• Korean Journal of Soil Science and Fertilizer
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• v.35 no.5
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• pp.253-263
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• 2002

To test for the effect of applied fertilizer and nutrients on uptake and transport for paddy rice, two paddy field trials were conducted with Dongjinbyeo in degenerated salt paddy field of Jeonbuk series from 1999 to 2000. After experiment, soil acidity, content of organic matter phosphate, silicate, potassium, calcium, and total nitrogen was increased by application of fresh cattle manure(FCM). Content of Nitrogen in soil layer leached inorganic nitrogen $NO_3$ was higher that that of $NH_4$ and was high in treatment of FCM. Content of $PO_4$ was higher in FCM than other treatments. But content of potassium was in high control. During the growth of rice plant, the amount of water consumption was 477mm. The amount of supplied nitrogen was high in treatment of no nitrogen(NN), 20% reduced application of LCU(LCU-20%), and no fertilizer. In case of phosphate, the supplied amount was more than the consumed amount with the exception of treatment "no phosphate(NP) and no fertilizer(NF)". In case of potassium, the consumed amount was more than the supplied amount in all treatments. The amount of applied nitrogen in the nutrient infiltrated water was high in treatment soil test(ST), C+FCM+Si(Silicate) and the ratio of recovered nitrogen was high in 20% reduced application of LCU. The amount of applied phosphate in the nutrient infiltrated water was high in FCM and that of applied potassium was high in 20% reduced application of LCU. Nitrogen use efficiency of paddy rice was high in 20% reduced application of LCU and use efficiency of phosphate and potassium was high in C+Si(Silicate). Grain yield of rice was high in order of 20% reduced application of LCU>C+Si=C+FCM+Si>C+FCM.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.179-186
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• 2009

Relation between soil salinity and forage yield of five upland crops such as sudan grass, sesbania, barnyard grass, corn and soybean was studied in the three reclaimed lands of Korea during two years from 2007 to 2008. Although plant number emerged was obtained satisfactory by desalting treatment, further growth of crops was sharply affected by re-salting process according to soil drying. Soil salinity varied place by place and changed constantly, crop growth was differently responded to soil salinity according to the specific conditions of the reclaimed lands. In the Iweon reclaimed land with higher soil water conductivity and sandy soil texture, crop growth and yield sharply decrease with increase of soil salinity. Relation between soil salinity and crop growth and yield was well expressed as logarithmic function. Surface soil EC to reach at 50% of growth reduction to the tallest height of crops was $5dS\;m^{-1}$ for soybean, $6dS\;m^{-1}$ for corn and $7dS\;m^{-1}$ for sudan grass, sesbania, and barnyard grass by logarithmic function. In the Hwaong and Yeongsangang reclaimed lands with low soil conductivity and finer soil texture, plant growth response to salt stress was statistically vague by mixing of harmful influence from flooding and wet injury. However, it is observed that crop growth and yield on the place of lower salinity was better than crop growth on the place of higher salinity. It is accordingly concluded that flooding control during summer rainy season is vary important as well as desalting process for good growth of soiling and forage crops in the newly reclaimed land from tidal flat.

• Food Science and Preservation
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• v.19 no.1
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• pp.116-122
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• 2012

The antioxidant activities of $makgeolli$ and other alcoholic beverages were compared. Based on the same volume (70 ${\mu}L$ eq.) of the alcoholic beverages, the 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid ammonium salt) (ABTS+) radical-scavenging activities were as follows: whisky > $makgeolli$ crude extract (MCE) > rice wine (RW) > clarified $makgeolli$ (CM) > soju. Based on the same alcohol concentration (6%) of the alcoholic beverages, however, $makgeolli$ showed the highest activity. In addition, based on the same volume (70 ${\mu}L$ eq.), the inhibition effects against the formation of cholesteryl ester hydroperoxide (CE-OOH) were as follows: soju > whisky > RW > MCE > CM. Based on the same alcohol concentration (6%), however, the inhibition effects against the formation of CE-OOH were as follows: RW > MCE > soju > whisky > CM. Therefore, it was suggested that $makgeolli$ may contain radical-scavenging- and metal-ion-chelate-type antioxidants and may increase the antioxidant activity in the blood.

• Clinical and Experimental Reproductive Medicine
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• v.18 no.2
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• pp.153-162
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• 1991

The present study was undertaken to clarify the role of calcium ion as a factor for the maturation of follicle-enclosed mouse oocytes. Follicles were isolated with two sharp needles under a stereomicroscope from mouse(ICR) ovaries which were treated PMSG 5 IU 45 hours previously. Isolated follicles were cultured for 14-16 hours in an organ culture system at $37^{\circ}C$, 5% $CO_2$ in air and in a 100% humidified incubator by treatment of hCG, EDTA and $^{45}Ca^{++}$. Culture medium was Modified Hank's Balanced Salt Sol. (MHBS) and addition of hCG (human chorionic gonadotropin) was made into two doses level 0.4 IU and 0.8IU from the stock sol. and also $^{45}Ca^{++}$ was treated in the culture medium. To explain the role of calcium, calcium chelating agent EDTA was treated to the culture of the mouse follicle-enclosed oocytes. Two observations were made in the present study; nucleus phase and $^{45}Ca^{++}$ uptake into the oocyte. HCG induced oocyte maturation in the follicle about two folds as much as the control group, whereas there is no difference in oocyte maturation between 0.4 IU and 0.8 IU of hCG. Optimum level of hCG seems to be 0.4 IU/ml in the mouse follicle culture. HCG stimulated $^{45}Ca^{++}$ uptake into the oocyte of the follicles by two folds. $^{45}Ca^{++}$ uptake in the control group is about 2.5 folds in comparison of the EDTA(1.71mM) treated group. However, calcium uptake in the EDTA treated groups tends to increase depending on the decrease of EDTA concentration. These observations suggest that firstly, hCG stimulates maturation of the oocyte of the follicle, secondly, $Ca^{++}$ influx is induced by hCG and thirdly, $Ca^{++}$ influx by the treatment of EDTA decreases as a dosage-dependent process. This $Ca^{++}$ uptake may take place by the changes of permeability which was induced by hCG treatment. That is, $Ca^{++}$ influx may trigger the resumption of oocyte maturation. It is further necessary in the future study how this $Ca^{++}$ uptake is induced by hCG and increases permeability of the follicle and oocyte.

• Journal of the Korean GEO-environmental Society
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• v.19 no.10
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• pp.21-26
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• 2018

Soil-water characteristic curve, which is called soil retention curve, is required to explore water flows in unsaturated soils, relative permeability of water in multi-phase fluids flow, and change to stiffness and volume of soils. Thus, the understanding of soil-water characteristic curves of soils help us explore the behavior of soils inclduing fluids. Biopolymers are environmental-friendly materials, which can be completely degraded by microbes and have been believed not to affect the nature. Thus, various biopolymers such as deacetylated power, polyethylene oxide, xanthan gum, alginic acid sodium salt, and polyacrylic acid have been studies for the application to soil remediation, soil improvement, and enhanced oil recovery. PAA (polyacrylic acid) is one of biopolymers, which have shown a great effect in enhanced oil recovery as well as soil remediation because of the improvement of water-flood performance by mobility control. The study on soil-water characteristic curves of sandy soils containing PAA (polyacrylic acid) has been conducted through experimentations and theoretical models. The results show that both capillary entry pressure and residual water saturation dramatically increase according to the increased concentration of PAA (polyacrylic acid). Also, soil-water characteristic curves by theoretical models are quite well consistent with the results by experimental studies. Thus, soil-water characteristic curves of sandy soils containing biopolymers such as PAA (polyacrylic acid) can be estimated using fitting parameters for the theoretical model.

• Journal of Aquaculture
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• v.11 no.1
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• pp.99-103
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• 1998

Artemia often observed as a co-existing organism in the mass culture tank of marine rotifer. The rotifer and Atremia are commonly used as food organisms in the marine fish larvae rearing. In this study, interspecific relation between the rotifer Brachionus rotundiformis (formely called S-type) and anostracan Artemia of the two developmental stages (0 and 19 day old after hatching) were investigated in the larboratory. The population growth of B. rotundiformis and one of the stage (nauplius or adult) of Artemia in mixed culture was compared with that of each single species culture. Culture period was 16 days. Every two days, the number of organisms in each species was counted and transferred to a fresh medium containing $7{\times}10^5$cells/ml of food Nannochloropsis oculata. Culture volume, temperature, salinity and photoperiod were set at 40ml, $25^{\circ}C.$, 22ppt and 24h all dark except to observation time, respectively. The rotifer population growth was greatly decreased by co-existence with Artemia. The coexisting Artemia suppressed the rotifer population growth due to it's high filtering speed for food (N. oculata). This study suggested that contamination by Artemia must be prevented for the stable rotifer production in the rotifer mass culture tank.

• Korean Journal of Plant Tissue Culture
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• v.27 no.1
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• pp.31-37
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• 2000

Proton extrusion by hairy roots of Panax ginseng C.A. Meyer was enhanced by iron-deficiency or single salt solutions of nitrate or ammonium salts. The enhancement effect of iron-deficiency was confined to the apical zones, whereas that of nitrate and ammonium was confined to the basal root zones. tinder iron-deficiency medium, the proton extrusion of ginseng hairy roots was higher at two times than that grown in the medium of iron-sufficiency. According to pH in the medium, uptake of inorganic elements showed various patterns for the kind of inorganic elements. $Ca^{2＋}$, $Mg^{2＋}$ and Fe$^{2＋}$ were highest uptake at the pH 4.8 and Mn$^{2＋}$, Zn$^{2＋}$ and Cu$^{2＋}$ were highest uptake at the pH 3.8. Free sugars and ginsenosides were analyzed by HPLC. Five kinds of free sugars were indentified in ginseng hairy roots. Glucose, fructose and sucrose were a major sugar in ginseng hairy roots and contents of free sugars were highest at pH 6.8 and pH 4.8, respectively. The contents of ginsenosides and phenolic compounds were highest at pH 5.8. This physiological responses in ginseng hairy root indicated that it may well be a good model system for the study of mechanism of mobilization and uptake of inorganic elements related with the red-colored phenomenon in ginseng roots.

• Korean journal of food and cookery science
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• v.27 no.3
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• pp.29-37
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• 2011

Protease activity of fig (Ficus carica L.), cultivated in Korea was estimated. In particular, the proteolytic effect on myofibrilar protein was studied. A crude protease extract of fig was prepared in two ways; fig was homogenized in buffer followed by centrifugation, and the supernatant was precipitated by saturated ammonium sulfate followed by dialysis. The former method resulted in 41.15 mM/g fig protease activity, whereas the latter method resulted in 17.65 mM/g fig protease activity. The crude fig protease extract showed high specificity for casein as a substrate followed by egg white, bovine serum albumin, myofibrilar protein, collagen, and elastin. The extract had stable proteolytic activity in a pH range of 6.5~9.0 (optimal at pH 7-8) but lost activity, at pH 2-3. Proteolytic activity for myofibrilar protein was sensitive to pH. The proteolytic activity of the fig extract was steady up to $60^{\circ}C$ but declined at higher temperature. It also began to lose stability in salt concentrations >0.7 M NaCl. Fig has been used as a meat tenderizer for cooking, and these results support the tenderizing effectiveness of fig, particularly for Korean style meat marinating.

• Food Science of Animal Resources
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• v.31 no.4
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• pp.588-595
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• 2011

In this study, the effects of red ginseng extracts (RGE), which has been used as an antioxidant and antimicrobial agent, on pork sausage were evaluated. The treatments were as follows; addition of 0.01% sodium ascorbate (V), 0.5% RGE (T1), 1.0% RGE (T2) and 1.5% RGE (T3) to the basal formula (C). T3 had a significantly higher pH, cooking loss and yellowness ($CIEb^*$) and lower lightness (CIE $L^*$) and redness (CIE $a^*$) than the other samples. The hardness and surface hardness values of 1.5% RGE treated sample were significantly lower (p<0.01) than those of C. However, the cohesiveness values of the RGE samples were higher than the others (p<0.05). In the sensory evaluation, no significant differences in color, taste, texture, juiciness and acceptability were observed among the tested samples, while, the aroma scores of T2 and T3 were higher than those of the C and V samples (p<0.05). The TBARS values of RGE treated groups were higher (p<0.05) than the C sample after 1, 2 and 3 weeks of storage; however, this value did not increase with storage time (p>0.05). When the RGE concentration was high, the reduction in total plate counts and VBN value at week 3 and 4 of storage (p<0.01) decreased. In conclusion, red ginseng extracts seemed to have a positive impact on lipid oxidation, aroma and the microbial characteristics of pork sausage.

• Korean Journal of Food Science and Technology
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• v.24 no.1
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• pp.42-48
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• 1992

The rate and extent of coagulation of milk using fast acidification with 0.1 N HCl were monitored by changes in viscosity and turbidity at various temperatures and pH. Also the gelation rate of milk using slow acidification with D-glucono-${\delta}$-lactone was measured in a small strain rheological scanner. Coagulation of milk casein occurred in a specific pH range and was accompanied by an abrupt increase in viscosity at pH 5.0. Acid coagulation rate was enhanced by increasing temperature from $20^{\circ}C{\sim}50^{\circ}C$, and the maximum rate was shown around pH 5.0. The addition of salt ($CaCl_{2}$) reduced the maximum coagulation rate at all temperature ranges and shifted the pH ranges for maximum coagulation rate and the onset pH of coagulation. The onset of gelation and the rate of network formation during slow acidification were facilitated by Cl ion, but suppressed by SCN-ion, as indicated by the rate of rigidity development. The susceptibility to syneresis was greater in the gel made at lower temperature and around pH 4.6, while preheated milk at $90^{\circ}C$ for 5 min prior to acidification showed the same syneresis profile at all heating temperatures ($60{\sim}90^{\circ}C$).