• 제목/요약/키워드: stepwise addition

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영양소분지에 분포하는 경상누층군에 대한 고지자기 연구 (Paleomagnetism of the cretaceous sedimentary rocks in the Yongyang Sub-Basin)

  • 도성재
    • 자원환경지질
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    • 제32권2호
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    • pp.189-201
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    • 1999
  • Paleomagnetic and rock magnetic investigations have been carried out for the Cretaceous Hanyang Group, exposed in the Yongyang Sub-Basins within the Kyeongsang Basin, eastern South Korea. A total of 452 oriented core samples was drilled from 31 sits for the study. The in-situ site mean direction is more dispersed than the mean direction after bedding correction, indicating that the fold test is positive at 95% confidence level. In addition, the stepwise unfolding of the characteristic remanent magfold test is positive at 95% confidence level. In addition, the stepwise unfolding of the characteristic remanent magnetization reveals that a maximum value of k is observed at 90% unfolding. Furthermore, the rock magnetic investigations and electron microscope observations of the representative samples show that the main magnetic carrier of the Hayang Group is the detrital specular hematite of single and pseudo-single domain sizes with negligible contribution of pigmentary hematite grains. These results collectively imply that the ChRM direction is the primary component acquired at the time of the formation of the strata. Provided the primary nature of the ChRM, a magnetostratigraphic correlation between polarities of the studied formation and the Geomagnetic Time Scale indicates that the Hayang Group in the Yongyang Sub-Basin can be correlated to the Cretaceous Long Normal superchron. The paleomagnetic pole position from this study is significantly different from those of the Hayang group in the Euiseong the Milyang sub-Basins. Rather the paleomagnetic pole position of the Hayang Group of the study area is closer to that of the Quaternary period or present time of the Korean Peninsula. It is hypothesized that the study area might be rotated about 25$^{\circ}$ aticlockwise with respect to the Euiseong and Milyang Sub-Basins after the formation of the strata and aquisition of the ChRM, although there is not enough geologic evidence supporting the rotation hypothesis.

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유한요소 구조해석을 위한 객체지향 전처리 프로그램에 관한 연구 (A Study on Object-Oriented Preprocessing Program for Finite Element Structural Analysis)

  • 신영식;서진국;송준엽;우광성
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1994년도 봄 학술발표회 논문집
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    • pp.25-32
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    • 1994
  • The pre-processor for finite to element structural analysis considering the user-friendly device is developed by using GUI. This can be used on WINDOWS' environment which is realized the multi-tasking and the concurrency by object-oriented paradigm. Data input can be done easily through menu, dialog box, automatic stepwise input and concurrent representation with the structural geometry on multiple windows. It in designed to control integratedly the pre-processing, execution and the post-processing of the finite element structural analysis program on multiple windows, and input data can be seen with result outputs at the same time. In addition, the object-oriented programming environment makes convenient revision and addition of the program components for expanding the scope of analysis and making better user environment.

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대장균에서 대량 발현된 Streptomyces peucetius유래 Aklavinone 11-Hydroxylase효소의 최적 가용화 조건 (Optimization of Refolding Conditions for the Aklavinone 11-Hydroxylase of Streptomyces peucetius Overexpressed in Escherichia coli.)

  • 민우근;홍영수;최용경;이정준;홍순광
    • 한국미생물·생명공학회지
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    • 제26권4호
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    • pp.365-368
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    • 1998
  • The aklavinone 11-hydroxylase which was overexpressed using T7 promoter in E. coli could be detected in SDS-PAGE only in insoluble precipitate without any detectable enzyme activity. The insoluble enzyme was solubilized in 6M guanidine$.$HCl solution and their refolding ability was tested under various conditions. When the enzymatic activity was checked by the bioconversion experiment, stepwise dialysis against 6M, 3M, 1M guanidine$.$HCl and finally 100 mM potassium phosphate buffer of the solubilized protein gave the best bioconversion efficiency. The aklavinone 11-hydroxylase showed its enzymatic activity in the reaction buffer containing NADPH with vigorous shaking. The enzymatic activity was lost during partial purification and regained by the addition of crude extract of S. lividans in the reaction mixture. This effect was confirmed to due to some low-molecular weight component(s) in the crude extract, because the addition of dialyzed crude extract could not recover the enzymatic activity.

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Polychotomous Machines;

  • Koo, Ja-Yong;Park, Heon Jin;Choi, Daewoo
    • Communications for Statistical Applications and Methods
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    • 제10권1호
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    • pp.225-232
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    • 2003
  • The support vector machine (SVM) is becoming increasingly popular in classification. The import vector machine (IVM) has been introduced for its advantages over SMV. This paper tries to improve the IVM. The proposed method, which is referred to as the polychotomous machine (PM), uses the Newton-Raphson method to find estimates of coefficients, and the Rao and Wald tests, respectively, for addition and deletion of import points. Because the PM basically follows the same addition step and adopts the deletion step, it uses, typically, less import vectors than the IVM without loosing accuracy. Simulated and real data sets are used to illustrate the performance of the proposed method.

오리피스 튜브에 의한 단계별 냄새 분석용 희석가스의 제조방법에 관한 연구 (The Study on the Production Method of Stepwise Dilution Gas for Odor Analysis with Orifice Tubes)

  • 김한수;이석준;김선태
    • 대한환경공학회지
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    • 제35권2호
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    • pp.137-143
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    • 2013
  • 본 연구는 냄새 농도 평가를 위한 공기희석관능법의 단계별 희석가스 제조방법에 관한 것으로, 시료가스와 무취가스를 오리피스 튜브로 조절하여 희석하는 방법에 관한 것이다. 10배 및 30배 희석용 오리피스 튜브를 설계하고, 10, 30, 100, 300 및 1,000배 등의 단계별 희석가스를 10배 및 30배 희석용 오리피스 튜브를 반복적으로 사용하여 다양한 희석배율의 희석가스를 제조할 수 있다. 10배 희석용 오리피스 튜브의 홀 크기는 0.84 mm, 30배 희석용 오리피스 튜브의 홀 크기는 0.32 mm로 제작하였다. 제작된 냄새 평가를 위한 시료가스 희석용 오리피스 튜브에 의한 제조된 희석가스의 균질성은 2%RSD 내외로 우수한 재현성을 확인하였다. 또한, 기존 주사기를 이용하는 공기희석관능법에 의해 제조된 희석가스 농도와 비교하여 90% 이상의 상관성을 보이고 있었다. 진공펌프의 유량 변화에 따른 희석가스의 농도변화가 없이 간단히 진공흡인상자의 전단에 설치하여 활용할 수 있어 향후 다양한 현장 적용 평가 및 공기희석관능법과의 비교 연구를 통하여 현장에서의 복합악취 등의 평가에 활용할 수 있을 것으로 기대된다.

Synthesis and Photopolymerization of Photoreactive Mesogens Based on Chalcone

  • Nam, Sang-Woon;Kang, Suk-Hoon;Chang, Ji-Young
    • Macromolecular Research
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    • 제15권1호
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    • pp.74-81
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    • 2007
  • A series of photoreactive mesogens based on chalcone were prepared and their morphological behavior and reactivity were studied according to a variable number of alkyloxy tail carbons. The linear ester compounds 3a-h comprised two chalcone units connected to a benzene ring through ester linkages. All linear ester compounds showed enantiotropic liquid crystalline phases. The X-ray diffractograms for the mesophases of compounds 3a-h showed a set of reflections in the small-angle region which consisted of more than three sharp diffraction peaks with d spacings in the ratio of 1:1/2:1/3, confirming the well defined smectic A structures of the compounds. Compounds 3a-h were considered to be bifunctional monomers due to the presence of two photoreactive chalcone groups. Upon UV irradiation, its polymerization proceeded through the [2+2] addition reaction between chalcone units in a stepwise manner. An image pattern was obtained by the photopolymerization of the liquid crystal of the compound (3h) with decyloxy tails through a photomask. The irradiated part became dark while the masked part remained birefringent under polarized optical microscopy, which was ascribed to the production via the UV irradiation of a polymer or a dimer having cyclobutane rings by [2+2] addition, which thereby disrupted the alignment of the molecules.

A Mechanistic Study on Addition Reactions of Alicyclic Amines to 3-Butyn-2-one

  • 음익환;이정숙;육성민
    • Bulletin of the Korean Chemical Society
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    • 제19권7호
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    • pp.776-779
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    • 1998
  • Second-order rate constants have been measured spectrophotometrically for the addition reaction of a series of alicyclic amines to 3-butyn-2-one to yield their respective enamines at 25.0 'C. The reactivity of the amines increases with increasing the basicity of the amines. However, the Bronsted-type plot obtained exhibits a downward curvature as the basicity of the amines increases, i.e. βnuc decreases from 0.3 for low basic amines (pKa < 9) and to 0.1 for highly basic amines (pKa > 9). Such a curvature in the Bronsted-type plot is clearly indicative of a change in the reaction mechanism or transition state structure. From the corresponding reactions run in D2O, the magnitude of kinetic isotope effect (KIE) has been calculated to be about 0.8 for highly basic amines and 1.21 for weakly basic amines. The difference in the magnitude of KIE also supports a change in the reaction mechanism or transition state structure upon changing the basicity of the amines. Furthermore, the small KIE clearly suggests that H+ transfer is not involved in the rate-determining step, i.e. the addition reaction is considered to proceed via a stepwise mechanism in which the attack of the amines to the acetylene is the rate-determining step. The curvature in the Bronsted-type plot has been attributed to a change in the degree of bond formation between the amine and the acetylene.

석유탄화수소를 이용한 단세포단백질의 생산에 관한 연구 -IV. Candida tropicalis KIST 351의 연속배양 및 몇가지 조건에 관하여- (Production of Single Cell Protein on Petroleum Hydrocarbon -IV. On the Continuous Fermentation and Some Cultivation Conditions for Candida tropicalis KIST 351-)

  • 이용현;변유량;권태완
    • 한국식품과학회지
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    • 제4권3호
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    • pp.200-205
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    • 1972
  • Candida tropicalis KIST 351을 $2.5{\ell}$$28{\ell}$ 발효조에시 배양하여 석유 유분별자화능, 석유탄화수소기질의 즉차적 유가배양(流加培養), 폐배지(spent medium)의 재사용 및 연속배양 등 배양기술적인 기초문제를 검토한 바 그 개요는 다음과 같다. (1) 각종 경유유분(LGO, HGO, VGO, Diesel oil, SP(E), HGO-wax, L/M-wax)에 있어저 균체농도는 $11{\sim}15g/{\ell}$, 경유에 대한 수율은 $10{\sim}12%$, 소비된 n-paraffin에 대한 수율은 $77{\sim}82%$였다. (2) 동 균주를 유가배양 함으로써 균체들 배지에 대하여 $18.9g/{\ell}$, 경유에 대한 수율을 13%로 향상시킬 수 있었다. (3) 폐배지는 탄화수소를 유화시키고 증식을 촉친하는 효과를 가지고 있었으며 $Mg^{++}$를 보충하지 않었을 때는 20%, 보충하였을 때는 50%까지 회수 재 사용 할 수 있었다. (4) 균체생산을 위한 연속배양의 최적희석율은 $D=0.1{\sim}0.125\;hr^{-1}$의 범위내에 있으며, 이때의 균체농도는 약 $8g/{\ell}$였고, $D=0.125\;hr^{-1}$에서의 균체생산속도는 $1.0\;g/{\ell}/hr$로써 최대치에 달하였다. 소비된 경유 중의 n-paraffin에 대한 균체수율은 $D=0.1\;hr^{-1}$에서 0.94로써 최대치를 보였다. 그러나 희석율 $0.1\;hr^{-1}$에서 공급된 n-paraffin의 약 24%가 기질로써 소비 되지 않었으므로 이에 대한 적절한 대책이 요구된다.

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Type D 성격 유형이 관상동맥중재술 환자의 증상 경험과 삶의 질에 미치는 영향 (Influencing Effects of Type D Personality on Symptom Experiences and Quality of Life in Patients with Percutaneous Coronary Intervention)

  • 조은희;한순희;이명하;김성렬
    • 성인간호학회지
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    • 제28권5호
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    • pp.536-545
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    • 2016
  • Purpose: The aim of this study was to investigate the influencing effects of type D personality on symptom experiences and quality of life in percutaneous coronary intervention patients. Methods: A descriptive, cross-sectional study design was used. A total of 158 patients with percutaneous coronary intervention participated in this study, between July 1 and November 1, 2015. Data were analyzed by means, standard deviations, t-test, $x^2$ test, ANCOVA, and stepwise multiple regression analysis using SPSS 22.0 program. Results: About 53.8% of participants were classified as type D personality. The type D personality group reported statistically significantly higher symptom experience, lower cardiac function, and lower cardiovascular-specific quality of life compared to non-type D personality group. On stepwise multiple regression, the most significant factor of quality of life was symptom experiences (adjusted $R^2=.25$, p<.001), followed by type D personality (adjusted $R^2=.31$, p<.001). Conclusion: Personality trait assessment is recommended for patients with percutaneous coronary intervention to assess symptom experiences and quality of life. In addition, development of nursing intervention might be beneficial to manage symptom experience and quality of life in percutaneous coronary intervention patients with type D personality.

Kinetic Study on Michael-type Reactions of 1-Phenyl-2-propyn-1-one with Alicyclic Secondary Amines: Effect of Medium on Reactivity and Mechanism

  • Hwang, So-Jeong;Park, Youn-Min;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • 제29권10호
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    • pp.1911-1914
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    • 2008
  • Second-order rate constants (kN) have been measured for Michael-type addition reactions of a series of alicyclic secondary amines to 1-phenyl-2-propyn-1-one (2) in MeCN at 25.0 ${\pm}$ 0.1 ${^{\circ}C}$. All the amines studied are less reactive in MeCN than in $H_2O$ although they are more basic in the aprotic solvent by 7-9 p$K_a$ units. The Bronsted-type plot is linear with $\beta_{nuc}$ = 0.40, which is slightly larger than that reported previously for the corresponding reactions in $H_2O$ ($\beta_{nuc}$ = 0.27). Product analysis has shown that only E-isomer is produced. Kinetic isotope effect is absent for the reactions of 2 with morpholine and deuterated morpholine (i.e., $k^H/k^D$ = 1.0). Thus, the reaction has been concluded to proceed through a stepwise mechanism, in which proton transfer occurs after the rate-determining step. The reaction has been suggested to proceed through a tighter transition state in MeCN than in H2O on the basis of the larger $\beta_{nuc}$ in the aprotic solvent. The nature of the transition state has been proposed to be responsible for the decreased reactivity in the aprotic solvent.