• Water for future
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• v.6 no.1
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• pp.5-12
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• 1973

A simple regression formula for estimating the lake evaporation rate from the copper-plated pan (diameter 20cm, height 10cm) is derived. A comparison with other formulae indicates that the formula is more accurate than others. An annual map of man evaporation in Korean peninsula has been prepared using the relation. It demonstrates the areal average distribution of mean annual evaporation from a free water surface with no heat storage effect and avected energy owing to differences in the temperature of in-and outflow. The mean annual ratio of the lake to the copper-plated pan evaporation is found to be 0.64. The ratio varies with local conditions from 0.62 to 0.66, and hence it can be considered fairly uniform. However the seasonal variation of the ratio appears to be rather significant. It changes from the lowest of 0.61 to the highest of 0.75.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.833-838
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• 2014

The energy- and time-dependent branching to the competing dissociation paths are studied by theory for coupled unimolecular dissociations of the o-, m-, and p-chlorotoluene radical cations to $C_7{H_7}^+$ (benzylium and tropylium). There are four different paths to $C_7{H_7}^+$, three to the benzylium ion and one to the tropylium ion, and all of them are coupled together. The branching to the multiple paths leads to the multiexponential decay of reactant with the branching ratio depending on both internal energy and time. To gain insights into the multipath branching, we study the detailed kinetics as a function of time and internal energy on the basis of ab inito/RRKM calculations. The number of reaction steps to $C_7{H_7}^+$ is counted for each path. Of the three isomers, the meta mostly goes through the coupling, whereas the para proceeds with little or no coupling. In the beginning, some reactants with high internal energy decay fast to the benzylium ion without any coupling and others rearrange to the other isomers. Later on all three isomers dissociate to the products via long-lived intermediates. Thus, the reactant shows a multiexponential decay and the branching ratio varies with time as the average internal energy decreases with time. The reciprocal of the effective lifetime is taken as the rate constant. The resulting rate-energy curves are in line with experiments. The present results suggest that the coupling between the stable isomers is thermodynamically controlled, whereas the branching to the product is kinetically controlled.

• Korean Journal of Community Nutrition
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• v.27 no.4
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• pp.321-340
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• 2022

Objectives: This study established a practical direction for the prevention and management of metabolic syndrome by evaluating the health status, nutrition intake level, and diet quality according to metabolic syndrome and related drug treatment in Korean adults. Methods: The data from the 2017 KNHANES (Korea National Health and Nutrition Examination Survey) was analyzed. The analysis included 2,978 adults, classified into the normal, metabolic syndrome (MetS), metabolic syndrome with medicines (MetS-M), and without medicines (MetS-noM) groups. The nutrient intake, NAR (nutrient adequacy ratio), INQ (index of nutritional quality), and DDS (dietary diversity score) were analyzed. Results: The mean BMI was significantly higher in the MetS group than in the normal group for all subjects. Subjects of the MetS group tended to consume less energy and major nutrients, while males aged 50 ~ 64 and all females showed less intake of nutrients in the MetS-M group. The energy intake ratio was within 55 ~ 65 : 7~ 20 : 15 ~ 30 of KDRI (Korean Dietary Recommended Intake), but the carbohydrate energy ratio of all subjects aged 50 to 64 was over 65%. The NAR of the major nutrients was lower in the MetS-M group, the average INQ was around 0.8, especially the INQ of calcium and vitamin A was less than 1, and the total DDS score was less than 4 points. Conclusions: This study confirmed that the nutrient intake and diet quality differed among subjects diagnosed with metabolic syndrome and managed with medical care. The intakes of energy and many nutrients, the quality of diets, and the diversity of food groups in the MetS-M group were lower than in the normal group. Therefore, these will be an important basis for establishing a specific direction of diet education for preventing and managing metabolic syndrome according to gender, age, metabolic syndrome, and drug treatment.

• Journal of Nutrition and Health
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• v.31 no.9
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• pp.1457-1467
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• 1998

The relationship between cognitive function and dietary patterns in Korean elderly women was investigated in this study. Twenty-four-hour dietary recall and cognitive function tests were performed in 170 elderly women aged over 60 years. Average age of the subjects was 71 years and the average number of family members was 3.3. Most of the subjects had less than seven years of education and their monthly income was much lower than the Korean average. Most of the subjects engaged in regular exercise and did not indulge in drinking and smoking. The average cognitive function score of the subjects was 58.4. Most of the subjects appeared to consume insufficient amount of food ; average intakes of energy, Ca, iron, vitamin A, and riboflavin were lower than RDA for the elderly. Cognitive function score was positively related to education level and regularity of exercise. Also, cognitive function score had a strong relationship with food intake such as total amounts of foods, fish and shellfish, milk and dairy products, total animal food, fruit, bread and sugar. Energy, protein, Ca, p, riboflavin, and niacin were also shown to have positive relationships to cognitive function score, while carbohydrate caloric ratio had a negative relationship with cognitive function. According to the results of multiple regression analysis, factors that most influenced on cognitive function were education level and riboflavin intake. The subjects who had more than seven years of education had significantly higher cognitive function scores than those with no school education. And cognitive function scores f3r those who consumed more than 2/3 of the RDA for most nutrients were significantly higher than the ones fir the subjects who consumed less than 2/3 of the RDA. These results suggest that proper education and adequate nutrient intake in quantity and quality by achieving food diversity are essential in maintaining cognitive function in later life (Korean J Nutrition 31(9) : 1457-1467, 1998)

• The Korean Journal of Food And Nutrition
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• v.1 no.1
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• pp.13-24
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• 1988

The survey was carried out to obtain some fundmental data to improve the dietary life and to establish the nutritonal education and policy on inhabitants limed in isle area near by demilitarized zone in Korea. For this, 33 families in the area of Kyodong island located at Kanghwa-Gun, Kyungki province were randomly selected. Trained surveyors visited each house to survey the food and nutritional status in summer during 3 days in August, 1987. The results are summarized as follows ; The number of foods they were taking totalled 17 categories and 134 kinds of which 104 kinds were vegetable foods. The average amount of food intake was 1465.3g per person per day, animal food occupied 9.6% only. The intake amount of fruit among vegetable foods, and fishes, shells, milk and eggs among animal foods was lower than the national average. Each proportion of carbohydrates fat and protein to the total energy intake was 70.4%, 9.7% and 19.9%. The foods they used to take a lot were rice, potatoes. cucumbers, cabbage KIMCHIE and YULMOO KIMCHIE in order of their intake amount. The energy intake was 3064 Kcal which is higher than nutritional requirements, and the energy ratio of cereals to the total energy in take is 76%. If the amount of fat intake is fixed to 20% of total energy intake, the amount of fat intake is 68g, but the actual amount of fat intake was only 33g. With an increase of total energy intake, supply of calcium and vitamin A should be increased much more.

• Journal of Nutrition and Health
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• v.33 no.4
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• pp.438-453
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• 2000

The purposes of this study were to estimate nutritional intakes of the long-lived elderly and to obtain the data for establishing dietary guidelines that may be recommended for the general population for the sake of longevity. The subjects of the study were 300 elederly people of age over 85 years living in Kyungpook Sung-Ju area who had no problem in daily living. Four times of food consumption survey were carried out seasonally by the repeated 24-hr recall method for one year. Mean daily energy intakes and RDA percentage of energy intakes of the male and female subjects were estimated as 1222 kcal(67.9%) and 1047 kcal(65.4%) respectively. Mean daily intakes of nutrients were estimated as 38.3g for protein, 287mg for calcium, 5.8mg for iron, 314R.E. for vitamin A, 0.6mg for vitamin B1 and 0.43mg for vitamin B2 The mean RDA percentages of nutrients intake were 64.4% and 59.8% for protein in male and female, 39.8% for Ca, 48.3% for Fe, 44.9% for vitamin A, 60% for vitamin B1, and 35.8% for B2. The average PFC ratio of energy-yielding nutrients throughout the year in male and female were 15.1 : 15.2 : 69.7 and 13.8 : 13.2 : 73.0 respectively. The mean daily intakes of energy and most of nutreints were significantly high in winter season. The contribution of plant food sources to nutrient intakes were over 60% for protein and fat, 50% for calcium, and 70% for iron. Long-lived elderly people an Sung-Ju, Kyungpook showed considerably smaller physiques compared to the avergae Korean elderly, however their average BMI fell in normal range. The subjects were consuming much less energy and nutrients compared to the present Korean RDA for the elderly over age 75. The subject showed relatively good health state in spite of low intakes of energy and nutrients. Therefore it seems to be necessary to establish a set of new RDA for the elderly over age 8.5.

• 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.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11a
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• pp.295-300
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• 1996

To investigate the effects of the side-orifice on the pressure drop for single-phase flow, a series of experiments have been carried out with 16 different downstream test sections with various combinations of side-orifice shapes, different numbers of side-orifices, and different arrangements of the side-orifice using water as a working fluid. From the measurements of the pressure drop and the flow rate, the pressure loss coefficient of the side-orifice(s) has been evaluated. Based on the total number of 529 present data, an empirical correlation for the pressure loss coefficient has been developed in terms of Reynolds number and geometric parameters, such as area ratio, equivalent diameter, leading edge, and average width of side-orifice.

• Structural Engineering and Mechanics
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• v.66 no.4
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• pp.543-555
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• 2018

Fiber Reinforced Polymer (FRP), which has a high strength to weight ratio, are now regularly used for strengthening of deficient reinforced concrete (RC) structures. While various researches have been conducted on FRP strengthening, an area that still requires attention is predicting the debonding failure load of prestressed FRP strengthened RC beams. Application of prestressing increases the capacity and reduces the premature failure of the beams largely, though not entirely. Few analytical methods are available to predict the failure loads under flexure failure. With this paucity, this research proposes a method for predicting debonding failure induced by intermediate crack (IC) for prestressed FRP-strengthened beams. The method consists of a numerical study on beams retrofitted with prestressed FRP in the tension side of the beam. The method applies modified Branson moment-curvature analysis together with the global energy balance approach in combination with fracture mechanics criteria to predict failure load for complicated IC-induced failure. The numerically simulated results were compared with published experimental data and the average of theoretical to experimental debonding failure load is found to be 0.93 with a standard deviation of 0.09.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.663-666
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• 1995

The domain wall motion coercivity, $H_{c}$, of magnetic materials arises from the dependence of the wall energy on localized changes in material parameters (magnetization, anisotropy, exchange energy densities). However, in an otherwise perfectly homogeneous material, the domain wall energy might change due to the change in the volume of the wall versus the wall position. Thus, any surface roughness contributes to the coercivity. Assuming different two-dimensional surface profiles, characterized by average wavelengths ${\lambda}_{x}$ and ${\lambda}_{y}$, and relative thickness variations dh/h, the coercivity due to the surface roughness has been calculated. Compared to the one dimensional case, the 2D coercivity is reduced. Depending on the ratio of ${\lambda}$ to the domain wall width, $H_{c}$ has a maximum around 2, and increasing with dh/h. With the decreasing thickness of the thin film and GMR heads, it might be the domain factor in determining the coercivity.