• 한국수소및신에너지학회논문집
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• 제19권5호
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• pp.430-438
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• 2008

Siberian spruce, found in the northern temperature and boreal regions of the earth, is usable biomass as fuels. In this study, parameters of thermochemical degradation by pyrolysis-liquefaction reaction of siberian spruce such as the effect of reaction temperature, reaction time and degradation products and energy yields were investigated. The liquid products from pyrolysis-liquefaction of siberian spruce contained various kinds of cyclicketones, cresols, dimethyl phenols and benzenediols. Combustion heating value of liquid products from pyrolysis-liquefaction conversion processes was in the range of $7,650{\sim}7,800cal/g$. The energy yield in pyrolysis-liquefaction of siberian spruce was as high as 69.5% after 40min of reaction at $400^{\circ}C$. The liquid products from the thermochemical conversion of siberian spruce could be used as high octane value fuels and fuel additives.

• 한국식품과학회지
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• 제20권3호
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• pp.453-458
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• 1988

식품의 가공, 저장 및 조리중 있어서 Maillard 반응으로 용이 하게 생성되는 Maillard 반응생성물과 비투석성 melanoidin의 아질산염 소거작용에 관하여 검토하였는데 그 결과를 요약하면 다음과 같다. 1. Maillard 반응생성물과 비투석성 melanoidin의 아질산염 소거능은 우수한 것으로 나타났다. 2. 반응용액의 pH변화에 따른 아질산염 소거능은 pH1.2에서 가장 켰으며 pH가 증가 할수록 아질산염 소거능은 감소하였다. 3. 환원능을 소실시키고 난 후의 아질산염 소거능은 pH1.2에서 1/2이하로 감소하였다. 4. Maillard반응생성물이 나타내는 아질산염 소거작용에는 melanoidin이 크게 관여하는 것으로 나타났다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.207-208
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• 2023

Concrete bricks and hollow concrete block products manufactured using ordinary portland cement react with salt and carbon dioxide absorbed from the soil and atmosphere in the use environment, causing contamination such as efflorescence. This is due to the reaction between calcium hydroxide, a cement hydration product, and carbon dioxide, producing and eluting calcium carbonate. This study was a preliminary study to compare and evaluate the reduction of efflorescence in concrete bricks and hollow concrete block products manufactured using carbon dioxide reaction hardening cement. The purpose was to evaluate the efflorescence occurrence in products using ordinary Portland cement.

• Applied Biological Chemistry
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• 제30권1호
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• pp.71-76
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• 1987

재래종 황색계자두 효소와 4종류의 polyphenol 화합물과 반응시켜 얻어진 효소적 갈변반응 생성물에 대하여 변이원성 및 변이원 억제작용에 관한 실험결과 B. subtilis H17과 M45 두 균주를 이용한 rec-assay에서 4종류의 갈변반응 생성물 모두 변이원성은 없었다. rec-assay에서 금속이온의 영향을 실험한 결과 pyrogallol의 갈변반응 생성물의 경우 $Fe^{3+},\;Mn^{2+},\;Zn^{2+},\;Ni^{2+}\;Al^{2+}$에서 약한 영향을 받았으며 hydroxyhydroquinone의 갈변반응 생성물에서는 $Cu^{2+},\;Pb^{2+}$, 그리고 catechol의 갈변반응 생성물에서는 $Mn^{2+}$ 공존하에서 약한 영향을 받았다. DNA절단실험 결과 갈변반응 생성물 자체에 의해서는 4종류의 시료 모두 DNA절단능력은 없었다. 금속이온의 영향에서는 $Fe^{2+}$의 경우 그 자체에 의해 절단되었으며 $Cu^{2+}$은 DNA 절단을 촉진하는 것으로 나타났다. S-9 mix를 첨가한 돌연변이 유발실험에서는 4종류의 갈변반응 생성물 모두 농도증가에도 변이원성은 없었으며 변이원 물질인 $benzo\;{\alpha}\;pyrene$에 대한 돌연변이원 억제반응에서는 4종류의 갈변반응 생성물 모두 농도증가에 따라 대조구에 비해 강한 억제작용을 나타냈다. 따라서 재래종 황색계 자두로부터 추출한 polyphenol oxidase와 4종류의 polyphenol 화합물과 반응시켜 얻어진 효소적 갈변반응 생성물의 들연변이원성 실험결과 갈변반응 생성물자체에 의한 돌연변이원성은 없었으며 금속이온의 영향도 받지 않는 것으로 나타났으나 강력한 발암물질인 $benzo\;{\alpha}\;pyrene$을 사용한 돌연변이 억제실험에서는 4종류의 갈변반응 생성물 모두 강한 돌연변이 억제작용이 있음을 알 수 있었다.

• 한국식품과학회지
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• 제19권3호
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• pp.212-219
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• 1987

재래종 적색 자두 (Prunus salicina)에서 효소를 추출하여 4종류의 polyphenol화합물과 반응시켜 얻어진 갈변반응 생성물에 대하여 Bacillus subtilis H17과 M45를 이용한 rec-assay와 Salmonella typhimurium TA98과 TA100 두 균주를 이용한 Ames test, 그리고 calfcthymus DNA를 이용하는 DNA절단시험을 이용하여 돌연변이원성과 돌연변이 억제작용을 조사하였다. 포자 rec-assay 에서는 pyrogallol, hydroxyhydroquinone, 3,4-dihydroxytoluene, chlorogenic acid 의 갈변반응 생성물은 모두 DNA손상능력이 없었으며 8가지 금속이온 중 ${Zn}^{2+}$과 ${Ni}^{2+}$의 첨가로 고초균 DNA손상에 약한 영향을 나타내었다. DNA절단시험 결과 4종류 갈변반응 생성물 모두 DNA절단작용이 없었으며 금속이온의 영향에 있어서는 pyrogallol 갈변반응 생성물이 ${Cu}^{2+}$의 영향을 받아 ${Cu}^{2+}$의 농도가 증가함에 따라 강한 절단작용을 나타내었으며 3,4-dihydroxytoluene 과 hydroxyhydroquinone갈변반응 생성물은 금속이온의 영향을 전혀 받지 않았다. 또한 chlorogenic acid갈변반응 생성물은 DNA 절단을 억제하는 효과를 나타내었다. Ames test에서는 4가지 갈변반응 생성물 모두 변이원성은 없었으며 benzo$[{\alpha}]$pyrene을 사용한 변이원성 억제작용 실험결과 benzo$[{\alpha}]$pyrene의 활성을 강하게 억제하는 것으로 나타났다.

• 한국수소및신에너지학회논문집
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• 제16권2호
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• pp.159-169
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• 2005

Cellulose, consisted of 45 wt% in wood, is usable as fuels and heavy oil additives if depolymerized to monomer unit, because the chemical structures are similar to high octane materials found in gasoline. In this study, thermochemical degradation by solvolysis reaction of cellulose such as the effect of reaction temperature, reaction time and type of solvent on conversion yield and degradation products were investigated. It was found that the effectiveness of the solvent on the sovolysis reaction was as follows; acetone>n-butanol>tetralin. When acetone was used as a solvent, the highest cellulose conversion was observed to be 91.8% at 500$^{\circ}C$, 40min. Combustion heating value of liquid products from thermochemical conversion processes was in the range of 7,330${\sim}$7,410cal/g. The energy yield and mass yield in acetone-solvolysis of cellulose was as high as 66.8% and 37.0 g oil/100g raw material after 40min of reaction at 400$^{\circ}C$. Various aliphatic and aromatic compounds were detected in the cellulose solvolysis products. The major components of the solvolysis products, that could be used as fuel, were mesityl oxide, mesitylene, isophorone.

• 한국수소및신에너지학회논문집
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• 제18권1호
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• pp.85-94
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• 2007

Rice straw, produced as an agricultural by-product, is usable biomass as fuels if depolymerized to monomer unit, because the chemical structure are similar to high octane materials found in gasoline. In this study, parameters of thermochemical degradation by solvolysis reaction of rice straw such as the effect of reaction temperature, reaction time and type of solvent on conversion yield and degradation products were investigated. It was found that the effectiveness of the solvent on the solvolysis reaction was as follows; acetone>cresol>butanol. When acetone was used as a solvent, the highest rice straw conversion was observed to be 91.5% at $500^{\circ}C$, 40 min. Combustion heating value of liquid products from thermochemical conversion processes was in the range of 7,380 cal/g. The energy yield and mass yield in acetone-solvolysis of rice straw was as high as 69.0% and 38.2 g-oil/100g-raw material after 40 min of reaction at $350^{\circ}C$. Various aliphatic and aromatic compounds were detected in the rice straw solvolysis products. The major components of the solvolysis products, that could be used as fuel, were 4-methyl-2-pentanone, 3,5,5-trimethyl-2-cyclopentan-1-one as ketones.

• 한국식품영양과학회지
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• 제33권6호
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• pp.1013-1016
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• 2004

토란으로부터 polyphenol oxidase를 추출하여 Maillard reation products(MRPs)가 토란 PPO에 미치는 영향을 조사하였다. 토란 PPO에 대한 MRPs의 저해 효과는 사용한 기질이 (+)-catechin, catechol인 경우에 높게 나타났다. 그리고 MRPs의 토란 PPO 저해 효과는 당의 종류를 달리하여 생성한 MRPs 중에서 fructose와 glucose로 제조한 MRPs의 첨가시 가장 높았으며, glycine과 glucose의 농도가 높아질수록 저해 효과가 증가하였다. 반응 시간에 따른 MRPs의 저해 효과를 조사한 결과, 반응 시간이 길어질수록 MRPs의 변색 정도가 높아졌으며, 이에 따라서 토란 PPO에 대한 저해 효과도 증가하였다.

• Food Science and Biotechnology
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• 제14권1호
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• pp.152-163
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• 2005

Lipid peroxidation is a primary cause of quality deterioration in meat and meat products. Free radical chain reaction is the mechanism of lipid peroxidation and reactive oxygen species (ROS) such as hydroxyl radical and hydroperoxyl radical are the major initiators of the chain reaction. Lipid peroxyl radical and alkoxyl radical formed from the initial reactions are also capable of abstracting a hydrogen atom from lipid molecules to initiate the chain reaction and propagating the chain reaction. Much attention has been paid to the role of iron as a primary catalyst of lipid peroxidation. Especially, heme proteins such as myoglobin and hemoglobin and "free" iron have been regarded as major catalysts for initiation, and iron-oxygen complexes (ferryl and perferryl radical) are even considered as initiators of lipid peroxidation in meat and meat products. Yet, which iron type and how iron is involved in lipid peroxidation in meat are still debatable. This review is focused on the potential roles of ROS and iron as primary initiators and a major catalyst, respectively, on the development of lipid peroxidation in meat and meat products. Effects of various other factors such as meat species, muscle type, fat content, oxygen availability, cooking, storage temperature, the presence of salt that affect lipid peroxidation in meat and meat products are also discussed.

• 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.