• Journal of the Korean Ceramic Society
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• v.40 no.5
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• pp.423-427
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• 2003

Effect of the thermal poling on the 1.55 fm emission spectra in various Er$^{3+}$ -doped glasses was investigated with a special attention on the changes in the values of FWHM(Full Width at Half Maximum) intensity. Tellurite glasses poled at 28$0^{\circ}C$ with an electric voltage of 4 kV resulted in an approximately 6% increase in FWHM values compared with their unpoled counterparts. On the other hand, values for glasses, such as aluminosilicate, sulfide and chalcohalide, either decreased or remained unchanged. The characteristic results from tellurite glasses are most probably due to the presence of lone-pair electrons in the TeO$_4$ hi-pyramidal units that form the main network structure of tellurite glasses.

• Journal of the Korean Solar Energy Society
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• v.31 no.3
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• pp.126-132
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• 2011

Recently, high-rise apartment is being briskly built but there are problems such as lack of ventilation, stack effect and much energy consumption. Therefore It is recommended to develop a Small Wind Power System Combined Ventilator as a solution to solve these problems. The purpose of this study is to provide basis for Small Wind Power System Combined Ventilator in super high-rise apartment. This study conducted CFD simulation (Star-CCM) according to the shape of structures, building height and distance of two structures to identify the effect of wind speed increase when the structure is installed. As a result, pyramidal type was best suited for increase of wind speed. The best place was the front of the roof to main wind direction, and the best building height was 200m rather than 300m. If two or more small wind turbines combined ventilator are installed closely, vertical position to main wind direction is recommended. Horizontal position must necessarily be avoided, but height difference between two blades more than 3m showed good performance.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.1
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• pp.33-40
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• 1992

Several etching phenomena were observed and analyzed in diaphragm process performed on 4-inch (100) Si wafers for sensor application. In case of deep etching to above 300$\mu$m depth, the etch-defects appeared at etched surface could be classified into three categories such as hillocks, reaction products, and white residues. It was known that the hillock had a pyramidal shape or trapizoidal hexahedron structure depending on the density and size of the reaction products. The IR spectra showed that the white residue, which was due to the local over-saturation of Si dissolved in solution, was mostly Si-N-O compounds mixed with a small amount of H and C etc. Also, the difference in both the existence of etch-defects and etch rate distribution over a whole wafer was investigated when the etched surfaces were downward, upward horizontally and erective in etching solutions. The obtained data were analyzed through flow pattern in the etching bath. As the results, the downward and erective postures were favorable in the etch rate uniformity and the etch-defect removal, respectively.

• Toxicological Research
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• v.6 no.2
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• pp.191-204
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• 1990

Trimethyltin (TMT) induced lesions in the rat hippocampal formation was reviewed. Adult rats were treated with a single dose of 6.0 mg TMT/kg b.w. and were sacrificed between 3-60 days following exposure. On the hippocampal formation, the granule cells of fascia dentata showed early changes which subsided considerably at a later time when the destruction of the pyramidal neurons of the Ammon's horn became increasingly pronounced with time, leading to severe destruction of the structure. It is interesting to note that there was an inverse relationship of pathological involvement between the f.d. granule cells and the Ammon's horn neurons; i.e., when there was a large sparing of the granule cells. there was an extensive damage to the Ammon's horn and vice versa. This inverse relationship was also true between the $CA_3$neurons and the $CA_{1,2}$neurons in the Ammon's horn. Progressive zinc loss, as demonstrated by Timm's method, on the Mossy fibers was also observed. Similar Mossy fiber zinc depletion has been demonstrated in electrical stimulatory excitation condition of the perforant path to the hippocampus. Depletion of corticosterone, an inhibitor to the hippocampal neurons, by means of adrenalectomy will exaggerate the TMT induced hippocampal lesion. Neonatal study revealed that a unique degenerative pattern of the Ammon's horn could be established in accordance with exposure to TMT at specific maturation periods of the fippocampal formation: increasing destruction of the Ammon's horn with increasing synaptogenesis between the f.d. granule cells and the Ammon's horn neurons. Thus it is apparent that the damage of the Ammon's horn, upon exposure to TMT, may depend on the integrity and functional state of the f.d. granule cells. A hyperexcitory scheme and mechanism as the toxicity basis of TMT in the hippocampal formation is proposed and discussed.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.105-110
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• 2011

The doping procedure in crystalline silicon solar cell fabrication usually contains oxygen injection during drive-in process and removal of phosphorous silicate glass(PSG). In this paper, we studied the effect of oxygen injection and PSG on conversion efficiency of solar cell. The mono crystalline silicon wafers with $156{\times}156mm^2$, $200{\mu}m$, $0.5-3.0{\Omega}{\cdot}cm$ and p-type were used. After etching $7{\mu}m$ of the surface to form the pyramidal structure, the P(phosphorous) was injected into silicon wafer using diffusion furnace to make the emitter layer. After then, the silicon nitride was deposited by the PECVD with 80 nm thickness and 2.1 refractive index. The silver and aluminium electrodes for front and back sheet, respectively, were formed by screen-printing method, followed by firing in 400-425-450-550-$880^{\circ}C$ five-zone temperature conditions to make the ohmic contact. Solar cells with four different types were fabricated with/without oxygen injection and PSG removal. Solar cell that injected oxygen during the drive-in process and removed PSG after doping process showed the 17.9 % conversion efficiency which is best in this study. This solar cells showed $35.5mA/cm^2$ of the current density, 632 mV of the open circuit voltage and 79.5 % of the fill factor.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.51-55
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• 2011

In this paper, the optimized doping condition of crystalline silicon solar cells with 156 ${\times}$ 156 mm2 area was studied. To optimize the drive-in condition in the doping process, the other conditions except drive-in temperature and time were fixed. After etching 7 ${\mu}m$ of the surface to form the pyramidal structure, the silicon nitride deposited by the PECVD had 75~80 nm thickness and 2 to 2.1 for a refractive index. The silver and aluminium electrodes for front and back sheet, respectively, were formed by screen-printing method, followed by firing in $400-425-450-550-850^{\circ}C$ five-zone temperature conditions to make the ohmic contact. Drive-in temperature was changed in range of $828^{\circ}C$ to $860^{\circ}C$ and time was from 3 min to 40 min. The sheet resistance of wafer was fixed to avoid its effect on solar cell. The solar cell fabricated with various conditions showed the similar conversion efficiency of 17.4%. This experimental result showed the drive-in temperatures and times little influence on solar cell characteristics.

• Journal of the Korean Solar Energy Society
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• v.31 no.1
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• pp.37-43
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• 2011

In this paper, the optimized doping condition of crystalline silicon solar cells with $156{\times}156\;mm^2$ area was studied. To optimize the drive-in temperature in the doping process, the other conditions except variable drive-in temperature were fixed. These conditions were obtained in previous studies. After etching$7\;{\mu}m$ of the surface to form the pyramidal structure, the silicon nitride deposited by the PECVD had 75~80nm thickness and 2 to 2.1 for a refractive index. The silver and aluminium electrodes for front and back sheet, respectively, were formed by screen-printing method, followed by firing in 400-425-450-550-$850^{\circ}C$ five-zone temperature conditions to make the ohmic contact. Drive-in temperature was changed in range of $830^{\circ}C$ to $890^{\circ}C$to obtain the sheet resistance $30{\sim}70\;{\Omega}/{\box}$ with $10\;\Omega}/{\box}$ intervals. Solar cell made in $890^{\circ}C$ as the drive-in temperature revealed 17.1% conversion efficiency which is best in this study. This solar cells showed $34.4\;mA/cm^2$ of the current density, 627 mV of the open circuit voltage and 79.3% of the fill factor.

• Journal of architectural history
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• v.17 no.5
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• pp.39-53
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• 2008

This study aims to investigate and analyze the plan and structural system of 4 kan(間) by 4 kan(間) square church built in early 20th century. At that time, three kinds of traditional wooden structure church had been built under the circumstances of transitional era : Basilica style such as Ganghwa Anglican Church, 'ㄱ' shaped style such as Keumsan Church and $4{\times}4$ Square style such as Bukok Church and Jacheon Church that are concerned in this study. Traditional plans and structural system were mixed with new religious function and transformed into korean peculiar style. $4{\times}4$ Square style is a residual product in that process. Despite of it, little concerns on it till now. The results of this study are described as follows. 1. The plan of these $4{\times}4$ square churches is divided into three areas : cathedra($1{\times}1$), attendance($4{\times}2$), and intermediation($4{\times}2$). The location of cathedra is commonly the opposition part of main gate and projected out of the building. Attendance area was also divided into two, man and woman, because of keeping a distance with each other. 2. The structural system of these $4{\times}4$ square churches are somewhat different because of their size and roof style. In the case of Bukok church, $4{\times}4$ square fall off $3{\times}3$ and $2{\times}2$ gradually and turn into paljak(八作) roof, which enable us to get in traditional entering methods. On the contrary, Jacheon church use hipped roof but almost alike pyramidal roof, which could make us not to recognize entering in the aspect of gable part.

• Journal of the Korean Magnetic Resonance Society
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• v.9 no.2
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• pp.138-154
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• 2005

Vanadium-incorporated aluminophosphate molecular sieve $VO^{2+}-SAPO-5$ was studied by electron spin resonance (ESR) and electron spin echo modulation (ESEM) spectroscopies to determine the vanadium structure and interaction with various adsorbate molecules. It was found that the main species at low concentration of vanadium is a monomeric vanadium units in square pyramidal or distorted octahedral coordination, both in oxidation state (IV) for the calcined hydrated material and in oxidation state (V) for the calcined material. After calcinations in $O_2$ and exposure to moisture, only species A is observed with reduced intensities. It is suggested as a $VO(H_2O)_3^{2+}$ complex coordinated to two framework oxygen bonded aluminum. When calcined, hydrated $VO^{2+}-}SAPO-5$ is dehydrated at elevated temperature, a species loses its water ligands and transforms to $VO^{2+}$ ions coordinated to two framework oxygens (species B). Species B reduces its intensity, significantly after treatment with $O_2\;at\;600^{\circ}C$ for 5 h, thus suggesting oxidation of $V^{4+}\;to\;V^{5+}$. When dehydrated $VO^{2+}-SAPO-5$ contacts with $D_2O$ at room temperature, the EPR signal of species A is observed. Thus species assumed as a $VO^{2+}(O_f)_2(D_2O)_3$, by considering two framework oxygens. Adsorption of deuterated ethanol, propanol on dehydrated $VO^{2+}_{-}SAPO-5$ result in another new vanadium species E and F, respectively, which are identified as a $VO^{2+}-(CH_3CH_2OD)_3,\;VO^{2+}-(CH_3CH_2CH_2OD)_2$ complex. When deuterated benzene is adsorbed on dehydrated $VO^{2+}-SAPO-5$, another new vanadium species G, identified as a $VO^{2+}-(C_6D_6)$ is observed. Possible coordination geometries of these various complexes are discussed.

• Journal of The Korean Society of Clinical Toxicology
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• v.17 no.2
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• pp.66-78
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• 2019

Purpose: Thallium (TI+) autometallography is often used for the imaging of neuronal metabolic activity in the rodent brain under various pathophysiologic conditions. The purpose of this study was to apply a thallium autometallographic technique to observe changes in neuronal activity in the forebrain of rats following acute carbon monoxide (CO) intoxication. Methods: In order to induce acute CO intoxication, adult Sprague-Dawley rats were exposed to 1100 ppm of CO for 40 minutes, followed by 3000 ppm of CO for 20 minutes. Animals were sacrificed at 30 minutes and 5 days after induction of acute CO intoxication for thallium autometallography. Immunohistochemical staining and toluidine blue staining were performed to observe cellular damage in the forebrain following intoxication. Results: Acute CO intoxication resulted in significant reduction of TI+ uptake in major forebrain structures, including the cortex, hippocampus, thalamus, and striatum. In the cortex and hippocampal CA1 area, marked reduction of TI+ uptake was observed in the cell bodies and dendrites of pyramidal neurons at 30 minutes following acute CO intoxication. There was also strong uptake of TI+ in astrocytes in the hippocampal CA3 area following acute CO intoxication. However, there were no significant histological findings of cell death and no reduction of NeuN (+) neuronal populations in the cortex and hippocampus at 5 days after acute CO intoxication. Conclusion: The results of this study suggest that thallium autometallography can be a new and useful technique for imaging functional changes in neural activity of the forebrain structure following mild to moderate CO intoxication.