multiple-shell Hollow Silver and Hematite Composite Microspheres

In this report, multiple-shell hollow silver and hematite composite microsphere has been prepared by using carbonaceous saccharide microsphere as template. The products were characterized by X-ray powder diffraction (XRD), scanning electronic microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). The core size and shell thickness of hollow spheres obtained can be manipulated by changing the concentration of metal salt. The unique multiple-shell hollow silver and hematite composite microspheres may be potentially used as gas-sensor materials for detecting various toxic gases.DOI: http://dx.doi.org/10.5564/mjc.v12i0.163 Mongolian Journal of Chemistry Vol.12 2011: 7-1

Implementation of distance technologies in Euro-Asian universities during the COVID-19 pandemic

The authors of the chapter Implementation of distance technologies in Euro- Asian universities during the COVID-19 pandemic are Sergey Kokhan, Ariunsanaa Byambaa, Elena Romanova, Batbaatar Gunchin and Witold Kowalski. The aim of the study is to conduct a comparative analysis of the organization of the transition to the distance education (DE) during the coronavirus period in the universities of Mongolia and Russia and to identify problems that need to be addressed by the administration of universities and academic teaching staff. The study object are students of the Mongolian National University of Medical Sciences (MNUMS, Mongolia) and Trans-Baikal State University (TBSU, Russia). The main research method was questioning. The total number of respondents was 271 people. The research carried out at the universities in Mongolia and Russia showed a certain difference in approaches to solving alternative problems which were connected with the transition to DE and the identification of problems among students of the two countries. In the period of pandemic, the transition from the traditional system to DE was the only correct way to save education all over the world. Nevertheless, the emergency transition showed both its positive aspects and the problems of the system. It is possible to solve these problems but they can only be solved with the interaction of all interested sides, starting with state level, the administration of universities, the teaching staff, and ending with student youth, the consumers of DE.Collection name: LIBRARY "PEDAGOGICAL THEORY AND PRACTICE" 5

Molecular Modeling of Acidic Treated PSTM-3T Polymer for Removal of Heavy Metal Ions by Experimental and Computational Studies

The synthesized poly[N,N′-bis(3-silsesquioxanilpropyl)-thiocarbamide] (PSTM-3T) was used and the surface morphology and microstructure of it were analyzed by scanning electron microscopy with energy dispersive spectrometer (SEM/EDS). The molecular structure change of the PSTM-3T polymer of the PSTM-3T after treatment by acidic solution with different pHs was revealed using FT-IR experiments and ab initio calculations with density functional theory method. The sorption efficiency of the heavy metal ions depends on the molecular structure change of PSTM-3T after treatment of different pH aqueous solutions. After the treatment of acidic solution (pH = 2) of PSTM-3T, the polymer formed the tautomer state to increase the sorption efficiency for chromate ion. For the increment of pH value for acidic solution, the PSTM-3T polymer was dissociated to increase the sorption efficiency for copper ion

Three-year long source apportionment study of airborne particles in Ulaanbaatar using X-ray fluorescence and positive matrix factorization

The capital city of Mongolia, Ulaanbaatar, suffers from high levels of pollution due to excessive airborne particulate matter (APM). A lack of systematic data for the region has inspired investigation into the type, origin and seasonal variations of this pollution, the effects of meteorological conditions and even the time-dependence of anthropogenic sources. This work reports source apportionment results from a large data set of 184 samples each of fine (PM2.5) and coarse (PM2.5-10) fraction atmospheric PM collected over a three-year period (2014–2016) in Ulaanbaatar, Mongolia. Positive Matrix Factorization (PMF) was applied using the concentrations of 16 elements measured by an energy dispersive X-ray fluorescence spectrometer along with the black carbon content measured by a reflectometer as input data. The PMF results revealed that whereas mixed sources dominate the coarse fraction, soil and traffic sources are the principle contributors to the fine fraction. The source profiles and the seasonal variations of their contributions indicate that fly ash emanating from coal combustion mixes with traffic emissions and resuspended soil, resulting in variable chemical source profiles. Four sources were identified for both fractions, namely, soil, coal combustion, traffic and oil combustion, which respectively contributed 35%, 16%, 41% and 8% to the coarse fraction and 31%, 27%, 31% and 11% to the fine fraction. Additionally, the probable source contributions from long-range transport events were assessed via concentration-weighted trajectory analysis

Prevalence and Determinants of QuantiFERON-Diagnosed Tuberculosis Infection in 9810 Mongolian Schoolchildren.

BACKGROUND: There is controversy regarding the potential influence of vitamin D deficiency, exposure to environmental tobacco smoke, BCG vaccination, season, and body habitus on susceptibility to Mycobacterium tuberculosis (MTB) infection. METHODS: We conducted a cross-sectional analysis to identify determinants of a positive QuantiFERON-TB Gold (QFT) assay result in children aged 6-13 years attending 18 schools in Ulaanbaatar, Mongolia. Data relating to potential risk factors for MTB infection were collected by questionnaire, physical examination, and determination of serum 25-hydroxyvitamin D (25[OH]D) concentrations. Risk ratios (RRs) were calculated with adjustment for potential confounders, and population attributable fractions (PAFs) were calculated for modifiable risk factors identified. RESULTS: Nine hundred forty-six of 9810 (9.6%) participants had a positive QFT result. QFT positivity was independently associated with household exposure to pulmonary tuberculosis (adjusted RR [aRR], 4.75 [95% confidence interval {CI}, 4.13-5.46, P < .001]; PAF, 13.1% [95% CI, 11.1%-15.0%]), vitamin D deficiency (aRR, 1.23 [95% CI, 1.08-1.40], P = .002; PAF, 5.7% [95% CI, 1.9%-9.3%]), exposure to environmental tobacco smoke (1 indoor smoker, aRR, 1.19 [95% CI, 1.04-1.35]; ≥2 indoor smokers, aRR, 1.30 [95% CI, 1.02-1.64]; P for trend = .006; PAF, 7.2% [95% CI, 2.2%-12.0%]), and increasing age (aRR per additional year, 1.14 [95% CI, 1.10-1.19], P < .001). No statistically significant independent association was seen for presence of a BCG scar, season of sampling, or body mass index. CONCLUSIONS: Vitamin D deficiency and exposure to environmental tobacco smoke are potentially modifiable risk factors for MTB infection

Survival, CD4 T lymphocyte count recovery and immune reconstitution pattern during the first-line combination antiretroviral therapy in patients with HIV-1 infection in Mongolia.

Mongolia has a low incidence of human immunodeficiency virus (HIV) infection, with 281 cases reported at the end of 2019 and an estimated incidence rate of 50 cells/μL indicated CD4 T cell count recovery, and a cell count of ≥500 cells/μL in patients with a baseline cell count of 500 cells/μL in 95 of 145 (65.5%) patients with a baseline cell count of <500 cells/μL after 36 months of ART. The baseline CD4 T cell count was found to be a sensitive indicator for immune reconstitution. An advanced pretreatment clinical stage of HIV infection (as classified by the WHO classification), a low CD4 T cell count in the peripheral blood, and a high viral load before the initiation of the first-line ART accurately predicted survival, CD4 T cell count recovery, and immune reconstitution in Mongolian patients with HIV/AIDS

Implementation of the Methodology of Coupled Modelling of Aerodynamics and Strength to Determine the Onset Speed of the Bending-Torsional Flutter of the Wing Console

Time-domain motion simulations using the averaged Navier-Stokes Euler and Reynolds equations were performed for an AGARD 445.6 wing in transonic flow. These simulations were compared with experimental results as well as with the solution in the frequency domain using a method based on the fast Fourier transform. The model matches in frequencies and shapes with experiment

Correction: Survival, CD4 T lymphocyte count recovery and immune reconstitution pattern during the first-line combination antiretroviral therapy in patients with HIV-1 infection in Mongolia.

[This corrects the article DOI: 10.1371/journal.pone.0247929.]