• Economic and Environmental Geology
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• v.24 no.3
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• pp.233-244
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• 1991

A biotite that substantially altered to chlorite and vermiculite in hornblende gneiss from Cheonyang, Korea, has been investigated with electron microprobe analysis. The data show the general variational trends of Ti and K-leaching with increased weathering. However, the chloritization is characterized by Si- conservative reaction and relatively dramatic increase of Al-for-(Fe+Mg) octahedral substitution, whereas the vermiculitization is characterized by total Mg-conservative and Ca-enriching exchange reaction. In the initiating stage the vermiculitization proceeded in a continuous decrease of the Al-for-Si tetrahedral substitution and an increase of the Al-for-(Fe+Mg) octahedral substitution, supporting the currently accepted weathering process. But it differs in the late stage, in which AI(IV) and Fe increase significantly. Recalculations of the structural formular for vermiculite on the basis of several assumptions indicate that the oxidation of Fe is necessary for vermiculite to form the reasonable strutural formular. The relative timing of the oxidation of Fe probably occurs in the late stage, supported by the substantial increase of the Al-for-Si tetrahedral substitution.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.12
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• pp.1063-1069
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• 2012

In present paper, we used magnesium alloy having a lower density and higher electrical conductivity for bipolar plate to reduce the weight of PEM fuel cell. The silver was coated to prevent corrosion and form passivation film on the metal surface with sputtering. In acid proof evaluation for setting optimal coating conditions, the homogeneity of coating thickness was improved by coating with the thickness of 3 ${\mu}m$ which not indicated any micro cracks and the temperature $180^{\circ}C$. The performance test and evaluation based on the clamping pressure and channel depth to determine the configuration of bipolar plate for assembling single cell was implemented. And then we assembled single cell with this bipolar plate and implemented the performance test to ensure and compare the current-voltage performance followed as several factors such as coating or non-coating, the change of clamping pressure, the change of channel depth, etc. As these results, the maximum power density of single cell with the coated bipolar plate was 192 $mW/cm^2$ and it was confirmed that the power density per unit mass was better than existing metal bipolar plate.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.3
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• pp.247-260
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• 2010

The developement of a HLW disposal canister is under way in KAERI using Cold Spray Coating technique. To estimate corrosion behavior of a cold sprayed copper, a creivice corrosion test was conducted at Southwest Research Institute(SWRI) in the United State. For the measurement of repassivation potential needed for crevice corrosion, three methods such as (1) ASTM G61-86 : Cyclic Potentiodynamic Polarization Measurements, (2) Potentiodynamic Polarization plus intermediate Potentiostatic Hold method, and (3) ASTM G192-08 (THE method) : Potentiodynamic- Galvanostatic-Potentiostatic Method, were introduced in this report. In the crevice corrosion test, the occurrence of corrosion at crevice area was optically determined and the repassivation potentials were checked for three kind of copper specimens in a simulated KURT underground water, using a crevice former dictated in ASTM G61-86. The applied electrochemical test techniques were cyclic polarization, potentiostatic polarization, and electrochemical impedance spectroscopy. As a result of crevice corrosion tests, every copper specimens including cold sprayed one did not show any corrosion figure on crevice areas. And the open-cell voltage, at which corrosion reaction initiates, was influenced by the purity of copper, but not their manufacturing method in this experiment. Therefore, it was convinced that there is no crevice corrosion for the cold sprayed copper in KURT underground environment.

• Applied Biological Chemistry
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• v.38 no.3
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• pp.191-195
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• 1995

Production of a high viscosity exoploysaccharide, methylan, by Methylobacterium organophilum from methanol was carried out in fed-batch cultures and the rheological properties of methylan fermentation broth were studied. Bacterial biomass showed little influence on viscosity, but the accumulation of methylan caused the increase of viscosity. With proceeding fermention, the viscosity at the same concentration of methylan was significantly increased and methylan solution showed slightly higher pseudoplasticity. The composition changes of methylan were investigated at various fermentation times. Contents of total sugar, reducing sugar and methylan were decreased but contents of acids(pyruvic acid, uronic acid and acetic acid) were increased with the culture time. It was considered that the increased content of acids resulted in the increase of the hyrodynamic domain in the solution due to charge repulsion. Consequently, the solution viscosity increased in propotion to the acids contents of methylan. Cell growth and methylan production were severely decreased by the limitation of dissolved oxygen. However, the cellular activity for methylan production was almost constant regardless of the level of dissolved oxygen. As a result, the high speed of agitation increased the methylan production, the specific production rate of methylan, and the methylan yield of the cell.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.187-195
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• 1985

Electrophoretic studies of protein extracts from carrot calluses suspension-cultured on the media containing kinetin, BA, IAA, NAA or $GA_3$ at the levels of $10^{-6},\;10^{-5},\;10^{-4}M$, respectively, were performed to identify polypeptides and proteins regulated by auxin, cytokinin or GA. Fifteen bands of polypeptide(s) were observed in the callus cultured in the control medium devoid of growth regulators, and their molecular weights were $18._4,\;20._2,\;20._0,\;34._9,\;35._7,\;37._4,\;40._3,\;42._2,\;44._1,\;44._4,\;49._3,\;55._0,\;56._6,\;58._1,\;and\;59._9\;KD$, respectively. The synthesis of polypeptide appeared to be promoted in two bands by kinetin, in six bands by BA, in one band by IAA, in two bands by NAA, and in four bands by $GA_3$, while inhibited in five bands by kinetin, in three bands by BA, in four bands by IAA, in three bands by NAA and in three bands by $GA_3$. The polypeptides of $40._3\;KD\;42._2\;KD$ seemed to be regulated by cytokinins, and those of $44._1\;KD,37._4\;KD,\;and\;56._6\;KD$ by auxins. The proteins of three bands with relative mobilities of 0.56, 0.84, and 0.92, respectively, increased in the calluses cultured on the media containing kinetin, IAA, $GA_3$, NAA or BA, compared to the control, but it was difficult to identify the proteins specific for each growth regulator.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.3
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• pp.9-16
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• 2008

We centrally study effect of very high voltage 345kV T/L which is set up at residential area (Yangyang~Donghae in Gangwon-do) to broadcasting radio wave and human body. First, to compare predicted result of radio wave disturbance, we set 7 area 13 point and divide broadcasting quality, electric and magnetic fields in T/L process. Result of estimation, we confirm that when receiving broadcasting radio wave, broadcasting quality's difference is generated by topographic property of near receiving point. also through result of electric fields and broadcasting quality and their comparison, we judge that high voltage T/L is barely affect receive of broadcasting radio wave. To judge effect of magnetic fields to human body, we analyze magnetic fields in variable area and condition. as a result, magnetic fields of every area has 1.8mG(WHO international standard amount is 833mG). So It is proved that magnetic fields of 345kV Yangyang~Donghae area has slight, tiny effect to human body.

• Journal of Navigation and Port Research
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• v.37 no.6
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• pp.575-580
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• 2013

The IMU(Inertial Measurement Unit) which is the expensive equipment has been used as a special limited area, usually in measurement of posture of applying to the areas of ship, submarine, aircraft and military equipment application. However, in the current situation, MEMS AHRS technology can replace the high-priced IMU in MEMS AHRS selected application field. In this paper, wireless hull motion measurement system was suggested for measuring key elements of ship's movement such as rolling, pitching and yawing using gyro, acceleration and magnetic sensors of AHRS. In order to reduce the error such as instantaneous acceleration, effects and vibration of geomagnetic, we have adopted the sensors equipped with Kalman filtering. The Wireless hull motion measurement system using AHRS sensors was tested in actual ship and it could easily be applied in limited installation circumstances of the ship. In the future, this system can be useful in the navigation safety and marine accident analysis by using with ship equipment such as INS or VDR in the maritime.

• Korean Security Journal
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• no.61
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• pp.9-38
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• 2019

As the scales & density of the Korean national infrastructures have been increased, they will be identified as rich and attractive potential targets for intensified North Korea's attack in the rear region and terrorism attack. In addition, due to changes in security environment such as drone threats and lack of security forces under the 52-hour workweek law, I think that it is the proper time point to reevaluate the effectiveness and appropriateness of the current physical protection system and its shift to a new system. In this study, the direction and improvement of the perimeter physical protection systems of the national infrastructures are to be studied from the viewpoints of its concepts of operations and design methodology, focusing on the nuclear power plant. The reason why we focus on nuclear power plants is because they cause wide-range and long-term damages caused by radioactive materials disperal and pollution, along with short-term damage caused by the interruption of electricity generation in the event of damage to nuclear power plants. With the aim of extracting improvement directions, as we will comprehensively review domestic research trends and domestic·overseas related laws, and consider Korea's specificity, we try to reframe the concept of operation - systematization, mobilization and flexibility -, and establish criteria on system change. In order to improve the technical performance of the new perimeter physical protection system, we study on high-fidelity·multi-methodology based integrated design methodology, breaking from individual silo-type design methods, and I suggest improvement of government procurement, its expansion to export business and other national infrastructure.

• Korean Journal of Pharmacognosy
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• v.43 no.1
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• pp.39-45
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• 2012

Cirsium japonicum var. ussuriense has long been used in herbal medicine for the treatment of arthritis, dyspepsia, and bleeding in Korea. In the present study, we investigated anti-inflammatory effects of C. japonicum var. ussuriense against lipopolysaccharide(LPS)-induced activation in RAW264.7 cells by the expression of heme oxygenase (HO)-1. The 70% EtOH extract of the aerial parts of C. japonicum var. ussuriense (CJE), showed the potent anti-inflammatory effects on LPS-induced inflammation in RAW264.7 cells. The anti-inflammatory effect of CJE was demonstrated by the suppression of pro-inflammatory mediators, including pro-inflammatory enzymes (inducible nitric oxide synthase and cyclooxygenase-2). Furthermore CJE induced HO-1 expression through nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) and increased HO activity in RAW264.7 macrophages. The effects of CJE on LPS-induced NO and $PGE_2$ productions were partially reversed by an HO-1 inhibitor, tin protoporphyrin (SnPP). Therefore, it is suggested that CJE-induced HO-1 expression plays a role of the resulting anti-inflammatory effects in macrophages. These results suggest that CJE may be a promising candidate for the treatment of inflammatory diseases.

• Korean Journal of Poultry Science
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• v.25 no.4
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• pp.177-183
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• 1998

A feeding trial was conducted to investigate the performance of various Korean Native Chickens (KNC) for 64 weeks. Eight hundreds and ten KNC one-day birds were arranged to three strains, Dark Brown(D), Light Brown(L) and Black(B). Each strain had three replicates of 90 birds a replicate. Birds fed same diet with Korean standard feeding. Data were obtained growing performance to 20 week of age and laying performance from twenty one to sixty four week. During the growing stage from hatch to 20 week of age, there were not significant difference to three strains on viability, body weight and feed intake. L strain tended to be earlier 50％ egg production day than that of other strains, but was not significantly different. Egg production of L strain was the highest of strains. It showed significantly higher egg production compared to that of D strain(P<0.05), but was not statistically different from that of B strain. Laying peak period was between 28 to 32 week of age in all strains, Egg weight was heavier in D strain(P<0.05). Feed intake was the same as 105g, and feed conversion improved in L strain(P<0.05). There were not difference on interior egg and eggshell quality by strains although eggshell thickness improved slightly in D strain. Fertility of D strain was the highest compared to others(P<0.05) regardless laying stages. Hatchability was not influenced by strains at 39 weeks old, but was significantly higher in B strain at 62 week of age(P< 0.05). The results of this experiment indicated that KNC 3 strains were not effect on egg production, feed intake and feed conversion ratio.