• Applied Biological Chemistry
• /
• v.21 no.1
• /
• pp.58-62
• /
• 1978

Dry weight, and mineral content in leaves, stems, and roots of the ginseng plant (Panax ginseng C.A. Meyer) were investigated. The highest T/R ratio, 0.52, was observed in a four year old plant due to a vigorous growth of the plant at this age. Also the dry weight increase was rather higher in the younger root than the older one. Mineral content of the plant was rather higher in the younger root than the older one. Potassium content in leaves and stems was higher than those of nitrogen and phosphorus. Generally, the leaves contained more iron and manganese than any other micronutrients. The iron content amounted to $1,000{\sim}2,000ppm$ in leaves. Zinc content was higher in stems and leaves than roots especially in stems of the younger roots. Total amount of the up-taken N, $P_2O_5$, and $K_2O$ per 10a in six years was 10.2kg, 2.3kg and 14.9kg respectively, indicating the considerable abounts of $K_2O$ was absorbed.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.282-282
• /
• 2012

본 연구에서 SiOC 박막을 제작하기 위해서 RF 마그네트론 스퍼터링법을 이용하여 유량별 RF 파워의 변화에 따라서 AZO 박막을 성장시켰으며 박막의 광학적 특성을 조사하였고 투명 전도성 박막으로써 AZO 박막을 SiOC 박막 위에 성장시켜서 광학적인 특성을 조사하였다. Si 웨이퍼의 종류에 따라서 광학적인 특성에 조금의 변화가 있는 것을 확인하였으며, n-type Si의 경우 electron transition에 의한 emission 특성이 달라지는 것에 비하여 상대적으로 p-type Si의 경우 변화가 거의 없는 것으로 나타났다. 일반적으로 사용되는 SiO2 산화막 위에 증착한 AZO 박막에 비하여 SiOC 박막 위에 증착할 경우 빛의 흡수가 많이 일어나는 것을 확인할 수 있었으며, AZO/SiOC 박막의 반사도 역시 많이 감소하였으며, 이러한 전기적인 특성은 태양전지에서 전면전극으로 사용할 경우 반사방지막으로서의 특징도 나타낸다는 것을 의미한다. 스퍼터 방법에 의한 증착법은 낮은 온도에서도 공정이 가능하다는 장점이 있으며, 절연특성이 우수한 SiOC 박막을 AZO 박막의 보호막으로 사용할 경우 용도에 따라서 우수한 특성을 나타낼 수 있음을 확인하였다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.09a
• /
• pp.346-349
• /
• 2004

국내에 자연 방치된 폐광산에 대한 문제가 대두되면서 폐광산 주변지역에 대한 산성광산폐수와 중금속 광산폐기물의 오염실태조사가 활발히 진행되고 있다. 본 연구는 폐광산의 유출수와 광산폐기물에 주변 오염지하수 내의 중금속 As, Cd, Pb, Fe, Mn, Zn, Cu에 대하여 무기 응집제의 첨가와 pH의 조절에 의한 제거효율을 .실내 배치실험을 통하여 규명하였다. 본 실험을 통하여 황산알루미늄(Al$_2$(SO$_4$)$_3$ㆍ13～14$H_2O$), 염화 제2철(FeCl$_3$ㆍ6$H_2O$), 황산 제2철(Fe$_2$(SO$_4$)$_3$ㆍ n$H_2O$)을 이용하여 오염수내 중금속을 90%이상 제거할 수 있었으며, 폐광산 침출수나 오염 지하수의 중금속 제거에 0.1 wt%의 응집제 첨가만으로 응집제를 이용한 화학적 처리 방법이 효과적으로 사용될 수 있을 것으로 판단되었다.

• Korean Journal of Environmental Agriculture
• /
• v.20 no.4
• /
• pp.238-243
• /
• 2001

Mass reduction and physicochemical properties of the produced compost were investigated during composting domestic food wastes without additive. A small composter used in this study had the height of 15 cm from the center of bottom half circle (diameter 24 cm) up to under the lid, the side length of 50 cm and the horizontal lid angle of $50^{\circ}$ and was operated at the heating unit temperature of $85^{\circ}$. It was mixed by the rotating arm for two minutes in every half hour while supplied with air flow at 3 L/min for 10 minutes in every half hour. This condition was found in a preliminary experiment as optimal for keeping the water content of composting material in the optimal range without adding any bulking materials. The domestic food wastes were added into the composter at the rate of 1 kg/day without additives during composting. The results were as follows; during the composting process, water content maintained in the range of $51.0{\sim}53.5%$. Hemicellulose and lignin contents did not show any tendency, but cellulose content decreased. During the composting process, $NH_3-N$ and $NO_2-N$ were not detected due to nitrification. The contents of inorganic compounds did not increase during the composting process. They were in the range of $1.32{\sim}1.71%\;P_2O_5$, $1.29{\sim}1.48%\;CaO$, $0.41{\sim}0.49%\;MgO$, and $0.38{\sim}0.74%\;K_2O$. For 20 days, weight reduction rate was 67.5% in wet basis, and decomposition rate was 48% in dry basis. Concentration of heavy metals (Cu, Cr, Cd, Pb, Zn, Hg, As) was less than the limiting value of the compost. Maturity of the produced compost was 3 grade through reaching maximum temperature of $46{\sim}48^{\circ}C$.

• The Korean Journal of Mycology
• /
• v.25 no.4 s.83
• /
• pp.369-376
• /
• 1997

These researches were carried out for improvement of medium for mycelial growth of Hericium erinaceus isolate KU-1. It grew well at pH 4 and $25^{\circ}C$. Glucose and sucrose were favorable carbon sources for mycelial growth. As nitrogen sources, ammonium acetate and arginine enhanced mycelial growth. Optimum C/N ratio was 200. Based On the results, the following recipe is suggested for synthetic medium for the mycelial growth: glucose 18.02 g, arginine 2.613 g, ammonium acetate 2.313 g, $CaCl_2\;0.33\;g$, $KH_2PO_4\;8.5\;g$, $MgSO_4{\cdot}7H_2O\;2.0\;g$, $FeSO_4{\cdot}7H_2O\;0.02\;g$, $ZnSO_4{cdot}7H_2O\;0.02\;g$, $MnSO_4{\cdot}7H_2O\;0.02\;g$, water 1 liter. This medium was superior for the mycelial growth to other conventional media such as Yeast malt extract agar (YMA), Park medium, Potato dextrose agar (PDA), Malt extract agar, Czapek-dox agar, Macaya-lizano medium and Yeast extract agar. This new synthetic medium is designated as Ko medium.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.4
• /
• pp.1204-1208
• /
• 2012

A new photoelectrode composed of $Sb_6O_{13}$ nanoparticles with the size of 20-30 nm has been prepared via thermolysis of a colloidal antimony pentoxide tetrahydrate ($Sb_2O_5{\cdot}4H_2O$) suspension. The $Sb_6O_{13}$ electrode showed good semiconducting properties applicable to dye-sensitized solar cells (DSSCs); the energy band gap was estimated to be $3.05{\pm}0.5$ eV and the position of conduction band edge was close to those of $TiO_2$ and ZnO. The DSSC assembled with the $Sb_6O_{13}$ photoelectrode and a conventional ruthenium-dye (N719) exhibited the overall photo-current conversion efficiency of 0.74% ($V_{oc}$ = 0.76 V, $J_{sc}=1.99\;mAcm{-2}$, fill factor = 0.49) under AM 1.5, $100\;mWcm^{-2}$ illumination.

• Microbiology and Biotechnology Letters
• /
• v.8 no.3
• /
• pp.199-206
• /
• 1980

Some experiments on the citric acid production were carried out from soluble starch and molasses as raw materials. When soluble starch was used as substrate for the fermentation of citric acid by the strain M-80 which had assimilating ability of soluble starch in surface culture, the optimal culture media was 120g of soluble starch, 3.0g of (N $H_4$)$_2$S $O_4$, 2.0g of K $H_2$P $O_4$, 0.2g of MgS $O_4$.7$H_2O$, 1.5mg of F $e^{++}$, 1mg of Z $n^{++}$ and 20ml of methanol were added to 1 liter and optimal pH was 5.5. In about 8 days 61.8mg/ml of citric acid was produced. When treated molasses with potassium ferrocyanide was used as substrate for the fermentation of citric acid by the strain of M-315, the optimal condition in surface culture was 250g of molasses, 0.3g of N $H_4$N $O_3$, 0.05g of K $H_2$P $O_4$, 0.01g of MgS $O_4$.7$H_2O$, 0.5g of Potassium ferrocyanide and 30ml of methanol were added to 1.0 liter. On the other hand, the optimal condition in submersed culture was 250g of molasses, 0.3g of N $H_4$N $O_3$, 0.1g of K $H_2$P $O_4$, 0.01g of MgS $O_4$.7$H_2O$, 0.5g of potassium ferrocyanide, and 30m1 of methanol were added to 1.0 liter and optimal pH was all 5.0. After 9 days culture, 69.4mg/ ml, 39.6mg/ml of citric acid were separately produced in surface and submerged culture media.dia.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2012.05a
• /
• pp.86.1-86.1
• /
• 2012

나노재료와 나노기술의 연구개발 지원을 위하여 국가나노인프라인 나노종합팹센터에서 개발되고 있는 나노재료/나노현상의 실시간 관찰을 위한 SiN membrane chip 기술 및 나노그래핀 기반구축에 대한 최근 결과와 향후계획을 소개하고자 한다. 나노재료의 합성, 배열, 구조 등의 실시간 관찰을 가능하게 하기 위하여 제작된SiN membrane chip은 투과전자현미경(transmission electron microscope, TEM)에서 투명한 기판으로, 그 위에 나노재료를 합성, 배열하고 원하는 모양의 전극을 형성하여 나노재료 및 나노소자의 온도변화 및 전기적 특성 측정 등이 가능하다. 이러한 기술은 Ag, Sn, Cu 등 nano-cluster의 percolation 소자, SiN 및 Graphene 나노기공 소자, SiGe, BiTe, Si, ZnO 나노선 및 CNT의 내부구조변화, 상변화 등 다양한 나노재료/나노소자의 나노현상 관찰 및 해석에 적용되었다.

• Journal of the Semiconductor & Display Technology
• /
• v.10 no.2
• /
• pp.65-71
• /
• 2011

Properties of each layer in DSSC were investigated to improve solar cell characterstics. Also in this study, low costsolar simulator system is fabricated and used. Efficiency of DSSC is better in the case of thinner semiconductive layer, because thick semiconductive layer is acted as resistor. Sc-doped ZnO thin films showed better electrical property by proper donor doping effect. Among the dyes, DSSC containing N719 showed higher efficiency, because N719 have smaller electron affinity and shallow band gap.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.83-83
• /
• 2010

We report a new direct printing method, called liquid-mediated nanotransfer molding (LB-nTM), that uses a polar liquid-mediated transfer process. LB-nTM is based on the direct transfer of various materials from a stamp to a substrate via a liquid- bridge between the stamp and the substrate. This procedure can be adopted in automated printing machines that generate various material patterns with a wide range of feature sizes (as small as 60 nm) on diverse substrates. To demonstrate its usefulness, the LB-nTM method was applied to prepare ZnO-nanowire and TIPS-pentacene transistors.