• 한국연초학회지
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• 제28권2호
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• pp.75-82
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• 2006

This study was carried out to investigate the changes of free sugars, non-volatile organic and fatty acids in flue-cured leaf tobacco during aging. The threshed leaf tobacco(B1O and C1L) produced in 2002 crop year was aged for 21 month in warehouse of Oc-Cheon Leaf Tobacco Processing Factory. The leaf tobacco were sampled at three month intervals for analysis of free sugars, non-volatile organic and fatty acids. The major free sugars of flue-cured were glucose and fructose regardless of tobacco grades. After aging period of 21 months, the contents of glucose and fructose showed a tendency to slightly decrease, and there was no appreciable change in the contents of sucrose in B1O and C1L grades. The major compound of non-volatile organic acid and fatty acid were malic, oxalic and citric, linolenic, linoleic and palmitic acid regardless of tobacco grade. After aging period of 21 months, the contents of malic, malonic, oxalic and fumaric acid showed a tendency to slightly decrease, whereas succinic acid was slightly increased, and maleic acid was not changed in B1O and C1L grades. The decreases in fatty acid contents in B1O and C1L grade tobacco loaves after 21 month aging were 16.5% and 9.8%, respectively. The decreases in linolenic acid contents in two grades were the highest, showing 22.1% and 12.0% reduction after 21 month aging.

• 한국식품과학회지
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• 제31권6호
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• pp.1440-1446
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• 1999

국내외에서 구입한 42개의 식초 시료에 대해 비휘발성 유기산, 당, 아미노산, 휘발성 성분들을 종합적으로 분석하여 화학 성분에 의한 양조, 사과, 현미식초의 차별화 가능성을 검토하였다. 비휘발성 유기산으로는 malic, succinic 및 lactic acid, 당 성분으로는 fructose와 glucose, 아미노산으로는 lysine, serine, leucine, valine 및 alanine, 휘발성 성분으로는 1-hexanol, acetaldehyde, 3-methyl-1-butanol, 2-methylpropanoic acid, isopropyl butanoate 및 ethanol이 식초의 종류별 차별화에 유용한 성분으로 밝혀졌다. 이러한 열 여섯 종의 성분들 중에서도 malic acid, lysine, succinic acid, glucose, lactic acid 및 1-hexanol을 식초의 차별화에 가장 크게 기여하는 화학 성분으로 정의할 수 있었다. 양조식초는 특징적인 성분이 없었으며, 사과식초는 malic acid와 1-hexanol이, 현미식초는 lysine과 lactic acid의 함량이 다른 종류의 식초에 비해 많은 것이 특징이었다.

• Mycobiology
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• 제44권3호
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• pp.162-170
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• 2016

In this paper, we demonstrate the ability of Arabidopsis thaliana to detect different mixtures of volatile organic compounds (VOCs) emitted by the common indoor fungus, Aspergillus versicolor, and demonstrate the potential usage of the plant as a bioindicator to monitor fungal VOCs in indoor air. We evaluated the volatile production of Aspergillus versicolor strains SRRC 108 (NRRL 3449) and SRRC 2559 (ATCC 32662) grown on nutrient rich fungal medium, and grown under conditions to mimic the substrate encountered in the built environment where fungi would typically grow indoors (moist wallboard and ceiling tiles). Using headspace solid phase microextraction/gas chromatography-mass spectrometry, we analyzed VOC profiles of the two strains. The most abundant compound produced by both strains on all three media was 1-octen-3-ol. Strain SRRC 2559 made several terpenes not detected from strain SRRC 108. Using a split-plate bioassay, we grew Arabidopsis thaliana in a shared atmosphere with VOCs from the two strains of Aspergillus versicolor grown on yeast extract sucrose medium. The VOCs emitted by SRRC 2559 had an adverse impact on seed germination and plant growth. Chemical standards of individual VOCs from the Aspergillus versicolor mixture (2-methyl-1-butanol, 3-methyl-1-butanol, 1-octen-3-ol, limonene, and ${\beta}-farnesene$), and ${\beta}-caryophyllene$ were tested one by one in seed germination and vegetative plant growth assays. The most inhibitory compound to both seed germination and plant growth was 1-octen-3-ol. Our data suggest that Arabidopsis is a useful model for monitoring indoor air quality as it is sensitive to naturally emitted fungal volatile mixtures as well as to chemical standards of individual compounds, and it exhibits relatively quick concentration- and duration-dependent responses.

• 한국축산시설환경학회지
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• 제19권2호
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• pp.89-94
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• 2013

This study was performed to investigate the effect of beet plup and IRG (Italian ryegrass) dry powder in fattening pig diet on reducing concentration of odorous compounds in the pig slurry. Fifty fattening boars [(Landrace ${\times}$ Yorkshire) ${\times}$ Duroc] were randomly assigned to one of 3 treatments (control, beet plup 5%, and IRG 5%). Pigs (BW 50~110 kg) were fed diets formulated to meet the Korean Feeding Standard (2012) and their excretion was collected from the slurry pits. Short chain fatty acid (SCFA) and branched chain fatty acid (BCFA) were higher in beet plup (31,786, 3,985 ppm) and IRG (32,755, 4,261 ppm) treatments, which was not different among treatments (p>0.05), compared to control (p<0.05). Concentrations of phenols and indoles were highest in beet plup (183.83, 168.59 ppm) and IRG (9.32, 8.92 ppm) treatments. Altogether, addition level of two contents was not appropriate to decrease concentration of odorous compounds.

• 한국축산시설환경학회지
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• 제19권2호
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• pp.101-108
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• 2013

This study was to investigate the effect of addition levels of odor reducing contents on reducing the concentration of odorous compounds. Slurry treatments included three levels mixture of horseradish powder (HP), mushroom waste (MW) and probiotics powder (PP), and non-treatment control (n=4 each group). Levels of odorous compounds were measured from the liquid slurry incubated in room temperature ($20{\sim}25^{\circ}C$) for 2 wk in chamber whose structure is similar to slurry pit. Concentration of phenols and indoles was lower (p<0.05) in level 1, which was mixed HP 0.01%, MW 0.4% and PP 0.004% (98.69, 1.87 ppm) compared to control. Short chain fatty acid (SCFA) and branched chain fatty acid (BCFA) was lowest (p<0.05) level 1 (6,557, 1675 ppm). Taken together, lower level are effective in reducing odorous compounds in pig slurry.

• Safety and Health at Work
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• 제10권2호
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• pp.229-236
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• 2019

Background: Emerging reports suggest the potential for adverse health effects from exposure to emissions from some additive manufacturing (AM) processes. There is a paucity of real-world data on emissions from AM machines in industrial workplaces and personal exposures among AM operators. Methods: Airborne particle and organic chemical emissions and personal exposures were characterized using real-time and time-integrated sampling techniques in four manufacturing facilities using industrial-scale material extrusion and material jetting AM processes. Results: Using a condensation nuclei counter, number-based particle emission rates (ERs) (number/min) from material extrusion AM machines ranged from $4.1{\times}10^{10}$ (Ultem filament) to $2.2{\times}10^{11}$ [acrylonitrile butadiene styrene and polycarbonate filaments). For these same machines, total volatile organic compound ERs (${\mu}g/min$) ranged from $1.9{\times}10^4$ (acrylonitrile butadiene styrene and polycarbonate) to $9.4{\times}10^4$ (Ultem). For the material jetting machines, the number-based particle ER was higher when the lid was open ($2.3{\times}10^{10}number/min$) than when the lid was closed ($1.5-5.5{\times}10^9number/min$); total volatile organic compound ERs were similar regardless of the lid position. Low levels of acetone, benzene, toluene, and m,p-xylene were common to both AM processes. Carbonyl compounds were detected; however, none were specifically attributed to the AM processes. Personal exposures to metals (aluminum and iron) and eight volatile organic compounds were all below National Institute for Occupational Safety and Health (NIOSH)-recommended exposure levels. Conclusion: Industrial-scale AM machines using thermoplastics and resins released particles and organic vapors into workplace air. More research is needed to understand factors influencing real-world industrial-scale AM process emissions and exposures.

• Asian Journal of Atmospheric Environment
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• 제12권2호
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• pp.127-138
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• 2018

This study measured indoor and outdoor levels of hydrocarbon volatile organic compounds (VOCs), such as benzene, toluene, ethylbenzene, and xylene isomers (collectively referred to as BTEX), as well as 13 carbonyl compounds, at 20 homes in Seoul, South Korea. Along with the sampling of BTEX and carbonyls, indoor concentrations of the air pollutants nitrogen oxide (NO) and carbon dioxide ($CO_2$) were also measured at each home. These measurements were used to understand the characteristics of BTEX and carbonyls by calculating the various ratios and correlation coefficients between measured contaminant levels. We found that carbonyls were mostly originated from indoor sources, while BTEX were originated from both indoor and outdoor sources. A high correlation between indoor levels of NO and BTEX indicated that traffic emissions were also an important sources of BTEX.

• 한국연초학회지
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• 제28권2호
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• pp.144-151
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• 2006

A measurement uncertainty for analysis of volatile organic compound (benzene) in cigarette mainstream smoke was carried out. In this study one point re-calibration method was used to estimate uncertainty for benzene. The measurement uncertainty was calculated based on the uncertainty sources of each analysis step, quality appraisal sources, drift and repeatability. As a result, the concentration and expanded uncertainty of benzene in cigarette mainstream smoke were measured as $38.08{\pm}4.36{\mu}g/cig$. Relative uncertainty of drift and repeatability obtained were 5% and 3%, respectively.

• 한국세라믹학회지
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• 제53권2호
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• pp.134-138
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• 2016

Porous $Co_3O_4$ spheres with bimodal pore distribution (size: 2-3 nm and ~ 30 nm) were prepared by ultrasonic spray pyrolysis of aqueous droplets containing Co-acetate and polyethylene glycol (PEG), while dense $Co_3O_4$ secondary particles with monomodal pore distribution (size: 2-3 nm) were prepared from the spray solution without PEG. The formation of mesopores (~ 30 nm) was attributed to the decomposition of PEG. The responses of a porous $Co_3O_4$ sensor to various indoor air pollutants such as 5 ppm $C_2H_5OH$, xylene, toluene, benzene, and HCHO at $200^{\circ}C$ were found to be significantly higher than those of a commercial sensor using $Co_3O_4$ and dense $Co_3O_4$ secondary particles. Enhanced gas response of porous $Co_3O_4$ sensor was attributed to high surface area and the effective diffusion of analyte gas through mesopores (~ 30 nm). Highly sensitive porous $Co_3O_4$ sensor can be used to monitor various indoor air pollutants.

• 설비공학논문집
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• 제16권1호
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• pp.1-7
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• 2004

This study has been numerically conducted to investigate the removal efficiency of Volatile Organic Compound (VOC) for different photocatalytic honeycomb filters. Recently, the photocatalysis is being applied to air-cleaner, air-conditioner and vacuum-cleaner with the capability of air-purification, sterilization and antibiosis. However, photocatalysis is less efficient than other methods for removing VOC except in the case of low concentration. So far most of studies have focused on an improvement of the photocatalytic materials, but this study have placed emphasis on the improvements of shape of photocatalytic honeycomb filter. UV irradiation, concentration profile and pressure drop have been investigated for different cross sections of filters and for different filter lengths. Light intensity is dropped sharply with increasing distance from the UV-lamp, and becomes very low in the middle of the filters. Since photocatalytic reaction rate is a function of light intensity, VOC concentration gradient might be small in the middle of long filters. Thus, most of reaction have risen within only three times of dimensionless axial distance. These results can be used effectively for the design of advanced photocatalytic honeycomb filters.