• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.556-557
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• 2001

This study was performed to improve the efficency of production of biosudactant which were produced by newly screened MNNGCN-Methyl-N-Nitro- Nitrosoguanidine) mutagenized P. aeruginosa EMS1. A culture grown exponentially for $30^{\circ}C$ in trypic soy brotb is adjusted to pH. MNNG is added and incubated in water bath shaker at about 250 ${\sim}$300rpm. After 20 min, is dilutecl into colded trypic soy broth and centrifugation. The cell pellet is resuspended in 50$m{\ell}$ of trypic soy broth. Cultures are grown at $30^{\circ}C$ overnight. cetyltrimethylammonium bromide-metbylene blue agar plate selected dark blue halo colony. Peanut oil, Castor oil, Olive oil, and so on were compared as carbon source of surface tension and emulsifying activity.

• Journal of Nutrition and Health
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• v.29 no.10
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• pp.1096-1104
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• 1996

This study was performed to evaluate the effect of sodium cholride supplementation on bone metabolism in female rats consuming a low calcium diet. Twenty five female rats were divided into three dietary groups (control Na : 0.1038%, 1% Na : 1.036%, 2% Na : 2.072%). All experimental diets contained 0.27% Ca and were fed to rats with deionized water for 7 weeks. Bone mineral density(BMD) and bone mineral content(BMC) of total body, spine and femur were measured using energy x-ray absorptiometry(DEXA) by small animal software. Then Ca efficiency was calculated from BMD and BMC. Serum Ca, P, Na and urine Ca, P, Na were determined. Urinary pyridinoline, serum ALP were measured to monitor bone resorption. Following 7 weeks, sodium cholride supplemented groups had higher urinary Ca excreteion, urinary pyridinoline, crosslinks value and serum ALP. There was no significant difference in case of serum Ca among all groups. Sodium chloride supplemnted groups had lower Ca effciency of total, spine and femur BMD and BMC than that of control group. In conclusion high salt intake not only increases urinary Ca excretion as urinary Na excretion does but also increase bone resorption and decrease Ca efficiency of each bone. It is been suggested that high salt intake may be harmful for bone maintenance. Therfore, the decrease of salt intake to the level of recommendation would be desirable.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.559-564
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• 1992

To increase the efficency of utilizing cellulosic biomass, a potent xylanase producing bacteria was isolated and identified as Bacillus sp. N-25. Extracellular xylanase from Bacillus sp. N-25 was partially purified by ammonium sulfate precipitation, DEAE-Sephadex A-25 and Sephadex G-IOO column chromatographies. The xylanase was single fraction on chromatography and was true xylanase without cellulase activity. The enzyme was stable at pH 6-8 and 80% activity was remained at $50^{\circ}C$ for 30 min, but was inhibited by $Hg^{2+}$, $Ag^{2+}$, and $Mn^{2+}$. From the fact that the major end product was xylose, we suggested that the enzyme is an exo-xylanase which may be a prime candidate for industrial use.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.549-552
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• 2008

We have developed a novel bipolar host material with both electron and hole transporting characteristics. Since CGH(Cheil Green Host) has some electron transporting characteristics, it shows increased luminance efficiency in device including TCTA and without HBL(hole blocking layer:BAlq). Maximum power efficency of CGH was 27.4lm/W at the device structure ITO/DNTPD(60)/NPB(20)/TCTA(10)/EML(30)/Alq3(20)/LIF(1)/Al. We measured device performance again without HBL. The result of CGH showing 26.0lm/W is outstanding compared to that of CBP showing 19.1lm/W without holeblocking layer. We also measured lifetime and found to be 205hr at 3000nit, that is significant result compared to the life time of CBP device showing 82hr. CGH shows high device performance with holeblocking layer. Moreover, it shows better device performance and life time than those of CBP without holeblocking.

• The Journal of the Acoustical Society of Korea
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• v.16 no.5
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• pp.83-91
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• 1997

A reactor vibration monitoring has been performed using neutron noise obtained from excore detectors for the safety operation, Traditionally, the spectral estimator based on Fourier analysis has been widely used in the noise analysis of the reactor system. If the bias is too severe, the resolution would not be adequate for a given application. One major motivation for the current interests in the parametric approach to spectral estimation is the apparent higher resolution achievable with these modern techniques. In considering an unbias, a consistency, an efficency, and a minimum lower bound of the statictic estimation, an AR model is appropriate for noise spectral estimation with sharp peaks but not deep valley. In order to select an appropriate model order, the lag value of autocorrleaton function is applied. Burg method to trace the vibration mode of RPV internal is the most sucuessful.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.267-268
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• 2005

In this paper, the inorganic-organic thin film encapsulation layer was newly adopted to protect the organic layer from moisture and oxygen. Using the electron beam, Sputter and Spin-Coater system, the various kinds of inorganic and organic thin-films were deposited onto the Ethylene Terephthalate(PET) and their interface properties between organic and inorganic layer were investigated. In this investigation, the SiON and Polyimide(PI) layer showed the most suitable properties. Under these conditions, the WVTR(water vapour transition rate) for PET can be reduced from level of 0.57 g/$m^2$/day (bare subtrate) to $1{\times}10^{-5}$ /$m^2$/day after application of a SiON and Polyimide layer. These results indicates that the SiON/PI/SiON/PI/PET barrier coatings have high potential for flexible organic light-emitting diode(OLED) applications.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.5
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• pp.431-440
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• 2017

The small-scale sewage treatement system with $A^2/O$ process was applied to evaluate applicability for Mongolian sewage, It was designed to have 10 m3/d flowrate and installed in Ulaanbaatar, Mongolia. During over 6month operation BOD, COD, TN, TP removal efficiency were measured and operation condition was optimized. In addition, MLSS concentration its internal circulation rate and DO were adjusted properly. BOD, COD showed average 88 perecent of removal and TN and TP achieved 81 percent and 88 percent removal efficency, respectively. Maxium influent concentration of BOD, COD, TN and TP was 214 mg/L, 300 mg/L, 24.3 mg/L and 5 mg/L respectively, which were decreased to 4.1 mg/L, 5.6 mg/L, 1.3 mg/L and 0.15 mg/L by the test system. This study show possibility tham small-scale sewage treatment system could be a useful system for scattered sewage wastewater treatment.

• Journal of Korea Foresty Energy
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• v.2 no.2
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• pp.1-12
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• 1982

To study tile comparison of aboveground biomass of Pinus rigida Mill. of 18-year-old, plantations located in Whaseong, Yuseong and Wanju district were selected. Ten sample trees in each district selected taking account of DBH distribution were felled carefully to minimize loss of branches and stem analysed by 1m lag segment sectioned from base . The tree height and DBH were measured for sample trees in total growing within $200m^2$ experimental plot. The diagram of oven-dry weight distribution of stem, branch and needle for each 1m segment was constructed. The logarithmic regression equations between dry weight of each component and the two variables, $DBH^2$ and tree height, combined term were presented. The standing crops in the sample stand was estimated to be as much as 23.88, 54.09 and 42.68 tons of dry matter, above ground , per ha in Whaseong, Yuseong anf Wanju district respectively. Annual net production was estimated at 253,657 and 3.65 tons per ha per year respectively. The net assimilation rate was 1.65,1.95 and 1.81 kg/kg/yr in Whaseong, Yuseong and Wanju district respectively. The efficency of leaf to produce stem was 0.99, 1.12 and 1.30 kg/kg/yr respectively.

• Journal of the Korean Chemical Society
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• v.43 no.4
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• pp.430-437
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• 1999

The determination of total chlorine residuals in drinking water by flow injection analysis(FIA) with iodometric UV detection was investigated. The pH of the acid stream, the concentration of the iodide ion,the length of the mixing and reaction coils, the injection sample size, and flowrate were optimized as parameters for determining total chlorine residuals by FIA method. lodide was selectively oxidized to iodine by hypochlorite at pH 8.3 Ethylenediamine as masking agent for masking interference ions from the sample was given the best efficency. Calibration curve presented linear range of 0.03-3 mg/L for hypochlorite ion with a correlation coefficient of 0.999 or better. The detection limit was found to be 0.007 mg/L for hypochlorite ion. Under these analytical conditions, total chlorine residuals in several tap water sampled in the city of Jeonju were analyzed.

• Journal of the Korean Society of Safety
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• v.17 no.4
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• pp.25-30
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• 2002

This paper demonstrates the effects of dust electrical resistivity on electrostatic precipitability. The effects of gas temperature, velocity and humidity on the collection efficency were considered by used of coal fly ashes from fluidized bed combustion boiler. The experiments for collection efficiency were carried out in the pilot plant. The ashes which have non-spherical geometry and high electrical resistivity were used. Electrical resistivity is an important property for the collection efficiency in the electrostatic precipitators. Fly ash resistivity as a function of temperature up $350{\circ}C$ and water concentration(up to 15%) has been experimentally investigated using the resistivity test equipment consisted of the movable electrode, dust cup, and furnace. As the resistivity of fly ash in the operating temperature($150{\circ}C$) of an electrostatic precipitator was measured higher than $1010{\Omega}{\cdot}$cm, flue gas conditioning in the electrostatic precipitator to reduce the resistivity of fly ash is required.