• Bulletin of the Korean Chemical Society
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• v.23 no.8
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• pp.1121-1126
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• 2002

Two anhydrous crystal structures of fully dehydrated Cd2+ - and Cs+ -exchanged zeolite X, Cd32Cs28Si100Al92O384 (Cd32Cs28-X: a = 24.828(11) $\AA)$ and fully dehydrated Cd,sup>2+ - and Rb+ -exchanged zeolite X, Cd28Rb36Si100Al92O384 (Cd28Rb36-X: a = 24.794(2) $\AA$), have been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at $21(1)^{\circ}C.$ The structures were refined to the final error indices, R1 = 0.058 and R2 = 0.065 with 637 reflections for Cd32Cs28-X and R1 = 0.086 and R2 = 0.113 with 521 reflections for Cd28Rb36-X for which I > $3\sigma(I)$. In the structure of Cd,sub>32Cs28-X, 16 Cd2+ ions fill the octahedral sites I at the centers of the double six rings (Cd-O = $2.358(8)\AA$ and O-Cd-O = $90.8(3)^{\circ}$ ). The remaining 16 Cd2+ ions occupy site II (Cd-O = $2.194(8)\AA$ and O-Cd-O = $119.7(4)^{\circ})$ and six Cs+ ions occupy site II opposite to the single six-rings in the supercage; each is $2.322\AA$ from the plane of three oxygens (Cs-O = 3.193(13) and O-Cs-O = $73.0(2)^{\circ}).$ Aboutten Cs+ ions are found at site II', $1.974\AA$ into the sodalite cavity from their three oxygen plane (Cs-O = $2.947(8)\AA$ and O-Cs-O = $80.2(3)^{\circ}).$ The remaining 12 Cs+ ions are distributed over site III' (Cs-O = 3.143(9) and O-Cs-O= $59.1(2)^{\circ})$. In the structure of Cd28Rb36-X, 16 Cd2+ ions fill the octahedral sites I at the center of the double-sixrings (Cd-O = 2.349(15) and O-Cd-O = $91.3(5)^{\circ}$ ). Another 12 Cd2+ ions occupy two different II sites (Cd-O = $2.171(18)/2.269(17)\AA$ and O-Cd-O = $119.7(7)/113.2(7)^{\circ}).$ Fifteen Rb+ ions occupy site II (Rb-O = $2.707(17)\AA$ and O-Rb-O = $87.8(5)^{\circ}).$ The remaining 21 Rb+ ions are distributed over site III' (Rb-O = $3.001(16)\AA$ and O-Rb-O = $60.7(4)^{\circ})$. It appears that the smaller and more highly charged Cd2+ ions prefer sites I and Ⅱ in that order, and the larger Rb+ and Cs+ ions, which are less able to balance the anionic charge of the zeolite framework, occupy sites II and II' with the remainder going to the least suitable site in the structure, site III'.The maximum Cs+ and Rb+ ion exchanges were 30% and 39%, respectively. Because these cations are too largeto enter the small cavities and their charge distributions may be unfavorable, cation-sieve effects might appear.

• Economic and Environmental Geology
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• v.39 no.2 s.177
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• pp.103-109
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• 2006

Batch adsorption experiments were performed to adsorb cadmium [Cd(II)], copper [Cu(II)], and lead [Pb(II)] onto sphagnum peat moss. According to the results, 10-50 mg/L of Cd(II), Cu(II), and Pb(II) were effectively adsorbed and removed within 1 h by 1.0 g/L of sphagnum peat moss. The amounts of Cd(II), Cu(II), and Pb(II) adsorbed on sphagnum peat moss increased with increasing the initial concentrations. The kinetics for the adsorption of Cd(II), Cu(II), and Pb(II) on sphagnum peat moss was described well using the pseudo-second order model at different initial concentrations. The maximum adsorption capacities calculated from the Langmuir isotherm for Cd(II), Cu(II), and Pb(III) were 33.90, 29.15, and 91.74 mg/g, respectively. Experimental results showed that sphagnum peat moss was a very effective adsorbent on the adsorption of Cd(II), Cu(II), and Pb(II).

• The Korean Journal of Ecology
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• v.27 no.3
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• pp.141-146
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• 2004

This paper reports on Pb and Cd concentrations in the tissues of 76 individuals of 16 rare bird species found dead across Korea. In most of species, Pb concentration was higher in kidney and bone than in liver. The range of the mean liver Pb was 0.47 (Cygnus cygnus)∼3.74 ㎍/wet g (Asio flammeus). Based on hepatic Pb concentrations, 39 (51.3%) of the 76 individuals were classifed as background level (〈2㎍/wet g), 35 (46.1%) were elevated level (〉2㎍/wet g) and 2 (2.6%) were poisoned level (〉10㎍/wet g). These results were indicated many rare birds were suffered from chronic Pb exposure. Cd concentration was generally higher in kidney than in liver and bone. The range of the mean kidney Cd was 0.06 (Bubo bubo)∼l.75㎍/wet g (falco subbuteo). Only one of the 76 individuals had elevated Cd concentration (〉2.7㎍/wet g) in kidney. These results indicated most of rare birds had low Cd accumulations.

• Journal of Microbiology
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• v.39 no.3
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• pp.181-185
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• 2001

The morphological characteristics of newly isolated Cordyceps hepialidicola were characterized, and the phylogenetic relationships with other Cordyceps species were investigated using a sequence analysis of the internal transcribed spacer (ITS). The PCR product of 592 bp showed a homology of 92 and 91% with C. militaris and C. nutans, respectively, In an in vitro model using mouse peripheral blood mononuclear cells (PBMC), a methanol extract of C. hepialidicola induced multiple cytokines, including IFN-${\gamma}$ IL-4, and IL-18. The extract also enhanced the percentages of the CD4$\^$+/ and CD8$\sub$+/ T cells in the healthy murine PBMCs to 56.1% and 13.0%,respectively. The percentages of CD4$\^$+/ and CD8$\^$+/ in the untreated controls were 28.4 and 7.3%, and concanavalin A-treated positive controls were 62.4 and 18.3%, respectively.

• Korean Journal of Environmental Biology
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• v.18 no.2
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• pp.269-277
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• 2000

When Persicaria thunbergii and Rumex crispus were treated with Cd($NO_3$)$_2$ and Pb($NO_3$)$_2$ of 5 or 10 mM for 5 days, the amount of bioaccumulation of $Pb^{2+}$ in the leaf of P. thunbergii was 2.87-8.08$\mu\textrm{g}$/g and that of $Cd^{2+}$ was 0.82-2.79$\mu\textrm{g}$/g. In the case of P. thunbergii, the concentration of $Pb^{2+}$ in the leaf was higher than that of $Cd^{2+}$. On the other hand, in R. crispus, the concentration of $Cd^{2+}$ and $Pb^{2+}$ were similar as follows ; 1.49$\mu\textrm{g}$/g in $Cd^{2+}$ 5mM, 2.90$\mu\textrm{g}$/g in Cd2+ 10mM, 1.83$\mu\textrm{g}$/g in $Pb^{2+}$ 5mM and 2.73$\mu\textrm{g}$/g in $Pb^{2+}$ 10mM. The remaining rate of heavy metals and the variation of pH in the cultured soil decreased as compared with control (100 % and pH 6.48) after 5 days as follows; to 77.l% and pH 6.39 in $Cd^{2+}$ 5mM, 90.2% and pH 5.79 in $Cd^{2+}$ 10 mM, 81.1% and pH 6.00 in $Pb^{2+}$ 5mM, and 85.7% and pH 5.80 in $Pb^{2+}$ 10 mM. The result of size exclusion chromatography, several phytochelatins were seperated from the extract of the leaf of both plants treated with heavy metals. The molecular mass of these phytochelatins were estimated as follows; in the case of P. thunbergii, about 4,300-8,600 da by $Cd^{2+}$ and about 3,200-9,700 da by $Pb^{2+}$, and in R. crispus, about 4,300 da by $Cd^{2+}$ and about 3,200-7,500 da by $Pb^{2+}$. In addition, $A_{254}$ of these phytochelatins were higher than $A_{280}$. [Phytochelatin, Persicaria thunbergii, Rumex crispus]

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.12
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• pp.1016-1021
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• 2002

Luminescent characteristics of FLs were studied according to the structure of electrode for LCD backlight applications. The luminance and luminous efficiency of the FLs fabricated under same conditions were measured and evaluated as functions of magnitude of applied voltage and widths of external electrode. The luminance and luminous efficiency of CCFL at 12 V were 27600 cd/$m^2$ and 35.3 lm/w, respectively The luminance of EEFLS increased as the widths of external electrode increased, and the luminous efficiency of EEFLS showed to increase to 20 mm of electrode width) and to decrease at wider than 20 m of electrode widths. The luminance and luminous efficiency of EEFL with 20 mm of electrode widths were 21600 cd/$m^2$ and 26500 cd/$m^2$, 35.6 lm/w and 34.8 lm/w at 12 V, 14 V, respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.54.1-54.1
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• 2011

The conventional energy-production system by burning fossil fuels releases many pollutants and carbon dioxide($CO_2$) to the environment. Therefore, many countries pay attention to new and renewable energy and invest in the development of these new technologies for the future energy security. One of the most promising of these technologies is a photovoltaic system. In this study, Life Cycle Assessment(LCA) is carried out to analyse the environmental issues(e.g. global warming, abiotic resource depletion) of CdTe photovoltaic system. The spatial and temporal scope of this study was set in Korea during 2004~2005. We assumed that CdTe photovoltaic system was installed in Mokpo where the amount of solar irradiation was higher than other places in Korea. Based on the present data and some assumptions, greenhouse gas emission was 39.2g $CO_2$-eq./kWh. Therefore the electricity produced by CdTe photovoltaic system is more environmentally friendly than the conventional power generation system.

• Journal of Preventive Medicine and Public Health
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• v.14 no.1
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• pp.111-116
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• 1981

Economic development of Korea brought rapid progress and expansion of her industries. Accordingly, number of workers who have been exposed to hazardous metals are increasing. For better understanding the significance of on the job human metal pollution, a total of 22 solderers among autoworkers and 28 controls among medical students was purposively selected as samples of the study. From their blood, concentrations of cadmium and lead were measured with atomic absorption spectrophotometer, and to compare with statistical indices of controls those of solderers were sumarized as follows. 1. Each frequency distribution of cadmium and lead concentration in blood of solderers was more positively skewed showing non-Gausian distribution. 2. Interindividual variation of lead concentration in blood of solderers was markedly revealed. 3. Each mean of cadmium and lead concentration in blood of solderers was higher than that of controls(Cd;p<0.01, Pb;p<0.01). 4. Relative ratio of cadmium concentration in blood of solderers to that of controls was 1.36 by arithmatic mean and 1.39 by geometric mean. Relative ratio of lead concentration in blood of solderers to that of controls was 1.53 by arithmatic mean and 1.30 by geometric mean. 5. It was shown that concentration of lead is slightly correlated with that of cadmium both in solderers and controls(solderers; p<0.1, controls;p<0.1).

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.4
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• pp.336-347
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• 1985

Soils and rice plants subject to smoke from the Jang-hang Smelter were samples at two depths to assess the nature and extend of Cd, Cu, Pb, and Zn contamination, particularly with respect to distance from pollution source. Soils at east site within 1km of the center of the smelter were highly contaminated with Cd, Cu, Pb, and Zn. Metal levels in the smoke-polluted area were higher in surface soil than in subsurface soil, and decreased rapidly with distance reaching nearly background levels at 5km from pollution source. A position correlation was found between contents of total and 0.1 N HCl-extractable, or 1.0N $CH_3COONH_4$- extractable heavy metals in surface soils of pollution. Contents of heavy metals in soils were positively correlated with soil organic matter and cation exchange capacity. The contents of heavy metals in brown rice collected from the paddy field around the Jang-hang Smelter were in the range of 0.23-1.33 ppm for Cd, 2.39-6.25 for Cu, 0.95-8.32 ppm for Pb and 14.60-27.31 for Zn. The contents of Cd, Cu, and Zn in rice straw were positively correlated with those in the brown rice. Negative correlation was found between the contents of Cd, Cu, Pb, and Zn in brown rice and the distance from the source.

• Journal of Preventive Medicine and Public Health
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• v.35 no.4
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• pp.287-294
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• 2002

Objectives : To examine whether cumulative chronic stress influences the immune status, and to verify the effect of social support on the relationship between these two dimensions in male manufacturing workers. Methods : A total of 39 workers were recruited for this study. A structured-questionnaire was used to assess general characteristics, job characteristics (work demand and decision latitude), psychosocial distress, and social support. The serum levels of CD4 and CD8 were measured as immune markers, and were collected between 8:00 and 10:00am in order to standardize the markers. Nonparametric statistics were used to estimate the differences between job characteristics and the immune markers. Results : General characteristics, and health-related behaviors, were not associated with CD4, CD8 or CD4/CD8. No relationships were found between job characteristics and the mean levels of immune reactivity. These results were consistent, even after controlling for social support. Social support failed to modify the relationship toward work demand, decision latitude or psychosocial distress to CD4, CD8, and CD4/CD8. Conclusion : Cumulative chronic life stress might not influence the immune status, and the effects of social support on the immune function under chronic stress, may not play a crucial role in modifying the relationships. This implication supports that the effect of stress on the immune function may be determined by the characteristics of that stress. further research should effectively considers the type, magnitude and timing of a stress event, and modifiable factors, such as personality traits, coping style, and hormone excretion levels, on the alteration of immune status.