• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1977년도 추계학술발표회 및 특별 강연초록
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• pp.191-192
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• 1977

Microbial degradation of unnatural synthetic substances are interesting from hypothesis that a new metabolic pathway should be established from the unnatural compound to a common metabolic intermediate fro such an ability. The establishment of a new pathway essentially require a creature of new enzyme active on the unnatural synthetic compound which have never existed on the each.(중략)

• 한국응용과학기술학회지
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• 제33권3호
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• pp.492-497
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• 2016

The intermediate product resulting from the radical degradation experiment of PCE and the atomic charge gained through Gaussian03W were compared against each other. The result was that the ratio of PCE radical degradation was almost 98% or higher after the 9 hr point in reaction time. The reaction speed constant was $0.16hr^{-1}$ and it followed the first reaction. We could see that at each location of the PCE molecule, dechlorination happened at a point where the negative atomic charge was the greatest. Moreover, the intermediate product of PCE radical degradation that was confirmed in the experiment and literature coincided exactly with the intermediate product in the atomic charge calculation. Therefore, when the atomic charge is calculated, the radical degradation pathway of the organic chlorine compound could be forecast.

• Bulletin of the Korean Chemical Society
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• 제11권1호
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• pp.60-64
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• 1990

The reactions of alkanesulfonyl chlorides with pyridines in the presence of various solvents have been studied by means of kinetic method. Alkanesulfonyl chlorides bearing ${\alpha}$-hydrogen with the normal attack of pyridine is found to be at the ${\alpha}$-hydrogen with elimination to form the sulfene intermediate evidently. From the mass spectra by the reaction of ethanesulfonyl chloride with 3-picoline in the presence of methanol-$d_1$, it has shown that the reaction has a witness favorable to the slulfene intermediate.

• 한국세라믹학회지
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• 제45권11호
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• pp.725-733
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• 2008

In this study the preparation method of the spherical ADU droplets, intermediate compound of a HTGR nuclear fuel, was detailed-reviewed and then, the characteristics on an ageing and a washing steps among the wet process and the thermal treatment process on the died-ADU${\rightarrow}UO_3$ conversion with the high temperature furnaces were studied. The key parameters for spherical droplets forming are a precise control of feed rate and a suitable viscosity value selection of a broth solution. Also, a harmony of vibrating frequency and amplitude of a vibration dropping system are important factor. In our case, an uranium concentration is $0.5{\sim}0.7mol/l$, viscosity is $50{\sim}80$ centi-Poise, vibration frequency is about 100Hz. In thermal treatment for no crack spherical $UO_3$ particle, the heating rate in the calcination must be operated below $2^{\circ}C$/min, in air atmosphere.

• 생명과학회지
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• 제16권1호
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• pp.136-140
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• 2006

Ginseng was fermented by Aspergillus oryzae to search metabolites on the basis of increased biological activity and modified structure. From this research, two biotransformed compounds (WC2-2-1 and WC2-2-2) were detected and isolated through several chromatographic techniques. WC2-2-2 was confirmed to biologically active compound K by TLC, HPLC, and mass spectroscopy, while WC2-2-1 was going to be identified until now. In biological activity, both WG2-2-1 and WG2-2-2 exhibit the cytotoxicity on PC-3 cells, but WG2-2-2 was more active than WG2-2-1. It is supposed that WG2-2-1 is an intermediate metabolite transforming to final WG2-2-2, compound K.

• 약학회지
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• 제34권5호
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• pp.296-301
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• 1990

Irradiation of the berberinephenolbetaine in a stream of argon produced the 8,14-cycloberberines [1]. On treatment with ethylchloroformate $C_8-N$ bond cleavage of the compound [1] occurred, accompanied with dehydrochlorination to give 7-ethylcarboxyisoquinoline [3], and the product [3] treated with strong alkali solution to give the 13-oxonorotensane [4] in 64% yield. Irradiation of the compound [4] converted easily to dihydro-8H-dibenzo[a, g] quinolizine-8-one [5]. and then the compound [5] was treated with methyliodide to give the 8-oxo-quinolizinium methiode. The intermediate colume chromatography on IRA-400 afforded the benzo[c, g]azecine-5-one[6] in 63% yield. The results of biological activities for these compounds are also presented.

• KIEAE Journal
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• 제2권3호
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• pp.33-38
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• 2002

The intermediate range of temperatures($100{\sim}300^{\circ}C$) which can be achieved with CPCs(Compound Parabolic Concentrators) without tracking device provides both economic and thermal advantages for solar collector design. The present paper summarizes critical design considerations for CPC with cylindrical absorber and its optical performance using ray tracing program. Concentration ratios vary as acceptance half angle, ratio of reflector height to aperture width and ratio of reflector area to aperture area. This effects showed that the concentration ratio was increased as acceptance angle but optimum ratio of reflector height to aperture width existed at critical value. As a result of ray tracing, solar ray losses was maximized at acceptance half angle and this problem was solved by increasing absorber tube diameter. The concentrating flux distribution on the absorber surface was uniform but peak flux existed.

• 상하수도학회지
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• 제34권1호
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• pp.61-73
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• 2020

Tetracycline is one of the most commonly used antibiotics in domestic and foreign livestock industries to suppress the growth of pathogens. Tetracycline has been reported as a non-biodegradable compound. Therefore it has been not completely removed in the sewage treatment process. In this study, tetracycline was degraded using liquid ferrate (VI). Based on these experiments, the optimal water condition (pH and water temperature) were selected, appropriate liquid ferrate (VI) dosage was calculated, and finally the degradation pathway was estimated with the intermediate products detected by LC/MS/MS. All degradation experiments were completed within 30 seconds and the optimal condition was obtained in basic condition (pH 10) at room temperature (20℃). And the appropriate molar ratio between tetracycline and liquid ferrate (VI) was 12.5:1. Finally, 12 intermediate products were detected with LC/MS/MS and the degradation pathways and the degradation pathways and proposed the degradation pathways.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3690-3694
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• 2013

The $H_2Ge=Ge:$ and its derivatives ($X_2Ge=Ge:$, X = H, Me, F, Cl, Br, Ph, Ar${\ldots}{\ldots}$) is a new species. Its cycloaddition reactions is a new area for the study of germylene chemistry. The mechanism of the cycloaddition reaction between singlet state Cl2Ge=Ge: and formaldehyde has been investigated with CCSD(T)//MP2/$6-31G^*$ method. From the potential energy profile, it could be predicted that the reaction has only one dominant reaction pathway. The reaction rule presented is that the two reactants first form a fourmembered Ge-heterocyclic ring germylene through the [2+2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge: atom in the four-membered Ge-heterocyclic ring germylene and the ${\pi}$ orbital of formaldehyde forming a ${\pi}{\rightarrow}p$ donor-acceptor bond, the four-membered Ge-heterocyclic ring germylene further combines with formaldehyde to form an intermediate. Because the Ge: atom in intermediate hybridizes to an $sp^3$ hybrid orbital after transition state, then, intermediate isomerizes to a spiro-Ge-heterocyclic ring compound via a transition state. The research result indicates the laws of cycloaddition reaction between $H_2Ge=Ge:$ and formaldehyde, and laid the theory foundation of the cycloaddition reaction between $H_2Ge=Ge:$ and its derivatives ($X_2Ge=Ge:$, X = H, Me, F, Cl, Br, Ph, Ar${\ldots}{\ldots}$) and asymmetric ${\pi}$-bonded compounds, which is significant for the synthesis of small-ring and spiro-Ge-heterocyclic compounds. The study extends research area and enriches the research content of germylene chemistry.

• 생명과학회지
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• 제20권12호
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• pp.1906-1909
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• 2010

Benzenesulfinamide류의 가수분해반응에서 산 및 할라이드 이온의 촉매작용을 속도론적으로 조사하였다. 반응속도는 산 및 할라이드 이온의 농도가 증가함에 따라 증가하였고, benzenesulfinyl group에 전자주게기와 이탈기에 전자받게기를 가진 반응기질에서 빠르게 나타났다. 할라이드 이온의 반응성은 브롬 이온이 염소이온 보다 크게 나타남을 알 수 있었다. 반응 메카니즘은 초원가 중간체와 술포늄 양이온을 거쳐 진행 될 것으로 예상 할 수 있었다.