• Title/Summary/Keyword: Transition study

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A Scanning Calorimetric Study of the Effect of Clover Saponin on Liposomal Phospholipid Membrane

  • Bae, Song-Ja;Han, Suk-Kyu;Im, Kwang-Sik;Kim, Nam-Hong
    • Archives of Pharmacal Research
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    • v.11 no.3
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    • pp.181-184
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    • 1988
  • The effect of clover saponin on the phase transition of liposomal lipid bilayers of dimyristoyl phosphatidylcholine was investigated with differential scanning calorimetry. The thermograms of the liposomal bilayers incorporated with the clover saponin were obtained, and the enthalpy changes and the sizes of cooperative unit of the transition were calculated. The results showed that incorporation of the clover saponin into the liposomal bilayers effectively reduced the transition temperature at which the transition from solid state to liquid-crystalline state occurs, and broadened the thermogram peaks. It also reduced the size of cooperative unit of the transition. These results indicate that the clover saponin might have significant effect on the fluidity of biological membranes.

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Effects of Alkali Oxides on the Cristobalitization of Quartz in Whiteware Body (자기소지에서 Quartz의 Cristobalite화에 미치는 알칼리 금속산화물의 영향)

  • 정창주;김남일;오경영
    • Journal of the Korean Ceramic Society
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    • v.29 no.12
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    • pp.981-989
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    • 1992
  • This is a study on the effects of cristobalite transition of quartz in semi-vitrious whiteware body, as addition of alkali and alkali earth oxides, prepared by pottery stone, feldspar, kaolin and clay minerals. The amounts of ${\alpha}$-quartz to ${\alpha}$-cristobalite transition, F.O.C. (fraction of cristobalite), were increased with firing temperature. In MgO added body, ${\alpha}$-quartz was decreased and the formation of cristobalite was increased. Effects of K2O addition was remarkably decreased the formation of cristobalite. Additive effects of MgO and K2O were confirmed that it was very different to variation of transition temperature of metakaolinite to Si-Al spinel structure in thermal reaction of kaolinite minerals. Result CaO addition was ineffective to transition temperature, and the transition temperature in Na2O added body was decreased, but relative intensity of quartz and cristobalite crystal in XRD results was decreased. This was characterized by the effects on the formation of liquid phase much more.

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On the strong attractive force dependence of the surface phase transition : Qualitative consideration from the occupation statistics (표면상변이의 강인력 의존성 : 점유통계를 이용한 정성적 고찰)

  • 김철호
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.7 no.4
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    • pp.573-577
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    • 1997
  • Surface phase transition is known to be observed at the system that there exists a strong attractive potential between particles adsorbed. This study presents a dependence of the surface phase transition on strong attractive force using a simple occupation statistical method. It was found that the system exhibits a phase transition from the vacuum phase into the population phase and the critical pressure also increases with the temperature. This fact indicates that these results explain well qualitatively the surface phase transition.

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Evaluation of the Ductile-Brittle Transition Behavior of fracture Toughness by Material Degradation (열화에 따른 파괴인성치의 연성-취성 천이거동 평가)

  • 석창성;김형익;김상필
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.5
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    • pp.140-147
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    • 2003
  • As the huge energy transfer systems like as nuclear power plant and steam power plant are operated for a long time at a high temperature, mechanical properties are changed and ductile-brittle transition temperature is raised by degradation. So it is required to estimate degradation in order to assess the safety, remaining life and further operation parameters. The sub-sized specimen test method using surveillance specimen was developed for evaluating the integrity of metallic components. In this study, we would like to present the evaluation technique of the ductile-brittle transition temperature by the sub-sized specimen test. The four classes of the thermally aged 1Cr-1Mo-0.25V specimens were prepared using an artificially accelerated aging method. The tensile test and fracture toughness test were performed. The results of the fracture toughness tests using the sub-sized specimens were compared with the evaluation technique of the ductile-brittle transition temperature.

A Study on the Synthesis and Property of Azide Type Photosensitive Resin (Azide형 감광성수지의 합성과 특성에 관한 연구)

  • 조가람
    • Journal of the Korean Graphic Arts Communication Society
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    • v.14 no.1
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    • pp.115-131
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    • 1996
  • The PVT(pressure-volume-temperature) relation of main-chain dimer liquid crystals having structures such as $\alpha$,$\omega$-bis[(4,4`-cyanobiphenyl) oxy] alkane(CBA-n with=9, 10) were studied. these dimer liquid crystals are known to form an enantiotropic nematic mesophase. In this work, we have determined the volume change as a function of temperature and pressure by using a GNOMIX PVT apparatus. In the V-Tcurves obtaind from isobaris mearements on various pressures, volume changes were observed at the nematic-isotropiz and nematic-crystal phase transitions. The volume changes at the transition exhibit slight odd-even effect with respect to the number of methylene unit n. The values of the (S)v obtained at the NI transition for CBA-9 and -10 were 6.9 and 12.6J/mol k. The valuesof (S)v for the CN transition were estimated on the basis of DSC(differential scanning calorimetry) data: 58.8(CBA-9) and 65.3J/mol k (CBA-10). For both transition, it was found that the correction about the volume change is significant, ranging from 40% to 60% of the total transition entropy observed under constant pressure.

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Monoamine Oxidase Inhibitors Attenuate Cytotoxicity of 1-Methyl-4-phenylpyridinium by Suppressing Mitochondrial Permeability Transition

  • Lee, Chung-Soo
    • The Korean Journal of Physiology and Pharmacology
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    • v.10 no.4
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    • pp.207-212
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    • 2006
  • Mitochondrial permeability transition has been shown to be involved in neuronal cell death. Mitochondrial monoamine oxidase (MAO)-B is considered to play a part in the progress of nigrostriatal cell death. The present study examined the effect of MAO inhibitors against the toxicity of 1-methyl-4-phenylpyridinium $(MPP^+)$ in relation to the mitochondrial permeability transition. Chlorgyline (a selective inhibitor of MAO-A), deprenyl (a selective inhibitor of MAO-B) and tranylcypromine (nonselective inhibitor of MAO) all prevented cell viability loss, cytochrome c release, caspase-3 activation, formation of reactive oxygen species and depletion of GSH in differentiated PC12 cells treated with $500\;{\mu}M$$MPP^+$. The MAO inhibitors at $10\;{\mu}M$ revealed a maximal inhibitory effect and beyond this concentration the inhibitory effect declined. On the basis of concentration, the inhibitory potency was tranylcypromine, deprenyl and chlorgyline order. The results suggest that chlorgyline, deprenyl and tranylcypromine attenuate the toxicity of $MPP^+$ against PC12 cells by suppressing the mitochondrial permeability transition that seems to be mediated by oxidative stress.

Linear Interpolation Transition of Character Animation for Immediate 3D Response to User Motion

  • Lim, Sooyeon
    • International Journal of Contents
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    • v.11 no.1
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    • pp.15-20
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    • 2015
  • The purpose of this research is to study methods for performing transition that have visual representation of corresponding animations with no bounce in subsequently recognized user information when attempting to interact with a virtual 3D character in real-time using user motion. If the transitions of the animation are needed owing to a variety of external environments, continuous recognition of user information is required to correspond to the motion. The proposed method includes linear interpolation of the transition using cross-fades and blending techniques. The normalized playing time of the source animation was utilized for automatically calculating the transition interpolation length of the target animation and also as the criteria in selecting the crossfades and blending techniques. In particular, in the case of blending, the weighting value based on the degree of similarity between two animations is used as a blending parameter. Accordingly, transitions for visually excellent animation are performed on interactive holographic projection systems.

Analysis on the Reinforcement Effect for Large Type Sleeper on Transition zone between Earthwork and Tunnel (터널/토공 접속부에 대한 대형침목 보강효과 분석)

  • Lee, Jin-Wook;Choi, Chan-Yong;Lee, Il-Wha
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1279-1286
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    • 2006
  • It is very important to pay careful attention to construction of earthwork/tunnel transition zone for railway. The transition zone of the railway is the section which roadbed stiffness is suddenly varied. Differences in stiffness have dynamic effects and these increase the forces in the track and the extent of deformation. In this study, performance of transition zone was investigated through the field tests. The wheel loads and sleeper settlement were measured after installing field testing sections.

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Wall Pressure Fluctuations of the Boundary Layer Flow at the Nose of and Axisymmetric Body (축대칭 물체 선단에서 발생하는 경계층 내 벽면 변동 압력에 관한 연구)

  • 신구균;홍진숙;김상윤;김상렬;박규철
    • Journal of KSNVE
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    • v.10 no.4
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    • pp.602-609
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    • 2000
  • When an axisymmetric body moves through air the boundary layer near the stagnation region remains laminar and subsequently it goes through transition to turbulent. The experimental investigation described in this paper concerns the characteristics of wall pressure fluctuations at the initial stage of boundary layer flow including transition. Flush-mounted microphones are used to measure the wall pressure fluctuations at the transition and turbulent boundary layer region of a blunt axisymmetric body in the low noise wind tunnel. It if found from this study that the wall pressure fluctuations in the transition region is higher than that in the turbulent region.

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Typology of men's perceived costs and benefits about the transition to parenthood (남성의 부모기로의 전이에 대한 보상-대가 지각의 유형)

  • 송지은
    • Journal of the Korean Home Economics Association
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    • v.32 no.4
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    • pp.73-83
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    • 1994
  • This study tries to develop the typology of relative costs-benefits perception about the transition to parenthood and explore the group differences in the socio-demographic variables, family context variables, and social support level. For these purpose data was gathered from 342 fathers who experienced the transition to parenthood within past three years. The major findings were as follow. 1. The level of men's perceived benefits about the transition to parenthood was higher than the level of costs. 2. The typology of relative costs-benefits perception about the transition to parenthood were , , and . The discriminant variables among 4 groups were marital satisfaction. birth planning educational attainment, and kinship's emotional support.

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