• Bulletin of the Korean Chemical Society
• /
• v.28 no.12
• /
• pp.2139-2152
• /
• 2007

Ruthenium complex-catalyzed reactions often require highly qualified tuning of reaction conditions with substrates to attain high yield and selectivity of the products. In this review, our strategies for achieving characteristic ruthenium complex-catalyzed co-oligomerization of different alkenes are disclosed: 1) The codimerization of 2-norbornenes with acrylic compounds by new ruthenium catalyst systems of RuCl3(tpy)/Zn [tpy = 2,2':6',2''-terpyridine] or [RuCl2(η6-C6H6)]2/Zn in alcohols, 2) A novel synthesis of 2-alkylidenetetrahydrofurans from dihydrofurans and acrylates by zerovalent ruthenium catalysts, such as Ru(η4-cod)(η6-cot) [cod = 1,5-cyclooctadiene, cot = 1,3,5-cyclooctatriene] and Ru(η6-cot)(η2-dmfm)2 [dmfm = dimethyl fumarate], 3) Regio- and stereoselective synthesis of enamides by Ru(η6-cot)(η2-dmfm)2-catalyzed codimerization of N-vinylamides with alkenes, and 4) Unusual head-to-head dimerization of styrenes and linear codimerization of styrenes with ethylene by Ru(η6-cot)(η2-dmfm)2 catalyst in the presence of primary alcohols.

• Journal of Environmental Science International
• /
• v.13 no.6
• /
• pp.519-525
• /
• 2004

Air pollution from the Daegu industrial complex (Die) in Korea has been a common nuisance and cause of complaints for nearby residents. The current study measured the indoor and outdoor levels of six VOC (benzene, toluene, ethylbenzene, and three isomeric xylenes) at two residential areas with a different proximity to the ODIC, plus the ambient levels at two industrial areas within the boundary of the DDIC. The QA/QC program included the range of correlation coefficient (0.94-0.99) for calibration curves, within the permissible range. Toluene was the most abundant VOC in the ambient air both in residential and industrial areas. Both indoor and outdoor air concentrations of all target VOC except benzene were higher in residential area near the DIC compared to that further away from the DIC. Moreover, the ambient air concentrations of all target VOC except benzene for two industrial sites (A and B) were significantly higher than the outdoor or indoor air concentrations in the two residential areas. The findings further suggested that VOC ambient levels measured in a residential area near the DIC be used as a potential indicator of odor-causing unidentified air pollutants transported from the DIC. Moreover, it was found that the elevated ambient toluene levels outweighed the indoor sources with respect to the environmental exposure of residents nearby the DIC. However, in the residential area further away from the DIC, the toluene indoor sources outweighed the outdoor sources.

• Journal of Environmental Impact Assessment
• /
• v.14 no.3
• /
• pp.109-115
• /
• 2005

This study was conducted to evaluate the efficiency of indoor air cleaners and to inform how to select them correctly to the users. The efficiencies of removing suspended bacteria per hour were $64.3{\pm}13.1%$ for filter, wet, and complex type, respectively, which showed the complex type was the most efficient. The removal efficiencies of formaldehyde (HCHO) after two hours operation of air cleaners showed 88.3% and 81.1% for filter and wet type, respectively. The efficiency of complex type, with removal rate of 55.5~58.4%, was decreased after 30 minutes operation. Therefore, it is recommended to perform over 60 minutes when doing air cleaner certification test for HCHO removal efficiency. Generally, air cleaners having low wind volume showed higher efficiency. All tested air cleaners had no potential for removing of volatile organic compounds (VOCs), which is toxic substances, and it is desirable to develop a device which can control these substances. The results also confirmed that there was no ozone production from all tested air cleaners. And it is recommended to ventilate for 20 minutes every four hours to maintain 50% ventilation status.

• YAKHAK HOEJI
• /
• v.43 no.3
• /
• pp.369-377
• /
• 1999

A new series of highly water soluble platinum(II) complexes {Pt(II)[1,3-bis(phenylthio) propane](trans- -1,2-diaminocyclohexane) (PC-1) and Pt(II)[1,3-bis-(phenythio)propane] cis-1,2-diaminocyclohexane(PC-2)} were synthesized, and characterized by their elemental analysis and by various spectroscopic techniques[infrared(IR), 13C-nuclear magnetic resonance (NMR)]. In vitro antitumor activity of new Pt(II) complexes was tested against P-388 and L-1210 mouse lymphocytic leukemia cell lines, PC-14 / P, PC-14/ADM and PC-14 / CDDP human pulmonary adenocarcinima, DU-145 human prostate carcinoma, HT-1376 human bladder carcinoma, ZR-75-1 human breast carcinoma, MKN-45/P and MKN-45/CDDP human gastric adenocarcinoma cell lines using colorimetric MTT[3-(4,5-dimethyl thiazol-2-yl)-2.5-diphenyltetrazoliumbromide] assay for cell survival and proliferation. PC-1 showed active against L-1210, P-388 leukemia, human lung, stomach, prostate, bladder and breast cancer cell lines, and the antitumor activity of these compounds were comparable or superior to those of PC-2 and displatin. The nephrotoxicities of PC-1 and PC-2 were found quite less than that of cisplatin using MTT and [3H] thymidine uptake in rabbit proximal tubule cells and human kidney cortical cells. Based on these results, this novel platinum (II) complex compound (PC-1) represents a valuable lead in the development of a new anticancer chemotherapeutic agent capable of improving antitumor activity and low nephrotoxicity.

• Polymer(Korea)
• /
• v.39 no.2
• /
• pp.261-267
• /
• 2015

The inclusion complexes (ICs) between polylactic acid (PLA) and ${\beta}$-cyclodextrin (CD) were prepared by co-precipitation method in this work. The orthogonal experiments were designed to investigate the influence of different factors on the formation of inclusion complexes. The results suggested that the optimum scheme of inclusion compounds could be obtained when the feeding ratio of CD to PLA (wt%) was 20:1, stirring speed was 6 kr/min and the stirring time was 30 min. The structures and properties of the inclusion complexes were characterized by $^1H$ NMR, FTIR, DSC, FT-Raman, XRD and TGA. The DSC results demonstrated that the crystallization behavior of the inclusion complexes nearly disappeared. It was found that ${\beta}$-CD-PLA inclusion complex had a better thermal stability compared with the neat PLA. The model of the inclusion complexes was proposed on the basis of XRD, $^1H$ NMR and DSC results.

• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.5
• /
• pp.741-750
• /
• 2011

A pilot-scale biofilter was constructed to discover degradation characteristics of the complex odor discharged from Ansan wastewater treatment plant. Candida tropicalis for volatile organic compounds, sulfur oxidizing bacteria(SOB) for hydrogen sulfide, and bacteria extracted from feces soil were immobilized on a polymer gel media. According to this study, the EBCT was varied from 36 sec to 18 sec. Toluene was removed as 80% along the variations, but it was recovered as 100% within 1 week. All benzene and xylene were removed during the operation while the efficiency of hydrogen sulfur was temporary decreased at 18 sec of EBCT, thereafter it was recovered to 100% within a week. The maximum elimination capacities of the benzene, toluene, xylene, and hydrogen sulfur were 6.6 g/$m^{3}$/hr, 31.7 g/$m^{3}$/hr, 7.8 g/$m^{3}$/hr, and 133.6 g/$m^{3}$/hr, respectively. There were merits on removal both organic and inorganic complex odor using the pilot-scale biofilter embedded with microorganisms immobilized on polymer gel media.

• Journal of the Korean Chemical Society
• /
• v.33 no.1
• /
• pp.106-112
• /
• 1989

Liquid phase oxidation of tetralin with clean air were carried out utilizing complexes composed of various heterocyclic base and CrO$_3$ in N,N-dialkylamides. In the CrO$_3$-N,N-dialkylacetamide complex catalyzed oxidations of tetralin at 90$^{\circ}$C, the maximum conversion of tetralin to the products and selectivity of ${\alpha}$-tetralone were 35.2% and 96.1%, respectively. Under this condition, however, negligible amount of ${\alpha}$-tetralol was determined.

• Journal of the Korean Society of Industry Convergence
• /
• v.9 no.2
• /
• pp.111-116
• /
• 2006

This study provides the optimal conditions treating with the coagulation process and the other chemical treatment processes for dyeing wastewater, especially various dyeing complex wastewater. The results are shown as follows: 1. Optimum reaction condition of pH for ferrous sulfate was the range of 9 to 12. And when 3,000ppm(mg/l) of ferrous sulfate was dosed, the maximum $COD_{Mn}$ removal rate was approximately 40%. 2. In case of ferrous chloride and Bittern as coagulants, optimum pH range was 10 to 11. And maximum $COD_{Mn}$ removal rate was approximately 46% to 50% for dose of 2,000ppm(mg/l) to 6,000 ppm. 3. It is confirmed that the activated sludge process following coagulation precipitation method provides better treatment efficiency than the coagulation precipitation method following the activated sludge process. 4. The purpose of this study was to produce CGF (Cyanoguanidineformaldehyde resin) by organic compounds. 5. The complex coagulation agent by this study is the most economical coagulant with Alum(aluminum sulfate) and the removal efficiency is approximately 54% with 1,000ppm(mg/l) of pH range 6 to 7.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.8
• /
• pp.541-548
• /
• 2012

The objective of this study was to investigate emission characteristics of odorous compounds from the pneumatic waste collection plants (namely, A and B sites). The air samples were collected from each site, at a carrier gas inside the plant and an exhaust gas, to analyze complex odor and 22 odorous compounds. Ammonia, sulfur compounds, and acetaldehyde were the critical odorous components generated in the plants studied. Characteristics of odor at exhaust outlet varied according to the type of odor control engineering. In the analysis of the odor contribution degree of odor components based on odor threshold, site A shows that the odor contribution of dimethyl sulfide was found to be 26%, acetaldehyde 18%, and methyl mercaptan 14%. For site B, methyl mercaptan was 56% and both hydrogen sulfide and dimethyl sulfide were 15%.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.6
• /
• pp.821-832
• /
• 1997

The aim of this study was to separate or purify some bioactive compounds from flowers of alfalfa(Medicago sativa L.) and to test of the isolated compounds on alfalfa for their autotoxicity and on Echinochloa crus-galli for their allelopathy for seed germination and seedling weight. Using thin layer chromatography(TLC) of $CHCl_3$ extracts, the most inhibitory band to alfalfa seed germination was determined. Germination inhibition of this extract suggested a complex chemical interaction. Separation and purification of compounds with CHCl$_3$ extract of fresh alfalfa flowers were conducted by a silica gel TLC, and microcrystalline cellulose TLC(MCTLC), followed by droplet countercurrent chromatography(DCCC) bioassay. Preliminary identification was done by high perfomance liquid chromatography(HPLC) on the most inhibitory fractions in DCCC. Ferulic acid, caffeic acid, vanillic acid, rutin, narringin were identified in fraction 5 and ferulic acid, caffeic acid, vanillic acid, rutin, coumarin in fraction 6. The phytotoxicity of their individual compound was tested on alfalfa and Echinochloa crus-galli seed germination and seedling weight. Coumarin and ferulic acid showed the most inhibitory effect on alfalfa seed germination and Echinochloa crus-galli seedling fresh and dry weight. These compounds may be, at least in part, involved in autotoxicity and allelopathy.