• Journal of the Korean Vacuum Society
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• v.15 no.2
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• pp.223-230
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• 2006

We have investigated the characteristics of hydrogen (H) plasma treated quantum dot infrared photodetectors (QDIPs). The structure used in this study consists of 3 stacked, self assembled $In_{0.5}Ga_{0.5}As/GaAs$ QD layer separated by GaAs barrier layers that were grown by molecular beam epitaxy. Optical characteristics of QDIPs, such as photoluminescence (PL) spectra and photocurrent spectra, have been studied and compared with each other for the as grown and H plasma treated QDIPs. H plasma treatment, resulted in the splitting of PL peak, which can be attributed to the redistribution of the size of QDs. The activation energies estimated from the temperature dependence of integrated PL intensity for as grown and H plasma treated QDIPs are found to be in good agreement with those determined from corresponding peaks of photocurrent spectra. It is also noted that photocurrent is detected up to 130 K for the H plasma treated QDIP, suggesting the future possibility for the development of infrared photodetectors with high temperature operation.

• 전자공학회논문지 IE
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• v.45 no.3
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• pp.1-4
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• 2008

We investigate magnetic semiconductor thin films for application towards spintronics, which can overcome current limitations in semiconductor devices. GaMnAs magnetic semiconducting films studied are easily integrated into conventional semiconductor processes and also offer a wide range of application, therefore it shows much promise as a future material. However the Curie temperature at which magnetic properties exist for GnMnAs is very low, also depending on deposition conditions the properties of the film can vary widely. In order to study these issues we investigate the best possible deposition conditions for magnetic properties.

• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.215-220
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• 1994

Pollen-derived embryos cultured on the hormone-free medium showed a low germination frequency (12.5%) and poor growth response after germination. The greatest frequency of germination (81.3%) was obtained from the embryos cultured on medium with 0.3mg/L GA$_3$.The greatest frequency of generation (81.3) was obtained from embryos cultured on medium with 0.3mg/L GA$_3$. The embryos precultured for 20 days on medium with 0.3mg/L GA$_3$were transferred to the medium with various combination of hormones such as IAA, kinetin, zeatin, 6-benzylaminopurin (BA) and Gh$_3$. The germination frequency of cotyledonary stage embryos showed above 72% on media with all of the hormonal combinations, but the embryos germinated on medium with 2mg/L BA or 0.1mg/L kinetin and 0.3mg/L GA$_3$ developed more vigorously into plantlets than those of other hormonal combinations. Torpedo-stage embryos cultured on medium with 0.3 mg/L Gh$_3$ were pretreated for 8 weeks at 2-week intervals at 4$^{\circ}C$, The germination frequency of the cold-preheated embryos increased with the increment of pretreatment period from 2 to 8 weeks. The greatest frequency of germination (73.3%) was obtained from the embryos pretreated for 8 weeks at 4$^{\circ}C$. The chromosomes of the root-tip cells of W plane grown for 40 days after germination were observed. Most of the regenerated plants were haploid (55.8%) or diploid (315%), but triploid (1.3%), tetraploid (5.2%), or aneuploid (6.5%) were also detected among them.

• Korean Journal of Environment and Ecology
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• v.9 no.1
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• pp.56-61
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• 1995

To examine the effects of gibberelin treatment on seed germination of six wild herbaceous species -Dicentra spectabilis, Aster pekinensis, Agastache rugosa, Elsoholtzia ciliata, Boehmeria tricuspis and Pulsatillia cerrma var. chaerophyiloides - in Kangwon-do, pretreated seeds of five species were sowed on plastic pots with mixed soil(sand：peat moss：perlite： vermiculite, 1：1：1：1, v/v) in 23,April 1995. Seeds were soaked in 25,50 ppm gibberelin solution and ground water during 24 hours. Pretreated seeds of Pulsatiilia cerrma var. chaerophylloides were sowed on nursery soil in 1, June 1995. Seed pretreatments in 31, May 1995 were same method. Seed germination rate was measured and compared among species and treatments. Seed germination rate of Dicentra spectabilis, Agastache rugosa and Elsoholtzia ciliata was differed higly significant among pretreatments ,but those of that of Aster pekinensis, Boehmeria tricuspis and Pulsatillia cerrma var chaerophylloides did not significant at 5% level. Gibberelin pretreatment raised seed germination rate of Dicentra spectabilis and Agastaohe rugosa and proper concentration of GA$_3$ was 25ppm and seed germination rate of Elsoholtzia ciliata was highest at GA$_3$ 50ppm plot. The utilization of wild herbaceous species were discussed.

• Korean Journal of Medicinal Crop Science
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• v.9 no.2
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• pp.99-107
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• 2001

Germination of Codonopsis pilosula seeds and afterward their seedling emergence have been occasionally very poor due to their dormancy and structural defects. The study was done to determine the treatment effects of priming, $GA_3$, agitation and washing during and after priming, drying and water imbibition after drying on germination of its seeds and then of the successive three combined treatment after priming on the its seedling emergence to model its presown seed treatment. While agitation at the speed of 10 rpm was made or not, priming using $Ca(NO_3)_2$ and $GA_3$ under their different concentrations and light quality illuminated for 12 hours a day were done separately. Then their two best results were compared to determine the better one. Using the above determined best result, washing was done 3 minutes in the tap water or not, and drying of washed seeds was made under 4 different lights, and water imbibition of the dried seeds with differed period were successively done to deduce its presown seed treatment. In the comparison of the best germination rate of priming and $GA_3$, the former showed considerably higher rate than the latter; the priming treatment was done at agitated $Ca(NO_3)_2$ 150 mM solution under darkness or 12 hour red light illumination a day for 2 days. Washing after priming enhanced the rate compared to no-washing. Drying was the best way at which seeds washed were desiccated under $35^{\circ}C$ and 4 hour red light illumination. Water imbibition immediately before sowing must be made for 2 days. Seedling emergence rate was the highest at the seeds from successive 4 treatments, priming, washing, drying and water imbibition before sowing of two others, the priming and washing, or the priming, washing and water imbibition, meaning that its presown seed treatment must follow the procedure of the above 4 successive ones.

• Journal of Life Science
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• v.24 no.8
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• pp.887-894
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• 2014

The screening of the microorganisms degrading chlorinated organic compounds such as PCP (pentachlorophenol) and TCE (trichloroethylene) was conducted with soil and industrial wastewater contaminated with various chlorinated organic compounds. Isolates (GP5, GP19) capable of degrading PCP and isolates (GA6, GA15) capable of degrading TCE were identified as Acetobactor sp., Pseudomonas sp., Arthrobacer sp., Xanthomonas sp. and named Acetobacter sp. GP5, Pseudomonas sp. GP19, Arthrobacer sp. GA6 and Xanthomoas sp. GA15, respectively. The microbial augmentation, OC17 formulated with the mixture of bacteria including isolates (4 strains) degrading chlorinated organic compounds and isolates (Acinetobacter sp. KN11, Neisseria sp. GN13) degrading aromatic hydrocarbons. Characteristics of microbial augmentation OC-17 showed cell mass of $2.8{\times}10^9CFU/g$, bulk density of $0.299g/cm^3$ and water content of 26.8%. In the experiment with an artificial wastewater containing PCP (500 mg/l), degradation efficiency of the microbial augmentation OC17 was 87% during incubation of 65 hours. The degradation efficiency of TCE (300 uM) by microbial augmentation OC17 was 90% during incubation of 50 hours. In a continuous culture experiment, analysis of the biodegradation of organic compounds by microbial augmentation OC17 in industry wastewater containing chlorinated hydrocarbons showed that the removal rate of COD was 91% during incubation of 10 days. These results indicate that it is possible to apply the microbial augmentation OC17 to industrial wastewaters containing chlorinated organic compounds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.141-148
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• 1992

Field experiment was carried out to investigate the effect of plant growth regulator (PGR); IAA, GA, Kinetin to regrowth of sorghum and pearlmillet according to variety and plant growth stage. Kinetin application after cut increased tiller number and decreased dry weight of regrowth, but its application on sorghum stubble in water stress increased tiller number and leaf elongation rate, consequently increased regrowth dry weight. GA application reduced tiller production in both species, but tiller formation in pearlmillet was decreased more than in sorghum by promoting leaf elongation of old tiller. Nonstructural carbohydrate (NSC) of stubble during regrowth was consumed less at anthesis than at stem elongation stage because of senescence of tiller primordia. GA treatment reduced NSC content more than other PGR in both plant species, by consuming reserve NSC and stimulating rapid elongation of old tiller after cut. Dry matter increase during regrowth had high correlation with tiller number and tiller elongation a week after cut, while it did not have any correlation with NSC at cutting stage or with consumption of NSC during regrowth. Therefore, regrowth in sorghum and pearmillet must depend upon activity of tiller primordia more than upon amount of reserved NSC.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.2
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• pp.71-76
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• 1998

To define the relations between endogenous GA levels and growth and flowering in short-day plant sorghum, growth retardant BX-112 was applied to two sorghum genotypes, wild-type and phytochrome B mutant (phyB-1), which grows faster and flowers earlier than the wild-type. BX-112 and $GA_3$ were applied as a soil drench, and plant height, culm length, and date to floral initiation were investigated. Endogenous GAs contents were measured with GC-MS-SIM. BX-112 treatments inhibited shoot growth in both genotypes and drastically reduced $GA_1$ and $GA_8$ levels. With increasing BX-112 concentrations, $GA_1$ concentrations declined linearly, but caused the accumulation of intermediates from $GA_12$ to $GA_20$. This result implies that $GA_1$ is the major active endogenous GA in shoot elongation in a short day plant sorghum. The inhibition of plant growth in both of wild type and phyB-1 by BX-112 was very similar, while BX-112 effects on floral initiation in two types of plants differed significantly. Floral initiation of phyB-1 was not affected by BX-1l2, but that of wild-type was delayed as BX-1l2 concentration increased. Because BX-112 treatment causes accumulation of biosynthetic intermediates between synthetic pathway from $GA_12$ to $GA_20$ and because phyB-1 is altered in GA metabolism in this same region of the early C13-hydroxylation pathway, BX-112 may fail to block flowering of phyB-1.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.1
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• pp.75-84
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• 2011

This study was conducted to provide a basic information for the establishment of operation and treatment processes in sewer system of Nakdong river basin to minimize the overall pollutants loading to water body. Sewage flowrates were regularly measured and monitored at various sampling points of newly-built separated sewer system located in G City GA sites. To assess the inflow sewage flowrate, various calculating methods such as water-use evaluation, average-minimum daily flow quality evaluation, minimum daily flow evaluation, night water-use evaluation were used. Average I/Is were calculated except water-use evaluation. Average I/Is were found to be 6.5 $m^{3}/d$, 3.5 $m^{3}/d$, 7.7 $m^{3}/d$ at GA-1, GA-2, GA-3 points respectively. I/I ratios of three areas were found to be 4.8 %, 2.0 % and 2.7 % respectively and were obviously lower than those of the other separated sewer systems as shown in the previous studies.

• Development and Reproduction
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• v.5 no.1
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• pp.23-33
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• 2001

When mammalian oocytes ovulate into the oviduct, associating follicular fluid components are exposed to the oviductal environment, possibly resulting in the mutual interaction between fillicu1ar and oviductal fluids. In the Present study, we have demonstrated for the first time that components of fallicular fluid could be modified by the oviductal fluid. Gelatin zymographic analyses of human follicular fluid (hFF) obtained from IVF patients showed consistently the presence of 110 kDa gelatinase (GA110) in addition to many bands among which 62 kDa gelatinase was predominant. Addition of EDTA or phenanfhroline to the gelatinase substrate buffer during gel incubation abolished GA110 band whereas phenylmethylsulffnyl fluoride (PMSF) did not. In contrast, bovine oviductal fluid(bOF) exhibited only 62 kDa gelatinase. Surprisingly, when bOF was added to hFF in 1:1 ratio and then the mixture was incubated for 3 h at 37$^{\circ}$C, GA110 of hFF disappeared. Disappearance of GA110 by bOF was observed even within 30 min after mixing with hFF. Addition of aminophenylmercuric acetate (APMA) to hFF also abolished enzymatic activity of GA110 but increased the activityof 62 kDa gelatinase. However, APMA abolished many other gelatinases as well unlike bOF. Interestingly, treatment of hFF with EDTA for 3 h remarkably increased the enzymatic activity of GA110 but not that of other gelatinases. Addition of phenanthroline, PMSF or soybean trypsin inhibitor (SBTI) did not affect overall gelatinase activities. Again, addition of bOF to the hFF pretreated with any of the above proteinase inhibitors abolished the appearance of GA110. Human serum also showed GAI 10 of which activity was greatlyenhanced by EDTA treatment. Similar to hFF, serum GA110 also disappeared by the addition of bOF. Human granulosa cell homogenate did not reveal any appreciable gelatinase activity except 92 kDa gelatinase. Anti-human gelatinase A antibody reacted with 62 kDa gelatinase of hFF. Based upon these results, it is concluded that bOF could selectively degrade an isoform of gelatinase A present in hFF and human serum.