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Road Dust Reduction by Filter Installed on Public Bus
(2023) Odbileg Norovrinchen1; Sungchil Lee; Baljinnyam Guntevsuren
In this research, to minimize road dust in the air which has a harmful effect on public health a new filtering device prototype was proposed. The proposed device was designed to be mounted on public buses. The best location of the device on the public bus was found from the airflow dynamic analysis around a public bus which runs in Ulaanbaatar city. It was found from the numerical simulation, the air flow around the bus is perturbed at the rear side of the bus. It produces vortices at the rear side of the bus. Considering the power supply to the filtering device, the engine room at the rear side of the bus was chosen as an optimal location for the device. The device was mounted on a public bus and had collected road dust for two weeks. From the test results, it is concluded that the proposed device has a very high performance in collecting road dust with minimum efforts.
Fatigue Strength Estimation Based on the Maximum Likelihood Method
(2023) Sungchil Lee; Odbileg Norovrinchen; Chinguunbileg Sumiyadorj
Fatigue strength is one of the core principles for designing mechanical components. It has been a constant concern for engineers, as mechanical failure occurs due to loading exceeding the fatigue strength. This concern has led to a necessity to develop new approaches to estimate the reliability of mechanical components. The conventional method that is used to test fatigue strength is the staircase method. However, the staircase method’s ability to calculate fatigue strength is potentially unreliable. The bias and scatter associated with fatigue testing shows the limitations of fatigue strength estimation when the staircase approach is used. The conventional methods of fatigue limit determination also have key flaws, in that they are subjective, time consuming, and costly. This research aims to develop a method that would reliably estimate the fatigue strength of materials, whilst using a lower amount of test results. The present study is intended to formulate and analyze a proposed method of estimating fatigue strength by utilizing a smaller number of tests. The aforementioned method that this paper aims to formulate, mainly focuses on a probabilistic estimation based on the Maximum Likelihood Procedure. The proposed method is applied to existing fatigue test data and its effectiveness is compared with other methods.
Advanced methods in processing deep-sea manganese nodules
(2024) Purev-Ochir Togtokhbaatar; Thomas Lütke; Peter Fröhlich; Martin Bertau
Deep Sea Manganese nodules are investigated by chemical leaching and solid-state chlorination (SSC) to explore a cheaper processing method. Mn nodules contain various essential elements of cobalt (Co), Nickel (Ni), Copper (Cu), Magnesium (Mg), and Zinc (Zn). The pulverized Mn nodule dissolved in Oxaline (1 oxalic acid + 1 choline chloride) completely within 30 min, and in Ethaline (1 Ethylene glycol + 1 choline chloride) within 72 hours. Also, diluted acids (1M H2SO4 and 1M HCl) leaching with reducing agents (H2O2 or C2H2O4) showed efficient dissolution rates. Furthermore, SSC was effective method to process Mn nodules in a presence of NH4Cl then processed nodules leached in diluted acids.
Mn dissolution rate can be ordered at 300 °C (~ 50 %), 600 °C (~ 90 %) without reducing agents. Also, these leaching experiments were carried out with reducing agents and those enhanced the Mn dissolution rate by significant amounts. Finally, leaching solutions processed by the electro winning Mn and Cu are successfully deposited on the electrodes.
Natural rehabilitation potential in two distinct mining areas in Mongolia
(2023) Oyun-Erdene Tsogtsaikhan; Gantuya Ganbat; Martin Knippertz
Soil erosion in Mongolia has intensified, and the general level of soil fertility has decreased. The effects of global warming, and human activities such as grazing pastureland, mining operation, intensification of agriculture, urbanization, and road damage are the main causes of soil cover degradation. Due to the ecosystem characteristics of the geographical landlocked location within continental harsh, arid climatic conditions, there is clearly a different identification requirement in rehabilitation potential of mining areas. So, it is necessary to dig in to differentiate the possible rehabilitation characteristics on the most suitable ecosystems. And discrimination of the potentiality by the ecosystem and location makes how to achieve optimized mining rehabilitation results.
In this work, the focus is to concentrate on the natural healing process and weigh into potentiality using pyramid concept [1]. Study area and soil characteristics are considered on 2 distinct mining areas located in 2 different ecozones of Mongolian, one is in sub northern area, Ecozone III, which covers both sandy Katsanoses soil and gravelly sandy kastanozem soil. The other comparison study area is Ecozone VI, which within the desert zone the soil specially forms in gravelly and sandy features, and the vegetation becomes scarce with its both species and biomass due to its hot, dry characteristics. Kastanozem soil has more fertile components and thicker humus layer than the desert gravelly and sandy features. Natural features consist of climatological features (precipitation, temperature, wind), soil types and vegetation index data were collected and analyzed using ArcGIS software. These mining areas followed up with verification areas weighted in Khuvsgul and Southgobi areas appointed 180 and 120 points respectively. However, the potential scores on rehabilitation expenses explain active regions that the chance of adjustable value on those planned rehabilitation budget, where sustaining the soil rehabilitation stick into long term natural healing process.
These concludes that the pyramid concept should be applied to the other areas of Mongolian mining sites to enable natural rehabilitation potentiality into long term, sustainable mining rehabilitation plan.
Road Dust Reduction by Filter Installed on Public Bus
(2023) Odbileg Norovrinchen; Sungchil Lee; Baljinnyam Guntevsuren
In this research, to minimize road dust in the air which has a harmful effect on public health a new filtering device prototype was proposed. The proposed device was designed to be mounted on public buses. The best location of the device on the public bus was found from the airflow dynamic analysis around a public bus which runs in Ulaanbaatar city. It was found from the numerical simulation, the air flow around the bus is perturbed at the rear side of the bus. It produces vortices at the rear side of the bus. Considering the power supply to the filtering device, the engine room at the rear side of the bus was chosen as an optimal location for the device. The device was mounted on a public bus and had collected road dust for two weeks. From the test results, it is concluded that the proposed device has a very high performance in collecting road dust with minimum efforts.