• Environmental Analysis Health and Toxicology
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• v.20 no.3 s.50
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• pp.237-242
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• 2005

This study il focused on the hepatopreventive effect in cirrhotic rats induced by N, N -dimethylnitrosamine treatment when organir Lulfur -containing compoundE were orally injected. Biochemical parameters (aspatate transaminase (AST), alanine transaminase (ALT) alkaline phosphatase (ALP), 1-protein and t-bilirubin) were measured in serum injured liver tissue. The increased AST and ALT values were significantly reduced by organic sulfur-containing compounds at the oral dotes of 50 mg/kg. The result of morphological changes have illustrated the accumulation of liver damages, Each as inflammatory cell accumulation and cirrhosis, caused by N, N-dimethylnitrosamine. Also, it was found that liver damages were prevented by the treatment of organic sulfur- containing compounds.

• Journal of environmental and Sanitary engineering
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• v.13 no.1
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• pp.135-146
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• 1998

In this study, we investigated to measured concentration, seasonal characteristics and load quantity of volatile organic compounds(VOCs) for 11 sites in the main stream and 8 sites in the branch stream of Kumho river, during from October 1995 to April 1997. As a results, the small amount of volatile compounds, such as dichloromethane, chloroform, toluene, benzene, trichloroethene, tetrachloroethene, p-xylene and 1,3,5-trimethyl-benzene were detected from the main stream of Kumho river. Also detected to dichloromethene, chloroform, toluene, benzene, trichloroethene, tetrachloroethene, ethylbenzene, p-xylene, 1,3,5-trimethylbebzene and 1,2,4-trimethylbenzene in the branch stream, and dichloromerhane, chloroform and toluene were detected to all site of sampling. And seasonal variation of volatile organic compounds showed higher concentration in the July 1996 as a winter season than January 1997 as a summer season in most places. Also the load quantity of volatile organic compound at Gangchang site in the last downstream of Kumho river, was in order of chloroform > dichloromethane > toluene > trichloroethene.

• Bulletin of the Korean Chemical Society
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• v.23 no.6
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• pp.856-861
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• 2002

The general reducing charagteristics of a newly synthesized reducing agent, lithium(2.3-dimethyl-2-butyl)-${\iota}$-butoxyborohydride (Li $Thx'BuOB_2$, 1), in tetrahydrofuran (THF) toward selected organic compounds containing representative fundtional groups under practical has been examined. The reagent revealed an interesting and unique reducing characteristics. Especially, the stereoselectivity in the reduction of cyclic ketones was extraordinary. Thus, the introduction of bulky alkyl and alkoxy groups into the parent borohydride affonds a high stereoselectivity. In general, the reducing power of the reagent is somewhere between the dialiylborohydride and the parent borohydride. This permits the reagent to be a reagent of choice for selecitive reduction of organic compounds with an improved selectivity.

• Journal of odor and indoor environment
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• v.17 no.4
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• pp.396-403
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• 2018

In this study, volatile organic compounds (VOCs) emitted from printing industries were analyzed, and an inorganic adsorbent, ${\gamma}-alumina$, was selected for the effective control of the VOC emissions. Printing processes commonly require inks, thinners, and cleaners, and they were mixed organic solvents containing aromatic compounds, ketones, and alcohols. Therefore, toluene, methyl ethyl ketone (MEK), and isopropyl alcohol (IPA) were selected as model compounds for this study. The adsorptive properties using ${\gamma}-alumina$ were determined for the model compounds. Both batch isotherm and continuous flow column tests demonstrated that the adsorption capacity of MEK and IPA was 3~4 times higher than that of toluene. The column test performed at an inlet toluene concentration of 100 ppm showed that an 80% breakthrough for toluene was observed after 3 hours, but both MEK and IPA were continuously adsorbed during the same time period. A numerical model simulated that the ${\gamma}-alumina$ could remove toluene at a loading rate of 0.4 mg/min only for a 4-hour period, which might be too short of a duration for real applications. Consequently, lifetime enhancement for ${\gamma}-alumina$ must be implemented, and ozone oxidation and regeneration would be feasible options.

• Korean Journal of Environmental Agriculture
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• v.7 no.2
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• pp.136-145
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• 1988

To investigate the seasonal changes of various organic and inorganic compounds in compost, carbon compounds in compost were analyzed at various composting periods. Contents of organic matter, cellulose, total carbon, organic carbon and biodegradable carbon in compost were decreased with the progress of composting. In contrast, contents of lignin and nonbiodegradable carbon were increased a little with the progress of composting, but effective contents of lignin were decreased with the lapse of composting time, while effective contents of nonbiodegradable carbon were not changed. Total carbon contents in organic matter in compost were decreased within 9 weeks after composting, and then increased thereafter. Difference between average values of total and biodegradable carbon contents was 6.2%. Actual decay rates of all the carbon compounds were higher than decay rates of the compounds at all the experimental periods. Both of actual decay rate and decay rate of all the carbon compounds were increased rapidly within 2 weeks after composting, and thereafter the rates were increased slightly with the lapse of composting time. Especially the decay rates of cellulose were increased from 9 to 21 weeks after composting. Actual degradation capacity showed the same tendency to degradation capacity of all the carbon compounds in compost. Decay rate and degradation capacity of lignin in compost had minus values, while actual decay rate and actual degradation capacity had plus values. Highly positive correlations were observed among organic matter, cellulose, total carbon and biodegradable carbon one another. Nonbiodegradable carbon showed highly negative correlation with organic matter, cellulose, total carbon, organic carbon and biodegradable carbon, respectively. The same tendencies were observed between lignin and organic matter, cellulose, total carbon, organic carbon and biodegradable carbon. Highly positive correlation was observed between lignin and nonbiodegradable carbon in compost.

• Journal of the Korean Chemical Society
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• v.52 no.6
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• pp.712-716
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• 2008

• Journal of Environmental Science International
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• v.8 no.6
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• pp.699-704
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• 1999

The Photodegradation efficient of total organic compounds in the drinking water has been studied using the methods of photocatalytic reaction and laser beam irradation. The results are summarized as follows; 1. The photodegradation efficiency of total organic compounds shows as $50\%\;to\;80\%$ as within one hour and after this the efficiency is decreased slowly. 2. The photodegradation efficiency of total organic compounds shows as 65 to $90\%$ within 3.3min. when Nd : YAG beam is irradiated to the water layer. 3. An excellent observation of the organic compound removal efficiency gives revealed in that case of the longest wavelength of 532nm is irradiated among the three kinds of laser beam sources of 532nm, 355nm and 266nm. 4. The organic compound removal efficiency shows high in the case of UV beam irradiation in the thin layer of water. However the efficiency is not depended on the thickness of water layer severely. 5. The removal efficiency of the organic compounds in the direct irradiation shows higher than the indirect irradiation in the case of UV beam, but the efficiency is not depended on the direction of irradiation in the case of Nd : YAG beam irradiation.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1255-1259
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• 2004

The objective of this study was to evaluate the effects of halogenated compounds, organic acids, unsaturated fatty acids and their mixtures on in vitro methane production and fermentative characteristics of mixed rumen microorganisms. Agents used in two in vitro experiments were bromoethanesulfonic acid (BES) and pyromellitic diimide (PMDI) as halogenated compound, fumarate and malate as organic acid, and linoleic acid and linolenic acid as unsaturated fatty acid sources. Ruminal fluid collected from a Holstein steer fed tall fescue and concentrate mixtures was incubated at $39^{\circ}C$ for 48 h with addition of those materials. Single supplementation of halogenated compounds, organic acids or unsaturated fatty acids decreased in vitro methane production (p<0.05). The second experiment was designed to investigate effects of combination of one of halogenated compounds and either organic acids or fatty acids on methane production. Lower concentration of methane and lower A:P ratio were observed with PMDI compared with BES (p<0.01). In general medium pH, VFA, total gas and hydrogen production, and dry matter degradability were affected by addition of the same compounds. In addition, PMDI+malate treatment resulted in the highest molar proportion of propionate, and lowest A:P ratio and methane production (p<0.01). Hydrogen production was highest in PMDI+linolenic acid and lowest in BES+malate treatment (p<0.01). PMDI+malate combination was the most recommendable in reducing methane production without too much influence on digestibility under conditions of present studies.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.4
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• pp.413-427
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• 2006

It is necessary to study and develop guidelines for providing comfort and health indoor air quality for office workers since air-tight envelope system of current office building may cause poor indoor air quality. The purpose of this study is to propose guideline for volatile organic compounds in office base on the field study, human health risk assessment and cost-benefit analysis. The field study was conducted to survey the concentrations of volatile organic compounds in indoor air of 69 offices from June to September, 2005 in Seoul and Gyeonggi-do. The rate of excess to guideline of volatile organic compounds in indoor air of new apartment on the Ministry of Environment in Korea(MOE) was surveyed 37.6% for benzene, 6.8% for toluene, and 1.5% for ethylbenzene. As the result of human health risk assessment, mean cancer risk did not exceed 10-6 which is guideline of US.EPA. Also, total hazard index did not exceed 1 which is guideline of US.EPA. Through the cost-benefit analysis of angle on the social-economics to verify the necessary to establish the standards of volatile organic compounds for improvement and development of indoor air quality in office, the present value of benefit was higher than the present value of cost. With the above considerations in mind, it is suggested that the field study for indoor air quality in offices should be expanded and human health risk assessment and cost-benefit analysis be performed th offer scientific data for decision-making of policy for improvement and management of indoor air quality in office.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.319-322
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• 2005

Porous building materials are not only sources of indoor air pollutants such as volatile organic compounds (VOCs) but they are also strong sinks of these pollutants. Volatile organic compounds have been implicated in impaired spermatogenesis, increase in the incidence of malformed sperm and decrease in the percentage of moving sperm. The aim of this study was to determine and compare the direct effects of various volatile organic compounds (phenol, formaldehyde; HCHO, ethanol, toluene, styrene) on motility and survival rate of human sperm in vitro. Semen samples from 3 health subjects were prepared using swim-up method and 1-10mM volatile organic compounds were added to the test medium. HCHO and phenol produced significant decreases in the motility and survival rate with a different potency. The most potent inhibition of motility and survival rate was observed after exposure to HCHO. Less than 1mM HCHO significantly inhibited sperm motility. When ethanol is added directly to sperm, at concentrations equivalent to that in serum after heavy drinking, these damaging effects were lowest compared with other volatile organic compounds. Present study shows that each compound has differential toxic potency to human sperm and we need special caution for the use of HCHO and phenol.