• 약학회지
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• 제35권4호
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• pp.332-334
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• 1991

The synthesis of melandrin has been accomplished in good yield by the reaction of 5-tosyloxyanthranilic acid ethyl ester with p-acetoxybenzoyl chloride, followed by removal of protecting groups with methanolic ammonia.

• 한국자기공명학회:학술대회논문집
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• 한국자기공명학회 1999년도 동계총회 및 제14회 자기공명 학술발표회
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• pp.4-5
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• 1999

• Archives of Pharmacal Research
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• 제16권1호
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• pp.1-5
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• 1993

The reaction of sulfhydryl groups in human serum ablumin with bacteriostatic and hypotensive notrosating agents such as sodium nitorprusside and sodium nitrite has been examined. The low reactivity of sodium nitroprusside to sulfhydral groups in albumin has been observed and the sterical inaccessilibility of the agent site which sulfhydryl group resides was implicated. The reaction of sodium nitrite with albumin was highly influenced by pH and little reactivity was observed at physiological pH. On the other hand, the reaction between albumin and S-nitrosoglutatione, an intermediate induced from the reaction of glutathione and nitrosating agents, resulted in the rapid decrease of free sulfhydryl groups in albumin. S-Nitrosylation of the sulfhydryl group by S-nitrosoglutathione and the subsequent production of mixed disulfide is the probable route of modification. In the physiological system, S-nitroso-glutathione may act as an active intermediate in expressing reacivity of nitrosating agents to sulfhydryl groups in albumin.

• 자원환경지질
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• 제26권3호
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• pp.421-429
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• 1993

Dissolution reactions of chemical grade zinc sulfide and natural sphalerite were studied in ferric chloride solution as an oxidant. To enhance the leaching reaction, ultrasonic technique was employed in this investigation. For the reaction with pure zinc sulfide, chemical reaction was the rate limiting step in the range of low conversion irrespective of applying ultrasonic wave. And the diffusion through liquid film instead of diffusion through product layer of free sulfur was the rate determining step because ultrasonic vibration removes the product from reaction zone. In the case of sphalerite with the ultrasonic vibrator, it was found that inert mineral layer diffusion was the rate determining step, in which the elemental sulfurs formed were removed by the ultrasonic action. Experimental results showed that the ultrasonic technique proved to be the methods which can significants improve the leaching performance.

• BMB Reports
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• 제33권4호
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• pp.353-357
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• 2000

A new assay method of ${\alpha}-Oxidase$ (fatty acid : oxygen dioxygenase, 1-decarboxylating) was developed using a bioluminescence reaction system of marine luminous bacterium, Photobacterium phosphoreum. ${\alpha}$-Oxidase was isolated from a cucumber (Cucumis sativus). Pentadecanoic acid was used as a substrate, and the product, tetradecanal, was analyzed with a bacterial luciferase-coupled reaction. Initial light intensity was directly related to the concentration of tetradecanal in the range of 1 nM to 10 ${\mu}M$. Optimal pH and temperature were 7.5 and $25^{\circ}C$, respectively. Optimal pentadecanoic acid concentration in a standard assay of ${\alpha}$-oxidase was 0.1 mM. The Km value of pentedecanoic acid was $85{\mu}M$. This method is straightforward, rapid, convenient, and easy. Its needs no treatment or extraction of reaction mixture.

• 대한기계학회논문집B
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• 제30권11호
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• pp.1123-1130
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• 2006

This study discusses about research efforts of hydrogen generation from hydrocarbon(e.g., diesel, gasoline, natural gas, and LPG), especially, butane reforming by using Autothermal Reforming Reaction (ATR) technology. Several catalysts were selected for butane ATR. Thermodynamic reactor conditions (temperature, $O_2$/C, S/C) are varied and reforming characteristics of 2 catalysts (Pt and Rh on ceramic supports) and 1 commercial catalyst (FCR-HC35) have been examined. To understand reaction behaviors in an ATR reactor comprehensively, temperature profiles of reactor were observed. By mass transfer limitation, fuel conversion decreases when GHSV increases. Significant temperature variation along the reactor was observed and it was mainly due reaction kinetics difference between exothermic oxidation and endothermic reforming reaction.

• 한국연소학회지
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• 제5권1호
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• pp.1-6
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• 2000

Surface reaction occurs at a certain surface temperature when a catalyst is heated up in a reactive mixture. If homogeneous ignition does not occur, a steady state is observed because the heat produced by the surface reaction is balanced with the heat loss caused by convection, conduction and radiation. The present paper treats the effects of pressure on the surface temperature at the steady state. Hydrogen and oxygen are used as reactants and nitrogen as an inert gas. A spherical platinum catalyst of 1.5 mm in diameter is sustained in the chamber with two wires of 0.1 mm in diameter. As results, there exists a maximum steady temperature at a certain relative hydrogen concentration which increases with total pressure. At the steady state, it can be approximated that the heat release is estimated by the mass transfer considering the effect of natural convection. The experimental results are explained qualitatively by the approximation.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.49-52
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• 2005

In this study, abiotic transformation of 1-naphthol via oxidative-coupling reaction was evaluated using Mn oxide which is ubiquitous in natural soils. The transformation of 1-naphthol catalyzed by synthetic birnessite $({\delta}-MnO_2)$ followed pseudo-lst order reaction, and the rate constants was in the range of $0.053{\sim}0.13\;min^{-1}$ with birnessite loadings of $12.5{\sim}50\;mg/20\;mL$. Since the oxidation of 1-naphthol was occurred on the reactive surface of the oxide particles, the rate constants with various birnessite loadings were correlated with birnessite surface area concentration. The correlation showed a strong linearity, which confirms the supposition of the surface reaction. From the correlation, therefore, the surface area normalized rate constant, $k_{surf}$, was determined to be 0.032 $L/m^2\;min$.

• Bulletin of the Korean Chemical Society
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• 제24권11호
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• pp.1618-1622
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• 2003

The photochemical reactions of methanolic nalidixic acid (NAL) solution in the absence and in the presence of air have been investigated using 300 nm UV light. From the reactions, 1-ethyl-7-methyl-4-oxo-4-hydro-1,8-naphthyridine (EMDN),formic acid, and formaldehyde are produced. In the presence of air, hydrogen peroxide is also detected along with the products listed above. The presence of oxygen during the irradiation of methanolic NAL solution effects on the product yield. The initial quantum yields of the products and of the NAL decomposition are determined. Possible reaction pathways for the photochemical reaction are suggested on the basis of the products analysis.

• 한국자동차공학회논문집
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• 제6권6호
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• pp.218-225
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• 1998

FTIR spectroscopy, useful technology for simultaneous and continuous measurement of the various components of the automotive exhaust gas, is utilized to investigate catalytic reaction charactristics of methane and a few unregulated exhaust emissions of NGV. Major findings are (1) catalytic reaction characteristics of methane measured in unsteady states of varying temperature are similar to those measured in steady states, (2) about 24 % of NO was oxidized to $NO_2$ as soon as they encounter catalysts, (3) study of formaldehyde suffers from difficulties in measurement due to the proximity in wavenumber of formaldehyde and methane, and requires an analyzer of higher resolution and accuracy than used in this study.