• Journal of Advanced Marine Engineering and Technology
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• v.23 no.3
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• pp.389-397
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• 1999

Recently the use of Pd catalyst have been continued to expand because of cost avaliabilityand performance advantages. Especially the Pd+Rh catalyst instead of the Pt+Rh catalyst had been used for most of three way catalysts because of the more stringent emission standards and its higher temperature effectiveness. The main purpose of this study is to investigate the design parameter impacts on the Pd+Rh cat-alyst for the automotive exhaust catalysts application. This study was investigated on the catalyst efficiency for the volume and the precious metal loading of the Pd+Rh ceramic monolithic cata-lyst. And experiments concerning the effects of volume and precious metal loading on Pd+Rh three way catalysts were conducted to examined the catalyst light-off temperature and conver-sion efficiency on higher volume demonstrated almost similar performance. But their effects on higher precious metal loading demonstrated considerably better performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1137-1141
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• 2007

This paper is concerned with the experimental research of magnetorheological elastomers (MREs). The modulus of the MR elastomers can be controlled by an applied magnet field, so that it can be effectively used for vibration suppression applications. The MR elastomer in this experiment is a mixture of KE-1300 silicone, carbonyl iron powder (300mesh) and a silicone hardener (CAT-1300). Three specimens were manufactured and tested by using the vibration testing instruments. The magnetic field was generated by the permanent magnets. The experimental results show that the natural frequencies of the test article with MR elastomer changes by the applied magnetic field. The performance of the MR elastomer can be increased by stronger magnetic fields. This is under investigation.

• Korean Journal of Plant Resources
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• v.20 no.6
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• pp.544-547
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• 2007

The effects of hwangryun(Coptidis Rhizoma) on lowering lipid and oxidative stress in the induced obesity rat was observed. The concentration of plasma triglyceride in hwangryun treatment groups showed the low values compared to the control group, and as the increased hwangryun, the concentration of triglyceride decreased. The concentration of plasma total cholesterol decreased in all hwangryun treatment groups. However the concentration of plasma HDL-cholesterol and LDL-cholesterol showed no significantly difference in all the treatment groups. Thiobarbituric acid reactive substance(TBARS) concentration in plasma and liver showed low values in all hwangryun treatment groups compared to the control group. Glutathione peroxidase(GSH-Px) and superoxide dismutase(SOD) activities showed no significantly difference in all the treatment groups. However catalase(CAT) activity showed a tendence to increase in hwangryun groups, and in 200mg/kg hwangryun treatment group showed significantly a high value than the control group. Summarizing the results above, hwangryun has the functional materials that lowering lipid and works with oxidative stress.

• Bulletin of the Korean Chemical Society
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• v.23 no.8
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• pp.1135-1138
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• 2002

CuO/ZnO, CuO/SiO,sub>2, and CuO/ZrO2 catalysts were prepared for investigating the support effects on methanol dehydrogenation. It was found that the conversion of methanol was proportional to the copper surface area on Cu/ZnO cat alysts and was independent on that on Cu/ZrO2 and Cu/SiO2. The highest copper surface area was obtained with the Cu/ZrO2 (9/1). The unusual deactivation of the Cu/ZnO, which showed the highest selectivity among the catalysts tested, was observed. Pulse reaction with methanol indicated that the lattice oxygen in ZnO could be removed by forming CO2 in the catalytic reaction, supporting that the ZnO reduction was responsible for the severe deactivation of the Cu/ZnO.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.273-276
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• 2002

Pulse-Coupled Neural Network (PCNN), which can explain the synchronous burst of neurons in a cat visual cortex, is a fundamental model for the biomimetic vision. The PCNN is a kind of pulse coded neural network models. In order to get deep understanding of the visual information Processing, it is important to simulate the visual system through such biologically plausible neural network model. In this paper, we construct the motion detection model based on the PCNN with the receptive field models of neurons in the lateral geniculate nucleus and the primary visual cortex. Then it is shown that this motion detection model can detect the movements and the direction of motion effectively.

• YAKHAK HOEJI
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• v.50 no.1
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• pp.58-63
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• 2006

The antioxidant enzyme (AOE) system plays an important role in the defense against oxidative stress damage. To determine whether myricetin or myricetin/taurine can exert antioxidative effects not only by modulating the AOE system directly but also by scavenging free radical, we investigated the influence of the myricetin and taurine on cell viability ROS level, activities of different antioxidant enzyme, and the expression of different antioxidant enzyme. As results, the cell viability showed inhibition of the proliferation with treatment of 'myricetin' or 'myricetin with taruine', respectively, with dose-dependent manner. Compared to control, the treatment of 'myricetin' decreased activities and gene expressions of superoxide dismutase (SOD), and glutathione peroxidase (GPx). However, combined treatment of 'myricetin with taurine' increased activities and gene expressions of the SOD, GPx, and catalase (CAT). In addition, the combined treatment of 'myricetin with taurine' somewhat decreased ROS levels, compared to the treatment of 'myricetin'. In conclusion, our study provides that the combined treatment of different antioxidants can enhance antioxidant effects.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.54-57
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• 2005

This study examines moisture supplement from the warm ocean in snowfalls of two cases and heavy rainfall of Typhoon case. The QuickSCAT wind is used to evaluate the convergence of moisture fluxes in the storms from the sea in estimation of the amount of heavy snowstorm and rainfall. The results show that enough water vapor transport from ocean to atmosphere induced the severe storms, because strong QuickSCAT -derived vertical velocity nearly concurred with heavy snowfall and rainfall. In the present study, we attempted to show that QuickSCAT wind can be used to forecast the severe weather events, such as heavy snowfall and rainfalls.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.1
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• pp.37-42
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• 1999

The vocal fold has three major function-phonation, respiration and protection, and is richly innervated. The vocal 1314 its autonomic innervation-adrenergic and cholinergic from superior cervical ganglion and the vagus nerve, respectively. The action of both system account for vasoregulation and glandular activity. In e vocal fold several kin of neuropeptides, including SP, CGRP, VIP, TH, NPY, ENK have been reported at the animal including cat or dog. But information regarding the distribution of autonomic nerve fibers containing neuropeptides in the human vocal fold is lacking. Two neuropeptides are of special interest : 1) vasoactive intestinal polypeptide(VIP)that is known to be contained in the parasympathetic(cholinergic) neuron. 2) tyrosine hydroxylase(TH)is located in the cytoplasm of noradrenergic neuron and is the rate-limiting enzyme in noradrenaline synthesis. To understand specific autonomic function of vocal fold we did immunohistochemical examination of VIP and TH in the human vocal fold.

• The Korean Journal of Ecology
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• v.27 no.2
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• pp.107-114
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• 2004

Tomato (Lycopersicon esculentum) seedlings exposed to various concentrations of $CdC1_2$ (0∼100 $\mu$M) in the nutrient solution for up to 9 days were analyzed with the seedling growth, $H_2O_2$ production, glutathione levels and activity changes of enzymes related to $H_2O_2$ removal. The growth of seedlings was inhibited with over 50 $\mu$M Cd, whereas the levels of $H_2O_2$ and glutathione were enhanced with Cd exposure level and time. Meanwhile, Cd exposure increased the activities of catalase (CAT) and glutathione reductase (GR) but decreased the activities of dehydroascorbate acid reductase (DHAR) and ascorbate peroxidase (APX) in both leaves and roots. These results suggest that the altered activities of antioxidant enzymes particularly involved in the $H_2O_2$ removal and the subsequent $H_2O$$_2$ accumulation could induce the Cd-induced phytotoxicity.

• Bulletin of the Korean Chemical Society
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• v.16 no.6
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• pp.504-507
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• 1995

The reaction of Co2(CO)8 with 3,6-di-tert-butyl-1,2-benzoquinone in the presence of the respective 4,4'-chalcogenobispyridine results in the coordination polymers of [CoⅢ(4,4'-X(Py)2)(DBSQ)(DBCat)]n (X=S, Se, Te; Py=pyridine; DBSQ=3,6-di-tert-butylsemiquinone; DBCat=3,6-di-tert-butylcatechol). The title compounds undergo an intramolecular Cat → Co electron transfer, and thus change toward the [CoⅡ(4,4'-X(Py)2)(DBSQ)2]n at elevated temperature. The temperature-switching properties of the compounds directly depend upon the electronegativity of the chalcogen atom of the 4,4'-chalcogenobispyridine coligands. The spectroscopic data disclose that the properties of [CoⅢ(4,4'-S(Py)2)(DBSQ)(DBCat)]n and [CoⅢ(4,4'-Se(Py)2)(DBSQ)(DBCat)]n are similar each other in contrast to those of [CoⅢ(4,4'-Te(Py)2)(DBSQ)(DBCat)]n.