• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.380-391
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• 1993

The experimental study was made to propose the treatment method of wastewater in the high-density fish culture system. The BOD to COD ratios of effluents were almost same to 0.65 in the eel-farm, but were various in the farm rearing together with tilapia etc. A BOD rate curve of the eel-farm effluent could be described mathematically by the equation, $BODu=14.1(1-10^{-0.222t})+30.9(1-10^{-0.035(t-8)})$. Nitrification in Biological Fluidized Bed(BFB) system to treat the fish-farm wastewater could be reduce ammonium level up to $65{\sim}79\%$ when ammonium loading rates were between 0.014 and 0.075g $NH_4/g$ BVS-day. Nitrification efficiency was decreased by organic matters in the wastewater when ammonium loading was low(0.014 g $NH_4/g$ BVS-day). T-N removal ratios were decreased to increase loading in denitrification process, because of low C/N ratio. Based on much higher biological mass concentrations, BFB system takes many advantages of a practical viewpoint, such as stability of treatment efficiency and reduction of necessary site area for the facility, as compared with conventional treatment systems.

• Tuberculosis and Respiratory Diseases
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• v.39 no.6
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• pp.511-516
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• 1992

Background: It is well known that cigarette smoking is the risk factor of lung cancer, chronic obstructive pulmonary disease and ischemic heart disease. But there are few reports about the immediate effect of cigarette smoking on the cardiopulmonary functions. The serum level of carbon monoxide increases during cigarette smoking. It is known that carbon monoxide increases respration rate, heart rate and cardiac output, with decrease in maximal oxygen consumption. So we have studied to determine the immediate effects of cigarette smoking on the cardiopulmonary function during exercise. Method: Thirteen healthy smoking male subjects were included in this study. Each subject was undertaken pulmonary function test and incremental exercise test on two separate days, one without smoking (control) and the other after smoking three cigarettes per hour for five hours. The order of the two tests was randomized. Results: 1) The mean age of the subjects was $25{\pm}4.9$ year-old and the mean smoking history was $6{\pm}5$ pack years. 2) The mean blood level of carbon monoxide on the smoking day was higher than that on the nonsmoking day ($5.97{\pm}1.34%$ vs. $1.45{\pm}0.83%$; p<0.01). 3) The mean maximal oxygen consumption on the smoking day was lower than that on the nonsmoking day ($2.09{\pm}0.32$ L/min vs. $2.39{\pm}0.32$ L/min; p<0.05). 4) The mean anaerobic threshold on the smoking day was lower than that on the nonsmoking day ($1.33{\pm}0.24$ L/min vs. $1.53{\pm}0.20$ L/min; p<0.05). 5) The mean heart rate at rest on the smoking day was higher than that on nonsmoking day ($84.38{\pm}11.06$ beats/min vs. $75.46{\pm}5.83$ beats/min; p<0.05). But the means of maximal heart rate on both days were not different. 6) The pulmonary function tests were similar on both days. Conclusion: There was no change in pulmonary function test, but the maximal oxygen consumption and anaerobic threshold were decreased on the smoking day. So it was concluded that cigarette smoking impaired the cardiovascular functions immediately during exercise.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.942-953
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• 2019

The objective of this study was to evaluate the effects of L-arginine supplementation on muscle damage and fatigue indices and athletic performance improvement of canoe athletes after conducting a high-intensity training program. To achieve the objective, this study applied a high-intensity training program to seven high school canoe athletes. The high-intensity training program is composed of aerobic exercise sessions (twice per week; Tuesday and Thursday), anaerobic exercise sessions (three times per week; Monday, Wednesday, and Friday), and flexibility exercise sessions (five times per week). During the 6 week high-intensity training program, drug ingestion (L-arginine or placebo) was conducted in the first two weeks, wash out (two weeks) followed it, and drug ingestion (L-arginine or placebo) was carried out again in the last two weeks. The crossover design was used for the experiment so all study subjects were assigned to either the L-arginine intake group (the treatment group) or the placebo group (the control group). Each subject ingested 3g per day. This study confirmed the significant effects of L-arginine supplementation on muscle damage indices, fatigue indices, and antioxidants using blood samples. Additionally, FMD was analyzed to evaluate vascular endothelial cell functions and canoe performance was examined using the canoe ergometer. The results of this study showed that L-arginine intake did not have direct effects on the levels of ammonia, IP, and CK. The level of LDH decreased significantly more in the ARG group than in the PLA group due to L-arginine supplementation. Moreover, L-arginine supplementation did not change total NO, d-ROMs, BAP, and FMD significantly. Lastly, the results of the 500m canoe ergometer, which was conducted to evaluate the canoe performance, revealed that L-arginine did not have direct effects on total time, stroke distance, and mean velocity. However, L-arginine supplementation significantly improved muscle damage indices, fatigue indices, antioxidants, FMD, and canoe performance. Therefore, it is believed that additional studies are needed for examining the potential effects of L-arginine supplementation athletic performance enhancement.

• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.707-716
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• 2005

Organic geochemical analyses including Rock-Eval pyrolysis, elemental analysis and stable carbon isotope analysis were performed to evaluate the characteristics of organic matter in the ODP Leg 127 Site 794A sediments and to understand paleoceanographic changes. Based on the TOC contents, C/N ratio, HI vs. OI, $\delta^{13}C_{org}$ and C/S ratio, results imply that dark layers containing a large amount of terrigenous organic matter were deposited under the suboxic/anoxic conditions, whereas the light layers containing largely marine organic matter were deposited under the oxic conditions. These results indicate that increasing surface-productivity by the input of a large amount of terrigenous organic matter from adjacent continent led to the deposition of dark layers during the interglacial highstands, whereas marine primary production and dilution caused by Kosa from the China desert area led to the deposition of light layers with the decreased to terrigenous organic matter during the glacial lowstands.

• Journal of Industrial Convergence
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• v.19 no.4
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• pp.111-126
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• 2021

The purpose of this study was to investigate the effects of 12-week training on changes in physical fitness and cardiovascular factors for firefighters. For this purpose, 40 men in their 20s and 30s who agreed to participate voluntarily were recruited. They were divided into four groups: the firefighters' physical fitness test training group (hereinafter referred to as PT group), firefighters' physical fitness test and aerobic training group (hereinafter referred to as PT+AR group), firefighters' physical fitness test and both aerobic and anaerobic training group (hereinafter referred to as PT+CO group). Physical fitness factors (grip strength, back muscle strength, seated forward bend, standing long jump, sit-ups, 20-meter shuttle run), cardiovascular factors (total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, glucose, waist circumference, systolic blood pressure, diastolic blood pressure) and the relationship between Framingham Heart Risk Score and physical/cardiovascular factors were compared and analyzed, and the following conclusions were obtained. Aerobic training, anaerobic training, and combined training, including 12 weeks of firefighter physical examinations, all had positive effects on fitness and cardiovascular factors, which would be an appropriate way for firefighter examinees to improve physical strength and reduce the risk of cardiovascular disease.

• Tuberculosis and Respiratory Diseases
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• v.44 no.1
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• pp.154-161
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• 1997

Background : Although the long term adverse effects of cigarette smoking on health are well known, the acute possible detrimental effects of smoking on pulmonary or cardiovascular function, especially when these systems are stressed by the metabolic demands of exercise, have not been well studied The purpose of this study is to determine the acute action of cigarette smoking on cardiopulmonary function under stress. Method : Twenty -one healthy smoking subjects were studied. Before exrecise testing, history taking, physical examination and baseline studies, including CBC, chest PA, PFT and EKG, were done. The subjects performed an incremental bicycle exercise test to exhaustion on two occasions, one without smoking and the other after smoking 5 cigarettes/h for 2 hours. All indices of P.F.T. and bicycle ergometry were compared between before and after smoking. Results : 1. $VO_2$max and $O_2$ pulse showed significant decrease in smoking day. 2. Although there were no significant differences, anaerobic threshold showed a tendency of decrease and HRmax showed that of increase in smoking day. 3. P.F.T. and respiratory indices showed no significant change io smoking day. Conclusion : Cigarette smoking has immediate adverse effect, especially on the cardiovascular system rather than the respiratory system. These results would be due to the effect of elevated HbCO and/or impaired blood flow in response to the exercise stimulus.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.92-100
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• 1997

Distribution of bacterial abundance and production was investigated during October, 1995-August, 1996 in Lake Shiwha constructed artificially in 1994. Its water column was distinguished by two layers: the brackish surface layer with salinity ranged from 6 to 20‰ and the saline hypoxic/anoxic bottom layer with salinity of 17 to 27‰ Except for samples collected in March, 1996 (on average 13 ${\mu}g\;l^{-1}$), chlorophyll a concentration ranged from 27.6 to 249.5 ${\mu}g\;l^{-1}$ in the euphotic zone, indicating the hypertrophic condition of Lake Shiwha during most of the studied period. In this study, bacterial productions measured by $^3H$-thymidine incorporation method were similar to those by $^{14}C$-leucine incorporation method. In hypertrophic, surface waters of Lake Shiwha, bacterial abundance and production ranged from 1.4 to $19.5{\times}10^9\;cells\;l^{-1}$ and from 1.6 to $126.5{\times}10^7\;cells\;l^{-1}\;h^{-1}$ respectively; 2 to 4 fold and 2 to 30 fold higher than those in eutrophic coastal waters outside of Lake Shiwha, respectively. Turnover times of bacterial community in the surface layer of Lake Shiwha ranged from 0.2 to 8.9 day, indicating that bacteria in the lake seemed to adapt to the hypertrophic condition. In the hypoxic bottom layer, bacterial abundance and production was up to 3 fold and 20 fold lower than those in the surface layer, and showed slow bacterial growth. Significant correlations between the bacterial abundance, production, and community turnover time with water temperature indicate water temperature was the important factor controlling distribution and growth of bacteria. However, during summer season, bacterial production seemed to be regulated by supply of substrates.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.53-68
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• 1997

Lake Shihwa, artificially constructed since 1988, shows a typical two-layered system depending on strong haline density stratification. Sill of the water gate at 6 m depth greatly restricts physical mixing with outer seawater and circulation in the lake, and contributes to the enhancement of anoxic environment in the deeper layer. With this enclosed physical environment, Lake Shihwa receives enormous amounts of organics, ammonia, and other pollutants from the neighboring municipal and industrial complexes through six major streams, thus developing biogeochemical differentiation of anoxic to suboxic environment in the high saline bottom water and highly eutrophicated brackish surface water. This study investigated vertical structures, biogeochemical behaviors and processes of various organic and inorganic compounds around oxic-anoxic interface. Nitrite and nitrate rapidly decreased below the pycnocline where about $1{\times}10^8$ tons of hypoxic bottom water exist. In this bottom layer, ammonium ranged from 75 to 360 ${\mu}M$ mainly resulting from deamination of dissolved organic nitrogen and ammonification of precipitated organic particles. Despite large amounts of surface water discharge and dilution by outer seawater inflow about $3{\times}10^8$ tons from April to August, 1996, bottom layer did not show any improvement of water quality and maintained highly reduced environment. The main reason seems to be imbalance between ineffectiveness of dilution due to shallow depth and large surface area, overloaded POC influx from the eutrophicated surface biological activity, and poor replenishment of oxygen in this artificial lake system. Therefore, as long as current salinity dependent two-layered system maintains with its physical limitations, any improvement of water quality cannot be foreseen in Lake Shihwa.

• Parasites, Hosts and Diseases
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• v.27 no.3
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• pp.187-196
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• 1989

The effects of gamma irradiation on the survival and development of C. sinensis metacercariae were studied to evaluate the feasibility of irradiation as a control measure for clonorchiasis. Pseudorasbora parve were collected at an endemic river of clonorchiasis and were used for irradiation of the fluke in three schemes. The first (Scheme 1) was irradiation of the isolated metacercariae from the fish followed by infection to experimental rats. The second (Scheme 2) was irradiation of the fish, and then the metacercariae were isolated and in(ected to rats. The third (Scheme 3) was irradiation on the rat livers after infection with normal metacercariae. Irradiation doses varied from 5 to 100 Gy for Schemes 1 and 2, and 10 to 25 Gy for Scheme 3. The rats were sacrificed 2 to 6 weeks after infection. In Scheme 1, the metacercariae irradiated at 50 Gy failed to survive in the rats after 2 or 6 weeks. However, 1 to 44% of the metacercariae irradiated at 5∼30 Gy survived. The estimated LD50 of Scheme 1 was 16.5 Gy. The flukes irradiated in Scheme 2 survived better than those in Scheme 1. The average worm recovery rate in 50 Gy was 28%(7∼39% individually). Increasing the dose up to 100 Gy brought a remarkably low survival rate of an average 1%(0∼3% individually). The LD50 of Scheme 2 was 47.5 Gy. Worm recovery rates in the 10 Gy group of Scheme 3 were 21∼39%, and those in the 25 Gy group were 2% and 34%. Although the metacercariae were irradiated, all of the recovered worms were morphologically normal. Only the worms irradiated with 10 Gy or 25 Gy after 9 days from infection in Scheme 3 showed underdeveloped testes and seminal receptacle. The present results suggest that irradiation of the fish by 100 Gy could be adopted as a control measure for clonorchiasis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.392-400
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• 1993

The present study was accomplished to understand the occurrence and time serial variations of oxygen-deficient watermass in wonmun Bay from 1989 to 1991. From the results of this work, oxygen-deficient water was periodically observed in bottom layer and in Summer in this region. The stratification of water began to develop in Spring and the strong formation of oxygen-deficient water showed in Summer but it gradually disappeared in Autumn. It seems that the occurring and continuing period of very low dissolved oxygen watermass is intensively controlled by meteorological conditions and vortical stratification of water column. On formation of oxygen-deficient watermass, high nutrient concentrations in the bottom layer appear to be due to release of nutrients from bottom sediment. The dissolved inorganic phosphate versus AOU shows two linear curves according to the level of AOU. In the relationships between phosphate and AOU, the gradient of a linear curve over approximately 5mg-AOU/l was significantly large, presumably indicating dissolution of phosphate from the sediment.