• Journal of the Korean Institute of Landscape Architecture
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• v.20 no.1
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• pp.80-94
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• 1992

To inspect the changing of the forest soil and plants community structrure by air plooutand & acid rain during from September to November in 1990, the smapling sites were selected in the Piwon, Namsan and Kwangnung forest. In sites, plots were set up in Q. aliena forest at Piwon, Quercus mongolica and Pinus densiflora forest at Namsan and Q. mongolica and Pinus densiflora forest at Kwangnung. To obtain the individual number of trees, number of species, importance values and species diversity, using the Curtis & McIntosh methods. The results are following that; 1) In Pinus densiflora community, it was almost dominated by Q. spp. in the canopy layer and P. densiflora and Carpinus laxiflora through the subtree to shrub layer at Kwangnung. It wassaid that C. laxiflora is the climax species in moddle temperature zone. On the contrary, in Namsan forest, there is no appearance thesamplings of P. densiflora & C. laxiflora, but Styrax japonica and Stephanandra incisa that are acid-tolerance species are dominant ones. On the other hand, in Q. spp. community, Q. spp. and C. laxiflora are dominant ones. On the other hand, in Q. spp. community, Q. spp. and C. laxiflora are dominant species through all layer, and in addition C. cordata somewhat appear at Kwangnung. But at Namsan and Piwon forest, Q. mongolica & Q. aliena that were dominant species in canopy layer disappeared in the subtreeand shrub layer, and C. laxiflora and Corunus cordata absolutely disappeared. It were similarly dominated by Robinia pseudo-acacia, Styrax japonica, Sorbus alnifolia, Acer pseudo-sieboldianum, Rhododendrn mucronulatum and so on at Namsn and Piwon forest. In the light of these facts, it found out that disclimax was similar between Namsan and Piwon forest. 2) Species diversity and maximum species diversity were decreased in Kwangnumg, Namsan, Piwon in order. It was xpected that vegetational community was affected by environmental pollutant. 3) As the vegetational community structure analyses, using DCA technique among the ordination, ecological successional series are stopped to Q. spp. from P. densiflora at Namsan and Piwon, but that of Kwangnung is on the way that P. densiflora, Q. alena, C. laxiflora. It was obvi ously different from Namsan and Piwon. 4) In Q. spp. & P. densiflora community, the number of woody plants inNamsan & Piwon is much less than that of Kwangnung through all Layer. Especially, Piwon shown very severe difference. Through all community, the number of individuals of Piwon and Namsan are less than that of Kwangnung. Specially, that of the shrub layer is obvious. 5) In the growth rate of trees, it found out that all sites showed the growth decline phenomena. Especially, since in 1975, there have been the micro disclimax phenomena in Q. community of Kwangnung. 6) In the Q. community, soil acidity of Namsan & Piwon measured 4.57, 4.40 respectively. It was very strong acidity and far lower than that of Kwangnung. Also the content amount of Mg++ in Namsan & Piwon forest were still lower than Kwangnung.

• KSBB Journal
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• v.14 no.2
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• pp.205-211
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• 1999

We investigated optimal conditions for the microbial transformation of $\gamma$-butyrobetaine into L-carnitine by using Achromobacter cycloclast ATCC 21921. When the cells were cultivated in the medium containing $\gamma$-butyrobetaine as the sole carbon source for both cell growth and L-carnitine production, the maximum L-carnitine production was 2.9 g/L and the conversion yield from $\gamma$-butyrobetaine to L-carnitine was as low as 30.9 mol%. In order to enhance the L-carnitine production and the conversion yield, various carbon sources were added to the $\gamma$-butyronetaine containing basal medium. In the medium supplemented with glycerol, L-carnitine production was as high as 4.6 g/L and the conversion yield was 88.2 mol%, showing a significant improvement in L-carnitine synthesis compared to those in the medium without glycerol. We also examined the additional effect of quaternary ammonium compounds such as betaine and choline, which are similar in structure to $\gamma$-butyrobetaine and L-carnitien. It was observed that in the presence of those quaternary ammonium compounds, both the L-carnitine production rate and the conversion yield increased. In addition, we found that cell growth was inhibited by a $\gamma$-butyrobetaine concentration of more than 3%, while L-carnitine production was efficient at the $\gamma$-butyrobetaine concentration of 2-3%. By cultivating the cells in the optimal medium containing glycerol and choline, we obtained an L-carnitine concentration of 7.2 g/L with the conversion yield of 98.7 mol% in 4 days.

• Korean Journal of Materials Research
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• v.4 no.6
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• pp.687-694
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• 1994

Heteroepitaxial InP/GaAs layers were grown using the selective liquid phase epitaxy (SLPE) technique. It was observed that the optimum LPE conditions were $660^{\circ}C$ growth temperature, $5^{\circ}C$ supercooling, and $0.4^{\circ}C$/min cooling rate. Maximum expitaxial layer overgrowth (ELO) of 110-160$\mu \textrm{m}$ was obtained when the seed was aligned along (112) orientation. Initial melt-back of the substrate was observed but limited to the seed region so that flat In-Ga-As-P layers were grpwn throughout the GaAs substrates. The InP/GaAs heteroepitaxial structure could be obtained by growing an additional InP layer on top of the In-Ga-As-P layer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.4
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• pp.301-306
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• 1992

In order to determine the optimal conditions for the process of acetic acid fermentation, the kinetics of Acetobacter aceti fermentation in submerged batch cultures were studied at different agitation speeds and air flow rates. The maximum cell concentration was noted after about 48 hr fermentation and the time course of Acetobactey aceti fermentation showed a distinct feature of growth-associated product formation. At agitation speeds 700, 500, and 300 rpm fixed on air flow rate 1 v/v/M, specific grow rates were $3.97\times10^{-2},\;3.82\times10^{-2},\;and\;2.04\times10^{-2\} \;hr^{-1}$, saturation constants were 61.4, 64.6, and 69.4mg/ml. and volumetric oxygen transfer coefficients were 0.9337, 0.4468, and 0.1701 $min^{-1},$ respectively. At air flow rates 1.25, 1.00, and 0.75 v/v/M fixed on agitation speed 500 rpm, specific growth rates were $3.90\times10^{-2},\;3.82\times10^{-2},\;and\;2.37\times10^{-2}\;hr^{-1}$, saturation constants were 63.4, 64.6, and 64.9 mg/ml, and volumetric oxygen transfer coefficient were 0.4923, 0.4468, and 0.3509 $min^{-1},$ respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.206-214
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• 2011

Fifteen clones of poplars, 2 clones of willows, and yellow poplar were used to evaluate the effects of 5 treatments such as SCBLF (slurry composting and biofiltration liquid fertilizer), general slurry liquid fertilizer, chemical fertilizer, groundwater, and control (no treatment) on vitality, growth performance, and biomass production. Five cuttings for each tree species were planted in 3 replications. After planting cuttings, a coppice was induced by cutting off stems at 10cm above the ground. Data were collected for first growing season and trees were harvested at the end of October. Maximum mortality rate i.e. 96% was recorded in the cuttings treated with groundwater and minimum 92% with control (no treatment). In all tree species, sprouting of stump was not differ significantly among the treatments. Total nitrogen concentrations of leaves and stump sprouts were higher in the treatment of SCBLF than the control, 26.6% and 22.9%, respectively. Biomass production was highest in the stumps treated with chemical fertilizer, $1.98Mg\;ha^{-1}\;year^{-1}$, and lowest in control ($1.34Mg\;ha^{-1}\;year^{-1}$).

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.6
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• pp.225-231
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• 2016

The valence band maximum (VBM) and conduction band minimum (CBM) of Al-doped GaInAsSb alloys substrated on GaSb are calculated by using an analytic approximation based on the tight binding method. The relative positions of the VBM and CBM between Al-GaInASSb and GaSb determine band alignement type, valence band offset (VBO) and conductin band offset (CBO) for the heterojunctions. In this study, aluminium doping is assumed to be substituted in the cation site and limited up to 20 % because it can easily oxidize and degrade materials. It is found that the Al-doped alloys exhibit type-II band alignments over the entire composition range and make the band gaps increase, whereas the VBO and CBO decrease. The decreasing rate of VBO is higher than that of CBO, which implies the Al components play a decisive role in controlling electrons at the interface. The Al-dopled GaInAsSb alloy has a direct band gap induced by $E({\Gamma})$ with a considerable distance from the E(L) and E(X), however, $E({\Gamma})$ approaches to E(L) and E(X) in the high Sb concentration (Sb > 0.7-0.8) which might affect the electron mobility and degrade the optical quality.

• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.25-33
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• 1998

Root zone temperature have influenced on protected cultivation in winter season. Especially root zone temperature is acted on limiting factor in crop cultivation. This study was conducted to obtain optimum temperature of root zone in Protected cultivation Root zone was warmed by heated water($28^{\circ}C$) flowing through the PPC pipe(${\phi}15$) buried depth 40 cm. And the flowing water was heated by solar system. Minimum air temperature during night time was set at $14^{\circ}C$ and maximum air temperature during day time was set at $28~30^{\circ}C$ the growing period of cucumber was from Nov. 6, 1996 to Jan. 30, 1997. The results are summarized as follows. 1. Average soil temperature at 15~20 cm depth was $22^{\circ}C$ at warming plots, $17~18^{\circ}C$ at non-warming plots 2. Early growth in leaf length, stem diameter, number of leaves and leaf area for 30 days after planting were accelerated by root zone warming. Especially, the grawing rate of soil warming plots was higher 27% in leaf length, 51% in leaf number, 150% in leaf area than non-warming Plots. Above-ground and underground part of warming plots was higher 117%, 56% than non-warming plots. 3. In total yield analysis, number of fruits were 614 in soil warming and 313 in non-warming plots. In the result, total yield of soil warming plots was increased with 196% than non-warming plots. 3. In total yield analysis. number of fruits were 614 in soil warming and 313 in non-warming plots. In the result. total yield of soil warming plots was increased with 196% than non-warming plots.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.33-39
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• 2014

One hundred forty four bacterial colonies which were able to degrade crude oil were isolated from soil samples that were contaminated with oil in Daejeon area. Among them, one bacterial strain was selected for this study based on its emulsification activity, growth rate and surface tension activity, and this selected bacterial strain was identified as Pseudomonas sp. HN37 through physiological- biochemical tests and analysis of its 16S rRNA sequence. Pseudomonas sp. HN37 utilize the several aliphatic hydrocarbons, 3,5-dinitrosalicylic acid and 2,4-dichlorophooxyacetic acid as a sole carbon source. And this bacterial strain showed a high resistance to antibiotics such as ampicillin and chloramphenicol, as well as heavy metals such as Ba, Cr, Li and Mn. Also, it was found that the optimal pH and temperature for the cell growth, surface tension, and emulsification activity of Pseudomonas sp. HN37 were pH 6.0-9.0 and $30^{\circ}C$, respectively. The emulsification and surface tension activity was reached the maximum to 1% (V/V) crude oil and 1% (W/V) NaCl concentration. The surface tension of the culture broth was decreased from 62 to 27 dyne/cm after fifteen hours of inoculation in LB media.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.556-560
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• 1997

The removal efficiency of COD and the production of ${\delta}-aminolevulinic$ acid (ALA) were concurrently investigated for both purifying the soybean curd wastewater of high BOD and utilizing the wastewater as a renewable substrate of ALA production using Rhodobacter capsulatus KK-10. Its wastewater was a favorable media for the growth of photosynthetic bacteria in terms of its environmental characteristics having COD/BOD rate of 0.98, ratio of BOD : N : P=100 : 6 : 4, BOD/N ratio of 17.2, lactic acid of 1,080 ppm. Its COD value wastewater was decreased to 94% and dry cell weight was approached to about 1.2 g/l after cultivation of the photosynthetic bacteria for 4 days. By the addition of 15 mM levulinic acid (LA) into the wastewater at the middle log phase of cell growth, the amount of ALA secreted was 55 mg/l. The ALA production was considerably increased to 114 mg/l under the cultural condition of 15 mM supplementations of glycine and succinate with LA at the same period. Furthermore the maximum ALA production of 120 mg/l and COD removal efficiency of 92% were accomplished in the soybean curd wastewater enriched with one addition of 15 mM LA and three serial additions 15 mM ALA precursors.

• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.272-277
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• 2010

To replace current expensive photobioreactor, this study was conducted to develop low-cost photobioreactor made of polyethylene bag. In previous study, optimal culture conditions of Spirulina platensis NIES 39 have been established, and based on these, the study of biological carbon dioxide fixation has been conducted. The maximum growth was the biomass 2.677 g/L at conditions of 10% $CO_2$, 0.1 vvm. It was shown that $F_{CO_2}$ was 4.056 g $CO_2$/L and $R_{CO_2}$ was 0.312 g $CO_2$/L/day. But, compared with the data at conditions of 5% $CO_2$, 0.1 vvm, $FE_{CO_2}$ was shown 52.372% which is half of it. Regarding the effect of $CO_2$ following illumination, the growth revealed that the input conditions, for 10 min per 3 h, were excellent in the light. $CO_2$ in absent light. $CO_2$ concentration and flow rate were 5% $CO_2$, 0.1 vvm, respectively. Finally, the addition of $CO_2$ was ineffective in the absence of light.