• Journal of Bio-Environment Control
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• v.9 no.1
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• pp.11-19
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• 2000

In recent, multi-sector nutriculture in which each sectors are managed with different compositions and supplying amounts of nutrient solution is being prevalent especially in large-scale greenhouses. This study was carried out to develop an automatic mixing and supplying system of nutrient solution for the multi-sector greenhouse which can control various compositions of nutrient solution and supplying amounts for each sector. The stock solution control device could control discharge of the stock solution with device actuating time. The experimental result showed high correlation between the discharge and the actuating time. The system could make nutrient solution of various compositions and showed possibility of changing compositions of nutrient solution according to changes of growth stages or environments. Undesirable remnant nutrient-solution effect on the next supply was decreased by lowering RC of the previous nutrient solution remaining in the tank and supply pipe through rinse process. To evaluate performance of the developed system, experiments that compare N $O_3$$^{[-10]}$ , and P $O_4$$^{3-}$ concentrations of nutrient solution made in laboratory level with those made by the developed system were conducted. The experimental results showed that the deviations for N $O_3$$^{[-10]}$ , and P $O_4$$^{3-}$ concentrations of nutrient solution composited by the developed system were -2.36％ and -5.15％, respectively.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2007.05a
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• pp.261-265
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• 2007

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.505-515
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• 2015

The objectives of this study were to determine the effects of stream nutrient regime, N:P ratios and suspended solids on fish tolerance/trophic compositions and stream ecosystem health, based on multi-metric model, during 2008-2013. Also, stream ecosystem health was evaluated in relation to chlorophyll-a (CHL) as a measure of algal productivity or indicators of trophic state to water chemical parameters. Total number of sampled fish species were 50 and showed a decreasing trend from 2008 to 2013. The minnow of Zacco platypus, based on the catch per unit effort (CPUE), was the most dominant species (25.9%) among the all species. Spatial heterogeneity was evident in the fish tolerance guilds that showed the dominance of sensitive species (89%) in the headwaters (S1) and the dominance of tolerant species (57%) in the urban. These conditions were directly influenced by concentrations of nutrients and organic matter (COD). The N:P ratios, as a barometer of water pollution, had a negative linear function (R² = 0.40, P < 0.01) with CHL, and the ratios had an important role in changes of COD concentration (R² = 0.40, P < 0.01). Under the circumstances, the N:P ratio directly influenced the relative proportions of fish trophic/tolerance compositions. According to the regression analysis of omnivore (O_m) and insectivore sp. (I_n) on total nitrogen and total phosphorus, nitrogen had no significant influences (P > 0.05) to the two compositions, but phosphorus influenced directly the two guilds [slope (a) = -32.3, R² = 0.25, P < 0.01 in the I_n; a = 40.7, R² = 0.19, P < 0.01 in the O_m]. Such water chemistry and fish trophic guilds determined the stream ecosystem health, based on the multi-metric fish model.

• Nutrition Research and Practice
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• v.6 no.1
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• pp.21-27
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• 2012

Pumpkins have considerable variation in nutrient contents depending on the cultivation environment, species, or part. In this study, the general chemical compositions and some bioactive components, such as tocopherols, carotenoids, and ${\beta}$-sitosterol, were analyzed in three major species of pumpkin ($Cucurbitaceae$ $pepo$, $C.$ $moschata$, and $C.$ $maxima$) grown in Korea and also in three parts (peel, flesh, and seed) of each pumpkin species. $C.$ $maxima$ had significantly more carbohydrate, protein, fat, and fiber than $C.$ pepo or $C.$ $moschata$ (P<0.05). The moisture content as well as the amino acid and arginine contents in all parts of the pumpkin was highest in $C.$ $pepo$. The major fatty acids in the seeds were palmitic, stearic, oleic, and linoleic acids. $C.$ $pepo$ and $C.$ $moschata$ seeds had significantly more ${\gamma}$-tocopherol than $C.$ $maxima$, whose seeds had the highest ${\beta}$-carotene content. $C.$ $pepo$ seeds had significantly more ${\beta}$-sitosterol than the others. Nutrient compositions differed considerably among the pumpkin species and parts. These results will be useful in updating the nutrient compositions of pumpkin in the Korean food composition database. Additional analyses of various pumpkins grown in different years and in different areas of Korea are needed.

• International Journal of Industrial Entomology and Biomaterials
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• v.42 no.1
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• pp.14-20
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• 2021

Mulberry was dried with low temperature vacuum dryer using microwave. The nutritional compositions of microwave-dried mulberry including proximate composition, sugar content, mineral content, total phenolic, flavonoids, and anthocyanin, beta-carotene, vitamin C, and amino acid composition were measured. Sugar contents of mulberry were 42.6 mg/100g (Cheongilppong) and 43.27 mg/100g dw (Gwasang No. 2). The main components of mulberry sugars were fructose and glucose. Mineral analysis showed that K, P, Ca, and Mg were abundant regardless of mulberry cultivars.

• Journal of Bio-Environment Control
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• v.7 no.2
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• pp.123-129
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• 1998

This experiment was conducted to composition of nutrient solution for tore of endive hydroponics, and was compared the nutrient solution developed in the Seoul City University(SCUE) with the conventional solution of Proefstation voor Tuinbouw ender Glas. Proper compositions of nutrient solution for endive hydroponics were NO$_3$-N 15.0, NH$_4$-N 1.0, PO$_4$-P 3.0. K 10.0, Ca 5.0 and Mg 3.5 me.$\ell$$^{-1}$ , respectively SCUE and PTG standard nutrient solution showed slightly better yields among nutrient solutions. The SCUE nutrient solution and the PTG nutrient solution had no difference on growth and yield of endive Plants.

• Journal of the Korean Society of Food Culture
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• v.29 no.6
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• pp.659-667
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• 2014

Fruits are good sources of vitamins, minerals, fiber, and phytochemicals, which are known to reduce serum lipids, oxidative damage, and blood pressure as well as improve blood glucose control. The purpose of this study was to estimate nutrient quality indices of fruits by carrying out a critical analysis of pre-existing methods according to their nutritional compositions. Four methods were used to assess the nutrient indices of 26 fruits, which are frequently consumed by Koreans based on the fourth Korean National Health and Nutrition Examination Survey (2009). Naturally nutrient rich score (NNR), nutrient rich food (NRF), nutrient adequacy score (NAS), and nutrient density score (NDS) were used to calculate nutrient quality indices. The Korean Nutrition Society Food Composition database of fruits based on 100 g edible portions was used. The algorithm of each method included the mean percentage of daily values (Dietary Reference Intakes for Koreans, 2010) for particular nutrients based on consumption of 1,900 kcal/day. The relative score indicated that strawberries, kumquat, and lemon had high nutrient quality indices. In addition, mango, lemon, persimmon, strawberry, apricot, and tangerine fruits are rich in antioxidant nutrients such as ${\beta}$-carotene, vitamin C, vitamin E, and selenium. However, scores of nutrient quality indices did not imply that higher scores of particular fruits are superior. We suggest moderate seasonable consumption a variety of fruits. Our results can be used as a reference for consumers when they choose fruits.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.4
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• pp.269-274
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• 2013

This study is conducted to estimate the nutrient compositions and in-situ ruminal disappearancerates of roughage sources which are commonly used in South Korea. Twelve types of roughage sources are being selected based on surveys from more than 50 farms, and 12 samples from various farms and companies are collected and analyzed for their nutritive components and minerals. Two Hanwoo steers (BW $526{\pm}14$ kg) with ruminal cannula are used to investigate in situ ruminal degradability. Five roughage sources, timothy hay, alfalfa pellet, rice straw, klein grass hay and tall fescue straw, are all selected from 12 roughage sources above for further experiments. Overall, the nutrient components and minerals from the 12 roughage sources have shown low values when comparing with standard tables of feed compositions in Korea. In situ dry matter disappearance rate is recorded as high in order of klein grass, timothy, alfalfa pellet, tall fescue and rice straw. In situ crude protein disappearance rate is high in order of alfalfa pellet, klein grass, timothy, tall fescue and rice straw.

• The Korean Journal of Ecology
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• v.7 no.3
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• pp.109-118
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• 1983

Near future dynamics of water qualities (nutrient concentration) of the Han River was predicted, based on a mathematical model representing the relationship between the nutrient concentration in th river wagter and environmental factors (population density, land-use types, rock compositions and nutrient accumulation) in the basin. The population density and land-use types were forecasted to change distinctly in the downstream area, especially in Seoul City area in 1985~1990 whereas any environmental factor was not expected to change its level significantly in both upstream and middle reaches areas. It was indicated by the model that the nutrients concentration in the up- and mid-streams would keep its level in future as it was, but it would increase drastially in the downstream area. For the preservation of the water qualities in the downstream at least to keep its level as it was in 1980, practical countermeasures were proposed, based on the assessment of the contribution of each environmental factor to the water qualities.

• Korean Journal of Poultry Science
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• v.47 no.2
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• pp.107-114
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• 2020

This study was conducted to investigate the variation in nutrient composition of oilseed meals and to develop prediction equations for amino acid concentrations. Energy and nutrient contents were determined in a total of 1,380 feed ingredient samples including copra byproducts, corn distillers, dried grains with solubles, palm kernel byproducts, and soybean meal. The ingredient samples were imported to the Republic of Korea between 2006 and 2015. Data were analyzed using the MIXED procedure of SAS. The regression procedure of SAS was used to generate the prediction equation for the lysine concentration using the crude protein (CP) concentration as an independent variable. The concentrations of moisture, gross energy, CP, ether extract, crude fiber, ash, calcium, phosphorus, lysine, methionine, cysteine, and threonine in tested oilseed meals differed (P<0.05) depending on producing countries. The prediction equations for amino acid concentrations (% as-is basis) in the oilseed meals are: lysine = -1.08 + 0.080 × CP (root mean square error = 0.244, R² = 0.924, and P<0.001); threonine = -0.297 + 0.044 × CP (root mean square error = 0.099, R² = 0.958, and P<0.001). In conclusion, energy and nutrient compositions vary in the oilseed meals depending on the producing countries. Moreover, the crude protein concentration can be used as a suitable independent variable for estimating lysine and threonine concentrations in the oilseed meals.