• Title/Summary/Keyword: chemicals

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Current and Future Prospects for Insect Behavior-modifying Chemicals in China

  • Du, Jia-Wei
    • Journal of Applied Biological Chemistry
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    • v.43 no.4
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    • pp.222-229
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    • 2000
  • In this paper we will assess the feasibility of some insect behavior-modifying chemicals for insect control, such as male orientation inhibitor, female calling interrupter and female attractant of cotton bollworm Helicoverpa armigera. These behavior-modifying chemicals have advantages of simple chemical structure, easy to synthesize and low price of products. The effects of sub-lethal insecticides on insect chemical communication system and the differences of pheromone communication systems between the resistant and susceptible strain of H. armigera will also be discussed.

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The study about optimum of chemicals injection rate in the water treatment plant (정수장 약품 주입율의 최적화)

  • Han, Tae-Hwan;Ryu, Jeong-Woong
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.766-768
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    • 1995
  • This paper presents the applied example of "A" city about optimum of chemicals imjection rate. The water treatment plant of "A" city make raw water into drinking water according to the injection of PAC, Alkali and chlorine. Computer performs multiple regression analysis about preoperation data, DCS has been done chemicals optimun control.

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Methodological Approach to Surveilance of Chemical Hazards in Worksite Environments (작업환경오염 화학물질의 유해성조사 방향연구)

  • 김오식
    • Journal of the Korean Society of Safety
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    • v.6 no.1
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    • pp.39-53
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    • 1991
  • Prior to being prepared the surveilance method and the surveilance system of chemical hazards, the employer's investigastion of the newly-registered-chemical hazards has been to be under obligation along with legislation of the Hazardous Chemicals Control Act and revision of the Industrial Safety & Health Act in 1990. In order to make up the chemical hazards examining plan and to frame the chemical hazards investigating system about the newly-registered chemicals and the existing hazardous chemicals in worksite environments, the KISCO's chemical hazards surveilance program is methodologically researched and presented.

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Chemicals for the Control of Streptomycin-resistant Tobacco Hollow Stalk Pathogen, Erwinia carotouora subsp. carotovora (Streptomycin 내성 담배줄기속썩음병균 방제약제 선발)

  • 강여규
    • Journal of the Korean Society of Tobacco Science
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    • v.18 no.1
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    • pp.60-65
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    • 1996
  • Chemicals including antibiotics and bactericides were screened for suppression of streptomycin-resistant Erwinia cmutouom subsp. cmutovom (Ecc) strains in laboratory and field conditions. Oxytetracycline, ethoquinolac and dichlorophen suppressed the growth of streptomycin-resistant Ecc strains in vitro. Fractional inhibitory concentration (FIC) indices of oxytetracycline and ethoquinolac mixed with streptomycin against the Ecc strains were equal to and less than one, respectively. Consequently the efficacy of those chemicals in mixture with sorptomycin were non-antagonistic But that of dichlorophen mixed with streptomycin was more than one, therefore the efficacy of the mixture was antagonistic. Spray of oxyteoucycline, ethoquinolac and agrimycin-100 on the topped burley tobacco plants was efficacious in reducing tobacco hollow stalk at the same level of sorptomycin treatment in three-year field trials, which suggests that those are promising chemicals to be alternative to streptomycin for control of tobacco hollow stalk.

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Styrene Epoxidation over Cobalt Cyclam Immobilized SBA-15 Catalyst

  • Sujandi;Prasetyanto, Eko Adi;Han, Sang-Cheol;Park, Sang-Eon
    • Bulletin of the Korean Chemical Society
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    • v.27 no.9
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    • pp.1381-1385
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    • 2006
  • Cobalt (cyclam) complex has been successfully immobilized onto SBA-15, and proven to be an active catalyst for the epoxidation of styrene with tert-butyl hydroperoxide as a terminal oxidant. The selectivity for styrene oxide was observed to be up to 66% with 40% styrene conversion after 12h reaction time. The reversible redox cycle between Co(III) and Co(II) couple which was supposed to play key role during the epoxidation reaction was supported by a cyclic voltametry analysis. The textural properties of the catalyst was characterized by XRD, N2 adsorption-desorption, and TEM analysis.

Occupational Cancers with Chemical Exposure and their Prevention in Korea: A Literature Review

  • Rim, Kyung-Taek
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.6
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    • pp.3379-3391
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    • 2013
  • The usage and types of chemicals being developed, with diversified new exposure of workers, are of natural concern to occupational disease. In Korea, with industrialization, application of many chemicals has increased. A large proportion of mortality and disease is due to cancer, and the causal hazardous agents include chemical agents, like heavy metals and so on. Due to the long latency period with malignancies and the fact they are usually found after workers' retirement, it is suggested that management policies must be established to prevent occupational cancers occurring among workers in Korea. To give a general description about the efforts to prevent the occupational cancer with exposure to chemicals, articles on the trends of occupational cancers were reviewed and summarized with related research and efforts for prevention in Korea. It is important to improve the understanding of occupational cancer and help to maintain sustainable and appropriate measures to guarantee workers safety and health.

Estimation of Initial Concentrations of Phenanthrene and Atrazine from Soil Properties and Bioavailability During Aging

  • Chung, Namhyun
    • Journal of Applied Biological Chemistry
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    • v.44 no.4
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    • pp.194-198
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    • 2001
  • Contaminated sites are often abandoned for an extended period of time, thus organopollutants becoming sequestered. The information on the initial concentrations of the contaminants would be helpful for the economic bioremediation of the chemicals. The present study estimated the initial concentrations of atrazine and phenanthrene through multiple regression analyses using soil properties and the amount of chemicals available in situ. Percentage mineralized or extracted was best correlated with organic C or logarithm of organic C, and the $R^2$ values were 0.548 and 0.894 for atrazine and phenanthrene, respectively. Estimation of the initial concentration of the chemicals was then calculated from both the percentage mineralized or extracted and the amount of chemicals extracted or mineralized. Results showed that the estimation of the initial concentration of the chemical at the time of contamination is feasible.

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A Study on Stability of AKD-Emulsion (AKD 에멀션의 안정성 평가)

  • Kwon, Won-Tae;Kim, Jeong-Hi;Shin, Jong-Ho;Park, Min-Tae
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2002.11a
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    • pp.209-217
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    • 2002
  • Stability deterioration of AKD emulsion was studied with respect of the physical change of emulsion particles and the chemical change of AKD itself. Four kinds of commercial emulsions were kept at RT, 40, 50, and $60^{\circ}C$ water bath, respectively. Viscosity, particle size distribution, and solid contents of the emulsions were measured with storage time. At the same time, by performing NMR and IR spectroscopy analysis of the solvent-extracted AKD from the emulsions, the qualitative and quantitative information about the deformation of the AKD itself were obtained. AKD was gradually hydrolyzed to become dialkylketone and higher storage temperature accelerated destabilization of the AKD emulsions.

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