• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.57.1-57.1
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• 2011

We studied the performance of CdSe nanoparticle in the active layer of organic photovoltaics (OPVs) by changing concentration of the CdSe NPs in the P3HT:PCBM layer. We observed that the absorption peak value gradually increases with the increasing amount of CdSe NPs at 600nm wave length. However, the electrical properties of OPVs correspond less with the tendency of UV/visible result. The highest performance was shown with 10% of CdSe NPs. The device performance decreased after 10% of CdSe NPs, this shows the dependencies of performanc of hybrid solar cells on the CdSe NPs loading amount. The resulting OPVs with 10 % of CdSe NPs show a short circuit current density ($J_{sc}$) of $6.96mA/cm^2$, open circuit voltage ($V_{oc}$) of 0.61V, fill factor (FF) of 0.59, and power conversion efficiency (PCE) of 2.53% under AM 1.5 ($100mW/cm^2$).

• Journal of Radiation Protection and Research
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• v.21 no.1
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• pp.1-7
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• 1996

In this paper, we discussed the fabrication and characterization of bulk type CdZnTe detector for pocket surveymeter. The resistivity of CdZnTe single crystal grown by the High Pressure Bridgman method is in the mid of $10^9$ ohm-cm. The detector structure is Au/CdZnTe/Au and gold electrode is formed by electroless deposition method. Resolutions of 4.8keV and 2.2keV were observed at 22.2keV line of $^{109}Cd$ and 59.6keV line of $^{241}Am$ at room temperature, respectively. We also constructed the small size pocket surveymeter using home made CdZnTe detector. It shows the good linearity over a range from 1mR/hr to 10R/hr with deviation less than 5%. The sensitivity of the surveymeter developed is $2.2{\times}10^3 cps/Rad\;hr^{-1}$ for the 662keV of $^{l37}Cs\;{\gamma}-ray$.

• Journal of the Semiconductor & Display Technology
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• v.4 no.1 s.10
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• pp.29-34
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• 2005

Tungsten oxide($WO_{3}$) is suitable to materials for photochromic window in the visible region. The resistivities of CdS, $WO_{3}$, and $WO_{3}$/CdS films prepared by thermal evaporation method were $4.61\times 10\^{3}$, $7.59\times10^{3}$, and $6.29\times10^{3}$ $\omega$ cm. And x-ray diffraction patterns of CdS, $WO_{3}$/CdS films showed a preferred orientation of hexagonal(002), and the monoclinic(020) structure, respectively. The optical transmission were measured that the cut-on wavelength were 510nm, 380nm for CdS and $WO_{3}$ films respectively, and the transmission spectrum of $WO_{3}$/CdS was shifted into the visible region. Photoluminescence(PL) spectra showed the two peaks at 2.8 eV and 3.2 eV for the as-grown sample($WO_{3}$/CdS ($500{\AA}$), but the other sample($WO_{3}$/CdS ($1000{\AA}$)) had a peak energy value of 2.8 eV. The photochromism of $WO_{3}$/CdS films showed that the excitation of electron-hole pairs and subsequent coloration is shifted into visible-light range. And the spectral behavior of coloration turned out to be proportional to the excited electron-hole pairs creation rate of CdS film. This result is interpreted in terms of charge carrier injection from the CdS-layer into the $WO_{3}$ films. We found a value of about 2.8 eV of $WO_{3}$/CdS film which is somewhat higher than peak energy of 2.54 eV using CBD prepared by Bechinger et. al.

• Electrical & Electronic Materials
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• v.10 no.1
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• pp.39-44
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• 1997

Bulk type radiation detector of Au/Cd$_{1-x}$ Zn$_{x}$Te(x=20%)/Au structure using Cd$_{1-x}$ Zn$_{x}$Te(x=20%) wafer(3x4xl mm$^{3}$) grown by high pressure Bridgman method has been developed. We etched wafer surfaces with 2% Br-methanol solution and coated gold thin film on the surfaces by electroless deposition method for 5 min. in 49/o HAuCI$_{3}$ 4H20 solution. Initial etch rates of Cd, Zn and Te were 46%, 12% and 42% respectively. After etched, the surface of wafer was slightly revealed to Te rich condition. The leakage current was increased with etch time, but it didn't exceed 3nA at 50volt. The thickness of Au film was about 100nm by Rutherford Backscattering Spectroscopy(RBS). The resolution were 6.7% for 22.1 keV photon from 109 $^{109}$ Cd and 8.2% for 59.5 keV photon from $^{241}$ Am. The radiation detector such as Au/Cd$_{1-x}$ Zn$_{x}$Te(x=20%)/Au structure was more effective to monitor the low energy gamma radiation.iation.

• Applied Microscopy
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• v.33 no.1
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• pp.59-78
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• 2003

This research was conducted to determine the effects of chitosanoligosaccharide on liver poisoning induced by cadmium (Cd). Three groups of mice were used in this research. The first group was only injected with cadmium (5.0 mg/kg; i.p.) (group Cd) and the second one with cadmium and chitosanoligosaccharide (0.5% solution) at the same time (group Cd+Chi). The third one which had already been injeted with chitosanoligosaccharide (0.5% Solution) aweek before (group Ch7+Cd) was used. In order to investigate the inhibitory action of chitosanoligosaccharide on liver damage, enzyme activity in serum, glutathione peroxidase (GSHPx) activity and glutathione reductase (GR) activity were relatively measured. In addition, histological observations were made to determine the morphologic injury of liver tissues. As the result of enzyme activity in serum, the activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) in chitosanoligosaccharide-injected groups Cd+Chi and Chi7+Cd was lower than in group Cd. GSH-Px activity was sharply increased in groups Cd+Chi and Chi7+Cd compared to group Cd. GR activity was conspicuously decreased in groups Cd+Chi and Chi7+Cd compared to group Cd. As the result of light microscopic observation, liver cell necrosis caused by cadmium poisoning was obseved in liver cells. The finding of group Cd+Chi and Chi7+Cd was similar total on of normal groups. As the result of electron microscopic observation, mitochondria in group Cd showed a severe swelling phenomenon, RER fragment and ribosome dropout. However, in groups Cd+Chi and Chi7+Cd, mitochondria wiht high electron density were distributed and RER forming a typical lamellae with ribosome was observed. From these results, cadmium toxicity on rat liver tissues could be lessened by chitosanoligosaccharide.

• Journal of Soil and Groundwater Environment
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• v.8 no.2
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• pp.87-91
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• 2003

This study was carried out to investigate the heavy metal distributions of soils in the vicinity of Shi-Hwa industrial complex region, where the air pollutants from industrial area could affect the soil environment of near residential and green areas. The ranges of contents of As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn in soils were 0.58~3.81, ND~0.91, 0.15~6.33, ND~l.86, 0.14~110.27, ND~l.17, 0.04~10.59, 1.16~86.48 and 1.83~212.65 mg/kg, respectively. For all industrial, residential and green areas, the heavy metal contents were much lower than the standard of Korean Soil Environmental Preservation Act or the critical concentration which phytotoxicity is considered to be possible. Mean values of contents of As were similar in industrial, residential and green areas. However, the mean values of contents of Cd and Cr in industrial area were higher 10 and 5 times than those in residential and green area, respectively. And also the mean values of contents of Co, Cu, Hg, Ni, Pb and Zn in industrial area were higher 2~3 times than those in residential and green area.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.656-659
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• 2001

Cyclodextrin glucanotransferase (CGTase) (EC 2.4.1.19) use starch to produce cyclic maltooligosaccharides (cyclodextrins, CDs) which are of interest in various applications. To obtain a novel CGTase having high CD-forming activity, ${\beta}-cyclodextrin$ glucanotransferase $({\beta}-CGTase)$ from Bacillus firmus var. alkalophilus was modified through site-directed mutagenesis and constructed five mutants, H59T, H59Q, Y96M, 9O-PPI-93, and ${\Delta}(148-154)D$, respectively. Y96M and ${\Delta}(148-154)D$ showed much higher level of conversion yields of starch into CDs from 28.6% to about 39% compared to wild-type ${\beta}-CGTase$, respectively, but 90-PPI-93 maintained similar convesion yields of starch to CDs. And their ${\beta}-CD$ ratios to total CDs were not changed and maintained, and convesion yields to linear maltooligosaccharides of all mutants were not changed significantly. These results indicates that five mutations of ${\beta}-CGTase$ from Bacillus firmus var. alkalophilus appears to be important roles for increase of overall CD production rather than change of its product specificity, especially.

• YAKHAK HOEJI
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• v.59 no.1
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• pp.1-5
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• 2015

Cordyceps militaris has shown to have various pharmacological activities including an immune-modulatory effect. Previously, we reported that anti-influenza effect of C. militaris in DBA/2 mice was mediated by increased IL-12 and the activation of NK cells. In this study, we investigated the effect of C. militaris on adaptive immune responses using DBA2 mice immunized with influenza vaccine. To determine the effect of C. militaris on antigen presentation capability, we treated RAW 264.7 cells with various concentrations of ethanol extract of C. militaris, which showed a significant upregulation of CD86 (B7.2), CD284 (TLR4), CD40, H-2k (MHC I) and I-Ad (MHC II). To examine the direct effect of C. militaris on adaptive immune responses, we immunized DBA2 mice with influenza vaccine in presence or absence of C. militaris. After 2 or 4 weeks, influenza-specific T cell proliferation, HAI titers and IFN-${\gamma}$ production were measured in plasma or PBMCs isolated from animals. Influenza-specific T cell proliferation and HAI titers were not considerably increased in immunized mice in presence of C. militaris. However, the production of IFN-${\gamma}$ was much greater in immunized mice with C. militaris as adjuvant than only immunized mice.

• The Korean Journal of Ecology
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• v.25 no.6
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• pp.379-382
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• 2002

The present study was to investigate Pb and Cd concentrations in tissues of feral pigeons in urban areas. The Pb levels in bones and livers did not differ between Seoul and Kwangju areas. However, there were significant differences in kidney and liver Cd concentrations between the study sites. These are thought to be a reflection of the metal exposure conditions in the local environment. In particular, metal levels from Seoul were compared with those obtained in the same area between 1991 and 2000 in terms of the long-term biomonitoring approaches. The mean Pb concentrations in bones decreased from 59.1 $\mu$g/wet g in 1991 to 29.5 $\mu$g/wet g in 2000, totaling a reduction in concentrations of approximately 50 percent. However, there were no significant differences in the liver Pb concentrations. Concentrations of Cd in livers and kidneys did not differ between 1991 and 2000.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.446-452
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• 2000

This study was carried out to investigate the effect of mine activity on paddy fields, agricultural water, and plants in the ruined Oksung Cu-Zn mine area. Soil samples collected from paddy fields adjacent to the Cu-Zn mine sites were sequentially extracted and determined the contents of heavy metals such as Cd, Zn, Cu, Pb, Cr and Ni. Distribution of exchangeable heavy metals in soils was 30.2% of Cd, 11.3% of Zn, 2.2% of Cu, 4.6% of Cr, 0.6% of Pb and 3.9% of Ni. Water soluble heavy metals were only detected with Zn. The contents of heavy metals in water collected from the mine were 0.01 of Cd, 27.35 of Zn, 4.86 of Cu, 1.04 of Pb, 0.03 of Cr and $0.08mg\;L^{-1}$ of Ni. while the contents in waler collected out of the mine were 16.67 of Zn, 0.59 of Cu, 0.49 of Pb, 0.05 of Cr and $0.06mg\;L^{-1}$ of Ni. On the other hand, agricultural water near mine area were 1.26 of Zn, 0.05 of Cu, 0.05 of Pb and $0.02mg\;L^{-1}$ of Ni. Both Cd and Cr were not detected in the agricultural water.