• KSBB Journal
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• v.16 no.4
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• pp.403-408
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• 2001

Distillation condensate generated from downstream processing of microbial alcohol fermentation imposes a serious burden to biological wastewater treatment or anaerobic digestion due to its high contents of SS (suspended solids) and TN (total nitrogen), A pilot scale microfiltration of the stillage condensate with a stainless steel SCEPTER membrane of 0.1 ${\mu}$m pore size was carried out to remove SS which was mostly composed of microbial cell residue. A stable permeate flux was achieved when the decanter effluent containing 0.7% of SS was filtered under the conditions of X10 VCR (volume concentration ratio), 2.5 bar of TMP (transmembrane pressure), and 60$^{\circ}C$. When stillage condensate with 2.6% SS was treated directly with microfiltration, VCR below X3 was recommended for a long duration of filtration. The permeate and retentate obtained from microfiltration were recycled to make-up medium of fermentation. Adding permeate or retentate up to 30% of fermentation volume showed no distinguished undesirable influence during the course of alcohol fermentation. Although only slight improvements in the final amount of CO$_2$ evolution and alcohol content were observed, fermentation rate increased so that the required time to reach 450 L/ton of CO$_2$ evolution was shortened to 72% of that with normal media.

• Journal of Ginseng Research
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• v.20 no.3
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• pp.291-298
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• 1996

Free amino acid (FAA) compositions in the central part (pith-xylem : P-X) and the outer part (phloem-cortex : P-C) of root were investigated for P ginseng (P.g), p. quinque-folium (P.q) an, B P nutoginsen (P.n) by an amino acid analyzer. Total free amlno acids content (TFAA) was highest in p.맥 and lowest in p.n. The TFAA of P-Xs were higher than those of P-Cs in these Panax species except p.n. The higher the TFAA in P-X, the higher the ratio of TFAA in P-X to that in P-C. Seven- teen free amino acids and ammonia were identified, and four unknown peaks appeared before the usual amino acids eluted. The total aspartic acid equivalent of these unknown peaks was corresponded to 77% of known TFAA in P-C of p.n, 17% in P. n, and 7% in p.q. The pattern of unknown peaks of p.g was different from p.q and similar to P.n. In all samples six major amino acids and ammonia accounted for 90~95% of TFAA. Arginine was comprised from 29% (P.n) to 43% (P.g) by amole as amino acid and from 50 to 71% by amole as nitrogen (N amole) in TFAA. Ammonia was the second abundant one by amole and the third by Npmole. Histidine was the second by Npmole. Praline was one of major FAA in p.q. Pattern similarity of FAA composition (excluding Arg and Am) by simple correlation was closer between P-C of p.g and P-X of p.q than between both P-Xs and quite different between the P-X of p.g and that of p.n. The pattern similarities of major FAA percent abundance excluding Arg and Am were significant only between P-X and P-C of the same species. Arginine content (amole) had positive correlation (r=0.859, p=0.05) with Arg/Am among species. Ammonia content was higher than arginine in p.n. Tryptophan content was greatest in p.n among species and higher than lysine only in p.n. The ratios of TFAA to N(W/W) were in the range of 3.89~4.14 for TFAA and 3.61~3.92 for TFAA plus ammonia.

• Food Science and Preservation
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• v.14 no.6
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• pp.669-675
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• 2007

Quality characteristics of Kwamaegi (semi-dried saury) prepared by treatment of chitosan-ascorbate (CA) and vacuum drying at $40{\sim}60^{\circ}C$(VDK), and the effect of the Kwamaegi on serum lipid profiles and anti-oxidation-related enzyme activity in rats fed high fat diets were investigated. The preparation periods were $4.5{\sim}8.3$ hr in VDK, while naturally dried Kwamaegi (NDK) took 360480 hr. Total microbe contents of VDK and NDK were $0.2{\sim}0.5$ and 8.2 log CFU/g, respectively. There was no significant difference in amino-nitrogen content. Compared with NDK, the acid and peroxide value, and fishy flavor of VDK40 (dried at $40^{\circ}C$) were significantly lower, and the texture, color and overall acceptability were higher. In animal experiments, weight gain, content of LDL-cholesterol and lipid peroxide, activities of total (T) and O type (O) xanthine oxidase, and the O/T ratio (%) were significantly lower in the VDK40 diet group than in the NDK diet group. The content of HDL-cholesterol in the VDK40 diet group was higher than in the NDK diet group. These results suggest that preparing CA-treated Kwamaegi with vacuum-drying at $40^{\circ}C$ can be applied throughout the year, and may shorten preparation time and improve its microbiological safety and nutritional values.

• Korean Journal of Plant Resources
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• v.15 no.2
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• pp.135-143
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• 2002

The results of examining characteristics of mycelial growth and culture condition for determining the condition of artificially culturing Inonotus obliqua (chaga) are as follows. 1) Mycelial growth and density oft, oblique were the highest in the medium of BDA (Birch Dextrose Agar; 66.3mm/10d) followed by the order of GDA, PDA, CDA, PODA, ODA, YM, MCM, MEA (pH 7.0), CHA, and MEA (pH 4.7). 2) Optimal temperature for the mycelial growth and density of 1. obliqua were shown to be 30$^{\circ}C$, but the mycelia were dead at 40$^{\circ}C$. the mycelial growth and density of KNAC3005 strains was the highest at 30$^{\circ}C$(66.3mm/10d) followed by the order of 25, 20, 15, 35, 10, and 5$^{\circ}C$. 3) Optimal pH for the mycelial growth and density were revealed to be 6.0 (88.4mm/10d). Above or below pH 6.0, the mycelial growth and density were shown to be retarded. 4) Optimal carbon, nitrogen and organic acid sources for the spawn growth of 40 were maltose (331mg/25$m\ell$/15d), peptone (347mg/25$m\ell$/15d), and glutamic acid (357mg/25$m\ell$/15d), respectively. Optimal level of biotin was 370mg/15d and optimal C/N ratio was 40.

• The Korean Journal of Mycology
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• v.33 no.1
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• pp.22-29
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• 2005

The main objectives of this research were to study the cultural and nutritional characteristics of Tricholoma matsutake and to establish its liquid culture system. The optimum growth of T. matsutake was observed in HA and TMM agar media. Similarly highest growth was observed in PDB and TMM liquid media. The optimal temperature for the mycelial growth was $25^{\circ}C$. The most suitable carbon source was dextrin among 12 different carbon sources tested. Yeast extract and peptone were best nitrogen sources among 17 different sources tested. The optimum mineral salts were $Fe_{2}(SO_{4})_{3}{\cdot}H_{2}O$ and KCl among 9 different sources tested. Shaking culture gave higher mycelial growth compared to stationary culture. Similarly, optimum medium amount for shaking culture was 100 ml per 250 ml flask. The highest mycelial growth was obtained when $5{\sim}7$ mycelial discs were inoculated in 100 ml of medium and incubated for $8{\sim}9$ weeks, respectively. The highest proportion of mycelial growth was observed at 40 : 1 ratio of medium to inoculum volume in 8 l air-lift fermenter.

• KSBB Journal
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• v.19 no.6 s.89
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• pp.484-488
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• 2004

Fermentation studies were conducted in batch and continuous flow cell-recycle reactors with food by-products as substrates. The genus Propionibacterium acidipropionici ATCC 4965 was utilized in the production of organic acids. Good performance was achieved in the batch fermentation using hydrol as a carbon source and corn steep liquor (CSL) as nitrogen and vitamin sources. Product yields and productivity based on maximum values were 0.80 g total acids/g glucose and 0.26 g total acids/L/h, respectively, when $3\%$, (w/v) of hydrol and $2.5\%$, (w/v) of CSL were utilized. Continuous fermentation with cell-recycling system using the optimum amounts of substrates resulted in dramatic increase in cell concentration (X) and maximum productivity (P). Compared to the batch fermentation, X and P were increased by as much as 21 and 13 times, respectively, at the dilution ratio of $0.2\;hr^{-1}$, indicating that cell recycling fermentation of food by-products provides valuable means for the mass production of organic acids as well as utilizing cell mass as good nutrient resources.

• Journal of Ecology and Environment
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• v.29 no.6
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• pp.521-529
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• 2006

This study was carried out to classify all forest vegetation types in Ulleung Island, Korea using the methodology of the Z.-M. school's phytosociology, and map out the spatial distribution patterns of those vegetation types. The forest vegetation was classified into the mountain forest type (Acer okamotoanum community group) and maritime forest type (Artemisia scoparia community group). Vegetation units at the community level were divided into three categories; six communities, sixteen groups, and seven subgroups, giving a total of 22 communities. Total area for mapping was 5,544.9 ha, of which Fagus engleriana community accounted for 1,952 ha (35.2%), Hedera rhambea community ror 1,196 ha (21.6%), Camellia japonica community for 1,104 ha (19.9%), Sambucus sieboldiana var. pendula community for 612 ha (11.0%), Aster spathulifolius community for 506 ha (9.1%), and Tsuga sieboldii - Pinus parviflora community for 174 ha (3.1%). According to canonical correspondence analysis (CCA), variables such as $Mg^{2+}$, pH, $Ca^{2+}$ were positively correlated in maritime vegetation types, and variables such as total nitrogen, carbon content, C/N ratio and ration exchange capacity (CEC) were highly correlated in mountain vegetation types, respectively. The sea level and the slope direction were not showing regular trend as a factor to decide on species diversity, evenness and richness in this research area. But it seems to be affected by topography, slope degree and dominance vegetation.

• Journal of Korean Society of Forest Science
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• v.106 no.1
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• pp.10-18
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• 2017

This study was carried out to suitable plantation site from comparison and analysis of regional early growth characteristics of planted Larix kaempferi trees in harvested L. kaempferi plantations. Two-year-old bare-root seedlings of L. kaempferi were planted with the density of $3000\;seedlings\;ha^{-1}$ at four sites (Yeongju, Gimcheon, Chuncheon, and Inje). All sites were established with three plots ($400m^2$ per plot) in 2010. We analyzed soil physical and chemical properties in October 2010 and 2013. We measured root collar diameter (RCD) and height of trees in October from 2010 to 2014, and then calculated H/D ratio and stem volume. Soil pH was significantly increased and available P was significantly decreased 3 years after planting. Annual mean RCD, height, and stem volume of 5-to 7-year-old in the Chuncheon site were significantly higher than those in the other sites, however them in the Yeongju site were the lowest. It is related to the fact that total nitrogen, available phosphorus, and organic matter concentrations in the Yeongju site were relatively lower than those in the other sites. As a results of this study, we could confirm the correlation between soil properties of L. kaempferi plantations and growth of L. kaempferi trees. We could suggest values of soil properties for reforestation of L. kaempferi.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.4
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• pp.293-301
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• 2017

A Sub-kWe small-scale experimental test loop was manufactured to investigate characteristics of the supercritical carbon dioxide power cycle. A high-speed turbo-generator was also designed and manufactured. The designed rotational speed of this turbo-generator was 200,000 rpm. Because of the low expansion ratio through the turbine and low mass flowrate, the rotational speed of the turbo-generator was high. Therefore, it was difficult to select the rotating parts and design the turbine wheel, axial force balance and rotor dynamics in the lab-scale experimental test loop. Using only one channel of the nozzle, the partial admission method was adapted to reduce the rotational speed of the rotor. This was the world's first approach to the supercritical carbon dioxide turbo-generator. A cold-run test using nitrogen gas under an atmospheric condition was conducted to observe the effect of the partial admission nozzle on the rotor dynamics. The vibration level of the rotor was obtained using a gap sensor, and the results showed that the effect of the partial admission nozzle on the rotor dynamics was allowable.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.9
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• pp.597-603
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• 2012

To investigate the effects of weir construction on sediment characteristics of river bed, we conducted sediments sampling on the 9 locations near the weir, Kangchun, Yuju and Ipo in Namhan-River. Physical and chemical characteristics of sediments were analyzed by measuring particle size distribution, water content, Ignition loss, COD (Chemical Oxyzen Demand), TOC (Total Organic Carbon), TP (Total Phosphorus), SRP (Soluble Reactive Phosphorus) and TN (Total Nitrogen). Particle classification of all three weir sediments showed sandy loam that was caused by the river bed dredging. Due to the presence of weir, Ignition loss, COD, TOC, TP, SRP and TN showed similar trend such as the concentrations of upward weir had higher than those of downward weir. For the case of SRP concentration and C/N ratio, however, there is not much difference in the sediment characteristics compared to the those of sediments before weir construction. Therefore, It can be predicted that there are little effects of weir construction on sediment characteristics. However, weir construction could influence water quality of the river by controlling the transport and the accumulation of suspended materials from rainfall. Therefore, more intensive monitoring is required to examine the magnitude and patterns of sediment accumulation which could influence overlying water quality.