• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.2-2
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• 2018

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.2
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• pp.120-126
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• 2014

An accurate analysis of nutrient balance in different cropping systems is necessary for improving soil fertilities, causing higher crop yields and quality. This study was carried out to investigate the nutrient balance, changes in soil properties, and their effects on crop yield in long-term field cultivation under mono- and rotation-cropping systems (MCS and RCS, respectively). The analytical results of the soil properties showed that the application of mineral fertilizers alone in the MCS leads the reduction of soil CEC, exchangeable Ca, and microbial biomass C and N. Compared with the MCS of soybean, the RCS of soybean and barley significantly improved the soil properties, which increased crop yield. It might be due to the barley residue added to the RCS soil. Mean nutrient balances for 4 years were -55.9 kg N, +34.7 kg $P_2O_5$, and -0.3 kg $K_2O$ $ha^{-1}$ for the MCS and +19.7 kg N, +107.4 kg $P_2O_5$, and -48.6 kg $K_2O$ $ha^{-1}$ for the RCS, respectively. These nutrient imbalances mean that conventional fertilizer recommendations were inadequate for maintaining soil nutrient balance. From these results, we can conclude that the crop rotation may change comprehensive physical, chemical, and biological soil properties. These changes could affect the nutrient balance and then the crop yield.

• The Korean Journal of Community Living Science
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• v.13 no.2
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• pp.37-51
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• 2002

This study was performed to investigate the degree of different stresses and to search the influence of food habit and nutrient intakes at stress situation in university students and secondary school teachers. The data was collected by questionnaire method and searched nutrient intakes by 24 hours recall. The subjects were 282 students and 152 high school teacher in Kyunggi do. Physical status was no difference with two groups. Energy intake of teachers was lower than that of students, but the intakes of vitamin A and C were high in teachers' group. The university students had more stress situation than teachers in almost kind of stresses except overload stress. Self-diagnosed dietary habits were better in the group of teacher. Especially smoke and alcohol drink behavior were correlated with nutrient intakes in male teachers and students. The quantity of nutrient of nutrient intakes was correlated with different kind of stress. The stress of life event was correlated with the intakes of carbohydrate, minerals, thiamin and riboflavin, and the deprivation was with iron and vitamin A in teachers' group. The intake of almost nutrients was correlated with the stress of noise in students' group. By the analysis of stepwise multiple regression, although the $R^2$ values were very low, vitamin C intake was influenced in the factor at the stress of life events($R^2$=0.025), self-efface($R^2$=0.030) and noise($R^2$=0.020), thiamin was at food induced stress ($R^2$=0.021) and vitamin A was at the stress of type A behavior($R^2$=0.022) and anxiety response($R^2$=0.014). Therefore, we could concluded that different kind of stresses were influenced in dietary behavior and nutrient intakes. More research would be needed at the aspects of health promotion in the stressful situation of modern society.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.4
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• pp.39-50
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• 2002

Field experiment was performed to investigate water and nutrient mass balances in paddy field with groundwater irrigation from May to October, 2001. The total water inflow was about 1,183mm in which rainfall, overflow from upstream paddy, and groundwater irrigation accounted for 43, 30, and 27%, respectively. Notice that the precipitation of the study period was less than the average annual precipitation. The total drainage was almost balanced with the inflow and more than half of it was occurred by surface drainage. From the nutrient mass balance analysis, the T-P output (17.56kg/ha) was estimated slightly lower than the input (20.90kg/ha) and the T-N output (130.41kg/ha) was slightly greater than the input(129.24kg/ha). However, the difference was within the expectation and the nutrient mass was thought to be balanced considering uncertainties in field experiment and other activities not included in the study such as algae and soil microorganisms. The surface discharge of nutrient, which was about 10% of total nutrient output, was mainly affected by fertilization and rainfall runoff. Therefore, prudent surface drainage plan might be necessary particularly for the fertilization period to prevent degradation of receiving water quality. The study was performed under abnormally low rainfall compared to the average annual rainfall record, and further monitoring in diverse rainfalls and irrigation methods is recommended to estimate nutrient behavior in the paddy field more reasonably.

• Mycobiology
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• v.48 no.5
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• pp.410-417
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• 2020

Fungal ecological interactions play a key role in structuring community assemblages. These associations may involve both antagonistic and synergistic relationships, which are commonly influenced by abiotic factors such as nutrient conditions. However, information for extreme, oligotrophic systems remain poor. Herein, interactions among key members of the aquatic transient fungal community (Aspergillus niger, Cladosporium sp., and Coprinellus micaceus) of a low-nutrient freshwater system in the Cuatro Ci enegas Basin, Mexico were studied. Pairwise interaction bioassays were explored in vitro under different nutrient conditions, including carbohydrates-rich, carbohydrates and amino peptides-rich, and low nutrients. Our results indicated that antagonistic patterns prevail among the studied taxa. However, nutrient-dependent changes were observed in Cladosporium sp. shifting to synergy under carbohydrates-rich conditions, suggesting changes in the fungal community composition as a result of nutrient enrichment. Remarkably, our findings contrast with previous work demonstrating mainly synergistic interactions between our tested fungal isolates and co-occurring autochthonous bacteria (Aeromonas spp. and Vibrio sp.) under low-nutrient conditions. This observation may indicate that bacteria and fungi exhibit distinct community-level responses, driven by nutrient conditions. This contributes to the knowledge of fungal community dynamics and interspecific interactions in an oligotrophic ecosystem, highlighting the relevance of nutrient-based shifts and antagonistic interactions in ecosystem dynamics.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.1
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• pp.29-35
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• 2015

Dissolved nutrients in seawater are recognized as an essential biogeochemical factor for detecting global environmental changes. The importance of nutrient reference material for seawater has been increased greatly for the comparison of nutrient data, measured in different time and space in global ocean by various researchers with different levels in nutrient analysis skill. In this study, we described the homogeneity and stability of nutrient reference material for seawater using natural seawater, collected at a station of Shihwa Lake, at a coastal station near Uljin (surface water), and at a station over the Ulleung Basin (surface water and 1500 m depth water) and sterilized. Based on the homogeneity data, the nutrient reference materials has similar homogeneity compared to other nutrient reference materials. During 3-13 month period, there was no unidirectional trend of increase or decrease in nutrient concentration of newly developed nutrient reference material for seawater. However, a sustained measurement is required to check stability for longer period.

• Journal of Biosystems Engineering
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• v.28 no.4
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• pp.335-342
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• 2003

A simple disposable thick-film potentiometric strip has been developed and evaluated for hydroponics application. The strip consisted of low ion-selective electrodes (ISE) fabricated by screen-printing technology. The electrochemical responses of ion sensors for nitrate, ammonium, potassium, and magnesium were measured with specially designed 16-channel low voltage signal transducers. The analytical characteristics of the sensors were comparable with those of conventional ISE sensors. The thick-film sensors exhibit linear relationships over five concentration decades. The concentration of N $O_3$ - ion in standard solution can be determined by direct potentiometric measurements without any conditioning before measurements. However, measurement of $K^{+}$, N $H_4$$^{+}$, and $Mg^{2+}$ ionic concentrations in nutrient solutions seems not feasible.

• Journal of the Korean Society of Food Culture
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• v.11 no.1
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• pp.61-69
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• 1996

This study was carried on the analysis of food and nutrient intake for elementary school foodservices in Seoul. The survey was conducted through the 200 menus submitted by the 5 elementary schools in Seoul. Energy and all nutrient intakes exceeded the Recommended Daily Allowances of Koreans. Carbohydrate provided 56.32% of total energy intake; protein accounted for 16.06%; fat provided 27.62%. Total intake of food was 549 g on the average, which consisted of 90.04 g cereals, 130.17 g vegetables, 31.56 g meats, 21.63 g fishes and 200.00 g milks. The basic menu patterns were Rice+Soup (or Stew)+Kimchi, and 2 other side dishes including milk. These data underscore the necessity of developing the 'Standard Menu' for elementary school foodservices.

• Journal of Environmental Impact Assessment
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• v.15 no.2
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• pp.129-138
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• 2006

The measurements of nutrient and runoff in 4 streams have been performed before and after the rainfall in order to estimate nutrient loads in the Yongdam reservoir. The equations for the relationship between the flow and the loads in each stream could be estimated by the regression analysis. R2 of TN showed the range from 0.95 to 0.99 and the range of R2 for TP was 0.90~0.95 based on the results of the regression analyses. In 2002, total loadings from the upstream to the Yongdam reservoir were TN 1,175 ton/year, TP 69 ton/year. There were 64.9% of TN and 72.3% of TP during 4 months as the flood season. Due to the rainfall, the load of TP was higher than one of TN in Yongdam reservoir.

• Journal of the Korean Society of Food Culture
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• v.16 no.5
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• pp.492-503
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• 2001

The purpose of this study was to compare nutritional intakes of college students in Seoul and Yanbian by ethnic : Korean, Korean-Chinese, Chinese. The questionnaire were applied to individual interviewing method. Statisticai data analysis was completed by SAS 8.0 package program for t-test, ANOVA and multiple comparison. The results of this study were as follows. Average energy intake per day was high in Korean-Chinese. Nutrient Adequacy Ratio(NAR) was highest in iron and lowest in zinc. Mean Adequacy Ratio(MAR) score was $0.68{\sim}0.85$ for each group. The indexes of nutritional quality(INQ) were over 1.0 for most nutrients except 0.41 of zinc and 0.76 of calcium. Average energy intake ranked high in Korean-Chinese, Korean and Chinese.