광화학 반응에서 생성된 Anthrasemiquinone Radical의 시간분해 ESR ; CIDEP에 관한 연구

홍대일,Hong Daeil,Kuwata Keiji 대한화학회 1990 대한화학회지 Vol.34 No.5

시간분해 ESR 분광법에서는 CIDEP법과 흡수 ESR 분광법을 사용하였다. 2-프로판올과 트리에틸아민 혼합용매에서 anthraquinone이 레이저 광선에 의해서 생성된 anthraquinone 라디칼 음이온을 시간분해 ESR 분광법으로 측정하였다. 이 semiquinone 라디칼은 대단히 안정하여 cw ESR을 측정할 수 있었다. 분극된 semiquinone 라디칼이 열적 평형상태로 소멸되는 속도상수는 스핀-격자 완화시간의 역수로서 2.6 ${\times}\;1-^5$ sec$^{-1}$이다. 그리고, 그 라디칼의 소멸속도상수는 300.0 sec$^{-1}$이다. CIDEP스펙트럼의 시간의존성에 대한 강도 변화는 마이크로파 출력이 강할수록 일반적으로 증가하였다. 그러나, 지나치게 출력을 높이면 감소 곡선상에 Torrey 진동이 뒷따라 일어났다. The time resolved electron spin resonance spectroscopy are used to two measurement methods of chemically induced dynamic electron polarization (CIDEP) and absorption ESR. The spectra of the semiquinone radical anion were successively detected in the laser flash photolysis of anthraquinone in the mixtures of 2-propanol and triethylamine. The semiquinone radical anion was fairly stable and its cw ESR could be observed. The rate constant (T1$^{-1}$) of the spin-depolarization of polarized semiquinone radical anion was 2.6 ${\times}\;1-^5$ sec$^{-1}$ and the decay of the radical anion was the first order with the rate constant (K$_1}$) of 300.0 sec$^{-1}$. The intensity of CIDEP spectra increased with the increasing the microwave power, but the Torrey wiggles appeared following with decay curves.

우리 농촌의 시급한 과제

홍대일 지역재단 2008 지역리더 Vol.1 No.-

고압에서 Dioxane-Water 혼합용매 중의 식초산의 전기전도

홍대일 啓明大學校 生活科學硏究所 1979 科學論集 Vol.5 No.-

The equivalent conductance of acetic acid has been measured at different pressures and temperatures, also with the solvent composition varied. With the increase of pressure, the conductance of acetic acid solution increased up to 20 dioxane weight percentage, at which level this value began to decrease above ??N acetic acid concentration. These phenomena indicate that the acetic acid molecules tend to dimerize at high pressure and concentration. The changes of activation energy for electrical conductance were dependent upon the change of pressure. Their values are shown the distribution from 3 to 6 Kcal/mole. The Shedlovskys equation served as the formula to calculate the ionization constants(Kd) of the solute from the conductivity data and physical properties of molecules in the solution. The Kd values of the solute were much lower than those of sodium chloride (7.8 at 100℃), which means that the hydration number was shown relatively small in change (1.5-2.5 at 20-40℃) compared with that of sodium chloride.

몇가지 할로겐化鹽의 진한 水溶液에 對한 電氣傳導度 測定

洪大一 대구보건대학 1973 대구보건대학 論文集 Vol.1 No.1

An investigation was made on the conductivities of the Ⅰ-Ⅰ valent and 2-Ⅰ valent halogen salts in aqueous solution, with particular emphasis on the effects of temperature, concentration and frequency of the solution in relation to the conductivity. It was fount that the conductivity of the halogensalts in highly concentrated aqueous solution follow Cube-Root-law better than the Deby-Hueckel theory. In the case of KCL, the conductivity temprerature. Polarization and Falkenhagen effect were most pronounced in the dilute solution while they diminished as the concen-tration increased. Activation energy was decreased as the concentration increased, and thece nergy of the 2-Ⅰ valent salts was higher than of the Ⅰ―Ⅰ valent salts. And it was noted that the larger the radius of the ien is the activation energy.

유기용매에서 Anthraquinone의 광반응에서 생성하는 짧은 수명의 반응중간체에 관한 시간분해 ESR 연구

홍대일,윤영현,손무정,김경찬,쿠와타 케이지,Hong, Daeil,Yun, Young Hyoun,Sohn, Moo-Jeong,Kim, Kyung-Chan,Kuwata, Keiji 대한화학회 1995 대한화학회지 Vol.39 No.4

Anthraquinone이 유기용매에서 광반으에 의하여 반응 중간체로 생성하는 짧은 수명의 중성 세미퀴논 라디칼과 음이온 라디칼을 시간분해 ESR법에 의하여 측정하였다. 2-2-propanol (PrOH)과 triethylamine (TEA) 10:1 혼합 용매에서 광반응에 의하여 생성하는 중성 anthrasemiquinone 라디칼(AQH${\cdot}$)과 음이온 라디칼 (AQH${\cdot}$)의 CIDEP 스펙트럼을 측정하였다. 생성한 AQH${\cdot}$은 반감기가 0.8 ${\mu}sec$로 수명이 아주 짧았으며, AQ${\cdot}$-은 안정하여 cwESR의 측정이 가능하였다. 스핀분극된 음이온 라디칼(AQ${\cdot}$-*)의 분극소멸 속도 상수는 $2.6{\times}10^5\; sec^{-1}$이고, 음이온 라디칼의 소멸은 1차 반응으로 속도상수가 $3.0{\times}10^2\; sec^{-1}$이다. 혼합용매에 TEA가 2% 미만일 때 CIDEP가 일어나지 않았다. 벤젠과 TEA 혼합용매에서는 반감기 3.0 ${\mu}sec$의 중성 anthrasemiquinone 라디칼의 CIDEP가 측정되었다. 그러나, cwESR은 측정되지 않았다. PrOH, TEA 또는 벤젠만의 용매로서는 CIDEP와 ESR을 측정할 수 없었다. The measurments of neutral semiquinone radicals, which were formed from the laser flash photolysis of anthraquinone (AQ) in the mixed solvents were carried out by the time resolved electron spin resonance (trESR) spectroscopy. The chemically induced dynamic electron polarization (CIDEP) spectra of the neutral semiquinone radical (AQH${\cdot}$) and semiquinone radical anion (AQ${\cdot}$-) were successively detected in the laser flash photolysis of AQ in the mixtures of 2-propanol (PrOH) and triethylamine (TEA). The neutral semiquinone radical was short-lived with the half-life of 0.8 ${\mu}sec$, whereas the semiquinone radical anion was relatively stable and then its cwESR could be observed. The rate constant of the spin-depolarization of semiquinone radical anion was $2.6{\times}10^5 sec^{-1}$ and the decay of the radical anion was the first order reaction with the rate constant of $3.0{\times}10^2\; sec^{-1}$. No CIDEP of semiquinone radical anion was observed in the mixture of PrOH and the lower concentration of TEA than 2 percent. The CIDEP spectrum of the neutral semiquinone radical was detected in the mixture of benzene and TEA with the half-life of 3.0 ${\mu}sec$. The neutral semiquinone radical could not be detected by cwESR. Neither CIDEP nor ESR absorption could be observed in PrOH, TEA or benzene only.

소화효소가 Helicobacter pylori의 증식과 공포화독소 생성에 미치는 영향

홍대식,강경희,장명웅 고신대학교(의대) 고신대학교 의과대학 학술지 2001 고신대학교 의과대학 학술지 Vol.16 No.1

Background : Global high prevalence rate of Helicobacter pylori infection is well-known fact. However, a large discrepancies exist between the diagnostic data obtained by the PCR and culture method, because the coccoid form of H.pylori which represent the majority form in the biological samples are not viable in the standard BHI broth with 5% horse serum. The component parts of saliva and gastric juice acted as neither stimulator nor inhibitor to the growth of H.pylori remain unclear. Objective : The purpose of this study was to evaluate the influence of amylase, pepsin, mucin, and lysozyme on the growth and vacuolating toxin production and titer of H.pylori in vitro. Materials and Methods : H.pylori 13,39,46,59,72,94,98 and 125 strains were isolated from patients with gastric disease. The digestive enzymes were inoculated in the 5% horse serum-BHI broth following final concentration of amylase (A; 0.20ug/ml), pepsin (P; 0.25ug/ml), mucin (M; 2,5ug/ml), and lysozyme (L; 1.5ug/ml). The vacuolating toxin titers of the culture supernatant were evaluated in the monolayer culture of RK-13 cells. Results : The morphologic conversion from bacillary to horse-shoe to coccoid forms of H.pylori was observed in the BHI broth containing 5% horse serum on day 5 culture. Half of H.pylori was changed from bacillary to coccoidal form on day 7 culture, most population of H.pylori was changed to coccoidal form on day 10 culture, and almost all H.pylori was changed to coccoidal form on day 14 culture. The growth of H.pylori 72, and 94 strains was increased in BHI broth containing each enzyme such as amylase, pepsin, mucin and mixture of two or three enzymes on day 5 and 7 culture. The growth of H.pylori 94 strains was increased in BHI broth containing each enzyme such as amylase, pepsin, mucin, and mixture of two or three enzymes on day 10 and 14 culture. The vacuolating toxin production of H.pylori strains was not influenced by the addition of amylase, pepsin, mucin, and lysozye or mixture of two or three enzymes. The neutralization of vacuolating toxin of H.pylori was not affected by the addition of amylase, pepsin, mucin, and lysozyme or mixture of two or three enzymes. Conclusion : We found that coccoid forms of H.pylori were viable in the standard 5% horse serum BHI media in the presence of amylase, pepsin, mucin, and lysozyme. The present study demonstrates that gastric juice of the stomach supports the viability of H.pylori and that oral route of infection is a plausible hypothesis. This work also demonstrates that gastric environment may not provide a selective advantage for the toxigenic strains of H.pylori.

ESR 分光法에 의한 Anthraquinone 置換體의 음이온 라디칼에 대한 超微細 分離常數의 測定과 理論的 解釋

洪大一,金庚燦,金昌鎭,李甲龍 대구효성가톨릭대학교 자연과학연구소 1994 基礎科學硏究論集 Vol.1994 No.1

Anthraquinone 치환제인 1,4-DHAQ, 1,5-DHAQ, 1,8-DHAQ 및 1,8-DCAQ 등을 2-propanol(PoOH)과 triethylamine(TEA)의 혼합용매에 녹여 레이저 광환원 반응에 의하여 생성되는 세미퀴논의 음이온 라디칼을 ESR 분광기로 측정하였다. 또한 이들 치환체 라디칼의 초미세 구조선으로부터 초미세 분리상수를 얻어, 그 값을 이용한 컴퓨터 모의실험에 의하여 초미세분리상수(hfsc)를 결정하였다. 뿐만 아니라 측정된 ESR 스펙트럼의 초미세 분리상수를 지정하기 위하여 EHMO법으로 π스핀밀도를 계산하였다. Substituted anthrasemiquinone radical anions, which were formed by laser flash photo-reduction of the substituted anthraquinone(1,4-DHAQ, 1,5-DHAQ, 1,8-DHAQ, 1,8-DCAQ), were studied by the electron spin resonance spectroscopy in the mixed solvents of the 2-propanol and the triethylamine. Hyperfine splitting constants (hfsc) were determined by simulating the ESR spectra. Extended Hu¨ckel Molecular Orbital(EHMO) calculations were performed to obtain π spin densities for these quinones. The hyperfine splitting constants could be assigned to specific protons on the basis of π spin densities.

상명대학교 공과대학 수학교육 강화방안 연구

홍대기(Hong, Dae-Ki),조태경(Cho Tae-kyung),박병수(Park Byoung-soo) 한국산학기술학회 2008 한국산학기술학회논문지 Vol.9 No.5

최근 국내대학 전반에 걸쳐서 공과대학의 우수 지원자가 점차로 감소되고 있는 상황이며 고등학교 수학 교육과정의 부실화에 따른 신입생의 학력저하에 대한 우려 또한 제기되고 있다. 이러한 위기상황에 대응하여 상명대학교에서는 공학교육의 발전 및 혁신을 위해 공학교육 혁신센터를 운영하고 있다. 공학교육 혁신센터는 공학교육 혁신을 위한 장가계획의 일환으로 수학 분야의 교육 강화를 위한 여러 가지 방안을 논의하여 노출하고 있다. 본 논문에서는 상명대학교에서 논의하여 도출한 수학 교육 강화방안을 제시한다. 이러한 결과들은 상명대학교 공과대학과 유사한 환경에 처해있는 다른 학교들의 수학 교육 강화를 위한 참고자료로 활용될 수 있을 것이다. Recently, the number of applicants for the engineering college is gradually decreased all over the nation. Additionally, the concerns of fall of freshman mathematical ability are raised due to the incomplete high school education. Therefore, the local universities endeavor in order to improve the quality of mathematics education, and study the countermeasure against the crisis. As part of these efforts, Sang-Myung University founds the innovation center for engineering education. The center derives several ideas in order to enhance the mathematics education quality. In this paper, the enhancement plans for the mathematics education in Sang-Myung University are proposed. Results in this paper will be helpful for other university to enhance the mathematics education as reference materials.

F⁰ , FeS 와 FeS₂ 에 의한 염소계 화합물의 환원적 분해반응

홍대일,김성국,현병욱,이병근,이갑두,박상원,차상은 대한환경공학회 2001 대한환경공학회 학술발표논문집 Vol.2001 No.12

ESR 분광법에 의한 Anthraquinone 치환체의 음이온 라디칼에 대한 초미세 분리상수의 측정과 이론적 해석

홍대일,김경찬,김창진,이갑룡,Hong, Dae Il,Kim, Gyeong Chan,Kim, Chang Jin,Lee, Gap Ryong 대한화학회 1994 대한화학회지 Vol.38 No.1

Anthraquinone 치환체인 1,4-DHAQ, 1,5-DHAQ, 1,8-DHAQ 및 1,8-DCAQ등을 2-propanol(PrOH)과 triethylamine(TEA)의 혼합용매에 녹여 레이저 광환원 반응에 의하여 생성되는 세미퀴논의 음이온 라디칼을 ESR분광기로 측정하였다. 또한 이들 치환체 라디칼의 초미세 구조선으로보터 초미세 분리상수를 얻어, 그 값을 이용한 컴퓨터 모의실험에 의하여 초미세분리상수(hfsc)를 결정하였다. 뿐만 아니라 측정된 ESR스펙트럼의 초미세 분리상수를 지정하기 위하여 EHMO법으로 $\pi$스핀밀도를 계산하였다. Substituted anthrasemiquinone radical anions, which were formed by laser flash photoreduction of the substituted anthraquinone (1,4-DHAQ, 1,5-DHAQ, 1,8-DHAQ, 1,8-DCAQ), were studied by the electron spin resonance spectroscopy in the mixed solvents of the 2-propanol and the triethylamine. Hyperfine splitting constants (hfsc) were determined by simulating the ESR spectra. Extended Huckel Molecular Orbital (EHMO) calculations were performed to obtain $\pi$ spin densities for these quinones. The hyperfine splitting constants could be assigned to specific protons on the basis of $\pi$ spin densities.