• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.896-901
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• 2012

In this research, the levels of concentrations from the junction of effluent from wastewater treatment plant during dry days and combined with runoff from the surrounding 11 ha livestock catchment area during wet days were determined to investigate the relationships of the concentration of various pollutants such as particulates, nutrients and organics originating from point and nonpoint sources. Manual sampling was conducted from October 2008 to December 2011 during dry and wet days. Based on the results, the flow rates and concentrations of most pollutant parameters were increased during wet days. It was found out that the effluent wastewater combined with stormwater runoff has low BOD to TN/TP ratio and high TN/TP to BOD ratio. Therefore, it is needed to employ other treatment methods to effectively manage the wastewater and reduce the pollutant discharge to receiving water bodies.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.6
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• pp.613-619
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• 2016

A pneumatic control valve performs a major role in controlling the flow of a system or the level of a key tank in many power plants, and its performance should be guaranteed during the plant's lifetime. Its operation starts by supplying air to the pneumatic actuator or by exhausting the air from the actuator. To control the valve position, the amount of air supply or exhaust is adjusted by a control loop where various accessaries are equipped. In this paper, air leakage in the air supply line, changes in the valve packing force, and false adjustments of zero and the span of the positioner are simulated and analyzed using a 2-in pneumatic valve with a position control loop including an I/P converter and positioner, where the valve position is controlled within ${\pm}2%$ of the control pressure at 67% opening position.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.687-699
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• 2013

This study was conducted to examine the effect of grafted peppers (Capsicum annuum) on different rootstocks on fruit quality. Three pepper cultivars, 'Nokkwang', 'Saengsaeng Matkkwari', and 'Shinhong' were grafted onto five commercial rootstocks that are known to be resistant to Phytophtora blight. Non-grafted or auto-grafted peppers were used as controls. Grafted plants were grown during two consecutive harvest periods by semi-forcing culture (April to August) and retarding culture (September to March the subsequent year). Full size green fruits were harvested and weighed weekly from June to August (Semi-forcing culture) and from December to March of the subsequent year (Retarding culture). The fruit size, weight, flesh thickness, and firmness were measured every month. Total marketable yield was not significantly influenced by either auto-graft of 'Nokkwang', 'Saengsaeng Matkkwari', and 'Shinhong' of pepper or grafted with the five commercial rootsctocks. By contrast, grafting influenced the apparent fruit quality of peppers. Fruit characteristics differed depending on the rootstock cultivars. However, the fruit characteristics of rootstock did not affect the fruit characteristics of scion grafted onto that rootstock. Fruit characteristics in each treatment differed among harvest time (first, second, and third harvest). Fruit quality parameters were also different as affected by the harvest period. In conclusion, apparent quality and textural property of pepper fruits were influenced by not only grafting with different rootstocks but also by the harvest period and harvest time. Accordingly, rootstock/scion combination, the scion variety and the harvest period must be carefully chosen to get the desired optimal fruit quality.

• Korean Journal of Pharmacognosy
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• v.47 no.1
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• pp.49-54
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• 2016

In our search for natural products affecting blood circulation, the n-butanol fraction from whole plant of Glehnia littoralis Fr. Schm. (GLB) improved blood lipid parameters, and ameliorated obesity in high-fat-diet (HFD)-fed C57BL/6 mouse model. Hyperlipidemia was induced by high-fat-diet for 4 weeks, and then GLB was orally administrated with 400 mg/kg/day for 4 weeks. GLB-treated group showed that the gain in body weight was significantly attenuated, the levels of total cholesterol and triglyceride significantly lowered on blood chemical analysis, and significantly prolonged the mice bleeding time when compared with those of HFD control group. Concomitantly, phytochemical composition of GLB was investigated by HPLC-hyphenated spectroscopy, and two major phenolic compounds, rutin and chlorogenic acid were identified in the GLB. Taken together, these results indicate that GLB has cardiovascular protective effects and could be a natural medicine candidate for the prevention of cardiovascular disease.

• Korean Journal of Medicinal Crop Science
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• v.22 no.1
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• pp.38-45
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• 2014

This study was performed to investigate the physiological responses of Oplopanax elatus by water condition. Drought stress was induced by withholding water for 26 days. The results show that $P_{N\;max}$, SPAD, gs, E and Ci were significantly decreased with decreasing of soil moisture contents. However, AQY and WUE were decreased slightly only at 26 day. This implies that photosynthetic rate is reduced due to an inability to regulate water and $CO_2$ exchange through the stomatal. According to JIP analysis, ${\Phi}_{PO}$, ${\Psi}_O$, ${\Phi}_{EO}$ and $PI_{ABS}$ were dramatically decreased at 21 day and 26 day, which reflects the relative reduction state of the photosystem II. On the other hand, the relative activities per reaction center such as ABS/RC, TRo/RC were significantly increased at 26 day. Particularly, Dio/RC and DIo/CS increased substantially under drought stress, indicating that excessive energy was consumed by heat dissipation. These results of chlorophyll a fluorescence show that the sensitivity changes photosystem II activity. Thus, according to the results, O. elatus was exhibited a strong reduction of photosynthetic activity to approximately 10% soil moisture contents, and JIP parameters could be useful indicator to monitor the physiological states of O. elatus under drought stress.

• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.223-226
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• 2008

Seedlings of two rice cultivars i.e. cv. Daesanbyeo and cv. Dongjinbyeo were analyzed for growth and endogenous gibberellins (GAs) in response to nitrogen nutrition applied in the forms of $KNO_3$, $(NH_4)_2SO_4$ and $NH_4NO_3$. All the growth parameters showed an increase in N applied treatments and their magnitudes of increase were different depending on different nitrogen fertilizer forms. The endogenous GAs contents were increased with N application but differentially affected by various N-forms in both rice cultivars. In cv. Daesanbyeo, maximum amount of bioactive $GA_1$ was recorded for $(NH_4)_2SO_4$, while maximum amount of bioactive $GA_1$ in cv. Dongjinbyeo was observed in $NH_4NO_3$ applied treatments. In both rice cultivars, $KNO_3$ applied rice plants contained least $GA_1$ contents. Also, $GA_{19}$ was the most abundant GA found in rice seedlings whereas $GA_4$ was absent at seedling stage. Our study indicated that different rice cultivars showed different responses for the same fertilizer depending upon the response potential of each cultivar and the pertinent physiological responses to changes of endogenous GAs in rice cultivars, which were comparatively lesser in magnitude.

• Korean Journal of Ecology and Environment
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• v.42 no.4
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• pp.422-431
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• 2009

This study was to provide basic data for aquatic ecosystem research using fishes. Field sampling was carried out at five selected sites of Gap Stream, and fish samples, especially for a selection of sentinel species were collected three times in June, September, and October 2007. We analyzed total length distribution of Zacco platypus in relation with the season and the sampling sites, and then compared with total body weight, condition factor (K), and age distribution of the fish. The fish population data were compared with physico-chemical water quality, obtained from the Ministry of Environment, Korea. Water quality analysis showed a significant nutrient enrichment, based on total nitrogen (TN) and total phosphorus (TP), and organic matter pollution, based on biological oxygen demand (BOD) and chemical oxygen demand (COD) in the Site 5, which is directly influenced by wastewater disposal plant (WDP). Population analysis of the sentinel species showed that the total number of individuals, age distribution, and the population size-structure were influenced by the effluents from the WDP, and that reproductive failure of young-age population were evident in Site 5. According to the relation analysis of total weight to K, the disturbed population was mainly attributed to combined effects of habitat modifications and chemical degradations. Regression analysis of K values against water quality parameters showed significant (p<0.05) positive relations with nutrient and organic matter contents. Our data suggest that the population structure using a sentinel fish species reflected the ambient water quality in the stream and that diagnosis of aquatic ecosystem health using Z. platypus population may be practical for water resource and ecosystem conservations.

• Journal of Life Science
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• v.27 no.5
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• pp.579-583
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• 2017

Tetragonia tetragonioides seems to be a promising antiulcer medicinal plant due to the presence of water-soluble polysaccharide and cerebroside as its major constituents. There have been no previous studies using T. tetragonioides polysaccharide extract (TPE) to assess its antidiabetic effect in streptozotocin (STZ)-induced diabetes in mice. This study was designed to evaluate the antidiabetic effect of TPE in diabetic mice, which was established by one-week intraperitoneal injection of 65 mg/kg STZ. After three weeks of TPE treatment at a dose of 100 mg/kg, a maintenance of body weight, a decrement in plasma glucose, and low levels of triglyceride, lactate dehydrogenase, alkaline phosphatase, and glutamic pyruvic transaminase were observed in diabetic mice. Furthermore, the ingestion of TPE lowered the blood glucose levels during the oral glucose tolerance test (OGTT) and restored most of the tested parameters to their normal levels. Therefore, the antidiabetic potential of T. tetragonioides has been demonstrated for the first time by our research.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.244-249
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• 2012

This study was carried out to investigate effect of serum lipid and liver tissue in lectin from Viscum album on rats. The lectin was purified by sepharose 4B affinity chromatography and gel filtration using sephadex G-150 with plant material from Viscum album. After 72 h of $CCl_4$ injection, there was a significant increase in serum total cholesterol and triglycerige levels relative to the control group. However, treatment of both Viscum album and purified lectin were significantly decreased lipid parameters against the $CCl_4$-induced. Histological observation of the liver section of rats challenged with $CCl_4$ produced a marked increase of cytoplasmic vacuoles in number, while rats administered olive oil alone did not alter the normal hepatic architecture. Histological observation of the liver section in rats treated 72 h with either Viscum album purified lectin or $CCl_4$-induced liver lipogenesis showed decreased numbers of cytoplasmic vaculoes and necrotic cells. These results suggest that Viscum album lectin has a significantly decreased lipid in serum or histological observation of the liver section decreased in lipogenesis in rats.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.5
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• pp.355-361
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• 2000

A recycling reactor system operated under sequential anoxic and oxic conditions for the treatment of swine wastewater has been developed, in which piggery slurry is fermentatively and aerobically treated and then part of the effluent is recycled to the pigsty. This system significantly removes offensive smells (at both the pigsty and the treatment plant), BOD and others, and may be cost effective for small-scale farms. The most dominant heterotrophic were, in order, Alcaligenes faecalis, Brevundimonas diminuta and Streptococcus sp., while lactic acid bacteria were dominantly observed in the anoxic tank. We propose a novel monitoring system for a recycling piggery slurry treatment system through the use of neural networks. In this study, we tried to model the treatment process for each tank in the system (influent, fermentation, aeration, first sedimentation and fourth sedimentation tanks) based upon the population densities of the heterotrophic and lactic acid bacteria. Principal component analysis(PCA) was first applied to identify a relationship between input and output. The input would be microbial densities and the treatment parameters, such as population densities of heterotrophic and lactic acid bacteria, suspended solids(SS), COD, NH$_4$(sup)+-N, ortho-phosphorus (o-P), and total-phosphorus (T-P). then multi-layer neural networks were employed to model the treatment process for each tank. PCA filtration of the input data as microbial densities was found to facilitate the modeling procedure for the system monitoring even with a relatively lower number of imput. Neural network independently trained for each treatment tank and their subsequent combined data analysis allowed a successful prediction of the treatment system for at least two days.