• Biotechnology and Bioprocess Engineering:BBE
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• 제3권2호
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• pp.109-111
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• 1998

The effect of dissolved oxygen concentration on the metabolism of glucose in Pseudomonas putida BM014 was investigated. Glucose was completely converted to 2-ketogluconate via extracellular oxidative pathway and then taken up for cell growth under the condition of sufficient dissolved oxygen concentration. On the other hand, oxygen limitation below dissolved oxygen tension (DOT) value of 20% of air saturation caused the shift of glucose metabolism from the extracellular oxidative pathway to the intracellular phosphorylative pathway. Specific activities of hexokinase and gluconate kinase in intracellular phosphorylation pathway decreased as the DOT increased, while 2-ketogluconokinase activity in extracellular oxidative pathway increased under the same condition. This result can be usefully applied to microbial transformation of glucose to 2-ketogluconate, the synthetic precursor for iso-vitamine C, with almost 100% yield via extracellular oxidation by simple DOT control.

• 한국환경복원기술학회지
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• 제3권1호
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• pp.62-69
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• 2000

Topography influences shallow landslide initiation through both concentration of subsurface flow and the gradient on slope stability. A model for the topographic influence on shallow landslide initiation developed by Mongomerry et al (1994) is applied to 24 places with similar terrain and subsurface flow. The criterion of landslide prone areas developed by Korea Forestry Administration (1998) is likely to misinterpreted under the condition of heavy rainfall. Soil saturation can be predicted by this model. This relative soil saturation can be used to analyze the stability of each topographic point in the case of cohesionless soils with spatially constant thickness and saturated conductivity. The three different stages of steady state rainfall predicting to cause instability in each topographic points provide a good measure of shallow landsliding possibility.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.594-596
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• 2007

Using an oedometer cell instrumented to measure the evolution of electromagnetic properties, small strain stiffness, and temperature, we conducted consolidation tests on four types of sediments. The tested specimens include sediments with different gas hydrate saturation at four stages of loading. The test results show that the electromagnetic and mechanical properties of hydrate-bearing marine sediments are governed by the vertical effective stress, stress history, porosity, hydrate saturation, fabric, ionic concentration of the pore fluid, and temperature. The results also show that permittivity and electrical conductivity data can be combined to estimate hydrate volume fraction in laboratory sediments, methodology that might eventually be extended for estimation of hydrate concentrations in field settings.

• 산업기술연구
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• 제33권A호
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• pp.49-54
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• 2013

The U-healthcare is increasingly important as there is a growing tendency for elderly people to acquire chronic disease such as heart problems and high blood pressure. In this paper, we implemented an oximeter which can interact and communicate with the smart devices such as smartphones through which users can manage their measuring data. The designed pulse oximeter is capable of detecting hemoglobin saturation levels in the range of 70-100% and the heart beat rate(BPM) in the range of 30-240 BPM.

• 약학회지
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• 제41권5호
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• pp.638-646
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• 1997

The steroid 9${alpha}$-hydroxylase activity has been detected in cytosol fraction, $100,00{\times}g$ supernatant of cell free extract of Mycobacterium fortuitum. The activity was not linear with protein concentration in the assay suggesting 9${alpha}$-hydroxylase is a multicomponent enzyme. The 9${alpha}$-hydroxylase system was partially purified through fractional saturation of ammonium sulfate, strong anion exchange (Mono Q) column chromatography, gel filtration (Superose 12) column chromatography, and testosterone affinity gel chromatography. Ammonium sulfate 50~60% saturated fraction of the cytosol gave 9${alpha}$-hydroxylase activity. For further purification, the half-saturated ammonium sulfate fraction was applied to Mono Q, Superose 12, or affinity gel column. The purification factors of 9${alpha}$-hydroxylase containing fraction after Mono Q, Superose 12, and affinity gel chromatography was 13, 11, and 17 respectively.

• Journal of Nutrition and Health
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• 제3권3호
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• pp.141-147
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• 1970

Nutritional anemias are an important nutritional problem affecting large population groups in most developing countries. Many reports on investigations of nutritional anemias have been published and there is good evidence that prevalence of iron deficiency anemias in vulnerable groups is high in many areas of the world. However, there is a general lack of accurate data on its prevalence throughout the world. Methods used to measure different factors have been variable and often of poor quality. Furthermore recent comparison of values obtained in different laboratories have shown a much greater discrepancy in iron binding capacity measurements as compared with serum iron determinations. Since the major cause of these differences appears related to the technique employed, the efforts of the central laboratory will be directed initially to standardization of methodology. My laboratory has been joined interlaboratory comparison of WHO studies of iron standardization. The determination of serum iron, iron-binding capacity and transferrin saturation was done on healthy adults, 79 males and 20 females, who visited hospital for health certificate from January to July 1970. The serum iron was determined by the method of modification of Bothwell and Mallett and total iron blinding capacity by Ramsay method and Bothwell and Mallett method. The results of this study are as follows; 1) The serum iron concentration of seventy nine adult male by the method presented is $131.5{\pm}37.3{\mu}g/100ml\;(range\;52.5{\sim}225.0{\mu}g/100ml)$ and of twenty female adult is $108.5{\pm}40.2{\mu}g/100ml\;(range\;45.0{\sim}202.5{\mu}g/100ml)$. 2) The adult male level of serum iron-binding capacity is $330.9{\pm}48.9{\mu}g/100ml\;and\;adult\;female\;is\;291.2{\pm}55.2{\mu}g/100ml$. 3) The transferring saturation of healthy male is $35.6{\pm}12.8%\;(range\;15.1{\sim}18.0%)\;and\;of\;female\;as\;25.4{\pm}12.4%\;(range\;10.1{\sim}60.0)$.

• Nutritional Sciences
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• 제1권1호
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• pp.52-55
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• 1998

This study was performed to investigate the effect of dietary iron intake on the immune status of male college students. Twenty healthy male university students participated in the study. The mean age of the subjects was 22.6 years old, mean height was 173.3 cm and mean body weight was 68.4 kg. The mean daily iron intake of the subjects was 19.9 mg, 158.1% of the Korean recommended dietary allowances (RDA). The blood iron status and immune responses of the subjects were analyzed and compared between the high dietary iron group consuming more than 100% of the RDA of iron (Hi-Fe) and the low dietary iron group consuming less than 100% of the RDA of iron (Low-Fe). The serum iron concentration and percent saturation of transferrin were within the normal range in both groups. However, the Hi-fe group had higher serum iron and percent saturation of transferrin than the Low-fe group (p<0.05). When differential white blood cell counts were compared, the Low-Fe group had a lower percentage of neutrophils than the Hi-Fe group (p <0.1). The plasma IL-2 concentration, immunoglobulin levels and lymphocyte subsets were not affected significantly by the differences in iron intake as shown in this study. Serum iron had a positive correlation with monocyte percentage but had a negative correlation with IgM concentration. The results of this study suggest that slightly-low dietary iron intake without anemia has no effects on the cell-mediated and humoral immunities of healthy male university students. However, natural defenses, such as neutrophils and monocytes, seem to be more sensitively affected by changes in dietary iron intake.

• 한국광학회지
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• 제8권4호
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• pp.353-355
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• 1997

공초점 형광 현미경과 단일 광자 계수기로 구성되어 있는 단일 분자 검출장치를 사용하여, 색소 농도에 따른 광자 계수율의 변화를 관측하였다. 농도가 증가함에 따라 계수율이 포화하는 경향을 보였으며, 광검출기의 죽은 시간을 고려하여 측정 결과를 설명하였다. 계수율과 검출 부피, 광검출기의 양자효율, 입사 광량 사이의 관계를 나타내는 관계식을 제시하였다. 또한 신호대 잡음비에 대해서도 간략하게 논하였다.

• ETRI Journal
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• 제11권4호
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• pp.75-83
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• 1989

The diffusion mechanism of Si in GaAs was investigated using different diffusion sources based on the Si-Ga-As ternary phase equilibria. The Si profiles are measured with secondary ion mass spectrometry and differ significantly for sources taken from the different phase fields in the ternary phase diagram. Neutral As vacancy diffusion is proposed for acceptor Si diffusion anneals using a Ga - Si - GaAs source. Donor Si diffusion using As - rich sources and a Si -GaAs tie line source shows concentration dependent diffusion behavior. Concentration dependent diffusion coefficients of donor Si for As - rich source diffusion were found to be related to net ionized donor concentration and showed three regimes of different behavior: saturation regime, intermediate regime,and intrinsic regime. Ga vacancies are proposed to be responsible for donor Si diffusionin GaAs: $Si_Ga^+V_Ga^-$ (donor Si -acceptor Gavacancy) complex for the extrinsic regime and neutral $V_G$a, for the intrinsic regime.The Si - GaAs tie line source resulted in two branch profiles, intermediate between the As - rich and the Ga - rich source diffusion cases.

• 한국해양공학회지
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• 제11권4호
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• pp.23-30
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• 1997

The purpose of this paper is to investigate the water environmental effect on the mechanical properties of carbon fiber/epoxy composites. Moisture concentration absorbed in CFRP under various water environment was calculated and degradation of mechanical properties for each wet composite laminates is investigated by performing the flexual and tensile test. The results show that moisture absorption is accelerated in higher temperature environment and under the same temperature sea water environment prompts more absorption than fresh water. As increasing the water temperature and moisture concentration tensile and flexual strength decreased as much as 25%-40% compared with dry condition.