• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.281-282
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• 2009

The purpose of this experimental research is to investigate the influence of mineral admixtures on the resistance to acid and sulfate. For this purpose, concrete specimens with types of mineral admixtures such as ground granulated blast-furnace slag, fly ash, and silica fume were made for water-binder ratios of 32% and 43%. It was observed from the test result that the resistance against acid and sulfate of the concretes containing mineral admixtures were much better than the case of plain concrete from immersion tests of 182 days.

• Journal of the Korean Ceramic Society
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• v.53 no.2
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• pp.222-226
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• 2016

The synthesis of pure calcium carbonate nanocrystals was achieved using a simultaneous injection method to produce nano particles of uniform size. These were characterized using scanning electron microscopy and powder X-ray diffraction. The nano particles were needle-shaped aragonite polymorphs, approximately 100-200 nm in length. The aragonite polymorph of calcium carbonate was prepared using aqueous solutions of $CaCl_2$ and $Na_2CO_3$, which were injected simultaneously into double distilled water at $50^{\circ}C$ and then allowed to react for 1.5 h. The resulting whisker-type nano aragonite with high aspect ratio (30) is biocompatible and potentially suitable for applications in light weight plastics, as well as in the medical, pharmaceutical, cosmetic and paint industries.

• Journal of Energy Engineering
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• v.27 no.1
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• pp.51-58
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• 2018

In this paper, we reported that the influence of advanced functional mineral filler calcium carbonate ($CaCO_3$) extracted from oyster shell waste, which are rich mineral sources of $CaCO_3$. Oyster Shells, available in abundance, have no eminent use and are commonly regarded as waste. Their improper disposal causes a significant level of environmental concern and also results in a waste of natural resources. Recycling shell waste could potentially eliminate the disposal problem, and also turn an otherwise useless waste into high value added products. Oyster shell waste calcination process to produce pure lime (CaO) which have good anti-microbial property for waste water treatment and then focuses on its current applications to treat the coffee waste and its effluents for biological treatment and utilization as a fertilizers.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.2
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• pp.113-122
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• 2004

This study was conducted to examine the correlation among growth development, bone mineral density, and nutrient intakes in preschool children. A total of 62 preschool children measured the anthropometric characteristics and the bone mineral density of carpus using DEXA. The questionnaires categorized to determine health status, life style, dietary behaviors, and dietary intakes were filled out by children's mothers. The average ages of the study subjects were 62.4 months in boys and 62.1 months in girls. The birth height and weight of the subjects were 50.9 cm and 3.4 kg in boys and 50.3 cm and 3.3 kg in girls, respectively. The average height, weight, % body fat, and obesity index were 111.7 cm, 19.6 kg, 15.0%, -2.1% in boys and 109.4 cm, 18.7 kg, 17.5%, 0.2% in girls, respectively. The bone mineral density in carpus was 0.25 g/cm$^2$ in boys and 0.24 g/cm$^2$. In girls. Proportions of children having regular meals were 69.0%, 94.7%, and 69.0% for breakfast, lunch, and dinner, respectively. The major reasons for irregular meal were poor appetite and lack of time for breakfast and snacks for dinner. Most of the children(52.6%) had breakfast with the whole family together, and all the children had lunch and dinner with a part of the family. Most of the children answered they had snack more than once a day, and 64.3% had an unbalanced diet. The intakes of energy, calcium, iron, zinc, vitamin A, vitamin B$_1$, niacin, and vitamin C did not meet the Korean RDAs. Average bone mineral density in carpus was positively correlated to the body weight, the total body water, the lean body mass, and the obesity index, respectively(p＜0.01, p＜0.01, p＜0.01 and p＜0.01). The body weight, the total body water, and the lean body mass showed the significant negative correlations with the animal iron intake(p＜0.05, p＜0.01 and p＜0.01). The bone mineral density in the distal carpus was negatively correlated to the animal protein intake and the animal iron intake(p＜0.05 and p＜0.05). And the bone mineral density in the ultradis carpus and the average bone mineral density in the carpus were positively correlated to the plant calcium intake(p＜0.05 and p＜0.05). Therefore, more systematic studies to investigate the roles of protein, iron, and calcium in growth development of preschool children were required.

• Mineral and Industry
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• v.26
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• pp.1-12
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• 2013

In this study, an accelerated carbonation process was applied to stabilize hazardous heavy metals of industrial solid waste incineration (ISWI) bottom ash and fly ash, and to reduce $CO_2$ emissions. The most commonly used method to stabilize heavy metals is accelerated carbonation using a high water-to-solid ratio including oxidation and carbonation reactions as well as neutralization of the pH, dissolution, and precipitation and sorption. This process has been recognized as having a significant effect on the leaching of heavy metals in alkaline materials such as ISWI ash. The accelerated carbonation process with $CO_2$ absorption was investigated to confirm the leaching behavior of heavy metals contained in ISWI ash including fly and bottom ash. Only the temperature of the chamber at atmospheric pressure was varied and the $CO_2$ concentration was kept constant at 99% while the water-to-solid ratio (L/S) was set at 0.3 and $3.0dm^3/kg$. In the result, the concentration of leached heavy metals and pH value decreased with increasing carbonation reaction time whereas the bottom ash showed no effect. The mechanism of heavy metal-stabilization is supported by two findings during the carbonation reaction. First, the carbonation reaction is sufficient to decrease the pH and to form an insoluble heavy metal-material that contributes to a reduction of the leaching. Second, the adsorbent compound in the bottom ash controls the leaching of heavy metals; the calcite formed by the carbonation reaction has high affinity of heavy metals. In addition, approximately 5 kg/ton and 27 kg/ton $CO_2$ were sequestrated in ISWI bottom ash and fly ash after the carbonation reaction, respectively.

• Journal of environmental and Sanitary engineering
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• v.20 no.1 s.55
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• pp.55-63
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• 2005

Ground water samples of 275 were collected from Gapyeong county which it contained six-eup and myeon and analyzed for 12 mineral inorganics extending from March to October in 2004. Among the inorganics, Calcium, Magnesium, Sodium, Potassium, Copper and Zinc had more than $70\%$ of detection frequencies, which coincided with essential inorganics required by the human body. The average values of inorganic contents by sampling sites were insignificant. Fluorine contents of 8 samples, $2.9\%$ of 275 samples, exceeded KDWR, and it was considered to be affected by a base rock being made up granite and gneiss because there were not polluting sources around. It is necessary to find out relation between geological characteristics and mineral inorganics in ground water through the further investigation. Compared to noted concentrations of bottled water, inorganic minerals including Calcium, magnesium, Sodium and Potassium related to taste were fluent double in target samples and those average concentrations were 14.80, 3.80, 7.60, and $2.31\cal{mg/L}$ respectively.

• Journal of environmental and Sanitary engineering
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• v.19 no.4 s.54
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• pp.76-81
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• 2004

From September 1, 2003 to November 30, 2004, 20 mineral water wells were selected for some area in east Europe and the study on their water quality was analized. It revealed that mineral water contained considerable quantity of magnesium ions which helps the smooth activities of vascular muscles, nervous systems and protects skins from allergic reactions. It also lowers cholesterol level and contains high concentration of calcium ions which is one of the vital components of teeth and bone like phosphorus. Thus it is concluded that it is not qualified as boiler feed water as it has overall high degree of hardness by the presence of four times content of $Mg^{2+}\;and\;Ca^{2+}$.

• Journal of Soil and Groundwater Environment
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• v.17 no.3
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• pp.59-75
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• 2012

It is getting difficult to manage water resources in South Korea because more than half of annual precipitation is concentrated in the summer season and its intensity is getting severe due to global warming and climate change. Artificial recharge schemes can be a useful method to manage water resources in Korea adapting to climate change. Patent analysis enables us to prevent overlapping investment and to find out unoccupied technology. In this study, international patent trends and barriers of artificial recharge technology are analysed for patents of Korea, Japan, the United States and Europe. The four artificial recharge methods such as well recharge, surface infiltration, bank filtration and underground structures are classified as main class and the nine sub-technologies such as water intake, water treatment, injection wells, monitoring of groundwater flow, groundwater pumping, surface infiltration/soil aquifer treatment, radial collection well, iron/manganese treatment, and underground subsurface dam are classified as intermediate class. Water intake techniques are subdivided into five classifications. Total 1,281 of patents, searched by WIPS DB tool and selected after removing noisy patents, are analyzed quantitatively to evaluate application trends by year, applicant, country for each classified technologies and analyzed qualitatively to find out occupied and unoccupied technologies. It is expected that upcoming research and development project could be performed efficiently in that an avoidance plan for the similar patents and differentiation plan for the advancing patents are set up based on the quantitative and qualitative analysis results from this research.

• The Journal of Engineering Geology
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• v.18 no.3
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• pp.331-338
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• 2008

A new ground water sampler was developed and evaluated for target depth sampling under most rigorous field conditions. This new concept sampler comprises an air-cylinder, a hypodermic needle and a sampling bottle. Pressurized air or nitrogen gas can be used as a mechanical power source to operate the sampler. The air-cylinder is used to jab the hypodermic needle into the rubber cap of the sampling bottle. The hypodermic needle functions as a pathway to inject groundwater into the sampling bottle. Field test was conducted in a seawater intrusion monitoring well located at Handong district of Jeju Island. Water qualities in this well are periodically changed from the effects of sea water. Water sampling fir the same target depth in this well were tried at various times, and variations in electrical conductivity and pressure at the inside and outside of the sampler were measured using CTD divers. We found that the device could collect water samples only when it was actuated, and the pattern and range of variations in electrical conductivities and pressures measured at the inside and outside of the sampler were nearly identical. These results indicate that water samples using the sampler presented in this study represent correctly water qualities in which the samplings were made at a specific target depth in a well.

• Journal of Environmental Health Sciences
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• v.24 no.1
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• pp.87-97
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• 1998

This study was performed to investigate the Natural mineral water quality at 47 sites in Chonnam area, samples were collected spring, summer, fall, winter for a seasonal variation in 1996. The results obtained were summarized as follows 1. The mean of F, pH, HCO$_3$, NO$_3$ -N were 0.19 mg/l, 6. 9, 34.99 mg/l, 1.40 mg/l and those of Na, K, Ca, Mg were 12.1 mg/l, 1.2 mg/l, 7.7 mg/l, 2.1 mg/l respectively. 2. The contents of F were reasonable at Multonggol as 1.35 mg/l and Yongbayui as 0.57 mg/l respectively, but there is no detected at Sidong and detected below 0.1 mg/l at Gubongsan, Hansansa area. 3. According to the geological effect, the content of F was showed higher in granite than in tuff, and index of pH was higher in tuff than in andesite, and content of HCO$_3$ was higher in andesite than in granite. 4. The K and O values were used as index of healthy and delicious water. As a result, thirtyfive sites(74.5%) was decided as healthy and delicious water. 5. The contents of NO$_3$-N were detected over 5 mg/l at Sukchonsa, Gajanggol, Yudalsan, Muchang, Kisan.