금합금계 매몰재의 Cristobalite와 Quartz 첨가량에 따른 열팽창과 압축강도 변화

한만소,Man-So Han 배재대학교 공학연구소 2004 공학논문집 Vol.6 No.2

금합금계 매몰재 재료의 물리적 특성은 각각 열팽창계수과 압축강도, 입도 분포에 크게 좌우된다. 일반적으로 금합금계 매몰재는 cristobalite와 quartz, plaster로 주성분을 구성하고 있다. 그리고 cristobalite와 quartz의 열팽창계수는 $2.6\times10^{-6}/^\circC$, $2.32\times10^{-6}/^\circC$, 로 이 두 재료의 혼합비가 매몰재의 열팽창 계수를 변화시키는 매우 중요한 역할을 하고 있다. 현재 국내에서는 금합금계 매몰재는 전량 수입에 의존하고 있고 그 시장 수요 또한 대단히 크다. 따라서 균일한 입도 분포를 가지는 cristobalite와 quartz의 개발과 주조금속의 열팽창과 냉각에 따른 수축력을 고려한 열팽창계수를 가지면서 매몰재의 요구강도에 적합한 압축강도를 가지는 금합금계 매몰재의 개발이 필수적이다. 따라서 본 연구에서는 먼저 균일한 입도를 갖는 cristobalite와 quartz 분체의 제조와 cristobalite와 quartz의 혼합비에 따른 열팽창계수와 압축강도를 비교 분석하였다. 본 연구의 결과로 표면이 매끄럽고 균일한 입도 분포를 갖는 cristobalite와 quartz를 제조하였으며, cristobalite와 quartz의 혼합비가 45:25가 열팽창계수와 압축강도에서 매몰재가 요구하는 조건을 만족하였다. The physical properties of gold investment materials are depending on it's thermal expansion coefficients, compressive strength, and particles size distributions. Normally the gold investment materials are consisted of cristobalite, quartz and plaster. Since the thermal expansion coefficient of cristobalite and quartz are $2.6\times10^{-6}/^\circC$, $2.32\times10^{-6}/^\circC$, respectively, the composition ratio of each components influence the thermal and clinical properties of gold investment materials. Recently are imported from overseas and the commercial market is expected to expand. Thus it is necessary to develop the optimum strength and compressive strength of gold investment materials which the an homogeneous size distribution and thermal expansion coefficients. Therefore two different experiments has been done. Firstly the homogeneous cristobalite and quartz are made by pulverizing milling. Secondly the compressive strength and thermal expansion coefficients are analysed by the composition ratio of cristobalite and quartz. As a results of experiments, homogeneous distribution of cristobalite and quartz are observed by pulverizing and milling. The optimum compressive strength was obtained at the ratio of 45:25 cristobalite, quartz respectively.

고상법에 의한 Dermorphin 유사체의 합성과 생물학적 활성에 관한 연구

한만소 ( Man So Han ) 한국유화학회 2002 한국응용과학기술학회지 Vol.19 No.4

N/A Dermorphin is a hepta peptide(H-Tyr-DAla-Phe-Gly-Tyr-Pro-Ser-NH_2) with exceptionally potent and long-lasting peripheral and central activity. Dermorphin analogues, dermorphionyl(DMP)-Lys-NH_2 and DMP-Lys-Lys-NII_2 have been prepared in order to examine the effect of opiod activity. Dermorphin analogues were synthesized by the solid phase method. The crude peptide was purified by gel filter on a Sephadex LH-20, characterized with HPLC and amino acid analyzer. Analgesic potency was estimated by writhing syndrome method and Randall-Selitto method. As a result, dennorphin analogues have lower potency than that of morphine.

벤조페논 유도체의 합성과 전기화학 및 분광학특성에 관한 연구

한만소(Man So Han),채원석(Won Seok Chae) 한국유화학회 2008 한국응용과학기술학회지 Vol.26 No.2

The benzophenone derivatives(4-CH₃O-4 -NO₂ and 3,4 -di-NO₂) are synthesized by the Fridel-Craft acylation and the nitration method. Electrochemical redox potentials of the benzophenone derivatives (4-CH₃O, H, 3-Cl, 3-NO₂, 4-NO₂, 4-CH₃O-4 -NO₂, 3,4 -di-NO₂) are measured by using cyclic voltammometry. In the relationship of summing Hammett value and redox potential, we find a proportional constant(ρ) that shows a good relation with an electrochemical property and a reactivity of the benzophenone derivatives. The benzophenone substituted with the electron donating groups(4-OCH₃ and 4-OCH₃-4 -NO₂) are higher the energy in the LUMO level, then increasing a band-gap energy(Eg), their Egs are obtained as a 3.94 eV and 3.59 eV, respectively.

S-Phenyl-S-vinyl-N-p-tosylsulfilimine 유도체에 대한 Thioglycolic Acid의 친핵성 첨가반응에 관한 반응속도론적 연구

김태린,한만소,편상용,Kim, Tae Rin,Han, Man So,Pyun, Sang Yong 대한화학회 1996 대한화학회지 Vol.40 No.10

Vinylsulfilimine(VSI) 유도체($p-OCH_3$, H, p-Cl 및 p-Br)에 대한 thioglycolic acid의 친핵성 첨가반응속도를 자외선 분광법으로 측정하여 넓은 pH 범위에서 적용될 수 있는 속도식을 구하였다. pH에 따른 속도상수의 변화, general base 및 치환기 효과 등을 바탕으로 반응 메카니즘을 제안하였다. 즉 pH3.0 이하에서는 sulfilimine의 질소에 양성자가 먼저 첨가된 다음 중성 thioglycolic acid 분자가 탄소 이중결합에 첨가되고, pH 3.0-9.0 영역에서 thioglycolic acid의 중성분자와 음이온의 첨가가 경쟁적으로 일어나며, pH 9.0 이상에서는 황화 음이온이 첨가되는 전형적인 Michael type의 반응이 진행됨을 알았다. The rate constants for the nucleophilic addition reactions of thioglycolic acid to vinylsulfilimine(VSI) derivatives(p-OCH3, H, p-Cl and p-Br) were determined by an ultraviolet spectrophotometric method, and rate equations which can be applied over a wide pH range were obtained. On the basis of rate equation, general base catalysis and substituent effect, a plausible addition reaction mechanism was proposed: Below pH 3.0, the reaction was proceeded via the addition of neutral molecule to carbon-carbon double bond after protonation at the nitrogen atom of the sulfilimine, and in the pH range of 3.0 to 9.0, the neutral molecule and its anion attacked to carbon-carbon double bond competitively. Above pH 9.0, sulfide anion added to the double bond (Michael type addition).

Al(lll)-Porphyrin착물에 의한 올레핀 산화반응 메카니즘 연구

나훈길,한만소,Na, Hun-Gil,Han, Man-So 대한화학회 2006 대한화학회지 Vol.50 No.1

착물을 촉매제로 하여 용매인 CH2Cl2와 산화제 NaClO를 사용하여 올레핀 산화반응의 메카니즘 연구를 하였다. 이들 반응에서 포르피린의 치환기는 TPP(5,10,15,20-Tetraphenylporphyrin)와 (p-X)TPP(X=CH3O, CH3, F, Cl)를, 올레핀은 styrene과 (p-X)styrene (X=CH3O, CH3, Cl, Br)을 사용하였다. 일반 효소반응에서 잘 알려진 Michaelis-Menten식에 따라 Km과 Vmax 값을 구하였다. Michaelis-Menten 식의 속도 파라미터를 포르피린 치환기에 따라 측정하고, 이들 파라미터와 치환기상수 간의 상관성을 조사함으로써 올레핀 산화반응의 중간체 M-oxo-olefin의 형성 과정과 분해 과정이 촉매활성이나 속도 결정 단계의 변화에 미치는 영향을 분석 하고자 하였다. studies of olefin oxidation using Al(III)-porphyrin complexes as catalyst are investigated in CH2Cl2, in which NaClO is used as terminal oxidant. Porphyrins are TPP(5,10,15,20-Tetraphenylporphyrin) and (p-X)TPP(X=CH3O, CH3, F, Cl). Olefins are styrene and (p-X)styrene (X=CH3O, CH3, Cl, Br). The values of Km and Vmax are calculated from the Michaelis-Menten equation. According to the substituents of substrate and catalyst, kinetic parameters will be measured. Investigating the correlation between the Michaelis-Menten rate parameters and the substituent constants, we were able to analyze the influence on the changes of catalytic activity or the rate determining step during the process of the formation and the dissociation of the M-oxo-olefin.

주조에 의한 Core와 CAD-CAM에 의한 Core의 적합도 비교평가

김기백 ( Man So Han ),한만소 ( Ki Baek Kim ) 한국치위생과학회 2012 치위생과학회지 Vol.12 No.4

Dental CAD (computer-aided design)/CAM (computer-aided manufacturing) systems facilitate the use of zirconia core for all-ceramic crown. The purpose of this study was to evaluate the marginal and internal fit of zirconia core fabricated using a dental CAD/CAM system and to compare the fit of metal cores by a conventional method. Ten identical cases of single coping study models (abutment of teeth 11) were manufactured and scanned. Ten zirconia cores were fabricated using dental CAD/CAM system. An experienced dental technician fabricated 10 samples of metal cores for the control group using the lost wax technique. Marginal and internal fit was measured by the silicone replica technique. Fit was measured with magnification of 160 using a digital Microscope. Margin, rounded chamfer, axial wall and incisal fits were measured for comparison. T-test of independent sample for statistical analysis was executed with SPSS 12.0 for Windows (SPSS Inc., Chicago, IL, USA) (a=0.05). The mean (SD) for marginal, rounded chamfer, axial wall and incisal were: 97.0 (25.3) mm, 104.0 (22.0) mm, 59.6 (21.4) mm and 124.8 (33.3) mm for the zirconia core group, and 78.2 (18.4) mm, 83.8 (15.1) mm, 42.7 (9.6) mm and 83.4 (14.4) mm for the metal core group. T-test showed significant differences between groups for margin (p<.001), rounded chamfer (p<.001), axial wall (p<.001) and incisal (p<.001). But zirconia core group observed that the marginal and internal fit values in the present study were within clinically acceptable range.

2-Phenyl-4H,5H-3-methyl-3-thiazolinium Perchlorate 유도체의 가수분해 반응 메카니즘에 관한 반응속도론적 연구

김태린,이소영,한만소,변상용,이석희,Kim, Tae-Rin,Lee, So-Young,Han, Man-So,Pyun, Sang-Yong,Lee, Seok-Hee 대한화학회 2000 대한화학회지 Vol.44 No.2

2-PhenyI-4H,5H-3-methyl-3-thiazolinium perchlorate(PTP)유도체들의 가수분해속도상수를 수용액에서 자외선 분광법으로 측정하여 넓은 pH 범위에서 적용될 수 있는 속도식을 구하였다. pH에 따른 속도상수의 변화, 가수분해 생성물의 확인, 일반염기 및 치환기 효과 등을 바탕으로 반응 메카니즘을 제안하였다. 즉 pH 4.0 이하에서는 물분자의 첨가가 일어나 가수분해가 진행되며, pH 9.0 이상에서는 전형적인 Michael type의 반응이 일어나며, pH $4.5{\sim}8.0$ 사이에서는 이들 두 반응이 경쟁적으로 일어남을 알았다. The rate constants for the hydrolysis of 2-phenyl-4H,5H-3-methyl-3-thiazolinium perchlorate(PTP) derivatives were detemined by the use of ultraviolet visible spectrophotometer in water. The rate equations which could be applied over a wide pH ranges were obtained. On the basis of rate equation, hydrolysis product analysis, general base catalysis, and substituent effect, a plausible mechanism of the hydrolysis is proposed: Below pH 4.0, the reaction is initiated by addition of water, while above pH 9.0, Michael type nucleophilic addition takes place. In the pH range of $4.5{\sim}8.0$, these two reactions appear to occur competitively.

R₂NH/R₂NH₂⁺-20 mol% DMSO(aq)의 조건에서 2,4-dinitrophenyl 5-substituted-2-furoates의 아실 이동반응에 대한 반응속도론적 연구. 반응 메커니즘에 미치는 비이탈기와 이탈기의 효과

변상용,백규철,한만소,조봉래,Sang Yong Pyun,Kyu Cheol Paik,Man So Han,Bong Rae Cho 대한화학회 2023 대한화학회지 Vol.67 No.3

Acyl transfer reactions of 2,4-dinitrophenyl-5-substituted-2-furoates (1a-d) promoted by R₂NH/R₂NH₂⁺ in 20mol% DMSO(aq) have been studied kinetically. The reactions are second-order and exhibit downward curves of the Brönsted plots with pK_a⁰ = 9.5, β₁ = 0.23-0.35 and β₂ = 0.88-0.99. The k₁ values increased with a stronger nucleophile and as the electron-withdrawing ability of the 5-furyl substituent increases. In contrast, the k₂/k_-1 values were nearly idential regardless of the 5-furyl substituents. From these results, a stepwise mechanism with a change in the rate-determining step(RDS) is proposed.

${\alpha}$,N-Diphenylnitrone 유도체에 대한 Cysteine 및 Thiophenol의 친핵성 첨가물에 관한 연구

김태린,변상용,한만소,이광일,Tae-Rin Kim,Sang-Yong Pyun,Man-So Han,Kwang-Il Lee 대한화학회 1991 대한화학회지 Vol.35 No.3

${\alpha}$,N-diphenylnitrone에 cysteine과 thiophenol을 반응시켜 4개의 thiazolidine과 다음의 5가지 새로운 화합물을 합성하였다. ${\alpha}$,thiophenoxy-benzylidene aniline : ${\alpha}$, thiophenoxy-p-hydroxybenzylidene aniline : ${\alpha}$,thiophenoxy-p-chlorobenzylidene aniline : ${\alpha}$,thiophenoxy-p-methoxybenzylidene aniline : ${\alpha}$,thiophenoxy-p-nitrobenzylidene aniline. 이 화합물들의 구조는 원소분석, UV-, IR 및 NMR- 스펙트럼에 의해 확인하였다. Four thiazolidines and following five new compounds were prepared by the addition reaction of cysteine and thiophenol to ${\alpha}$,N-diphenylnitrones, respectively ; ${\alpha}$,thiophenoxy-benzylidene aniline ;${\alpha}$,thiophenoxy-p-hydroxybenzylidene aniline ; ${\alpha}$,thiophenoxy-p-chlorobenzylidene aniline ;${\alpha}$,thiophenoxy-p-methoxybenzylidene aniline ; ${\alpha}$,thiophenoxy-p-nitrobenzylidene aniline. The structure of these compounds were confirmed by the elemental analysis, UV-, IR-and NMR-spectra.

CAD/CAM 세라믹의 두께가 색조에 미치는 영향

강월 ( Wol Kang ),한만소 ( Man-so Han ),김지환 ( Ji-hwan Kim ) 한국치위생학회(구 한국치위생교육학회) 2016 한국치위생학회지 Vol.16 No.5

Objectives: The purpose of the study was to investigate the effect of CAD/CAM ceramic thickness on shade. Methods: 24 disk-shaped ceramic specimens (E.Max CAD & Empress CAD, 12 mm × 12 mm) were prepared and divided into 4 groups (n=6). Ceramic specimens in 2 thicknesses (0.8 mm, 1.0 mm) were made low translucency(LT) shade A2. All specimens were measured as L*, a*, b* using spectrophotometer. The color differences(ΔE values) between the specimen and a control target block (12 × 12 × 1.2 mm) were calculated. Two-way ANOVA performed between 2 groups(material and thickness). Results: As the thickness increased, the L* (for all groups) and b* value (for all groups) increased and the a* value(for LR group) decreased. The mean color differences caused by thickness was acceptible (ΔE > 2) for group LD1. But the mean color differences by thickness were not selected (ΔE < 2) for group LD2, LR1, LR2. Conclusions: The different thickness can influence the final color of CAD/CAM ceramic.