• Geomechanics and Engineering
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• v.12 no.5
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• pp.803-813
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• 2017

This study discussed the possible optimization of enzyme-mediated calcite precipitation (EMCP) as a soil-improvement technique. Magnesium chloride was added to the injection solution to delay the reaction rate and to improve the homogenous distribution of precipitated minerals within soil sample. Soil specimens were prepared in 1-m PVC cylinders and treated with the obtained solutions composed of urease, urea, calcium, and magnesium chloride, and the mineral distribution within the sand specimens was examined. The effects of the precipitated minerals on the mechanical and hydraulic properties were evaluated by unconfined compressive strength (UCS) and permeability tests, respectively. The addition of magnesium was found to be effective in delaying the reaction rate by more than one hour. The uniform distribution of the precipitated minerals within a 1-m sand column was obtained when 0.1 mol/L and 0.4 mol/L of magnesium and calcium, respectively, were injected. The strength increased gradually as the mineral content was further increased. The permeability test results showed that the hydraulic conductivity was approximately constant in the presence of a 6% mineral mass. Thus, it was revealed that it is possible to control the strength of treated sand by adjusting the amount of precipitated minerals.

• Economic and Environmental Geology
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• v.31 no.1
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• pp.69-84
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• 1998

A geochemical study was carried out to define how marine shore sediments are related to their terrestrial source rocks in the region of Taean and Byunsan Peninsula, western Korea. The lithology of the coastal part of the study area is composed of Pre-Cambrian granite gneiss, schist, Jurassic terrestrial sedimentary rocks, and Cretaceous plutonic intrusives. Shore sediments are transported from three drainage tributaries. The sediments consist of quatrz with clay minerals, such as illite, kaolinite, smectite, chlorite. Heavy minerals include hematite, ilmenite, rare amount of zircon and apatite. Compared to those in coastal rocks, amount of heavy minerals in the sediments is considerably low. The low content of heavy minerals is thought to be attributed to the heavy mineral detainment in the river beds and influences of tidal currents which cause heavy minerals to accumulate in specific spots. Chemical composition of the major and trace elements, trace elements, and REE chondrite normalized pattern suggest that shore sediments transported from the corresponding drainage tributary show close mineralogical and geochemical relationships with the source rocks distributed in the Taean and Byunsan Peninsula.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.386-387
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• 2006

This study is about the recycling technology of scrap a PCB(printed circuit board) produced in home appliances or automobile industry. And we develop the recycling technology of cooper (Cu)which is contained to leaching solution. In stead of electrolytic collecting in existing sulphuric atmosphere, we apply process using the ammonia solution which is used in economizing energy. So m the process of electrolyzing scrap a PCB through the leaching and separation, we examine the effect of the nickel contained to the solution and the cooper degree of purity which is changed according to current density.

• Economic and Environmental Geology
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• v.7 no.2
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• pp.63-78
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• 1974

Daehwa tungsten-molybdenum deposits is fissure filled quartz veins occurring in Precambrian granite gneiss adjacent to the contact with Mesozoic biotite granite mass. Essential ore minerals are molybdenum and wolframite accompaning scheelite, cassiterite, chalcopyrite, pyrrhotite, pyrite and bismuthinites. Gangue minerals are quartz and little muscovte, fluorite, beryl and Carbonate minerals. Fluid inclusions in quartz, fluorite, beryl, scheelite and calcite have filling temperature ranges of $170-353^{\circ}C$. According to the studies of mineral paragenesis and filling temperature of fluid inclusion indicate that main tungsten and molybdnum mineralization have taken place with the minerals whose filling temperature ranges 205 to $353^{\circ}C$. Liquid $CO_2$ bearing fluid inclusions are characteristic in the quartz and early fluorite of tungsten and tungsten bearing molybdenum veins but hardly recognized from molybdemun veins. Estimated $CO_2$ concentration according to diagram proposed by the Takenouchi ranges from 10 to 20wt%. These facts suggest that tungsten mineralization may be related to the $CO_2$ content of the hydrothermal solution during the mineralizing period.

• Journal of the Korean Ceramic Society
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• v.44 no.9
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• pp.477-482
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• 2007

The effect of the mixing ratio of compounds in a slag-OPC-Gypsum system on the physical properties of Slag cement is investigated in this study. $Na_2SO_4$ was used as an alkali activator. Blast furnace slag cement was prepared from a mixture of blast furnace slag, ordinary Portland cement and anhydride gypsum. The fluidity and the compressive strength according to the ratio of each mixture were analyzed in statistical analyses in order to discover the parameters influencing the fluidity and compressive strength. The results showed that the hydration of blast furnace slag took place with the addition of $Na_2SO_4$ and that column-crystalline ettringite was created as the main hydration product of the blast furnace slag. In addition, it was found that the compressive strength of blast furnace slag cement tends to increase when the ordinary Portland cement content is higher up to three days. However, it is known that the compressive strength tends to increase as the blast furnace slag content becomes higher with increases in the level of OPC after 28 days. As a result of this analysis, it is believed that the ordinary Portland cement content influences the initial compressive strength of blast furnace slag cement, and that in later days this is highly influenced by the slag content.

• Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.409-419
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• 2014

The proximate composition and various specific components of Antarctic krill Euphausia superba, in the catch season between March and August were investigated. Frozen krill were freeze-dried and milled. The proximate composition comprised water, proteins, fats, ash, fatty acids, and amino acids, while the specific components were vitamins, minerals, nucleotides, betaine, and astaxanthin. The moisture content of the krill ranged from 77 to 80%, with the highest value in June, and the ash content was between 12 and 13%. The protein content was lowest in May, and the fat content was 18-19%, with the highest value in March. The amino acid content varied according to the season: taurine and glycine were highest in August; ${\beta}$-alanine was higher in April and May; and arginine, ornithine, and lysine were highest in March. The unsaturated fat content was ~50% and omega-3 fatty acids were highest in June. Oil-soluble vitamins A and E were highest in March, and the water-soluble vitamin content was less than that of oil-soluble vitamins. The mineral content was highest in June, and the most abundant mineral was sodium at 235.60 mg/100 g krill. The content of other minerals was lowest (2.94 mg/100 g) in April, except for lead. The nucleotide content was highest in July, while the betaine content was highest in April and lowest in June. The astaxanthin content was highest in May and ranged from 6 to 10 ppm in other months.

• Current Research on Agriculture and Life Sciences
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• v.32 no.2
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• pp.75-78
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• 2014

Burdock (Arctium sp.) is known as a nutraceutical vegetable, especially in Japanese and Korean cuisine. While burdock plants are generally harvested for their tap roots, different parts of the plant are consumed as food or used as traditional medicines. This study investigated the physicochemical properties of the leaves, stems, roots, and peeled roots of the burdock plant based on their pH, soluble solid content, titratable acidity, color values, and mineral content. The pH differed significantly among the different plant parts, with the highest value in the leaves and the lowest in the stems. However, for the soluble solid content, the leaves had the lowest, while the peeled roots had the highest. The titratable acidity of the stems was significantly lower than that of the leaves, roots, and peeled roots. As regards the color values, the lightness value was highest for the stems, while the roots showed the highest redness value, followed by the peeled roots, and the leaves had the highest yellowness value. The leaves and stems contained almost three times more potassium than the roots and peeled roots. Thus, the higher content of different minerals in the leaves and stems of the burdock plant shows that these plant parts could be used as potential sources of dietary minerals.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.2
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• pp.221-227
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• 2004

Nutrient utilization and plasma level of minerals were studied in lactating crossbred cows fed diet supplemented from different source of minerals. Twelve crossbred cows of first to third lactation during their mid stage of lactation were distributed equally under two groups and were fed concentrate mixture, green fodder (para grass) and finger millet straw as per requirement. Cows in group I were fed concentrate mixture supplemented with 1% mineral mixture whereas cows in group II were not supplemented with mineral mixture in the concentrate mixture but were offered additional quantity of green fodder (1 kg DM/cow/day) to compensate for the requirement of minerals. Balance study conducted towards the end of 120 days of feeding experiment indicated that the total dry matter intake in both the groups did not differ significantly. The cows in group II offered additional quantity of green fodder consumed significantly (p<0.05) more of green fodder (5.11 vs. 4.51 kg /animal/day) and the cows in group I consumed significantly (p<0.01) more of finger millet straw (1.71 vs. 0.92 kg/animal/day). The digestibility of major nutrients did not differ between the groups except for ether extract which was significantly (p<0.05) lower in cows fed additional green fodder. The total daily intake of P, Cu, Fe and Co did not differ significantly in both the groups whereas significantly higher intakes of Ca, Mg, Zn and Mn were observed in cows supplemented with inorganic source of minerals. However, supplementation through both the sources could meet the mineral requirement in group I and group II. The gut absorption (%) of all the minerals was comparable between the groups except for Mg which was significantly (p<0.05) higher in cows supplemented mineral mixture. The net retention of all the minerals was significantly more in the group supplemented with inorganic source of minerals. Except for P, Mg and Co the retention as percentage of total intake was comparable for all minerals in both the groups. Irrespective of source of mineral supplementation the average monthly blood plasma mineral levels (Ca, P, Mg, Cu, Zn, Fe) were within the normal range and comparable between the groups. Lower level of Cu observed at the start of the experimental feeding in both the groups increased with the advancement of supplemental feeding. The plasma Zn and Fe content in cows of both the groups did not vary. The blood plasma level of some minerals (Ca, P, Mg and Cu) was significantly higher towards the end of experimental feeding as compared to the initial values due to the reduction in milk yield with advancement of lactation or due to supplemental effect of minerals. It could be concluded that supplementation of minerals through inorganic source is better utilized in terms of retention as compared to green fodder (para grass), which is a moderate source of most nutrients.

• Journal of Mushroom
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• v.15 no.4
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• pp.216-222
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• 2017

This study was conducted to investigate the proximate composition, free sugars, amino acids, and minerals in five Lentinula edodes cultivars collected in Korea. No significant differences in the content of crude fat and crude fiber were found between the samples; however, there was significant variation in the contents of nitrogen free extract, ash, and crude protein. Three kinds of free sugars (fucose, arabinose, and glucose) were identified by HPLC, with the glucose content ranging from 5.94% to 12.08%. Sixteen kinds of free amino acids were identified: the highest content of amino acids was found in 'Sanlim5ho' (13,768.33 mg%), while the highest content of free amino acids was found in 'Sanlim4ho' (6,790.57 mg%). The minerals detected in the L. edodes cultivars were potassium, calcium, magnesium, and sodium, the contents of which ranged from 567.16-2,356.09 mg%, 3.85-7.42 mg%, 9.79-20.88 mg%, and 19.60-22.62 mg%, respectively.

• Journal of the Mineralogical Society of Korea
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• v.15 no.1
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• pp.11-21
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• 2002

A mineralogical study was made in order to identify the relationship between uranium content in groundwater and rock chemistry using core rocks recovered from the drilling holes for wells in the Daebo Granite areas. Uraniferous minerals are of primary origin and occur as inclusions in accessory minerals such as zircon, monazite, and xenotime. Since the uraniferous minerals are very small to be 1 ~ 2 $\mu$m in size, it is difficult to distinguish their mineralogical species precisely. The frequent presence of dissolution cavities or dissolved textures in the accessory minerals suggests that uraniferous minerals dissolved partially and contributed to the groundwater chemistry. Because there is no clear relationship between host rocks and groundwater for uranium concentration, mineralogical characteristics of uraniferous minerals, together with aqueous geochemical conditions favorable for uranium dissolution, could play important roles in groundwaster chemistry.