• Microbiology and Biotechnology Letters
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• v.3 no.1
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• pp.7-15
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• 1975

The possibilities of utilizing acid-hydrolyzate of "Sliced and dried sweet potatoes" as a carbon source for the microbial production of L-Glutamic Acid(L-GA) with Micrococcus glutamicus were investigated and the results showed as follows： 1) The highest hydrolysis rate, 74.6% of the reducing sugar based on the weight of dry matter, was obtained when the sweet potatoes were hydrolyzed with 0.8% of HCI at 2.0kg/$cm^2$ for 30 minutes. The most favorable hydrolyzate for the growth of the cells, however, was found to be the one obtained by treating the sweet potatoes with 0.5% HCI at 2. 0kg/$cm^2$ for 10 minutes. Reducing sugar content of the hydrolyzate was 10% as glucose. 2) Biotin content of the hydrolyzate was 25$\mug$/1 and it was proved to be excess in amount for the L-GA production. 3) The effects of addition of antibiotics, alcohols and fatty acid esters on the L-GA production were tested in the biotin excess medium. The production of L-GA was most increased to 32.5g/l with the addition of 10 I. U. of penicillin per ml. to the culture medium at 4 hours after inoculation. But the addition of alcohols, especially fatty acid esters, showed no significant effects. 4) Among the organic nutrients tested. " Gluten acid hydrolyzate" greatly enhanced the production of L-GA adding it＇s concentration of 1.0% to the medium. 5) The maximum production of L-GA resulted in 35g/1 when the cells were grown for 48 hours in the hydrolyzate medium supplemented with 1.0% of "Gluten acid hydrolyfate" and with 10 I. U. of penicillin per ml added at 4 hours after cultivation.

• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.705-713
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• 2011

In this paper, we introduce two techniques for resolving integer ambiguities between reference stations, which is one of the most important processes in Network RTK correction generation process. Each techniques uses Hatch filter and combination of L1/L2 measurements and we used simulation data and real data to evaluate performance of the techniques. For evaluating performance of each technique, we compared corrections generated from user site and Network RTK. As a result, Network RTK with the technique which uses Hatch filter improves user performance much more than single baseline RTK does. Residual of user is smaller than a half size of wavelength so it does not affect user integer ambiguity resolution, however, it contains significant bias error. On the other hand, when we used the technique which uses combination of L1/L2 measurements, residual error of user is largely reduced compared to the technique using Hatch filter.

• Microbiology and Biotechnology Letters
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• v.43 no.2
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• pp.164-168
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• 2015

Citric acid is produced via submerged fermentation using yeasts. Among eight different strains of yeast, Candida zeylanoides was chosen as the strain for producing citric acid and optimized for various C/N ratios and effects of phosphate or Fe²⁺ ions in a clean carbon source medium (glucose: fructose, 1:1). The yield of citric acid was maximized at a C/N ratio of 40/1, a phosphate addition of 1.0 g/l, and an Fe²⁺ ion concentration of less than 50 mg/l, yielding up to 91 g/L in the broth with 18.5 g/l of isocitric acid in a six-day fermentation period using a pre-treated molasses medium. The yield of batch culture was 0.51 (Y_p/s, g/g) in a 5 L-Jar fermenter.

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.168-173
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• 2008

This study was conducted to determine biological characteristics of Acorus calamus L. angustatus by using aqueous, ethanol and methanol extracts from the leaves and the rhizomes of Acorus calamus L. angustatus plants. The highest total phenol contents were found in the extracts from the leaves of Acorus calamus L. angustatus ($68.4mg{\cdot}L^{-1}$) followed by rhizome ($49.3mg{\cdot}L^{-1}$). At $1,000mg{\cdot}L^{-1}$ the free radical scavenging activity of 1, 1-Diphenyl-2-picrylhydrazyl showed the highest activity in the extracts of the leaves and the rhizomes by 86.3% and 86.1%, respectively. Total flavonoid contents at $2,000mg{\cdot}L^{-1}$ extracts showed the greatest amount in the aqueous leaf extracts ($61.1mg{\cdot}L^{-1}$), and the ethanol rhizome extracts ($15.4mg{\cdot}L^{-1}$). Nitrite radical scavenging activity at $2,000mg{\cdot}L^{-1}$ was highest in the methanol extracts from leaves and rhizomes by 75.7% and 77.9%, respectively. Mushroom tyrosinase inhibition activity of leaves and rhizome from the Acorus calamus L. angustatus was very low, showing less than 1.3% regardless of the extract solvent, plant part, and concentration. These results indicated that methanol extracts from leaves exhibited higher biological activities than other extracts from rhizomes.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.2017-2023
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• 2000

A dynamic model was applied to compare the environmental parameters and effluent characteristics of refinery wastewater in activated sludge treatment. The measured DO, pH, MLSS, and COD values were compared with the simulated their results in the activated sludge reactor. As results of simulation. good agreements between the measured and simulated results were investigated. The simulated and measured effluent COD were 19.0~19.4mg/L and 23.1mg/L. respectively. The simulated and measured DO were 1.9~2.4mg/L and 2.2mg/L. respectively.

• Journal of the Korean Chemical Society
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• v.34 no.3
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• pp.260-266
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• 1990

The electrochemical behavior of N-methyl-2-amino-l-cyclopentene-l-dithiocarboxylic acid $(N-CH_3 acdc) and 2-amino-l-cyclopentene-l-dithiomethyl ester (S-CH_3 acdc) in DMF have been investigated by the use of polarography, cyclic voltammetry and coulometry. The dimer of N-CH_3 acdc is further oxidized at +0.98 V via 2-electron process to produce free sulfur atom and cyclization product. The ring formation between two dithio group occurs along with the elimination of one sulfur atom. The elimination of sulfur atom occurs via two electron oxidation process at + 0.98 V vs. Ag/AgCl electrode. However, the cyclization does not occur in the S-CH_3$ acdc.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.361-366
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• 2000

To study the abundances and species composition of microzooplankton during summer, microzooplankton were sampled fortnightly from 22 May to 3 August in Kwangyang Bay, Korea, The dominant species were Tintinnopsis spp. and Coaonellopsis sp. of tintinnids, and eggs and nauplii of copepods, They occupied $83.8{\%}$ of the total microzooplankton. The abundance of microzooplankton on 22 May was $374.6 ind./l$. It increased to 1,276.0 ind./l and 1,234.9 ind./l in June, and then reduced to $528.2{\~}609.8 ind./l$ in July and August. The abundances and species composition of microzooplankton were affected by the predation of fish larvae.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.19-24
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• 2001

A solvent sublation has been studied for the determination of trace Au(III), Pt(IV) and Pd(II) in waste water with their complexes of 2-mercaptobenzothiazole (MBT). Experimental conditions such as the concentration of HCl, the amount of MBT as a ligand, the type and amount of surfactants, bubbling rate and time, and the type of organic solvent were optimized for the solvent sublation, i.e., 25.0 mL of 2.0 M HCl solution and 30mL of 0.4%(w/v) MBT ethanolic solution were added to a 1.0 L sample to form stable complexes. The addition of 4.0 mL of 1 ${\times}$$10^{-3}$ M CTAB (cetyltrimehtylammonium bromide) solution was needed for the effective flotation accomplished by bubbling nitrogen gas at the rate of 40.0 mL/min for 35 minutes. As a solvent, 20.0 mL of MIBK (methylisobuthylketone) was used to extract the floated complexes. The procedure was applied to three kinds of waste waters. Au(III) was determined as 0.68 ng/mL and 0.98 ng/mL respectively for final washed water of two plating industries in Banwol. Pd(II) and Pt(IV) were not detected in any of the three samples. The recovery, which was obtained with analyte-spiked samples, were 95-120%.

• Korean Journal of Ecology and Environment
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• v.38 no.4 s.114
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• pp.461-474
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• 2005

Physicochemical parameters, plankton community structure, and sediment were surveyed from 1988 to 2002, at two months interval, in a eutrophic coastal lagoon (Lake Songji, Korea). The lake basin is separated from the sea by a narrow sand dune, and a shallow sill divides the lake basin into two sub-basins. The stable stratifications and chemoclines are maintained all through the year at 1-2 m depth. DO was often very low (<1 $mgO_2\;{\cdot}\;L^{-1}$) in the monimolimnion. Secchi disc transparency was in the range of 0.5-2.7 m. TP, TN, and Chl. a concentration in the mixolimnion were 0.015-0.396 $mgP\;{\cdot}\;L^{-1}$), 0.223-3.521 $mgN\;{\cdot}\;L^{-1}$, and 0.5-129.8 mg ${\cdot}\;m^{-3}$, respectively. TSI was in the eutrophic range of 54 to 62. Sediment was composed of silt and coarse silt. COD, TP, and TN content of the sediment were 51.4-116.9 $mgO_2\;{\cdot}\;gdw^{-1}$, 0.04-1.46 $mgP\;{\cdot}\;gdw^{-1}$ and, 0.12-1.03 $mgN\;{\cdot}\;gdw^{-1}$, respectively. The 49 phytoplankton species were identified. The maximum phytoplankton abundance obscured the lake in September 2001 (max. density: 23,350 cells ${\cdot}\;mL^{-1}$. The Chlorophyte Schroederia judayi was dominant species in summer (max. density: 20,417 cells ${\cdot}\;mL^{-1}$). The lake showed unique limnological features of a brackish lagoon in respect to biological community, chemical characteristics, and physical phenomena.

• The Korean Journal of Malacology
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• v.28 no.4
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• pp.305-312
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• 2012

Manila clam, Ruditapes philippinarum (SL; $32.74{\pm}2.18mm$, TW; $8.29{\pm}1.41g$, N; 450) were exposed to various concentrations of naphthalene for 20 weeks. Exposure concentrations of naphthalene established control, solvent control (ethanol), 30, 60, 90 and $120{\mu}g$ Nap $L^{-1}$ following results of 96h acute exposure. After exposure during 20 weeks, survival rate of the manila clam was lowed in 60, 90 and $120{\mu}g$ Nap $L^{-1}$ exposure group compared control group. Also, sex ratio of male was higher in $60{\mu}g$ Nap $L^{-1}$ exposure group (${\chi}^2=5.492$, P < 0.05) but lowed $90{\mu}g$ Nap $L^{-1}$ exposure group (${\chi}^2=4.214$, P < 0.05) and $120{\mu}g$ Nap $L^{-1}$ exposure group (${\chi}^2=30.118$, P < 0.05). Gonad development was delayed in female (> $60{\mu}g$ Nap $L^{-1}$) and male (> $30{\mu}g$ Nap $L^{-1}$). Intersex was 16.28% in female, 1.68% in male. In this result, naphthalene caused survival decrease, imbalance of sex ratio, delay of gonad development of the manila clam. Also, chronic exposure to naphthalene suggested abnormal effects in reproduction of the manila clam.