• Journal of Biosystems Engineering
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• v.4 no.2
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• pp.64-64
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• 1979

Low-temperature drying systems have been extensively used for drying cereal grain such as shelled corn and wheat. Since the 1973 energy crisis, many researches have been conducted to apply solar energy as supplemental heat to natural air drying systems. However, little research on rough rice drying has been done in this area, especially very little in Korea. In designing a solar drying system, quality loss, airflow requirements, temperature rise of drying air, fan power and energy requirements should be throughly studied. The factors affecting solar drying systems are airflow rate, initial moisture content, the amount of heat added to drying air, fan operation method and the weather conditions. The major objectives of this study were to analyze the effects of the performance factors and determine design parameters such as airflow requirements, optimum bed depth, optimum temperature rise of drying air, fan operation method and collector size. Three hourly observations based on the 4-year weather data in Chuncheon area were used to simulate rough rice drying. The results can be summarized as follows: 1. The results of the statistical analysis indicated that the experimental and predicted values of the temperature rise of the air passing through the collector agreed well.2. Equilibrium moisture content was affected a little by airflow rate, but affected mainly by the amount of heat added, to drying air. Equilibrium moisture content ranged from 12.2 to 13.2 percent wet basis for the continuous fan operation, from 10.4 to 11.7 percent wet basis for the intermittent fan operation respectively, in range of 1. 6 to 5. 9 degrees Centigrade average temperature rise of drying air.3. Average moisture content when top layer was dried to 15 percent wet basis ranged from 13.1 to 13.9 percent wet basis for the continuous fan operation, from 11.9 to 13.4 percent wet basis for the intermittent fan operation respectively, in the range of 1.6 to 5.9 degrees Centigrade average temperature rise of drying air and 18 to 24 percent wet basis initial moisture content. The results indicated that grain was overdried with the intermittent fan operation in any range of temperature rise of drying air. Therefore, the continuous fan operation is usually more effective than the intermittent fan operation considering the overdrying.4. For the continuous fan operation, the average temperature rise of drying air may be limited to 2.2 to 3. 3 degrees Centigrade considering safe storage moisture level of 13.5 to 14 perceut wet basis.5. Required drying time decrease ranged from 40 to 50 percent each time the airflow rate was doubled and from 3.9 to 4.3 percent approximately for each one degrees Centigrade in average temperature rise of drying air regardless of the fan operation methods. Therefore, the average temperature rise of drying air had a little effect on required drying time.6. Required drying time increase ranged from 18 to 30 percent approximately for each 2 percent increase in initial moisture content regardless of the fan operation methods, in the range of 18 to 24 percent moisture.7. The intermittent fan operation showed about 36 to 42 percent decrease in required drying time as compared with the continuous fan operation.8. Drymatter loss decrease ranged from 34 to 46 percent each time the airflow rate was doubled and from 2 to 3 percent approximately for each one degrees Centigrade in average temperature rise of drying air, regardless of the fan operation methods. Therefore, the average temperature rise of drying air had a little effect on drymatter loss. 9. Drymatter loss increase ranged from 50 to 78 percent approximately for each 2 percent increase in initial moisture content, in the range of 18 to 24 percent moisture. 10. The intermittent fan operation: showed about 40 to 50 percent increase in drymatter loss as compared with the continuous fan operation and the increasing rate was higher at high level of initial moisture and average temperature rise.11. Year-to-year weather conditions had a little effect on required drying time and drymatter loss.12. The equations for estimating time required to dry top layer to 16 and 1536 wet basis and drymatter loss were derived as functions of the performance factors. by the least square method.13. Minimum airflow rates based on 0.5 percent drymatter loss were estimated.Minimum airflow rates for the intermittent fan operation were approximately 1.5 to 1.8 times as much as compared with the continuous fan operation, but a few differences among year-to-year.14. Required fan horsepower and energy for the intermittent fan operation were3. 7 and 1. 5 times respectively as much as compared with the continuous fan operation.15. The continuous fan operation may be more effective than the intermittent fan operation considering overdrying, fan horsepower requirements, and energy use.16. A method for estimating the required collection area of flat-plate solar collector using average temperature rise and airflow rate was presented.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.113-122
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• 2003

Net and metabolizable energy requirements for maintenance of Hanwoo (Korean native cattle) bulls were estimated in twenty-eight fasting metabolism trials using seven different feeds at four stages of body weight(100, 200, 300 and 400kg). Three cattle for each of twenty-eight trials fed at a level of maintenance energy requirement were housed in metabolic stalls during the 5 days of collection period. Thereafter, during the 2 days of respiration period the heat production was measured by indirect calorimetry using respiratory chamber. After finishing the respiratory metabolism trials under the maintenance level, experimental animals were fasted for 5 days and were measured heat production by indirect calorimetry using respiratory chamber. Seven different feeds were: 1) mixed ration of concentrate and rice straw, 2) mixed ration of concentrate and mixed grass hay, 3) mixed ration of concentrate and corn silage, 4) rice straw alone, 5) mixed grass hay alone, 6) corn silage alone, 7) concentrate alone. Fasting heat production were 66.05/$W^{0.75}$ at 100kg of body weight and 60~63kcal/$W^{0.75}$ at 200~400kg of body weight. When subtracting heat loss by muscular work from the fasting heat production, basal metabolic rate was 55.92kcal/$W^{0.75}$. The average values of NEm requirements were obtained by adding urinary energy excretion to the basal metabolic rates were 69.1, 62.1, 65.8 and 64.4kcal/$W^{0.75}$ for the four stages of body weight, respectively. The ME requirement for maintenance could be calculated using retained energy and the efficiency of utilization of ME for net energy. The ME requirement for maintenance thus obtained was 102.69kcal/$W^{0.75}$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.1
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• pp.238-246
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• 1998

Surface residual stresses as well as wall thickness and ovality changes after U-bending process on UNS N06690 row-1 heat exchanger tubes, were estimated. Surface residual stresses were measured by Hole Drilling Method(HDM), calculating the stresses from relieved strains of 3 rosette strain gages. After bending of the tubes, dimensional tolerances for wall thickness and ovality were satisfied with ASTM requirements. Residual stresses at the extrados were introduced with compressive stress(-) by bending operations, and its maximum value reached-319 MPa in axial direction at ${\phi}=0^{\circ}$ in position. Tensile residual stresses(+) of ${\sigma}_zz=45$ MPa,${\sigma}_zz=25$ MPa were introduced in the intrados surface at position of ${\phi}=0^{\circ}$ Maximum tensile residual stress of 170 MPa was detected on the flank side at position of ,${\phi}=95^{\circ}$i.e., at apex region. It appeared that higher stress gradients were generated at the irregular transition regions. In the trend of residual stress changes with U-bend position, the extrados is related with the changes of ovality and the intrados is related with the changes of wall thickness.

• Korean Journal of Community Nutrition
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• v.15 no.1
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• pp.61-72
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• 2010

The purpose of this study was to evaluate the effect of a weight control program on anthropometric values, serum lipid profiles and nutrient intakes. The subjects of this study were 38 obese children (boy : 17, girl : 21) with obesity index over 120%. The weight control program for obese children included nutritional education (50 min) and exercise (50 min) for 10 weeks. The nutrition intakes of the children were surveyed before and after the weight control program by 24hr recall test. The BMI, R$\ddot{o}$hrer Index, Obesity Index, WHR (Waist - Hip ratio) and body fat(%) were significantly decreased after completion of the weight control program. The total cholesterol and HDL-cholesterol of subjects were significantly increased after the weight control program. Distribution of serum lipid profiles was slightly changed. The energy intakes were significantly decreased (p < 0.001). from 1760.8 kcal to 1435.2 kcal. In addition, the intakes of P, Zn, retinol, vitamin $B_1$, vitamin $B_2$, vitamin E and niacin were significantly decreased. while intakes of vitamin C and folate were increased. Calcium and folic acid were upper 25% of subjects, under EAR(Estimated Average Requirements) intake before the weight control program. The distribution of energy intakes was significantly changed into positive status; fat percentage was decreased 26.3% to 22.1% (p < 0.01). Carbohydrate was increased 58.6% to 61.2% (p < 0.05). Meal distribution of energy intakes was changed; calorie percentage from lunch significantly increased from 32.2% to 38.3%. Calorie percentage from snack significantly decreased from 17.7% to 13.5%. In conclusion, weight control program for 10 weeks is effective in obesity index and nutrient intakes although serum lipid values were a little changed.

• Korean Journal of Community Nutrition
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• v.16 no.2
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• pp.253-264
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• 2011

The objectives of this study were to investigate the current status of the Korean government-funded meal support program for low-income children through convenience stores and to evaluate the nutritional quality of the meal items available under the program. The POS data of three convenient stores where children had used their electronic meal cards most often in Seoul during January 2010 and the kinds and amounts of ingredients of the meal items available to the children were obtained from the headquarter of the convenient stores. A total of 5,081 transactions by 693 children included in the POS data was analyzed. In addition, nutritional contents of meal items, which were meal boxes (11 kinds), kimbab (13 kinds), rice balls (27 kinds), inari sushi (1 kind), and sandwiches (26 kinds), were analyzed with Can Pro 3.0. The results showed that children had purchased flavored-milk products most often. Children tended to purchase meal items together with drinks (60.9% of transactions), but some purchased drinks (27.6%) or meal items only (11.5%). Except for meal boxes, none of the meal items satisfied 1/3 of Estimated Energy Requirements of the 9-11 year-old boys per day. The average energy contents of different kinds of meal boxes, kimbabs, rice balls, and sandwiches were 619, 357, 200, and 380 kcal, respectively, and the energy content of a package of Inari sushi was 457 kcal. Vitamin C amount was found to be deficient in all the meal items, compared to 1/3 of Recommended Intake of the 9-11 year-old boys per day. The results of this study could be useful to develop nutritionally appropriate meal items for the convenient stores participating in the government-funded meal support program for children from lowincome families.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.9
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• pp.1101-1105
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• 2014

Ocean Thermal Energy Conversion(OTEC) which uses the temperature difference between warm surface sea-water and cold deep sea-water to produce electric power is the promising technology. OTEC is able to be utilized as the $CO_2$ reducing technology by using the consistent temperature differential, while the system efficiency is very low. Thus, the design and development of a efficient turbine is essential to improve the system efficiency for OTEC. In this study, a 100kW-class radial inflow turbine using R32 was designed for OTEC and this turbine's performance was estimated by analysis of CFD. According as the simulation results, turbine's geometry was corrected. The radial inflow turbine satisfying the requirements is designed by the repeated attempts.

• Nutrition Research and Practice
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• v.13 no.1
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• pp.32-40
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• 2019

BACKGOUND/OBJECTIVES: This study investigated nutritional status of the elderly with dementia in a care facility with the aim of improving the meal quality of the facility. SUBJECTS/METHODS: Data were collected from 30 dementia patients aged more than 65 years in a long-term care facility in Hongseong. The data were obtained from questionnaires and medical records. The food intake data was obtained using food photographs and the nutrient intakes were calculated using the CAN-Pro 5.0. The data were compared with the dietary reference intakes for Koreans (KDRIs). The nutrient density, diet quality such as nutrient adequacy ratio (NAR), mean adequacy ratio (MAR), and index of nutritional quality (INQ), as well as dietary diversity score (DDS) were evaluated. The data were analyzed using SPSS statistical programs. RESULTS: The average daily energy intakes for men and women were much lower than the estimated energy requirements of the KDRIs. The average intakes of energy and most nutrients in the general diet group were significantly higher than those of the other two groups. Significant differences in diet quality and diet diversity were observed according to the meal type groups. The NARs of some minerals (calcium, iron, and zinc) and vitamins (vitamin $B_6$ and folic acid) were less than 0.5 in all study groups. The NARs of protein, iron and MAR of the general diet group were significantly higher than those of the liquid diet group. The DDS scores of meats, fruits and diary food group were very low in all meal type groups, meaning that the diet qualities of the study subjects were not appropriate in all meal type groups. CONCLUSIONS: The food intakes of the study groups showed some limitations by a direct comparison with KDRIs because of the very low physical activities of the study subjects. The diet quality and diet diversity indices suggest the need for improvements in the nutritional quality in all types of diet. Overall, new intervention strategies targeting facility residents with dementia in Korea are needed as soon as possible.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.123-130
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• 2003

Metabolizable energy requirements for maintenance (MEm) of Hanwoo bulls were estimated in twelves metabolism trials using three different feeds at four stages of body weight(100, 200, 300 and 400kg). Three feeds were composed of 1) concentrates and rice straw, 2) concentrates and mixed grass hay, 3) concentrates and corn silage, respectively. Three energy levels were 1) maintenance (M) requirement, 2) 1.5 ${\times}$ M, and 3) 2.0 ${\times}$ M. All bulls were received 60% of their energy from concentrates and 40% form roughages. Three cattle for each trials fed different energy level were housed in metabolism stalls during the 5days of collection period, a total collection of feces and urine. Thereafter, during the 2days of respiration period the heat production was measured by indirect calorimetry using respiratory chamber. MEm were 99.80, 94.48, 94.80, and 97.68 kcal/W0.75 at 100, 200, 300 and 400kg. Mean value of MEm and efficiency of utilization ME for retained energy(Kg) were 95.80 kcal/W0.75 and 0.44.

• Water for future
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• v.26 no.2
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• pp.89-97
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• 1993

For the system benefit optimization by considering risk or reliability from a multiple reservoir system using the Monte Carlo technique, many stochastically generated inflow series have to be used for the system analysis. In this study, the stochastically generated inflow series for the multiple reservoir system operation are preprocessed according to the considered system objectives and operating time periods. Through this procedure, several representative inflow series which have discrete probability levels and operation horizons are selected among the thousands of generated inflows. Then a deterministic optimization technique is applied to the power energy estimation from the Han River Reservoirs System which considers five reservoirs in the study. It took much lower computational requirements then using the original Monte Carlo Technique, even though estimated result was almost similar.

• Korean Journal of Community Nutrition
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• v.15 no.3
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• pp.297-307
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• 2010

This study was intended to investigate the relation between nutrient status and food diversity of elementary school students in Daegu-Kyungpook area. The subjects were 164 elementary school students (82 boys, 82 girls) who participated in "Dietary Intake Survey of Infants, Children and Adolescents" conducted by Korea Food & Drug Administration and Korea Health Industry Development Institute. We analyzed the nutritional status for two non-consecutive days by 24 hour recall method. Adequacy of dietary intake was evaluated by the proportion of subjects consuming nutrients less than Estimated Average Requirements (EAR). Food diversity was compared by using Dietary Diversity Score (DDS) and Dietary Variety Score (DVS). Nutrients intake was significantly higher in boys than girls. Subjects who consumed all food groups showed higher intake of energy and other nutrients. Boys maintained better diet quality than girls, measured by Dietary Diversity Score (DDS) as well as Dietary Variety Score (DVS). Based on these results, nutrition education for elementary school students should focus on the importance of consuming all food groups with more attention for girls.