• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.918-925
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• 2008

Controlling the light energy and major nutrients is important for high cell density culture of cyanobacterial cells. The growth phase of Anabaena variabilis can be divided into an exponential growth phase and a deceleration phase. In this study, the cell growth in the deceleration phase showed a linear growth pattern. Both the period of the exponential growth phase and the average cell growth rate in the deceleration phase increased by controlling the light intensity. To control the light intensity, the specific irradiation rate was maintained above $10\;{\mu}mol/s/g$ dry cell by increasing the incident light intensity stepwise. The final cell density increased by controlling the nutrient supply. For the control of the nutrient supply, nitrate, phosphate, and sulfate were intermittently added based on the growth yield, along with the combined control of light intensity and nutrient concentration. Under these control conditions, both final cell concentration and cell productivity increased, to 8.2 g/l and 1.9 g/l/day, respectively.

• Journal of the Korean Dietetic Association
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• v.25 no.2
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• pp.115-128
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• 2019

This study evaluated the nutrient intake with increasing coffee consumption for 403 adults aged over 30 years in Korea. The 403 subjects were national health screening examinees, who visited Sahmyook Seoul Hospital's Comprehensive Check-up Center between 2017.11.01 and 2018.12.18. The subjects were asked to answer questionnaires covering a 24-hour recall fluid and dietary intake before the health examination. The research ethics council of Sahmyook University (2-7001793-AB-N-012019036HR) approved this study. Coffee consumption exceeding two servings daily was more likely in males, in those aged between 30 and 40 years, and in the smoking, drinking, non-exercise, non-breakfast groups compared to each counterpart. The correlation between the coffee consumption frequency and current nutrient density showed negative correlations in most micronutrients. The mean nutrient density decreased gradually with increasing coffee consumption (<1 serving daily, ${\leq}1{\sim}2$ servings daily, >2 servings daily) in the ANOVA analysis. Therefore, the progressive adverse health effects of excessive coffee consumption needs to be researched further, and a daily total caffeine limit should be suggested in education of the nation levels.

• Korean Journal of Human Ecology
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• v.3 no.1
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• pp.25-39
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• 2000

This study investigated the nutrient contents, nutrient density. and food group intake patterns of elementary school lunch programs in Kesngju. Four hundred students from four elementary schools participated in this study. Menus served in 60 schools on a weekly basis during each season were analyzed. Parents regarded hygiene as the most important factor in their children's diet. but they showed little concern for the necessity of nutrition education in the school curriculum. Parents considered that the most significant benefit of their children eating school lunches was to reduce unbalanced diets. On the other hand. children considered to be able to be on intimate terms with their friends as the greatest benefit of the school lunch program. The contents and nutrient densities of the meals provided were higher than those calculated from the Korean RDA. However, the content and nutrient density of iron were lower than those calculated from the RDA for 10 to 12 year old girls. The content of sodium was very high. Therefore the nutritionists should consider the Iron and cut down the amount of sodium. The 91.7% of 1,200 meals served contained more than four food groups and the school lunch program provided a sufficient variety of foods. In conclusion. the quality of nutrition in meals served by school lunch programs was considered satisfactory overall.

• Journal of the Korean Dietetic Association
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• v.12 no.1
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• pp.10-17
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• 2006

The purpose of this study was to examine the correlation between nutrient intakes and bone mineral density in female university students. A total 27 female university students were measured the anthropometric characteristics, dietary intake and the bone mineral density of carpus using DEXA. The average age, height, weight, % body fat, WHR, and BMI of the subjects were 22.7 years, 161.5 cm, 57.0 kg, 29.9%, 0.8, 21.8 kg/$m^2$, respectively. Bone mineral density of ultradis and distal carpus as T-value were -1.5 and -0.4, respectively. The daily energy intake of the subjects was 1589.0kcal. And the intakes of energy, calcium, iron, zinc, vitamin $B_2$, and folic acid did not meet the Korean RDAs. The daily total food intake of the subjects was 1011.0g and food intake from cereals and vegetables was high. The major food groups of mineral intake were vegetables/cereals/milks/fishes for calcium, cereals/meat/vegetables/fishes for phosphorus, cereals/vegetables/meats for iron, seasonings/vegetables/cereals for sodium, vegetables/cereals/seasonings for potassium, and cereals/meats for zinc. The body weight and body mass index were significantly positive correlated to the bone mineral density of average carpus, respectively. The intakes of animal calcium and vitamin $B_2$ were significantly negative correlated to the bone mineral density of average carpus, respectively. In conclusion, bone mineral density in carpus and nutrient intakes of some female university students were low. Therefore, health management and the study on relation between bone mineral density in various site and long-term intakes of nutrients in many subjects are required.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.1059-1065
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• 2005

In this study, an nutrient solution control system have been designed and implemented, which controls the density of nutrient and the nutrient supply automatically using embedded real time operating system and fuzzy control algorithm. The factors which affect the growth of crop consist of solar radiation, external temperature, and external humidity. Also, nutrient temperature, electric conductivity(ED, and pH are monitored. According to the surveyed results, a fuzzy control algorithm for nutrient control is developed in order to control the density of nutrient and the nutrient supply. The exclusive embedded controller which consists of an embedded real time operating system, a korean LCD, and a graphic is developed for common users.

• Journal of Environmental Health Sciences
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• v.22 no.3
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• pp.49-55
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• 1996

Water parsley(Oenanthe javanica(Blume) DC) was raised with varying population density(S) in the laboratory aquarium unit to determine the growth equation. The population density was measure after 7 days. The resultant growth curve was well fit to the equation 1/S = A+B (1/S0) with a high correlation coefficient ($R^2$ = 0.999). The maximum specific absorption rate was $9.011 \times 10^{-5}$ kg $NO_x-N/kg$ water parsley$\cdot$day and $1.31 \times 10^{-5}$ kg $PO_4-P/kg$ water parsley$\cdot$day when the average population density was $2.62 kg/m^2$. The relationship between population density and nutrient absorption rate, the absorption rate of $NO_x-N$ was 5.04~5.24 mg/l$\cdot$day when the population density was $7.51~10.0 $mg/m^2\cdot day$ and the absorption rate of $PO_4-P$ was 0.56~0.78 mg/l$\cdot$day when the population density was 5.02~10.0 $kg/m^2\cdot day$. Taking into account the nutrient absorption rate and growth rate, the population density between $7.0 kg/m^2\cdot day$ and $8.0 kg/m^2 \cdot day$ was selected. The removal rate of nutrient was investigated after 7 days culture. Removal rate of $NO_x-N$ was 95.6~99.95% with initial concentration of 35 mg $NO_x-N/l$, and the removal rate of $PO_4-P$ was also high, indicating 80.24~98.9% with initial concentration of 5.95 mg $PO_x-P/l$.

• Journal of Environmental Science International
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• v.11 no.7
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• pp.705-711
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• 2002

In order to determine the factors causing Microcystis spp. bloom in the lower Nakdong River (Mulgum), we prepared wide ranges of pH, nutrient(N, P) concentration and the light through an enclosure experiment far 10days (pH gradient. 6.5, 7.5, 8.5, 9.5; gradient of N, P: ${\frac{1}{2}}DW+{\frac{1}{2}}River$ Water (RW), RW only; four different levels of nutrient addition/day; light: 100, 85, 60, 30, 15% of full sun light). From three days, the difference of Microcystis density in each enclosures was observed. The high density of Microcystis was maintained in the treatments over pH 9.5 and 85% of full sun light. However, in all nutrient treatments, relatively lower cell density than that of pH and light treatments was observed. These results suggested that pH and light input may play more important roles than nutrients in the early development of Microcystis bloom in the eutrophic lower Nakdong River.

• 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.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.6
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• pp.655-662
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• 2005

Body content bone mined density and nutrient intake status of 129 college women in Daegu area are analyze4 The mean age was 23.1 years. Bone mineral density was measured in their right heel by SONOST-2000 ultrasound bone densitometer, and nutrient intake was assessed by a Questionnaire. Diet intake data were obtained by using a 24 hours recall method to evaluate the subject's usual diet. The average energy, Ca, Ee, Zn and folate intakes were 64.2, 47.5, 54.7, 62.9 and $57.4\%$ of RDA, respectively. Ca/P and Ca/Protein ratio were 0.46 and 6.7, respectively. The mean adequacy ratio(MAR), an index of overall dietary quality wag 0.6. The index of nutritional quality was under 1.0 for protein(0.7), vitamin A(0.9), E(0.7), $B_1(0.8)$, niacin(0.8), $B_6(0.6)$ and phosphorus(0.6). The less the protein and energy intake, the less the bone mineral density(p<0.05). The intakes of protein(p<0.05) and that of phosphorus(p<0.001) were positively correlated with bone quality index(BQI). The calcium intake was positively correlated with Z-score(p<0.05). The phosphorus intake was positively correlated with T-score(p<0.001) and Z-score(p<0.0001). In conclusion, this study indicates that nutrient intake of the college women is considerably lower than the RDA. Also the BQI is lower than standard.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.319-325
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• 2021

In this study, we investigated the effects of feeding diets with different levels of energy and nutrient density on the egg quality of laying hens during the pre-peak and peak periods. A total of 192 (Hy-line brown) laying hens were used in a 15-week trial. The hens were randomly allotted to one of four treatments, each with four replicates (12 hens per replication). We assessed the effects of four level of dietary energy (2,710, 2,850, 2,870 and 2,890 kcal/kg) and three levels of nutrient density (Methionine + Cysteine: 0.56%, 0.85%, 0.80% and Crude Protein: 14.5%, 19%, 18%). Differences in the energy and nutrient density contents of diets showed no significant effect (P>0.05) on the average daily gain, average daily feed intake, feed conversion ratio, egg weight, or egg production of hens during the pre-peak and peak periods. However, hens subjected to 2,890 kcal/kg during the pre-peak period were found to lay eggs with significantly thicker shells, and yolk color was found to be significant enhanced in hens fed this diet during the pre-and peak periods. In contrast, we detected no significant effects of dietary energy or nutrient density on the Haugh unit or eggshell strength. In summary, increasing the energy level of diets from 2,710 to 2,890 kcal/kg was found to have positive effects on the shell thickness and yolk color of eggs produced by laying hens.