• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.2
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• pp.196-208
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• 1998

To improve the quality of environmental measurements and evaluation of the workplace air in the pigment manufacturing industries, we analyzed metal(chromium, cadmium, lead, iron, cobalt, manganese, antimony, titanium, arsenic, and selenium) concentrations by ICP-AES in sixty seven samples of inorganic bulk pigments which are produced and/or used in Korea. We also collected MSDS which has to be supplied by manufacturer and/or supplier and posted in the workplace according to the Hazard Communication Standards, and compared the number of metals listed in each MSDS with the number of metals determined by ICP-AES. Results were as followed; 1. Among seventeen yellowish-colored samples, chromium(2~19%) and lead(0.1~61%) were the two major metals. In thirteen reddish-colored samples, iron was the major component with 37~81%. Cobalt and manganese were detected in blue-colored samples with less than 1%, while antimony and titanium were the major two metals in white-colored pigments with 178~300 ppm and with 36~65%, respectively. 2. In area samples collected in workplace air(one pigments producing factory and five retailer stores), iron and manganese were detected but the concentrations not exceeded the TLVs(1 and $5mg/m^3$, respectively). In three of fifteen samples, the concentrations of lead exceeded the TLV ($0.05mg/m^3$). 3. Two out of seven companies provided MSDS, and the average provision rate was 22.4%. And the coincidence rate of the number of metals referenced in MSDS and determined by ICP-AES mostly accorded, but in one sample, different metal was detected from MSDS. In summary, metals have to be concerned in evaluation of the workplace air dealing with compounds of inorganic pigments dust are cobalt, chromium, iron, manganese, lead and antimony, and these are simultaneously determined by ICP-AES. Taking this opportunity, it is needed to reinforce that the personnel is to be concerned about prevention of workers' ill health regarding to provision of MSDS.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.57-61
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• 1999

The effect of the microstructure of gray cast iron on friction properties was investigated by using a pad-on-disk type friction tester. Cast iron samples used in this investigation were obtained from "step block" castings, which were designed to produce microstructure with different graphite flake morphologies from different cooling rate and solidification rate. Results of this work showed that the gray cast iron disks with long graphite flakes showed less fading. The rotors containing smaller amounts of ferrite showed higher friction coefficient and better fade resistance than others.an others.

• Journal of Nutrition and Health
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• v.32 no.7
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• pp.793-801
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• 1999

The purposes of this study are to assess iron status in mothers and their newborn infants at birth and to analyze the influence of maternal iron status on their newborn babies. Venous bloods samples were drawn from 144 pregnant women just before delivery and cord bloods of their newborn babies were collected immediately after birth for measurement of hemoglobin, hematocrit, serum iron, ferritin, total binding capacity and transferrin saturation. The values of hemoglobin and hematocrit were significantly lower in the mothers(10.9$\pm$1.43g/dl and 33.7$\pm$3.67%) than in their newborn infants(14.7$\pm$1.43g/dl and 45.3$\pm$4.76%)(p<0.0001). At delivery, serum iron levels in cord blood were about twice as high as those in the maternal blood, and serum ferritin levels in the cord blood were about four times higher than those in the maternal blood. The serum ferritin levels of multigravidas were higher than those of primigravidas,. but there was no difference between the serum ferritin levels of their infants. The serum ferritin levels of the mothers and their infants were higher in maternal group with iron supplement regularly than in other maternal group without iron supplement during pregnancy. Among the mothers, 26.4% had a serum ferritin levels below 12ng/ml(i.e. depleted iron stores)and 78.9% had a hemoglobin below 12g/dl(i.e.iron deficient anemia). When the maternal group was classified according to their serum ferritin levels by 9ng/ml, 12ng/dl or 20ng/ml, there was no significant difference in the iron status of their newborn infants among the three groups. The hemoglobin and serum ferritin levels of the mothers were well correlated with those of their babies. The maternal hemoglobin values negatively correlated with infant birth weight. It is possible that the demands of iron of the mother might be increased in the case of a newborn infant of greater size. The results of this study provide useful information regarding establishment of RDA for iron in pregnant women and guidance about the need for iron supplement during pregnancy.

• Journal of Nutrition and Health
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• v.30 no.8
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• pp.960-975
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• 1997

This study was carried out to evaluate the iron nutrition status of 212 middle school students(106 males and 106 females) residing in Seoul(13-14 years old ) using eating patterns and a measurement of anthropometrical determination and hematological indices. Fasting blood samples were taken from all subjects, serum iron (SI) and total iron binding capacity(TIBC) concentrations were measured, and transferrin saturation(TS) levels were calculated. Iron and other nutrient intakes were estimated by a semi-quantitative frequency questionnaire. The level of TS(%) which was calculated with TIBC and SI in females(20.4$\mu\textrm{g}$/dl) was significantly lower(p<0.050 than that of males (27.4$\mu\textrm{g}$/㎗). The prevalence of iron deficiency was found to be 36.7% when defined by TS(%) (<05%). Mean daily intake of total iron in the study subjects was 14mg and heme iron intake was 5.4mg(38.1%) . There was a significant negative correlation between the level of SI and the income level and a positive correlation with the level of TIBC and the income level. TIBC had a positive correlation with the anthropometric variables(Ht, Wt, BMI, RI and PIBW). SI and TS had a negative correlation with body fat percentage. There was a positive correlation between energy intake and TIBC only among females. The logistic regression analysis revealed that income level, body fat percentage , weight and energy intake were major determinants of low SI levels. Among the determinants of abnormal TIBC levels were weight , height, income level and energy intake. Finally , among those of low TS% were iron and energy intake and income level. These observations suggest that physical status, body fat percentage energy and iron intakes and income level are risk factors for iron-deficiency anemia among the middle school students in Seoul.

• Journal of Korea Foundry Society
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• v.43 no.6
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• pp.279-285
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• 2023

In order to predict the mechanical properties of ductile cast iron heat treated in an intercritical temperature range, samples machined from cast iron with a tensile strength of 450 MPa were heat-treated at various intercritical temperatures and air-cooled, after which a microstructural analysis and Brinell hardness test were conducted. As the heat treatment temperature was increased in the intercritical temperature range, the ferrite fraction in the ductile cast iron decreased and the pearlite fraction increased, whereas the nodularity and nodule count did not change considerably from the corresponding values in the as-cast condition. The Brinell hardness values of the heat-treated ductile cast iron increased gradually as the heat treatment temperature was increased. Based on the measured alloy composition, the fraction of each stable phase and the hardness model from the literature, the hardness of the ductile cast iron heat treated in the intercritical temperature range was calculated, showing values very similar to the measured hardness data. In order to check whether it is possible to predict the hardness of heat-treated ductile cast iron by using the phase fraction obtained from thermodynamic calculations, the volumes of graphite, ferrite, and austenite in the alloy were calculated for each temperature condition. Those volume fractions were then converted into areas of each phase for hardness prediction of the heat-treated ductile cast iron. The hardness values of the cast iron samples based on thermodynamic calculations and on the hardness prediction model were similar within an error range up to 27 compared to the measured hardness data.

• Journal of the Korean Society of Food Culture
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• v.18 no.6
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• pp.575-583
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• 2003

To evaluate the effect of cereal supplementation on children's iron nutritional status of Korean institutionalized was designed. Dietary survey was carried out methods of food weighting in the breakfast or/and dinner, and record interview in lunch (n=74). A nutritional intervention study was carried out through supplementing cereal for 4 weeks in 24 children of 1 institution from 4 to 12 years. The children received 3.6mg elemental Fe(as 100g cereal) per day. Blood samples were drawn before and after supplementation. Nutrients which children's intake was less than two-thirds of Korean RDA were Vit A, Vit B1, Vit B2, Ca and Fe. The mean daily intakes of iron were 5.1mg for male and 4.9mg for female and 52.3% for male and 45.4% for female of Korean RDA. The proportions of children with iron depletion assessed by TIBC(>360mg/dl) and serum ferritin(<20ng/ml) were 56.6% and 58.7%, respectively. The proportions of children with the iron deficient erythropoiesis assessed by serum iron(<70ml/dl), Hb(<12g/dl), and Hct(<36%) were 76.0%, 58.7%, and 64.0%, respectively. After cereal supplementation, in anemic children, levels of Hct(p<0.001), serum iron(p<0.001) and transferrin saturation(p<0.001) were significantly increased. The effect of cereal supplementation in children with iron deficient erythropoeisis was more effective to improve the iron nutritional status than children with iron depletion. It was concluded that cereal supplementation program in anemic children was also effective to improve iron nutritional status.

• Journal of the Korean Dietetic Association
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• v.5 no.2
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• pp.164-174
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• 1999

The purpose of this study were to assess iron status and obesity in 82 middle aged women living in Kangnung area. Anthropometric measurements were taken for body weight, height, percentage of body fat and circumferences of waist and hip. Venous blood samples were drawn from subjects for measurement of hemoglobin(Hb), hematocrit(Hct), serum iron(Fe), total iron binding capacity(TIBC), transferrin saturation(TS) and serum ferritin. Dietary intakes of iron(heme iron and nonheme iron), the amounts of MPF(meat, poultry and fish) and ascorbic acid were assessed by modified 24-hr recall method. The results obtained are summarized as follows : Postmenopausal women had more body fat than premenopausal women. That is, postmenopausal women tend to be obeser than premenopausal women. There was no difference in Hb, Hct, Fe, TIBC and TS between pre- and postmenopausal women. But the serum ferritin concentration of postmenopausal women(83.7$\pm$42.1ng/ml) was significantly (p<0.05) higher than premenopausal women(56.4$\pm$41.0ng/ml). Prevalences of iron deficiency (20%, 20.0% and 17.1% respectively) of postmenopausal women. The mean daily intakes of total iron in pre- and postmenopausal women were 17.5$\pm$9.3mg and 15.6$\pm$6.9mg, respectively. Bioavailabilities of dietary iron were 6.5% and 4.5% in pre- and post-groups. These results indicate that individual dietary guidelines should be used to educate middle-aged women different in status of menopause. For example, premenopausal women should increase nutritional iron status and postmenopausal women should try to prevent obesity.

• Journal of the Korean Magnetics Society
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• v.25 no.5
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• pp.169-173
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• 2015

Fe compounds of volcanic basalt samples distributed at the Hantan riverside in Cheorwon were investigated by means of X-ray diffractometry (XRD), X-ray fluorescence spectroscopy (XRF) and $M{\ddot{o}}ssbauer$ spectroscopy. We found that samples were typical basic rock which consisted of augite, anorthite, albite and sanidine etc. They had the total amount of iron compounds including hematite (${\alpha}-Fe_2O_3$) varies from 6.20 w% to 12.8 w% depending on the different regions by XRF. The $M{\ddot{o}}ssbauer$ spectra of the samples were consisted of three doublets. The balance state of Fe ions of all samples were chiefly $Fe^{2+}$, and $Fe^{2+}/Fe^{3+}$ ratios were 2.27~3.42.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.17-22
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• 2002

A wooden coffin estimated to be made in Baikjae Dynasty in AD. 6 century was excavated from ancient tombs in Nung-san ri, and examined to identify its wood species using light and electron microscopy. Wooden part attached to oxdized complex around the iron nails on the coffin was electro-chemically separated to prepare the samples for observation. The results revealed that 24 samples out of 28 samples investigated were identified as Torreya nucifera, while the rest 4 samples were identified as Pinus densiflora.

• Journal of Conservation Science
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• v.17 s.17
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• pp.57-64
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• 2005

In the course of examining the micro structure of Iron chisel and Iron arrowhead, a relics of the 16th or 17th of Chosun Dynasty unearthed at near Gangsun-tower, Chengpyeong temple. Collected un-eroded samples from the relics were looked into the metallic structure through optical metallography. Non-metallic inclusions were-analysed by SEM and EDS. The micro structure examination and SEM-SDS analysis revealed that Iron chisel and Iron arrowhead had been produced from the sponge iron close to pure iron made by low temperature reducing in a solid and then the surface carbon content was increased by carburizing treatment. It was also found that Iron chisel had been hardened through the repetitive processes of quench hardening and heat treatment, after increasing carbon content to a certain level. Up to now, there have been a number of studies in the domestic academia which were studied mainly on the structure of metallic relics in the period of the Three Kingdoms or before. Although this research was limited in type and number of the relics, it turned out to be interesting in that it revealed the 16th or 17th century way of processing iron, even in fragments. It is thought to be fruitful that iron had been made even in the Chosun Dynasty from the sponge iron.