• Journal of Ecology and Environment
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• v.43 no.4
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• pp.438-453
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• 2019

Background: To investigate the trends of succession occurring at the Pinus thunbergii forests on the lowlands of Jeju Island, we quantified the species compositions and the importance values by vegetation layers of Braun-Blanquet method on the Pinus thunbergii forests. We used multivariate analysis technique to know the correlations between the vegetation group types and the location environmental factors; we used the location environment factors such as altitudes above sea level, tidal winds (distance from the coast), annual average temperatures, and forest gaps to know the vegetation distribution patterns. Results: According to the results on the lowland of Jeju Island, the understory vegetation of the lowland Pinus thunbergii forests was dominated by tall evergreen broad-leaved trees such as Machilus thunbergii, Neolitsea sericea, and Cinnamomum japonicum showing a vegetation group structure of the mid-succession, and the distribution patterns of vegetation were determined by the altitudes above sea level, the tidal winds on the distance from the coast, the annual average temperatures, and the forest gaps. We could discriminate the secondary succession characteristics of the Pinus thunbergii forests on the lowland and highland of Jeju Island of South Korea. Conclusions: In the lowland of Jeju Island, the secondary succession will progress to the form of Pinus thunbergii (early successional species)→Machilus thunbergii, Litsea japonica (mid-successional species)→Machilus thunbergii (late-successional species) sequence in the temperate areas with strong tidal winds. In the highland of Jeju Island, the succession will progress to the form of Pinus thunbergii (early successional species)→Neolitsea sericea, Eurya japonica (mid-successional species)→Castanopsis sieboldii (late-successional species) sequence in the areas where tidal winds are weak and temperatures are relatively low. However, local differences between lowland and highland of Jeju Island will be caused by the micro-environmental factors resulting from the topographic differences and the supply of tree seeds. From the characteristics of succession study, we could properly predict and manage the Pinus thunbergii forest ecosystem on lowland and highland of Jeju Island.

• Journal of the Korean Electrochemical Society
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• v.13 no.2
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• pp.89-95
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• 2010

The chalcopyrite $Cu(In_xGa_{(1-x)})Se_2$ (CIGS) is considered to be one of the effective light-absorbing materials for thin film photovoltaic solar cells. We describe the electrodeposition of CIGS thin films in ambient laboratory conditions, and suggest the electrochemical conditions to prepare stoichiometric CIGS thin films of Ga/(In + Ga) = 0.3. In acidic solutions containing $Cu^{2+}$, $In^{3+}$, $Ga^{3+}$ and $Se^{4+}$ ions, the CIGS films of different Cu/In/Ga/Se chemical compositions were electrodeposited onto Mo/Glass substrate. The structure, morphology and chemical composition of electrodeposited CIGS films were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Energy dispersive X-ray spectroscopy (EDS), respectively.

• Journal of the Korean Ceramic Society
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• v.44 no.11
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• pp.639-644
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• 2007

Spinel pigments, developing black color in high temperature glazes at oxidation or reduction atmosphere, without CoO because of its high price were synthesized by solid solution method. Ten mixed compositions consisted of NiO, MnO, $Fe_2O_3 and $Mn_2O_3$ were fired at $1250^{\circ}C$ for 1h. The resulting pigments were characterized by using XRD, FT-IR, SEM and UV-vis spectrometer. Structure of the pigments are spinel and particles' shape are spherical or cubic. Glazed tiles containing 5 wt% pigments were fired at $1260^{\circ}C$ and $1240^{\circ}C$ in reduction atmosphere. Color in glazes were analyzed by UV-vis spectrometer. Colors of NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.4875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0125 mole% and NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.3875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.1125 mole% in lime glaze showed black in oxidation, in reduction NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.4875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0125 mole% and NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.55{\cdot}Mn_2O_3$ 0.0125 mole% showed black. In case of lime-barium glaze, NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.3875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.1125 mole%, NiO 0.975 MnO $0.075{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0625 mole% and NiO 0.925 MnO $0.075{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0625 mole% showed black color in oxidation and NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.3875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.1125 mole%, NiO 0.925 MnO $0.075{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0625 mole% and NiO 0.725 MnO $0.275{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0625 mole% showed black one in reduction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1197-1203
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• 2001

This study was conducted to examine the effects of dietary xylooligosaccharide on UDP-glucuronyl transferase (UDP-GTase) activity and excretion of fecal sterols in rat fed high cholesterol diet. Sprague-Dawley male rats weighing 100$\pm$10 g were randomly divided into five groups, one with normal diet and four with high cholesterol diets containing 1% cholesterol (w/w). The high groups with cholesterol diet groups were classified into xylooligosaccharide free diet (C), 5% xylooligosaccharide diet (C5XO), 10% xylooligosaccharide diet (C10XO), and 15% xylooligosaccharide diet (C15XO) group according to the five groups of dietary xylooligosaccharide by weights. The experimental diets were fed ad libidum for 4 weeks. Fecal weights were increased 86% by xylooligosaccharide. Fecal total lipid contents including fecal neutral and acidic sterols in xylooligosaccharide groups were significantly higher than those of the normal and C groups, and especially that of C10XO group was the highest among all experimental groups. Activity of UDP-glucuronyl transferase (UDP-GTase) in liver in C group was 35% higher than that of normal group and the activities in C5XO, C10XO and C15XO groups were 15%, 41%, and 21% higher than in C group, respectively. Fecal bile acid excretions per day were increased 3.1, 3.6 and, 2.8 folds in C5XO, C10XO, and C15XO groups, respectively, compared with that of C group. Contents of neutral sterol, coprostanol, and coprostanone were higher in xylooligosaccharide groups than in C group. These results suggest that dietary xylooligosaccharide may act as potential substitute for a dietary fiber capable of improving a gastrointestinal function and lipid metabolism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1467-1474
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• 2006

Fish-frames, which are left after obtaining fillets or muscle during fish processing, consists of useful food components, such as muscle, collagen, calcium, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This study was carried out to prepare snack using conger eel frame (SF) for human consumption and also to elucidate food component characterization of the snack. The results of volatile basic nitrogen suggested that conger eel frame was a suitable material for preparing snack. Based on the results of sensory evaluation and costs, starch syrup was an optimal sweetener for preparing snack using conger eel frame. The starch syrup-treated SF appeared safe because the moisture content and peroxide value were below the safety limits described in the guideline of Korea Food and Drug Administration (KFDA). Starch syrup-treated SF was similar in the pattern of fatty acid composition to soybean oil, whereas EPA and DHA were detected in SF. The total content of amino acid in starch syrup-treated SF was 23.9% based on 100 g of raw material. The maj or amino acids were aspartic acid, glutamic acid, glycine and alanine. The total contents of calcium and phosphorus in starch syrup-treated SF were 4.9% and 2.8%, respectively. The Ca/P of starch syrup-treated SF was 1.9, which is a good ratio for absorption of calcium. The SF made with starch syrup was superior in EPA and DHA compositions, total amino acid, calcium and phosphorus contents to commercial snack using eel frame.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1091-1097
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• 2005

This study was carried out to develop jelly food using dried persimmon. Jelly products were prepared with the ratio of 5, 10, 15, 20 and $25\%$ of dried persimmon extract. Quality characteristics of its products were investigated. Proximate compositions of jelly were $6.74\~14.03\%$ of moisture, $6.83\~7.53\%$ of crude protein, $0.62\~1.16\%$ of crude lipid, $2.61\~13.21\%$ of crude ash, respectively. Water activity and brix $(\%)$ of jelly products ranged from 0.678 and $56.66\%\;to\; 0.748\;and\;76.59\%$. The pH and total acidity of jelly products ranged from 5.30 and $0.06\%$ to 5.38 and $0.09\%$. In the Hunter's color values, L, a and b vaules of jelly products were increased, respectively. Major free-sugar and organic acid of jelly products were maltose ($753\~1,297mg/100g$) and malic acid (263mg/100g in $25\%$ dried persimmon jelly). Major mineral of jelly products was K ($69.64\~154.37mg/100g$). In the texture property, addition of dried persimmon extract decreased gumminess and chewiness. In sensory score of dried persimmon jelly, color, flavor, texture and sweetness of $15\%$ dried persimmon jelly were high score, taste and overall acceptance of jelly products were high score, respectively. Judging from research results of the jelly products, recommended substitution level for addition of dried persimmon extract in jelly was $10\~15\%$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.285-290
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• 1984

Changes of free amino acids, nucleotides and their related compounds during the fermentation of yellow corvina entrails, Pseudosciaena manchurica, were analyzed. In fresh extract, alanine, glutamic acid, serine, lysine and leucine were dominant amino acids, and content of arginine, aspartic acid, cystine and tyrosine were low. The free amino acids analyzed in this experiment were not changed in composition but changed in amounts during the fermentation of yellow corvina entrails. Alanine, glutamic acid, lysine and leucine were abundant in both fresh sample and fermented products. Content of ATP, ADP, AMP and IMP decreased while hypoxanthine increased during the fermentation of yellow corbina entrails. The total free amino acid nitrogen at 30 day fermentation was 71% of its extract nitrogen. It is believed that such amino acids as glutamic acid, alanine, lysine, valine, leucine, nucleotides and their related compounds as hypoxanthine play an important role as taste compounds in fermented yellow corvina entrails.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.3
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• pp.27-34
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• 1987

The present paper was attempted to obtain the basic date concerning a reasonable preparing method and optimum fermentation conditions of Kochujang (Red pepper paste). To establish the standard quality of Kochujang, the chemical compositions and the volatile components of Kochujang was discussed. The native Kochujang collected from 80 households contained 40.51% of moisture, 6.00% of salts, 3.25 % of crude fat, 10.30 % of crude ash, pH 4.79, 9.28ml of tillable acidity. 19.60% of reducing sugar, 179.51 mg/100g of amino nitrogen and 4.43% of total nitrogen. The volatiles of Kochujang were extracted by a steam-distillation under the reduced pressure and determined by gas chromatography-mass spectrometry (GC-MS). Total volatile components identified in the native Kochujang were 46 components, i. e., 30 components in neutral fraction, 8 components in phenolic fraction and 8 components in acidic fraction, respectively. But no components were detected basic fraction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.259-262
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• 1984

In order to examine the effect of oil extraction methods on the charateristics of sesame oil, the fractionation pattern and fatty acid compositions of the each fraction of the oil were compared in the oil extracted by the three different extraction methods, that is, pressure extraction of roasted seed (RTP), acetone extraction of roasted seed (RTE) and acetone extraction of raw seed (RWE). The amount of triglyceride in RWE oil was slightly higher as 77.2% of the total lipid than that in RTP and RTE oil of 73.4%. The content of oleic and linoleic acid in glycolipld and fatty acid fractions, linoleic acid in triglyceride, and palmitic and stearic acid in phospholipid fractions from RTP and RTE oil were higher than those from RWE oil, but the oleic acid in triglyceride. Palmitic and stearic acid in free fatty acid, and oleic and linoleic acid in phospholipid from RTP and RTE oil were lower than those from RWE oil. The ratio of $C_{18}$ to $C_{16}$ fatty acids and unsaturated to saturated fatty acids in glycolipid and phospholipid fractions from RTP and RTE oil were higher than those from RWE oil, but the ratios in triglyceride and free fatty acid fractions from RTP and RTE oil were lower than those from RWE oil.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.2
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• pp.128-135
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• 1986

Wheat germ protein was extracted and isolated by a Modified Osborne fractionation method and some properties were investigated. The results are summarized as follows; 1. Approximate compositions of wheat germ were moisture 10.5%, crude protein 22.8%, crude fat 2.4%, crude ash 3.2%, crude fiber 1.5%, respectively. 2. Nitrogen solubilities on various solvents were the lowest as 45.58% by Osborne method and the highest as 79.49% after sequencial extraction of the $H_2O$, 0.5M-NaCl, 70%-ethanol, 0.1N-NaOH. 3. Isolated proteins yielded albumin, globulin, globulin, gliadin and glutelin in the proportion of 20.22: 17.49: 42.58: 19.71, respectively. 4. Spectrophometric chromatograms of isolated protein by Regel-filtration were two peaks in albumin (I ; 8.2%, II ; 91.8%), one peak in globulin (92.8%), respectively. 5. Disc-PAGE patterns were showed about 14 bands in 0.5M-Cl soluble protein, 3bands in crude albumin, 1band in main albumin, 2bands in crude globulin, one band in main globulin under pH 8.3 buffer system (Ornstein and Davis method).