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

• Journal of Conservation Science
• /
• v.34 no.1
• /
• pp.39-50
• /
• 2018

This study replicated traditional smelting methods to produce iron blooms from sand iron. The metallurgical properties of the slag and the iron blooms were analyzed. The sand iron materials used in the smelting experiments, which were based on ancient documents, were collected from Gyeong-Ju and Pohang. Analysis by WD-XRF and XRD showed that Gyeong-Ju's sand iron contains a high-titanium, with magnetite, and Pohang's sand iron contains a low-titanium, which magnetite and ilmenite were mixed. Analysis of the slag with XRD, and the micro-structure with metal microscopes and SEM-EDS, confirmed that the major compounds in the slag of the Gyeong-Ju's sand iron were fayalite and $w\ddot{u}stite$, and those in the slag of the Pohang's sand iron were titanomagnetite and fayalite. The differences in the main constituents were confirmed according to the Ti quantity. Finally, we observed the microstructures of the iron blooms. In the case of the iron bloom produced from Gyeong-Ju's sand iron, the outside was found to be dominantly a pearlite of eutectoid steel, while the inside was a hypo-eutectoid steel where ferrite and pearlite were mixed together. While, the major component of the iron bloom produced from Pohang's sand iron was ferrite, which is almost like pure iron. However, there were many impurities inside the iron blooms. Therefore, this experiment confirmed that making ironware required a process that involved removing internal impurities, refining, and welding. It will be an important data to identify the characteristics of iron by-products and the site through traditional iron-making experiments under various conditions.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.22 no.3
• /
• pp.349-358
• /
• 1993

Iron deficiency is still a common nutritional disorder in the world. In developing countries, the bioavailability of dietary iron is often very low, mainly due to a low content of factors facilitating nonheme iron absorption. The iron content of the diet, iron status of subjects, and the actual composition of the diet are the major factors that influence the absorption of food iron. Inadequate dietary intake of iron often results from low-calorie diets, food restrictions, or single food diets. Ascorbic acid and MFP (meat, fish and poultry) are the quantitatively most important enhancers of nonheme iron absorption found in the diet. Ascorbic acid and meat have consistently been shown to enhance iron bioavailability. Major inhibitors of nonheme iron absorption are dietary fiber, phytate, and polyphenols. The availability of nonheme iron can be highly influenced by components of foods ingested concomitantly, Therefore, consumption of food in combinations can either enhance or inhibit nonheme iron absorption.

• Nutritional Sciences
• /
• v.1 no.1
• /
• pp.52-55
• /
• 1998

This study was performed to investigate the effect of dietary iron intake on the immune status of male college students. Twenty healthy male university students participated in the study. The mean age of the subjects was 22.6 years old, mean height was 173.3 cm and mean body weight was 68.4 kg. The mean daily iron intake of the subjects was 19.9 mg, 158.1% of the Korean recommended dietary allowances (RDA). The blood iron status and immune responses of the subjects were analyzed and compared between the high dietary iron group consuming more than 100% of the RDA of iron (Hi-Fe) and the low dietary iron group consuming less than 100% of the RDA of iron (Low-Fe). The serum iron concentration and percent saturation of transferrin were within the normal range in both groups. However, the Hi-fe group had higher serum iron and percent saturation of transferrin than the Low-fe group (p<0.05). When differential white blood cell counts were compared, the Low-Fe group had a lower percentage of neutrophils than the Hi-Fe group (p <0.1). The plasma IL-2 concentration, immunoglobulin levels and lymphocyte subsets were not affected significantly by the differences in iron intake as shown in this study. Serum iron had a positive correlation with monocyte percentage but had a negative correlation with IgM concentration. The results of this study suggest that slightly-low dietary iron intake without anemia has no effects on the cell-mediated and humoral immunities of healthy male university students. However, natural defenses, such as neutrophils and monocytes, seem to be more sensitively affected by changes in dietary iron intake.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.53 no.5
• /
• pp.295-304
• /
• 2004

This paper deals with characteristic analysis method using d-q axis equivalent circuit considering iron loss in a single-phase line-start permanent magnet synchronous motor. The iron loss resistance to account for the iron loss is included in the equivalent circuit to improve the modeling accuracy. Furthermore, for the improved calculation of the iron loss, the iron loss is calculated from the magnetic flux density by 2-dimensional finite element method. The result is represented as the iron loss resistance and connected in parallel with the total induced voltage. Therefore, the currents can be expressed as the summation the output current with the current corresponding to the iron loss. Finally, the steady state characteristic analysis results are compared with the experimental results to verify this approach.

• Economic and Environmental Geology
• /
• v.12 no.1
• /
• pp.13-15
• /
• 1979

Iron ore waste discarded around Choong-ju iron district, Choongchong-Bukdo is as low as 25 per cent of iron, mainly consisting of hematite and magnetite. In this mineral dressing test procedure 93 per cent of magnetite was separated and concentrated into the magnetite concentrate as high as 62 per cent. The remaining sample, mostly, hematite averages about 19.8 per cent of iron which can be concentrated with very good results with the optimum flotation conditioning-pH 3.0 and 3 cc per litre of aero-promoter #845 (0.5% sol.) and 1.5cc per litre of hydro-fluoric acid (40% sol.) and four times of cleaning flotation. Hematite concentrate averages 64.2 per cent of iron. The overall iron concentrate averages 63 per cent of iron with recovery 86 per cent of iron contained.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.2
• /
• pp.123-129
• /
• 2005

In situ permeable reactive barrier (PRB) technologies have been proposed to reductively remove organic contaminants from the subsurface environment. The major reactive material, zero valent iron ($Fe^0$), is oxidized to ferrous iron or ferric iron in the barriers, resulting in the decreased reactivity. Iron-reducing bacteria can reduce ferric iron to ferrous iron and iron reduced by these bacteria can be applied to dechlorinate chlorinated organic contaminants. Iron reduction by iron reducing bacteria, Shewanella algae BrY, was observed both in aqueous and solid phase and the enhancement of TCE removal by reduced iron was examined in this study. S. algae BrY preferentially reduced Fe(III) in ferric citrate medium and secondly used Fe(III) on the surface of iron oxides as an electron acceptor. Reduced iron formed reactive materials such as green rust ferrihydrite, and biochemical precipitation. These reactive materials formed by the bacteria can enhance TCE removal rate and removal capacity of the reactive barrier in the field.

• The Korean Journal of Nuclear Medicine
• /
• v.5 no.2
• /
• pp.19-40
• /
• 1971

Since the iron balance is maintained by regulated intestinal absorption rather than regulated excretion, there have been many reports concerning the factors which may influence the intestinal iron absorption. As the liver is the largest iron storage organ of the body, any hepatocellular damage may result in disturbances in iron metabolism, e,g., frequent co-existence of hemochromatosis and liver cirrhosis, or elevated serum iron level and increased iron absorption rate in patients with infectious hepatitis or cirrhosis. In one effort to demonstrate the influence of hepatocellular damage on intestinal iron absortion, the iron absorption rate was measured in the rabbits whose livers were injured by a single subcutaneous injection of carbon tetrachloride (doses ranging from 0.15 to 0.5cc per kg of body weight) or by a single irradiation of 2,000 to 16,000 rads with $^{60}Co$ on the liver locally. A single oral dose of $1{\mu}Ci\;of\;^{59}Fe$-citrate with 0.5mg of ferrous citrate was fed in the fasting state, 24 hours after hepatic damage had been induced, without any reducing or chelating agents, and stool was collected for one week thereafter. Serum iron levels, together with conventional liver function tests, were measured at 24, 48, 72, 120 and 168 hours after liver damage had been induced. All animals were sacrificed upon the completing of the one week's test period and tissue specimens were prepared for H-E and Gomori's iron stain. Following are the results. 1. Normal iron absorption rate of the rabbit was $41.72{\pm}3.61%$ when 0.5mg of iron was given in the fasting state, as measured by subtracting the amount recovered in stool collected for 7 days from the amount given. The test period of 7 days is adequate, for only 1% of the iron given was excreted thereafter. 2. The intestinal iron absorption rate and serum iron level were significantly increased when the animal was poisoned by a single subcutaneous injection of 0.15cc. per kg. of body weight of carbon tetrachloride or more, or the liver was irradiated with a single dose of 12,000 rads or more. The results of liver function tests which were done simultaneously remained within normal limit except SGOT and SGPT which were somewhat increased. 3. In each case, there has been good correlation between the extent of liver cell damage and degree of increased iron absorption rate or serum iron level. 4. The method of liver damage appeared to make no obvious difference in the pattern of iron deposit in liver. This may be partly due to the fact that tissue specimens were obtained too late, for by this time the elevated serum iron level had returned within normal range and the pathological changes were almost healed. 5. The possible factors and relationship between intestinal iron absorption and hepatic parenchymal cell damage has been discussed.

• Journal of Nutrition and Health
• /
• v.29 no.7
• /
• pp.713-720
• /
• 1996

To study the effect of caffeine intake levels on iron metabolism, the iron utilization, iron contents of serum, liver, spleen, kidney, hemoglobin and hematocrit were compared in rats of different sex fed various levels of caffeine (3.5 and 7.0mg/100g body weight) for three weeks. There were no significant caffeine induced differences in feed intake, body weight gain but feed intake of male rats were significantly lower than that of female rats. Hemoglobin, hematocrit and iron contents of the serum were not significantly different between caffeine free and caffeine groups or male and female rats. Iron contents of kidney were decreased by elevation of injected caffeine levels rather than those of liver and spleen. caffeine male groups showed more increased uine volume, urinary and fecal excretions of iron than caffeine free or caffeine female groups. Apparent digestibility and retention of iron were significantly decreased by increment of injected caffeine levels. Male rate rats were more susceptible to injected caffeine on iron excretion than female rats. Current findings suggest that excessive caffeine consumption can affect iron excretion via urine and feces thereby decrease the utilization of iron, and have more significant effect on male than female rats.

• Animal cells and systems
• /
• v.8 no.2
• /
• pp.97-103
• /
• 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.