• Economic and Environmental Geology
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• v.21 no.1
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• pp.45-56
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• 1988

Many hydrothermal skarn-type iron ore deposits inchiding Mulgeum, Yangseong, Maeri and Kimhae mines are distributed in the south-eastern Gyeongnam Province, Korea. The deposits are magnetite veins which occurred in propylitized andesitic rock near the contact with late Cretaceous Masanite. Symmetrical zoned skarns are commonly developed around the magnetite veins. The order of the skarn zones from the vein is garnet-quartz skarn, epidote skarn, and epidote-orthoclase skarn. The garnets include isotropic or anisotropic andradite($Ad_{100{\sim}70}$), and the epidotes are composed of pistacite($Ps_{21-31}$). Fe contents of the epidotes generally increase toward the magnetite veins. Epidotes and garnets often show compositional variations from grain to grain, that is, their Fe and Al contents vary inversely. This suggests that the variations depend mainly upon $fo_2$ during the skarnization. Oxygen and carbon isotope analyses of minerals from andesitic rock, micrographic granite, major skarn zones and post-mineralization zones were conducted to provide the information on the formation temperature, the origin and the evolution of the hydrothermal solution forming the iron ore deposits. Becoming more distant from the ore vein, temperatures of skarn zones represent the decreasing tendency, but most ${\delta}O^{18}$ and ${\delta}O^{18}_{H_2O}$ values of skarn minerals represent no variation trend, and also the values are relatively low. Judging from all the isotopic data from the ore deposits, the major source of hydrothemal solution altering the skarn zones and precipitating the ore bodies was magmatic water derived from the more deeply seated micrographic granite. This high temperature hydrothermal solution rising through the fissures of propylitized andesitic rock was mixed with some meteoric water, and the extensive isotopic exchange occurred with the propylitized andesitic rock. During this process, the temperature and ${\delta}O^{18}_{H_2O}$ value of hydrothermal solution were lowered gradually. At the stage of iron ore precipitation, because after all the alteration was already finished, the oxygen isotopic exchange with the wall rock was nearly not taken. The relatively high ${\delta}O^{18}$ and ${\delta}O^{18}_{H_2O}$, and relatively low ${\delta}C^{13}$ values of calcites of post mineralization stage, are the results of leaching of the high ${\delta}O^{18}$ chert xenolith in the andesitic rock and low ${\delta}C^{13}$ andesitic rock.

• Ocean and Polar Research
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• v.32 no.4
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• pp.337-350
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• 2010

This study conducted sedimentological and geophysical surveys for 3 years (2006-2008) in southern Gyeonggi Bay, Korea to elucidate temporal changes in subaqueous dune morphology on a sand ridge trending northeast to southwest that has been excavated by marine sand mining. The sand ridge (~20 m in height, ~2 km in width and 3~4 km in length) has a steep slope on the NW side and a gentle slope on the SE side, creating an asymmetric profile. Large (10~100 m in length) and very large (>100 m in length) dunes occurring on the SE side of the ridge show a northeastward asymmetrical shape, whereas dunes on the NW side destroyed by marine sand mining display a southwestward asymmetry. The comparison between Flemming (1988)'s correlation and the height-length correlation of this study indicates that tidal current and availability of sand sediment are major controlling factors to the development and maintenance of dunes. Depth and sedimentary characteristics (grain size) are not likely to be major controlling factors, but indirectly influence dune growth by hydrological and sedimentary processes. The length and the height of dunes decrease toward the southeastern trough away from the crest of the ridge. These features result from the decrease of tidal current and sediment availability. The length and the height of dunes on the southeast side decrease gradually over time. This is a result of the interaction between tidal current and the decrease in sediment availability due to sediment extraction by marine sand mining. Marine sand mining has destroyed the dunes directly, causing irregular shapes of shorter length and lower height. The coarse fraction of suspended sediments is transported and deposited very close to the sand pit. By contrast, relatively fine sediments are transported by the tidal current and deposited over a wide range by the settling-lag effect, resulting in a decrease of sediment grain size in the area where suspended sediments are deposited. In addition, marine sand mining, decreases the height of dunes. Therefore, morphological and sedimentological characteristics of dunes around the sand pits will be significantly changed by future sand mining activities.

• Journal of Plant Biotechnology
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• v.30 no.4
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• pp.365-368
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• 2003

Variations of agronomic traits were evaluated on the progenies of regenerated rice plants of different callus origin and subculture period. From eighty-eight percent to ninety percents of ovary culture-derived plants (OCP) and anther culture-derived plants (ACP) were not segregated within the lines in major agronomic characters. Compare to ACP and OCP lines, the seed culture derived lines (SCP) showed more segregation (17％) in major agronomic traits among the lines. The most frequent segregating traits were grain fertility (6.1％) in ACP, leaf color (4.2％) in OCP and grain fertility (4.9％) and leaf color (4.9％) in SCP lines. The SCP line showed more variation in culm length, panicle length and heading date than those of OCP and ACP lines. The variation of agronomic traits in SCP lines was tended to increase with prolonged subculture. Culm and panicle length were shorter than those of original cultivar in all three types of tissue culture-derived lines (OCP, ACP and SCP).

• Korean Journal of Food Science and Technology
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• v.12 no.4
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• pp.278-284
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• 1980

Lipids from rice bran (Indica type Milyang #23), both fresh and stored at $30^{\circ}C$ and 80% relative humidity for 5 weeks, were separated and analyzed for the determination and the storage effect on the bran lipid composition. Total lipids of fresh rice bran consisted of 89.9% neutral lipids, 8.0% glycolipids, 2.1% phospholipids and no significant changes of these fractions were noted during storage. Triglycerides(43.1%), diglycerides(13.8%) and hydrocarbon-esterified sterol(13.5%) among six fractions were considered as main components in neutral lipids. After storage triglycerides content significantly decreased as the free fatty acid increased in the neutral lipid fraction. Major components of the glycolipid fraction were acylsterolglycoside(43.1%) and sterolglycoside(30.3%). Phosphatidyl choline(39.8%), phosphatidyl serine(20.9%) and phosphatidyl ethanolamine(19.8%) were predominent in the phospholipid fraction. No significant changes of the composition were shown in fraction of the glycolipid or the phospholipid during the storage period. Major fatty acids of the total lipid fraction were oleic(44.3%), linoleic(32.5%) and palmitic acids(18.4%). The fatty acid compositions of the neutral lipid, the glycolipid and the phospholipid fractions were similar to the total lipid fraction. Small changes in fatty acid composition in each fraction were noted during the storage period. The acid value increased but iodine value decreased during the storage period. The values of peroxide and TBA increased gradually in the first three weeks, and then slowly decreased in the fourth and the fifth week of the storage.

• Journal of Wetlands Research
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• v.23 no.3
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• pp.213-223
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• 2021

To understand the sedimentary environment of Scirpus planiculmis habitat (Myeongji and Eulsuk tidal flats) in the Nakdong Estuary, this study analyzed the statistical parameters (sorting, skewness, and kurtosis) of grain size data and the major (Al, Fe, Mn, Mg, Ca, Na, K, Ti, and P), minor (Li, Sc, V, Cr, Co, Ni, Cu, Zn, Sr, Zr, Cs, Pb, Th, and U), and rare earth elements (REEs) in sediment cores. For Myeongji, the sediment structure of the upper part of the cores was poorly sorted, more finely skewed, and more leptokurtic due to construction of the West gate. By contrast, the Eulsuk cores all differed due to the contrasting floodgate operation patterns of the West and East gates. The linear discriminate function (LDF) results corresponded to the statistical parameters for grain size. At the Eulsuk tidal flat (sites ES05 and ES11), elemental distributions were representative of Al-, Fe- and Ca-associated profiles, in which the elements are largely controlled by the accumulation of their host minerals (such as Na- and K-aluminosilicate and ferromagnesium silicate) and heavy detrital minerals at the sites. Detrital minerals including the aluminosilicates are major factors in the elemental compositions at ES05, diluting the REE contents. However, clay minerals and Fe-oxyhydroxides, as well as REE-enriched heavy minerals, appeared to be controlling factors of the elemental composition at ES11. Therefore, the mineral fractionation process is important in determining the elemental composition during sedimentation, which reflects the depositional condition of riverine-saline water mixing at both sites.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.2
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• pp.165-173
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• 1985

The objectives of the study were to investigate the effects of foliage clipping on photosynthesis and grain filling for branch and non branch types under the polyethylene film mulch and non mulch conditions in mono cropping and second cropping after barley in sesame (Sesamum indicum L.), and to improve poor grain filling at later flowering time utilizing these data. One thousand grain weight was more decreased in branch type than in non branch type, in polyethylene film mulch condition than in non mulch condition, and in second cropping after barley than in mono cropping by clipping lower part foliage. Twentyfive percent clipping of lower part foliage showed a little increase than no clipping. Matured grain rate also showed same tendency between branch and non branch type and between mono cropping and second cropping after barley as well as 1,000 grain weight except for polyethylene film mulch. Matured grain rate of 25% foliage clipping at 30 days after flowering in non branch type presented a little increase but decreased in branch type. Clipping of higher part leaves were so serious decrease of matured grain rate that higher part leaves at late maturing time have a major role in photosynthesis. Matured grain rate of foliage clipping at 10 days after flowering was decreased in all treatments. Chlorophyll content of higher part leaves at 50% lower part foliage clipping presented 39% increase compared to same positioned leaves of non treatment, and 66% increase by 50% higher part foliage clipping in lower part leaves. Photosynthetic activity was 58% more increased in 50% lower part foliage clipping than no clipping, but seriously decreased in 50% higher part foliage clipping. Therfore, photosynthates of remained lower part leaves could not only support their own demands, but also any contribution to translocation of photosynthates from source to sink at late maturing time. Harvest index was 28% increased in 25% lower part foliage clipping and 13% decreased in 50% higher part foliage clipping compared to no clipping. Leaf area was 48% increased in 50% lower part foliage clipping compared to the same positioned leaves of no clipping, and only 5% increased in higher part foliage clipping. Productivity by foliage clipping compared to non treatment, was highly decreased in branch type than in non branch type, in second cropping after barley than in mono cropping. Little difference was detected between polyethylene film mulch and non mulch conditions. Twenty five percentage of lower part foliage clipping on mono cropping of non branch type appeared 5% and 8% yield increase in each of polyethylene film mulch and non mulch conditions compared to no clipping, and all decreased in other treatments. Mean loss of productivity by foliage clipping at 10 days after flowering was serious than clipping at 30 days after flowering. As the result, contribution to photosynthesis of source at 10 days after flowering are larger than that at 30 days after flowering in sesame. Fifty percent lower part foliage clipping at 10 days after flowering showed so the most serious yield decrease that lower part leaves at that time were considered as the main role leaves for photosynthesis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.4
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• pp.468-473
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• 2013

This study was conducted to make clustering analysis based on major physicochemical characteristics related to palatability of 394 Korean rice land-races. The items investigated were protein content, Mg content, K content, Mg/K ratio, Toyo-taste value, ADV (alkali digestion value) and amylose content. The range of the physicochemical characteristics such as amylose, protein, magnesium, potassium was from 12.4 to 28.9%, from 5.2 to 9.9%, from 12.7 to 37.7 mg and from 60.0 to 125.9 mg, respectively. In this experiment, the grain quality, properties significantly associated with the estimates of Toyo taste meter, were protein and amylose contents and hot viscosity. Also, at the expected taste as a cooking rice, using Toyo taste meter, a total 16 accessions were selected as good taste as "Ilpumbyeo". Also, IT173444, IT008530 and IT006554 were selected as remarkable sources for the cooking rice, in terms of gelatinated temperature and Toyo taste meter value.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.17-28
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• 2007

To understand the spring freezing injury symptoms during sensitive growth stage and yield loss of barley and wheat, field tests were done by using vinyl mulching and natural cold weather. The growth stage sensitive were booting, spikelet differentiation and flower organ development stages for both crops. However, barley and wheat differed in their growth responses, in that barley was less affected than wheat. For instance, barley recorded 28 percent dead ears, 10 percent dead plants and 18 percent ear degenerations while wheat recorded higher values of 59 percent, 44 percent and 44 percent, respectively. Although there were no recorded froze-resistant varieties in both barley and wheat, some showed tolerance as their yields were not affected by freezing stress. The 'Chalbori' cultivars of barley and 'Geurumil' and 'Chokwang' cultivars of wheat recorded steady yields. The yield components of barley and wheat that were greatly affected by freezing stress were the number of spike per square and the number of grain per spike. The major cause of yield loss in Suwon 259 and Kangbori was the number of spike per square but not the number of grain per spike. The study showed, however, that both the number of spike per square and the number of grain per spike were vulnerable to freezing and that which contribute much to yield loss of barley and wheat.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.470-476
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• 1986

In order to find out the optimum seeding date of Job's tears, this study was investigated ecological characters, yield components and yield of Jang Seong native variety at 6 seeding dates (March 20, March 30, April 10, April 20, April 30 and May 10). Emergence period and heading period were shortened as the seeding date was late, and the number of leaves on the main stem was increased as the seeding date was early. Maturing period was 63-66 days when we seeded in March 20, March 30, April 10 and April 20, and it was delayed 68-77 days when we seeded on April 3$^{\circ}$ and May 10. Culm length was longest in April 10 seeding (it was 186.6 cm), and it grew short in the early and the late seeding, but there was no significant difference among seeding dates. Stem diameter was thickest in April 10, and April 20 seeding, that is, thickened to 10.1 mm, and it was thin in the early and the late seeding. Productive tiller number per hill was increased most in April 10 and April 20 seeding, that is, increased to 6.2, and it was decreased in the early and the late seeding. 100 grain weight was heaviest in April 10 seeding; it was 10.7 g, and it was light in the early and the late seeding. Ripeness rate was highest in April 10 seeding (87.4%), and it was lowest in May 10 seeding (76.3%). Grain yield was highest in April 10 seeding (602.8kg per l0a); therefore this period is regarded as optimum seeding date. C. protein, C. fat, C. fiber and C. starch showed significant difference among seeding dates, and C. protein showed possitive correlation (r =0.9811 **) and C. fiber Negative collelation (r =-0.8937*) with seeding dates.

• Korean Journal of Materials Research
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• v.10 no.1
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• pp.55-61
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• 2000

The sintering characteristics of PVA-Al(III) complex added $UO_2$ pellet and AlOOH added $UO_2$pellet were compared. The major phase of PVA-Al(III) complex and AlOOH decomposed at $1000^{\circ}C$ in $H_2$atmosphere was $\theta-Al_2O_3$. Compared with the apparent density of pure $UO_2$, that of AlOOH added $UO_2$ powder was higher but that of PVA-Al(III) complex was lower. the densification of AlOOH added $UO_2$ pellet was initiated at about $800^{\circ}C$, the densification of PVA-Al(III) complex added $UO_2$ pellet was initiated at about $900^{\circ}C$ respectively. In a view of pore size distribution, the PVA-Al(III) complex added $UO_2$ pellet appeared as monomodal type, whereas the AlOOH added $UO_2$ pellet appeared as bimodal type. The grain size of AlOOH added $UO_2$ pellet was about $13\mu\textrm{m}$ but the grain size of PVA-Al(III) complex added $UO_2$ pellet was increased up to about $36\mu\textrm{m}$.