• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.917-920
• /
• 2001

Effects of addition of manganese and final reduction on segregation behavior of sulfur and final mangetic induction during final annealing have been investigated in the 300 ppm sulfur-contained 3% silicon-iron alloy strips with or without manganese. At the same concentration of sulfur, lower final reduction is favorable for final Goss texture. This is because the probability that the initial Goss grains survive under the highly segregated sulfur atmosphere and grow selectively within the segregated sulfur-free time range becomes higher. In the case of 3% silicon-iron with manganese, much lower magnetic induction was obtained, although the weak final reduction of 30% is given to the alloy, comparative to the 40%. This is because MnS particles acted as an reducer in the primary grain size.

• Journal of Environmental Science International
• /
• v.17 no.9
• /
• pp.943-947
• /
• 2008

For the purpose of safety identification, the concentrations of heavy metals in seaweeds collected from Busan Gijang coastal area were investigated. The average concentration of metals had a level of as high as the order of manganese (2.76 ppm)>zinc(2.11 ppm)>copper(0.59 ppm)>arsenic (0.092 ppm)>lead(0.06 ppm)> mercury(0.03 ppm)>cadmium(0.026 ppm). The contents of manganese and zinc were highly detected from P. elliptica, copper and mercury from agar, cadmium from sea mustard and arsenic from wild sea mustard, respectively. The metal contents of seaweeds varied with kinds of samples, but high level for the safety can be found in these samples. Because P. elliptica had shown a clear selectivity for both manganese and zinc, this seaweed could be useful as a bioindicator for these two metal pollution.

• Journal of Environmental Health Sciences
• /
• v.22 no.4
• /
• pp.1-9
• /
• 1996

Experiments have been made to test the practical feasibility of using calcined manganese ore to desulfurize hot reducing gas. In this study, the effects of particle size of sorbents, temperature of sulfidation, flow rate and sorbent characteristics on the $H_2S$ removal efficiency of calcined manganese ore were investigated. Experimental results showed that the removal efficiency of $H_2S$ was optimum when the temperature was about 800$\circ$C and that the smaller particle size the higher the $H_2S$ removal efficiency. When the temperature was above 800$\circ$C, the reactivity of sorbent has lowered because agglomeration of sorbent increased intraparticle transport resistance, and this phenomenon was confirmed by SEM photographs. As the temperature increases, capacity for the $H_2S$ removal was increased but the equilibrium concentration of $H_2S$ was not affective.

• Journal of Environmental Health Sciences
• /
• v.1 no.1
• /
• pp.41-45
• /
• 1974

A study was carried out to determine the content of Mn and Cr in the ground water in Seoul area, where municipal water supply system was not installed, from Nov. 1 to Nov. 30, 1973. In this study, authors examined the hardness, pH, water temperature and Cl ion to investigate the general conditions of the ground water. For this study, samples were collected from 46 wells which were located in outpart of Seoul city, and Mn and Cr were determined with the Spectronic-20. The following results were obtained: 1) Average value of the ground water conditions of the wells were 13.3$\circ$C in temperature, pH 6.3, hardness 159 ppm and Cl ion 41 ppm. 2) In the manganese concentration, the highest area was Yeongdeungpo-Ku(0.318 ppm), while the lowest area was Sungbuk-Ku(0.065 ppm) and the mean concentration of the whole district was 0.196 ppm. 3) In the chrome concentration, the highest area was Yeongdeungpo-Ku(0.031 ppm), while the lowest area was Dobong-Ku (trace) and the mean concentration of the whole district was 0.012 ppm.

• Journal of Environmental Health Sciences
• /
• v.46 no.3
• /
• pp.267-275
• /
• 2020

Objectives: The causes of dementia have been reported in various ways, but there has been little research on the interrelationship between heavy metals and dementia, and the results also show little consistency. Therefore, it is imperative to compare the levels of heavy metal exposure between the dementia-suffering group and a control group to confirm the correlation between the level of heavy metal exposure and the likelihood of dementia. Methods: In order to assess the dementia level of the elderly, the Global Deterioration Scale (GDS) and Mini Mental State Examination (MMSE) were applied. To analyze the concentration of heavy metals in the blood, blood was collected from the veins of study subjects and measured using Inductively Coupled Plasma-mass spectrometry (ICP-MS). Results: There was a statistically significant correlation between lead and manganese concentrations in the blood and the MMSE and GDS. It was found that there was a statistically significant correlation between cadmium concentration in the blood and the GDS, but the MMSE was less relevant. It was found that the blood mercury concentration and the MMSE and GDS were less relevant. The lead concentration in the blood was 0.95±0.74 ㎍/dL in the dementia patient group and 0.33±0.22 ㎍/dL in the normal group, while cadmium was 0.69±0.37 ㎍/L in the dementia group and 0.18±0.10 ㎍/L in the normal group. Mercury was 0.81±0.31 ㎍/L in the dementia group and 1.16±0.80 ㎍/L in the normal group. Manganese was 6.83±2.01 ㎍/L in the dementia group and 4.78±1.59 ㎍/L in the normal group. All of these show statistically significant differences. Conclusions: As the concentration of lead, cadmium and manganese in the blood increases, the MMSE scores and GDS scores were found to worsen, and it was confirmed that there is a correlation between heavy metal exposure and cognitive degradation.

• Journal of the Korean Data and Information Science Society
• /
• v.27 no.3
• /
• pp.577-586
• /
• 2016

Hazardous air pollution caused by heavy metals in the air is at a serious level. Although manganese(Mn), one of the heavy metals, is a non-carcinogenic substance, it has a harmful influence on the human body. It is partially measured because automatic monitoring technologies have not yet be fully established. We introduced a statistical model for the daily concentration of manganese. Incorporating a linkage between Mn and meteorology, the proposed model is formulated in way to identify meteorological effects and to allow for seasonal trends, enabling not only accurate measurement of manganese concentration, but also information about the evaluation on a Hazard Quotient (non-cancer risk).

• Journal of Korean Society for Atmospheric Environment
• /
• v.16 no.4
• /
• pp.399-408
• /
• 2000

This study evaluated the SO2 adsorption characteristics using a continous moving bed system. Natural manganese oxide (NMO) reaction condition such as L/D the starting time of the NMO feed, feed rate, and flow rate of simulated flue gas, and NMO size were tested. The results showed that optimum L/D was 1.0 in this moving bed system. The higher the feeding rate was the higher the SO2 removal efficiency was and the higher the flow rate of simulated flue gas was the shorter the time to reach the euqilibirum concentration was. The final SO2 con-centration when it reaches the equilibrium concentration was not affected by the starting time of the NMO feed.

• Journal of Plant Biology
• /
• v.10 no.3_4
• /
• pp.4-9
• /
• 1967

The aim of present study is to elucidate the effects of manganese and aluminium ions on the germination and seedling growth of Pinus banksiana and Alnus tinctoria and to estimate the limiting level of those ions in the cultivated soils. The rate of germination of Pinus banksiana was increased under the relatively low concentration of Mn and Al (100 p.p.m), however, the germinating activity was not affected. High concentration over 110 p.p.m. of Mn and Al was related to the reduced percentage of germination and seedling growth of Pinus banksiana and Alnus tinctoria. Soils sampled from various parts of Korea contained Mn as much as high level that would be harmful for the seedling growth of Pinus banksiana and Alnus tinctoria.

• Proceedings of the Petrological Society of Korea Conference
• /
• 1999.06a
• /
• pp.25-29
• /
• 1999

Manganese (Mn) oxides in soils and sediments differ in structure and composition. The influence of that diversity on the chromium (Cr) oxidation is the subject of this report. Oxidation of Cr(III) to Cr(VI) by coarse clay size Mn oxides (synthetic pyrolusite and natural lithiophorite, todorokite, and bimessite) was studied. Chromium oxidation by Mn oxides was initially fast and followed by a slow reaction. More Cr was oxidized by the Mn oxides at lower pH and higher initial Cr(III) concentration in solution. Birnessite had the highest chromium oxidation capacity per unit external surface area (COCUESA) and lithiophorite had the lowest COCUESA. The kinetics of Cr oxidation and COCUESA of Mn oixdes were apparently controlled by reactivity of surface Mn, mineralogy, and solution properties (pH and Cr(III) concentration).

• Journal of Microbiology and Biotechnology
• /
• v.9 no.6
• /
• pp.732-736
• /
• 1999

The superoxide dismutase (SOD) in Lactococcus lactis was measured quantitatively and qualitatively under various culture conditions. The L. lactis SOD was induced by oxidative stress. As the concentration of paraquat to produce superoxide radicals increased, the growth of L. lactis decreased with concomitant increase of SOD activity. The SOD activity was found to be growth-phase dependent: when aerobically grown cells entered to the stationary phase, the activity increased gradually until the late stationary phase. From inhibition studies, L. lactis SOD was found to be insensitive to KCN and $H_2O_2$ which are known to inhibit Cu/ZnSOD and FeSOD, respectively. Moreover, as the concentration of manganese in the medium increased, the activity of SOD also increased. These data strongly suggested that L. lactis possessed a single manganese-containing SOD (MnSOD). Finally, a putative sod gene fragment of 510 bp was identified in L. lactis using a polymerase chain reaction (PCR) with degenerate primers designed from the deduced DNA sequences of known SOD genes.