• ALGAE
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• v.18 no.2
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• pp.129-134
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• 2003

In order to examine the effects of deep seawater (mesopelagic water in the broad sense) on the growth of macroalgae, the growth and nutrient uptake (nitrate and phosphate) of Ulva sp. (Ulvophyceae, Chlorophyta) were investigated by cultivation in deep seawater (taken from 687 m depth at Yaizu, central Japan, in August 2001), surface seawater (taken from 24 m depth), and a combination of the two. Culture experiments were carried out in a continuous water supply system and an intermittent water supply system, in which aerated 500-mL flasks with 4 discs of Ulva sp. (cut sections of ca. 2 $cm_2$) were cultured at 20$^{\circ}C$ water temperature, 100 $\mu$mol photons $m^{-2}{\cdot}s^{-1}$ light intensity, and a 14:10 light:dark cycle. Nutrient uptake by Ulva sp. was high in all seawater media in both culture systems. The frond area, dry weight, chlorophyll a content, dry weight per unit area, and chlorophyll a content per unit area of Ulva sp. at the end of the experimental period were the highest in deep seawater and the lowest in surface seawater in both culture systems. These values, except for dry weight per unit area and chlorophyll a content per unit area, for each seawater media in the intermittent water supply system were higher than those in the continuous water supply system. We conclude that not only deep seawater as the culture medium but also the seawater supply system is important for effective cultivation of macroalgae.

• Journal of the Korean Society of Food Culture
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• v.14 no.4
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• pp.319-331
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• 1999

This nutritional survey was conducted in February 25, 1999, in order to investigate the nutritional knowledge, dietary attitudes and nutrient intakes of dietitians living in Kangwon area. Subjects consisted of 250 dietitians, with 184 in school food service, 14 in hospital food service and 52 in institution food service. Data were analyzed for frequencies, means, t-test, $x^2$-test, ANOVA and Pearson correlation using SPSS PC Package. The results obtained are summarized as follows: The average nutritional knowledge score was 10.15 out of possible 15 points, and dietary attitude score was 67.93 out of 100 points. The correlation between nutritional knowledge score and dietary attitude score was lowly(${\gamma}=-0.25$). Nutrients consumed below the Korean RDA were energy (78.77%), Ca(90.5%), Fe(83.70%) and nutrients consumed above the Korean RDA were protein(110.83%), P(140.21%), vit.A(163.94%), $vit.B_2$(126.37%), niacin(121.12%) and vit C(231.86%). Carbohydrate, protein and fat ratio on energy composition was 63%:17%:20%. The nutrient density among 3 groups of dietitian was not significantly different.

• Journal of the Korean Society of Food Culture
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• v.22 no.6
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• pp.841-847
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• 2007

This study was conducted to investigate on bone density and nutrient intake of university students in Seoul area. Nutrient intake data were obtained by using the 24-hour recall method to evaluate the usual diet of the subjects. BQI(bone quality index) of the subjects was measured by an Quantitative Ultrasound (QUS). The results are summarized as follows: The average height, weight, BMI of the male and female student were 173.3 cm, 68.5 kg, 22.7; 161.4 cm, 54.2 kg, 20.8, respectively. The BQI and Z-score of the subjects were 99.50, -0.69 in male student group, and 82.6, -1.15 in female student group, respectively. Normal, osteopenia and osteoporosis percentage by bone status were 73.8%, 24.9%, 1.3% in male student group, and 39.8%, 57.6%, 2.6% in female student group, respectively. Energy intake of male and female group were 71.7%, 79.1% of EER(estimated energy requirement) respectively. Fiber, Ca, Vit $B_2$, niacin, folic acid, Vit C intake were less than RI(recommended intake) and protein, phosphorus intake were higher than RI in subjects. Nutrient intake were not significantly related with BQI in male and female groups generally.

• Korean Journal of Environmental Agriculture
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• v.9 no.1
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• pp.53-59
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• 1990

Root zone environments in hydroponics are very important factors in crop growth, development and quality. In Korea, improvement of root zone temperature is required because of the continental climate. Therefore, this investigation was carried out to clarify the difference of root zone environments in different hydroponic systems under different climates. Tomato plants were grown in nutrient solutions at Seoul City University and Allen Cooper's. Hydroponic systems in this experiment were aeroponics, nutrient film technique(NFT), rockwool culture, sand culture and smoked rice hull culture(SRH). The decrease in temperature rapidly occured in sand culture while slowly in rockwool culture in low air temperature periods. The internal temperature of substrates of hydroponic bed were slightly changed in rockwool culture under high air temperature periods, while the duration of high temperature was longest in NFT. Electrical conductivity and pH of nutrient solution showed great changes in rockwool and aeroponics. Along the bed, the content of dissolved oxygen in nutrient solution had a tendency to decrease in NFT and DFT(Deep flow technique), while didn`t a change with aeroponics. Root activity measured by triphenyl tetrazolium chloride (TTC) was highest with aeroponics, followed by rockwool culture and NFT.

• Horticultural Science & Technology
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• v.16 no.1
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• pp.37-39
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• 1998

This study was carried out to investigate the effects of nutrient solution concentration, irrigation frequency on growth, flowering, and cut flower longevity of Dendranthema grandiflorum (Ramat.) Kitamura 'Shuhouno-chikara' hydroponically grown in perlite media. Not only stem length but also mineral contents of each plant organ in nutrient solution culture were much higher than those in soil culture. 1/2S of nutrient solution was good at early stage, but 1S of nutrient solution was better as chrysanthemum growth progressed. Among different concentrations of nutrient solution, mineral contents of each plant part showed no significant difference. 1S treatment of nutrient solution increased the vase life by 3 days than 2S treatment. The growth and mineral contents of each plant organ were great in plants irrigated 8 times a day, because of high moisture contents of medium and high water availability, followed by more frequent nutrient replenishment near roots. There was no correlation between nutrient solution concentration and vase life of cut flower grown in nutrient solution culture. Cut flowers irrigated twice per day had the longer vase life than other treatments (4, 8 times).

• Journal of Bio-Environment Control
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• v.10 no.2
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• pp.125-131
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• 2001

The objective of this study was to estimate the amount of nutrient and water taken up at different growth stages by cucumber (Cucumis sativus L. cv. Eunsung Backdadagi) grown in a closed substrate culture system. The amount of nutrient solution absorbed increased in proportion to days from planting at the first stage of growth and depended on the level of radiation after the mid stage of growth. After the mid growth stage, the amount of nutrient solution absorption was maintained at 80-100 mg.MJ$^{-1}$ . Total amount of absorbed inorganic ions except S increased since the nutrient solution absorption increased with the level of radiation, although the absorption rate of each inorganic ion declined. A highly significant correlation ($R^2$>0.9) was found between amount of inorganic ions absorbed and days after planting, LAI, total dry weight and leaf dry weight, but not with CGR. Correlation coefficient between days after planting and the amount of nutrient solution absorbed per unit radiation level was 0.92. Correlation coefficient between leaf area an the amount of nutrient solution absorbed per unit radiation level was 0.97. Regression of the amount of nutrient solution absorbed per unit radiation level and nutrient ions uptake showed a high significance ($R^2$>0.9).

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.68-73
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• 1995

This study was carried out to investigate the effect of the concentration of nutrient solution on growth of tomato(Lrcopersicon esculentum Mill. cv. seokwang) in substrate culture. The substrates used in the experiment were perlite, vermiculite, and peatmoss. Tomato plants were treated with different concentrations of nutrient solution, viz. 0.5, 1.0, 2.0, 3.0, and 5.0mS/cm at seedling stage and transferred to different treatments, 1.0, 2.0, and 3.0mS/cm after transplanting in each substrate. Total fruit number, total yield, marketable fruit number, and marketable yield were much higher at 2.0-3.0mS/cm than at 1.0mS/cm in all three substrate culture. The percentage of malformed fruit was in order of peatmoss>perlite> vermiculite and Vitamin C content was vermiculite> perlite> peatmoss. In all three substrate culture, high marketable yield was shown when tomato plants grew with concentration of 2.0-5.0mS/cm at seedling stage and 2.0-3.0mS/cm after transplanting. The concentrations of nutrient solution after transplanting as well as at seedling stage had a great influence on total yield, marketable yield, and soluble solids. However total and marketable fruit number were considerably affected by the concentrations of nutrient solution after transplanting.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.74-82
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• 2001

The effects of Al and Mn concentration on dry weight growth, nutrient status and gas exchange rates of 2-Year-old Japanese red pine(Pinus densiflora) seedlings grown in a nutrient culture solution were investigated. Al was added as aluminum chloride at 0, 10, 30 or 60ppm, and Mn was added as manganese chloride at 0, 30 or 60ppm to the nutrient culture solution. The pH of the solution was maintained at 4.0 by adding HCl or NaOH solution. The seedlings were transplanted into the nutrient culture solution, then they were grown in a greenhouse for 90 days. The interactive effects of Al and Mn on the dry weight growth of the seedlings were not significant. There were a main effect of Al or Mn on the dry weight growth and element concentrations of the seedlings. The treatment with Al of ${\geq}10ppm$ or that with Mn of 60ppm induced a significant reduction in the dry weight growth, which indicates that the effect of Al is stronger than that of Mn. The chlorophyll content of needles was not affected by Al treatment, but was significantly reduced by treatment with Mn of 60ppm. Furthermore, the treatment with Al of 60ppm or that with Mn of ${\geq}30ppm$ caused a significant reduction in the dark respiration rate of the roots. The net photosynthetic rate of the seedlings reduced with increasing the concentration of Al or Mn in the nutrient culture solution, which suggests that Al or Mn induced reductions in the relative growth rate(RGR) and net assimilation rate(NAR) of the seedlings were mainly due to the decrease of net photosynthesis.

• Food Quality and Culture
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• v.2 no.2
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• pp.80-84
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• 2008

In this study, sixth grade school children in the Guri area were surveyed via questionnaire regarding their sociodemographic characteristics, snacking patterns, and intakes of different food groups and sugared snacks. Students with employed mothers had more frequent snacking events and were more dependent on store-purchased snacks compared to those having an unemployed mother. A high consumption of snack sugar was associated with a higher dietary diversity score. There was a positive relationship between snack sugar intake and the intakes of meat and dairy products and foods in the oil and nut group, respectively. A high snack sugar intake had a negative effect on fruit intake. Specific nutrient intake data will be required before conclusions can be made on whether nutrient imbalances are a concern in elementary school children having sweet snacks. Yet, the current data indicate that an increased snack sugar intake can decrease fruit intake, which could result in certain nutrient deficits. Specific dietary guidance may be necessary to address the snacking habits of elementary school children.

• Journal of the Korean Society of Food Culture
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• v.5 no.4
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• pp.481-485
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• 1990

This study is designed to forecast the characteristics in food consumption patterns under per capita GNP growth. Ordinary least square(OLS)method was employed as analyzing technique. Equation was $Y=a_0+a_1X$, in which X was per capita GNP and Y were Engel coefficient, food supply, energy supply, nutrient intake and ratio of self-supply of food. The result obtained indicates that the intake of nutrient such as protein and fat will be increased, and wheat, corn and legume are expected to be imported wholly due to lower ratio of self-supply, and rice will be over-supplied continually. Therefore, the relevant policy of government must be established in the field of supply and demand of food, and the research of sound national health should be done.