• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.123.1-123
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• 1998

• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.327-336
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• 2001

Physical, chemical, and biological parameters were measured during the period from July 1993 to August 1994 near the Munui intake tower of Taechung Reservoir to evaluate effects of nutrients and suspended solids on algal chlorophyll-a and water clarity. Large amounts of precipitation during summer 1993 produced minimum conductivity ($88\;{\mu}S/cm$), minimum TN : TP (<40), and maximum total phosphorus (TP;$59\;{\mu}g/L$) and resulted in a chlorophyll-a peak ($79\;{\mu}g/L$) and minimum transparency (<1.5 m) among the seasons. At the same time, ratios of volatile suspended solids (VSS): non-volatile suspended solids (NVSS) were maximum (13.0),indicating that the reduced transparency was mainly attributed to biogenic turbidity in relation to phytoplankton growth. In contrast, severe drought in summer 1994 resulted in greater conductivity (>$120\;{\mu}S/cm$), water clarity (%gt;2 m), and lower TP and chlorophyll- a (<$10\;{\mu}g/L$) relative to those of summer 1993. Total phosphorus ($R^2=0.46$, n=59) accounted more variations of chlorophyll- a compared to total nitrogen ($R^2=0,29$, n=59). The mass ratios of TN : TP ranged from 39 to 222 and were strongly correlated with TP (r = -0.80) but not with concentrations of TN (r = 0.05). Ambient nutrient concentrations and TN : TP mass ratios indicated that seasonality of chlorophyll- a was likely determined by concentrations of phosphorus reflected by the distribution of rainfall. It was concluded that reductions of phosphorus during heavy rainfall may provide better water quality for the drinking water in the intake tower.

• Journal of Acupuncture Research
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• v.22 no.3
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• pp.137-144
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• 2005

Objective : This study was designed to assess the heart rate variablitv of patients with Parkinson's disease according to Hoehn-Yahr stage. Methods : Subjects were voluntarily recruited by newspapers and internet. All the subjects are confirmed as idiopathic parkinson's disease by a neurologist. The patients were grouped by Hoehn-Yahr(H-Y) stage. Heart rate variability was measured for 5 minutes after 5 minutes' bed rest. Subjects were comprised of 3 groups which were H-Y stage I (n=14), H-Y stage H(n=9), H-Y stage III(n=7). We compared the heart rate variability of each groups by one-way ANOVA test. We also studied the relationship between UPDRS score and Heat rate variability components (SDNN, RMS-SD and TP) by pearson correlation analysis and simple linear regressin analysis Results: Age, duration was matched among groups. SDNN, RMS-SD, TP were significantly decreased as H-Y stage increased(p<0.05). Especially there was significant difference between H-Y stage I and III group(p<0.05). But other components(Heart rate, LF, HF, LF/HF ratio) were not showed significant difference. SDNN, RMS-SD and TP were significantly decreased as UPDRS scores increase(p<0.05). Conclusion : This study suggests that the function of the autonomic nervous system decreases as Parkinson`s disease progresses.

• Journal of Korea Water Resources Association
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• v.54 no.9
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• pp.693-704
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• 2021

The purpose of this study is to evaluate the relationship between heat wave and river water quality. The daily maximum air temperature (Tmax) of 91 meteorological stations of the Korea Meteorological Administration and 13 river water quality factors (DO, BOD, COD, TOC, TN, DTN, NH4-N, NO2-N, NO3-N, TP, DTP, PO4-P, Chl-a) of Ministry of Environment were analyzed. The correlation analysis was performed on Tmax and water quality factors, and the determination coefficients (R²) of DO, Chl-a, and TN with Tmax showed high values of 0.782, 0.609, and 0.691 respectively. To analyze the spatial impact between heat waves and water quality factors, the heat wave intensity (HWI) and heat wave duration (HWD) were calculated using the Tmax. The hotspot and spatial statistical analyses were applied for spatial impact evaluation. As a result of hotspot analysis, the heat wave index (HWD, HWI) showed high spatial pattern in the downstream of Nakdong River basin, and Chl-a and TN showed the same pattern. In case of spatial statistical analysis for water quality due to heat wave, the most obvious spatial variability was DO.

• Environmental Engineering Research
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• v.16 no.2
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• pp.61-67
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• 2011

The water quality from nonpoint source run off results from different land use types has been studied. The construction of a buffer strip is one method of nonpoint source pollutant control. The Soil and Water Assessment Tool (SWAT) model has been applied to estimate the pollutant removal through the buffer strip. When the non-business land has been changed into grass to form a buffer-strip, the change of land use effects the results of the model according to measures of the water quality. The data from a water level station within the watershed in the years 2006 and 2007 was used for calibration and validation of the model. Under the rainfall conditions in 2007, the removal rates of SS, BOD, TN, TP were 11.5%, 9.5%, 1.2%, and 4.5%, respectively. During the rainy days, the removal rates at the buffer strip were 92.3% of SS, 91.2% of BOD, 82.4% of TN, and 83.5% of TP. The pollutants from nonpoint sources were effectively removed by over 80% as they passed through the buffer strips. Rainfall resulted in soil erosion, which led to an increase in the SS concentration, therefore, the construction of buffer strips protected the streams from SS inflows. Since TN concentrations are affected by the inflows of ground water and the N concentration of the rainfall, the removal rate of TN was relatively lower than for the other pollutants.

• KCID journal
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• v.21 no.1
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• pp.55-63
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• 2014

A sedimentation basin for agricultural water quality improvement was researched to analyze the water quality purification characteristics. The sedimentation basin constructed at the inlet of Gamdon reservoir in Muan-gun, Jeollanam-do was selected as the research field of this study. The surface area of the sedimentation basin is $34,000m^2$, volume is $122,000m^3$, and hydraulic retention time is 0.3hr~7.3day. The average influent loading of SS was 156.6kg-SS/d, and the effluent loading was 67.5kg-SS/d with the average removal rate of 56.9%. The average influent loadings of BOD and COD were 33.0kg-BOD/d and 60.3kg-COD/d respectively, and the effluent loadings were 26.4kg-BOD/d and 48.6kg-COD/d with the average removal rate of 20.1% and 19.3% respectively. Therefore, the results of this study show that a sedimentation basin can purify SS and organic matters. The average influent loadings of T-N and T-P were 28.7kg-TN/d and 2.97kg-TP/d respectively, and the effluent loadings were 16.3kg-TN/d and 1.41kg-TP/d with the average removal rate of 43.0% and 52.6% respectively. In conclusion, the overall results of this study show that a sedimentation basin is a feasible alternative to purify organic matters and nutrients.

• Journal of Electrical Engineering and information Science
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• v.3 no.3
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• pp.316-321
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• 1998

In recent years, concern has been raised about the technique of controlling electrical breakdown by using laser in many fields. Especially, laser has attracted much attention in the Electro-Discharge Macining(EDM) because of its many merits. Therefore, this research has been performed to obtain fundamental data relevant to discharge processing by using a pulsed Nd:YAG laser. The experiments of laser-guided dc discharge by laser radiation have been carried out at low air pressure ranging from 0.2 to 20 torr. The minimum laser-guided dc discharge voltage V\ulcorner at the given pressures P and distances D between an anode and a cathode was measured. It is found that the minimum laser-guided dc discharge voltage is much lower than the natural discharge voltage V\ulcorner\ulcorner, and the values of V\ulcorner and V\ulcorner as a function of P.D has a similar tendency. The laser output energy Eout decreases with input pulse duration tp increasing, and the more the value of tp increases, the higher that of V\ulcorner is obtained because the number of photons during the discharge time N decreases with t\ulcorner increasing. There is the time lag frequently when the discharge by laser radiation is misguided under the condition of the applied voltage less than V_G.min.

• Fisheries and Aquatic Sciences
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• v.6 no.3
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• pp.149-154
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• 2003

The characteristics of pollutant loads from the various sources and seawater quality in Kwangyang Bay were evaluated. Total flow rate was estimated to be $10,868,066.8 m^3/day$ with a flow rate of R2l (the Seomjin River) as the highest one. Total COD, TN and TP loads of the input rivers and the ditches were about 27,591.8, 25,029.6 and 586.4 kg/day, respectively. Wastewater discharging loads was the greatest contributors to pollutant loads in the inner part of Kwangyang Bay. COD values in the inner part of the bay was over 3.0 mg/L, which exceeded the seawater quality criteria III of Korea. The average values of DIN and DIP were 8.62 ${\mu}gN/L\;and\;1.26\;{\mu}gP/L$, respectively. The limiting factor for algal growth was DIN. In he total discharging loads of the watershed from unit loading estimations, BOD, TN and TP were 9,132.3, 2,727.2 and 304.2 kg/day, respectively. In addition, municipal sewage by the population as pollution sources and the city of Kwangyang as administrative district had the highest loads. For a appropriate water quality recovery of Kwangyang Bay, it is suggested that it is essential to estimate reduction rate of total pollutant loads by water quality modeling.

• Microbiology and Biotechnology Letters
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• v.21 no.1
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• pp.30-35
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• 1993

Clp is a relatively abundant ATP-dependent protease found in E. coli. Its specific activity was proportional to the concentration of the limiting amount of Clp A and an excess amount of Clp P, and vice versa. Clp A has an intrinsic ATPase activity that is stimulated by casein, and contains a second site for binding A TP, in addition to the ATPase site. The modification of sulfhydryl groups in Clp A with reagents which have bulky groups such as N-phenylmaleimide led to nullifying both ATPase and protease activity. The same sites were modified by sulfhydryl reagents. It seems that the sulfhydryl groups of Clp A are not directly involved in catalysis. Since non-hydrolyzable analogs of ATP do not activate Clp, ATP hydrolysis may be essential for the proteolytic activity of Clp protease. Clp A and Clp P did not associate in the absence of nucleotide. The results suggest that the activity of the proteolytic component, Clp P, is regulated by the A TP-dependent cycling of Clp A between the activator form and the non-activator form.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.1017-1021
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• 2011

Two new benzimidazolyl-containing complexes have been synthesized by reactions of $Cu^{II}$ salts and 1,2-bis(benzimidazolyl) benzene ($H_2bbbz$) with two different dicarboxylate ligands. When phthalate acid ($H_2pt$) was employed as secondary ligand, a 0D molecular complex Cu$(H_2bbbz)(pt){\cdot}(H_2pt)$ (1)was furnished and when the secondary ligand was instead by a linear bridging ligand of terephthalic acid ($H_2tp$) a 1D zipper-like coordination polymer $[Cu(H_2bbbz)(tp){\cdot}2(C_2H_5OH){\cdot}H_2O]_n$ (2) was obtained, suggesting the structure-direction effect of the secondary dicarbxylate ligand. The preliminary investigation on the spectral properties of the complexes was also presented.