• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.2009_2010
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• 2009

Thin-gauged 3% Si-Fe sheets having a high magnetic induction of over 1.9 T have been developed for the purpose of applications where operation frequency is higher than power frequency. In order to clarify requirements of iron loss characteristics for the applications, iron loss characteristics of the newly developed strip were investigated by iron loss separation method and were compared with those of commercially produced 0.3 mm-thick electrical sheets. In case of relatively high excitation induction(1.7 T) and low frequency(60 Hz), reducing hysteresis loss is effective to decrease total iron loss. In case of relatively low excitation induction(1.0 T) and high frequency(1 kHz), reducing eddy-current loss is effective by decreasing thickness and grain size to improve total iron loss.

• Journal of Community Nutrition
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• 제1권2호
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• pp.140-147
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• 1999

It has been known for some time that elevated body iron could be a risk factor for coronary heart disease. The present study was conducted to determine body iron status and dietary iron intake of patients with myocardial infarction(MI). Seventy five patients from the Chunam area with their first MI history within he past 2 months were recruited. The serum iron concentration, total iron binding capacity(TIBC) and percent transferrin saturation(TS) were selected as indicators of body iron status. Twenty four hour recall was conducted by trained interviewers to asses the dietary intake. Most women (91.3%) showed waist to hip ratio(W/H) greater than 0.85 while 17.3% of men were assessed to have a tendency of abdominal obesity(W/H>0.95). The average BMI of women was 25.80 and that of men was 23.98. The average diet intake of participants was below the recommended dietary allowances (RDA) for most nutrients. He average dietary iron intake was 10.03 mg/day for all subjects while women's iron intake was significantly lower than men's. However, a great proportion of participants (77%) showed a tendency to have normal iron status. About 9% of the participants were assessed as iron deficient and 14% had an iron overload. The mean serum iron concentration was 125 g/dl ranging from 13.3 to 280.6 g/dl. Iron intake from animal sources were significantly associated with body iron status (r=0.257, p=0.026) when TIBC was used as an iron status indicator. When iron status was assessed with TS, it was directly associated with iron intake from animal sources(r=0.278, p=0.05) for he subjects in the normal iron status group. He results of the present study showed that the nutrient intake of Mi patients in Chunan was not quite adequate while iron status was mostly in the normal range. Further studies are needed to investigated whether there is a possible difference in iron metabolism of the MI patients.

• 대한지역사회영양학회지
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• 제14권3호
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• pp.327-339
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• 2009

It is known that Korean pregnant women take iron supplements at a higher than the recommended level. This study was designed to provide data on current iron intake levels both from food sources and supplement to better guide iron supplement use during pregnancy. We also explored associations of iron supplement intake levels with various sociocultural factors and pregnancy outcomes. Dietary intakes of 510 pregnant women were assessed by a validated 102-item food frequency questionnaire, and information on types and amounts of nutritional supplement intakes were also attained. While dietary intake levels of most nutrients exceeded the KDRIs (Korea Dietary Reference Intakes: EAR: Estimated Average Requirements), folate fell short of the KDRIs. A total of 428 women (83.9%) reported to take iron supplement. The pregnant women were divided into the three groups (group I: Fe supplement intake ${\le}$ EAR, group II: EAR < Fe supplement intake ${\le}$ 3 times of EAR, group III: 3 times of EAR < Fe supplement intake). The mean dietary intake of iron was 24% of the total iron intake for pregnant women. Iron intake from food was not significantly different among I, II, and III. In case of iron intake from supplements, the most frequent dose (34.1%) was 90-100 mg/day, and the mean iron supplement intake was 362% of the EAR. The study findings showed that those with higher levels of iron supplements had better meal quality measured by NAR (Nutrient Adequacy Ratio) and INQ (Index of Nutrient Quality). In addition iron supplement intake levels were significantly related to age (20s: 66.5 ${\pm}$ 38.6 mg/day, 30s: 77.3 ${\pm}$ 47.8 mg/day, p < 0.0116) and experience of childbirth (1st pregnancy: 70.9 ${\pm}$ 41.2 mg/day, 2nd pregnancy: 64.5 ${\pm}$ 39.5 mg/day, ${\ge}$ 3rd pregnancy: 94.4 ${\pm}$ 63.8 mg/day, p < 0.005). However, no significant difference was found between iron supplement intake levels and various pregnancy outcomes including birth weight, birth height, gestational age, weight gain during pregnancy, and jaundice. It is worrisome that iron intake by supplement use greatly exceeded the EAR, suggesting the need of appropriate guidelines for iron supplement intake during pregnancy. Thus iron overdose from supplements in pregnancy should be considered as a serious condition.

• Journal of Nutrition and Health
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• 제32권8호
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• pp.887-896
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• 1999

The purpose of this research is to assess hematological and biochemical status and the prevalence of iron deficiency of pregnant women by gestational age to provide the primary data about iron nutritional status of pregnant women. Pregnant women visiting public health centers in Ulsan participated in study and were divided into 3 trimester by last menstrual period(LMP). Hemoglobin (Hgb), hematocrit(Hct)and mean corpuscular volume(MCV) among iron status indices were not statistically different from normal distribution, however total iron binding capacity(TIBC) and serum ferritin were skewed to left and serum iron and transferrin saturation(TS) were skewed to right. Hgb was positively correlated with Hct(r=0.93, p<0.001) but TIBC was negatively correlated with all indices. Serum ferritin was also correlated with all indices, especially in 3rd trimester but not reached to 1st trimester level. Mean corpuscular hemoglobin(MCH), mean corpuscular hemoglobin concentration(MCHC), Red cell distribution width(RDW), serum iron and TS were not significantly different by trimester, however when serum serum iron was adjusted with hematocrit to correct the hemodilution, it significantly decreased in 2nd trimester. MCV increased in 2nd trimester and was maintained until late pregnancy, TIBC continued to increase throughout the trimester. The prevalence of anemic by CDC(Centers for Disease Control) Hgb criteria(Hgb <11.0g/dl in 1st and 3nd trimester, Hgb<10.5g/dl in 2nd trimester) was 2.8% in 1st trimester, 22.5% in 2nd trimester, 27.1% in 3rd trimester and was similar with prevalence by CDC Hct criteria(Hct < 33% in 1st and 3rd, Hct < 32% in 2nd). The prevalence of anemic of total subjects was 32.7% by WHO criteria(Hgb < 11.0g/dl). Although almost iron status indices increased in 3rd trimester, the prevalence of anemia by different criteria of all indices increased throughout the trimester, so iron nutritional status was considered as serious during late pregnancy. However, since factors other than iron deficiency, such as infection, infection, inflammation, other nutrient deficiency may also play a significant role, to differentiate the anemia due to mainly iron deficiency from the anemia due to other factors, serum ferritin is among the more useful indices in distinguishing the two conditions because it is depressed only in iron deficiency. Hgb<11.0g/dl and serum ferritin<12.0ug/L as the criteria of iron deficiency was suggested by CDC. 17.8% of all subjects were classified as iron deficient anemia, 14.9% as anemic from other reasons, 21.2% as iron deficiency any only 46.2% were in normal iron status.

• Animal cells and systems
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• 제8권2호
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• pp.97-103
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• 2004

The cytotoxic effect of iron was examined in peritoneal macrophage to determine contributing factors by iron injection to rat. Viability was reduced by 24% by the iron-overload and by 30% by short-term iron addition. Total iron was increased by 45% in the iron-overloaded with remarkable elevation (9 to 14 fold) in the presence of $FeSO_4$. Free calcium was also increased by 19% in control and 44% in iron-overloaded group due to additional $FeSO_4$ NO and MDA were increased by 40% and 136%, respectively, with significant reduction (37%) of NAD(P)H. RCR and cytochrome c oxidase activity were lowered approximately by 10% with reduction of mitochondrial membrane potential. Addition of iron was frequently associated with altered distribution of mitochondria of high membrane potential in the iron-overloaded macrophage. These results suggest altered mitochondria with high NO and low NAD(P)H due to iron.

• 동아시아식생활학회지
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• 제9권3호
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• pp.302-314
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• 1999

This study was conducted to evaluate nutrient intake, indices of anemia, serum lipids, and their correlations in 40 Korean female college students aged 21 to 25 years. Fasting blood samples were collected in October. 1997 Nutrient intake was investigated by 24-hour recall method for three days. Anthropometric measurements, blood pressure, iron status and serum lipids of the subjects were determined. The mean values for age. height, weight, BMI and blood pressure of the subjects were 22.1 years, 160.6cm, 54.4kg and 109.1/66.9mmHg, respectively. According to the body composition analysis, total body water, % body fat, lean body mass and WHR were 26.7L. 29.5%, 36.5kg and 0.8, respectively. Average daily intake of energy was 1,858.4kcal. Protein, phosphorus, vitamin B$_1$, vitamin B$_2$, niacin and vitamin C intakes were higher than the Korean recommended dietary allowence(RDA), whereas calcium, iron, vitamin A intakes were tower than that. Hemoglobin(Hb), hematocrit(Hct), serum iron(SI) and total iron binding capacity(TIBC) were measured and transferrin saturation (TS%) was calculated from serum. The mean values for Hb, Hct, SI, TIBC and TS were 13.6$\mu\textrm{g}$/㎗, 41.6%,97.8$\mu\textrm{g}$/㎗, 319.6$\mu\textrm{g}$/㎗ and 31.9%, respectively. The Prevalence rates of iron deficiency assessed by Hb and Hct were found to be 10% and 2.5%, respectively. However, when assessed with TIBC, the prevalence rate of iron deficiency was increased to 32.5%. The mean values for serum triglyceride(TG), total cholesterol(TC), HDL-Chol, LDL-Chol concentrations and atherogenic index(AI) were 154.7mg/㎗, 80.0mg/㎗, 47.4mg/㎗, 91.3mg/㎗ and 2.6, respectively. Correlations among indices of anemia. there were positive correlations between Hb and Hct, between SI and TS : negative correlations between TIBC and TS or SI. Correlations among serum lipids, there were positive correlations between TC and TG or LDL-cholesterol. Energy intakes were correlated positively with TIBC(p＜0.05), and vitamin C intakes negatively correlated with Hb(P＜0.05). And vitamin A intakes were negatively correlated with TG(p＜0.01). TC(p＜0.05) and LDL-Chol(p＜0.01). Hb negatively correlated with TG(P＜0.05). Body weights(p＜0.05), lean body mass(p＜0.05) and total body water(p＜0.01) werenegatively correlated with Hb. BMI and WHR correlated with TG and TC(p＜0.01). These results indicated that subjects with higher energy intake and overweight had a tendency to have iron deficiency. Increases in BMI and WHR were related to increases in serum lipids levels and decreases in TIBC. The results also showed that serum lipids were decreased when vitamin A and iron intakes were sufficient.

• 한국식품영양과학회지
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• 제28권3호
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• pp.542-546
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• 1999

Uncoated, ethyl cellulose(EC) coated or methacrylic acid copolymer(MAC) coated ferrous sulfate was added to the yoghurt made from whole milk powder and quality changes of those yoghurt were observed. Among treatments uncoated ferrous sulfate added yoghurt showed the lowest quality in the view of pH, total acidity, total counts of lactic acid bacteria, and sensory characteristics. Quality change of MAC comparing to control was lower than that of EC. MAC and EC showed higher TBA value than no iron added or uncoated iron added one during storage. From sensory evaluation, MAC was not signif icantly different from control in color and off flavor after one day storage(p>0.05), however significant difference was observed in off flavor after 7 day storage(p<0.05). From above results, MAC coated ferrous sulfate added yoghurt showed better quality than uncoated or EC coated ferrous sulfate added one during storage.

• 대한지역사회영양학회지
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• 제5권3호
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• pp.493-501
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• 2000

The purpose of this study was to assess the nutritional status of iron of the elderly residing in the Jeonju area. The anthropometric parameters, nutrient intake and biochemical status of iron, were measured for 60 korean elderly(23 elderly men and 37 elderly women aged 60 - 79 years old). The level of hemoglobin(Hb), hematocrint(Hct), serum iron(Fe), total iron binding capacity(TIBC) and serum ferritin(Ferritin) were measured and transferrin saturation(TFsaturation) was calculated. Mean values of Hb, Hct, Fe, TIBC, TFsaturation and Ferritin were 14.49$\pm$0.93g/이, 42.47$\pm$2.59%, 125.48$\pm$52,.46$\mu\textrm{g}$/dl, 338.13$\pm$45.92$\mu\textrm{g}$/dl, 193.00$\pm$125.03$\mu\textrm{g}$/l in elderly men and 12.82$\pm$0.99$\mu\textrm{g}$/dl, 37.66$\pm$2.90%, 100.08$\pm$42.82$\mu\textrm{g}$/dl, 356.41$\pm$54.65$\mu\textrm{g}$/dl, and 99.35$\pm$117.22$\mu\textrm{g}$/l in elderly women, respectively. Prevalence of iron deficiency varied greatly with biochemical indices of iron. It was 13.0% when judged by Fe(60 $\mu\textrm{g}$/dl) and TFsaturation(15%) whereas 34.78% by Hct(41%) in elderly men. However 13.5% of the elderly women showed iron depletion(Ferritin<20$\mu\textrm{g}$/l) and 43.2% showed suppressed erythropoiesis with iron deficiency(TIBC>360$\mu\textrm{g}$/dl). The anemic subjects assessed with TFsaturation(<15%) represented 13.5% of the elderly women, whereas 18.9% of the subjects possessed less than 12g/dl of Hb. The Hb concentration was positively correlated with Hct(r=0.980, p<0.001), Fe(r=0.384, p<0.01) and TFsaturation(r=0.349, p<0.01). On the other hand, Ferritin concentration showed a significantly negative correlation with TIBC(r=0.349, p<0.05) and a positive correlation with TFsaturation(r=0.362, p<0.01). Major food groups of iron intake in the elderly were vegetables, cereals, and fish. The mean daily intake of iron was not significantly different between elderly men and women(12.82mg vs 10.35mg). Intake of heme iron however, was significantly higher(p<0.01) in elderly men(1.03mg) than women(0.42mg). Total absorbable iron caculated by the method of Monsen was 0.55mg, 0.40mg in elderly men and women, respectively and bioavailability of dietary iron 4.29% and 3.87%.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1345-1351
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• 2013

Variable iron loss as function of current phase angle of Interior Permanent Magnet Synchronous Motor(IPMSM) was calculated through Curve Fitting Method(CFM). Also, a magnetic flux density distribution of iron core according to current phase angle was analyzed, and an iron loss calculation was performed including harmonic distortion. The experiment was performed by production of non-magnetizing model for the separation of mechanical loss, and the iron loss was calculated by the measurement of input using power analyzer and output power using dynamometer. Some error was generated between experimental results and calculation value, but an iron loss diminution according to current phase angle followed a same pattern. So, errors were generated by measurement, vibration, noise, harmonic distortion loss, etc.

• 한국주조공학회지
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• 제1권2호
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• pp.2-9
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• 1981

Graphite spheroidization and scaling resistance of cast iron containing 5-10% Al were investigated. It is impossible to obtain spheroidal graphite in cast iron containing Al with 8 % and over, but possible to obtain spheroidal graphite even in cast iron with an Al content of about 10 % by increasing Si content. In the scaling test carried out under the heating condition of $950^{\circ}C$ in air for total of 50 hours, the scaling resistance of cast iron containing Al with 8 % and over was remarkably superior, and also spheroidal graphite cast iron was superior to flake graphite cast iron. The scale became thinner more compacts and more protective with increasing Al content.