• Journal of the Korean Ceramic Society
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• v.49 no.6
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• pp.637-641
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• 2012

Due to its high production cost and relatively high energy consumption during the Siemens process, poly-silicon makers have been continuously and eagerly sought another silicon route for decades. One candidate that consumes less energy and has a simpler acidic and metallurgical purification procedure is upgraded metallurgical-grade (UMG) silicon. Owing to its low purity, UMG silicon often requires special steps to minimize the impurity effects and to remove or segregate the metal atoms in the bulk and to remove interfacial defects such as precipitates and grain boundaries. A process often called the 'gettering process' is used with phosphorus diffusion in this experiment in an effort to improve the performance of silicon solar cells using UMG silicon. The phosphorous gettering processes were optimized and compared to the standard POCl process so as to increase the minority carrier lifetime(MCLT) with the duration time and temperature as variables. In order to analyze the metal impurity concentration and distribution, secondary ion mass spectroscopy (SIMS) was utilized before and after the phosphorous gettering process.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.57.2-57.2
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• 2010

최근 친환경적이고 저투자비용의 빠른 생산성을 가진 야금화학적인 방법으로의 태양전지급 실리콘 생산공정이 빠르게 성장하고 있다. 이로 인해 금속급 실리콘(MG-Si)에서부터 태양전지급 실리콘(SoG-Si)으로의 정련공정 또한 많은 연구가 진행되고 있다. 본 연구에서는 UMG-Si 내 주요 불순물인 Boron함량을 SoG-Si 순도로 정련하는 것을 목표로 기존의 방법과 달리 전자기연속주조정련법을 사용하여 도가니 비접촉식 용융 후 스팀플라즈마토치를 통해 Boron을 제거하고자 하였다. 실험에 사용한 가스 유량은 $H_2O$ 0.3~1.0ml/min, $H_2$ 20~40ml/min 이며 실험 후 ICP-MASS 분석 결과 초기 Boron 함량 2.9ppm으로부터 0.17ppm으로 줄었음을 확인하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.236-236
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• 2010

P-type의 단결정, 다결정, UMG 기판을 이용하여 phosphorus툴 확산시킨 후 열처리한 external gettering 방식으로 실리콘 내부에 있는 불순물을 제거하였고, 기판의 lifetime 변화를 $\mu$-PCD를 이용하여 측정하였다. phosphorus를 $850^{\circ}C$에서 기판 내부로 20분 확산시킨 후 기판의 온도와 시간을 변화시키면서 gettering 공정을 시행하였다. 에미터층으로 인해 기판의 bulk lifetime이 부정확해 지는 것을 방지하기 위해서 NaOH를 이용하여 에미터층을 제거한 후 $\mu$-PCD를 이용하여 lifetime을 측정하였다. 또한 기판의 표면효과를 최소화하기 위해서 lifetime 측정전에 iodine을 이용하여 표면 passivation을 하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.438-438
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• 2009

We have investigated the effect of forming gas annealing for Upgraded Metallurgical Grade (UMG)-silicon solar cell in order to obtain low-cost high-efficiency cell using post deposition anneal at a relatively low temperature. We have observed that high concentration hydrogenation effectively passivated the defects and improved the minority carrier lifetime, series resistance and conversion efficiency. It can be attributed to significantly improved hydrogen-passivation in high concentration hydrogen process. This improvement can be explained by the enhanced passivation of silicon solar cell with antireflection layer due to hydrogen re-incorporation. The results of this experiment represent a promising guideline for improving the high-efficiency solar cells by introducing an easy and low cost process of post hydrogenation in optimized condition.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.5
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• pp.195-199
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• 2008

Production of the silicon feedstock for the semiconductor industry cannot meet the requirement for the solar cell industry because the production volume is too small and production cost is too high. This situation stimulates the solar cell industry to try the lower grade silicon feedstock like UMG (Upgraded Metallurgical Grade) silicon of 5$\sim$6 N in purity. However, this material contains around 1 ppma of dopant atoms like boron or phosphorous. Calculation of the composition profile of these impurities using segregation coefficient during crystal growth makes us expect the change of the type from p to n : boron rich area in the early solidified part and phosphorous rich area in the later solidified part of the silicon ingot. It was expected that the change of the growth speed during the silicon crystal growth is effective in controlling the amount of the metal impurities but not effective in reducing the amount of dopants.

• Korean Journal of Community Nutrition
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• v.16 no.5
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• pp.569-579
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• 2011

The purpose of this study was to determine the urinary Ca, P, Mg, Zn, Cu, and Mn levels and bone mineral density (BMD) in sixty-two postmenopausal women. The study was conducted through anthropometric checkup, 24-hour recall, 24-hour urine and bone mineral density using DEXA. Average age, height, weight and body fat of the subjects were respectively 65.39 years, 150.19 cm, 58.03 kg and 37.22%. The average spine and femoral neck BMD of subjects were -2.19, -3.13. The mean intakes of Ca, P and Mg were 524.7 mg, 993.10 mg, and 254.6 mg and those of Zn, Cu and Mn were 8.6 mg, 1.5 mg, and 3.5 mg. The average 24-hour urinary excretion of Ca (UCa), P (UP) and Mg (UMg) were 161.07 mg, 673.68 mg, and 99.87 mg. The average 24-hour urinary excretion of Zn (UZn), Cu (UCu) and Mn (UMn) were 366.50 ${\mu}g$, 22.57 ${\mu}g$, and 1.55 ${\mu}g$. Ca intake showed significantly positive correlations with urinary UCa (p < 0.05), UMg (p < 0.01) and spine BMD (p < 0.05). P intake showed significantly positive correlations with UCa (p < 0.05), UMg (p < 0.05) and UZn (p < 0.05). Mg intake showed significantly positive correlations with UZn (p < 0.05) and Mn intake showed significantly positive correlations with UCa (p < 0.05). Multiple regression analysis indicates that Ca intake and UMg is the most important factor to increase spine BMD. On the other hand, UCa is the most important factor to decrease spine BMD. Higher femoral neck BMD was related to UP, while lower femoral neck BMD was related to UCa. In conclusion, Dietary intake of Ca showed positive effect of spine BMD, while excessive P intake showed negative effect on BMD due to increases in UCa, UMg and UZn. Further studies are required to investigate the relationship between bone metabolism and mineral excretion.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3863-3868
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• 2012

In this study mitochondrial D-Loop variations in Iranian prostate cancer and benign prostatic hyperplasia (BPH) patients were investigated. Tumour samples and corresponding non-cancerous prostate tissue from 40 prostate cancer patients and 40 age-matched BPH patients were collected. The entire mtD-loop region (16024-576) was amplified using the PCR method and products were gel-purified and subjected to direct nucleotide sequencing. A total of 129 variations were found, the most frequent being 263A${\rightarrow}$G and 310T${\rightarrow}$C among both BPH and prostate cancer patients. Variation of 309 C${\rightarrow}$T was significantly more frequent in prostate cancer patients (P value<0.05). Four novel variations were observed on comparison with the MITOMAP database. Novel variations were np16154delT, np366G${\rightarrow}$A, np389G${\rightarrow}$A and 56insT. There was no correspondence between the different variations and the age of subjects. Considering that D-loop variations were frequent in both BPH and prostate cancer patients in our study, the fact that both groups had high average age can be a possible contributing factor. D-loop polymorphisms and microsatellite instability can influence cell physiology and result in a benign or malignant phenotype. Significantly higher frequency of 309 C${\rightarrow}$T variation in cancer patients is a notable finding and must be a focus of attention in future studies.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.10
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• pp.175-200
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• 2004

Bei verschiedenen $Gespr\"{a}chen$ zwischen Frauen und $M\"{a}nnern$ sind mehrere Unterschiede in $Gespr\"{a}chsstrategien$ und -verhalten des jeweiligen Geschlechts zu beobachten. Herkemmlichen Ansichten nach $f\"{u}hrten$ $M\"{a}inner$ $Gespr\"{a}iche$ mit Frauen eher dominativ, $w\"{a}hrend$ Frauen eine deutliche Vorliebe $f\"{u}r$ kooperativ erlaufende $Gespr\"{a}che$ zeigen. Um die $G\"{u}ltigkeit$ dieser Perspektive zu $pr\"{u}fen$, wurden in dieser Albeit insgesamt $zw\"{o}lf$ Beratungsgesprache herangezogen. Daraus ergab sich, dass $M\"{a}nner$ im $Gespr\"{a}ich$ statistisch $h\"{a}ufiger$ die anderen $Gespr\"{a}chsteilnehmer$ unterbrechen. Da ein $Gespr\"{a}ch$ ein komplex vernetztes soziales Geschehen ist, sollte diese Statistik bei der Bestimmung der $Gespr\"{a}chsverhalten$ von zwei Geschiechtern keine entscheidende Rolle spielen. Im Anschluss daran habe ich mick mit Hilfe einiger im Internet gesammelten Daten, mit den $Gesp\"{a}chsverhalten$ bei der so genannten Online-Kommunikation befasst. Bei der Online-Kommunikation lassen sich zwei kontrastive verbale $Umg\"{a}nge$ der Geschlechtern beobachten, $n\"{a}mlich$ ein reibungslos ablaufendes IRC(Internet Relay Chatting) und eine $auff\"{a}llige$ Debatte, die mehrfache Konflikte zwischen den Beteiligten zeigt. Um diese $Ph\"{a}nomene$ auf der Basis der $Gespr\"{a}chsanalyse$ zu $erl\"{a}utern$, werden vol allem das Konzept der Kooperation beim $Gespr\"{a}ch$ und die Dynamik der $Gespr\"{a}chsstruktur$ erneut begriffen. $Schlie{\ss}lich$ werden die unterschiedlichen $Gespr\"{a}chsverhalten$ von Frauen und $M\"{a}nnern$ folgend wiedergegeben: Bei realen Face-To-Face-$Gespr\"{a}chen$ setzen Frauen den Schwerpunkt auf die emotionale und interaktive Kooperation, $w\"{a}hrend$ Manner ihn auf die kognitive Kooperation setzen. Dieser Sachverhait $\"{a}ndert$ sich aber bei der Online-Kommunikation. Auch Manner halten die emotionale und interaktive Kooperation $f\"{u}r$ wichtig und $f\"{u}hren$ mehr kooperative und reibungslose $Gespr\"{a}iche$ mit Frauen. Doch in einer Debatte um ein Thema $verh\"{a}lt$ sich jeder Beteiligte anders. Die moisten benutzen die Strategien, die den geringen Unterschied zwischen den Geschlechtern in Anfangsbedingungen $vergr\"{o}{\ss}ern$, und gleichzeitig die individuellen Unterschiede zwischen demselben Geschiecht verschleichen. Dadurch kann eine Debatte zwischen Geschlechten in Streit ohne Kompromisse geraten.