• 대한화학회지
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• 제25권1호
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• pp.44-49
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• 1981

Acetoacetanilide를 브롬화한 결과 예상한 ${\alpha}$-bromo 유도체가 얻어지지 않고, r-bromo 유도체가 얻어졌다. 이것을 mercaptoethanol과 반응시켜 sulfide 유도체를 만든다음, 산성하에서 고리화시킨 결과 2-(N-phenylcarbamoyl)methylene-1,4-oxathiane이 좋은 수율로 얻어졌다. 이 물질은 살균제 농약으로 널리 사용되고 있는 carboxin과 그 구조가 매우 유사하므로 이 물질의 biological activity는 흥미있는 과제가 될 것이다.

• Archives of Pharmacal Research
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• 제22권6호
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• pp.575-578
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• 1999

Derivatives of elema-1,3-diene were synthesized in several steps as polar analogs of $\beta$-elemene, antitumor agent under clinical phase. The lactone ring of compound 1 was opened by LiAlH4 to give diol 2 which was selectively protected by TBDPSCI. After acetylation of the secondary alcohol, the acetylated product was ozonolyzed and reduced to give elemene derivative 4 which was converted to diolefin 8 via selenides subsequent deprotection by tetrabutylammonium fluoride gave two compounds 9, 10.

• Bulletin of the Korean Chemical Society
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• 제15권11호
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• pp.1001-1003
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• 1994

A series of phosphodiesters of p-nitrophenyl phosphoryl derivatives were synthesized and used as a model substrate for phospholipase D (PLD). The phosphodiester substrates were synthesized from p-nitrophenyl phosphorodichloridate and corresponding alcohols with different chain lengths and polar groups. To measure the activity of PLD, either spectroscopic method for p-nitrophenol or pH-stat titration method was employed. For each substrate, effects of substrate concentration, pH, and $Ca^{2+}$ ion were examined. The kinetic parameters $V_{max}$ for the different substrates were varied depending on the chain lengths or charge of the alcohols. No calcium effect was observed in the hydrolysis of neutral and negatively charged alcohol derivatives, while positively charged choline derivative showed a strong $Ca^{2+}$ ion dependence.

• Korean Journal of Mathematics
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• 제30권2호
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• pp.199-203
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• 2022

Let f(z) be an entire function of exponential type τ such that ║f║ = 1. Also suppose, in addition, that f(z) ≠ 0 for ℑz > 0 and that $h_f(\frac{\pi}{2})=0$. Then, it was proved by Gardner and Govil [Proc. Amer. Math. Soc., 123(1995), 2757-2761] that for y = ℑz ≤ 0 $${\parallel}D_{\zeta}[f]{\parallel}{\leq}\frac{\tau}{2}({\mid}{\zeta}{\mid}+1)$$, where D_ζ[f] is referred to as polar derivative of entire function f(z) with respect to ζ. In this paper, we prove an inequality in the opposite direction and thereby obtain some known inequalities concerning polynomials and entire functions of exponential type.

• 전기화학회지
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• 제18권1호
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• pp.1-6
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• 2015

본 실험에서는 cyclic carbonate를 함유하는 styrene 유도체 VBCE를 Williamson 반응으로 합성하였으며 일반적인 조건에서 고분자중합까지 가능함을 보여주었다. 합성한 poly(VBCE)는 PEGMA와의 블렌드를 통하여 고분자전해질로 제조되었으며 이온전도도에 미치는 조성의 영향을 평가하였다. 흥미롭게도 poly(VBCE)의 함량이 0, 1.9, 5.8 mol%로 증가한 경우, 상온 이온전도도는 각각 $4.2{\times}10^{-5}$, $1.45{\times}10^{-5}$, $3.93{\times}10^{-6}S\;cm^{-1}$로 감소하는 경향을 보여주었다. DSC 측정결과, poly(VBCE)의 도입이 PEGMA의 $T_g$에 크게 영향을 주어 도입전 $-50^{\circ}C$에서 $-40^{\circ}C$, $-21^{\circ}C$로 각각 증가되는 현상을 관찰하였다. 이것은 극성 cyclic carbonate의 존재가 이온전도성 기질인 PEGMA의 유동성을 감소시키기 때문으로 이해할 수 있다. 따라서 cyclic carbonate를 고분자기질에 고정시키기 위해서는 기질의 움직임을 감소시키지 않는 분자설계가 필요할 것이다.

• Ocean and Polar Research
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• 제34권2호
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• pp.125-135
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• 2012

To evaluate the algicidal impact of a newly developed algicide thiazolidinedione derivative, TD49, on dinophyceae Akashiwo sanguinea in aquatic ecosystems, tentative culture experiments for the target species were conducted in small (SS), middle (MS), and large scale (LS) culture vessels. When TD49 was introduced at the final concentration of $2{\mu}M$ in SS and MS, as well as $1{\mu}M$ in LS, the abundance of A. sanguinea decreased significantly in all the treatments. On the other hand, total phytoplankton abundance, except A. sanguinea in the TD49 treatments, gradually increased with culture time, which implies that a cell destruction of A. sanguinea by TD49 is a major cause of the population growth by other phytoplankton species. Also, A. sanguinea was easily destroyed, which was likely to be a source of extracellular substances. In particular, a pH decrease was significant in the treatments than in the control, which indicates that the water in the treatments has been acidified, due to an increase in the heterotrophic metabolisms of bacteria and degradation of A. sanguinea cells. Our results indicate that the TD49 substance is the potential agents for the control of A. sanguinea in the enclosed and eutrophic water bodies.

• 대한화학회지
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• 제9권4호
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• pp.185-189
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• 1965

韓國産 酸性白土類 및 silica gel을 aniline yellow, o-nitro aniline, oil orange 色素 benzene 溶液과 작용시켜 非水溶液에서의 色素吸着率을 측정하였다. 그 吸着率은 silica gel이 酸性白土類보다 컸으며 酸性度에는 무관하였다. 또 上記 色素溶液에 각 10%의 添加溶劑 amine, alcohol, halogen類 化合物등을 加하여 高體酸의 色素吸着率의 변화(吸着阻害率)에 대하여 조사한 결과 위에 적은 順으로 그 영향이 적어지고, 同族體에서는 分子量이 적을 수록 그 영향이 커짐을 알았다. 따라서 非水溶液에서의 吸着은 amine基, 水酸基등과 같은 陰性基를 갖는 化合物은 選擇吸着하고 界面張力에 무관계하여 Traulbe系列의 逆轉現象을 나타내었다. 그 逆轉現象(吸着潮害現象)은 그 順位가 添加溶制의 雙極子能率과 대체적으로 일치하는 것으로 보아 固體酸模體인 活性硅酸과 被吸着體사이의 極盛的化學吸着에 의한 것이라 推定된다. 本實驗結果로부터 固體酸의 非水溶液에서의 吸着메카니즘, Traube 系列의 逆轉現象에 관하여 考察하게 되었다.

• Bulletin of the Korean Chemical Society
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• 제13권3호
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• pp.268-274
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• 1992

An attempt to improve the second harmonic generation (SHG) efficiency of MAP (methyl (2,4-dinitrophenyl)aminopropanoate) by modifying the substituents on the amino group of MAP is described. Several MAP analogues have been prepared using optically active amino acids alanine, phenylalanine and serine, and their SHG efficiencies measured. None of the MAP analogues exhibited SHG efficiencies as high as that of MAP. X-ray crystal structures of three MAP analogues have been determined. In the crystal structures of two of them, which were the derivatives of phenylalanine, two crystallographically-independent molecules existing in the asymmetric unit are aligned almost antiparallel. These structures are consistent with the very low SHG efficiencies of these compounds. On the other hand, the crystal structure of a serine derivative reveals substantial alignment of the dinitroaniline chromophore along the polar axis. However, the angle of 86.2° between the molecular charge tranfer axis and the polar axis of the crystal is still far away from the optimum value of 54.74° for the phase-matchable SHG. The structure is consistent with the SHG efficiency of this compound which is much higher than those of the phenylalanine derivatives but still lower than that of MAP. This study demonstrates the importance of the orientation of molecules in the crystal lattice in determining secod-order nonlinear optical properties of crystalline materials.

• KSBB Journal
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• 제26권4호
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• pp.323-327
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• 2011

The convenient derivatization method of chiral amino alcohols as 9-anthraldimine Schiff base derivatives for chiral resolution was developed and the liquid chromatographic enantiomer separation of chiral amino alcohols as 9-anthraldimine derivatives was investigated on several coated and covalently bonded polysaccharide-derived chiral stationary phases (CSPs). In general, the performance of Chiralcel OD-H (or Chiralcel OD) (${\alpha}$ = 1.24-2.89), the coated CSP derived from cellulose derivative was superior to the other CSPs for resolution of 9-anthraldimine derivatives of several amino alcohols. The results of enantioseparation depending on the structure of 9-anthraldimine analytes like the steric bulky group and the polar moiety etc were discussed. The analytical method was applied to measure the enantiomeric purity of commercially available chiral amino alcohols. It is expected that the convenient analytical method will be very efficient for determination of enantiomeric purity of amino alcohols as 9-anthraldimine Schiff base derivatives with strong UV absorption.

• Ocean and Polar Research
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• 제29권4호
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• pp.303-310
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• 2007

2-D wavelet analysis is applied to bathymetric data from the KR1 area of Korea Deepsea Mining Area. The wavelet analysis is one of the quantitative methods to analyze the topography. The wavelet allows us to create filters to select for topography in a continuous variety of shapes, sizes, and orientation. The 2-D Linear B-spline filter, 100 BS and 100 NF, is convolved with bathymetric data to identify the location of abyssal hills and abyssal troughs in bathymetry. In addition, the 2-D derivative of Cubic B-spline filter, 60 BS and 60 NF, is applied to bathymetric data to find the slope of abyssal hill in bathymetry. These filters were rotated $5^{\circ}$ counterclockwise from NS to match the dominant orientation of seafloor lineament. Both filters result in good match with abyssal hills, troughs, and slopes. This method can apply to fault, fold, and other lineament structures description with variable size. The result of application shows that wavelet analysis of bathymetric data could be used with fundamental data of geophysical analysis.