• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.437-440
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• 1998

We studied phosphorus doping effect on the epitaxial growth of $Si_{1-x}Ge_{x}$ film with high Ge fraction on Si substates at 550.deg. C by LPCVD. In a low $Ph_{3}$ partial pressure region such as below 1.25 mPa, the phosphorus dopant concentration increased linearly with increasing $PH_{3}$ partial pressure while the deposition rate and the Ge fraction were constant. In a higher $PH_{3}$ partial pressure region, the phosphorus dopant concentration and the deposition rate decreased, while the Ge fraction slightly increased. The deposition arate and the Ge fraction increased with increasing $GeH_{4}$ partial pressure while the phophours dopant concentration decreased. But the increasing rate of Ge fraction with incrasing $PH_{3}$ partial pressure was reduced at a high $GeH_{4}$ partial pressure. According to test results, it suggests that high surface coverage of phosphorus atoms suppress both the $SiH_{4}$ adsorption/reasction and the $GeH_{4}$ adsorption/reaction on the surfaces, and the effect is more stronger on $SiH_{4}$ than on $GeH_{4}$. In a higher $PH_{3}$ partial pressure region, the epitaxial growth is largely controlled by surface coverage effect of phosphorus atoms. The phosphorus surface coverage was slimited at a high $GeH_{4}$ partial pressure because adsorbed Ge atoms effectively suppresses the adsorption of phosphorus atoms.

• 한국환경생태학회지
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• 제33권2호
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• pp.228-236
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• 2019

본 연구는 남해 연안에서 채취한 퇴적물을 대상으로 수질의 환경변화에 의해 퇴적물이 용출 특성에 미치는 영향을 파악하기 위해 실험실에서 20일 동안 용출 배양실험을 진행하였으며, 퇴적물 인의 존재형태와 수질의 환경 인자, 총 인의 용출률을 측정하였다. 관찰 결과, 수층에서 미생물의 성장에 의해 용존 산소가 감소하여, 퇴적물의 산화환원전위가 낮아지는 혐기성환경이 진행되었다. 그에 따라 배양 초기일과 20일 후를 비교하면, 퇴적물 인의 존재 형태 중철 산화물과 결합한 인산염의 감소하는 변동성이 높게 나타났다. 이는 철 산화물이 환원될 경우 금속 이온과 분리된 무기인이 수중으로 이동하는 것을 의미하는데, 분리된 무기인은 플랑크톤에 의해 잘 흡수되는 특성을 가진다. 수층의 총 인을 분석한 결과 20일 차 0.304mg/L까지 지속적으로 증가하였으며, 산정된 용출률의 경우 배양 5일 이후 용존 산소의 감소와 높은 관계성을 보였다. 따라서 본 연구의 결과로부터, 수층의 부영양화를 관리하기 위한 요소로서 수질의 용존 산소와 퇴적물 인의 존재형태 중 철 산화물의 중요성을 확인할 수 있었다.

• 한국환경과학회지
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• 제28권5호
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• pp.511-520
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• 2019

This study was investigated to improve the phosphorus release and water quality by transformation of sedimentary P fraction for application of $CaO_2$. For the experiment, 0.5% (w/w) of $CaO_2$ was homogenized in the sediment and incubated with the control for 20 days. The analytical results showed that pH increased with $CaO_2$ and redox potential (ORP) was improved in the sediment of the reactor. The growth rate of chlorophyll-a was lower in the $CaO_2$ reactor and Dissolved Oxygen (DO) of overlying water maintained higher than that of the control. Total phosphorus (T-P) concentration in the overlying water increased from the initial concentration to 0.304mg/L in the control at 20 days. The reactor of $CaO_2$ was lowered by 29.3%. Ex-P, Fe-P and Ca-P in sediment P fraction were increased with the $CaO_2$. The formation of bound Fe-P and Ca-P in the sediments seemed to control the release of P by removing the Soluble Reactive Phosphorus (SRP) presented in the pore water. From the result, this indicated that the reduction of P release from the sediments seems to be effective in suppressing the eutrophication of P and improving the oxygen condition in the water quality with the application of $CaO_2$.

• 농촌계획
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• 제11권4호
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• pp.25-31
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• 2005

The present study was carried out to investigate the P fractions of surfical sediment of Dongjin sea area. Furthermore, potential released loading of adsorbed and non-apatite inorganic phosphorus were investigated in the sediment of Dongjin sea area. The contents of phosphorus fractions of the surficial sediment in Dongjin sea area were adsorbed-P 0.06%, nonapatite inorganic-P 13.02%, apatite-P 60.22%, and residual-P 26.70%. The most abundant fraction was apatite-P, residual-P, nonapatite inorganic-P, and adsorbed-P followed it. Potential released loading of adsorbed and non-apatite inorganic phosphorus surveyed 2.6 and 597ton respectively. These results show that sediment-managing and interception from external pollution are needed for water environmental maintenance of Dongjin sea area.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.314-316
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• 1997

We have studied the epitaxial growth and electrical properties of $Si_{0.8}Ge_{0.2}$, films on Si substrates at $550^{\circ}C$ by LPCVD. In a low $PH_3$, partial pressure region such as below 1.25 mPa, the phosphorus doping concentration increased proportionally with increasing $PH_3$ partial pressure while the deposition rate and the Ge fraction x were constant. In a higher $PH_3$ partial pressure region, the phosphorus doping concentration and the deposition rate decreased, while the Ge fraction slightly increased. The dependence of P incorporation rate on the $PH_3$ partial pressure was similar to the phosphorus doping concentration. According to test results, it suggests that high surface coverage of phosphorus atoms suppress both the $SiH_4$ adsorption/reaction and the $GeH_4$ adsorption/reaction on the surfaces, and the effect is more stronger on $SiH_4$ than on $GeH_4$. In a higher $PH_3$ partial pressure region, the deposition is largely controlled by surface coverage effect of phosphorus atoms.

• 환경위생공학
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• 제13권1호
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• pp.44-56
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• 1998

This study was performed to investigate the reaction characteristics of piggery wastewater for biological nutrient removal. The reaction characteristics were discussed the fraction of organics, the behavior of nitrogen, nitrification, denitrification, and the behavior of phosphorus. The fraction of readily biodegradable soluble COD was 11-12 percent. The ammonia nitrogen was removed via stripping, nitrification, autotrophic cell synthesis, and heterotrophic cell synthesis. The removal percents by each step were 12.1%, 68.9%, 15.0%, and 4.0%, respectively. Nitrification inhibition of piggery wastewater was found to occur at an influent volumetric loading rate over 0.2 NH$_{3}$-N kg/m$^{3}$/d. Denitrification rates were the highest in the raw wastewater and the lowest in the anaerobic effluent. The denitritation of piggery wastewater came out to be possible, and the rate of organic carbon consumption decreased about 10 percent. The phosphorus removed was released in the form of ortho-p in the aerobic fixed biofilm reactor, it was caused by autooxidation. The synthesis and release of phosphorus were related to the ORP and the boundary value for the phase change was about 170mV. In the synthesis phase, the phosphorus removal rate per COD removed was 0.023mgP$_{syn}$/mgCOD$_{rem}$. The phosphorus contents of the microorganism were 4.3-6.0% on a dry weight basis.

• The Korean Journal of Ecology
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• 제8권1호
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• pp.7-14
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• 1985

Biomass, carbon, nitrogen and phosphorus standing crops of bethic community were estimated at the trophic levels in the intertidal zone of Kum river estuary. Annual mean biomass of zoobenthos was 130.5g/$m^2$, body fraction 26.7g/$m^2$ and shell fraction 103.8 g/$m^3$. Biomass estimated as ash-free dry weight was total 28.9g/$m^2$, body fraction 20.2g/$m^2$ and shell fraction 8.7g/$m^2$ Carbon standing crops of zoobenthos were 15.9gC/$m^2$, in which organic carbon content was 7.0gC/$m^2$ and carbonate carbon was 8.9gC/$m^2$. Production efficiency by carbon standing crops from sediment to herbivores and carnivores and 10.6% and 16.0% in phosphorus, respectively. Annual primary production of benthic algae was crudely estimated to 329g.dw/$m^2$/yr by using the biomass and turn-over rate of benthic algae.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1992년도 추계학술대회 논문집
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• pp.22-27
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• 1992

Phosphorus doped hydrogenated microcrystalline silicon (${\mu}c$-Si:H) thin films were deposited by PECVD (Plasma Enhanced Chemical Vapour Deposition) method using 10.2% $SiH_4$ gas (diluted in Ar) and 308ppm $PH_3$ gas (diluted in Ar). The structural, optical and electrical properties of the films were investigated as a function of substrate temperature(15 to $400^{\circ}C$) and RF power(10 to 120W). The thin film deposited by varing substrate temperature had columnar structure and microcrystalline phase. The volume fraction of microcrystalline phase in the films deposited at RF power of 80W, increased with increasing substrate temperature up to $200^{\circ}C$, and then decreased with further increasing substrate temperature. Volume fraction of microcrystalline phase increased monotonously with increasing RF power at substrate temperature of $250^{\circ}C$. With increasing volume fraction of microcrystalline, electrical resistivity of films decreased to 0.274 ${\Omega}cm$.

• Applied Biological Chemistry
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• 제35권6호
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• pp.449-456
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• 1992

인산처리가 근류의 bacteroid 함량과 energy 상태에 미치는 영향을 살펴보기 위하여 Bradyrhizobium japonicum MN10을 접종한 대두식물(Glycine max [L.] Merr.)에 저해농도(0.05 mM-P)와 정상농도(1.0 mM-P)를 처리하여 온실에서 재배하였다. 인산결핍은 식물체의 근류량과 근류량 식물체량의 비에 유의성있는 감소를 보였다. 잎, 줄기, 뿌리의 인산농도는 인산결핍에 의하여 75%가 감소하였으나 근류의 인산농도는 40%만 감소하였다. 근류의 bacteroid 함량과 근류에서 전인산, 전질소의 bacteroid와 식물세포로의 분배는 인산결핍의 영향을 받지 않았으며 전질소의 22%, 전인산의 27%가 bacteroid에 존재하였다. 근류의 ATP농도, 전 adenylate 농도와 energy charge는 인산결핍에 의하여 각각 77%, 46%, 37%가 감소되었다. 인산결핍은 근류내 식물세포의 ATP 농도와 energy charge를 각각 86%, 59%를 감소시켰으나 bacteroid의 ATP농도와 energy charge에는 영향을 미치지 않았다. 이러한 결과는 근류가 인산의 강한 보유원이며, 기주식물에 대한 인산결핍조건하에서 bacteroid는 정상적인 인산 농도와 energy양을 함유한다는 것을 나타낸다.

• Applied Biological Chemistry
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• 제34권2호
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• pp.117-124
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• 1991

기주 식물에 대한 인산공급이 근류의 인산 형태와 bacteroid의 인산흡수에 미치는 영향을 살펴보고자 B. japonicum MN 110을 접종한 대두식물을 1.0, 0.25, 0.05 mM-P 조건에서 재배하였다. 1.0, 0.25, 0.05 mM-P 조건에서 재배한 대두식물의 근류 Pi 농도는 각각 4.1, 2.5, 2.0 mM이었으며 인산공급이 근류의 Pi, SOP, lOP의 분포에는 유의성 있는 영향을 미치지 못하였다. 0.25, 0.05 mM-P 조건에서 재배한 대두식물의 유엽 Pi 농도는 대조구(1.0 mM-P)의 각각 33%, 20%이었으며 노엽 Pi 농도는 대조구의 각각 16%, 7%였다. 잎에서는 인산 결핍이 전인산에 대한 Pi의 분포를 감소시켰으나 lOP의 분포는 증가시켰다. 근류내의 bacteroid의 수는 $0.87-1.30{\times}10^{11}\;/GFW\;nodule$이었으며, 인산흡수도는 15-16 pmoles /min/$10^8$ bacteroid로 기주식물의 인산공급에는 영향을 받지 않았다 이러한 결과는 인산결핍 대두식물의 근류내 Pi농도는 bacteroid의 생육과 번식에 충분하며 인산결핍에 의하여 기주식물의 생육이 저해될 때에도 bacteroid의 인산흡수는 억제상태에 있음을 나타낸다.