• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.99-105
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• 2000

The purpose of this study was to evaluat the Zn, Cu, Mn and Ni status and correlation of their concentrations in serum, urine, hair and fingernail in female college students. As the results are follows; The mean age of subjects was 22.5 years and height, weight and BMI were 160.1 cm, 51.0 kg and 20.0 respectively. The daily intake of energy 1769.5 kcal and the ratio of carbohydrate, fat and protein for energy is 60 : 20 : 15. The daily intake of energy (88.5%), vitamin B2 (86.1%), Ca (75.4%), Fe (58.3%) and Zn (63.0%) of subjects did not reach to Korean Recommended Dietary Allowance (RDA). The daily mean intake of Zn, Cu, Mn and Ni were 7.56 mg, 2.30 mg, 3.81 mg and 0.18 mg respectively. The concentrations of Zn in serum, urine, hair and nail were 85.6$\mu\textrm{g}$/dL, 391.2$\mu\textrm{g}$/day, 174.6$\mu\textrm{g}$/g and 102.4$\mu\textrm{g}$/g respectively and those Cu were 84.2$\mu\textrm{g}$/dL, 56.6 $\mu\textrm{g}$/day, 20.3$\mu\textrm{g}$/g and 4.3$\mu\textrm{g}$/g respectively. The concentrations of Mn in serum, urine, hari and nail were 0.2$\mu\textrm{g}$/dL, 1.1$\mu\textrm{g}$/day, 1.8$\mu\textrm{g}$/g and 1.6$\mu\textrm{g}$/g respectively and those of Ni were 0.6$\mu\textrm{g}$/dL, 24.5$\mu\textrm{g}$/day, 3.5$\mu\textrm{g}$/g and 3.1$\mu\textrm{g}$/g respectively. The daily intake of Mn showed the positive correlations with concentration of Mn in hair (p<0.05) and the daily intake of Ni was positively correlated with urinary exretion (p<0.05) and hair contents (p<0.001) of Ni. The more detailed studies about these trace mineral status should be required.

• Journal of The Korean Astronomical Society
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• v.56 no.1
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• pp.11-22
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• 2023

We report the result of a high-resolution spectroscopic study on seven magnesium (Mg) enhanced stars. The high Mg abundances in these stars imply that they were born in an environment heavily affected by the nucleosynthesis products of massive stars. We measure abundances of 16 elements including Mg and they show various abundance patterns implying their diverse origin. Three of our program stars show a very high Mg to Si ratio ([Mg/Si] ≈ 0.18-0.25), which might be well explained by fall-back supernovae or by supernovae with rapid rotating progenitors having an initial mass higher than about 20 M_⊙. Another three of our program stars have high light to heavy s-process element ratios ([Y/Ba] ≈ 0.30-0.44), which are consistent with the theoretical prediction of the nucleosynthesis in rapidly rotating massive stars with an initial mass of about M = 40 M_⊙. We also report a star having both high Y ([Y/Fe] = 0.2) and Ba ([Ba/Fe] = 0.28) abundance ratios, and it also shows the highest Zn abundance ratio ([Zn/Fe] = 0.27) among our sample, implying the nucleosynthesis by asymmetric supernova explosion induced by very rapid rotation of a massive progenitor having an initial mass between 20 M_⊙ ≲ M ≲ 40 M_⊙. A relative deficiency of odd-number elements, which would be a signature of the pair-instability nucleosynthesis, is not found in our sample.

• Journal of Korea Soil Environment Society
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• v.2 no.2
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• pp.53-60
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• 1997

A series of batch and lab-scale pilot tests were conducted to optimize the design parameters for the application of soil washing techniques to the soil contaminated by heavy metals. Cu, Pb, and Zn were selected as target heavy metals. The concentrations of Cu, Pb, and Zn were 500mg/kg dry soil, 1, 000mg/kg dry soil, and 500mg/kg dry soil, respectively. Citric acid and oxalic acid were used for the extractants. In the batch tests, the extraction efficiencies for Cu, Pb, and Zn were 79%, 72%, 72%, respectively. The proper extractant concentration and dilution ratio(weight/volume) for Cu and Pb were turned to be citric acid 50mM and 1:5, respectively. The extraction efficiencies were enhanced with the addition of 1~2% OA-5 or SDS. From pilot scale tests for Pb, first stage and second stage of soil washing resulted in the extraction efficiency of 59% and 78%, respectively.

• Food Science and Preservation
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• v.18 no.4
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• pp.575-583
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• 2011

This study was conducted to investigate the major chemical components of dried baked garlic powder. The proximate compositions of baked garlic powder as a dry-matter basis were 5.30% moisture, 36.89% crude protein, 12.60% crude fat, 4.36% crude ash, 2.88% dietary tiber, and 37.97% carbohydrate, respectively. The major free sugars were identified as fructose and galactose. In the analysis of the total amino acids, 18 kinds of components were isolated from baked garlic powder. The essential amino acid contained in baked garlic powder accounted for 36.60% of total amino acids, while the non-essential amino acids accounted for 63.40%. The major unsaturated fatty acids of total lipids were linoleic acid. The ratio of polyunsaturated fatty acids to saturated fatty acids (P/S ratio) was 5.77. Oxalic acid was the major organic acids. The contents of vitamin A, C, and E were 0.064, 1.452, and 0.037 mg%, respectively. The mineral contents of baked garlic powder were greater, in order of K>Mg>Ca>Na>Zn>Fe. The total polyphenol, flavonoids and thiosulfates contents of baked-garlic ethanol extract were $2.85{\pm}0.05$ mg/100 g, $0.97{\pm}0.04$ mg/100 g and $0.61{\pm}0.02$ OD/g, respectively.

• Horticultural Science & Technology
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• v.18 no.3
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• pp.399-403
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• 2000

Recently, abnormal leaf chlorosis has been observed in jujube trees of the major production area in Kyongbuk province. To determine possible causes for the observation, physico-chemical properties of the orchard soil and nutrient contents in the jujube trees were investigated. The chlorosis symptoms were categorized into three types based on the site of chlorosis initiation; leaf center, petiole, and intravein. Of the three, leaf center chlorosis was the most common. The symptom occurred more frequently in Ihyeon, Gyuam, and Geugrag soil series with previous history of apple orchard. In general, the soil and the tree showing leaf chlorosis had lesser nutrient contents than normal except P, Fe, and Zn. In particular, Mg contents in leaf, branchlet, and fruit of the tree were as much as 4 times lesser than those in normal tree; the soil also had 7.8 times lesser Mg contents. The results indicate that the abnormal leaf chlorosis in jujube tree may be caused by nutrient deficiency in soil and could be cured by proper fertilization.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.4
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• pp.375-381
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• 2011

The primary aim of this study is to investigate the probabilistic characteristics of the fatigue parameters that describe the fatigue crack growth behavior in magnesium alloy. Statistical fatigue crack propagation experiments have been performed on rolled AZ31 magnesium alloy CT specimens with different specimen thickness, load ratio, and maximum load at ambient temperature in a laboratory. Using the statistical fatigue data obtained from these experiments, the goodness-of-fit of the probability distribution of the fatigue behavior parameters is evaluated in this study by performing statistical analyses. The crack growth rate coefficient is a fatigue parameter having a very large COV(Coefficient of Variation), but the variation of a crack growth rate exponent is not substantial. It is considered that a crack growth rate exponent can be a material constant. It is also found that the best fit probability distribution of the parameters such as the crack growth rate coefficient and crack growth rate exponent for a magnesium alloy is a three-parameter Weibull distribution, and two-parameter Weibull distribution is a good distribution only for the crack growth rate coefficient.

• Korean Journal of Community Nutrition
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• v.2 no.4
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• pp.515-522
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• 1997

This study was done to compare serum levels of lipids, trace minerals, ceruloplasmin and ferroxidase activity between female college smokers and nonsmokers. Serum levels of lipids, Cu, Zn, ceruloplasmin and ferroxidase activity were determined in 33 smokers and 42 nonsmokers residing in the Seoul area. Serum levels of TG, total cholesterol and HDl-cholesterol were measured using test kits. Serum Cu Zn were determined by the AAS. Serum ceruloplasimin level and ferroxidase activity were determined by spectrophotometric methods. All data were statistically analyzed by the SAS PC package program. Mean and standard errors were calculated for each item, and the significance of the difference between two groups was evaluated by Student's t-test at p〈0.05. There was no significant difference in levels of total cholesterol, TG, VLDL-cholesterol, LDL-cholesterol, LDL/HDL and atherogenic index, but HDL-cholesterol level was significantly lower(p$\ll$0.05) in female college smokers than in nonsmokers. Serum zinc level showed no significant difference, whereas copper level was significantly higher in smokers, consequently yielding higher Cu/Zn ratio in smoking college women. Ceruloplasmin level was 32.6mg/dl in smoking college women, which was significantly higher(p$\ll$0.05) than that of 28.6mg/dl in nonsmokers. However, cerulopasmin ferroxidase activity, 0.34U/mg in nonsmokers was higher(p$\ll$0.05) than that of 0.29U/mg in smokers. From these results, it is confirmed that cigarette smoking itself has a very detrimental effect on health and mineral nutritional status although the smoking history is relatively short among college women(pack-years=1.7). (Korean J Community Nutrition 2(4) : 515-522, 1997)

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.62-62
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• 2013

Magnesium alloys exhibit many attractive properties such as low density, high strength/weight ratio, high thermal conductivity, very good electromagnetic features and good recyclability. However, most commercial magnesium alloys require protective coatings because of their poor corrosion resistance. Attempts have been made to improve the corrosion resistance of the Mg alloys by surface treatments, such as chemical conversion coatings, anodizing, plating and metal coatings. Among them, chemical conversion coatings are regarded as one of the most effective and cheapest ways to prevent corrosion of Mg alloys. In this study, the effects of various $Zn^{2+}$ concentrations and pH levels on the formation of zinc phosphate conversion coatings (ZPCCs) on AZ31 magnesium alloy were investigated, and corrosion resistances of the coated samples were evaluated by immersion test and potentiodynamic polarization experiment. The corrosion resistance of the coated AZ31 samples was found to increase with increasing $Zn^{2+}$ concentration and the lowest corrosion rate was obtained for the samples coated at pH of 3.07, independent of $Zn^{2+}$ concentration. The best coatings on AZ31 were obtained at [$Zn^{2+}$] = 0.068 M and pH 3.07. At the conditions of [$Zn^{2+}$] = 0.068 M and pH 3.07, the formation and growth processes of ZPCCs on AZ31 Mg alloy are divided into four stages: formation of a dense layer, precipitation of fine crystals on the dense layer, growths of the inner and outer layers, and reorganization of outer crystalline layer.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.9
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• pp.1303-1310
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• 2009

Two experiments were conducted to determine the effect of dietary zinc level on growth performance and immune function in normal (Experiment 1) and immunologically challenged (Experiment 2) weanling pigs. Treatments consisted of the following: i) a corn-soybean meal basal diet containing 36.75 mg/kg total Zn, ii) basal diet+60 mg/kg added Zn as $ZnSO_{4}$, iii) basal diet+120 mg/kg added Zn as $ZnSO_{4}$. Each diet was fed to six pens of four pigs per pen (Exp. 1) or six pens of three pigs per pen (Exp. 2). In Exp. 1, the dietary zinc level had no effect on average daily growth (ADG), average daily feed intake (ADFI), or feed conversion ratio (FCR). Concentrations of tissue and serum zinc were not affected. Peripheral blood lymphocyte proliferation (PBLP) was not affected by dietary treatments. Supplementation of 120 mg/kg Zn decreased (p<0.05) the antibody response to bovine serum albumin (BSA) on d 7 compared with pigs fed the basal diet, but not on d 14. In Exp. 2, LPS challenge had no effect on ADG, ADFI and FCR in the entire trial (from d 0 to 21). LPS challenge significantly decreased ADG and ADFI (p<0.01) from d 7 to 14, but FCR was not affected. LPS challenge increased PBLP (p<0.05) and serum concentration of interleukin-1 (IL-1) (p<0.01), whereas the antibody response to BSA and serum concentration of interleukin-2 (IL-2) were not affected. Supplementation of Zn did not affect ADFI and FCR from d 7 to 14, but there was a trend for ADG to be enhanced with Zn supplementation (p<0.10). Supplementation of Zn tended to increase PBLP (p<0.10). Dietary treatment had no effect on the antibody response to BSA or concentrations of serum IL-1 and IL-2. Results indicate that the level of Zn recommended by NRC (1998) for weanling pigs was sufficient for optimal growth performance and immune responses. Zn requirements may be higher for pigs experiencing an acute phase response than for healthy pigs.

• Transactions on Electrical and Electronic Materials
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• v.4 no.6
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• pp.13-16
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• 2003

Mn-doped $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) thin film phosphors have been grown using a pulsed laser deposition technique under various growth conditions. The structural characterization carr~ed out on a series of $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) films grown on MgO(l00) substrates usmg Zn-rich ceramic targets. Oxygen pressure was varied from 50 to 200 mTorr and Zn/Ga ratio was the function of oxygen pressure. XRD patterns showed that the lattice constants of the $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) thin film decrease with the substitution of sulfur and selenium for the oxygen in the $ZnGa_2O_4$. Measurements of photoluminescence (PL) properties of $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) thin films have indicated that MgO(100) is one of the most promised substrates for the growth of high quality $ZnGa_2O_{4-x}M_{x}$:$Mn^{2+}$ (M=S, Se) thin films. In particular, the incorporation of Sulfur or Selenium into $ZnGa_2O_4$ lattice could induce a remarkable increase in the intensity of PL. The increasing of green emission intensity was observed with $ZnGa_2O_{3.925}Se_{0.075}:$Mn^{2+}$ and $ZnGa_2O_{3.925}S_{0.05}$:$Mn^{2+}$ films, whose brightness was increased by a factor of 3.1 and 1.4 in comparison with that of $ZnGa_{2}O_{4}$:$Mn^{2+}$ films, respectively. These phosphors may promise for application to the flat panel displays.