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Microstructure and Conductivity of Cu-Nb Microcomposites Fabricated by Bundling and Drawing Process (다발체형성과 인발공정에 의해 제조된 Cu-Nb 미세복합재료의 미세조직과 전도도)

  • Kwon, Hoi-Joon;Hong, Sun-Ig;Jee, Kwang-Koo
    • Korean Journal of Materials Research
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    • v.11 no.2
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    • pp.115-119
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    • 2001
  • The electrical properties of heavily drawn bundled Cu- Nb filamentary microcomposite wires were examined and correlated with the microstructural changes caused by thermomechanical treatments. The cross sectional shape of Nb filaments in wires fabricated by bundling and drawing appear straight or slightly curved. The different shape of Nb filaments is attributed to the break- up and cylinderization of Nb filaments during the bundling process at high temperatures. The resistivity of Cu-Nb microcomposites is predominantly controlled by electron scattering at Cu-Nb interfaces. The decrease of the conductivity below the annealing temperature of $400^{\circ}C$ is due to the increasing contribution of the scattering associated with coherency strains of needle- shaped precipitates. The slight decrease of the resistivity ratio (${\rho}_{295K}/{\rho}_{75K}$) is also due to the precipitation of Nb atoms. The increase in conductivity in Cu-Nb microcomposites at an annealing temperature of 50$0^{\circ}C$ is due to the coarsening and spheroidization of Nb filaments.

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The Prediction of Structural Behavior for Composite Pressure Vessel with Changed Dome Shape (돔 형상 변화에 따른 복합재 압력용기의 구조 거동 예측)

  • Hwang, Tae-Kyung;Park, Jae-Byum;Kim, Hyung-Kun;Doh, Young-Dae
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.11a
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    • pp.288-292
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    • 2008
  • Dome shape design method of filament wound (FW) composite pressure vessel, which can create various dome shape with fixed boss opening, was suggested. And, the performance indices (PV/W) for composite pressure vessel with same boss opening but different dome shape were investigated by finite element analysis (FEA) and hydro-test. The FEA showed good agreement with test results for burst pressure. Generally, as the dome shape of pressure vessel was changed to flat dome, the inner volume is increased and the burst pressure is decreased. In the case of above ${\rho}_o$=0.54, the performance index showed decreased value due to the low burst pressure. However, at ${\rho}_o$=0.35, the dome shape change brings not significant reduction of burst pressure and performance index.

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Analysis on the spread variance by the spill-over spot on the spark sonance

  • Kim, Jeong-lae;Hwang, Kyu-sung
    • International Journal of Advanced Culture Technology
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    • v.7 no.1
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    • pp.237-242
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    • 2019
  • Spark variance technique is melded the jagged spill-over-sonance status of the glitter-differentiation knowledge level (GDKL) on the spark knowledge gestalt. The knowledge level condition by the spark knowledge gestalt system is comprised with the spill-over-sonance system. As to search a spot of the glitter situation, we are obtained of the spark value with black-red dot by the spill-over upper structure. The concept of knowledge level is comprised the reference of glitter-differentiation level for variance signal by the spark sonance gestalt. Further presenting a jagged variance of the GDKL of the maximum in terms of the spill-over-sonance gestalt, and spark spot sonance that was the a spark value of the far variance of the Spa-kg-FA-${\rho}_{MAXN}$ with $17.68{\pm}2.22units$, that was the a spark value of the convenient variance of the Spa-kg-CO-${\rho}_{MAXN}$ with $7.55{\pm}0.59units$, that was the a spark value of the flank variance of the Spa-kg-FL-${\rho}_{MAX}$ with $2.70{\pm}0.48units$, that was the a spark value of the vicinage variance of the Spa-kg-VI-${\rho}_{MAX}$ with $0.48{\pm}0.05units$. The spill-over sonance will be to appraisal at the jagged ability of the spill-over-sonance gestalt with black-red dot by the spark knowledge level on the GDKL that is presented the glitter-differentiation gestalt by the knowledge level system. Spill-over knowledge system will be possible to restrain of a gestalt by the special signal and to employ a spark data of spill-over sonance level.

Polysaccharides from Panax ginseng promote intestinal epithelial cell migration through affecting the Ca2+ related regulators

  • Huibin Zhu;Jianhong Cao;Xinyi Liang;Meng Luo;Anrong Wang;Ling Hu;Ruliu Li
    • Journal of Ginseng Research
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    • v.47 no.1
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    • pp.89-96
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    • 2023
  • Background and aim: Panax ginseng, a key herbal medicine of replenishing Qi and tonifying Spleen, is widely used in the treatment of gastrointestinal diseases in East Asia. In this study, we aim to investigate the potential effects and mechanisms of polysaccharides from P. ginseng (PGP) on intestinal mucosal restitution which is one of the crucial repair modalities during the recovery of mucosal injury controlled by the Ca2+ signaling. Methods: Rat model of intestinal mucosal injury was induced by indomethacin. The fractional cell migration was carried out by immunohistochemistry staining with BrdU. The morphological observations on intestinal mucosal injury were also performed. Intestinal epithelial cell (IEC-6) migration in vitro was conducted by scratch method. Western-blot was adopted to determine the expressions of PLC-𝛾1, Rac1, TRPC1, RhoA and Cav-1. Immunoprecipitation was used to evaluate the levels of Rac1/PLC-𝛾1, RhoA/TRPC1 and Cav-1/TRPC1. Results: The results showed that PGP effectively reduced the assessment of intestinal mucosal injury, reversed the inhibition of epithelial cell migration induced by Indomethacin, and increased the level of Ca2+ in intestinal mucosa in vivo. Moreover, PGP dramatically promoted IEC-6 cell migration, the expression of Ca2+ regulators (PLC-𝛾1, Rac1, TRPC1, Cav-1 and RhoA) as well as protein complexes (Rac1/PLC-𝛾1, Cav-1/TRPC1 and RhoA/TRPC1) in vitro. Conclusion: PGP increases the Ca2+ content in intestinal mucosa partly through controlling the regulators of Ca2+ mobilization, subsequently promotes intestinal epithelial cell migration, and then prevents intestinal mucosal injury induced by indomethacin.

Correlation of the Speed of Enhancement of Hepatic Hemangiomas with Intravoxel Incoherent Motion MR Imaging (간혈관종의 조영증강속도와 복셀내비결집운동 MR영상과의 상관관계)

  • Yang, Dal Mo;Jahng, Geon-Ho;Kim, Hyun Cheol;Kim, Sang Won;Kim, Hyug-Gi
    • Investigative Magnetic Resonance Imaging
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    • v.18 no.3
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    • pp.208-218
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    • 2014
  • Purpose : To evaluate the relationship between the speed of enhancement of hepatic hemangiomas on gadolinium-enhanced MRI and ADC values by using various parameters, including the D, f, $D^*$ and $ADC_{fit}$ on intravoxel incoherent motion (IVIM) MR Imaging. Materials and Methods: The institutional review board approved this retrospective study. A total of 47 hepatic hemangiomas from 39 patients were included (20 men and 19 women). The hemangiomas were classified into three types according to the enhancement speed of the hepatic hemangiomas on gadolinium-enhanced dynamic T1-weighted images: rapid (Type A), intermediate (Type B), and slow (Type C) enhancement. The D, f, $D^*$ and $ADC_{fit}$ values were calculated using IVIM MR imaging. The diffusion/perfusion parameters and ADC values were compared among the three types of hemangiomas. Results: Both the $ADC_{fit}$ and D values of type C were significantly lower than those of type A (P = 0.0022, P = 0.0085). However, for the f and $D^*$, there were no significant differences among the three types. On DWI with all b values (50, 200, 500 and $800sec/mm^2$), the ADC values of type C were significantly lower than those of the type A (P < 0.012). For b values with $800sec/mm^2$, the $ADC_{800}$ values of the type C hemangiomas were significantly lower than those of type B (P = 0.0021). We found a negative correlation between hepatic hemangioma enhancement type and $ADC_{50}$ (${\rho}=-0.357$, P = 0.014), $ADC_{200}$ (${\rho}=-0.537$, P = 0.0001), $ADC_{500}$ (${\rho}=-0.614$, P = 0.0001), and $ADC_{800}$ (${\rho}=-0.607$, P = 0.0001). Therefore, four ADC values of $ADC_{50}$, $ADC_{200}$, $ADC_{500}$, and $ADC_{800}$ were decreased with decreasing enhancement speed. Conclusion: Hepatic hemangiomas had variable ADCs according to the type of enhancement, and the reduced ADCs in slowly enhancing hemangiomas may be related to the reduced pure molecular diffusion (D).

An Analysis of Anomalous Radon Variation Caused by M5.8 Gyeong-ju Earthquake (규모 5.8 경주 지진에 의한 토양 내 라돈농도의 이상변화 분석)

  • Kim, Jin-seop;Kim, Minjun;Kim, Sunwoong;Lee, Hyomin
    • Economic and Environmental Geology
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    • v.51 no.1
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    • pp.1-13
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    • 2018
  • The radon concentration in soil varies with environmental factors such as atmospheric temperature and pressure, rainfall and soil temperature. The effects of these factors, therefore, should be differentiate in order to analyzed the anomalous radon variation caused by earthquake events. For these reasons, a comparative analysis between the radon variations with environmental factors and the anomalous variations caused by Gyeong-ju earthquake occurred in September 12, 2016 has been conducted. Radon concentration in soil and environmental factors were continuously measured at a monitoring ste located in 58Km away from earthquake epicenter from January 01, 2014 to May 31, 2017. The co-relationships between radon concentration and environmental factors were analyzed. The seasonal average radon concentration(n) and the standard variation(${\rho}$) was calculated, and the regions of ${\pm}1{\rho}$ and ${\pm}2{\rho}$ deviations from seasonal average concentration were investigated to find the anomalous radon variation related to Gyeong-ju earthquake. Earthquake effectiveness and q-factor were also calculated. The radon concentration indicated the seasonal variation pattern, showing high in summer and low in winter. It increases with increasing air temperature and soil temperature, and has the positive co-relationships of $R^2=0.9136$ and $R^2=0.8496$, respectively. The radon concentration decreases with increasing atmospheric pressure, and has the negative co-relationships of $R^2=0.7825$. Four regions of ${\pm}2{\rho}$ deviation from average seasonal concentration (A1: 7/3~7/5, A2: 7/18, A3: 8/4~8/5, A4: 10/17~10/20) were detected before and after Gyeong-ju earthquake. A1, A2, A3 were determined as the anomalous radon variation caused by the earthquake from co-relationship analyses with environmental factors, earthquake effectiveness and q-factor. During the period of anomalous radon variation, correlation coefficients between radon concentration and environmental factors were significantly lowered compared to other periods such as air temperature ($R^2=0.2314$), soil temperature ($R^2=0.1138$) and atmospheric pressure ($R^2=0.0475$). Annual average radon concentration was also highest at 2016, the year of Gyeong-ju earthquake.

Estimation of Nondestructive Rice Leaf Nitrogen Content Using Ground Optical Sensors (지상광학센서를 이용한 비파괴 벼 엽 질소함량 추정)

  • Kim, Yi-Hyun;Hong, Suk-Young
    • Korean Journal of Soil Science and Fertilizer
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    • v.40 no.6
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    • pp.435-441
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    • 2007
  • Ground-based optical sensing over the crop canopy provides information on the mass of plant body which reflects the light, as well as crop nitrogen content which is closely related to the greenness of plant leaves. This method has the merits of being non-destructive real-time based, and thus can be conveniently used for decision making on application of nitrogen fertilizers for crops standing in fields. In the present study relationships among leaf nitrogen content of rice canopy, crop growth status, and Normalized Difference Vegetation Index (NDVI) values were investigated. We measured Green normalized difference vegetation index($gNDVI=({\rho}0.80{\mu}m-{\rho}0.55{\mu}m)/({\rho}0.80{\mu}m+{\rho}0.55{\mu}m)$) and NDVI($({\rho}0.80{\mu}m-{\rho}0.68{\mu}m)/({\rho}0.80{\mu}m+{\rho}0.68{\mu}m)$) were measured by using two different active sensors (Greenseeker, NTech Inc. USA). The study was conducted in the years 2005-06 during the rice growing season at the experimental plots of National Institute of Agricultural Science and Technology located at Suwon, Korea. The experiments carried out with randomized complete block design with the application of four levels of nitrogen fertilizers (0, 70, 100, 130kg N/ha) and same amount of phosphorous and potassium content of the fertilizers. gNDVI and rNDVI increased as growth advanced and reached to maximum values at around early August, G(NDVI) were a decrease in values of observed with the crop maturation. gNDVI values and leaf nitrogen content were highly correlated at early July in 2005 and 2006. On the basis of this finding we attempted to estimate the leaf N contents using gNDVI data obtained in 2005 and 2006. The determination coefficients of the linear model by gNDVI in the years 2005 and 2006 were 0.88 and 0.94, respectively. The measured and estimated leaf N contents using gNDVI values showed good agreement ($R^2=0.86^{***}$). Results from this study show that gNDVI values represent a significant positive correlation with leaf N contents and can be used to estimate leaf N before the panicle formation stage. gNDVI appeared to be a very effective parameter to estimate leaf N content the rice canopy.

Expression and Purification of Three Lipases (LipAD1, LipAD2, and LipAD3) and a Lipase Chaperone (LipBD) from Acinetobacter schindleri DYL129 (Acinetobacter schindleri DYL129 유래의 3개 lipases와 chaperone의 발현과 정제)

  • Kim, Sun-Hee;Lee, Yong-Suk;Jeong, Hae-Rin;Pyeon, Hyo-Min;You, Ju-Soon;Choi, Yong-Lark
    • Journal of Life Science
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    • v.29 no.4
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    • pp.492-498
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    • 2019
  • Previously, three kinds of lipases, lipAD1, lipAD2, and lipAD3, and lipase chaperone, lipBD, of Acinetobacter schindleri DYL129 isolated from soil sample were reported. In this report, three lipase and lipase chaperone were cloned into the pET32a(+) or pGEX-6P-1 vectors for protein expression in Escherichia coli, and named as pETLAD1, pETLAD2, pETLAD3 and pETLBD or pGEXLAD1, pGEXLAD 2, pGEXLAD3 and pGEXLBD, respectively. Protein expression rate was higher in pET system than in pGEX system. Although LipAD1 and LipAD2 were produced as inclusion bodies, their expression levels were high. So LipAD1 and LipAD2 could be solubilized in 8 M urea buffer and purified. LipAD3 and LipBD were overexpressed in soluble form and purified. Those proteins were purified by His-tag affinity chromatography connected in AKTA prime system. The activities of the purified lipases were demonstrated with 1% tributyrin agar plate. After purification, molecular mass was determined with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. LipAD1 showed high activity toward ${\rho}$-nitrophenyl acetate and ${\rho}$-nitrophenyl butyrate, LipAD2 showed high activity toward ${\rho}$-nitrophenyl acetate and ${\rho}$-nitrophenyl myristate, and LipAD3 showed high activity toward ${\rho}$-nitrophenyl acetate, ${\rho}$-nitrophenyl butyrate, and ${\rho}$-nitrophenyl miristate, respectively. Three lipases, LipAD1, LipAD2, and LipAD3, showed optimal reaction at $50^{\circ}C$ using ${\rho}$-nitrophenyl butyrate, as substrate.

Die dialektische Aporetik bei Aristoteles und ihre methodologische Funktion (아리스토텔레스에게서 아포리아의 변증적 탐구술과 그 방법론적 기능)

  • Lee, Jae-hyun
    • Journal of Korean Philosophical Society
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    • v.126
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    • pp.263-293
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    • 2013
  • Die vorliegende Abhandlung beachtet die methodologische $N{\ddot{u}}tzlichkeit$ der Dialektik $f{\ddot{u}}r$ die philosophische $Wissenschaftst{\ddot{a}}tigkeit$ des Aristoteles in einer besonderen Aufmerksamkeit auf den Begriff "${\delta}{\iota}{\alpha}{\pi}o{\rho}{\varepsilon}{\iota}{\nu}$". Bei Aristoteles bedeutet "${\delta}{\iota}{\alpha}{\pi}o{\rho}{\varepsilon}{\iota}{\nu}$" 'das durchaus $gr{\ddot{u}}ndliche$ Untersuchen einer Aporie', und eine solche Untersuchungsweise folgt der Dialektik. Deshalb beabsichtige ich zuerst, durch eine Begriffsanalyse und - interpretation von "${\delta}{\iota}{\alpha}{\pi}o{\rho}{\varepsilon}{\iota}{\nu}$" die dialektische Aporetik zu bestimmen als eine Argumentationsmethode nicht nur in einer dialogischen, sondern auch in einer nicht-dialogischen Situation. Besonders will ich einen methodologischen Grund $daf{\ddot{u}}r$ suchen, dass ein allein Forschender in der nicht-dialogischen Situation die dialektische Aporetik verwendet, indem ich einen Text von "De caelo" II 13, 294b 6~13 interpretiere. $N{\ddot{a}}mlich$ betont Aristoteles in Bezug auf den Durchgang der $Wissenschaftst{\ddot{a}}tigkeit$ eine Forderung der selbstkritischen Haltung, die der allein Forschende sich selbst seine Untersuchung in $R{\ddot{u}}cksicht$ auf die anderen Untersuchungen und auch auf die vorhersehbaren Hypothesen ${\ddot{u}}berpr{\ddot{u}}fen$ und verifizieren, um die aus seiner Untersuchung zu entdeckenden Aporien auf die dialektische Weise zu $l{\ddot{o}}sen$. Und diese Position von Aristoteles kann der wichtige Grund $daf{\ddot{u}}r$ sein, den fachsprachlichen Sinn von "${\delta}{\iota}{\alpha}{\pi}o{\rho}{\varepsilon}{\iota}{\nu}$" als auch den wissenschaftlichen Sinn der dialektischen Untersuchung der Aporie richtig verstehen und $erkl{\ddot{a}}ren$ zu $k{\ddot{o}}nnen$. Zuletzt bin ich in der Absicht, die dialektische Aporetik und ihre Funktion in drei Modeln zu formulieren und einige Beispiele $f{\ddot{u}}r$ jedes Model vorzustellen, um zu zeigen, auf welche Art und Weise Aristoteles die dialektische Aporetik $f{\ddot{u}}r$ den Lauf seiner Theoriebildung in der Tat anwendet. Durch solchen Versuch $w{\ddot{u}}nsche$ ich, dass meine Untersuchung ${\ddot{u}}ber$ die dialektische Aporetik etwas besseres $Verst{\ddot{a}}ndnis$ $f{\ddot{u}}r$ die wissenschaftliche Bedeutung der aristotelischen Dialektik anbieten $k{\ddot{o}}nnte$, und auch dass diese Studie als bedeutsame Basisdaten zu einer noch tieferen Forschung und $Verst{\ddot{a}}ndigung$ ${\ddot{u}}ber$ die philosophische Haltung und Methode des Aristoteles betrachtet werden $k{\ddot{o}}nnte$.

Kinetics and Mechanism of the Pyridinolysis of (2R,4R,5S)-(+)-2-Chloro-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine 2-Sulfide in Acetonitrile

  • Barai, Hasi Rani;Lee, Hai-Whang
    • Bulletin of the Korean Chemical Society
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    • v.33 no.3
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    • pp.1047-1051
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    • 2012
  • The nucleophilic substitution reactions of (2R,4R,5S)-(+)-2-chloro-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine 2-sulfide with X-pyridines are investigated kinetically in acetonitrile at $5.0^{\circ}C$. The free energy relationships for substituent X variations in the nucleophiles exhibit biphasic concave upwards with a break point at X = 3-Ac. Unusual positive $\rho_X$ (= +4.73) and negative ${\beta}_X$ (= -0.75) values are obtained with the weakly basic pyridines, and rationalized by the isokinetic relationship with isokinetic temperature at $t_{ISOKINETIC}=39.3^{\circ}C$. A concerted mechanism involving a change of nucleophilic attacking direction from a frontside attack with the strongly basic pyridines to a backside attack with the weakly basic pyridines is proposed on the basis of greater magnitudes of selectivity parameters ($\rho_X$ = -6.15 and ${\beta}_X$ = 1.11) with the strongly basic pyridines compared to those ($\rho_X$ = 4.73 and ${\beta}_X$ = -0.75) with the weakly basic pyridines.