• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.679-686
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• 2010

To investigate the contribution of macroalgae to biogeochemical nutrients and carbon cycles, we measured the uptake rates of nutrients and $CO_2$ by Undaria pinnatifida using an incubation method in an acrylic chamber. From January to March 2010, U. pinnatifida was sampled at Ilkwang, a well-known area of macroalgae culture in Korea. The initial and final concentrations of nutrients, dissolved oxygen, total alkalinity, and pH of the chamber water were measured, and production/uptake rates were calculated using concentration changes, chamber volume, and incubation time. The production rate of dissolved oxygen by U. pinnatifida (n = 32) was about $5.4{\pm}4.0\;{\mu}mol\;g_{fw}^{-1\;}h^{-1}$. The uptake rate of total dissolved inorganic carbon (TDIC), calculated by total alkalinity and pH, was $7.9{\pm}6.5\;{\mu}mol\;g_{fw}^{-1}\;h^{-1}$. Nutrients uptake averaged $141.7{\pm}119.2$ nmol N $g_{fw}^{-1}\;h^{-1}$ and $15.0{\pm}9.1$ nmol P $g_{fw}^{-1}\;h^{-1}$. A positive linear correlation ($r^2$ = 9.6) existed between the production rate of dissolved oxygen and the uptake rate of total dissolved inorganic carbon, suggesting that these two factors serve as good indicators of U. pinnatifida photosynthesis. The relationships between fresh weight and uptake rates of nutrients and $CO_2$ suggested that younger specimens (<~50 g fresh weight) are much more efficient at nutrients and $CO_2$ uptake than are specimens >50 g. The amount of carbon uptake by the total biomass of U. pinnatifida in Korea during the year of 2008 was about 0.001-0.002% of global ocean carbon uptake. Thus, more research should be focused on macroalgae-based biogeochemical cycles to evaluate the roles and contributions of macroalgae to the global carbon cycle.

• Archives of Pharmacal Research
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• v.19 no.2
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• pp.132-136
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• 1996

Exogenously applied oxygen free radical generating agent, pyrogallol, highly elevated extracellular glutamate accumulation and augmented N-methyl-D-aspartate (NMDA)-induced glutamate accumulation in cerebellar granule neuronal cells, but did not in astrocytes. Superoxide dismutase remarkably decreased the pyrogallol-induced glutamate accumulation, but either NMDA or kainate antagonists did not. In addition, pyrogallol did not affect the NMDAinduced intracellular calcium elevation. Pyrogallol partially blocked glutamate uptake into astrocytes. These results suggest that oxygen free radicals elevate extracellular glutamate accumulation by stimulating the release of glutamate as well as blocking the glutamate uptake.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.111-117
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• 1997

This study was carried out determine the effect of renal ischemia on amino acid transport in rabbit renal cortical slices. The animal models of renal ischemia induced experimentally by clamping the renal artery. These results were summarized as follows: 1. The uptake of amino acids lysine and ${\alpha}$-aminobutyrate(AIB), dicarboxylate succinate and organic anion PAH in cortical slices was normal or increased after 30 or 60 min of ischemia in vivo. 2. In a 30 min ischemic kidney, the slice uptake of amino acids was returned to the control level by 30 min of reflow. In a 60 or 90 min ischemic kidney, the lysine uptake was returned to the control level after of reflow, but the uptake of AIB and succinate was significantly reduced during reflow period of 30-120 min. 3. Oxygen consumption in cortical slices was increased after 30 min of ischemia but was not altered by 60 min of ischemia. This results indicat that transient ischemia caused increasing of amino acid uptake in renal cortical slices without metabolic disorder of renal proximal tubule.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.58.1-58.1
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• 2007

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• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.581-586
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• 2014

Main objects for wastewater treatment operation are to maintain effluent water quality and minimize operation cost. However, the optimal operation is difficult because of the change of influent flow rate and concentrations, the nonlinear dynamics of microbiology growth rate and other environmental factors. Therefore, many wastewater treatment plants are operated for much more redundant oxygen or chemical dosing than the necessary. In this study, the optimal control scheme for dissolved oxygen (DO) is suggested to prevent over-aeration and the reduction of the electric cost in plant operation while maintaining the dissolved oxygen (DO) concentration for the metabolism of microorganisms in oxic reactor. The oxygen uptake rate (OUR) is real-time measured for the identification of influent characterization and the identification of microorganisms' oxygen requirement in oxic reactor. Optimal DO set-point needed for the micro-organism is suggested based on real-time measurement of oxygen uptake of micro-organism and the control of air blower. Therefore, both stable effluent quality and minimization of electric cost are satisfied with a suggested optimal set-point decision system by providing the necessary oxygen supply requirement to the micro-organisms coping with the variations of influent loading.

• Journal of Oriental Neuropsychiatry
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• v.7 no.1
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• pp.39-48
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• 1996

This study was performed to investigate the effects of Qigong training after physical training stress in untrained college students For this study, 6 voluntary subjects(male 4, female 2) were chosen in untrained students of K University. they were trained by teachers during 6 weeks and tested just before Qingong training and after 6 weeks. Each subject was performed a treadmill exercise(model Q65, Quinton Co, U.S.A.) to the all-out state. During exercise stress test, electrocardiogram, heart rate were checked by stress test monitor(model Q4500, Quinton Co, U.S.A) and also oxygen uptake, maximal oxygen uptake analyzed continuously by automatic gas analysis(model QMC, Quinton Co, U.S.A). During physical training the serum were collected 3 times, pre-experimental rest time, and serum catecholamine were measured by HPLC.T-test of statistical analysis system was used in every experiment for statistical assessment. The results of T-test on these data were summarized as follow:1.Heart rate change during exercise stress test after Qigong training was shown more decreasing tendency than before training. Especially, heart rate change after Qigong training during resting periods was decreased significantly than before training.2. Oxygen uptake change during exercise stress test after Qigong training was shown more increasing tendency than before training, And also maximal oxygen uptake after Qigong training was shown more increasing tendency than before 6 weeks.3. Epinephrine level of after Qigong training was more decreased significantly than before training in all-out state. And norepinephrine level of after Qigong training was shown more decreasing tendency than before training in all-out state and after 30 minutes rest time. Above results indicate that Qigong training for 6 weeks could be effective to elevate the cardiopulmonary functions and diminish the stress responses of the physical stress.

• The Korean Journal of Physiology
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• v.3 no.2
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• pp.1-7
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• 1969

Physiological analysis of swimming in 13 (age:16.3 years, freestyle swimming) and 15 (age:17.2 years, breast stroke swimming) high school boys through oxygen uptake and oxygen debt measurements were performed. The following results were obtained. 1. In freestyle swimming oxygen debt was greater and mechanical efficiency was lower in subjects with less speed. In beginner efficiency was only 1.35%, whereas, in a more skilled subject it ranged to 4.28%. The mean efficiency was 2.59%. 2. In freestyle swimming the speed-oxygen debt curve was convex to the speed axis and the curve shifted to the right the more the speed was greater. 3. Maximal oxygen uptake in breast stroke swimming was 2.51 l/min or 41.8 ml/kin/kg and was 79.3% of treadmill running. Maximal pulmonary ventilation in breast stroke swimming was 73.1 l/min and was 87% of treadmill running. Maximal ventilation equivalent was 2.89 liters. 4. In subjects with greater speed of breast stroke swimming maximal oxygen uptake and mechanical efficiency of swimming were greater. The mechanical efficiency of breast stroke swimming averaged 1.08% $(range:0.51{\sim}1.70%)$. The coefficient of correlation between speed and efficiency was r=.87.

• The Korean Journal of Physiology
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• v.25 no.2
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• pp.171-177
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• 1991

This study was carried out to determine effect of acute renal ischemia on transport function of organic cation, tetraethylammonium (TEA), in rabbit kidney proximal tubule. Clamping of the renal artery for 30 and 60 min produced a polyuria which was accompanied by an increase in $Na^+$ excretion. The capacity of kidney cortical slices to accumulate TEA was increased after 30 and 60 min of ischemia. When blood flow was restored for 30 min after 30 and 60 min of ischemia, the augmented TEA uptake was recovered to the control values. Oxygen consumption of cortical slices was stimulated after 30 min of ischemia, whereas it was not altered by 60 min of ischemia. A 90-min ischemia produced a significant inhibition of TEA uptake and tissue oxygen consumption. These results suggest that the basolateral transport system for organic cation persists after ischemic periods of 60 min despite evidence that tubular reabsorptive mechanism of $Na^+$ and water is markedly impaired. This may indicate that the active secretory systems of proximal tubule are more resistant to ischemic injury than the reabsorptive systems.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.2
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• pp.74-79
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• 2010

The synthesis and reactivities of molybdenum carbide crystallites were examined in this study. Especially, the effect of synthesis conditions were scrutinized on the preparation of molybdenum carbide crystallites. In order to perform this purpose, various characterization techniques such as BET surface area and oxygen uptake measurements were employed for the synthesized molybdenum carbide crystallites. First of all, the molybdenum carbide crystallites were synthesized using molybdenum oxide crystallites and methane gas or methane-hydrogen mixture. The experimental results showed that BET surface areas ranged from $7.4m^2/g$ to $31m^2/g$ and oxygen uptake values varied from $8.1{\mu}mol/g$ to $24.3{\mu}mol/g$. The Mo compounds were found to be active for ammonia decomposition reaction. Even though there are some molybdenum carbide crystallites that were exceeded by Pt/$Al_2O_3$ crystallite, the steady state reactivities for other molybdenum carbide crystallites were comparable to or even higher than that determined for the Pt/$Al_2O_3$ crystallite. These results implied that molybdenum carbide crystallites could be one of the promising crystallites that might be substitutes for Pt-like noble metal crystallites in the petroleum processes.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.1
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• pp.47-54
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• 2014

Nanotechnology has become one of the fastest developing technologies and recently applied to a variety of industries. Thus, increasing number of nano materials including various nanoparticles would be discharged into wastewater and consequently entering a biological wastewater treatment process. However, the impact of the nano particles on biological wastewater treatment has not been estimated intensively. In this research, we investigated the effect of silica nanoparticle on the oxygen uptake rates (OURs) of activated sludge used in a conventional wastewater treatment process. The inhibition (%) values were estimated from the results of OURs experiments for the silica nanoparticles with various sizes of 10-15, 45-50, and 70-100 nm and concentrations of 50, 250, and 500 ppm. As results, the inhibition value was increased as the size of silica nano particles decreased and the injected concentration increased. The maximum inhibition value was investigated as 37.4 % for the silica nanoparticles with the size of 45-50 nm and concentration of 50 ppm. Additionally, the effect of size and concentration on the inhibition should be considered cautiously in case that the aggregation of particles occurred seriously so that the size of individual particles was increased in aquatic solution.