• Journal of the Korean Chemical Society
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• v.15 no.6
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• pp.347-352
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• 1971

The variations of the positive and negative electrode potentials, and of internal pressure were measured during the charge of the sealed type Ni-Cd cell. Both polarization characteristics of a paste type Cd-electrode as a gas diffusion electrode in 30% KOH solution and the effects of active carbon electrode as an oxygen consuming auxiliary electrode of the Ni-Cd cell on the charging characteristics of the cell were studied. Peak voltage at the end of charge of the cell is ascribed to the peak at the negative electrode potential, which is due to the concentration polarization by the lack of $Cd^{++}$ ion and oxygen concentration. And the recovery of the negative electrode potential is resulted from depolarization by the increasing diffusion limiting current density with the increasing oxygen pressure. The active carbon electrode was effective as an oxygen consuming auxiliary electrode. The internal pressure of the cell could be maintained below 200mmHg even at one hour rate charge and overcharge by the use of active carbon electrode as an auxiliary electrode.

• Polymer(Korea)
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• v.30 no.3
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• pp.266-270
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• 2006

Poly [(dimethylmethylyinyl) siloxane] phosphineoxide (PMViSPO) was prepared by adding phosphorus oxychloride $(POCl_3)$ to poly (dimethylmethylyinyl) siloxane (PMViS) at $0^{\circ}C$ under nitrogen atmosphere. Cadmium selenide (CdSe) was prepared by reacting cadmium oxide (CdO), tetradecyl-phosphonic acid (TDPA), trioctylphosphine oxide (TOPO) at $300^{\circ}C$, and adding solution of dissolved Se to tributylphosphine (TBP) and trioctylphosphine (TOP) CdSe-poly [(dimethylmethylvinyl) siloxane] phosphine-oxide (CdSe-SPO) adduct was synthesised by adding PMViSPO to CdSe solution. Liquid silicone rubber composite (LSRC-1) was prepared by compounding $\alpha,\omega-vinyl$ poly (dimethylsiloxane) (VPMS), $\alpha,\omega-hydrogen$) poly(dimethylsiloxane) (HPMS), and CdSe under Pt catalyst, and also LSRC-2 was prepared from VPMS, HPMS, and CdSe-SPO using Pt catalyst. It was confirmed that CdSe nanoparticles with photoluminescence characteristics was dispersed uniformly in LSR matrix. The diameter of CdSe was $30\sim50nm$. By measuring the number of CdSe nanoparticles, 202 particles of CdSe in LSRC-2 and 165 particles of CdSe in LSRC-1 were dispersed in the same area of LSR matrix. Thermal stability for LSRC-2 compounded with CdSe-SPO was better than LSRC-1.

• Journal of the Korea Institute of Military Science and Technology
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• v.1 no.1
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• pp.227-237
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• 1998

HgCdTe Is the most versatile material for the developing infrared devices. Not like III-V compound semiconductors or silicon-based photo-detecting materials, HgCdTe has unique characteristics such as adjustable bandgap, very high electron mobility, and large difference between electron and hole mobilities. Many research groups have been interested in this material since early 70's, but mainly due to its thermodynamic difficulties for preparing materials, no single growth technique is appreciated as a standard growth technique in this research field. Solid state recrystallization(SSR), travelling heater method(THM), and Bridgman growth are major techniques used to grow bulk HgCdTe material. Materials with high quality and purity can be grown using these bulk growth techniques, however, due to the large separation between solidus and liquidus line on the phase diagram, it is very difficult to grow large materials with minimun defects. Various epitaxial growth techniques were adopted to get large area HgCdTe and among them liquid phase epitaxy(LPE), metal organic chemical vapor deposition(MOCVD), and molecular beam epitaxy(MBE) are most frequently used techniques. There are also various types of photo-detectors utilizing HgCdTe materials, and photovoltaic and photoconductive devices are most interested types of detectors up to these days. For the larger may detectors, photovoltaic devices have some advantages over power-requiring photoconductive devices. In this paper we reported the main results on the HgCdTe growing and characterization including LPE and MOCVD, device fabrication and its characteristics such as single element and linear array($8{\times}1$ PC, $128{\times}1$ PV and 4120{\times}1$ PC). Also we included the results of the dewar manufacturing, assembling, and optical and environmental test of the detectors.

• Electrical & Electronic Materials
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• v.8 no.4
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• pp.406-412
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• 1995

A n-CdS thin films were evaporated by thermal evaporation method and their structure, optical transmission spectra and electrical characteristics were investigated. The photovoltaic characteristics of solar cells which were fabricated in optimum conditions measured. The evaporated CdS thin films showed in hexagonal structure and above 80% of optical transmission spectra regardless of impurity doping. The high quality thin films could be obtained at 150.deg. C temperature of substrate, which is useful for solar cell window layer with low resistivity of 6*10$\^$-2/(.ohm.-cm) by In doping We measured the electrical and optical characteristics of the n-CdS/p-InP heterojunction solar cells. The most efficient photovoltaic characteristics of heterojunction solar cells had the open circuit voltage of 0.66V, short circuit current density of 13.85mA/cm$\^$2/, fill factor of 0.576 and conversion efficiency of 8.78% under 60mW/cm$\^$2/ illumination.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.316-322
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• 2006

Objective of this research was to assess the release characteristics of metals from the mine tailing to base the prediction of metal load potential from tailing to soils. Water-soluble concentrations of Cd, Cu, Pb and Zn released from mine tailing after 2 hrs were 2.31, 129.38, 17.17, and 287.53 mg/kg, respectively, as compared to 1.6, 128, 108, and 142 mg/kg that were extractable by 0.1 M HCl. Kinetics of metal releases followed the power function model significantly indicating that more of water soluble fractions of those metals released at the initial short time, followed by a slow increase. Concentrations of metals released from tailing by water and 0.1 M HCl were in the orders of Zn > Cu > Pb > Cd. The breakthrough curve from the column experiment showed that concentrations of Cd, Cu, and Zn reached at highest after one pore volume, but that of Pb reached highest after five pore volumes when 0.1 M HCl was used as eluent. The release rate of Cd from mine tailing was the fastest but Pb was the slowest. The cumulative mass of metal released by 0.1 M HCl was in the order of Zn > Cu > Pb > Cd after nine pore volume elution.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.266-272
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• 2013

Objectives: This study aimed to evaluate the effects of low-level exposure to toluene on T lymphocytes subpopulations.s. Methods: The study lasted from April to October 2010. The subjects were 390 male workers, among whom 137 were chronically exposed to toluene in video-tape manufacturing factories and 253 were controls had never been occupationally exposed to hazardous chemicals. The subpoupulations of CD4+, CD8+, CD16+ (natural killer cells) and total (CD3+) T lymphocytes were examined by two-color staining using monoclonal antibodies. The general and job characteristics of subjects were assessed through a self-administered questionnaire. Results: There was no significant difference in general and job characteristics between both groups. No significant difference in lipid peroxide level was observed between the control and exposed workers, but the concentration of hydrogen peroxide was significantly higher in the exposed workers. The numbers of CD16+ T lymphocytes in controls were significantly higher than those in exposed workers, but no significant differences were found in CD4+, CD8+ and CD3+ T lymphocytes. Hydrogen peroxide levels showed a significantly negative correlation with CD8+ (r = -0.29, p < 0.01), CD16+ (r = -0.56, p < 0.01) and CD3+(r = -0.22. p < 0.01), and toluene levels was significantly negative correlated with CD3+ (r = -0.29, p < 0.05). Conclusions: Our results suggest that chronic low-level exposure to toluene affects cell-mediated immunity and the effects might mediate through ROSs (Reactive Oxygen Species) such as hydrogen peroxide.

• Analytical Science and Technology
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• v.13 no.3
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• pp.368-377
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• 2000

Si-immobilized Sargassum horneri was used to study the adsorption characteristics along with maximum adsorption conditions of heavy metal ions, Cd(II) and Ph(II) on the Si-immobilized Sargassum horneri. More amount of Cd(II) and Pb(II) ions on the Si-immobilized Sargassum horneri than Sargassum horneri were adsorbed. And Pb(II) ions were more adsorbed in all algae than Cd(II) ions more effectively in alkaline than in acidity. Recovery ratios of Cd(II) and Pb(II) ions on the Sargassum horneri were 58.0-62.6%, 61.2-64.4% respectively, Si-immobilized Sargassum horneri 56.8-92.7%, 37.8-47.9%. Recovery ratio of Cd(II) ion was higher on the Si-immobilized Sargassum horneri but it of Pb(II) ion was lower on the Si-immobilized Sargassum horneri.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.4
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• pp.502-506
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• 2012

In order to find the structural characteristics of the thin films of group II-VI semiconductor compounds compared with those of powder materials, films were made of 4 powders of ZnS, CdS, CdSe, and CdTe(Aldrich), each with 99.99 % purity. For the ZnS/CdS multi-layers, the ZnS layer was coated over the CdS layer on an $AlO_x$ membrane, which served as a protective layer within a vacuum at the average speed of 1 ${\AA}$/sec. After studying the structures of the group II-VI semiconductor thin films by using X-ray spectroscopy, we found that the ZnS, ZnS/CdS, CdS, and CdSe films were hexagonal and exhibited some degree of preferred orientation. Also, the particles of the thin films of II-VI semiconductor compounds proved to be more homogeneous in size compared to those of the powder materials. These results were further verified through scanning electron microscopy(SEM), EDX analysis, and powder and thin film X-ray diffraction.

• Journal of Environmental Health Sciences
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• v.17 no.1
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• pp.79-88
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• 1991

These studies were carried out to find out some characteristic responses of biological samples under the exposure of trace metals. In animal experiment, six rats per week were killed for 6 weeks under Cd exposures and the concentrations of Cd, Cu and Zn in their organs and blood were determined by flame atomic absorption spectrophotometry.The results were summarized as follows: In animal experiments, the concentrations of Cd in the liver and kidney of Cd exposure groups were increased, however, the values of hematocrit and hemoglobin in blood were decreased remarkably. The body weight of the Cd exposure groups showed lower trend than that of control group. The concentrations of Cd in heart, lung and testes were increased slowly during the first 2 weeks. The concentrations of Cd in their organs decreased while the rapid increase of the concentration of Cd in the liver and kidney was observed. While rapid increase of the concentra~ion of Cd in the liver and kidney was observed, the concentrations of Cd in the organs were decreased afterward and increased again while the low increase of the concentration of Cd in the liver and kidney was observed. The concentrations Cu and Zn were increased remarkably in all the organs for first 2 and 3 weeks. In the exposure groups of Cd+Cu and Cd+Zn, the liver and kidney didn't show lower concentration of Cd than that of Cd group.

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.4
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• pp.43-48
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• 1981

The Cdse TFTs with SiO gate insulator layer have been fabricated with vacum evaporatim technique. The effects of semiconductor thickness and drain-source channel length on the electrical propertis have been investigated. The TFTs with 1000$\AA$ SiO insulator, 1500 $\AA$ CdSe semiconductor layer and 40$\mu$m chammel length showed the best characteristics.