• Journal of the Korean Dietetic Association
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• v.9 no.1
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• pp.71-80
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• 2003

Food intake patterns and iron nutritional status of male and female college students were studied based on dietary iron density. Dietary data were collected using the method of 24-hour recalls for 3 consecutive days from 106 students, and fasting blood were drawn to measure iron nutritional status indicators such as total iron binding capacity, serum iron, hematocrit, hemoglobin, and red blood cell count. Mean daily iron intakes of male and female students were 13.3㎎ and 10.0㎎, which were 107% and 63% of the RDA, respectively. However, dietary iron density were similar between male and female students as 5.9㎎/1,000㎉ and 5.7㎎/1,000㎉, respectively. The diets were divided into two groups according to iron density; high iron density group (6㎎/1,000㎉ or more) and low iron density group (less than 6㎎/1,000㎉). The students in high density group had lower intakes of energy, especially fat, than those in low density group. Female students in high density group showed significantly higher intakes of iron, and non-heme iron and folate than those of low density group. The students in high density group consumed more rice, hamburger, and eggs, while those in low density group consumed more Ra-myon and alcoholic beverages. The students in high density group consumed greater proportions of iron from plant-origin foods. Vegetables, legumes and seasonings were the food groups that female students in high density group consumed significantly more than those in low density group. Also the percentages of female students with iron deficiency were higher in low density group. These results suggest that diet with high iron density is important to improve iron nutritional status of women, and further research about the effective way to increase iron density in our diet is needed.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.604-606
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• 2002

Air-cored machines have a higher efficiency with high frequency. speed than iron-cored machine because of the iron losses which may produce too much heat as well as the copper losses occurred in the rotor winding. But air-cored machine is lower flux than iron machine. The nature of the machine from 'iron-cored' to 'air-cored' is a progressive feature in the machines. A general analysis of the fields that is applicable to all configurations is presented. Slotless machines have been applied for no ripple induced voltage. In this paper, slotless mahcines equipped with internal 4-pole amature winding. This paper pay attention to analyze flux density of air-cored and iron-cored synchrous machine analytically and compare flux density of aired-cored machine to iron-cored machine.

• Nutritional Sciences
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• v.8 no.1
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• pp.71-76
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• 2005

The purpose of this study was to investigate the relationship between nutritional status of iron and bone minernl density in premenopausal women. In the study, we classified the subjects into osteopenia (-2.5-I, n=29) groups according to their lumbar spine bone mineral density. Anthropometric measurements, dietary intake analysis and blood biochemistry measurements were performed on the subjects. The average ages of those in the osteopenia and normal groups were 22.2 yrs and 23.0 yrs, respectively, with no significant difference. The average body mass index (p<0.05) of those in the osteopenia group (19.6) was significantly lower than that of the normal group (21.3). The mean protein intake of those in the osteopenia group was significantly lower than that (p<0.05) the subjects in the normal group. The osteopenia group consumed a significantly lower amount of iron (p<0.05) and non-heme iron (p<0.05) compared to the normal group. The intakes of total food, vegetables and milk of those in the osteopenia group were significantly lower than those of the subjects in the normal group. The serum ferritin (p<0.001) level of those in the osteopenia group was significantly lower than those of the subjects in the normal group. In conclusion, a balance of iron status may be helpful in the prevention of bone mass loss in premenopausal young women.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.393-400
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• 1999

The surface characteristics of nitrogen ion implanted iron aluminides were investigated using various electrochemical methods in $H_2$$SO_4$+KSCN and HCl solutions. Nitrogen ion implantation was performed with doses of $3.0$\times$10^{17}$ /ions/$\textrm{cm}^2$ at an energy of 150keV. Nitrogen ion implanted iron aluminides increased the corrosion potential and significantly decreased grain boundary activation, the active current density, and passive current density. Nitrogen implanted iron aluminides with Mo increased the corrosion, pitting potential, repassivation potential and │$E_{pit}$-$E_{corr}$│ value. Whereas, implanted iron aluminides containing boron reduced the pitting and repassivation potential in comparison with nitrogen implanted iron aluminides with Cr and Mo.o.

• Journal of Nutrition and Health
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• v.40 no.4
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• pp.371-384
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• 2007

This study was conducted to examine nutrient intake status and iron food sources by dietary iron density of high school girls in Seoul. The subjects of 226 girls were divided into High group (${\geq}$ 6 mg/1,000 kcal, N=115) and Low group (< 6 mg/1,000 kcal, N=111) by dietary iron density. The nutrient intake data obtained by 24-hour recall method were analyzed by Can Pro 3.0 software. Mean age of all subjects was 16.4 years old, heights and weights of High group and Low group were 164.5 cm, 53.4 kg and 161.7 cm, 51.7 kg, respectively. The body mass index (BMI) of High group and Low group was 20.5 kg/m$^2$ and 19.8 kg/m$^2$, respectively. Most nutrient intakes except energy and lipid intakes of High group were higher than those of Low group. High group showed significantly higher intakes of total iron, vegetable iron and animal iron than Low group. Ca and folate intakes of High group were under 75% of the recommended intake (RI) and Ca, iron, folate and vitamin C intakes of Low group were under 65% of RI. The percentage of subjects who consumed iron less than estimated average requirements (EAR) were 40.0% in High group and 77.5% in Low group. Total food intakes of High group showed higher than that of Low group. Total animal food intakes were significantly higher and total vegetable food intakes were significantly lower in Low group than those of High group. Iron intake from meats, fishes, shell fishes and seasonings were significantly higher in High group than Low group. Iron intake from milk and dairy products were significantly lower in High group than Low group. Major food sources of iron were rice, bean curd, pork, and egg in order among both groups.

• Journal of Powder Materials
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• v.20 no.1
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• pp.1-6
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• 2013

The key concept of nanopowder agglomerate sintering (NAS) is to enhance material transport by controlling the powder interface volume of nanopowder agglomerates. Using this concept, we developed a new approach to full density processing for the fabrication of pure iron nanomaterial using Fe nanopowder agglomerates from oxide powders. Full density processing of pure iron nanopowders was introduced in which the powder interface volume is manipulated in order to control the densification process and its corresponding microstructures. The full density sintering behavior of Fe nanopowders optimally size-controlled by wet-milling treatment was discussed in terms of densification process and microstructures.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.758_759
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• 2009

In the design and analysis of electric machines the precise calculation of iron loss has incredible significance. It is tough to foresee iron losses precisely in machines due to distribution of non sinusoidal flux density. It is necessary to approximate the iron losses for the precise computation of efficiency. This paper presents a novel approach for the prediction of iron losses of the brushless dc (BLDC) motors by considering the effects of minor hysteresis loops in the simplified model. The novel iron loss model results are compared with the simplified model and with finite element method (FEM).

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.740-741
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• 2006

The achievement of high density at reasonable cost is one of the major challenges of the P/M industry. One of the key factors contributing to the compressibility of a mix is the lubricant. New experimental lubricants enabling higher green density by conventional compaction or temperature-controlled die compaction were identified. The compaction and ejection characteristics of these new lubricants as measured with a fully instrumented lab press are presented and compared to that of conventional lubricants.

• Journal of the Korean institute of surface engineering
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• v.56 no.4
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• pp.265-272
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• 2023

Photoelectrochemical (PEC) water splitting is one of the promising methods for hydrogen production by solar energy. Iron oxide has been effectively investigated as a photoelectrode material for PEC water splitting due to its intrinsic property such as short minority carrier diffusion length. However, iron oxide has a low PEC efficiency owing to a high recombination rate between photoexcited electrons and holes. In this study, we synthesized nanoporous structured iron oxide by anodization to overcome the drawbacks and to increase surface area. The anodized iron oxide was annealed in Ar atmosphere with different purging times. In conclusion, the highest current density of 0.032 mA/cm² at 1.23 V vs. RHE was obtained with 60 s of pursing for iron oxide(Fe-60), which was 3 times higher in photocurrent density compared to iron oxide annealed with 600 s of pursing(Fe-600). The resistances and donor densities were also evaluated for all the anodized iron oxide by electrochemical impedance spectra and Mott-Schottky plot analysis.

• Journal of Information Display
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• v.6 no.2
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• pp.19-24
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• 2005

The density controlled carbon nanotubes (CNTs) are grown on the iron acetate nanoparticles by using the freeze-dry method. The iron-acetate [Fe(II)$(CH_3COO)_2$] solution is used to prepare the catalytic iron nanoparticles. The density of CNTs is controlled in order to enhance the field emission process. Furthermore, the patterning of the iron nanoparticle catalyst-layer for the fabrication of electronic devices is simply achieved by using alkaline solution, TMAH (tetramethylammonium hydroxide). We applied this patterning process of catalyst layer to form the electron emitter with under-gate type triode structure.