• Title/Summary/Keyword: 안정성도

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정지궤도 통신해양기상위성의 기상분야 요구사항에 관하여

  • Ahn, Myung-Hwan;Kim, Kum-Lan
    • Atmosphere
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    • v.12 no.4
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    • pp.20-42
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    • 2002
  • Based on the "Mid to Long Term Plan for Space Development", a project to launch COMeS (Communication, Oceanography, and Meteorological Satellite) into the geostationary orbit is undergoing. Accordingly, KMA (Korea Meteorological Administration) has defined the meteorological missions and prepared the user requirements to fulfill the missions. To make a realistic user requirements, we prepared a first draft based on the ideal meteorological products derivable from a geostationary platform and sent the RFI (request for information) to the sensor manufacturers. Based on the responses to the RFI and other considerations, we revised the user requirement to be a realistic plan for the 2008 launch of the satellite. This manuscript introduces the revised user requirements briefly. The major mission defined in the revised user requirement is the augmentation of the detection and prediction ability of the severe weather phenomena, especially around the Korean Peninsula. The required payload is an enhanced Imager, which includes the major observation channels of the current geostationary sounder. To derive the required meteorological products from the Imager, at least 12 channels are required with the optimum of 16 channels. The minimum 12 channels are 6 wavelength bands used for current geostationary satellite, and additional channels in two visible bands, a near infrared band, two water vapor bands and one ozone absorption band. From these enhanced channel observation, we are going to derive and utilize the information of water vapor, stability index, wind field, and analysis of special weather phenomena such as the yellow sand event in addition to the standard derived products from the current geostationary Imager data. For a better temporal coverage, the Imager is required to acquire the full disk data within 15 minutes and to have the rapid scan mode for the limited area coverage. The required thresholds of spatial resolutions are 1 km and 2 km for visible and infrared channels, respectively, while the target resolutions are 0.5 km and 1 km.

Effect of Hypoxia-Ischemia on Striatal Monoamine Metabolism in Neonatal Rat Brains (저산소-허혈 손상이 신생 흰쥐의 뇌 선조체(Striatum) Monoamine 대사에 미치는 영향)

  • Jee, Youn Hee;Kim, Hyung Gun;Park, Woo Sung;Chang, Young Pyo
    • Clinical and Experimental Pediatrics
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    • v.46 no.8
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    • pp.789-794
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    • 2003
  • Purpose : We intended to evaluate the effect of hypoxia-ischemia on extracellular striatal monoamine metabolism in neonatal rat brains by in vivo microdialysis. Methods : The right common carotid arteries of five or six-day old rats were surgically ligated, and the probes for microdialysis were inserted into the right striatum with stereotaxic instrument. After stabilization for two hours, artificial cerebrospinal fluid was infused via the probe for microdialysis and samples were collected during hypoxia-ischemia and recovery periods at 20 minute intervals. The concentrations of DA(dopamine), DOPAC(3,4-di-hydroxyphenyl acetic acid), HVA(homovanillic acid), NE(norepinephrine), and 5-HIAA(5-hydroxy indole-acetic acid) were measured by HPLC(high performance liquid chromatography) and the changes were analysed. Results : The striatal levels of dopamine metabolites such as DOPAC and HVA, were significantly decreased during hypoxia-ischemia, and increased to their basal level during reoxygenation(P<0.05). Dopamine mostly increased during hypoxia but statistically not significant(P>0.05). DOPAC showed the most remarkable decrease($23.0{\pm}4.2%$, P<0.05), during hypoxia-ischemia and increase to the basal levels during reoxygenation($120.8{\pm}54.9%$, P<0.05), and HVA showed the same pattern of changes as those of DOPAC during hypoxia-ischemia($35.3{\pm}7.6%$ of basal level, P<0.05) and reoxygenation ($105.8{\pm}32.3%$). However, the level of NE did not show significant changes during hypoxia-ischemia and reoxygenation. The levels of 5-HIAA decreased($74.9{\pm}3.1%$) and increased($118.1{\pm}7.8%$) during hypoxia-ischemia and reoxygenation, respectively(P<0.005). Conclusion : Hypoxia-ischemia had a significant influence on the metabolism of striatal monoamine in neonatal rat brains. These findings suggest that monoamine, especially dopamine, and its metabolites could have a significant role in the pathogenesis of hypoxic-ischemic injury of neonatal rat brains.

The Latest Progress on the Development of Technologies for $CO_2$ Storage in Marine Geological Structure and its Application in Republic of Korea (해저 지질구조내 $CO_2$ 저장기술의 연구개발 동향 및 향후 국내 실용화 방안)

  • Kang, Seong-Gil;Huh, Cheol
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.11 no.1
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    • pp.24-34
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    • 2008
  • To mitigate the climate change and global warming, various technologies have been internationally proposed for reducing greenhouse gas emissions. Especially, in recent, carbon dioxide capture and storage (CCS) technology is regarded as one of the most promising emission reduction options that $CO_2$ be captured from major point sources (eg., power plant) and transported for storage into the marine geological structure such as deep sea saline aquifer. The purpose of this paper is to review the latest progress on the development of technologies for $CO_2$ storage in marine geological structure and its perspective in republic of Korea. To develop the technologies for $CO_2$ storage in marine geological structure, we carried out relevant R&D project, which cover the initial survey of potentially suitable marine geological structure fur $CO_2$ storage site and monitoring of the stored $CO_2$ behavior, basic design for $CO_2$ transport and storage process including onshore/offshore plant and assessment of potential environmental risk related to $CO_2$ storage in geological structure in republic of Korea. By using the results of the present researches, we can contribute to understanding not only how commercial scale (about 1 $MtCO_2$) deployment of $CO_2$ storage in the marine geological structure of East Sea, Korea, is realized but also how more reliable and safe CCS is achieved. The present study also suggests that it is possible to reduce environmental cost (about 2 trillion Won per year) with developed technology for $CO_2$ storage in marine geological structure until 2050.

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Changes in Meat Quality Characteristics on Refrigerated Pork Loin Fed with Supplemental Bamboo Vinegar (죽초액을 급여한 돼지고기의 저장 중 육질특성 변화)

  • Kook, K.;Kim, K. H.
    • Journal of Animal Science and Technology
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    • v.45 no.2
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    • pp.265-272
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    • 2003
  • This experiment was conducted to investigate the changes in meat quality characteristics on refri- gerated(4$^{\circ}C$) pork loin fed with supplemental levels of Bamboo vinegar(BV). Thirty pigs were divided into 3 groups of 10 pigs. Dietary levels of Bamboo vinegar 0%(control), 2% and 4% were included in experimental diets of each of the groups. The pH value was decreased(P<0.05) in 2% and 4% BV compared to the control after 3d of storage. Lightness was increased(P<0.05) in 2% and 4% BV compared to the control at 1d and 3d. Redness was decreased(P<0.05) in 4% VB compared to the control at 1d and 3d. The 2% and 4% BV showed a significant(P<0.05) increase in yellowness throughout the whole experiment compared to control. Cooking loss was increased(P<0.05) in 2% and 4% BV compared to the control after 3d of storage. Shear force was decreased(P<0.05) in 2% and 4% BV compared to control at 1d and 3d. TBA was decreased(P<0.05) in 2% and 4% BV at 6d and 9d. Total microbial counts was decreased(P<0.05) in 2% and 4% BV compared to control. The 2% and 4% BV scored higher(P<0.05) in odor evaluation compared to the control at 1d and 3d. The 2% and 4% BV also scored higher(P<0.05) than the control in the evaluation of appearance at 1d. The taste was increased(P<0.05) in 2% and 4% BV compared to control at 1d, 3d, and 6d. These results showed that the addition of 2% or 4% BV improved the meat quality and storage characteristics of refrigerated pork.

Differences in Root Growth Characteristics of Creeping Bentgrass and Kentucky Bluegrass Sod (크리핑 벤트그래스와 켄터키 블루그래스 뗏장의 뿌리생육 특성 차이)

  • Woo, Jong-Goo;Lee, Dong-Ik;Lee, Song-Ho
    • Asian Journal of Turfgrass Science
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    • v.21 no.1
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    • pp.23-37
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    • 2007
  • This study was carried out to investigate the characteristics of root growth in Kentucky bluegrass sod(KBS) and creeping bentgrass sod(BGS) transplanted in summer(August 9) and fall(September 19), respectively. Hydroponic system was also used to observe rooting development in the study. Root development differed in KBS by transplanting time. It reached to more than 5 cm after 100 days In summer and 50 days in fall. However, BGS's root grew over 6cm after 40 days, regardless of the season. There was no significant differences in BGS, regardless of any cutting treatment. In the case of KBS, it was best with sod culled with 0.5cm deep and 1.5cm long. But it grew beyond 5 cm in root growth under any treatment after 40 days in transplanting. In a hydroponic study, BGS produced root over 100cm for 80 days through a summer season. However, the root of KBS did only grow in condition below $20^{\circ}C$. These results indicated that root growth characteristics were variable in BGS and KBS. It was considered that rooting development of BGS might be improved with sufficient irrigation in summer, and KBS grows well in lower temperature of $10{\sim}18^{\circ}C$, as compared with BGS. As to establishing the lawn with a sodding method, it should be careful in transplanting time, especially KBS.

The study of binocular function of college students (대학생들의 시기능에 대한 연구)

  • Cho, Young-Rae;Park, Hyun-Ju;Seo, Ji-Keun;Seong, Jeong-Sub;Kim, Jae-Min
    • Journal of Korean Ophthalmic Optics Society
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    • v.10 no.2
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    • pp.103-110
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    • 2005
  • Binocular vision had a short history in Korea. As there were many near works in these days, the needs about comparative study have been increased. There was related to both refractive error and binocular anomalies, but it is difficult to applying for binocular vision expected findings in itself due to the fact that Korean differ from foreigner. Objects were 100 adults in 18-36 years old ages, The test was Von Gaefe method and used aparatus was phoropter(Shinnippon VT10)and visual chart(Shinnippon CT30). According to interview results was that symptom in near works were headaches 28.0%, blinking 27.3%, red eye 25.1%, eyepain 15.6%, watering 15.3%, itch 12.2%, photophobia 8.5% and eye strain 7.4%. A people who have above ${\pm}0.50$ D refractive error in total objectives (100-male 45/female 55) were classified into ametropia. There was a results such as emmetropia (12.0%), ametropia(88.0%), exophoria(32.0%), esophoria(12.0%). Far negative relative convergence were that in case of high 43.0%, in case of low 7.0%. Far positive relative convergence were that in case of high 15.0%, in case of low 38.0%. Near phoria was exophoria(32.0%), esophoria(12.0%). Near negative relative convergence were that in case of high 23.0%, in case of low 38.0%. Far positive relative convergence were that in case of high 29.0%, in case of low 23.0%. Near negative relative accommodation were that in case of high 10.0%, in case of low 14,0%, Far positive relative convergence were that in case of high 69.0%, in case of low 12.0%. Results were different from expected findings, and especially positive relative accommodation was very high, However, We suggest that the expected findings in Korea for several subjects must study in binocular function.

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The Effect of Cyclic Load on Different Femoral Fixation Techniques in Anterior Cruciate Ligament Reconstruction (전방십자인대 재건시 이식건의 대퇴골측 고정에 대한 주기성인장부하의 효과)

  • Song Eun-Kyoo;Kim Jong Seok
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.2 no.1
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    • pp.28-36
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    • 2003
  • Purpose: To determine and to compare the effects of cyclic loading on the fixation strength of different femoral fixation methods in ACL reconstruction. Materials and Methods: Biomechanical test using an Instron(R) machine (Model No.5569. Mass, U.S.A) were carried out to compare the pull out strength of six different femoral fixation techniques after a cyclic loading in 72 Yorkshire pig knees. The graft-bone complex was cyclically loaded between 30N and 150N at 50 mm/min rate for 1000 cycles and maximal tensile testing was performed. A preload of 30N was applied to the graft along the axis of the tunnel 15 minutes. ANOVA and the Duncan multiple comparison test was used for the statistical analysis. Results: The mean maximum tensile strength of femoral fixation before and after the cyclic loading test were 1003.4$\pm$145N and 601.1$\pm$154N in hamstring-LA screw(R) group, 595.5$\pm$104N and 360.7$\pm$56N in hamstring-Bioscrew(R) group, 1431.7$\pm$135N and 710.7$\pm$114N in hamstring-Semifix(R) group, 603.6$\pm$54N and 459.1$\pm$46N in hamstring-Endobutton(R) fixation group, 1067.4$\pm$145 and 601.8$\pm$134N in the BPTB-Titanium interference screw group, and 987.1$\pm$168N and 588.7$\pm$124N in the BPTB-Bioscrew(R) group. And these data illustrated that cyclic loading reduces the maximum tensile strength by 40 $\%$, 39 $\%$, 50 $\%$, 24 $\%$, 44 $\%$, 40 $\%$ respectively. Conclusions: With the results of these experiments it should be emphasized that rehabilitation exercises after anterior cruciate ligament reconstruction should be executed with precaution as the repetitive flexion and extension of the knee would compromise the maximum tensile strength of the graft tendon.

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A Simple, Sensitive, and Specific HPLC Analysis of Tissue Polyamines using FNBT Derivatization: Its Application on the Study of Polyamine Metabolism in Regenerating Rat Liver (생체의 Polyamine-분석을 위하여 FNBT-유도체를 이용하는 간편하고 특이적이며 예민한 Isocratic RP-HPLC 분석법과 재생성 흰쥐-간의 Polyamine-대사의 변동에 관한연구)

  • Choi, Sang-Hyun;Kim, Hyung-Gun;Park, Hong-Ik;Chun, Boe-Gwun
    • The Korean Journal of Pharmacology
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    • v.24 no.2
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    • pp.233-240
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    • 1988
  • A simple and selective isocratic HPLC method for the analysis of tissue polyamine contents is described and applied on the study of the changes of the hepatic polyamine contents after partial hepatectomy in male rats. The hepatic polyamines are extracted with 0.4 M perchloric acid containing 2 mM disodium EDTA, and then the extract is redissolved in 100 ul of 1 M sodium carbonate and incubated with 300 ul of FNBT-dimethylsulfoxide (1: 100) mixture. The N-2'-nitro-4'-trifluoromethylphenyl drivatives of polyamines are separated through a ERC-ODS column in an isocratic mode with an acetonitrile-water (80:20) mobile phase within 20 min. per a sample, while monitoring the effluent at 242 nm. This improved method which could detect subnanogram of each polyamines is highly specific and reproducible as evidenced by the application of it on the study of the changes of polyamine contents in the regenerating rat liver after partial hepatectomy.

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Effects of SiO2 Incorporation on Catalytic Performance and Physico-Chemical Properties of Iron-Based Catalysts for the Fischer-Tropsch Synthesis (Fischer-Tropsch 합성반응용 Fe계 촉매의 성능 및 물리화학적 특성에 미치는 SiO2 첨가효과)

  • Hyun, Sun-Taek;Chun, Dong Hyun;Kim, Hak-Joo;Yang, Jung Hoon;Yang, Jung-Il;Lee, Ho-Tae;Lee, Kwan-Young;Jung, Heon
    • Korean Chemical Engineering Research
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    • v.48 no.3
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    • pp.304-310
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    • 2010
  • The FTS(Fischer-Tropsch synthesis) was carried out over precipitated iron-based catalysts with or without $SiO_2$ in a fixed-bed reactor at $250^{\circ}C$ and 1.5 MPa. The catalysts with $SiO_2$ showed much higher catalytic activity for the FTS than those without $SiO_2$, displaying excellent stability during 144 h of reaction. The X-ray diffraction and $N_2$ physisorption revealed that the catalysts with $SiO_2$ showed enhanced dispersion of $Fe_2O_3$ compared with those without $SiO_2$. Also, the results of temperature-programmed reduction by $H_2$ showed that the addition of $SiO_2$ markedly promoted the reduction of $Fe_2O_3$ into $Fe_3O_4$ and FeO at low temperatures below $260^{\circ}C$. In contrast, surface basicity of the catalysts, which was analyzed by temperature-programmed desorption of $CO_2$, decreased as a result of $SiO_2$ addition. We attribute the high and stable performance of the catalysts with $SiO_2$ to the improved dispersion and reducibility by the $SiO_2$ addition.

Antioxidative Properties of Extract/Fractions of Suaeda asparagoides and Salicornia herbacea Extracts(I) (함초(나문재 및 퉁퉁마디) 추출물의 항산화 작용에 관한 연구(I))

  • Park, Soo-Nam;Jeon, So-Mi;Kim, So-I;Ahn, Jeung-Youb
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.33 no.3
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    • pp.145-152
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    • 2007
  • In this study, the antioxidative effects of Sueada asparagoides and Salicornia herbacea extracts were investigated. The free radical(1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity($FSC_{50}$) of extract/fractions of Sueada asparagoides was in the order: 100 % ethanol extract(329.33 ${\mu}g/mL$) < 50 % ethanol extract(40.73) < ethylacetate fraction(13.87) < deglycosylated aglycone fraction (7.80). In case of Salicornia herbacea, the free radical scavenging activities of ethylacetate fraction and aglycone fraction were 13.87 and 7.80 ${\mu}g/mL$, respectively. Reactive oxygen species(ROS) scavenging activities($OSC_{50}$) of Sueada asparagoides and Solicornia herbacea extracts on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The order of ROS scavenging activity of Sueada asparagoides extracts was 50 % ethanol extract($OSC_{50}$, $0.99{\mu}g/mL$) < ethylacetate fraction (0.05) < aglycone fraction (0.03). Aglycone fraction showed the most prominent scavenging activity. In case of Salicornia herbacea, the ROS scavenging activities of ethylacetate fraction and aglycone fraction were 0.10 and 0.20 ${\mu}g/mL$, respectively. The protective effects of extract/fractions of Sueada asparagoides and Salicornia herbacea on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethanol extract(100%) of Sueada asparagoides diminished photohemolysis in a concentration dependent manner($1{\sim}100{\mu}g/mL$). Particularly deglycosylated aglycone fraction exhibited the most prominent celluar protective effect($\tau_{50}$, 310 min at 50 ${\mu}g/mL$). In case of Salicornia herbacea, ethylacetate fraction exhibited more potent protective effect. These results indicate that extract/fractions of Sueada asparagoides can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS.