• Korean Journal of Veterinary Research
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• v.27 no.2
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• pp.331-334
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• 1987

The effects of ethylene glycol as a cryoprotective agent on the survival of frozen-thawed mouse embryos were examined. The effects of the stage of development of ethylene glycol were also examined. Eight-cell embryos, morulae, early blastocysts and mid-blastocysts were recovered from superovulated immature ddY mice. Ethylene glycol was added to the embryos in 5 equal increments 5 minutes apart, giving a final concentration of 1.5M. The embryos were cooled to ${-6^{\circ}C}$ at ${1^{\circ}C/min}$ and seeding was induced at ${-6^{\circ}C}$. After being held for a further 5minutes at the seeding temperature, the samples were cooled to ${-35^{\circ}C}$ at ${0.3^{\circ}C/min}$ and then transferred to liquid nitrogen. Rapid thawing was done by placing the straws in ${37^{\circ}C}$ water. The thawed embryos were diluted in PBS of same time and manners as adding procedures. Survival of 8-cell embryos and morulae were assessed as a normal development of the embryos to the blastocyst stage and expanding blastocyst after 54 hours and 48 hours of in vitro culture, respectively. While those of the early and mid-blastocysts were assessed to the expanding blastocyst stage after 24 hours of in vitro culture. The survival rates of 8-cell embryos, morulae, early blastocysts and mid-blastocysts were 73.8%, 74.3%, 87.8% and 77.4%, respectively. Significant difference on the survival rate among the four stages of development was not observed.

• Journal of the Korean Ceramic Society
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• v.52 no.4
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• pp.273-278
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• 2015

${\alpha}-Al_2O_3$ was synthesized by solvothermal synthesis using ${\alpha}-Al_2O_3$ seed, precursor of fine boehmite (Al(OOH)) or gibbsite ($Al(OH)_3$), and 1, 4-butanediol solvent. The seed content and precursor type were selected as variables in order to synthesize ${\alpha}-Al_2O_3$. The formation time of ${\alpha}-Al_2O_3$ was reduced and the size of the particles was decreased with addition of the seed. When the seed content was increased, the size of the synthesized ${\alpha}-Al_2O_3$ was reduced. Morphologies of the as-synthesized ${\alpha}-Al_2O_3$ with ${\alpha}-Al_2O_3$ seed were polyhedron-shaped, while the shape was plate-like or polyhedral without the seed, depending on the additives or the average particle size of the boehmite precursor. The aggregation of as-synthesized ${\alpha}-Al_2O_3$ from boehmite was smaller than that from gibbsite. As-synthesized ${\alpha}-Al_2O_3$, with 140 nm size, was obtained by using the seed and boehmite precursor.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.1
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• pp.86-92
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• 1992

Green buckwheat seedlings have been used as a pollution free vegetable and medicinal crop for a long time. Some of the reasons are the rapid growth rate, the high protein and rutincontent, and a more favorable ratio of leaf to stem than mature plants. Off-crop season cultivation techniques were developed for growing the young and green buckwheat vegetable of higher quality and yield, and for its increased value-added income. The effects of planting season, seeding rate, seed bed soil fertility and type, and seedling growth period on yield and rutin content were determined for vegetable and medicinal use. The young vegetable yields. in the off season culture ranged from 2.62t/ha to 22.7t /ha. The highest vegetable yield was 22.7t /ha for 25 days old seedlings grown in the polyethylene film tunnel from March 30 to April 25, 1991 where seedling rate was 360kg /ha. Buckwheat vegetable quality and income were dependent upon planting season, seeding rate, growing duration and temperature, and facilities of raising seedlings. Protein content of buck-wheat seedlings was from 21.5% to 17.2%. Rutin content of the vegetable was 53.9～31.7mg /100g for the whole plant in average. The protein and rutin content was significantly varied due to the different environmental conditions including fertility and type of seed bed soil, growing duration, temperature of the green house, and polyethylene film house and tunnel.

• The Korean Journal of Ecology
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• v.15 no.2
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• pp.103-115
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• 1992

This dissertation, which has been prepared in the region of cheju(33o31'N, 126o32'E) from may,1987 to appril, 1989, is to elucidate the dominant characteristics of early stages in secondary succession, by examining the life history of erigeron annuus for the seeding depth of a seed was dependent upon the degree of shading. That is, on the area of ocm,the more tense the shading was, the more germination percentage was increased, while, in the case of 1.5cm, it was somewhat increased, when shading bwcame ess and less tense. The rosette of e. annuus, through its relative light intensity was decreased by shading, up to 5% of natural light, showed some strong shade tolerance, which had no difficulty in matter production. The species diversity of mixed-species community was the highest in the middle of April, the lowest in the last of may. The dominance index was the highest in the late may, the lowest in the middle of April. Toward the end of may, the occupation rate of dominance species was the highest. There was a neutral relationship between intraspecific and interspecific, owing to the differentiation of its niche, temporally and spatially. Productive structure of the community revealed a narrow leaf type which was concentratively distributed in the mid part of community height. The relative light intensity of community ground surface was 6.1%, the leaf inclination 60o,the extinction coefficient(k) 0.4, biomass of community 1,045.6 g.d.w./m2,T/Rratio 9.3, C/Frate 7.0 and sumgermanition, shade toarance and community characteristics on erigeron annuus l.in chejumed leaf area index 3.88. through the various life cycles o e.annuus, we can say that it decreases mortality of seeding caused by some stress and disturbance, for germination lasts for a long time at any opportunity available, and it promotes population growth. The strong shade tolerance of a rosette and the variableness of a life from differentiate the niche between intraspecific and interspecific within the community, and avoid the direct competition between them, thus poromoting community growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.248-252
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• 1999

This study examined the effects of growth retardants and midsummer drainage on lodging-related characters in direct seeding rice culture on flooded paddy surfaces. Treatments included in this study were continuous flooding, two time midsummer drainages (TTD), and inabenfide or trinexapac-ethyl application after TTD. Culm length was reduced most by 11.4cm in trinexapac-ethyl treatment after TTD, followed by 4.1cm in inabenfide treatment after TTD compared to TTD treatment. A significant reduction in culm length occurred at the 3rd internode in inabenfide treatment applied at 40 days before heading (DBH), while trinexapac-ethyl application at 8 DBH reduced the 3rd>2nd>1st internode. The culm diameter of the 4th internode was increased by the application of trinexapac-ethyl following TTD compared to TTD treatment. Thickness of culm wall was significantly increased by trinexapac-ethyl but not by inabenfide applications. Lodging index was the highest in continuous flooding and the lowest in trinexapac-ethyl treatment after TTD. Subsequently, field lodging did not occur in plots treated by trinexapac-ethyl. Rice plants subjected to midsummer drainage or growth retardants showed higher ripened grain ratio and 1000-grain weight, resulting in higher rice yield. These results indicate that trinexapac-ethyl, which can be applied at the relatively later growth stage after proper judgement of lodging occurrence, could be a useful tool for reducing lodging in direct seeding rice culture on flooded paddy fields.

• Current Research on Agriculture and Life Sciences
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• v.23
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• pp.1-8
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• 2005

The purpose of this study was carried out to determine the optimum sowing date and days after sowing (DAS) in automatic facility located at Uiseong of Gyeoungbuk province. The seedling height was rapidly increased with a delay of sowing time from April to May. The 10-day old seedlings with suitable plant height (> l0cm) for machine transplanting in the facility were obtained when the seeds sowed after May 20 at Uiseong in Gyeoungbuk province. The dry weight-height ratio of 10-day old seedlings was significantly decreased when the seeds sowed after June 20, and 15-days old seedlings did after May 10. No. of panicles/hill was reduced with increasing of days after seeding. But there were no significant difference among other yield components such as no. of grains/panicle, ratio of ripened grains, and 1,000 grain weight. The highest grain yield, 748kg/10a, was attained from the 10-day old seedlings transplanted at May 27 in comparision with those of 15-day and 20-day old seedlings. The grain yield of 10-day old seedlings transplanted at June 26 was also higher than that of 15-day old seedlings.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.3
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• pp.95-101
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• 2007

The synthesis of NaA zeolite membrane on a porous alumina support from clear solution by using hydrothermal reaction was investigated. Effects of reaction temperature, reaction time and seeding for transformation of zeolite A membrane and powder which are produced in the reactor were monitored through X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). The transformation process of producing Zeolite A membrane starts from the formation of the compact and continuous membrane on the surface of porous support from clear solution. The large Zeolite A poly-crystal was then farmed through the dissolution process. Finally, the process was advanced from sodalite to amorphous. In case of powder, sodalite is formed in the early stage of reaction because of surrounding space difference between membrane and powder crystal. Discrete surrounding space of powder crystal makes easy to transform to sodalite. From Zeolite A to amorphous through transformed product was rapidly advanced at high temperature while the membrane with somewhat low coverage was obtained at low temperature. A compact and continuous zeolite A membrane was synthesized at $120^{\circ}C$ in 12-hour period.

• Journal of Korean Society on Water Environment
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• v.21 no.1
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• pp.59-65
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• 2005

A phosphate recovery system from artificial wastewater was developed using a completely mixed phosphorus crystallization reactor, in which powdered converter slag was used as a seeding crystal. In preliminary test, the optimal pH range for meta-stable hydroxyapatite crystallization for high phosphorus concentration was observed to be 6.0 to 7.0, which was different from the conventionally known pH range (8.0~9.5) for effective crystallization in relatively low phosphorus concentration less than 5 mg/L. The average phosphorus removal efficiency in a lab-scaled completely mixed crystallization system for artificial wastewater with about 100 mg/L of average $PO_4-P$ concentration was shown to be 60.9% for 40 days of lapsed time. XRD analysis exhibited that crystalline of hydroxyapatite formed on the surface of seed crystal, which was also observed in SEM analysis. In EDS mapping analysis, composition mole ratio (=Ca/P) of the crystalline was found to be 1.78, indicating the crystalline on the surface of seed crystal is likely to be hydroxyapatite. Particle size distribution analysis showed that average size of seed crystal increased from $28{\mu}m$ up to $50{\mu}m$, suggesting that phosphorus recycling from wastewater with high phosphorus concentration can be successfully obtained by using the phosphorus crystallization recovery system.

• Journal of Korean Society of Forest Science
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• v.87 no.4
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• pp.503-509
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• 1998

This research was carried out to promote the seed germination of Styrax japonica, by several pretreatments and to examine its seedling growth and seed component variations according to time and pretreatment. The results are as follows ; 1. Styrax japonica seeds are usually germinated after more than one year cold stratification. However, when the seeds were stratificated for 5 months after dipped in the solution of 70% $H_2SO_4$ for 30 minutes and also treated with $GA_3$(3000ppm), they showed 55% germination. This demonstrated that the seeds could be germinated in one year when pretreated. 2. The growth of one-year-old seedlings after pretreatment was the same as that of two-year-old seedlings when compared 160 days after seeding. 3. Before seeding, one-year-old, pretreated seeds of Styrax japonica showed increased moisture content but decreased crude fat, carbohydrate and exude ash, which were similar to the components of two-year-old seeds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.673-677
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• 1997

It has been reported that E. senticosus is effective for strengthening the liver, reduction of blood sugar levels, antistress and rainforcement of stamina. However, most of the extraction from this medicinal plant is imported from foreign countries. Therefore, farmers have tried to grow it in this country even though it is difficult to propagate by seeding method. This study was carried out to improve seeding propagation using seeds in National Honam Agricultural Experinment Station from '92 to '93. The seeds of E. senticosus were immature embryo at the time of gathering seeds in autumn, and needed wet stratification treatment for after-ripening. Embryo elongated slowly for a few days after stratification treatment, and cotyledon started to develop from 40 days after treatment. There were significantly positive correlation between after-ripening period and the ratio of embryo length. Dehiscence was the highest in the ratio of embryo length of 60∼70％, and percentage of dehiscent seed after treatment for 150 days was 76.5％.