• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.405-406
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• 2013

Ga-doped ZnO (GZO)는 $300^{\circ}C$ 이상의 온도에서는 전기적으로 불안정하기 때문에 CIGS, CdTe, DSC와 같은 태양전지의 높은 공정온도 때문에 사용이 제한적이다. ZTO thin film은 Al2O3, SiO2, TiO2, ZnO tihin film과 비교하여 산소 및 수분에 대하여 투과성이 상대적으로 낮은 것으로 알려져 있다. 따라서 GZO single layer에 비하여 ZTO-GZO multi-layer를 구성하여 TCO를 제작하면, 높은 공정온도에서도 사용 가능하다. 실제 제작된 GZO single layer (300 nm)에서 비저항이 $7.69{\times}10^{-4}{\Omega}{\cdot}cm$에서 $500^{\circ}C$에서 열처리 후 $7.76{\times}10^{-2}{\Omega}{\cdot}cm$으로 급격하게 상승한다. ZTO single layer (420 nm)는 as-grown에서는 측정 불가했지만, $400^{\circ}C$에서 열처리 후 $3.52{\times}10^{-1}{\Omega}{\cdot}cm$ $500^{\circ}C$에서 열처리 후 $4.10{\times}10^{-1}{\Omega}{\cdot}cm$으로 열처리에 따른 큰 변화가 없다. 또한 ZTO-GZO multi-layer (720 nm)의 경우 비저항이 $2.11{\times}10^{-3}{\Omega}{\cdot}cm$에서 $500^{\circ}C$에서 열처리 후 $3.67{\times}10^{-3}{\Omega}{\cdot}cm$으로 GZO에 비하여 상대적으로 변화폭이 작다. 또한 ZTO의 두께에 따른 영향을 확인하기 위하여 ZTO를 2 scan, 4 scan, 6 scan 공정 진행 및 $500^{\circ}C$에서 열처리 후 ZTO, ZTO-GZO thin film의 비저항을 측정하였다. ZTO의 경우 $3.34{\times}10^{-1}{\Omega}{\cdot}cm$ (2 scan), $3.62{\times}10^{-1}{\Omega}{\cdot}cm$ (4 scan), $4.1{\times}10^{-1}{\Omega}{\cdot}cm$ (6 scan)으로 큰 차이가 없으며, ZTO-GZO에서도 $3.73{\times}10^{-3}{\Omega}{\cdot}cm$ (2 scan), $3.42{\times}10^{-3}{\Omega}{\cdot}cm$ (4 scan), $3.67{\times}10^{-3}{\Omega}{\cdot}cm$ (6 scan)으로 큰 차이가 없음을 확인하였다. 염료감응 태양전지에 적용하여 기존에 사용되는 FTO대신에 ZTO-GZO를 사용하며, 가격적 측면, 성능적 측면에서 개선 가능할 것으로 생각된다.

• Analytical Science and Technology
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• v.8 no.1
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• pp.1-7
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• 1995

Spectrophotometric determination of U(VI) and Th(IV) by Flow injection method is described. Chrome Azurol S forms water soluble complexes with U(VI) and Th(IV) in the presence of cethyltrimethylammonium bromide. The maximum adsorption of U(VI) and Th(IV) complexes are at 600nm with molar absorptivity of $2.3{\times}10^5Lmol^{-1}cm^{-1}$ and 611nm with molar absorptivity of $3.8{\times}10^5Lmol^{-1}cm^{-1}$ in acetate buffer medium having pH 5.0 and 5.5. The calibration curves of U(VI) and Th(IV) are linear over the range of 0.1~0.8ppm and the correlation coefficients are ca. 0.9960 and 0.9930 respectively. The detection limits(S/N) are 20ppb for U(VI) and 15ppb for Th(IV). The relative standard deviation are ${\pm}1.8%$ for U(VI) and ${\pm}2.1%$ for Th(IV). The sample throughput was ca. $50hr^{-1}$.

• Journal of Aquaculture
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• v.6 no.2
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• pp.71-87
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• 1993

Two forms of sea mustard, Undaria Pinnatifida were cultured in order to compare the morphological characteristics and the efficiency of production. U. Pinnatifida f. distans was collected from Wando, Korea and U. Pinnatifida f. typica was transplanted from Sanriku, Japan. The latter form grew faster in length and weight than the former. Maximum growth was shown in early April for both forms, and the growth rates decreased after this. Absolute growth rates between the two forms were quite different. Average total lengths at the harvest season was 161.1cm in U. Pinnatifida f. distans and 183.5 em in U. Pinnatifida f. typica and average weights of those two forms were 1,003.4g and 1,314.6g, respectively. The weight of available parts for the salting process of the two forms were 734.8g and 968.5g, respectively. The rates of total length versus the length of the available part of the two forms were $76\%$ and $83\%$, respectively and those of the total length versus weight of the available part of them were $43.8\%$ and $52.7\%$, respectively. The results of this study suggest that the U. pinnatifida f. typica had more available part per unit weight than that of the U. pinnatifida f. distans for the efficiency of salt processing.

• Korean Journal of Materials Research
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• v.8 no.11
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• pp.977-981
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• 1998

Controlling the wafer temperatures from 200 to$500^{\circ}C$, low resistive tungsten thin films used for VLSI metallization are deposited by PECVD method. Resistivities of plasma deposited tungsten thin films are very sensitive to the $H_2/WF_6 $ partial pressure ratios. Residual stress behaviors of the films as a function of plasma power density were also studied. At the power density under the $0.7W/\textrm{cm}^2$, residual stress of W film is about $2.4\times10^9dyne/\textrm{cm}^2$. When the power density is. however, increased from 1.8 to $2.7W/\textrm{cm}^2$, residual stress is suddenly increased from $8.1\times10^9$ to $1.24\times10^{10}dyne/\textrm{cm}^2$ ue to the ion or radical bombardment at high power density.

• Korean Journal of Agricultural Science
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• v.29 no.1
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• pp.44-54
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• 2002

The fresh eggs of African ostrich in Korea were used in this study to investigate their interior and exterior quality characteristics. In ostrich egg shape characteristics, long and short length were measured as 15.1~16.1 cm and 12.1~13.6 cm, respectively. The egg shape index was calculated as 81.0 and the egg shell showed a more g loss white in color than that of hen egg. Calculated breaking strength of egg shell and egg shell surface based on the equation were $41.155kg/cm^3$ and $804.7cm^2$, respectively. Average egg shell thickness including egg shell membrane was 1.89 mm and there are no differences among parts of the shell. The egg shell membrane thickness was 0.10 mm showing relatively thick in equator compared with that of blunt end. The ave rage number of egg shell pores was counted as $19.7/cm^2$ showing relatively high number of egg shell pores at point end and the total number of egg shell pores in an egg was estimated as 15,241. The relative port ion of each parts based on egg weight was estimated as 25.1% for egg yolk, 58.2% for egg white, 16.7% for egg shell and the ratio of egg yolk to egg white (Y/W) was 0.43. The average diameter and the ave rage height of ostrich egg white were 19.7 cm and 13.2 mm, respectively. Calculated the H.U (Haugh Unit) was -69.7 and the pH was 8.3. In ostrich egg yolk, the diameter, the height, the egg yolk index, and it's pH were calculated as 14.4 cm, 29.4 mm, 0.20, and 6.6, respectively. And the egg yolk color showed a more thin in yellow chroma compared with that of hen egg as due to it's thicker membrane.

• Journal of Korean Neurosurgical Society
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• v.30 no.5
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• pp.553-560
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• 2001

Objective : The objective of this study was to determine the photodynamic therapeutic response of U-87 human glioma cell in vitro as well as in the nude rat xenograft model using photofrin as photosensitizer. Material and Method : U-87 cells were cultured on 96-well culture plates, photofrin(Quadralogic Technologies Inc., Vancouver, Canada) was added into the cell culture medium at concentration of $1{\mu}g/ml$, $2.5{\mu}g/ml$, $5{\mu}g/ml$, $10{\mu}g/ml$ and $20{\mu}g/ml$. 24 hour after drug treatment, cells were treated with optical(632nm) irradiation of $100mJ/cm^2$, $200mJ/cm^2$ and $400mJ/cm^2$. Photofrin(12.5mg/kg, i.p.) was administered to 28 nude rats containing intracerebral U-87 human glioma as well as 26 normal nude rats. 48 hours after administration, animals were treated with optical irradiation(632nm) of $35J/cm^2$, $140J/cm^2$ and $280J/cm^2$ to exposed tumor and normal brain. The photofrin concentration was measured in tumor and normal brain in a separate population of animals. Results : By MTT assay, there was 100% cytotoxicity at any dose of photofrin with optical irradiation of $200mJ/cm^2$ and $400mJ/cm^2$. But at the optical irradiation of $100mJ/cm^2$ cells were killed in dose dependent manner 28.5%, 49.1%, 54.4%, 78.2%, and 84.6% at concentration of $1{\mu}g/ml$, $2.5{\mu}g/ml$, $5{\mu}g/ml$, $10{\mu}g/ml$ and $20{\mu}g/ml$, respectively. Dose dependent PDT lesions in both tumor and normal brain were observed. In the tumor lesion, only superficial tissue damage was found with optical irradiation of $35J/cm^2$. However, in the optical irradiation group of $140J/cm^2$ and $280J/cm^2$ the volume of lesions was measured of $7.2mm^3$ and $14.0mm^3$ for treatment at $140J/cm^2$ and $280J/cm^2$, respectively. The U-87 bearing rats showed a photofrin concentration in tumor tissue of $6.53{\pm}2.16{\mu}g/g$, 23 times higher than that found in the contralateral hemisphere of $0.28{\pm}0.15{\mu}g/g$. Conclusion : Our data indicate that the U-87 human glioma in vitro and in the xenografted rats is responsive to PDT. At these doses, a reproducible injury can be delivered to human glioma in this model. Strategies to spare the normal brain collateral damage are being studied.

• Food Science and Preservation
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• v.11 no.2
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• pp.182-188
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• 2004

This study was carried out to investigate nutritional composition and physicochemical properties of waxy(WGR) and nonwaxy(NWGR) germinated brown rice. Amylose contents of WGR(moisture content 15.45 %) and NWGR (moisture content 15.02%) were 4.9% and 17.9%. Reducing sugar of those were 4.91% and 2.28%. The free sugar contents of WGR were glucose 0.42%, sucrose 0.15%, maltose 0.27% and that of NWGR were glucose 0.59%, sucrose 0.50%, maltose 0.24%, respectively. Color value of WGR and NWGR were L=60.30, a=2.12, b=23.52 and L=59.51, a=3.15, b=23.04, respectively. Degree of gelatinization of WGR and NWGR were 7.67%, 5.21% and hardness of WGR and NWGR were 7.53 kg$\_$f//$\textrm{cm}^2$, 8.93 kg$\_$f//$\textrm{cm}^2$. Vitamin E contents of those were 271.8 $\mu\textrm{g}$/kg, 310.6 $\mu\textrm{g}$/kg and total dietary fiber contents of those were 4.21%, 3.17%. Total amino acids of brown rice, nonwaxy germinated brown rice and cooked germinated brown rice were 126.8 mg/l00 g, 90.8 mg/l00 g and 106.5 mg/l00 g, respectively. Among amylogram characteristics of WGR and NWGR, initial gelatinization temperature, peak viscosity, breakdown, setback were 42$^{\circ}C$, 498 B.U., 94 B.U., -48 B.D. and 70$^{\circ}C$, 212 B.D., 0 B.D., 123 B.D., respectively. Sensory properties of germinated brown rices were affected by color and flavor. Palatability score of WGR that intensity score of color and flavor were lower than that of NWGR showed high.

• 한국해양학회지
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• v.19 no.2
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• pp.141-152
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• 1984

In order to investigate the circulation dynamics of the Keum River estuary, 300velocity fields obtained at six sites over two tidal cycles by using instantaneous profiling technique were analyzed in detail. In this investigation, the variability of shear velocity, bottom shear stress, drag coefficient, and roughness length scale were confirmed. The measured values of the bottom boundary drag coefficient show wide range of variations, i.e., C$\_$100/=6.78${\times}$10$\^$-5/∼1.15${\times}$10$\^$-1/, and the mean of 300 measurements is 1.6${\times}$10$\^$-2/. The relationship between U* and C$\_$100/ also show the scatter in values. However, overall mean values over two tidal cycles at 6 stations show that if U* 1cm/s, C$\_$100/ is unpredictable, if U* 1cm/s, C$\_$100/ increase with U*. The values of Re$\_$100/ and C$\_$100/ have scatter. But the overall mean values over two tidal cycles show that if Re$\_$100/ 3.6${\times}$10$\^$5/, C$\_$100/ is unpredictable, if Re$\_$100/ 3.6${\times}$10$\^$5/, C$\_$100/=1.4${\times}$10$\^$-2/. Finally the flow regime of the Keum River estuary was classified as "subcritical fully turbulent" flow.

• Journal of agriculture & life science
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• v.53 no.2
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• pp.65-75
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• 2019

Stem and root of elm trees have used as traditional medical materials, but there is little information on the distribution and resources of habitats. Korean native growing Ulmus spp. (U. davidiana var. Japonica, U. parvifolia, U. davidiana, and U. macrocarpa) genetic resources studied through The National Forest Inventory of Korea data and field survey. The distributions of U. davidiana var. japonica according to elevation distributed evenly. Both U. parvifolia and U. davidiana were inhabited mostly at less than 200 m of altitude. Each Ulmaceae species widely were distributed nationwide, but a dominant species was different depending on locals. It observed that Ulmaceae inhabits mainly in steep slopes of 31-45 degrees. Most of the habitats regenerated by natural seeding and the most abundant species were a codominant tree. Distribution of trees in U davidiana var. japonica was 7 m-13 m, and in young U. parvifolia and U. macrocarpa, more than 25% of young trees less than 7 m observed. The distribution of the diameter of breast height of the U. davidiana var. japonica was 46.4% for 11-20 cm, 52.6% for 11-20 cm in U. parvifolia. The average T/R ratio was 0.83, and the mean weight ratio of root bark was 62%. As the results of this study, the domestic Ulmaceae biomassare very small. It is difficult to harvest in that the habitat on the slope. Thus, it is too hard to develop functional materials using biomass at present. Therefore, it is necessary to develop technology for the selection and propagation of elite trees of Ulmaceae.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.5
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• pp.746-752
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• 2022

Kiribati, a South Pacific island, and its surrounding countries are gradually submerging to rising sea levels. The sea level continues to change according to the degree of thermal expansion of glaciers and seawater that decreases with increase in temperature. Global warming affects both the amount and volume of seawater, thus increasing sea level. Tidal phenomena occur twice a day to the attraction of celestial bodies such as the moon and the sun. The moon changes the angle of orbiting surface with the Earth equator every 18.6 years, and the magnitude of the tidal force changes depending on the distance between the Earth equator and the moon orbital surface. The University of Hawaii Sea Level Center selected Tarawa, Christmas, Kanton of Kiribati,, Lautoka, Suva of Fiji,Funafuti of Tuvalu, Nuk1u'alofa of Tonga, and Port Vila of Vanuatu. When comparing tide levels for each year for 19 years, the focus was on checking the change in sleep to Tide levels, and rising sea levels was the effect of Tide levels. The highest astronomical tides (HAT) and lowest astronomical tides (LAT) were identified as Tarawa 297.0, 50.8 cm, Christmas 123.8, 19.9 cm, Kanton 173.7, 39.9 cm, Lautoka 240.7, 11.3 cm, Funafuti 328.6, 98.4 cm, Nuk1u'alofa 188.8, 15.5 cm, Port Vila 161.5, -0.5cm, respectively. The Sea level rising speed was Tarawa 3.1 mm/year, Christmas -1.0 mm/year, Kanton 1.6 mm/year, Lautoka 3.1 mm/year, Suva 7.4 mm/year, Funafuti 1.4 mm/year, Nuk1u'alofa 4.2 mm/year, and Port Vila -1.2 mm/year, respectively