• Korean Journal of Microbiology
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• v.50 no.2
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• pp.164-168
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• 2014

The ecosystem of the Arctic region has been increasingly affected by global warming. Archaeal ammonia monooxygenase alpha subunit coding gene (amoA) which is a key enzyme for nitrification was used to investigate the effect of runoff water of ice melt on microbial community of nitrogen cycle. The archaeal amoA genes at coastal area of Svalbard, Arctic region were PCR-amplified and sequenced after clone library construction. Analysis of archaeal amoA gene clone libraries suggested that the station 188 which is in the vicinity to the area of runoff water harbor lower ammonia-oxidizing archaeal diversity than the station 176 and 184. The average amino acid sequence identity within all archaeal amoA gene clones was 94% (with 91% nucleotide sequence identity). While all the clones of the station 188 were affiliated with Nitrosoarchaeaum clade containing strains isolated from low-salinity and terrestrial environments, about 45% of total clones of the station 176 and 184 were related to marine Nitosopumilus clade. Interestingly, other typical archaeal amoA gene clones of thaumarchaeal I.1b clade frequently retrieved from terrestrial environments was identified at station 188. Microbial community of nitrogen cycle in marine sediment might be affected by input of sediments caused by runoff glacier melt waters.

• Journal of Plant Biotechnology
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• v.35 no.4
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• pp.275-280
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• 2008

One of the limitation for Agrobacterium-mediated transformation via organogenesis from cotyledon explants routinely in cucumber is the production of chimeric plants. To overcome the limitation, Agrobacterium-mediated transformation system via somatic embryogenesis from hypocotyl explants of cucumber (c.v., Eunsung) on the selection medium with paromomycin as antibiotics was developed. The hypocotyl explants were inoculated with Agrobacterium tumefaciens strain EHA101 carrying binary vector pPTN290; then were subsequently cultured on the following media: co-cultivation medium for 2 days, selection medium for $5{\times}14$ days, and regeneration medium. The T-DNA of the vector (pPTN290) carried two cassettes, Ubi promoter-gus gene as reporter and 35S promoter-nptll gene conferring resistance to paromomycin as selectable agent. The confirmation of stable transformation and the efficiency of transformation was based on the resistance to paromomycin indicated by the growth of putative transgenic calli on selection medium amended with 100mg/L paromomycin, and GUS gene expression. Forty eight clones (5.2%) with GUS gene expressed of 56 callus clones with resistance to paromomycin were independently obtained from 928 explants inoculated. Of 48 clones, transgenic plants were only regenerated from 5 clones (0.5%) at low frequency. The histochemical GUS assay in the transgenic seeds ($T_1$) also revealed that the gus gene was successfully integrated and segregated into each genome of transgenic cucumber.

• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.391-398
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• 1997

Present study describes a method on the application of efficient tissue culture systems for the micro-propagation of juvenile and mature sawtooth oak(Quercus acutissima). Nodal segments with axillary buds were used as initial explant sources. WPM(Woody Plant Medium) was the best in growth and proliferation of shoot among the media tested. Although the single effect of zeatin revealed on two dorminant shoot elongation with normal growth until the elevation of levels up to 3.0mg/l, BAP($N^6$-benzyl amino purine) usually showed better response than zeatin on shoot multiplication and/or elongation. In addition, the incorporation of BAP and zeatin onto the culture media represents more effectiveness in shoot proliferation and its growth. Optimum concentrations of BAP and zeatin were 0.5 and 0.05~1.0mg/l, respectively. Ninety percent of the proliferated shoots was rooted on half-strength GD (Gresshoff and Doy, 1972) medium containing 0.5mg/l IBA(indole butyric acid) in 4 weeks after culture. More than 70% of the rooted plantlets survived after 5 months of transplanting into artificial soil mix containing equal amount of peatmoss and perlite. Among 27 plus tree clones which were grafted twice onto the juvenile rootstocks, only 4 clones revealed the possibility for shoot multiplication through tissue culture system. The capacity for the micropropagation using mature explant sources was highly depended on clonal differences compared with those of octet age. More than 90% of rooting ratio was obtained from the best responding clone. Among the 7 rooting media tested, GD medium was the best far rooting. The most effective rooting was obtained on half-strength GD medium containing 0.2 to 2.0mg/l IBA. More than 60% of rooted plantlets survived after 5 months of transplanting into the artificial soil mix.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.205-210
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• 1994

This study was conducted to develop a method of mass production by cutting of superior genotypes of Larix leptolepis and to examine the effects of ortet age, clone, crown position, and an applied plant growth substance upon the rooting of cuttings. Four different ortet ages, 2, 8, 16 and 30 years and three levels of root-promoting substances, indole butyric acid(IBA), at 1000, 2000, and 5000ppm were employed. Greenwood cuttings were taken from mother trees in late July and rooted for three months in rooting medium containing peatmoss : vermiculite : perlite(1 : 1 : 1 by volume). with temperature controlled at $20-25^{\circ}C$, humidity by intermittent misting and light by partial shading in the greenhouse. Cuttings treated with 1000ppm IBA showed highest rooting, with 80%, 71%, 52%, 25% for 2-, 8-, 16-. 30-year-old ortet, respectively. Untreated cuttings showed rooting of 52%, 48%, 36%, 20% for the ortet age of 2, 8, 16, 30 years, respectively. The average number of adventitious roots decreased with increasing ortet age from 2 to 30 years, whereas IBA treatment increased the number of roots in all ages. A variation in rooting among 20 clones tested was observed. The 4 clones, Chungnam 6, and 7 and Chonbuk 1, and 9 showed good rooting of about 67%, while Kangwon 49 showed boor rooting of 40% at 1000ppm IBA treatment. When crown position was compared, cuttings taken from middle crown showed highest rooting of 60%, while cuttings from upper crown showed lowest rooting of 53%.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.5
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• pp.491-498
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• 2010

Humidification of PEM fuel cells is necessary for enhancing their performance and lifetime. In this study, a humidification system was designed and tested; the system includes an air-supply tube (inner diameter: 75 mm) through which a nozzle can be directly inserted and a cyclonic separator for the removal of water droplets. Three types of nozzles were employed to study the influence of injection pressure, air flow rate, and spray direction on the humidification performance. To evaluate the humidification performance, the concept of humidification efficiency was defined. In the absence of an external heat source, latent heat for evaporation will be supplied by the own enthalpies of water and air. Thus, the amount of water sprayed from the nozzle is the most critical factor affecting the humidification efficiency. Water droplets were efficiently removed by a cyclonic separator, but re-entrainment occurred at high air flow rates. The absolute humidity and humidification efficiency were $21.29\;kJ/kg_{da}$ and 86.57%, respectively, under the following conditions: nozzle type PJ24; spray direction angle $90^{\circ}$; injection pressure 1200 kPa; air flow rate 6000 Nlpm.

• Journal of Plant Biotechnology
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• v.39 no.3
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• pp.196-204
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• 2012

This study was carried out to develop reliable systems for somatic embryogenesis in oil palm tree (Elaeis guineensis Jacq.), and to verify the somaclonal variants by RAPD analysis. Embryogenic callus was induced successfully on modified half-strength MS medium containing $NaH_2PO_4{\cdot}2H_2O$ and casein. Embryogenic callus was further developed to somatic embryo mass (SEM), which is very hard and bonded tightly each other. Plantlets were proliferated when SEM was cultured on modified MS medium containing half strength $NH_4NO_3$, casein and L-ascorbic acid. Plantlets were transplanted into pots containing artificial soils. When RAPD analysis was conducted using randomly selected 95 in vitro plantlets and 19 random primers, somaclonal variation was detected using BNR35 primer. There was missing band around 1 kb in #22, #28, #35, and #77 plantlets. In addition, bands obtained from #28, #35, and #77 was much stronger than other normal bands. The blast results at NCBI revealed that somaclonal variation observed in this study was related to chloroplast genome of oil palm. The results also revealed that oil palm reproduction system through somatic embryogenesis is quite reliable and early detection of somaclonal variants seem to be possible at in vitro stage by RAPD analysis.

• Journal of the Korea Society of Computer and Information
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• v.18 no.1
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• pp.149-156
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• 2013

In this paper, Commercial program, STAR-CCM+, was used for computer simulation. And also Multi Inner Stage(MIS) cyclone which especially designed for the real experiments of particle removal efficiency. Under negative pressure condition of outlet, computer simulation was performed to predict the removal efficiency for $5{\mu}m$ and $10{\mu}m$ particles by using a turbulence model and lagrangian method. The simulation results are 55.7% and 64.1% for $5{\mu}m$ and $10{\mu}m$ particles, respectively. To compare the simulation results with the actual test of MIS cyclone, we generated the $SiO_2$ particles by heat reactor. Although removal efficiency of actual tests is 63~76% at different flow rate, the size of $SiO_2$ particles which confirmed by SEM(scanning electron microscope) and WAPS(wide range aerosol particle spectrometer) is too small(15~30nm) to compare each results. And so the alternative experiments were performed by using commercial alumina particles ($5{\mu}m$, $10{\mu}m$ and $20{\mu}m$). It was shown that the actual removal efficiency, 76~95%, from MIS cyclone is higher than simulated one.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.21 no.1
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• pp.53-66
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• 1995

The gene for ${\gamma}$-casein, a milk protein, is a member of a family of casein gene which is expressed in mammary glands of the animal during the late gestation and lactation periods binder the influence of various hormones. In order to elucidate tile mechanisms b)'which hormones regulate the coordinate induction of milk protein genes, the mouse ${\gamma}$-casein gene was isolated and characterized. The ${\gamma}$-casein gene was screened from a mouse genomic library constructed in bacteriophage EMBL3 with the ${\gamma}$-casein CDNA used as probe and one clone was obtained. The ${\gamma}$-casein CDNA as probe was partially sequenced and contained ATG start codon and 5'-noncoding region. The cloned genomic DNA was digested with Sal I restriction enzyme, by which the insert DNA can be isolated from EMBL3 vector. Three DNA bands were observed and the size of DNAs was approximately 28kb, 14kb and 9Kb, respectively Accordingly the size of the insert DNA was calculated with approximately 23Kb. The result of Southern blot analysis, however, showed that the cloned genomic DNA was not hybridized with the synthetic oligonucleotides (40 mer) of cDNA 5'-end region, but it was hybridized with the y -casein CDNA. This means that tile cloned y -casein gene may not contain its promoter region. The ${\gamma}$ -casein genomic DNA containing the promoter region has been screening from mouse genomic library with oligonucleotides of CDNA 5'-end region as probe, and twenty-nine clones was obtained.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.194-199
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• 2005

The principle of vortex cyclone was applied to enhance the treatment efficiency of waste air streams containing particulate matters, phenol, and others. Adsorption, condensation, and/or coagulation could be induced at low temperature zone formed by Joule-Thomson expansion as the pressurized air and pulverized activated carbon were introduced at the tangential direction into the cyclone system applied with the coaxial funnel tube of vortex cyclone. Easily condensible vapors were adsorbed and/or condensed forcibly on coagulated or condensed materials which were formed as cores for coagulation or condensation by themselves or on pulverized activated carbons. These types of coagulation or condensation rates were rapidly promoted by increase in their diameter. The maximum removal efficiency obtained from this experiment for the removal of carbon dioxide and phenol was about 87.3 and 93.8 percent, respectively. Phenol removal efficiency was increased with the relative humidities and enhanced by pulverized activated carbon added. The Joule-Thomson coefficients were increased with the pressure of air injected in the range of the relative humidities between 10% and 50%. It is believed that the moisture, particulate matters, and the pressure of the process air introduced could control the removal efficiency of VOCs.

• Journal of Korean Society of Forest Science
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• v.79 no.2
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• pp.109-114
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• 1990

The axillary buds of 15-year-old Tilia amurensis were cultured on Saito and Ide (IS), Murashige and Skoog (MS) media and woody plant medium (WPM) to establish an effective micropropagation method. Five levels of 6-benzylaminopurine (BAP) were tested. On IS medium and WPM addition of 1.0/l BAP enhanced shoot development and shoot elongation, whereas addition of 0.5/l BAP was effective on MS medium. A better results were obtained from WPM with 1.0/l BAP and MS with 0.1/l BAP. Developed shoots were subcultured on each basal media but with 0.2/l BAP, Multiple shoots were almost doubled in a month. Root formation could be enhanced at higher concentration of indole-3-butyric acid (IBA). Better rooting rate (83.3%) was achieved on a half-strength MS medium with 3.0 /l IBA. Regenerated plantlets were successfully transferred to soil. To investigate the clonal variation in shoot development and shoot elongation by axillary bud culturing, seven plus tree clones were tested, Clonal variation in tissue culturability among plus trees was recognized by the Duncan's multiple range test at the 5% level. Kang Won No. 12 showed the best response on WPM with 1.0/l BAP.