• Membrane Journal
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• v.28 no.3
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• pp.169-179
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• 2018

The purposes of this paper were to improve both fouling and chlorine resistance by increasing the hydrophilicity of the reverse osmosis membrane. In order to improve chlorine resistance, the surface of RO membrane was activated by ultraviolet irradiation, and then it was modified by the sol-gel method using Octyltriethoxysilane (OcTES) such as the silane coupling agent to low sensitivity to chlorine, thereby the polyamide active layer was protected and chlorine resistance was improved. In addition, polyglycerol polyglycidyl ether (PGPE) and sorbitol polyglycidyl ether (SPE) coating with different number of epoxides, ring opening reaction of epoxide improved the anti-fouling resistance. The surface modification condition was optimized by FT-IR, XPS, and contact angle analysis. As a result, the permeability reduction rate of the silane-epoxy modified membrane after the fouling test was decreased about 1.5 times as compared with that of the commercial membrane. And the salt rejection was maintained over 90% at $20,000ppm{\times}hr$ even after chlorine resistance test.

• Korean Journal of Environmental Agriculture
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• v.2 no.2
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• pp.73-77
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• 1983

Principle of steam distillation has been successfully applied to the routine extraction of organochlorine pesticide residues from soil samples. Recovery of 8 organochlorine insecticides was found consistent and also comparable to that of conventional solvent extraction method. Recoveries of ${\alpha}-BHC$ and heptachlor was, however, rather poor at 47 and 45% respectively. The steam distillation method offers added advantages such as economy in time and costly solvents.

• Fisheries and Aquatic Sciences
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• v.20 no.9
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• pp.22.1-22.6
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• 2017

The antihyperlipidemic and antioxidant activities of dietary supplementation of sea tangle from Goseong and the alginate-free residue of sea tangle were investigated in Sprague Dawley rats treated with a high-fat diet, streptozotocin, poloxamer 407, and bromobenzene. The alginate-free residue of Goseong sea tangle induced a significant reduction in triglycerides and total cholesterol levels, as well as a significant increase in high-density lipoprotein cholesterol levels. Alginate-free Goseong sea tangle residue reduced the activities of the phase I enzymes aminopyrine N-demethylase and aniline hydroxylase, which had been increased by intraperitoneal injection of bromobenzene. Pretreatment with Goseong sea tangle residue prevented a bromobenzene-induced decrease in epoxide hydrolase activity. Bromobenzene reduced hepatic glutathione content and increased hepatic lipid peroxide levels. Pretreatment with alginate-free Goseong sea tangle residue prevented lipid peroxidation induced by bromobenzene, but pretreatment with Goseong sea tangle did not. These results suggest that Goseong sea tangle residue exerted antihyperlipidemic and antioxidant activities that were higher than those induced by alginate-containing sea tangle. Therefore, the alginate-free residue may contain physiologically unknown active components, other than alginic acid, which may potentially be used to prevent hyperlipidemic atherosclerosis.

• The Journal of Korean Medicine
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• v.16 no.2 s.30
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• pp.320-336
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• 1995

SANGNYANGHYOLTANG(SYT) is one of the most important prescription that has been used in oriental medicine for diabetes mellitus. The sudy was done in order to elucidate the anti-diabetic effect of SYT. After pretreatment of SYT(1,000mg／kg) for 6 weeks, the effect of of SYT was prevented on serum liver function test and hepatic lipid peroxide content in rats i.v. injected with streptozotocin(STZ, 50mg／kg, tail vein) 5 weeks after pretreatment of SYT. The hepatic microsomal cytochrome P-450 and aniline hydroxylase were significantly decreased, and aminopyrine N-demethylase activity was significantly increased in SYT-STZ group as compared with control group. Changes in aldehyde oxidase, xanthine oxidase, superoxide dismutase, catalase, epoxide hydrolase, UDP-glucuronyltransferase and sulfotransferase activities were not significantly different in any of the group. The cytosolic glutathione S-transferase activity was significantly decreased in SYT-STZ group as compared with control group. The selenium-independent glutathione peroxidase was significantly increased in SYT-STZ group as compared with control group, but there was no significant difference in selenium-dependent glutathione peroxidase in any of the groups. The hepatic glutathione concentration was significantly increased in SYT-STZ group as compared with control group, and ${\gamma}-glutamylcystein$ synthetase and glutathione reductase activities were not significantly different in any of the groups. The hepatic lipid peroxide content, serum aminotransferase and sorbitol dehydrogenase activities were slightly decreased in significantly in SYT-STZ groups.

• Journal of Ginseng Research
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• v.13 no.1
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• pp.37-41
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• 1989

Reactive metabolites generated by benzo(a)pyrene(BP) monooxygenase(AHH) interact with nucleophiles in DNA and cause mutation and carcinogenesis. We studied the effect of Panax ginseng C.A. Meyer, which induce epoxide hydratase(EH) activity without concomitant induction of AHH activity, on the binding of BP metabolites to DNA in uitro in Sprague Dawley rats. DNA-BP metabolite adducts can be resolved into at least five distinct peaks by elution of a Sephadex LH-20 column with a water methanol gradieNt. These peaks are arbitrarily designated A(most polar) through I(least polar). Of the 5 peaks tentatively assigned to 7,8 biol-9,10-oxide(A),7,8·oxide(B),4,5-oxide(C), and further metabolites of 9-OH-BP(D & E), peaks A, C, D, and I were reduced to 70, 85, 80, and 30% of controls, respectively, and there was no significant change in peak B. In connection with this DNA binding study, BP metabolizing enzymes including AHH, EH, demethylase(DM) activity and cyt. P-450 contents were also investigated in order to compare the BP treated control with ginseng and BP treated test groups. The results showed that the EH activity was increased by 139% over the BP control, the Cyt. P-450 content was increased by 180% over the control value, and DM and AHH activities were also increased to some degree for the BP test group, but there was no significant effect of the ginseng treatment.

• YAKHAK HOEJI
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• v.46 no.5
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• pp.358-363
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• 2002

In Oriental medicine, the prescriptions composed of several herb medicines have been used. It is still unclear how the sum of several extracts of anti-thirst drugs represents the anti-lipid peroxidative action. Three anti-thirst herb medicines, Kalopanax pictus (K), Pueraria thunbergiana (P) and Rhus verniciflua (R), were extracted with MeOH and $H_2O$, respectively, and the former one was fractionated into the resultant EtOAc extract. Each extract was reconstituted to give KPR311, KPR131 and KPR113 where, for example, KPR311 represents the complex of K-P-R {3:1:1 (w/w/w)} of the three extracts. The order of the inhibitory effect in bromobenzene-induced lipid peroxidation in rats was as follows: EtOAc extract＞$H_2O$ extract＞MeOH extract. Extract complexes were found to be more potent than the extracts of individual crude drugs. The KPR131 of EtOAc extract was found to be the most potent among the tested samples. These anti-lipid peroxidative effects were also supported by the decrease of aniline hydroxylase activity and aminopyrine N-demethylase activity, on the other hand by the increase of epoxide hydrolase activity. All the tested samples were assayed in vitro antioxidative effects such as DPPH assay, ADP/NADPH/Fe$^{3+}$ assay and ascorbic acid/Fe$^{2+}$ assay. The EtOAc extracts also showed the most significant antioxidative effects. These results suggest that the sum of anti-thirst drugs could reflect the effects of respective crude drugs.s.s.

• Clean Technology
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• v.17 no.4
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• pp.325-328
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• 2011

Atom-efficient preparation of 9, 9'-bis[4-(2'-hydroxy-3'-acryloyloxypropoxy) phenyl]fluorene (3), the extensively used building block for fluorene-containing acrylic epoxy polymers has been described. The epoxide ring opening esterification of 9, 9-bis[4-(glycidyloxy)phenyl]fluorene (1) with acrylic acid was catalyzed by some onium salts such as quaternary ammonium and phosphonium salts. While the coupling reactions depend greatly on the kind of the onium salts, the reaction of 9, 9-bis[4-(glycidyloxy)phenyl]fluorene (1) with acrylic acid proceed most efficiently in the presence of a catalytic amount of tetrabutylphosphonium bromide at $110^{\circ}C$ with 90% yield. This reaction is a cleaner reaction that minimizes the use of reactants and the production of chemical wastes.

• Clean Technology
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• v.17 no.3
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• pp.201-208
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• 2011

The green house gas, carbon dioxide, can be utilized as raw materials to prepare carbon dioxide-based polycarbonates in research and industry. The carbon dioxide-based polycarbonates is one of the emerging low-cost green polymers. Recently, the fast development of carbon dioxide-based polycarbonates has created new chances for industry. In this review, we describe the preparation and characterization of cyclic carbonate monomer using carbon dioxide, oxiranes and oxetanes in the presence of various catalysts and preparation of polycarbonates from cyclic carbonate monomer, presenting an organized and detailed overview of the state of the art.

• Journal of the Korean Chemical Society
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• v.50 no.1
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• pp.53-59
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• 2006

.FAPO-5 molecular sieves were synthesized starting from the same reactant gel at 170 oC using microwave irradiation technique and conventional hydrothermal reaction. The FAPO-5 molecular sieves were characterized by several techniques such as SEM, FTIR, UV/Vis, and ESR. Moreover, the oxidation of styrene over FAPO-5s was carried out, and compared to check the oxidation and epoxidation ability of the two FAPO-5s. FAPO-5 can be obtained easily by microwave irradiation within 15 min at 170oC, whereas FAPO-5 synthesis is completed in 6 h by conventional electric heating, confirming the acceleration about 20 times by microwave technique. There are no appreciable differences between two FAPO-5s in surface area and coordination state of iron. The FAPO-5 synthesized by microwave irradiation shows higher epoxide selectivity in the styrene epoxidation, which may be explained by the higher hydrophobicity of the catalyst.

• Elastomers and Composites
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• v.55 no.1
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• pp.51-58
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• 2020

In this study, the thermal oxidation of raw natural rubber (NR) was investigated under controlled conditions by optical image and fourier transform infrared (FT-IR) analysis. The thermal oxidation was performed on a transparent thin film of raw NR coated on a KBr window in a dark chamber at 80℃ under low humidity conditions to completely exclude moisture and restrict light oxidation. Images of the thin film of raw NR were obtained before and after thermal oxidation. FT-IR absorption spectra were measured in the transmission mode at different thermal exposure times. The thermal oxidation of NR was examined by the changes in the absorption peaks at 3449, 1736, 1447, 1377, 1242, 1072, and 833 cm^-1, which corresponded to a hydroxyl group (-OH), a carbonyl group (-C=O) from an aldehyde and a ketone, a methylene group (-CH₂-), a methyl group (-CH₃), a carbon-oxygen single bond (-C-O) from an epoxide, a carbon-oxygen bond (-C-O) from an ether, an alcohol, a peroxide, or a cyclic peroxide, and a cis-methine group (cis-CCH₃=CH-), respectively. In the initial stage of thermal oxidation, two different types of free radicals were produced quickly and randomly by the homolytic cleavage of a double bond and allylic hydrogen abstraction. Aldehydes and ketones were formed from chain scissions of the double bonds and alcohols were produced from allylic hydrogen abstraction at the methylene or methyl groups. Two reactions seemed to proceed competitively with each other. At a later stage, oxidative crosslinks seemed to dominate through the combination of free radicals such as an allyl radical (CH=CHCH₂·), alkoxy radical (RO·), and peroxy radical (ROO·) and the reaction of a hydroperoxide (-ROOH) with a double bond. The image obtained after thermal oxidation showed hardening without cracks. Based on these observations, a plausible two-step mechanism was suggested for chain hardening caused by the thermal oxidation.