• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.33.1-33.1
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• 2011

Strontium doped lanthanum manganite (LSM) with perovskite structure for SOFC cathode material shows high electrical conductivity and good chemical stability, whereas the electrical conductivity at intermediate temperature below $800^{\circ}C$ is not sufficient due to low oxygen ion conductivity. The approach to improve electrical conductivity is to make more oxygen vacancies by substituting alkaline earths (such as Ca, Sr and Ba) for La and/or a transition metal (such as Fe, Co and Cu) for Mn. Among various cathode materials, $LaSrMnCuO_3$ has recently been suggested as the potential cathode materials for solid oxide fuel cells (SOFCs). As for the Cu doping at the B-site, it has been reported that the valence change of Mn ions is occurred by substituting Cu ions and it leads to formation of oxygen vacancies. The electrical conductivity is also affected by doping element at the A-site and the co-doping effect between A-site and B-site should be described. In this study, the $La_{1-x}Sr_xMn_{0.8}Cu_{0.2}O_{3{\pm}{\delta}}$ ($0{\leq}x{\leq}0.4$) systems were synthesized by a combined EDTA-citrate complexing process. The crystal structure, morphology, thermal expansion and electrical conductivity with different Sr contents were studied and their co-doping effects were also investigated.

• The Journal of the Korea Contents Association
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• v.9 no.7
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• pp.225-232
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• 2009

This study conducted the following experiment to examine effects of cardiovascular function on lumbar stabilization exercise(LSE) in floor or swiss ball. This experiment was conducted to compare heart rate, systolic blood pressure, diastolic blood pressure and peripheral vascular oxygen saturation effects by lumbar stabilization exercise in floor or swiss ball with 18 normal adult and it divided 9 subjects. experiment group (1) is applying LSE on floor group and (2) is applying LSE on swiss ball group. Heart rate was measured by portable heart rate manometer, blood pressure was measured by hemodynamometer, and peripheral vascular oxygen concentration was measured using a computerized NURYTEC measuring apparatus analysis. These result lead us to the conclusion that systolic blood pressure and peripheral vascular oxygen concentration were influenced by LSE. but there was not differential effect between each groups. These results suggest that LSE has the capability to improve heart rate, blood pressure, peripheral vascular oxygen concentration. Consequently, LSE would be lead to increment of cardiovascular function.

• The Journal of the Korea Contents Association
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• v.6 no.10
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• pp.1-8
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• 2006

The new system evaluating the pollution of the water quality for the branches of geum river using the fuzzy integral was proposed in this study. In this paper, the five individual factors, such as BOD(biochemical oxygen demand), COD(chemical oxygen demand), SS(suspended solids), T-N(total nitrogen), and T-P(total phosphorus) are selected. The measurement of fuzzy integral was determined depending on the degree of how they affect the pollution of water quality. The real values for the five factors measured and obtained from the branches of the geum river was normalized to ranging from 0 to 1. Finally, using the fuzzy integral, the degree of the pollution for the branches of geum river was expressed as the real numerical number. As a result, it appears that this approach can be proposed as the new system evaluating the pollution of the water quality for the branches of the geum river.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.1
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• pp.46-51
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• 2004

The film coated snap bean (Phaseolus vulgaris) seeds with five different coating materials treated with 3% increase in seed weight were planted at sandy loam soil controlled moisture content of 18, 19, 20 and 21 %. The oxygen diffusion rate (ODR) was calculated from the different moisture content soil. The number of normal seedlings, seedling vigor, and seedling capability in field (seed vigor x dry matter weight) were observed at 9 days after planting and compared to the changes of ODR. The germination rate and ODR were sharply decreased simultaneously in the seeds planted at 21 % soil moisture content. Seedling emergence did not occur at all as the soil moisture content increased above 22 %. Hence this value should be considered as the threshold of soil moisture content for seedling emergence. An ODR value under 20% did not influence the percent emergence significantly. The certain difference observing in the emergence at the same ODR was not related clearly to the condition of soil. So it can be assumed that the limit of soil moisture content for the emergence of snap bean was approximately 20%. The value of 18% soil moisture content may be considered as the optimum for snap bean emergence. There was close relationship between the mean value of ODR in different soil moisture contents and the emergence. The germination rates of the seeds coated with the different materials were quite different when the seeds were planted at 21 % soil moisture. Dry weight of the seedlings from film coated seeds was decreased slightly, but the germination rates were not much different from the non-treated control under relatively higher soil moisture content (21 %). Major factor lowering emergence rate was oxygen stress while film coating act as a minor constraint for snap bean sown in excess soil moisture condition.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.42-47
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• 2015

While the oxygen content of gasoline for automobiles in Korea is regulated to less than 2.3 weight %, European and World-Wide Fuel Charter (WWFC) regulate it to less than 2.7 weight %. The oxygen content of oxygen-containing materials increases the octane number of the fuel due to the secondary combustion in the internal combustion engine. It has been reported to be effective in reducing emissions, such as CO, HC, which is caused by incomplete combustion. Before 2000s in the United States and Europe, there has been many researches about vehicle application of the changes in oxygen content of gasoline. However, there are not many domestic researches which reflect the improvement of the fuel quality and automotive technology. In this study, fuels of three different oxygen contents were applied to GDI and MPI engines. As a result, the changes of fuel consumption and emission gas were very similar depends of the oxygen content changes. The PN in GDI engine was decreased as the oxygen content was increased.

• Biomedical Science Letters
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• v.12 no.1
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• pp.49-52
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• 2006

To elucidate the effect of antioxidant complex containing $\beta-carotene$, vitamin E, vitamin C, Ginkgo Biloba leaf extract and selenium on oxygen :tree radical production and detoxification system, rats were fed normal diet and normal diet with antioxidant complex 0.1%, 0.3% and 0.5% for 3 weeks. Feed efficiency ratio, changes in body weight, weight gain and amounts of feces of rat are similar in four groups. Liver weight per body weight and hepatic lipid peroxide weight increased in 0.5% group. However, hepatic glutathione contents in all antioxidant complex added groups were significantly increased compare with normal control group. On the other hand, the activity of xanthine oxidase was a little increased due to the amounts of antioxidant complex. Superoxide dismutase and gutathione peroxidase activity of 0.1% antioxidant complex added group were increased about $10{\sim}20%$ in comparison to normal control group. These results suggest that the supplementation of antioxidant complex 0.1% to basal diet may reduce the hepatic damage caused by free radicals.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.5
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• pp.351-354
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• 2013

Thin-film transistors(TFTs) with silicon-zinc-tin-oxide(SiZnSnO, SZTO) channel layer are fabricated by rf sputtering method. Electrical properties were changed by different annealing treatment of dry annealing and wet annealing. This procedure improves electrical property especially, stability of oxide TFT. Improved electrical properties are ascribed to desorption of the negatively charged oxygen species from the surfaces by annealing treatment. The threshold voltage ($V_{th}$) shifted toward positive as increasing Si contents in SZTO system. Because the Si has a lower standard electrode potential (SEP) than that that of Sn, Zn, resulting in the degeneration of the oxygen vacancy ($V_O$). As a result, the Si acts as carrier suppressor and oxygen binder in the SZTO as well as a $V_{th}$ controller, resulting in the enhancement of stability of TFTs.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.6
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• pp.816-826
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• 1998

The effects of rice bran oil on the characteristics of performance and exhaust emissions have been experimentally examined by a single cylinder four cycle direct injection water-cooled and agricultural diesel engine operating at several loads and speeds. The experiments are conducted with light oil blends of rice bran with light oil and rice bran oil as a fuel. The fuel injection timing if fixed to $22^{\circ}$ BTDC regardless of fuel type engine loads and speeds. Any oxygen is not included in light oil while the oxygen contents of 10.7% are included in rice bran oil. The lower calorific value of rice bran oil is less than light oil and the viscosity is very high compared with light oil. In pre-sent study it is found that these major differences of chemical and physical properties control the combustion parameters that affect the performance and exhaust emissions of diesel engines using a rice bran oil as fuels.

• Analytical Science and Technology
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• v.23 no.6
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• pp.615-618
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• 2010

An oxygen bomb combustion procedure were studied for determination of heavy metal in polymer materials such as polyvinyl chloride and polypropylene by ICP-AES. This method is proposed as a rapid and simple sample preparation for decomposition of polymer containing certified contents of the analytes by teflon coated oxygen bomb combustion using different absorbing solution. The recoveries of metal were found to be 30~102% from absorbed solution by ICP-AES method using polypropylene certified reference material(PP CRM-As, Ba, Cd, Hg, Pb, Zn). The recoveries of metal using PVC CRM(Cd, Hg, Pb) was found to be 45 ~101% with same procedures.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.361-364
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• 2002

This study was performed to establish a simple and accurate method for the determination of oxygen that is a processing aid in various beverage. The quantitative determination of dissolved oxygen (DO) contents in 30 cases of samples were performed by traditional titration method and polarography. As a result of the study, the analysis of DO contents in fruit-extract beverages containing oxygen by titration method was time consuming and large sample volumes were needed. Besides, serious interferences with compounds such as hydroxylamine and nitric oxide were observed, leading to false response. Although the polarography is easily affected by $H_2S$, proteins, and various organic compounds, it is a simple and practical method that provides inexpensive and relatively rapid analysis. The polarography is best suited to the routine determination of DO in a large number of samples and it is expected that the polarography can directly be applied to the quality control of the beverages containing added oxygen. The analysis results of DO contents in various fruit-extract beverages with oxygen and without oxygen were as follows: 23.10 ppm to 32.60 ppm for various frutis extract beverages with oxygen, 0.70 pp to 2.54 ppm for mixed beverages without oxygen, 7.63 ppm to 8.28 ppm for drinking water.