• The Korean Journal of Health Service Management
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• 제11권4호
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• pp.145-155
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• 2017

Objectives : To investigate the factors affecting bone mineral density in across stratified postmenopausal ages. Methods : Data from 1,698 subjects who completed the 2010-2011 National Health and Nutrition Survey were analyzed using SPSS Statistics 21.0 The $x^2$ test and one way (ANOVA) were used to verify the relationship between general characteristics and health behaviors and the prevalence of osteoporosis. Logistic regression analysis was used to verify the factors Influencing bone mineral density. Results : The bone mineral density distribution was the highest among those with osteopenia, with proportions of 21.8% in healthy subjects, 58.1% in osteopenia, and 20.0% in those with osteoporosis. The distribution of osteoporosis by age group was 5.2% among subjects in their 50s, 15.4% among those in their 60s, and 42.4% among those in their 70s. In multivariate logistic regression analysis, the prevalence of osteoporosis according to ages was significantly correlated with age, educational level, body mass index(BMI), and parity 4 of more than 1-2 babies. Conclusions : Although age is an uncontrollable factor in the prevention of osteoporosis, educational level and BMI are correctable factors to maintain bone mineral density. There is a need to maintain healthy BMI and expand osteoporosis prevention education.

• Journal of Ceramic Processing Research
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• 제19권5호
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• pp.428-433
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• 2018

In this study, using the pilot plant activation system, the activated cement has been manufactured and then applied to the manufacturing process of mineral hydrate insulating material. The fineness of the activated cement is controlled at $5,000cm^2/g$ and $7,500cm^2/g$ and the features of mineral hydrate insulating material, using OPC and the activated cement for each degree of fineness, has been analyzed. As the result of analyzing the crystal habit of the manufactured mineral hydrate insulting material, it is analyzed that the main crystal phase of specimen is tobermorite and some quartz peak has been detected. As the degree of fineness of the activated cement increases, the height of bubble of slurry increases as well, whereas the tendency for the density character to decrease has been detected. Along with it, as the density character decreases, the compression strength has decreases, whereas the tendency for the thermal characteristic to increases has been detected. The main features of mineral hydrate insulating material, using the activated cement with the fineness of $7,500cm^2/g$, the compression strength of 0.36 MPa, and the thermal conductivity of $0.044W/m{\cdot}K$, presents the excellent features as insulation.

• Geomechanics and Engineering
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• 제37권3호
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• pp.279-291
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• 2024

The "Korea Institute of Geoscience and Mineral (KIGAM) Quake" is a web-based open platform developed for publicly serving seismological data from 61 stations operated by KIGAM in Korea. The service provides meta-information related to observatory sites, sensors, and recorders necessary for utilizing the seismological data, as well as mainly observed continuous and strong-motion waveforms. The data is available through both the web and International Federation of Digital Seismograph Networks (FDSN) web services (open API), a unified data-providing interface in seismology. The platform aims to strengthen its open nature by offering a signal processing function for strong ground motions that can be controlled by user requests. The processed results can be downloaded in ASCII format, designed to meet the increased demands and accessibility in the earthquake engineering field. The platform also offers earthquake research information produced by KIGAM, such as recent major earthquake source information and academic annual report of earthquakes. Additionally, a site flat file was constructed for the geotechnical characteristics of 61 KIGAM station (KGNET) sites based on direct investigations and estimations.

• Journal of the Korea Institute of Military Science and Technology
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• 제27권3호
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• pp.338-345
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• 2024

Magnetic anomaly signals from the ferromagnetic targets such as ships in the sea are measured by drone-based magnetic anomaly detection. A quantum magnetometer is suspended from the drone by 4 strings. Flight altitude and speed of drone are 100 m and 5 m/s, respectively. We obtain magnetic anomaly signals of few nT from the ships clearly. We analyze the signal characteristics by the ferromagnetic target through simulation using COMSOL multiphysics.

• Korean Journal of Mineralogy and Petrology
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• 제33권2호
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• pp.129-141
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• 2020

The Mogok metamorphic belt is a highland area mainly consisting of Archean crystalline rocks, where many ruby mines were distributed in the past, and jewelry has been identified in its alluvium as placer deposit. Minerals that are usually identified with ruby include spinel, garnet, and rubellite. The conglomerates that form the alluvium in which jewelry is found mainly consist of gneiss and clastic pegmatites. In Singu, Mogok, and Momeik areas, a number of pegmatites containing jewelry are distributed in the intrusions of Mogok metamorphic rocks, diorites, and granites. In Singu pegmatites, rubellite, goshenite, and blue and violet apatite occur as gems. In Momeik pegmatites, mushroom-type rubellite, petalite, hambergite, pollucite, and aquamarine can be found. In Mogok pegmatites, topaz, aquamarine, goshenite, and herderite occur are present.

• Journal of Soil and Groundwater Environment
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• 제23권2호
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• pp.23-29
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• 2018

This study explored secondary effects of the residual hydrofluoric acid (HF) after a hypothetical acid spill accident by investigating the long-term dissolution of minerals and leaching of pre-existing arsenic (As) from two soil samples (i.e., KBS and KBM) through batch and column experiments. An increase in the HF concentration in both soil samples resulted in a dramatic increase in the release of major cations, especially Si. However, the amounts of mineral dissolved were dependent on the soil type and mineral characteristics. Compared to the KBM soil, relatively more Ca, Mg and Si were dissolved from the KBS soil. The column experiment showed that the long-term dissolution rates of the minerals are closely associated with the acid buffering capacity of the two soils. The KBM soil had relatively higher effluent pH values compared to the KBS soil. Also, more As was leached from the KBM soil, with a more amorphous hydrous oxide-bound As fraction. These results suggest that the potential of heavy metal leaching by the residual acid after an acid spill will be influenced by heavy metal speciation and mineral structure in the affected soil.

• Economic and Environmental Geology
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• 제53권6호
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• pp.743-753
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• 2020

This study analyzed heavy metal concentration, mineral composition, and spectral characteristics of heavy metal contaminated soil samples of cropland and rice field located in downstream of abandoned Okdong coal mine. X-ray fluorescence analysis detected heavy metal elements including cadmium, copper, arsenic, lead, zinc and nickel in the soils. Both cropland and rice field samples were severely contaminated with arsenic showing higher concentration over the concerned standard. The pollution index of cropland samples was higher than that of rice field samples. X-ray powder diffraction analysis identified that the mineral composition of cropland and rice field samples is similar with quartz, calcite, kaolinite, illite, smectite, magnetite and hematite. The range of organic matter content were more widely distributed in cropland samples. The spectral analysis showed that the reflectance spectra and the absorption features of cropland and rice field samples were alike. The absorption features that appeared near 490nm and 900nm were attributed to the ferric iron, and clay minerals such as kaolinite and smectite caused the absorption features at 1410nm, 1910nm and 2200nm. The reflectance of the soil spectral decreased with an increase in organic content. The absorption depths of both types of soil samples decreased with higher organic matter content at 490nm and 1916nm as well as higher heavy metal concentration.

• Journal of Korean society of Dental Hygiene
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• 제10권6호
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• pp.1121-1128
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• 2010

Objective : This study was to survey the differences of bone mineral density and oral health-related characteristics according to smoking status. Methods : The data for this study were collected by Oral health-related questionnaire and BMD measurements of 20s adults(205) who were using gym in D college areas from July 5th to 9th, 2010. Results : 1. There were a significant difference of 65.4 % of male in smoker group, 59.8% of women in non smoker group(p=0.000). 2. There were a significant difference in subjective oral symptoms among yellow teeth(p=0.000). 3. There were no difference in the T-score of DMB according to smoking. Conclusion : According to the study on smoking, only subjective oral symptoms were shown while the differences at bone mineral density were insignificant. Above findings suggest that further study about the expanding the number and ages of the subjects, smoking, BMD, and oral health related studies is necessary.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제28권6호
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• pp.52-59
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• 2014

This paper deals with the effect of decomposition products which occur in breakdown of mineral oil, on the insulation characteristics of its oil. Breakdown tests in the oil were conducted by the proposed experimental methods under a quasi-uniform field and AC HV (60Hz). The breakdown voltage in the oil shows characteristics of dispersion from successive breakdowns and, it is found that there are three patterns of the decomposition products behavior at the process of breakdown progress in the oil. Finally, the breakdown voltage dispersion in the oil can be described in detail based on the behavior patterns of the decomposition products and its diffusion time.

• Journal of Soil and Groundwater Environment
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• 제24권1호
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• pp.1-9
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• 2019

This study presents a technical perspective to the fate characteristics of phenol and m-cresol, which represent some of the most common organic chemicals found in chemical spill accidents, and likely to persist in soil and groundwater due to their highly stable physicochemical properties. Some cases of domestic and foreign chemical accidents linked to phenol and m-cresol contamination were compiled. Due to their low organic carbon-water partitioning coefficient (Koc), phenol and m-cresol tend to migrate into groundwater and remained as dissolved phase. On the other hands, phenol and m-cresol can be readily decomposed by microbes in soil and groundwater under appropriate conditions. Therefore, the fate characteristics of these chemicals are highly contingent on environmental conditions. Thus, if a great quantity of leakage is occurred by chemical accidents, the up-to-date and correct information about fate characteristics taking into account both the chemical and environmental conditions is greatly needed to minimized the potential hazards from these chemicals.