• 한국연초학회지
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• 제31권2호
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• pp.85-94
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• 2009

This work has been conducted to develop a method for the analysis of neutral volatile flavors and their precursors in tobacco. The neutral volatile compounds and precursors in tobaccos have been investigated by Neutral Volatile scan method(NV scan) using Soxhlet extractor. The method has been used to analyze a range of different tobaccos and tobacco products. Neutral flavor compounds were classified as three sections(1st Volatile Fraction, Breakdown Flavor Products and Cembranoid Precursors). The major components of the First Volatile Fraction were 2-cyclohexene-1-one, 6-methyl-5-hepten-2-one, limonene and phenyl ethanol. The major components of Breakdown Flavor Products were isophorone, solanone, damascenone, 3-hydroxy-$\beta$-damascone, geranyl acetone, $\beta$-ionone, dihydroactinidiolide, norsolanadione, neophytadiene, hexahydrofarnesylacetone, farnesyl acetone and megastigmatrienone. The major cembranoid precursor compounds were dibutyl phthalate, duvatrenediols, 8,12-epoxy-14-labden-13-ol, 11-hydroperoxy-2,7,12(20)-cembratriene-4,6-diol, 12,15-epoxy-12,14-labadien-8-ol, 2,7,11-cembratrien-4,6-diol and 8,13-epoxy-14-labdien-12-ol. The NV scna results of tobacco types(flue-cured, burley and oriental) showed that each tobacco type has a characteristic flavor component profile.

• 대한화학회지
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• 제21권6호
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• pp.449-452
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• 1977

脂質 生産의 새로운 供給源으로 고려될 수 있는 石油炭化水素 醱酵에 의한 菌體脂質의 生成에 있어서 炭化水素의 炭素數의 影響과 그 脂肪酸의 組成을 檢討하였다. 菌株로서 Rhodotorula sp., 基質로서 炭素數가 짝수인 n-tetradecane과 n-hexadecane을 使用하여 容量 2l의 醱酵槽에서 溫度 $28^{\circ}C$, pH 4.0 ∼ 4.6, 酸素供給速度 0.4vvm, 攪拌速度 1000 rpm의 條件에서 醱酵시켜 生成된 菌體를 回收, 乾燥後 菌體脂質을 抽出하고 gas-liquid chromatography로 醱酵酸 組成을 檢索한 바, n-tetradecane과 n-hexadecane을 基質로 한 경우, 生成菌體의 脂質含量은 各各 12.0 및 25,8 %이었으며 菌體 脂肪酸은 大部分 炭素數가 짝수인 脂肪酸으로 構成되어 있었다.

• 대한화학회지
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• 제57권3호
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• pp.377-381
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• 2013

Thevetia peruviana (Yellow Oleander) seed oil was extracted with n-hexane in a soxhlet extractor. The ethanolysis and methanolysis of the oil were carried out with 50% of potassium hydroxide in ethanol and methanol respectively by weight of oil, as catalyst. The biodiesel was tested for biodegradability using E. coli. The percentage yield of the FAEE and FAME were 84.8% and 91.6% respectively. The biodegradability values of 81.4% and 86.2% were obtained for FAEE and FAME respectively after a period of 28 days. Other fuel quality parameters determined are the cetane index of 47.19 (FAEE) and 58.97 (FAME), flash point of $198^{\circ}C$ (FAEE) and $175^{\circ}C$ (FAME), kinematic viscosity at $40^{\circ}C$ of 5.21 $mm^2s^{-1}$ (FAEE) and 5.10 $mm^2s^{-1}$(FAME), pour point of $4^{\circ}C$ (FAEE) and $-2^{\circ}C$ (FAME) and a cloud point of $6^{\circ}C$ (FAEE) and $3^{\circ}C$ (FAME). Thus, Thevetia peruviana oil has a high potential for use in production of environmentally friendly biodiesel.

• 생약학회지
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• 제24권4호
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• pp.282-288
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• 1993

Very little utilization of the fruits of Malus baccata(Rosaceae) has been employed for food and medicinal plants except for preparing fruit beverages. But, it was estimated as valuable to investigate the chemical components for the botanical resource of this plant. In this study, it was found that the fruits of this plant contained primary long chain alcohol, ${\beta}-sitosterol$, campesterol, ursolic acid and ${\beta}-_D-glucosides$ of ${\beta}-sitosterol$ and campesterol. However, phloretin(dihydrochalcone) and its 5-O-glucoside(phloridzin) known as plant growth regulators in many Rosaceae plants were not found in this plant material by co-TLC analysis with authentic specimens. Although plant sex hormone, estrone, was often contained in relates of M. baccata, e.g., Prunus spp., Crataegus spp. and Malus spp., this compound was not detected in this fruit by comparison with an authentic material. By RIC chromatography, it was suggested that the Soxhlet extraction by the solvent of ether was excellently useful to extract ursolic acid efficiently.

• 한국환경과학회지
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• 제14권4호
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• pp.413-425
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• 2005

The 16 priority PAHs (Polycyclic Aromatic Hydrocarbons) designated by US Environmental Protection Agency were analyzed for some digested sludges from wastewater treatment plants in Korea. PAHs are an important group of organic contaminants present in sewage sludge due to their persistence and toxic potential. PAHs were extracted from freeze-dried sludges using a methylene chloride-methanol (2:1) mixture in a soxhlet extractor. The extracts were cleaned-up by silica gel/alumina combination column and subsequently fed into gas chromatograph/mass spectrometer (GC/MS) for determining PAH contents. The sum of the 16 PAHs in the sewage sludge varied from 534.8 to $5754.5 {\cal}ug/{\cal}kg$, dry wt.. In the sewage sludge, phenanthrene appears as the most abundant PAHs, followed by naphthalene, pyrene, fluoranthene. Source of the investigated sewage sludges relatively predominated pyrogenic. PAHs levels of sewage sludges in Korea appeared to be lower than those in other countries.

• 방사선산업학회지
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• 제4권1호
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• pp.19-23
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• 2010

Vinyl ester (VE) resins, introduced in the late 1960s, have made large strides in reinforced plastics applications as adhesive and matrix materials on their appropriate mechanical performance characteristics in the glassy state. Generally, VE resins are a group of dimethacrylate resins based on bisphenol A type epoxy resin. They exhibit easy handling properties as well as good resistance to most chemical agents due to their mechanical and thermal properties. In this study, the effects of curing methods of vinyl ester resins on gel contents, flexural strength and dynamic mechanical properties were investigated. Thermal curing (room temperature, $80^{\circ}C$) and electron beam curing were used to crosslink a VE resin/styrene complex (65/35 wt%) with methyl ethyl ketone peroxide (MEKPO) as a catalyst and an 8 wt% cobalt naphthenate in styrene solution as a accelerator. For the samples, gel contents as well as flexural strength and dynamic mechanical properties were characterized and compared by soxhlet apparatus, universal testing machine (UTM) and dynamic mechanical analysis (DMA). As a result, the electron-cured VE resin was confirmed as a better condition than those for gel contents, flexural strength and dynamic mechanical properties, respectively.

• Entomological Research
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• 제48권5호
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• pp.362-371
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• 2018

Chemical insecticides released into the environment may have adverse biological effects. Therefore, there is a need for ecofriendly insecticides for mosquito control. Xerophytic plant extracts that may provide more ecofriendly active component were evaluated against Culex pipiens 4th instars. Plant extracts prepared using different solvents with a Soxhlet apparatus and different concentrations were tested against Culex pipiens larvae. The effects were observed at 24 h and 72 h intervals and $LD_{50}$ and $LD_{90}$ values determined. Chloroform ($CHCl_3$) and ethyl acetate (EtOAc) extracts of Althaea ludwigii were the most effective against Cx. pipiens $4^{th}$ instars, but were highly dependent on extract concentrations and exposure time. Results suggest that A. ludwigii extracts contain bioactive compounds, such as phenols and saponins, that may provide effective Cx. pipienslarval control. However, the extract was found to be toxic to zebrafish larvae, and may be toxic to other aquatic fauna. Further studies to determine the active components and toxicity to other fauna are needed.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 춘계학술대회
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• pp.95-95
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• 2020

The groundnut (Arachis hypogaea L.), also known as peanut, is a high amount of good-quality vegetable oil in seeds cultivated worldwide. The aim of this study was to evaluate and analyze oil composition of 83 groundnut accessions collected from 7 countries include Korea and Philippines. Total oil contents were recovered by Soxhlet extraction and the fatty acid compositions were analyzed by using gas chromatography. Total oil contents of 83 groundnut accessions showed a significant variability among the entire domain of collections and rangerd from 44.59 to 57.58 %. The averages of palmitic and stearic acid were 11.36 and 3.39 % ranged from 8.77 to 13.65 %, and 1.88 to 7.22 %, respectively. Oleic and linoleic acid showed a wide variation which ranged from 40.32 to 61.67 %, and 22.54 to 41.99 %, respectively. Arachidic acid was ranged from 0.93 to 2.42 %. Significant negative correlation was observed between oleic and linoleic acid.

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.640-647
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• 2008

Breed differences in adult animals are determined during fetal development. If interventions are to be developed that influence growth of muscle and fat, it is important to know at which time during gestation breed differences appear and are fixed. The objective of this study was to characterize fetal development in cattle of different breeds. Pregnant cows of 4 cattle breeds with different growth impetus and muscularity were slaughtered under normal processing conditions and the fetuses were removed. German Angus, a typical beef cattle; Galloway, a smaller, environmentally resistant beef type; Holstein Friesian, a dairy type; and Belgian Blue, an extreme type for muscle growth were used. Fetuses of each breed were investigated at 3, 6, and 9 mo of gestation. Fetuses were weighed and dissected into carcass, organs, and muscles. Body fat weight was obtained using the Soxhlet extraction method. Fetal weight increased most rapidly in the third trimester of gestation mainly due to the accelerated muscle and fat deposition. The organ weight to body weight (BW) ratios decreased and the muscle and fat weight to BW ratios increased. At 3 mo of gestation, Galloway fetuses had the significantly smallest BW, half-carcass weight, leg weight, organ weight, muscle weight and shortest leg length. In contrast, Holstein fetuses had the significantly greatest BW, liver, kidney, and lung weights and significantly longest leg length among the 4 breeds, but no differences between Holstein Friesian and Belgian Blue were detected in half-carcass and leg weight. Indeed, Belgian Blue fetuses had the significantly greatest half-carcass weight, leg weight, and muscle weight at 9 mo of gestation, and Galloway had a significantly greater body fat to BW ratio than Holstein Friesian and Belgian Blue. These differences were not evident at 3 and 6 mo of gestation. These data show that the profound increase of tissue and organ weights occurred in later gestation in cattle fetuses even though breed differences were evident as early as 3 mo of gestation. Depending on the tissue of interest, impacting fetal growth likely needs to occur early in gestation before the appearance of breed-specific differences.

• 대한화학회지
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• 제39권7호
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• pp.513-523
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• 1995

다이옥신은 환경에 미량으로 존재하며 직접, 간접적인 경로를 통해 인체로 들어와 심각한 문제를 일으키는, 화학적으로 안정하고 잔류성과 독성이 강한 오염물질이다. 쓰레기 처리를 위한 소각로 시설은 다이옥신에 대한 대기오염의 주원인으로 알려져 있는데 연소시 소각로내에서와 배기가스 제어과정 중 다이옥신이 발생되는 것으로 보고되고 있다. 본 연구에서는 쓰레기 소각로에서 연소 후 생성된 바닥재 시료를 채취하여 다이옥신과 퓨란류를 조사하였다. 시료의 전처리는 EPA방법을 개선하여 불필요한 과정을 생략하면서 높은 회수율을 유지하였고 최종 정량은 고분해능 기체 크로마토그래피/고분해능 질량분석기(HRGC/HRMS)를 이용하여 분석하였다. 바닥재 시료를 분석한 전체 다이옥신의 양은 8.05 ng/g, 퓨란은 4.75 ng/g정도이었으며 2,3,7,8-TCDD는 6.93 pg/g이 검출되었고 염소원자 가 6~7개 치환된 다이옥신과 퓨란이 가장 많이 검출되는 경향을 볼 수 있었다.