• 약학회지
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• 제38권1호
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• pp.57-66
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• 1994

We studied the effect of eicosanoids on the content of energy metabolites and the intrasynaptosomal $Ca^{++}([Ca^{++}]_i)$ concentration in cerebral ischemic rats. An ischemic model was made by bilateral carotid artery ligation (BCAL) and by incubation of synaptosomes under aglycemic and $N_2$ gas bubbling condition. The content of ATP, creatine phosphate and glucose decreased at 15 minutes after BCAL while that of lactate increased in male Wistar rats. Oral administration of EPA(100 mg/ml/Kg/day) or DHA(16 mg/ml/Kg/day) for 6 weeks improved both the decreases and the increase of the cerebral energy metabolites. In addition, the increase of $[Ca^{++}]_i$, under BACL was suppressed by EPA or DHA treatment. When the both Wistar rats and SHR were administered orally with EPA or DHA for 6 weeks, the effect on the increase of $[Ca^{++}]_i$ under ischemia by $N_2$ gas bubbling were protected. From these results, it may be that EPA or DHA treatment were greatly contributed to preservation of ischemic cerebral energy metabolism and $Ca^{++}$ concentration.

• 분석과학
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• 제31권3호
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• pp.112-121
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• 2018

The hydrothermal carbonization method has received great attention because of the conversion process from biomass. The reaction produces various products in hydrochar, bio-liquid, and gas. Even though its yield cannot be ignored in amount, it is difficult to find research papers on bio-liquid generated from the hydrothermal carbonization reaction of biomass. In particular, the heterogeneity of feedstock composition may make the characterization of bio-liquid different and difficult. In this study, bio-liquid from the hydrothermal carbonization reaction of food wastes at $230^{\circ}C$ for 4 h was investigated. Among various products, fatty acid methyl esters were analyzed using two different extraction methods: liquid-liquid extraction and column chromatography. Different elutions with various solvents enabled us to categorize the various components. The eluents and fractions obtained from two different extraction methods were analyzed by gas chromatography with a mass spectrometer (GC/MS). The composition of the bio-liquid in each fraction was characterized, and seven fatty acid methyl esters were identified using the library installed in GC/MS device.

• BMB Reports
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• 제41권1호
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• pp.23-28
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• 2008

The altered amino acid (AA) levels as neurotransmitter closely correlate to neurodegenerative conditions including Alzheimer's disease (AD). Target profiling analysis of nineteen AAs in brain cortex samples from three Tg2576 mice as AD model and three littermate mice as control model was achieved as their N(O,S)-ethoxycarbonyl/tert-butyldimethylsilyl derivatives by gas chromatography. Subsequently, star pattern recognition analysis was performed on the brain AA levels of AD mice after normalization to the corresponding control median values. As compared to control mice, $\gamma$-aminobutyric acid among ten AAs found in brain samples was significantly reduced (P < 0.01) while leucine was significantly elevated (P < 0.02) in AD mice. The normalized AA levels of the three AD mice were transformed into distorted star patterns which was different from the decagonal shape of control median. The present method allowed visual discrimination of the three AD mice from the controls based on the ten normalized AA levels.

• 폴리머
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• 제24권5호
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• pp.621-628
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• 2000

폴리프로필렌 다공성 분리막은 산, 알칼리에 대한 내화학성이 좋고, 기계적 성질이 우수하며 높은 열적 안정성을 가지고 있으나, 막의 소수성 때문에 일부 영역에만 사용이 제한되고 있다. 따라서 본 연구에서는 소수성 막의 성능을 향상시키기 위해서 방사선 조사에 의한 그라프트 중합법을 사용하여, 친수성 작용기 (-COOH, -OH)를 갖는 acrylic acid (AAc)와 2-hydroxyethyl methacrylate (MEMA)를 도입하였다. 이때 반응시간, 반응온도, 조사량, 간의 첨가 효과, 팽윤현상에 의한 그라프트율의 변화를 조사하였다. 분리막의 기공크기를 분석하는 방법으로 행한 가스투과 실험에서 단량체의 종류와 관계없이 그라프트가 증가함에 따라 가스 투과속도가 감소함을 보였고, 오일 에멀젼 투과실험에서 미개질 폴리프로필렌 막의 오염현상은 크게 발생하였으나, 그라프트 중합 후, 높은 투과속도를 유지하여 막의 친수화 효과가 큰 것으로 나타났다.

• 폴리머
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• 제38권3호
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• pp.299-306
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• 2014

ZnO pillared saponite was synthesized via a microwave hydrolysis method. To enhance interfacial compatibility between zinc oxide (ZnO) pillared saponite and poly lactic acid (PLA), ZnO pillared organic saponite was prepared by intercalation modification of cetyltrimethylammonium bromide. Moreover, PLA/ZnO pillared organic saponite nanocomposites were prepared by melting processing. The microstructure analysis of PLA/ZnO pillared organic saponite nanocomposites showed that ZnO pillared organic saponite was exfoliated and homogeneouslydispersed in PLA matrix. The property results showed that ZnO pillared organic saponite improved the mechanical properties and thermal stabilities of PLA/ZnO pillared organic saponite nanocomposites. Differential scanning calorimetry (DSC) demonstrated that ZnO pillared organic saponite restrained the appearance of cold crystallization, lowered the glass transition temperature and melting temperature of PLA, and improved the crystallinity of PLA. The results demonstrated that ZnO pillared organic saponite had a good interfacial compatibility and heterogeneous nucleation effect in PLA matrix, and also played an active role in accelerating the crystallization process of PLA.

• 한국가스학회지
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• 제18권5호
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• pp.60-65
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• 2014

가연성 액체 혼합물의 화재 위험성을 특징짓는 주된 물리적 성질은 인화점이다. 본 연구는 이성분계 가연성 혼합물의 인화점을 측정하고 예측하고자 한다. Seta flash 밀폐식 장치를 이용하여 n-propanol+propionic acid 계의 인화점을 측정하였다. van Laar 식과 NRTL 식을 이용한 최적화 기법을 통해 인화점을 예측하였다. 이 계산치와 라울의 법칙에 의한 계산치를 비교하였다. 그 결과, 최적화 기법에 의한 계산치가 라울의 법칙에 의한 계산치 보다 측정값에 보다 근사하였다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.52-58
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• 2019

Marine emissions of Volatile Organic Compounds (VOCs) have received much attention because the International Maritime Organization (IMO) requires the installation of vapour emission control systems for the loading of crude oils or petroleum products onto ships. It was recently recognised that significant corrosion occurs inside these vapour emission control systems, which can cause severe clogging issues. In this study, we analysed the chemical composition of drain water sampled from currently operating systems to investigate the primary causes of corrosion in vapour recovery systems. Immersion and electrochemical tests were conducted under simulated conditions with various real drain water samples, and the impact of corrosion on the marine vapour recovery system was carefully investigated. Moreover, corrosion tests on alternative materials were conducted to begin identifying appropriate substitutes. Thermodynamic calculations showed the effects of environmental factors on the production of condensed sulphuric acid from VOC gas. A model of sulphuric acid formation and accumulation by the characteristics of VOC from crude oil and flue gas is suggested.

• Animal Bioscience
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• 제35권8호
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• pp.1195-1204
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• 2022

Objective: The objective of this study was to investigate the in vitro fermentation profiles of different soybean oligosaccharides (SBOs) and their effects on skatole production and cecal microbiota of broilers. Methods: Five SBOs with varying main component contents were fermented using an in vitro batch incubation inoculated with broiler cecal microbiota. Gas production was recorded automatically, skatole, indole and short-chain fatty acids (SCFAs) were determined using high-performance liquid chromatography, and microbial changes were analyzed using 16S DNA gene sequencing. Results: The addition of SBOs increased (p<0.05) gas production, suggesting bacterial growth-stimulating activities. In addition, the concentrations of indole were significantly (p<0.05) decreased after SBO supplementation, and SBO III, with higher sucrose and stachyose contents, decreased (p<0.05) the skatole level. Our results also revealed that the fermentation of SBOs by cecal microbiota produced (p<0.05) SCFAs, which were dominated by propionic acid, butyrate acid and lactic acid compared to the control. In addition, SBO III increased (p<0.05) the abundance of Firmicutes and Subdoligranulum and decreased that of Bacteroides. Conclusion: These results suggest that SBOs with higher sucrose and stachyose contents are promising prebiotics in modulating gut microbiota and reducing odor emission in broilers.

• 한국식품영양과학회지
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• 제5권1호
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• pp.61-64
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• 1976

P. edulis순(荀)의 free amino acid 및 organic acid의 종류(種類)와 함량(含量)을 측정(測定)한 결과(結果)는 다음과 같다. (1) Free amino acid는 18종(種)이 검출(檢出)되었는데, lysine histidine arginine tryptophan aspartic acid glutamic acid threonine serine proline glycine alanine valine methionine isoleucine leucine tyrosine phenylalanine 등 17종(種)이 정량(定量)되었으며 이들 중 serine이 가장 많았고, 1종(種)은 미확인(未確認)되었다. (2) Organic acid는 11종(種)이 검출(檢出)되었으며 이들 중 formic acid acetic acid oxalic acid maleic acid succinic acid fumaric acid citric acid tartaric acid sorbic acid 등 9종(種)이 확인(確認)되었고, 이들 중 oxalic acid가 가장 많아 291.14mg%이었으며, 2종(種)은 미확인(未確認)되었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2008년도 추계학술발표대회 및 제15회 신소재 심포지엄
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• pp.33.1-33.1
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• 2008