• E2M - 전기 전자와 첨단 소재
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• 제8권6호
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• pp.744-751
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• 1995

This paper describes a study on absorption properties of electromagnetic wave by the composition ratio of Ni-Zn ferrite. Ni-Zn ferrite was composed of 48-52mol% Fe$\_$2/O$\_$3/, 18-22mol% NiO and 26-34mol% ZnO. The sintering of the composition was carried out at 1200.deg. C for 2 hours. Through the experiments, it was found that the resonance phenomenon occured at low frequency range for high permeability and vice versa. In the case of the composition of 49mol% Fe$\_$2/O$\_$3/, 20mol% NiO and 31mol% ZnO, the bandwidth ranged from 0.35GHz to 0.95GHz with the absorption thickness of 10mm. Also, in the case of the composition 51mol% Fe$\_$2/O$\_$3/, 22mol% NiO and 27mol% ZnO, the bandwidth ranged from 0.48GHz to 1.2GHz with the absorption thickness of 6mm.

• Macromolecular Research
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• 제16권3호
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• pp.231-237
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• 2008

Biodegradable poly($\varepsilon$-caprolactone-co-L-lactide)-b-poly(ethylene glycol) (PCLA-b-PEG) copolymers were synthesized via solution polymerization by varying the feed composition of $\varepsilon$-caprolactone ($\varepsilon$-CL) and L-lactide (LLA) ($\varepsilon$-CL: LLA= 10:0, 7:3, 5:5, 3:7, 0: 10). The feed ratio based on weight is in accordance with the copolymer composition except for the case of $\varepsilon$-CL: LLA=3:7 (C3L7), which was verified by $^1H$-NMR. Two different approaches were used for the exceptional case, which is an extension of the reaction time or the sequential introduction of the monomer. A copolymer composition of $\varepsilon$-CL: LLA=3:7 could be obtained in either case. The chemical microstructure of PCLA-b-PEG was determined using the $^{13}C$-NMR spectra and the effect of the sequential structure on the thermal properties and crystallinity were examined. Despite the same composition ratio of the copolymer, the microstructure can differ according to the reaction conditions.

• 한국환경과학회지
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• 제30권7호
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• pp.537-545
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• 2021

This study aimed to investigate the improvement effect of 5% (w/w) mung bean (Phaseolus aureus L.) on lipid composition and protein concentration in hyperlipidemic rats. Seven-week-old male (Sprague-Dawley) rats were divided into four groups (n=6, each), and fed experimental diets containing mung bean meal [basal diet+5% (w/w) mung bean (BM), basal-hyperlipidemic diet+5% (w/w) mung bean (BHM)], basal-hyperlipidemic diet (BH), and control (basal diet, BD). Lipid composition in the mung bean diet groups (BM and BHM) evidenced significant reductions in serum total cholesterol, low-density lipoprotein cholesterol, atherosclerotic index, cardiac risk factor, triglyceride, phospholipid, free cholesterol, cholesteryl ester, blood glucose, nonesterified fatty acid, and an elevation in high-density lipoprotein cholesterol. The serum albumin/globulin ratio was increased in mung bean diet-supplemented rats compared to that in hyperlipidemic rats (p < 0.05). Total calcium, phosphorus and potassium concentrations in sera were higher in the BM, BHM and BD groups than in the BH group. Concentrations of sodium and chlorine in sera were lower in the mung bean diet-supplemented groups than in the hyperlipidemic group. The in vivo experiments showed that ingestion of mung bean was effective in improving lipid composition, protein concentration, and blood glucose.

• The Journal of Asian Finance, Economics and Business
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• 제10권2호
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• pp.163-174
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• 2023

This study aims to investigate the effect of the composition of the board and ownership structure on a firm's value in Jordanian firms. Specifically, it aims to determine the effect of board size, (CEO) duality, and family, foreign, institutional, and government ownership on a firm's value. An ordinary least square regression (OLS) was employed to examine the study hypotheses in a sample of 35 Jordanian industrial firms (175 firm-year observation) for a period of five years from 2016-2020. As measured by Tobin's Q (Q ratio) and market-to-book (MB ratio) for Jordanian industrial firms listed on Amman Stock Exchange (ASE). The result found that foreign ownership, institutional ownership, and family ownership have a significant and positive effect on firm value. By contrast, government ownership does not have a significant effect on firm value. With respect to board composition (CEO duality and board size), the study results found no evidence to support the effect of board composition on firm value. The study recommended the concerned authorities with several recommendations, most notably: taking the necessary measures to ensure the continuity and growth of family businesses because of their positive impact on the value of the company and economic growth, spreading awareness about how governance protects the interests of investors.

• 한국전기전자재료학회논문지
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• 제12권1호
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• pp.94-102
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• 1999

Ni/CGO cermets were fabricated as the anode for SOFC which uses CGO as the electrolyte. And their electrical conductivity, electrochemical reactivity, and thermal expansion coefficient were optimized through the variation of NiO/CGO particle size ration and their composition. The electrical conductivity of the cermet was increased abruptly at a certain Ni content and the percolation concentration was decreased with the decreasing particle size ratio. Anodic overpotential was also decreased with the decreasing particle size ratio. For a fixed ratio it showed a minimum value at 50 wt.%. Thermal expansion coefficient was increased monotonically with increasing Ni contents, however it did not depend on the size ratio. With three properties taken into account, the cermet of particle size ration of 0.03 and composition of 50 wt.% was judged to be optimal as the anode.

• Corrosion Science and Technology
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• 제21권5호
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• pp.360-371
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• 2022

Electropolishing has various parameters because an electrochemical reaction is applied. Accordingly, experiments to determine factors and levels of electropolishing conditions are in progress for various materials. The purpose of this investigation was to optimize conditions for electropolishing using the taguchi method for UNS S31603. Factors such as electrolyte composition ratio, electrolyte temperature, and electropolishing process time were selected. Electropolishing was optimized using analysis of variance (ANOVA), signal-to-noise ratio (the smaller the better characteristics), and surface analysis. Results of ANOVA revealed that only the electrolyte composition ratio among factors was effective for surface roughness. As a result of statistical analysis of the signal-to-noise ratio, the highest signal-to-noise ratio was calculated under electropolishing conditions with sulfuric acid and phosphoric acid ratio of 4:6, an electrolyte temperature of 75 ℃, and electropolishing process time of 7 minutes. In addition, the surface roughness after electropolishing under the above conditions was 0.121 ㎛, which was improved by more than 88% compared to mechanical polishing.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2000년도 춘계총회 및 학술발표회
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• pp.34-34
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• 2000

• Journal of Nutrition and Health
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• 제34권7호
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• pp.778-785
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• 2001

In Korea, the concerns about the consumption of soy-based infant formulas have received considerable public attention. In has been known that the n-3/n-6 ratio of soy has a beneficial effect on the health. This study was conducted to investigate whether the soy-based infant formula has an effect on the composition of fatty acids in erythrocytes with regard to the plasma lipid levels in full-term infants. The infants who were delivered at Kyung Hee Medical Center were recruited. Experimental groups were the breast milk group(n=17), soy-based infant formula group(n=12) and casein-based infant formula group(n=19). Anthrophometic and dietary assessments were performed and the composition of RBC fatty acids and blood lipid levels were measured. The body weight, length, chest circumference and head circumference of the subjects were normal growth range showing no significant difference among the experimental groups. The ratio of n-3/n-6 ratio in breast milk, soy-based infant formula and casein-based infant formula were 0.11, 0.14 and 0.13, respectively. N-3/n-6 ratio of the subjects erythrocyte fatty acids for each groups were 0.18, 0.21 and 0.17, respectively. Most of the fatty acids of erythrocyte were not significantly different among the three experimental groups. The blood lipid levels of each experimental group were normal range. The total lipid level of casein-based formula group was higher than that of other experimental groups and LDL-cholesterol level of soy-based formula group was the lowest among the three groups.

• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1190-1197
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• 2016

The acid response of Bifidobacterium longum subsp. longum BBMN68 has been studied in our previous study. The fab gene, which is supposed to be involved in membrane fatty acid biosynthesis, was demonstrated to be induced in acid response. In order to investigate the relationship between acid response and cell membrane fatty acid composition, the acid adaptation of BBMN68 was assessed and the membrane fatty acid composition at different adaptation conditions was identified. Indeed, the fatty acid composition was influenced by acid adaptation. Our results showed that the effective acid adaptations were accompanied with decrease in the unsaturated to saturated fatty acids ratio (UFA/SFA) and increase in cyclopropane fatty acid (CFA) content, which corresponded to previous studies. Moreover, both effective and non-effective acid adaptation conditions resulted in decrease in the C_18:1 cis-9/C_18:1 trans-9 ratio, indicating that the C_18:1 cis-9/C_18:1 trans-9 ratio is associated with acid tolerance response but not with acid adaptation response. Taken together, this study indicated that the UFA/SFA and CFA content of BBMN68 were involved in acid adaptation and the C_18:1 cis-9/C_18:1 trans-9 ratio was involved in acid tolerance response.

• 대한지역사회영양학회지
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• 제16권4호
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• pp.454-465
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• 2011

This study was carried out to investigate distribution of obesity, body composition, weight control and dietary behaviors, and to analyze the relationship between Body Mass Index (BMI) and physical characteristics, body composition and dietary behaviors by anthropmetric measurement and questionnaires. The 199 study subjects were divided into 3 age groups; 30's (78), 40's (77) and 50's (44) and 4 groups by BMI ; under weight (4.5%), normal (51.3%), over weight (26.1%) and obese (18.1%). Amount of skeletal muscle, body water, mineral and body fat were significantly increased with BMI. There were especially significant increase skeletal muscle 5.3 kg ($19.1\;{\rightarrow}\;23.5\;kg$), body water 5.3 kg ($26.3\;{\rightarrow}\;31.6\;kg$) and fat 15.2 kg ($11.2\;{\rightarrow}\;26.4\;kg$) from under weight to obesity group, respectively (p < 0.01). There were significantly decreased in the ratio of body water (10.3%), protein (2.7%) and body mineral (1.1%) from under weight to obesity, but significant increase 14.1% in body fat (p < 0.001). About 44.4% of under weight group and 40.1% of normal group and 50% of over and obesity group had dissatisfaction on their body images. Most of the women were concerned about their body images and experienced weight control. Dietary behavior scores of obesity group were significant lower than the other four groups (p < 0.001). There were significant positive correlation between BMI and body water (r = 0.62), protein (r = 0.52), skeletal muscle (r = 0.63), body fat (r = 0.91) and WH ratio (r = 0.91), respectively (p < 0.001). The correlation between BMI and body fat and WH ratio were much higher than the correlation between weight and fat and WH ratio.