• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.175-183
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• 2022

With the expansion of the automobile market, the demand for Nd as an essential rare earth material for automobile motors is rapidly increasing. Research on the calcio-thermic reduction process between Nd₂O₃ and calcium-based alloys has been extensively studied in order to manufacture Nd. In this study, Ca-Cu, as a reducing for Nd₂O₃, was prepared by electrolysis in CaCl₂ molten salt. Cu wire and graphite were employed as a working electrode and a counter electrode for electrolysis reaction, respectively. The reference electrode was manufactured by putting Ag wire in a mixture of AgCl and CaCl₂ at a ratio of 1:99 mol%. The cyclic voltammetry results showed that the deposition of Ca²⁺ on the surface of working electrode was observed from a potential of -1.8 V, and the reduction potential of Ca²⁺ decreased as the reaction temperature increased. The diffusion coefficient of Ca²⁺ calculated by the chronoamperometry experiment was found to be 5.4(±6.8)×10^-6 cm²/s. In addition, Ca-Cu liquid alloy was prepared by applying a constant potential to Cu electrodes. The element ratio of Ca-Cu alloy formed by applying a potential of -2.0 V was found to Ca:Cu=1:4.

• Journal of Applied Biological Chemistry
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• v.65 no.3
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• pp.173-181
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• 2022

This study was carried out to investigate the residual characteristics of flubendiamide in kale to establish pre-harvest residue limits (PHRL) and the removal efficiency according to the washing solvent and method. Field tests were conducted at two different greenhouses, field 1 (Anseong-si, Gyeonggi-do) and field 2 (Incheon-si, Gyeonggi-do). According to the safe use guidelines kale was sprayed with flubendiamide twice every 10 days and harvested 0 (after 2 h), 1, 2, 3, 5, 7 and 10 days after the final application. The biological half-live of flubendiamide in kale was calculated based on dissipation curves of the pesticide in samples analyzed by liquid chromatography coupled with tandem mass spectrometry. In the analysis, method limits of quantitation (MLOQ) were 0.01 mg/kg, and recoveries performed with two different fortification levels of 10 MLOQ and maximum residue limit (0.7 mg/kg) were 104.2±3.6 and 101.9±10.2%, respectively. The dissipation rate constant of flubendiamide in kales were 0.2437 at field 1 and 0.1981 at field 2. PHRL calculation equations obtained using the dissipation constants estimated as follows: if the residual concentration of flubendiamide in kale on 10 days before harvest is less than 8.0 mg/kg, the residual concentration on the harvest would be under MRL. The removal of flubendiamide from kale was the greatest when it was washed with vinegar (39.8%), followed by baking soda (31.7%), calcium powder (30.2%), neutral detergent (27.2%), and tap water (15.9%). The results of this study would be useful for both farmers and consumers to produce or consume safe agricultural products.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.2
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• pp.153-160
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• 2023

In this study, nano-sized C-S-H crystals were synthesized using the liquid phase reaction method and their properties were investigated. The synthesized C-S-H crystals were added to the cement composite in suspension form to determine their effect on the hydration properties of the cement. The amount of chemical admixture was varied to obtain nano-sized C-S-H crystals with optimal agglomerated morphology, and SEM photographs were analyzed. A cleaning process was added to remove harmful substances other than the synthesiz ed C-S-H crystals. It was found that the concentration of harmful substances was reduced in the case of C-S-H crystals subjected to the cleaning process. The synthesized C-S-H suspensions were prepared with and without the cleaning process, and cement composites were prepared with the cement weight content as the main variable. The effect of C-S-H crystals on the initial hydration properties of the cement was confirmed by microhydration heat analysis. In addition, mortar specimens were prepared to measure the compressive strength over time. The test results showed that the nano-sized C-S-H crystals act as nucleation sites in the cement paste to promote the early hydration of the cement and increase the early compressive strength.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.11
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• pp.1653-1663
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• 2016

Meat quality is a complex trait influenced by many factors, including genetics, nutrition, feeding environment, animal handling, and their interactions. To elucidate relevant factors affecting pork quality associated with oxidative stress and muscle development, we analyzed protein expression in high quality longissimus dorsi muscles (HQLD) and low quality longissimus dorsi muscles (LQLD) from Duroc pigs by liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomic analysis. Between HQLD (n = 20) and LQLD (n = 20) Duroc pigs, 24 differentially expressed proteins were identified by LC-MS/MS. A total of 10 and 14 proteins were highly expressed in HQLD and LQLD, respectively. The 24 proteins have putative functions in the following seven categories: catalytic activity (31%), ATPase activity (19%), oxidoreductase activity (13%), cytoskeletal protein binding (13%), actin binding (12%), calcium ion binding (6%), and structural constituent of muscle (6%). Silver-stained image analysis revealed significant differential expression of lactate dehydrogenase A (LDHA) between HQLD and LQLD Duroc pigs. LDHA was subjected to in vitro study of myogenesis under oxidative stress conditions and LDH activity assay to verification its role in oxidative stress. No significant difference of mRNA expression level of LDHA was found between normal and oxidative stress condition. However, LDH activity was significantly higher under oxidative stress condition than at normal condition using in vitro model of myogenesis. The highly expressed LDHA was positively correlated with LQLD. Moreover, LDHA activity increased by oxidative stress was reduced by antioxidant resveratrol. This paper emphasizes the importance of differential expression patterns of proteins and their interaction for the development of meat quality traits. Our proteome data provides valuable information on important factors which might aid in the regulation of muscle development and the improvement of meat quality in longissimus dorsi muscles of Duroc pigs under oxidative stress conditions.

• Journal of Wetlands Research
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• v.25 no.1
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• pp.35-47
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• 2023

Korean facility horticulture and hydroponic cultivation methods increase, requiring the management of waste water generated. In this study, the amount of fertilizer contained in the discharged waste liquid was determined. By evaluating this as a price, it was suggested to reduce water treatment costs and recycle fertilizer components. It was evaluated based on the results of major water quality analysis of waste liquid by crop, such as tomatoes, paprika, cucumbers, and strawberries, and in the case of P component, it was analyzed by converting it to the amount of phosphoric acid (P₂O₅). The amount of nitrogen (N) can be calculated by discharging 1,145.90kg·ha^-1 of tomatoes, 920.43kg·ha^-1 of paprika, 804.16kg·ha^-1 of cucumbers, 405.83kg·ha^-1 of strawberries, and the fertilizer content of P₂O₅ is 830.65kg·ha^-1 of paprika, 622.32kg·ha^-1 of tomatoes, 477.67kg·ha^-1 of cucumbers. In addition, trace elements such as potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), and manganese (Mn) were also analyzed to be emitted. The price per kg of each item calculated by averaging the price of fertilizer sold on the market can be evaluated as KRW, N 860.7, P 2,378.2, K 2,121.7, Ca 981.2, Mg 1,036.3, Fe 126,076.9, Mn 62,322.1, Zn 15,825.0, Cu 31,362.0, B 4,238.0, Mo 149,041.7. The annual fertilizer loss amount for each crop was calculated by comprehensively considering the price per kg calculated based on the market price of fertilizer, the concentration of waste by crop analyzed earlier, and the average annual emission of hydroponic cultivation. As a result of the analysis, the average of the four hydroponic crops was 5,475,361.1 won in fertilizer ingredients, with tomatoes valued at 6,995,622.3 won, paprika valued at 7,384,923.8 won, cucumbers valued at 5,091,607.9 won, and strawberries valued at 2,429,290.6 won. It was expected that if hydroponic drainage is managed through self-treatment or threshing before discharge rather than by leaking it into a river and treating it as a pollutant, it can be a valuable reusable fertilizer ingredient along with reducing water treatment costs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1381-1391
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• 2009

Dietary life style of the elderly living in rural areas of Gyeongbuk Andong during the busy farming season was surveyed and a monthly meal plan for the elderly was developed using eco-friendly native crops and considering the characteristics of a busy farming season and their preferences. A week meal plan was selected and applied to those fields. The meal plan was developed for an elder's house in Gyeongbuk Andong during the busy farming season. Especially, to increase the intake of calcium and dietary fiber, bamboo sprouts, pepper leaves, dried slices of whitebait, and fried anchovies were used. Considering the busy farming season, the ginseng chicken soup and the soybean noodle soup were served to provide high quality of protein and to improve health condition. A cold soup of cucumber and brown seaweed was used to supplement liquid, vitamins, and minerals. The results are as follows: the highest score of the preference on a staple was 8.77 for the boiled barley of menu 5; the favorite soup was the ginseng chicken soup (8.73) in menu 4; for side dishes, those in menu 5 were most popular (8.69); the favorite meal was the ginseng chicken soup of menu 4 (8.69). Regarding the amount of leftover foods, the lightest was 30.14 g in Gyeongbuk Andong menu 3 which significantly indicates high preference (p<0.05). The current study was a planned meal service menu using local crops and seasonal foods, which was actually applied to the field resulting in high preference and satisfaction levels.

• Journal of Nutrition and Health
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• v.9 no.4
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• pp.36-46
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• 1976

This study was projected to provide basic data on prenatal care for future direction in maternity and child care, and also to investigate the diet of women during pregnancy and the period directly afterwards in order to offer to mothers appropriate advice for the improvement of nutritional standards. A clinical study on prenatal care was based on 1054 delivery cases. A nutritional survey was performed on 174 mothers admitted to the department of obstetrics at St. Mary's Hospital during the period of March, 1975 to February, 1976. The results obtained are summarized as follows; I. Clinical study on prenatal care 1) The age distribution showed 59.4% of the mothers were between the ages of 25 to 29 years old. 2) The gestational period was highest between the 37th and 40th gestational weeks. 33.7% of the mothers were primigravidae and 31.8% of them primiparae. 3) 41.3% of the mothers had not received prenatal care or had only received it once before. 4) Induced deliveries were 61.8% and spontantaneous deliveries 38.2%. 61.9% of the mothers had received prenatal care, while those without prenatal care accounted for 61.6% of the total induced deliveries. 5) Low birth weights were 7.7% and 5.0% of the mothers had received prenatal care, while 11.5% had no prenatal care. 6) There were 1.13% of still births, 0.32% of the mothers had prenatal care and the remainder did not have prenatal care. 7) Of those receiving prenatal care, 2.1% showed in the $0{\sim}3$ Apgar score group, 6.3% in the $4{\sim}6$ Apgar score group, and 91.6% in the $7{\sim}10$ Apgar score group. Among the non-prenatally cared for group 5.0% of the newborns were in the $0{\sim}3$ Apgar score group, 9.7% were in $4{\sim}6$ Apgar score group and 85.3% were in the $7{\sim}10$ Apgar score group. 8) Obstetrical complications were developed in 11.86% of the pregnant women when they were hospitalized. Among the group receiving the prenatal care 8.1% of the mothers had obstetrical complications. In the group without prenatal care 17.16% of the mothers had obstetrical complications. The most common obstetrical complication was malpresentation. 9) The first prenatal care was received between the 37th and 40th gestationl weeks. II. Food intake during pregnancy The following are the results from the questionnaires of the mothers concerning diets during pregnancy; 1) Main meals and snacks In 32.2% of the cases, their main meals during the diet amounted to more than was usually eaten at other times. In 67.8% of the cases, their main meals during the diet were the same as that usually eaten. In 22.4% of the cases, snacks during the diet amounted to more than usually eaten at other times. In 77.6% of the cases, snacks during the diet were the same as usually eaten. 2) Itemized list The mothers made a special effort to include certain items in their diets, the following is a breakdown of those items; a. egg, meat, fish 33.3% b. fruit, vegetables 32.2%. c. milk, fruit juice 18.4% d. cake, bread 2.9% e. nothing special 13.2% 3) Milk 44.8% of the mothers had at least one cup of milk everyday. 33.4% of the mothers had at least one cup of milk on occasion. 15.5% of the mothers did not have any milk. 4) Vitamins 39.7% of the mothers had vitamins everyday. 24.7% of the mothers had vitamins occasionally. 35.6% of the mothers did not have any vitamins. 5) Anemic symptoms 9.2% of the mothers very often had anemic symptoms during pregnancy. 39.1% of the mothers often had anemic symptoms during pregnancy. 51.7% of the mothers did not have anemic symptoms at all. 6) Taboos on food 23% of the mothers recognized 'taboos' on food during pregnancy 27% of the mothers displayed on uncertainty about the 'taboos' on food during pregnancy 50% of the mothers displayed indifference toward the taboos. III. Nutritional survey on the new mothers diet. 1) The diets for new mothers can be divided into four categories, such as general diet, low sodium diet, soft diet and liquid diet. 2) Cooked rice and seaweed soup were the main foods for the new mothers as has been the traditional diet for Korean mothers. 3) The average diet contained 1,783g. And the average consumption of the basic food groups per capita per day was 1,265g for cereals and grains, 456g for meats and legumes, 58g for fruits and vegetables, 0g for milk and fish and 4g for fats and oils. 4) In addition to the 1,783g of food in the main diet there was also 142.8g of food taken as snacks. 5) The average daily consumption of calories and nutrients was 2,697 Kcal and 123.4g for proteins, 44.9g for fats, 718.2mg for calcium, 14mg for iron, 2,101.4 I.U. for vitamin A, 0.43mg for thiamine, 1.02mg for riboflavin, 15.88mg for niacin, 5.26mg for ascorbic acid. When these figures are compared with the recommended allowances for new mothers in Korea, the calories and nutrients taken in were satisfactory. But the intake of minerals and vitamins was below the recommended allowance.

• Journal of Nutrition and Health
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• v.29 no.8
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• pp.889-898
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• 1996

This study estimated the re!ation between psychological stress and stress hormones, nu­t tritional status of patients with non-insulin dependent diabetes mellitus(NIDDM). Psycho­l logical stress such as depr'ession and anxiety in 34 diabetics was analyzedin relation to nutrient intake, blood components such as fasting blood sugar(FBS), hemoglobin AIC, stress hormones a and amino acids. The IeveIs of depression and anxiety were measured by The center for ep­i idemiological studies-depc$pm$111.49pg/ml for total catecholamine ( (norepmephrine and epinephrine) and 233.95 $pm$73.99pg/ml for norepinephrine, 94.03$pm$75. 9 97pg/ml for epinephrine, 13.lS$pm$5.55pl/dl for cortisol and 171.50$pm$62.50pg/ml for gul c cagon respectlveIy. The leveIs of stress hormones in diabetics such as total catecholamine, norep­i mephrine cortisol and glucagon were significantly higher than those in normal control. The lev­el of epmephrine was higher in diabetics but the diffierenee was not significant. The calorie m t take in diabetics was 1762$pm$292keal which is S1.4% lower than Korean recommended dietary a allowances(RDA). Calcium intake was slightly low but other nutrients intakeswere higher than R RDA. The value of fasting blood sugar(FBS), usual fasting blood sugar(usual FBS) which refteet a average FBS during 3 months and hemoglobin Al C in diabetics was 1S4.1S$pm$74.22mg/dl, 177.76$pm$42.77mg/dl and S.S4$pm$2.S2% respec디VeIy. The distribution of plasma amino acids in d diabetics was generally in the normal range. The leveI of anxiety in diabetics was positively cor­related with norepinephrine, concentration and usual FBS. The levels of glucagon, usual FBS a and hemoglobin Aj C were pOSI디veIy correlated with the branched chaimamino acid(BCM : leucme, isoleucme and valine)

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.2
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• pp.67-73
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• 1979

The effect of liming on the potassium equilibrium activity ratio ($AR^k_e$) of Chinese cabbage cultivated soil and on the potassium uptake by the plant summarize as follows: 1. $AR^k_e$ is raised by the application of 1.6 ton of $Ca(OH)_2$ per hectare that required amount to adjust pH 6 for the soil. Generally, it could be confirmed that both liming and potassium placement to the soil show the combined effects to raise $AR^k_e$. 2. The exchangeable potassium and the electrical conductivity increase by liming. The mean value of the exchangeable potassium is 0.71 m. equ. per 100g of limed soils while the control give 0.64 m. equ. per 100g. For the electrical conductivity, limed soil show $766{\mu}mho$ and $750{\mu}mho$ is for the control. 3. The reason $AR^k_e$ value increase by liming could be considered that concentrations of $K^+$ and $Ca^{{+}{+}}+Mg^{{+}{+}}$ in the equilibrium solution are increased owing to release both K and $Ca^+$ Mg into the liquid from solid phase in the potassium equilibrium system of the soil. 4. For considering that the energies of exchange of calcium by potassium in the limed soils at different potassium treatment, that is without K, 200 kg $K_2O/ha$ and 350 kg $K_2O/ha$, give -3887 and -3778 and -3737 calories per chemical equivalent respectively. On the other hand in case of the controls which received the same amounts of potassium as mentioned above, energy values are -3983, -4392 and -4228 calories respectively. 5. The absorbed amount of potassium and weights of dry matters of the plant which grown in the limed soils show little higher values than the controls.