• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.319-324
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• 2013

The partial oxidation reaction of methane was investigated to produce syngas with $Ni/CeO_2-ZrO_2$, $Ni-Ru/CeO_2-ZrO_2$ and $Ni-Pd/CeO_2-ZrO_2$ catalysts. Honeycomb metallic monolith was applied in order to obtain high catalytic activity and stability in partial oxidation reforming. The catalysts were characterized by XRD and FE-SEM. The influence of various catalysts on syngas production was studied for the feed ratio (O/C), GHSV and temperature. Among the catalysts used in the experiment, the $Ni-Pd/CeO_2-ZrO_2$ catalyst showed the highest activity. The 99% of $CH_4$ conversion was obtained at the condition of T=$900^{\circ}C$, GHSV=10,000 $h^{-1}$ and feed ratio O/C=0.55. It was confirmed that $H_2$ yield increased slightly as O/C ratio increased, while CO yield remained almost constant. Also, $CH_4$ conversion decreased as GHSV increased. It was found that the safe range of GHSV for high $CH_4$ conversion was estimated to be less than 10,000 $h^{-1}$.

• Polymer(Korea)
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• v.32 no.6
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• pp.509-515
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• 2008

The aminated polypropylene melt blown ion exchange fibers were synthesized with acrylic acid monomer onto polypropylene melt blown fibers by radiation-induced polymerization and subsequent amination. Degree of grafting was increased with increasing the acrylic acid monomer concentration and total dose. The highest degree of grafting was obtained 140% at a monomer concentration of 20 v/v% acrylic acid and total dose of 4 kGy. Optimum condition of Mohr's salt was 5.0 $\times10^{-3}$ M. Degree of amination was increased with increasing degree of grafting. Water content was about 1.5 times higher than that of trunk polymer. The maximum ion-exchange capacity was 7.3 meq/g which was 2$\sim$3 times higher than a commercial ion exchange fiber. The average pore size was decreased and BET surface area was increased in order of PPmb, PPmb- g- AAc and APPmb- g- AAc. The average pore size and BET surface area of synthesised fibers were $366.1\;{\AA},\;3.71m^2/g,\;143.3\;{\AA},\;4.94m^2/g,\;40.97\;{\AA},\;8.98m^2/g$, respectively.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.629-637
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• 2021

To develop a safer cosmetic preservative, we carried out a comparative study on characteristics of OD and OD-gal, where OD-gal was synthesized from OD using E. coli β-gal. OD-gal synthesis was confirmed by mass spectrometry analysis as sodium adduct ion (m/z=331.1731) and protonated ion (m/z=309.1926) of OD-gal. To compare the antimicrobial activities of OD and newly synthesized OD-gal, MIC values were investigated using E. coli, S. aureus, C. albicans, and A. niger. As a result, it was observed that there was no remarkable difference between MIC values of OD and OD-gal. In addition, to compare the cytotoxicity of OD-gal and OD, HaCaT cells were treated with OD or OD-gal, and then cell viability was quantified using EZ-Cytox assay. In the case of 1.5% OD, the cell viability was 64% at 24 h and 42% at 48 h compared to the control, and cell viability of 1.5% OD-gal-treated cells showed no significant change at 24 h and was 85% at 48 h. Consequently, the cytotoxicity of OD-gal-treated cells was reduced by more than 40% when compared with that of OD-treated cells. Thus, the newly synthesized OD-gal in this study is safer than the existing OD used as a cosmetic additive. In the future, OD-gal will be applicable as a substitute for OD as a less toxic preservative for the cosmetic industry.

• Journal of Life Science
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• v.19 no.4
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• pp.538-542
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• 2009

In this study, we confirmed water content and oxygen permeability of new polymeric materials synthesized from itaconic acid used for soft contact lenses. In this study, we polymerized materials for soft contact lenses using HEMA (2-hydroxyethyl methacrylate), the based-monomer of soft contact lenses, EGDMA (ethylene glycol dimethacrylate) as a cross linkage agent, and the new additives mono-ester or di-ester derived from itaconic acid commercially produced by the fermentation of A. itaconicus. New polymer materials for contact lenses were synthesized with the mixture of HEMA and mono- or di-ester at different ratios and water content and oxygen permeability (Dk) was analyzed. In polymerizing HEMA and mono-ester (15%), the water content and oxygen permeability of contact lenses were found to be of good value at 57.7% and 28.6 Dk respectively. The mixture of HEMA and mono-ester is more excellent than HEMA/di-ester in regards to water content and oxygen permeability. The water content and oxygen permeability of soft contact lenses made by new polymeric materials were highly represented.

• Journal of Soil and Groundwater Environment
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• v.11 no.4
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• pp.18-24
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• 2006

The possibility of multiresidue analysis of 24 pesticides out of 30 residual pesticides which are subjected to test in the golf courses was examined. The utility of multiresidue method for pesticide residue test was evaluated by recovery test through a standard addition method of pesticides in water, soil, and lawn grass. The experimental results of the recovery test for individual pesticides are as follows : The number of pesticide of which average recovery rate was over 70% regardless of media was 16 pesticides. These pesticides were composed of 8 organophosphorus pesticides (chlorpyrifos, chlorpyrifosmethyl, diazinon, EPN, fenitrothion, phenthoate, phosalone, and toclofos-methyl). 4-organochlorinated pesticides (daconil, captan, endosulfan, and tetradifon), 2-pyrethroid pesticides(fenpropathrin, lambda-cyhalothrin) and 2 other pesticides (bromopropylate, pendimethalin). On the other hand, in case of dicofol, average recovery rate was over 70% for water and lawn grass but only 53.3% for soil. Therefore, the multiresidue method applied in this experiment is not appropriate for analysis of dicofol in soil. Furthermore, among 7 pesticides, 2 pesticides(amitraz and pyraclofos) showed that theirs average recovery rate deviated from criteria($70{\sim}130%$) in almost ail media, while 5 pesticides(bensulide, deltamethrin, iprodione, phosphamidon and tralomethlin) were not detected from all media by GC/NPD or GC/ECD.

• Korean Journal of Agricultural Science
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• v.29 no.1
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• pp.32-43
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• 2002

The peach pyralid moth (Dichocrocis punctiferalis) is reported as import ant pest insect to chestnut fruits in Asia including Korea. For seasonal occurrence of D. punctiferalis in 1996, 1998 and 1999, D. punctiferalis adults were collected by light trap and sex pheromone wing trap in the chestnut orchard. Also, damaged rate of chestnut fruits were examined each collecting site. In 1996, according to examination by using light trap at three different site in Kongju, the occurrence peak of 2nd gene ration of D. punctiferalis adults was early August. Collected individuals after September were cons ide red as 3rd generation. Damaged rate due to maturation type was 26.5% averagely. The order of damaged rate were early, late and middle maturation type as 35.04%, 19.35% and 26.03%, respectively. Using synthetic sex pheromone trap at Kongju, Cheungyang and Buyeo in 1998, occurrence peaks were occurred mid-August to 2nd generation and late September to 3nd gene ration in Kongju. However, from early-August to late-September 5 peaks were occurred sequentially in Cheungyang. Second generation adults were occurred in mid-August and 3rd ones were occurred from late-September to early-October in Buyeo. In 1999, occurrence peaks of 3rd generation were early, middle and late September in Kongju, Cheungyang and Buyeo respectively. Damaged rate were 6.8%, 6.6% and 15.3% in Kongju, Cheungyang and Buyeo, respectively. Damaged rate order due to variety were Eunki, Chukpa, Danpa, Bokpa, Wangjung, Byunggo57, Yuoma at Buyeo and were Chukpa, Dukmyung, Byunggo57 at Cheungyang in 1999. Damage rate of chestnut were different with variety. Eunki and Chukpa in Buyeo and Chukpa and Dukmyung in Cheungyang were more damaged by D. punctiferalis respectively.

• Journal of Yeungnam Medical Science
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• v.12 no.2
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• pp.269-281
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• 1995

The effect of persistant mild hyperglycemic hyperinsulinemia on the development of the insulin resistance in rats was studied in vivo. Also, the characteristics of the insulin resistance compared with the insulin resistance of STZ diabetic rats. Persistant mild hyperglycemic hyperinsulinemic rat model was produced by ingestion of glucose polymer for 8 days. The glucose disappearance and infusion rate was measured by hyperinsulinemic euglycemic clamp technique at steady state of blood glucose and insulin levels. The clamped level of blood glucose was 100 mg/dl, and the clamped levels of insulin were $70{\mu}U/ml$ (physiologic condition) and $3000{\mu}U/ml$ (supramaximal condition). Hepatic glucose producticon rate was calculated using measured data. And the glycogen synthetic capacity of skeletal muscle(soleus) and liver was measured after 2 hours of hyperinsulinemic euglycemic clamp study. The glucose disappearance and glucose infusion rate in glucose polymer group was decreased in the both physiological and supramaximal insulin level compared to the rate of the normal control group. The rate of STZ diabetic group wase lowest at supramaximal insulin level among two another experimental groups. The hepatic glucose production rate of glucose polymer group was decreased compared to normal control but increased in STZ diabetic group. The glycogen synthetic capacity of skeletal muscle and liver of glucose polymer group was not significantly different from normal control group, but it was markdly decreased in STZ diabetic group. These results suggest that persistant mild hyperglycemic hyperinsulinemia may induce insulin resistance, but glycogen synthetic capacity is intact.

• Journal of Convergence for Information Technology
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• v.11 no.5
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• pp.199-205
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• 2021

This study was done to evaluate the dermatoxicity of zinc sulfate (ZnSO4) and the protective effect of Rubus parvifolius L. (RP) extract on cytotoxicity of ZnSO4, mordant in cultured SK-MEL-3 cells. For this study, it was done an antioxidative effect as DPPH-radical scavenging ability as well as the diminutive ability of total melanin with cell viability. ZnSO4 significantly decreased cell viability in dose-dependently, and it was mid-toxic. The ascorbic acid significantly increased cell viability damaged by ZnSO4-induced cytotoxicity. In the protective effect of RP extract on ZnSO4-induced cytotoxicity, RP extract significantly increased cell viability compared with ZnSO4-treated group, and also it showed both the DPPH-radical scavenging ability and the decrease of total amount of melanin. From these findings, the cytotoxicity of ZnSO4 is correlated with oxidative stress, and also RP extract effectively protected ZnSO4-induced cytotoxicity via antioxidative effect such as DPPH-radical scavenging ability with the whitening effect by the decrement of total amount of melanin. Conclusively, the natural ingredients like RP extract may be a useful agent for the improvement of antioxidative and whitening effects

• Clinical and Experimental Pediatrics
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• v.45 no.6
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• pp.732-742
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• 2002

Purpose : In order to evaluate the hypoxia-ischemia(H-I) induced neurotoxicity and the protective effect of xanthine oxidase(XO) inhibitor(allopurinol), cell number, cell viability, lactate dehydrogenase(LDH), protein synthesis(PS) and protein kinase C(PKC) activity were measured in cerebral neurons and astrocytes. Methods : Cytotoxic effect was measured by in vitro assay at 12-72 hours after H-I on cerebral neurons and astrocytes derived from 7-day old neonatal rats which were subjected to unilateral common carotid artery occlusion and exposed to hypoxic condition for 3 hours. The protective effect of XO inhibitor was examined by the cell number, cell viability, LDH and PS on 14 days after H-I with allopurinol intraperitoneal injection 15 minutes prior to H-I. In addition, the effect of allopurinol on PKC activity in hypoxic conditions was examined in neurons. Results : 72 hours from H-I, the cell numbers and viability were decreased significantly in time-dependent manner on neurons and those of astrocytes also decreased slightly, compared with control. In neonatal rats treated with H-I, the cell number, cell viability, and PS in neurons were decreased, but LDH was increased significantly compared with control. In neonatal rats pretreated with allopurinol, the cell number and viability, and PS in neurons were increased and LDH was decreased significantly compared with H-I. PKC was increased remarkably after hypoxic condition. But PKC was decreased significantly against hypoxic condition after allopurinol pretreatment. Conclusion : From these results, it is suggested that H-I is more toxic in neurons than astrocytes and allopurinol is very protective with increasing of PS, and decreasing of LDH and PKC in neurons from hypoxic-ischemic condition.

• Korean Journal of Plant Resources
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• v.22 no.5
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• pp.467-472
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• 2009

This study was conducted to break down the self-incompatibility of Astragalus membranaceus Bunge by old-flower pollination, NaCl and $CO_2$ treatment. The old-flower pollination in green house produced fertilization during the 1st and 2nd day after flowering from early September to early October, but almost no fertilization in late August. The most successful pollination occurred in late September at the 1st day after flowering when pod setting was 33.3% and that of seed set was about 86.2%. The old-flower pollination in field showed pod setting for the control group from late August to early October, but no seed set except the days of mid-September and late September. The most successful pollination occurred in late September during the 2nd day of flowering when the percentage of pod setting was 39% and that of seed set was 94.9%. The wrapping in field set pods from late August to early October, but did not set seeds except in mid and end of September. The percentage of pods was 39% and percentage of seeds was 94.9% about flowering after first day in end of September. by field culture. The best result from NaCl treatment was achieved when 1% NaCl treatment in green house produced 21.3% of pod setting in early October and 66.7% of seed set in late September. In field, NaCl 5% treatment produced best result with 7.3% of pod setting and 90.9% of seed set in mid-September. No differences were observed between the $CO_2$ 700ppm treatment and the control group.