• Construction Engineering and Management
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• v.15 no.5
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• pp.19-22
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• 2014

• The Journal of the Petrological Society of Korea
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• v.10 no.2
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• pp.95-105
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• 2001

U-Pb age determination was performed on the zircon fractions separated from the metamorphic rocks of three locations of the Gyeonggi Massif. The ages obtained from the upper and lower intersections between concordia curve and discordia lines made of the zircon fractions separated from the rocks of each locality we: $2168\pm$24 Ma and $1227\pm$40 Ma for the Yongduri Gneiss Complex, $1955\pm$22 Ma and $493\pm$32 Ma for the Euiam Group, and $3712\pm$244 Ma and $1613\pm$51 Ma for the Yongmunsan Group (2$\sigma$ errors). The upper intercept ages from the Yongduri Gneiss Complex and the Euiam Group of Gyeonggi massif are very similar to those obtained from the granitic gneisses and the porphyroblastic gneisses of Yeongnam massif respectively. Such similarities suggest that Gyeonggi and Yeongnam massifs might situate under the similar tectonic and geographic environment during ca. 2.2-1.9 Ga. The upper intercept age of Youngmunsan Formation (3.7 Ga) shows large error, because most of the zircon fractions are plotted very close to the lower intersection. It is necessary to investigate further to confirm this age. However, It may suggest the possibility of occurrence of the oldest crust of the northeast Asia similar to the one reported recently from the northeast China. The lower intercept age of the Yongmunsan Group is interpreted to indicate strong metamorphism. Such age postdates the 1.85-1.7 Ga metamorphism and igneous activities occurred in the Yeongnam massif, which might record the late Paleoproterozoic tectonic activities simultaneously occurred in both massifs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.716-723
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• 1993

This study was carried out to estimate intake level of Pb, Fe, Cu in rural area of Korea(12 males and 18 females). Analyses for the nutritional status of the record, duplicated diet collections, 24-hour urine collections, and venous blood sampling before measuring of blood pressure. The mean age and blood pressure of the subjects were 45.8$\pm$11.1years and 117.5$\pm$22.2/80.8$\pm$15.6mmHe in males, and 41.9$\pm$11.0years, 110.0$\pm$ 11.9/73.9$\pm$8.5mmHg in females, respectively. In respect to both males and females, mean BMI were 22.0$\pm$2.3, 23.1$\pm$3.0, mean Rohrer index were 131.8$\pm$14.8, 142.4$\pm$20.2 and mean skinfold thickness were 12.4$\pm$5.9mm, 25.3$\pm$7.4mm, respectively. The daily mean intakes of Pb, Fe, and Cu estimated for 3 days were 277.2$\pm$111.2$\mu\textrm{g}$/day, 12.7$\mu\textrm{g}$ 7.6mg/day, and 3.0$\pm$1.4mg/day in males and 192.0$\pm$72.4$\mu\textrm{g}$/day, 13.3$\pm$5.8mg/day, and 3.7 $\pm$1.7mg/day in females, respectively. The mean concentrations of serum Pb, Fe, Cu were 11.0$\pm$2.0$\mu\textrm{g}$/dl, 131.1$\pm$42.6$\mu\textrm{g}$/dl, 120.3$\pm$25.7$\mu\textrm{g}$/dl in males and 9.0$\pm$1.2$\mu\textrm{g}$/dl, 112.2$\pm$ 35.9$\mu\textrm{g}$/dl, 117.3$\pm$17.9$\mu\textrm{g}$/dl in females, respectively. The mean levels of Hb and Hct were 15.1$\pm$1.1g/dl, 45.2$\pm$3.3% in males and 13.1$\pm$0.8g/dl, 39.8$\pm$2.6% in females, respectively. The 24-hour urinary excretions of Pb, Fe, Cu were 35.5$\pm$10.0$\mu\textrm{g}$/day, 0.16$\pm$0.12mg/day, 60.12$\pm$0.02$\mu\textrm{g}$/day in males, and 25.3$\pm$11.0$\mu\textrm{g}$/day, 0.24$\pm$0.20mg/day, 70.07$\pm$0.03$\mu\textrm{g}$/day in females, respectively. In conclusion, the Pb intake in self selected diet of this subjects was not in the level that antagonized to Fe and Cu metabolism seriously.

• Korean Journal of Environmental Agriculture
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• v.5 no.1
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• pp.11-23
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• 1986

Soils and rice plants in wastewater irrigated area of the Mangyeong River receiving waster from the Jeonju Industrial Complex and municipal sewage were sampled at two depths to assess the nature and content of Cd, Cu, Pb and Zn, particularly with respect to distance from wastewater source. For metal levels of soils in these area, no difference in the heavy metal contents between the surface and the subsurface soils was found. Total contents of Cu, Pb and Zn in soils were negatively correlated with distance from the source. A positive correlation was found between contents of total and 0.1N-HCl extractable or $1N-CH_3COONH_4$ extractable heavy metals in surface soils of these area. Total contents of heavy metals in soils were positively correlated with clay, soil organic matter and cation exchange capacity. Heavy metal contents of brown rice sampled at the Jeon-ju Industrial Complex area ranged from 0.15 to 0.91 ppm for Cd, from 1.13 to 5.68 ppm for Cu, from 0.22 to 7.16 ppm for Pb and from 11.74 to 38.66 ppm for Zn. Negative correlation was found between the contents of Cd, Cu, Pb, and Zn in the brown rice and the distance from the source. The contents of Cd, Cu and Zn in rice straw were positively correlated with those in the brown rice.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.1
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• pp.17-22
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• 2003

The experimental FT-IR spectra and DTA curves of the $PbO-Bi_2O_3-B_2O_3-SiO_2$ glasses have been investigated. The composition ratio dependence of glass transition temperature showed that the structure of this glass system changes at 60 mol% $Bi_2O_3$. We have observed that the FT-IR spectra of the investigated samples with high bismuth content are dominated by bands associated to the structural units of the heaviest cation, $Bi^{3+}$ and the boron atoms in the treated samples are three and four coordinated even for very high $Bi_2O_3$ content. The low intensity of these non-bridging oxygen bands, for high PbO content glasses, can be attributed to the strong network-forming roles of PbO. The glasses absorption bands exhibited a greater change in intensities on crystallization.

• Resources Recycling
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• v.13 no.1
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• pp.22-27
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• 2004

Purification on the leaching solution of the crude zinc oxide obtained by the reduction of EAF dust has been carried out. Pb and Cd ions in the leaching solution were precipitated and removed from the solution by the addition of zinc metal powder. The purification condition for electrowinning to obtain the high purity zinc metal was investigated by analyzing the effects of Pb and Cd ion concentrations on the contents of impurities in the recovered zinc metal. The 3 N purity zinc metal was obtained at the electrolysis condition of the concentrations of Pb less than 2 ppm and Cd less than 0.1 ppm in the purified solution. For this purification, the amounts of zinc metal powder more than 8.5 g/l should be added in the crude zinc oxide leached solution.

• Journal of Food Hygiene and Safety
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• v.22 no.1
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• pp.52-56
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• 2007

In order to offer monitoring data about standard and specification of metallic kitchenware, we carried out the material test and migration test of lead and antimony in 71 kinds of kitchenwares. As a result of this study, Pb was detected less than 0.06% at the material test and Sb was not defected in 71 kinds of kitchenwares. Pb was also detected less than 0.41 mg/L at the migration test. Currently according to the Food Code of Korea, Pb and Sb in metal product shall not exceed 10% and 5%, respectively and Pb migrated from metal product shall not exceed 1.0 mg/L. Therefore, our all data are not exceeding the standard and specification of metal product and show that all the kitchenwares in domestic circulation may be safe.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.2
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• pp.117-121
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• 2018

Perovskite solar cells have received increasing attention in recent years because of their outstanding power conversion efficiency (exceeding 22%). However, they typically contain toxic Pb, which is a limiting factor for industrialization. We focused on preparing Pb-free perovskite films of Ag-Bi-I trivalent compounds. Perovskite thin films with improved optical properties were obtained by applying an anti-solvent (toluene) washing technique during the spin coating of perovskites. In addition, the surface condition of the perovskite film was optimized using a multi-step thermal annealing treatment. Using the optimized process parameters, $AgBi_2I_7$ perovskite films with good absorption and improved planar surface topography (root mean square roughness decreased from 80 to 26 nm) were obtained. This study is expected to open up new possibilities for the development of high performance $AgBi_2I_7$ perovskite solar cells for applications in Pb-free energy conversion devices.

• Journal of Plant Biology
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• v.22 no.1_2
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• pp.15-20
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• 1979

The present study was carried out to investigate the effects of cadmium(Cd), mercury(Hg) and lead(Pb) on the respiration of the germinating seeds. Two kinds of seeds namely, mungbean (Paseolus radiatus L.) and buckwheat (Fagopyrum esculentum M ench) were used for the plant materials. The concentrations of Cd, Hg, and Pb applied for the treatment were 0.1, 1, 10, 100 and 1,000ppm. The germination test was carried out in the dark at 27$^{\circ}C$. Regardless of the kinds of heavy metals, the respiration of the germinating seeds was greatly increased for 24hrs absorbing the heavy metals, and subsequently the respiration was increased average 0.69mg/g.hr.CO2 for mungbean and 0.7mg/g.hr.CO2 for buckwheat. In the lower concentrations of cadmium and lead than 10ppm the germinating rates, seedling concentraitons. The germinating rates, the seedling growth and the respiration were not increased in ay concentrations of mercury, but were decreased with increase of the mercury concenration. The inhibition of seeds respiration by mercury was 3 times higher than by cadmium, and 5 times higher than that by lead. The toxicity of three heavy metals on the respiration was showed from the highest to the lowest in the order of Hg, Cd, and Pb.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1806-1810
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• 2008

Thirty five AD patients were treated with Phellinus linteus grown in germinated brown rice(PB) p.o., at 6, 9, and 12 g/day to the patients with their body weight for 12 weeks. A significant reduction in mean severity scores and mean symptom scores was observed after PB treatment. The mean SCORAD indices pre and post PB treatment were $31.28{\pm}10.01$ and $22.39{\pm}15.59$ (p<0.05), respectively. And the mean symptom score of pruritus assessment decreased from $7.37{\pm}1.33$ to $4.6{\pm}2.34$ (p<0.05) after PB treatment. These results suggest that PB shows alleviation of atopic dermatitis symptoms.