• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.312-313
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• 2015

무전해 도금은 석출응력이 낮고 작업하기가 용이하기 때문에 산업분야에 있어서 중요한 역할을 한다. 무전해 도금 공정에 있어서, 니켈금속은 차아인산염, 아미노보레인 혹은 수소화붕소 화합물($HBF_4$)에 의한 니켈이온의 화학적 환원에 의해 도금된다. 환원반응이 진행함에 따라서 도금액 중에서 니켈과 차아인산염 이온은 감소한다. 이에 이러한 이온을 보충하기 위하여 도금액 중에 황산니켈과 차아인산나트륨이 일반적으로 첨가된다. 하지만 축적된 인산염, 황산염, 나트륨과 이외의 물질이 전착 박막의 품질을 떨어뜨리고 도금액은 폐기되기도 한다. 니켈회수 속도는 종래의 50% 이하였던 것이 90%이상으로 향상되었다. 이온교환법은 니켈도금 폐액으로부터 니켈회수에 필요한 친환경적이고 원가절감의 기술이라고 사료된다. 특히, 갈탄이 저렴하고 양이온 교환성능이 뛰어나다. 이유는 -COOH, -OH 등의 기능성 그룹을 갖기 때문이다. Fe-P 화합물은 식물에 유용하지 못하고 마그네슘과 칼슘 기반의 석출물은 저렴하고 취급이 용이하며 비료와 같이 재활용이 가능하기 때문에 일반적인 인의 제거 수단이 될 수 있다. 본고에서는 니켈도금 폐액으로부터 인을 제거하는 데 $Ca(OH)_2$, $CaCl_2$와 $CaCO_3$를 채택하여 인이 제거되는 정도를 비교하였고 니켈회수율을 높이기 위하여 갈탄을 사용하였다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.391-418
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• 1983

Urea and ammonium sulfate without and with sulfur group, respectively, were compared with respect to their nutritive effects on the rice plants, Suweon 264 and Jinheung, under the nursery trial on the protected upland and lowland seedbed, the pot trials with their various combination ratios and with added sodium sulfate to urea and the trials on the paddy fields which have undergone urea and ammonium sulfate application for many years. The rice seedlings fertilized with ammonium sulfate surpassed those with urea in growth performance and nutrients absorption of the rice seedlings at nursery period. Such stimulating effect of ammonium sulfate on the growth and nutrients uptake was more remarkable under the upland nursery than under the lowland one. The pot trial with the various combination ratios of urea and ammonium sulfate revealed that the chlorophyll content in leaf blade increased with the increment of sulfate ratio in the combination and the sole application of urea caused the chlorosis of leaf which was more conspicuous in Suweon 264 than in Jinheung. Fertilized with the same active ingradient amount of nitrogen, the rice plants supplied with ammonium sulfate surpassed those with urea in the chlorophyll content consistently under the nursery, the pot and the paddy field trials. The photosynthesis of flag leaf at heading stage increased with the combination rate of ammonium sulfate in the pot trial. The sulfur applicated as supplementary element of nitrogen in the nursery, the pot and the field trials were observed to be in positive relationship to the nitrogen and potassium content, but to be in negative correlation to the calcium content. The sulfur content in the rice plants was higher at early growth stage and decreased with the advance in growth stage. The nitrogen content also showed a similiar tendency to the sulfur content, and the N/S ratio was higher at early growth stage than at later one. The N/S ratio was negatively correlated with the chlorophyll content. In the field experiment, ammonium sulfate surpassed urea in the number of productive tiller, dry matter production and unhulled rice yields, but much stimulating effect of ammonium sulfate on the grain production was shown to be less effective than that on the straw production. The nitrogen and major nutrients content in the rice straw at harvest were higher in the paddy field with long-term ammonium sulfate application than in that with long-term urea application, suggesting that the former might have greater potentiality in nutrients supply than the latter.

• Childhood Kidney Diseases
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• v.11 no.1
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• pp.9-15
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• 2007

Purpose : Edema is one of the cardinal features of nephrotic syndrome. Although the pathogenesis of edema is not entirely understood, it is caused by hypovolemia or hypervolemia by different mechanisms. Accordingly it is important to evaluate the volume status of patients in order to treat the edema, but it is difficult to evaluate the patient's volume status only by clinical parameters. The quotient of urine sodium and potassium excretion $U_K/(U_{Na}+U_K)$ is introduced as a more useful way to evaluate volume status. In this study we will propose the usefulness of $U_K/(U_{Na}+U_K)$ in evaluating the volume status of children with nephrotic syndrome. Methods : Primary nephrotic syndrome patients at Yeungnam University Hospital since January 1995 to June 2005, were included in the study. We analyzed clinical parameters such as tachycardia, cardiomegaly, pleural effusion, blood chemistry and urinalysis prospectively. We defined hypovolemia when $U_K/(U_{Na}+U_K)$ exceeded 60%. Intravenous albumin and diuretics were administered to hypovolemic edematous patients. On the other hand, hypervolemic edematous patients were treated only with diuretics. Results : There were 50 cases of primary nephrotic syndrome patients(hypervolemia: 29 vs hypovolemia: 21). There were no significant differences in clinical symptoms and laboratory findings except for FeNa While $F_eNa$ and $U_K/(U_{Na}+U_K)$ had a significant negative correlation, BUN and $U_K/(U_{Na}+U_K)$ had a significant positive correlation. Urine output after edema treatment was effective and there were no treatment-related side effects in both groups. Conclusion : FeNa, BUN and $U_K/(U_{Na}+U_K)$ are a useful parameters for evaluating volume status of edematous nephrotic syndrome patients. We could suggest a therapeutic option for using albumin and/or diuretics according to volemic status by means of measured $U_K/(U_{Na}+UK)$.

• Journal of Nutrition and Health
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• v.52 no.4
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• pp.342-353
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• 2019

Purpose: The Dietary Reference Intakes for Koreans (KDRIs) suggest that the goal for the intake of sodium should be less than 2,000 mg, which is thought to be infeasible to achieve when eating the typical Korean diet. This study aimed to obtain the new intake goals for sodium with improved feasibility to achieve, and also to design optimized food intake patterns for Korean adults by performing linear programming. Methods: The data from a one day 24-hour dietary recall of the 2010 ~ 2014 Korea National Health and Nutrition Survey were used to quantify food items that Korean adults usually consumed. These food items were categorized into seven groups and 24 subgroups. The mean intakes and intake distributions of the food groups and the food subgroups were calculated for eight age (19 ~ 29, 30 ~ 49, 50 ~ 64, and over 65 years old) and gender (male and female) groups. A linear programming model was constructed to minimize the difference between the optimized intakes and the mean intakes of the food subgroups while meeting KDRIs for energy and 13 nutrients, and not exceeding the typical quantities of each of the food subgroups consumed by the respective age and gender groups. As an initial solution of the linear programming, the optimized intake of seasonings, including salt, was calculated as 0 g for all the age and gender groups when the sodium constraint was inserted not to exceed 2,000 mg. Therefore, the sodium constraint was progressively increased by 100 mg until the optimized intake of seasoning was obtained as the values closest to the $25^{th}$ percentile of the intake distribution of seasonings for the respective age and gender groups. Results: The optimized food intake patterns were mathematically obtained by performing linear programming when the sodium constraint values were 3,600 mg, 4,500 mg, 4,200 mg, 3,400 mg, 2,800 mg, 3,100 mg, 3,100 mg, and 2,500 mg for the eight age and gender groups. Conclusion: The optimized food intake patterns for Korean adults were designed by performing linear programming after increasing the sodium constraint values from 2,000 mg to 2500 ~ 4,500 mg according to the age and gender groups. The resulting patterns suggest that current diets should be modified to increase the intake of vegetables for all the groups, milk/dairy products for the female groups, and fruits for the female groups except for the females aged 50 ~ 64 years.

• Resources Recycling
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• v.32 no.1
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• pp.21-32
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• 2023

Because the application of lithium has gradually increased for the production of lithium ion batteries (LIBs), more research studies about recycling using solvent extraction (SX) should focus on Li⁺ recovery from the waste solution obtained after the removal of the valuable metals nickel, cobalt and manganese (NCM). The raffinate obtained after the removal of NCM metal contains lithium ions and other impurities such as Na ions. In this study, we optimized a selective SX system using di-(2-ethylhexyl) phosphoric acid (D2EHPA) as the extractant and tri-n-butyl phosphate (TBP) as a modifier in kerosene for the recovery of lithium from a waste solution containing lithium and a high concentration of sodium (Li⁺ = 0.5 ~ 1 wt%, Na⁺ = 3 ~6.5 wt%). The extraction of lithium was tested in different solvent compositions and the most effective extraction occurred in the solution composed of 20% D2EHPA + 20% TBP + and 60% kerosene. In this SX system with added NaOH for saponification, more than 95% lithium was selectively extracted in four extraction steps using an organic to aqueous ratio of 5:1 and an equilibrium pH of 4 ~ 4.5. Additionally, most of the Na⁺ (92% by weight) remained in the raffinate. The extracted lithium is stripped using 8 wt% HCl to yield pure lithium chloride with negligible Na content. The lithium chloride is subsequently treated with high purity ammonium bicarbonate to afford lithium carbonate powder. Finally the lithium carbonate is washed with an adequate amount of water to remove trace amounts of sodium resulting in highly pure lithium carbonate powder (purity > 99.2%).

• Journal of Food Hygiene and Safety
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• v.24 no.4
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• pp.332-337
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• 2009

Most propionic acid is added to food (especially breads) as preservatives and its form is sodium or calcium salt. Most countries admitted propionic acid as food preservatives but a tolerance limit is somewhat different according to countries. Recoveries of the official method for propionates reported as 50.0~60.0%. Accordingly new rapid determination method for propionates was developed using formic acid added sodium chloride (5 g) and ether (formic acid : ether = 1 : 2) as the extraction solvent to improve the official method with the complex processes. Propionate was dissolved from the samples with formic acid omitting steam distillation and ion exchange procedure. Then propionate in formic acid was extracted with ether and sodium chloride again. A $1\;{\mu}l$ aliquot of the filtrate of ether was analyzed by gas chromatograph. Recoveries from sample A and B fortified with propionic acid sodium salt were 85.0 % and 90.0 %, respectively.

• Korean Chemical Engineering Research
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• v.51 no.5
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• pp.561-567
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• 2013

Mixed hardwood chips were pre-pulping extracted with green liquor prior to kraft pulping in order to recover hemicelluloses for use as biofuels. This green liquor solution containing mainly sodium sulfide and sodium carbonate was applied at different alkali charges (expressed as $Na_2O$) of 0, 1, 3, and 5% on dry wood weight. The extractions were performed at $160^{\circ}C$ for residence times ranging from about 1-2 h to determine the effect of extraction severity on composition of the pre-pulping extract. The severity of hemicellulose extraction time and green liquor charge controls the concentration of acetic acid and monosaccharide sugars available for downstream processing, the accumulation of degradation products such as organic acids and furans in the extract. As the alkali charge was increased, the amount of acetate side chains on the hemicelluloses and the dissolved lignin in the extract increased but the carbohydrate and sugars in the extract decreased appreciably. Hot water extraction (0% alkali addition) released the greatest amount of carbohydrates, up to 29.80 g/L measured as component sugars, but resulted in the greatest decrease in pulp yield. Meanwhile, pre-pulping extraction with 3% green liquor increased the pulp yield while greatly reducing the component sugars to 7.08 g/L. Fundamental data obtained in this study will allow selection of optimum hemicellulose extraction conditions for integrating the extraction operation into the Kraft pulping process.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.713-716
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• 2005

Nutritional constituents of native Yangha (zingiber mioga) in Yeosu and Cheju areas were examined. Average water, crude protein, crude lipid, carbohydrate, ash, and fiber contents of Yangha were 94.85, 0.62, 0.24, 3.30, 0.92, and 0.74%, respectively. Proximate composition of Yangha was significantly different between two areas except moisture and ash content. Average calcium, magnesium, sodium, potassium, iron, copper, and manganese contents were 40.57, 55.60, 26.14, 598.58, 4.14, 0,26, and 0.26 mg/100g, respectively. Magnesium, sodium, and iron contents of CY were significantly higher than those of YY. Total amino acid contents of Yangha was 645.19mg/100g. Amino acid of Yangha showed high content of glutamic acid, followed by aspartic acid and valine.

• Korean Journal of Organic Agriculture
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• v.20 no.2
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• pp.231-241
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• 2012

Farming using natural salts for supply of nutrients to crops is increasing recently. It is necessary to evaluate the salt accumulation in soil and the effects on crop growth by treatment of natural salt. This study was conducted at the organic cultivation fields which garlics were planted. The treatments were no natural salts (control) and plots applied 100~600 $kg\;ha^{-1}$ with natural salts. Soil samples were taken from the 0 to 25 cm depth at 12 and 107 day (harvest time) after natural salts application. The results showed that electrical conductivity (EC), exchangeable Na (Exch.$-Na^+$) and Cl- were increased by application of natural salts. But, pH and exchangeable cations ($K^+$, $Ca^{2+}$ and $Mg^{2+}$) had not significantly differences among treatments. In 300 $kg\;ha^{-1}$ plots of natural salt, the level of EC, Exch.$-Na^+$ and $Cl^-$ in top soil (0-5 cm) was were increased more 0.3, 3.7, and 12.7 times than control plot, respectively. EC, Exch.$-Na^+$, and $Cl^-$ were highest in the top 5 cm of soil and decreased with depth at 12 days after natural salts application, but were decreased in the plower layer (0-15cm) at the harvest time because they were leached with natural rain. An increasing the application level of natural salt resulted in increasing of sodium adsorption ratio, exchangeable sodium percentage, and percentage of soil dispersion. The concentration of nutrient uptake such as total nitrogen (T-N), chloride (Cl) in garlic had significant difference between control and plots applied with natural salts The content of T-N of garlic in plots with natural salt application was lower than control plot, but Cl is higher than control plot.

• Korean Journal of Community Nutrition
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• v.26 no.4
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• pp.270-279
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• 2021

Objectives: The purpose of this study was to evaluate the effect of the sodium and sugar reduction practices of the Samsam foodservice project of Daegu, in comparison with that of general foodservices in Daegu. Methods: A survey was conducted on 80 Samsam foodservice workers and 80 general foodservice workers from Sep. to Oct. 2020. We compared each worker's taste preferences, stage of behavior change and dietary behavior regarding sodium and sugar, and each foodservice's practices regarding sodium and sugar reduction. Results: There was no significant difference between the salty taste and sweet taste preferences between the workers at the Samsam foodservices and those at the general foodservices. The percentage of foodservice workers in action or maintenance stage of behavior change for eating less salty was higher in the Samsam foodservices than in the general foodservices (P < 0.05). In addition, regarding the degree of saltiness and sweetness of meals, the workers at the general foodservices perceived their meals to be saltier (P < 0.001) and sweeter (P < 0.01) than the workers at Samsam foodservices. The workers at Samsam foodservices had fewer salty dietary behaviors compared to the workers at general foodservices (P < 0.01). The sodium reduction practice was significantly higher in the Samsam foodservices than the general foodservices (P < 0.001), especially in "efforts to make the food as bland as possible overall" (P < 0.001), and "serving less soup and stew" (P < 0.001). The sugar reduction practice too was significantly higher in the Samsam foodservices than the general foodservices (P < 0.001). Conclusions: The Samsam foodservices were shown to be better in the practice of sodium and sugar reduction compared to general foodservices. Therefore, it is necessary to provide continuous and practical support and incentives at the national level to expand the sodium and sugar reduction practices in foodservices.