• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.153-154
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• 2018

As the air pollution progresses, the pollution degree of the indoor air quality is increased, and when the pollution degree of the indoor air quality is increased, it causes respiratory diseases and skin diseases. In addition, volatile organic compounds are released from the materials used for architectural interior decoration, and volatile organic compounds are the main cause of polluting indoor air quality. In order to improve indoor air quality, we tried to secure indoor air quality pollution by using photocatalyst which has the function of decomposing harmful substances. photocatalyst is a material that promotes chemical reaction by absorbing light. The photocatalyst used in the experiment was TiO₂, In this study, an adsorption type hardener for reducing volatile organic compounds was prepared by photocatalytic reaction. the formaldehyde and CO₂ concentrations of the cured products were analyzed according to the TiO₂ content.

• Analytical Science and Technology
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• 제34권5호
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• pp.202-211
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• 2021

Volatile organic compounds (VOCs) in hazardous air pollutants (HAPs) have been regulated by the Air Pollution Control Act (1978) and their atmospheric concentrations have been monitored in 39 monitor sites in Korea. However, measurement standards of volatile organic compounds (VOCs) in HAPs at ambient levels have not been established in Korea. Primary reference gas mixtures (measurement standards) at ambient levels are required for accurately monitoring atmospheric VOCs in HAPs and managing their emissions. In this study, primary reference gas mixtures (PRMs) at 5 nmol/mol were developed in order to establish primary national standards of VOCs in HAPs at ambient levels. Primary reference gas mixtures (PRMs) were prepared in pressurized aluminum cylinders with special internal surface treatment using gravimetric method. Analytical methods using gas chromatography-flame ionization detector (GC-FID) coupled with a cryogenic preconcentrator were also developed to verify the consistency of gravimetrically prepared HAP VOCs PRMs. Three different columns installed in the GC-FID were evaluated and compared for the retention times and separation of eighteen target components in a chromatogram. Results show that the HAP VOCs PRMs at 5 nmol/mol were consistent within a relative expanded uncertainty (k=2) of less than 3 % except acrylonitrile (less than 6 %) and the 18 VOCs were stable for 1 year within their associated uncertainties.

• Mycobiology
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• 제49권1호
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• pp.69-77
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• 2021

The application of antagonistic fungi for plant protection has attracted considerable interest because they may potentially replace the use of chemical pesticides. Antipathogenic activities confirmed in volatile organic compounds (VOCs) from microorganisms have potential to serve as biocontrol agents against pre- and post-harvest diseases. In the present study, we investigated Galactomyces fungi isolated from rotten leaves and the rhizosphere of cherry tomato (Lycopersicon esculentum var. cerasiforme). VOCs produced by Galactomyces fungi negatively affected the growth of phytopathogenic fungi and the survival of nematodes. Mycelial growths of all nine examined phytopathogenic fungi were inhibited on agar plate, although the inhibition was more intense in Athelia rolfsii JYC2163 and Cladosporium cladosporioides JYC2144 and relatively moderate in Fusarium sp. JYC2145. VOCs also efficiently suppressed the spore germination and mycelial growth of A. rolfsii JYC2163 on tomatoes. The soil nematode Caenorhabditis elegans exhibited higher mortality in 24 h in the presence of VOCs. These results suggest the broad-spectrum activity of Galactomyces fungi against various plant pathogens and the potential to use VOCs from Galactomyces as biocontrol agents.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.3963-3970
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• 2012

Headspace (HS) and headspace solid-phase microextraction (HS-SPME) were studied for extracting volatile organic compounds (VOCs) from whole blood, with chemical and instrumental variables being optimized for maximum sensitivity: incubation at $60^{\circ}C$, equilibration for 30 min, pH 11, and 2 mL injection volume. Both techniques provided accurate analyses, with detection limits of 0.05-0.1 ng $mL^{-1}$ and 0.05-0.5 ng $mL^{-1}$. HS showed better sensitivity, reproducibility, and analysis times than HS-SPME. Overall levels of chloroform in whole blood were found to be 0.05-5.84 ng $mL^{-1}$; detected levels of benzene were 0.05-2.20 ng $mL^{-1}$.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제34권1호
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• pp.40-47
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• 1989

To elucidate the relationship of the Quality of aromatic tobacco to their chemical constituents, certain chemical components and leaf Quality by price were compared among leaves produced, 1) under 4 different light intensities during maturing stage in field, 2) under 4 different temperature of 20$^{\circ}C$. 25$^{\circ}C$. 30$^{\circ}C$ and control of l8-22-28$^{\circ}C$ in phytotron. As the light intensity decreased chlorophyll content of harvested leaves increased, but specific leaf weight and Quality of cured leaves lowered. The content of sugar. pet. ether exts. and volatile organic acids decreased, but total nitrogen, nicotine, ash and pH increased as the .light intensity decreased. As the growth temperature increased days to flower was shortened and the growth was decreased without significant difference in leaf Quality. With higher growth temperature the content of nitrogen, ash and pH increased, but sugar decreased with no difference in pet. ether exts., volatile organic acids and volatile neutral content. Several Quality indices were disscussed for the Quality evaluation of aromatic leaves for two groups, respectively.

• Journal of the Korean Society of Tobacco Science
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• 제18권1호
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• pp.76-84
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• 1996

Flue-cured tobaccos(cv. NC82, grade AB3O-1) expanded by super steam, volatile organic solvents(tricuorofluoromethane, propane), carbon dioxide, nitrogen, and by freeze-drying were examined for their physico-chemical properties. The expanding rate by using the organic solvents or carbon dioxide at the impregnated pressure was 70% or more, whereas the rate by super steam and freeze-drying was 49.4 and 42.9%, respectively. The contents of total sugar, alkaloid and ether extracts of the expanded tobacco by organic solvents or carbondioxide were decreased to 27.6, 20% or more, and 13%, respectively, when compared to non-expanded one. The contents of citric acid of the tobacco expanded by using trichlorofluoromethane and carbon dioxide were increased to 19.1, 14.0%, respectively. Linoleic acid in the tobacco expanded by super steam or trichlorofluoromethane was also increased to 17.3%, but malonic acid in the tobacco expanded by super steam was 18.5% less than that in the non-expanded one. Nineteen essential oil among 22 assayed in this experiment were decreased in the expanded tobaccos. Key words : expanding method, tobacco, physico-chemical properties.

• Applied Chemistry for Engineering
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• 제21권6호
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• pp.680-683
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• 2010

Nano carbon balls (NCBs), activated carbons (ACs) and their mixture (new carbon mixtures, NCMs) were used to reduce volatile organic compounds (VOCs) emitted from the automobile felt. The optimum analytical method to measure the trace amount of the VOCs, including formaldehyde and acetaldehyde, has been established by utilizing high performance liquid chromatography (HPLC) and gas chromatography (GC). The levels of formaldehyde and acetaldehyde released from newly produced felt were in the ranges of 0.3~6.0 ppm and 0.2~3.0 ppm, respectively. After 14 days of aging at the room temperature, however, their levels were still in the ranges of 0.2~0.5 ppm and 0.2~0.4 ppm, respectively. By applying NCMs of 2 wt% to the automobile felt, the amount of the total volatile organic compounds (TVOCs) was reduced under the chronic inhalation minimum risk level of $0.32mmmm{\mu}g/TP$.

• Journal of the Korean Chemical Society
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• 제39권8호
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• pp.635-642
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• 1995

Improved sample introduction system has been investigated for the determination of volatile organic compounds in water using a purge & trap preconcentration apparatus and a capillary gas chromatography/mass spectrometry. The present limitations associated with the moisture control module and cryorefocusing system suggested by EPA were discussed. To solve the problems such as improper separation of peaks due to the adsorption of water and contamination of purge & trap system, a more efficient connection system between the purge & trap apparatus and the gas chromatograph was introduced and the optimum operational conditions were suggested. A carbopack B/carboxen 1000 and 1001 trap was used for the purge & trap procedure and a custom made crosslinked dimethyldiphenylpolysiloxane capillary column was used for the separation of compounds. Accuracy and precision of the method suggested in this report were examined and the method detection limit of each compound was proposed for the simultaneous determination of 54 volatile organic compounds in water.

• Journal of the Korean Chemical Society
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• 제44권4호
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• pp.343-349
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• 2000

Volatile Organic Compounds(VOCs) emitted form electronicSince toluene, xylene, cyclohexanone, and benzofuran will bring on the deleterious smell and the health risk, eventhough very small amount of these areexposed to human body, quantitative analysis was achieved by GC-MS system. As a result of these analyses, except PCB(CEM-1) of which is one of the electronic parts, the left of electronic parts represented, imme-diately form 30 minutes to 1 hour after heating, the trends that toluene, xylene, cyclohexanone and phenol were consecuticely emitted very high. and toluene, xylene, phenol, cyclohexanone, and benzofuran from most of the electronic parts were emitted very frequently within the measuring period. Finally, Trans of electronic parts showed the highest concentration of emission, and xylene(550~2482 ${\mu}g/m^2$) was the most noticeably emitting compound of VOCs.

• Applied Chemistry for Engineering
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• 제24권2호
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• pp.171-176
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• 2013

The need of volatile organic compound (VOC) free coating material has been increased to solve environmental problems such as the global warming. Nowadays, about 70~80% of coating materials used in the worldwide are a liquid type. Therefore, the development of non-solvent coating material that can minimize VOCs emissions is necessary to solve the global warming problem. In this study, acrylic monomers were added to develop non-solvent paints in order to improve disadvantages of the poor adhesion of a conventional phenolic resin caused by acidification. As a result, the blend resins of 2.818 Mpa phenol- formaldehyde resin/poly methyl methacrylate (PE/PMMA) has the best properties and performances for the adhesives.